Safranal-sorafenib combination therapy for liver cancer

TECHNICAL FIELD

The present invention relates to therapeutic formulations and methods for treating liver cancer including safranal and sorafenib.

BACKGROUND

Despite all efforts, more people are diagnosed with hepatocellular carcinoma (HCC); the most common type of primary liver cancer and the second leading cause of cancer-related death worldwide. Multiple risk factors contribute to HCC development including chronic hepatitis (B and C) infection that accounts for 70%-90% of HCC cases by providing a permissive environment for HCC development. Other HCC risk factors include alcoholism, non-alcohol fatty liver disease, iron overload, and environmental carcinogens. Early stages of HCC show no symptoms, thus most patients are diagnosed at advanced stages. In addition, HCC exhibits a high rate of recurrence after resection or ablation; and is considerably resistant to cytotoxic chemotherapy, with a very limited number of available treatments. Thus, alternative therapeutics are well justified and are desperately needed to treat HCC.

Chemotherapy is the most common treatment of cancer patients. HCC is however, chemo-resistant, and the side-effects of chemotherapy are typically exhausting to the patient. Sorafenib is the first anti-HCC drug approved by the U.S. Food and Drug Administration. It is a multikinase inhibitor that blocks tumor cells proliferation and angiogenesis. Although sorafenib is successful in treating early and mid HCC lesions, it is not efficient in advanced HCC cases. The common side effects of sorafenib are skin toxicity, diarrhea, hypertension, and bleeding.

Natural products have long been a part of folk medicine and have been playing an instrumental role in the development of anti-cancer drugs. Thanks to their nontoxicity and low-to-no associated side effects, 40% of FDA-approved therapeutic agents are natural-based components or their derivatives. Considering their great efficacy and low toxicity, natural products have been extensively studied and introduced as a chemopreventive therapy for many diseases including cancer. Medicinal plants have been suggested for cancer prevention and therapy for several reasons; they contain nutritional and anti-tumor compounds, are able to delay or prevent cancer onset, can boost the physiological status and the immune system, and most importantly, they represent a great alternative and/or adjuvant option to conventional cancer treatments by alleviating or even averting their side effects.

Saffron (the stigmas of the flower of Crocus sativus), is increasingly gaining attention as it contains many bioactive molecules with health promoting properties; including crocin, crocetin, picrocrocin, and safranal, Previous studies have reported the anti-cancer activity of saffron and its derivatives against a wide range of cancers. While saffron's derivatives have been reported to inhibit the growth of HeLa cells, safranal has specifically been shown to exert potent anti-inflammatory, antioxidant and anti-cancer properties and was found to induce apoptosis in both alveolar human lung cancer A549, and human prostate cancer PC-3 cell lines. Despite all its anti-tumor activities, the mechanism through which safranal exerts its anti-cancer effect is yet to be fully understood.

Hence, it would be advantageous to understand the mechanism through which safranal exerts anti-cancer effects so it may be developed into an effective treatment for liver and other cancer types, either alone or in combination with chemotherapeutical agents.

SUMMARY OF THE EMBODIMENTS

In accordance with a first aspect of the invention, the present application provides a therapeutic combination of drugs for the treatment of a liver cancer. The combination includes: safranal or a pharmaceutically acceptable pro-drug thereof, and sorafenib. In representative embodiments, the pro-drug is selected from the group consisting of a safranal salt, hydrate, hemiacetal, acetal, thioacetal, silylether, tautomer, isomer, and combinations thereof. The safranal and the sorafenib may be compounded together in a same unitary pharmaceutical composition including both compounds. Alternatively, the safranal and the sorafenib may be provided in the form of separate pharmaceutical compositions.

In accordance with a second aspect of the invention, the present application provides a method of treating, suppressing, or reducing the severity of a liver cancer in a subject. The method includes administering to the subject the therapeutic combination of safranal and sorafenib. In representative embodiments, the liver cancer is selected from the group consisting of hepatocellular carcinoma (HCC), fibrolamellar HCC, cholangiocarcinoma, angiosarcoma, a metastatic liver cancer, and combinations thereof. In an embodiment, the mass-to-mass ratio of safranal:sorafenib administered to the subject is in the range of about 50:1 to about 1:1. In a further embodiment, the mass-to-mass ratio of safranal:sorafenib administered to the subject is in the range of about 25:1 to about 1:1. In exemplary embodiments, the mass-to-mass ratio of safranal:sorafenib is based on the respective amounts of safranal and sorafenib administered to the subject in a single day, a single week, 14 days, 21 days, or 28 days. In an embodiment, the amount of the safranal or pro-drug thereof is from about 10 mg/day to about 1000 mg/day per kg body weight of the subject. In a further embodiment, the amount of the safranal or pro-drug thereof is from about 200 mg/day to about 750 mg/day per kg body weight of the subject. In an additional embodiment, the amount of the safranal or pro-drug thereof is from about 250 mg/day to about 500 mg/day per kg body weight of the subject. The safranal may be administered to the subject prior to the sorafenib, concurrently with the sorafenib, or after the sorafenib. In an embodiment, the sorafenib is administered to the subject in an amount of about 800, 600, 400, or 200 mg/day. In a further embodiment, the sorafenib is administered at an effective dose that is at least 50% to at most 90% or more below the dose needed to be effective in the absence of safranal administration. The liver cancer may have primary or secondary resistance to sorafenib.

In accordance with a third aspect of the invention, the present application provides a kit for the treatment of liver cancer. The kit includes a first pharmaceutically acceptable composition of safranal, a second pharmaceutical composition of sorafenib, and instructions for the administration of the first composition and second composition for treatment of liver cancer. In representative embodiments, the liver cancer is selected from the group consisting of hepatocellular carcinoma (HCC), fibrolamellar HCC, cholangiocarcinoma, angiosarcoma, a metastatic liver cancer, and combinations thereof.

BRIEF DESCRIPTION OF THE FIGURES

The invention can be better understood with reference to the following figures and description. The components in the figures are not necessarily to scale and are not intended to accurately represent molecules, cells, cell organelles, tissues, or their interactions, emphasis instead being placed upon illustrating the principles of the invention.

FIG. 1 provides the experimental design of an in vivo study conducted to establish a hepatocarcinogenesis model.

FIG. 2 provides representative images of rat livers demonstrating the anti-tumorigenic properties of safranal. Whole livers were excised from control rats (PBS), DEN-induced hepatic neoplasia in rats untreated (HCC group) or treated with sorafenib (HCC SB), safranal (HCC SF) individually or combined (HCC SF SB).

FIG. 3 provides a quantitative analysis of the number of liver nodules from DEN-induced hepatic neoplasia in rats untreated (HCC group) or treated with sorafenib (HCC+SB), safranal (HCC+SF) individually or combined (HCC+SF+SB).

FIG. 4 provides representative images of hematoxylin and eosin-stained sections (arrows point to representative areas of AHF), n=6. The sections were of livers from control rats (PBS), DEN-induced hepatic neoplasia in rats untreated (HCC group) or treated with sorafenib (HCC SB), safranal (HCC SF) individually or combined (HCC SF SB).

FIG. 5 provides a quantitative analysis of the area of neoplastic foci for histology from DEN-induced hepatic neoplasia in rats that were untreated (HCC group) or treated with sorafenib (HCC+SB), safranal (HCC+SF) individually or combined (HCC+SF+SB).

FIG. 6 provides representative images of reticulin-stained sections (arrows point to reticulin fibers). The sections were taken from control rats (PBS), DEN-induced hepatic neoplasia in rats untreated (HCC group) or treated with sorafenib (HCC SB), safranal (HCC SF) individually or combined (HCC SF SB).

FIGS. 7A and 7B demonstrate that safranal inhibits proliferation of induced hepatic neoplasia.

FIG. 7A is a western blot analysis of the proliferation-related protein (PCNA) on DEN-induced hepatic neoplasia in rats untreated (HCC group) or treated with sorafenib (HCC SB), safranal (HCC SF) individually or combined (HCC SF+SB).

FIG. 7B reports the quantification of each band intensity from FIG. 7A. Quantification was carried out using ImageJ, normalized in relative to the total protein from the liver.

FIG. 8 is a western blot analysis of the cell cycle-related proteins (Cdk1, Cyclin B1, Cdc25B) on DEN-induced hepatic neoplasia in rats untreated (HCC group) or treated with sorafenib (HCC SB), safranal (HCC SF) individually or combined (HCC SF+SB).

FIG. 9 reports the quantification of proteins of G2/M cell cycle arrest of induced hepatic neoplasia. Each band intensity from FIG. 8 was quantified using ImageJ, normalized in relative to the total protein from the liver. Results are expressed as mean.+-.S.D for (n=4) animals in each group. Significance was determined by one-way ANOVA followed by Tukey's post hoc analysis (P<0.05).

FIG. 10 is a western blot analysis establishing that safranal induces intrinsic apoptosis of induced hepatic neoplasia. The western blot analyzes the intrinsic apoptosis-related proteins (Bcl-2, Bax, Pro-Caspase-9, Pro-Caspase-3, PARP) on DEN-induced hepatic neoplasia in rats untreated (HCC group) or treated with sorafenib (HCC SB), safranal (HCC SF) individually or combined (HCC SF+SB).

FIG. 11 provides the results of a quantification of Bax, Bcl-2, and the Bax/Bcl ratio from the bands of the western blot of FIG. 10. Each band intensity was quantified using ImageJ, normalized in relative to the total protein from the liver. Results are expressed as mean.+-.S.D for (n=4) animals in each group. Significance was determined by one-way ANOVA followed by Tukey's post hoc analysis (P<0.05).

FIG. 12 provides the results of a quantification of Pro-Caspase-9, Pro-Caspase-3, and PARP from the bands of the western blot of FIG. 10. Each band intensity was quantified using ImageJ, normalized in relative to the total protein from the liver. Results are expressed as mean.+-.S.D for (n=4) animals in each group. Significance was determined by one-way ANOVA followed by Tukey's post hoc analysis (P<0.05).

FIG. 13 is a table reporting human equivalent dose (HED) dosage factors based on body surface area of other species according to data obtained from Food and Drug Administration draft guidelines.

FIG. 14 provides a heatmap of gene expression profiles for all the groups. Hierarchical cluster analysis represents the mean of the triplicate for each group. Raw data were centred and unit variance scaling was applied. Groups were clustered by maximum distance and complete linkage. Expression levels are colored red for high expression and grey for low expression.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

The present invention is at least in part based on the finding that safranal and sorafenib exert a synergistic anticancer effect on HCC in laboratory rats. This therapeutic effect can be put to use in the treatment of liver cancer. Compared with monotherapy with sorafenib alone, treatment with safranal in combination with sorafenib targeting multiple signaling pathways offers a better treatment alternative potentially abolishing resistance, feedback activation, and compensatory activation of survival pathways. Without being bound to any particular theory, it is believed that safranal may sensitize hepatic cells to sorafenib's effect by further decreasing the expression of cell cycle-related proteins than sorafenib alone. This finding can be described as a synergy, or greater than additive effect, that is specific to certain combinations of sorafenib and safranal, and liver cancer, with a higher improvement than with monotherapy with sorafenib.

In exemplary embodiments, provided herein are therapeutic combinations of drugs including a first amount of safranal (or its pharmaceutically acceptable pro-drug) and a second amount of sorafenib. Essentially, the combination of safranal and sorafenib represents a therapeutic combination that may be more efficacious than either agent alone or the simple sum of the two agents. In addition, different doses of the combination may lead to additional gains in treatment of the liver cancer than either safranal or sorafenib alone. Accordingly, in some embodiments, the present application provides unexpectedly advantageous methods and compositions for treating liver cancer, whereby sorafenib and a safranal are administered in a ratio that is particularly effective (e.g., synergistic or more than additive).

Safranal

In several embodiments, the present invention includes the use of safranal. Safranal is a molecule having the IUPAC name 2,6,6-trimethyl-1,3-cyclohexadiene-1-carboxaldehyde and its structural formula is:

##STR00001##

Safranal includes an alpha, beta, gamma, delta-unsaturated aldehyde group and is therefore capable of forming hemiacetals, acetals, thioketals, silyl ethers, and other derivatives resulting from nucleophilic addition reactions to the beta- or delta-carbon of the unsaturation. In instances where the safranal derivatives are pharmaceutically acceptable and easily cleavable under physiological conditions, one or more derivative may be administered to the patient as a pro-drug of safranal itself. The term "pharmaceutically acceptable safranal derivative", in this respect, refers to the pharmaceutically acceptable and easily cleavable groups of safranal, including hemiacetals, acetals, thioketals, silyl ethers, and nucleophilic addition products. These pro-drugs can be prepared in situ in the administration vehicle or in the dosage form manufacturing process, or by separately reacting safranal with a suitable reactant, and isolating the derivative thus formed during subsequent purification. Other derivatives that may serve as pro-drugs include pharmaceutically acceptable salts and hydrates. Therapeutically effective tautomers and isomers of safranal are also contemplated. Unless otherwise specified, the terms "composition including safranal" and "formulation of safranal" as used herein are intended to cover compositions and formulations including safranal itself, its pro-drugs such as pharmaceutically acceptable hemiacetals and acetals, pharmaceutically acceptable tautomers and isomers, and pharmaceutically acceptable salts thereof.

A composition including safranal may be specially formulated for administration in solid or liquid form, including those adapted for the following: (1) oral administration, for example, drenches (aqueous or non-aqueous solutions or suspensions), tablets, e.g., those targeted for buccal, sublingual, and systemic absorption, boluses, powders, granules, pastes for application to the tongue; (2) parenteral administration, for example, by subcutaneous, intramuscular, intravenous or epidural injection as, for example, a sterile solution or suspension, or sustained-release formulation; (3) topical application, for example, as a cream, ointment, or a controlled-release patch or spray applied to the skin; (4) intravaginally or intrarectally, for example, as a pessary, cream or foam; (5) sublingually; (6) ocularly; (7) transdermally; or (8) nasally.

Wetting agents, emulsifiers and lubricants, such as sodium lauryl sulfate and magnesium stearate, as well as coloring agents, release agents, coating agents, sweetening, flavoring and perfuming agents, preservatives and antioxidants can also be present in the compositions.

Formulations of safranal include those suitable for parenteral (including subcutaneous, intravenous, intramedullary, intraarticular, intramuscular, or intraperitoneal injection), rectal, topical, transdermal, or oral (for example, in capsules, suspensions, or tablets) administration. The formulations may conveniently be presented in unit dosage form and may be prepared by any methods well known in the art of pharmacy. The amount of safranal or its pharmaceutically acceptable pro-drugs which can be combined with a carrier material to produce a single dosage form will vary depending upon the subject being treated and the particular mode of administration. The amount of an active ingredient which can be combined with a carrier material to produce a single dosage form will usually be that amount of the compound which produces a therapeutic effect. Usually, out of one hundred percent, this amount will range from about 1 wt % to about 99 wt % of active ingredient, preferably from about 5 wt % to about 70 wt %, most preferably from about 10 wt % to about 30 wt %.

Regardless of the route of administration selected, safranal or its pro-drugs may be formulated into pharmaceutically-acceptable dosage forms by conventional methods known to those of skill in the art. Safranal may be formulated for administration in any convenient way for use in human or veterinary medicine, by analogy with other pharmaceuticals.

Sorafenib

In various embodiments, the present invention includes the use of sorafenib, for example in the form of sorafenib tosylate as well as other pharmaceutically acceptable forms, salts, and esters of sorafenib. Sorafenib is commercially available as NEXAVAR.RTM., which is the tosylate salt of sorafenib. Sorafenib tosylate has IUPAC chemical name 4-(4-{3-[4-Chloro-3 (trifluoromethyl)phenyl]ureido} phenoxy) N-methylpyridine-2-carboxamide 4-methylbenzenesulfonate and its structural formula is:

##STR00002##

The recommended daily dose of sorafenib tosylate is 800 mg administered as 400 mg (two tablets) orally twice daily. However, treatment interruption and/or dose reduction may be needed to manage suspected adverse drug reactions. In such instances, the dose may be reduced to 400 mg once daily or to 400 mg every other day. A person of ordinary skill will understand that sorafenib dosage and administration can follow medically approved guidelines, as well medically accepted deviations or alterations to such guidelines.

Liver Cancer

In one aspect, the present invention provides methods for the treatment of liver cancer cells, including cancer cells in a subject or in vitro treatment of isolated cancer cells. If the cancer cells are in a subject, the subject may be a primate, such as a human, with liver cancer. The subject may be a mammal. The subject may be an adult human (i.e., 18 years or older), or a juvenile human (i.e., less than 18 years old). In various embodiments, the liver cancer may be a hepatocellular carcinoma (HCC), a fibrolamellar HCC, a cholangiocarcinoma, an angiosarcoma, or a metastatic liver cancer.

In some embodiments, the liver cancer is not resistant to sorafenib. Alternatively, the liver cancer may have primary or secondary resistance to sorafenib. The subject can be a responder to sorafenib in the absence of the safranal. The subject can be a non-responder to sorafenib in the absence of safranal. In some embodiments, the subject has undergone a prior treatment with sorafenib lasting at least 1, 2, 4, 6, 8, 10 months or longer. In other embodiments, the subjects are patients who have experienced one or more significant adverse side effect to sorafenib and therefore require a reduction in dose.

In some embodiments, the liver cancer is intermediate, advanced, or terminal stage. The liver cancer can be metastatic or non-metastatic. The liver cancer may be resectable or unresectable. The liver cancer may include a single tumor, multiple tumors, or a poorly defined tumor with an infiltrative growth pattern (into portal veins or hepatic veins). The liver cancer may include a fibrolamellar, pseudoglandular (adenoid), pleomorphic (giant cell), or clear cell pattern. The liver cancer may include a well differentiated form, and tumor cells resemble hepatocytes, form trabeculae, cords, and nests, and/or contain bile pigment in cytoplasm. The liver cancer may include a poorly differentiated form, and malignant epithelial cells are discohesive, pleomorphic, anaplastic, and/or giant. In some embodiments, the liver cancer may be associated with hepatits B, hepatitis C, cirhhosis, or type 2 diabetes.

In some embodiments, the subject is a human having an Eastern Cooperative Oncology Group (ECOG) performance status .ltoreq.2. In some embodiments, the subject is a human having acceptable liver function defined as (i) total bilirubin .ltoreq.1.5 times the upper limit of normal (ULN); for patients with hepatocellular carcinoma only, total bilirubin .ltoreq.3 mg/dL (i.e., Child-Pugh Score for bilirubin is no greater than 2); (ii) aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) .ltoreq.5.times.ULN; or (iii) acceptable renal function: Serum creatinine .ltoreq.1.5 times the ULN, or calculated creatinine clearance .gtoreq.60 mL/min/1.73 m.sup.2 for patients with creatinine levels above 1.5 times the institutional normal.

In some embodiments, the subject is a human having acceptable hematological status defined as (i) absolute Neutrophil Count (ANC) .gtoreq.1500 cells/mm.sup.3; (ii) platelet count .gtoreq.100,000 plts/mm.sup.3 (without transfusion); .gtoreq.75,000 pits/mm.sup.3 for patients with hepatocellular carcinoma only; or (iii) hemoglobin .gtoreq.9 g/dL.

In some embodiments, the subject is a human having a prothrombin time (PT) or International Normalized Ratio (INR) .ltoreq.1.25.times.ULN; INR <1.7 or prothrombin time (PT) or <4 seconds above ULN (i.e., Child-Pugh Score is no greater than 1 for the coagulation parameter); or serum albumin >2.8 g/dL (i.e., Child-Pugh Score for albumin is no greater than 2).

Combination Therapy

Combination therapy or polytherapy is the use of more than one medication or other therapy, as opposed to monotherapy, which is any therapy taken alone. In one aspect of the present invention, provided herein is a therapeutic combination of drugs for the treatment of liver cancer, the combination including safranal and sorafenib. In an example embodiment of the combination, the safranal and sorafenib are compounded together in a same unitary pharmaceutical composition including both compounds. In another example embodiment, the safranal and sorafenib are in separate pharmaceutical compositions. Also provided are methods for treating, suppressing, or reducing the severity of a liver cancer in a subject by administering to the subject a therapeutic amount of the combination.

In some embodiments, the therapeutic combination refers to using specific combinations (e.g., ratios and/or dosing schedules) of safranal and sorafenib. More particularly, the invention provides therapeutic combinations and methods for treating liver cancer where the safranal and sorafenib are administered in a ratio that is particularly effective (e.g., synergistic or more than additive). In representative embodiments, the ratio, that is, the mass-to-mass ratio of safranal:sorafenib is about 50 to 1, 40 to 1, 30 to 1, 25 to 1, 20 to 1, 10 to 1, 5 to 1, 2 to 1, 1 to 2, 1 to 5, 1 to 10, 1 to 20, 1 to 30, 1 to 40, or 1 to 50. In some embodiments, the ratio is, or is at least, about 1, 2, 5, 10, 12, 15, 20, or 50. In some embodiments, the ratio is less than about 5, 10, 15, 20, 30, 40, 50, 60, or 70. Example weight-to-weight ratios are about 1, 2, 5, 8, 10, 15, 20, 25, 30, 40, and 50.

The mass-to-mass ratio of safranal:sorafenib can be measured over different periods of time. For example, the mass ratio may be based on the respective amounts of safranal and sorafenib administered to the subject in a single day, a single week, 14 days, 21 days, or 28 days.

The sorafenib dosing amount and/or schedule can follow clinically approved, or experimental, guidelines. In various embodiments, the dose of sorafenib is about 800, 600, 400, or 200 mg/day. A 200 mg/day dose can be administered as a 400 mg dose every other day.

Likewise the safranal dosing amount and/or schedule can follow clinically approved, or experimental, guidelines. Also, the data obtained from animal studies may be used in formulating a safranal range of dosage for use in humans. For example, effective dosages achieved in one animal species may be extrapolated for use in another animal, including humans, as illustrated in the conversion table of FIG. 13 where human equivalent dose (HED) dosage factors based on body surface area of other species are reported. (Nair and Jacob, 2016). In exemplary embodiments, the dose of safranal fall in the range from about 0.001, 0.01, 0.1, 0.5, 1, 10, 15, 20, 25, 50, 100, 200, 300, 400, 500, 600, or 750 to about 1000 mg/day per kg body weight of the subject. In certain embodiments, the dose of safranal will typically be in the range of about 100 mg/day to about 1000 mg/day per kg body weight of the subject, specifically in the range of about 200 mg/day to about 750 mg/day per kg, and more specifically in the range of about 250 mg/day to about 500 mg/day per kg. In an embodiment, the dose is in the range of about 50 mg to about 250 mg per kg/day. In a further embodiment, the dose in the range of about 100 mg to about 200 mg per kg. In an embodiment, the dose is in the range of about 15 mg/day to 60 mg/day per kg. In a further embodiment, the dose is in the range of about 20 mg/day to 50 mg/day per kg. In an additional embodiment, the dose is in the range of about 25 mg/day to 45 mg/day per kg.

The dose of safranal can be set, within a therapeutically effective range, based upon a selected ratio and dose of sorafenib. As discussed above, the ratio can be determined using the amount of sorafenib administered to a subject over a single day, a single week, 14 days, 21 days, or 28 days.

In some embodiments, the safranal is administered to the subject in 1, 2, 3, 4, 5, 6, or 7 daily doses over a single week (7 days). The safranal may be administered to the subject in 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14 daily doses over 14 days. The safranal may be administered to the subject in 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or 21 daily doses over 21 days. The safranal may be administered to the subject in 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, or 28 daily doses over 28 days.

In various embodiments, the safranal is administered for: 2 weeks (total 14 days); 1 week with 1 week off (total 14 days); 3 consecutive weeks (total 21 days); 2 weeks with 1 week off (total 21 days); 1 week with 2 weeks off (total 21 days); 4 consecutive weeks (total 28 days); 3 consecutive weeks with 1 week off (total 28 days); 2 weeks with 2 weeks off (total 28 days); 1 week with 3 consecutive weeks off (total 28 days).

In further embodiments, the safranal is: administered on day 1 of a 7, 14, 21 or 28 day cycle; administered on days 1 and 15 of a 21 or 28 day cycle; administered on days 1, 8, and 15 of a 21 or 28 day cycle; or administered on days 1, 2, 8, and 15 of a 21 or 28 day cycle. The safranal can be administered once every 1, 2, 3, 4, 5, 6, 7, or 8 weeks.

A course of safranal-sorafenib therapy can be continued until a clinical endpoint is met. In some embodiments, the therapy is continued until disease progression or unacceptable toxicity occurs. In some embodiments, the therapy is continued until achieving a pathological complete response rate defined as the absence of liver cancer (e.g., HCC). In some embodiments, the therapy is continued until partial or complete remission of the liver cancer. Administering the safranal and the sorafenib to a plurality of subject having liver cancer may increase the Overall Survival (OS), the Progression free Survival (PFS), the Disease Free Survival (DFS), the Response Rate (RR), the Quality of Life (QoL), or a combination thereof.

In various embodiments, the treatment reduces the size and/or number of the liver cancer tumor(s). The treatment can prevent the liver cancer tumor(s) from increasing in size and/or number. The treatment can prevent the liver cancer tumor(s) from metastasizing.

In the methods of the invention, administration of the safranal and sorafenib is not limited to any particular delivery system and may include, without limitation, one or more of parenteral (including subcutaneous, intravenous, intramedullary, intraarticular, intramuscular, or intraperitoneal injection), rectal, topical, transdermal, or oral (for example, in capsules, suspensions, or tablets). Administration to an individual may occur in a single dose or in repeat administrations, and in any of a variety of physiologically acceptable pro-drug or salt forms, and/or with an acceptable pharmaceutical carrier and/or additive as part of a pharmaceutical composition. Physiologically acceptable salt forms and standard pharmaceutical formulation techniques, dosages, and excipients are well known to persons skilled in the art. Additionally, effective dosages achieved in one animal may be extrapolated for use in another animal, including humans, using conversion factors known in the art.

The combination therapies of the invention are not specifically limited to any particular course or regimen and may be employed separately or in conjunction with other therapeutic modalities (e.g., chemotherapy or radiotherapy).

In some embodiments, the safranal is administered prior to the sorafenib, concurrently with the sorafenib, after the sorafenib, or a combination thereof. The safranal may be administered systemically or regionally.

A combination therapy in accordance with the present invention can include additional therapies (e.g., pharmaceutical, radiation, and the like) beyond the safranal and sorafenib. Similarly, the present invention can be used as an adjuvant therapy (e.g., when combined with surgery). In various embodiments, the subject is also treated by surgical resection, percutaneous ethanol or acetic acid injection, transcatheter arterial chemoembolization, radiofrequency ablation, laser ablation, cryoablation, focused external beam radiation stereotactic radiotherapy, selective internal radiation therapy, intra-arterial iodine-131-lipiodol administration, and/or high intensity focused ultrasound.

The combination of the safranal and sorafenib can be used as an adjuvant, neoadjuvant, concomitant, concurrent, or palliative therapy. The combination of the safranal and sorafenib can be used as a first line therapy, second line therapy, or crossover therapy.

In some embodiments, the therapeutically effective dose of sorafenib is reduced through combination with safranal. For example, the daily, weekly or monthly dose of sorafenib can be reduced by at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or more relative to the maximum recommended dose or the maximum tolerated dose. In other embodiments, sorafenib is administered at an effective dose that is at least 30%, 40%, 50%, 60%, 70%, 80%, 90% or more below the dose needed to be effective in the absence of safranal administration. In some embodiments, the IC50 of sorafenib is reduced by at least 2-, 4-, 5-, 10-, 20-, 30-, 40-, 50-, or 100-fold relative to the IC50 in the absence of safranal.

Kits

The present invention also provides kits for treating liver cancer. For example, a kit may include one or more pharmaceutical compositions of safranal and sorafenib as described above. The compositions may be pharmaceutical compositions comprising a pharmaceutically acceptable excipient. In other embodiments involving kits, there is provided a kit including a first pharmaceutically acceptable composition including safranal, a second pharmaceutically acceptable composition including sorafenib, and optionally instructions for their use in the treatment of liver cancer. In still other embodiments, there is provided a kit including one more pharmaceutical compositions and one or more devices for accomplishing administration of such compositions. For example, a subject kit may comprise a pharmaceutical composition and catheter for accomplishing direct intraarterial injection of the composition into a cancer. In an embodiment, the device is an intraarterial catheter.

Experimental Results

In vivo HCC model was successfully induced in male Wistar rats, then treated with sorafenib alone, safranal alone, and with both safranal and sorafenib. Data analysis showed the efficiency of safranal as a drug and an adjuvant in restoring liver function. Presented results also showed safranal's inhibitory role of cell cycle, and its proapoptotic capacity suggesting safranal's high potential as a novel anti-cancer drug.

Male Wistar rats, weighing around 160 gm, were used in this study. Rats were provided by the animal research facility at the College of Medicine and Health Sciences, United Arab Emirates University. Rats were housed under a 12-hour light/dark cycle at 24-26.degree. C. They were maintained on a standard laboratory animal diet with food and water ad libitum.

Experimental Design

A modified version of the protocol described by DePeralta et al. (2016) and Schiffer et al. (2005) was used here to establish the hepatocarcinogenesis model. As seen in FIG. 1, animals were divided into five groups, each group having eight animals labelled as follows: control phosphate buffered saline (PBS), HCC, HCC+sorafenib, HCC+safranal, and HCC+safranal+sorafenib.

On the first 15 weeks, the control PBS group was treated with 1.times.PBS, whereas the experimental groups were given an intraperitoneal injection (IP) of 50 mg/kg of diethylnitrosoamine (DEN, Sigma Aldrich), a widely used chemical for inducing cancer, once a week. DEN was diluted with 1.times.PBS. Following a one-week break (week 16), the next three weeks (weeks 17 to 19) of treatment commenced. All drugs were administrated by oral gavage. All doses were chosen according to literature (Alsaied et al., 2014; Karafakio lu et al., 2017). For the HCC+sorafenib group, the drug (Carbosynth Limited) was administered at a dose of 10 mg/kg, five days a week. For the HCC+safranal group, the drug (Sigma Aldrich) was administered at a dose of 200 mg/kg, five days a week. For the HCC+safranal+sorafenib group, the drugs were administered at a dose of 200 mg/kg safranal+10 mg/kg sorafenib, five days a week. Both safranal and sorafenib were diluted with 1.times.PBS and drops of Tween 80. The oral LD.sub.50 of safranal is 5.53 mL/kg in male rats (Hosseinzadeh et al., 2013). After 24-hours from last treatment, the rats were euthanized by mild diethyl ether and dissected in equal conditions. Blood and whole liver were collected.

Blood Samples

Rats were euthanized then blood was collected by decapitation and processed for later investigation. The blood was collected in collection tubes (BD Vacutainer) and serum was separated by centrifugation at 1200.times.g for 10 minutes. Serum was collected and flash frozen immediately then stored at -80.degree. C. for further analysis.

Biochemical Analysis

Alanine Transaminase (ALT), and Aspartate Aminotransferase (AST) assays were performed using commercial kits (Abcam), according to the protocol provided. ALT and AST activities were measured spectrophotometrically using Epoch by BioTek.

Liver Samples

Part of the liver was immediately flash frozen in liquid nitrogen then stored at -80.degree. C. for further analysis. The other part was kept in 10% neutral buffered formalin at room temperature for histology.

Histopathological Examination

Liver sample specimens were fixed in 10% neutral buffered formalin, dehydrated in a series of graded ethanol, embedded in paraffin blocks, and cut into 3 .mu.m-thick sections. To detect histopathological changes, sections were stained with hematoxylin and eosin (H&E), and reticulin stain kit according to the protocol provided (Abcam), then examined under light microscope (Ozkececi et al., 2016). Blinded examination of tissue samples was carried out by a pathologist from Tawam Hospital--United Arab Emirates.

Western Blotting

One hundredth gm (10 mg) liver was homogenized using 200 .mu.l RIPA buffer (Sigma Aldrich) mixed with 2 .mu.l protease inhibitor and 2 .mu.l phosphatase inhibitor (Sigma Aldrich), and centrifuged at 4.degree. C., 15,000 rpm for 15 minutes. Whole cell lysate was taken and stored at -80.degree. C. Protein concentration was measured by Pierce BCA Protein Assay Kit with Promega GloMax Discover. A total of 35 .mu.g of protein was loaded on a sodium dodecyl sulfate-polyacrylamide gel electrophoresis gel. The gel was then transferred to polyvinylidene difluoride membrane. The membrane was then blocked with 5% BSA in TBST for one hour at room temperature. Membranes were incubated with anti-Proliferating Cell Nuclear Antigen (PCNA), anti-PolyADP-ribose Polymerase (PARP), anti-caspase-3 (Cell Signaling Technology Inc.), anti-caspase-9 (Novus Biologicals), anti-Bax, anti-Bcl-2 (Santa Cruz), anti-Cdk1, anti-Cyclin B1, anti-Cdc25B (Cell Signaling Technology Inc.) over night at 4.degree. C., then with HRP conjugated secondary, anti-mouse or anti-rabbit, antibody (Cell Signaling Technology Inc.) for one hour at room temperature. All primary and secondary antibodies were diluted in 5% BSA in TBST. Blots were incubated in WesternSure PREMIUM Chemiluminescent Substrate for antibodies' detection. Signal was visualized using Bio-Rad ChemiDoc XRS+ System. Band density and quantification was done using ImageJ (Amin et al., 2011). Total protein was used as a loading control and stained using SYPRO Ruby protein gel stain according to the protocol provided (Thermo Fisher Scientific) (Aldridge et al., 2008; Hu et al., 2016).

Total Protein as a Loading Control

Due to technical reasons, total protein was used in this study as the loading control instead of the other common markers like GAPDH, .beta.-tubulin, and .beta.-actin. A study published in 2003 used liver samples from normal, cirrhotic, and HCC tissues to inspect the housekeeping genes. Ten internal controls were used, and their expressions were determined using RT-PCR. Results showed that all internal control genes varied more than a 2-fold, and the commonly used genes like GAPDH and .beta.-actin varied from 7- to 23-fold, precisely in tumor tissue (Kim & Kim, 2003). Following studies then tried to find an alternative way for this issue. Total protein, depending on the amount of total protein rather than a single protein, served as a better control for colorectal cancer and HCC compared with different common housekeeping proteins. Also, testing the signal's linearity with the loading amounts was preserved in total protein, while in the other housekeeping proteins it was lost (Aldridge et al., 2008; Hu et al., 2016). Due to technical problems with all common internal controls, a protocol that was mentioned by Aldridge et al. (2008) and Hu et al. (2016) was followed.

Results

Several enzymes are released from hepatocytes into the blood and are measured in the blood serum to test the efficiency of liver function, ALT and AST are the most common enzymes. The more severe the liver is damaged, the higher their serum levels get. Together, they are considered the best markers for liver injury (Liu et al., 2012). In addition to serum, the whole liver tissues were collected and properly stored for further histological and immunoblotting analyses. In histological examination, liver tissues were processed and stained for final imaging using the microscope (Martin, 2015). To detect markers of specific pathways, selected proteins were targeted using western blotting.

Biochemical Analysis

As shown in Table 1, ALT (P<0.05) and AST levels were elevated in HCC group as compared to control group, thus indicating liver damage. Treatment with safranal and with both safranal+sorafenib significantly (P<0.05) decreased ALT levels in the treated groups as compared to HCC group. Safranal and the combination therapy caused a significance decrease (P<0.05) as compared to sorafenib alone (HCC+sorafenib). Values are expressed as mean.+-.SEM of six rats per group (n=6). Activity is expressed as mU/ml for ALT and AST. Significance was determined by one-way ANOVA followed by Tukey's post hoc analysis (a versus PBS, b versus HCC, c versus HCC+Sorafenib; P<0.05).

TABLE-US-00001 TABLE 1 Control PBS HCC HCC + sorafenib HCC + safranal HCC + safranal + sorafenib ALT 7.76 .+-. 0.38 14.10 .+-. 0.15.sup.a* 13.42 .+-. 0.22 10.93 .+-. 0.29.sup.b*,c* 9.55 .+-. 0.61.sup.b*,c* AST 9.00 .+-. 0.39 10.18 .+-. 1.69 11.14 .+-. 0.62 7.80 .+-. 2.02 10.98 .+-. 0.50

As the results show in Table 1, treatment with safranal decreased the elevation of ALT comparing to HCC group (P<0.05) with a higher efficiency of safranal alone and the synergic group (HCC+safranal+sorafenib) over sorafenib alone (P<0.05). This highlights the efficiency of safranal and its potential in combination therapy. The insignificant change of AST can be explained as ALT is more diagnostic enzyme found exclusively in the liver, while AST is not just found in the liver, but also in the muscles. AST is also cleared from the liver twice as fast as ALT, therefore ALT level is increased more than AST after liver injury (Lui, 2018).

Anti-tumorigenic and Anti-proliferative Activities of Safranal on DEN Induced Rat Liver Tumors

Liver Gross

FIG. 2 includes representative images of livers on week 20 to demonstrate the antitumorigenic effect of safranal (n=6). Whole liver excised from control rats (PBS), DEN-induced hepatic neoplasia in rats untreated (HCC group) or treated with sorafenib (HCC SB), safranal (HCC SF) individually or combined (HCC SF SB). Control PBS liver shows normal liver structure and color with no macroscopic lesions. The treatments showed "lesser levels of damaged livers" compared to livers from HCC group. DEN caused lesions and rough liver surface and caused abnormality in liver color in HCC animals. Drug treatments of HCC rats restored to variable degrees the normal liver architecture where lesions were evidently less in drug-treated groups.

FIG. 3 provides a quantitative analysis of the number of liver nodules from DEN-induced hepatic neoplasia in rats untreated (HCC group) or treated with sorafenib (HCC+SB), safranal (HCC+SF) individually or combined (HCC+SF+SB). Significance was determined by one-way ANOVA followed by Tukey's post hoc analysis (P<0.05). Treatments with safranal (HCC+safranal) and with both safranal and sorafenib (HCC+safranal+sorafenib) reduced lesions comparing to HCC animals, safranal also dramatically decreased lesions comparing to treatment with sorafenib alone (HCC+sorafenib).

Histology

FIG. 4 includes representative images of hematoxylin and eosin-stained sections (arrows point to representative areas of AHF), n=6. Sections were taken from: control rats (PBS), DEN induced hepatic neoplasia in rats untreated (HCC group) or treated with sorafenib (HCC SB), safranal (HCC SF) individually or combined (HCC SF SB). The structure of tissues and cells need to be stained in order to be visible. Cellular components are normally stained with a different color for proper distinction and analysis. Hematoxylin stains nucleic acids (nucleus) with blue color. Eosin stains proteins (cytoplasm) with pink color. The stain reveals plentiful structural and functional information (Fischer et al., 2008). Normal structure and histology of liver as seen in the control group where the liver is organized into hexagonally shaped lobules with the central vein at lobular centers. Hepatocytes are arranged in single-cell thick plates that radiate out from the central vein. In the animal model that has been developed in this study, macroscopic nodules were observed in the livers of mainly DEN-induced groups (see FIG. 2). However, microscopic histological examination of livers of rats in DEN-induced group showed clear neoplastic changes such as altered hepatocellular foci (AHF). In the present study, AHF are usually distinguished as delineated areas of hepatocytes with altered staining properties. Treatment with safranal either alone or in combination with sorafenib seem to enhance the restoration of the normal architecture of the liver in DEN-treated groups.

FIG. 5 provides a quantitative analysis of the area of neoplastic foci for histology from DEN-induced hepatic neoplasia in rats that were untreated (HCC group) or treated with sorafenib (HCC+SB), safranal (HCC+SF) individually or combined (HCC+SF+SB). Significance was determined by one-way ANOVA followed by Tukey's post hoc analysis (P<0.05). The analysis shows that safranal either alone or in combination with sorafenib seems to enhance (P<0.05) the restoration of the normal architecture of the liver in DEN-treated groups.

Reticulin Staining

FIG. 6 provides representative light microscope images of reticulin-stained sections (arrows point to reticulin fibers). The sections were taken from control rats (PBS), DEN-induced hepatic neoplasia in rats untreated (HCC group) or treated with sorafenib (HCC SB), safranal HCC SF) individually or combined (HCC SF SB). Control PBS liver shows normal liver morphology and defined reticular fibers. Liver sections from HCC animals show that DEN has caused reticular fiber breakage indicating hepatic neoplasia diagnosis. Treatment with safranal (HCC+safranal) and with both safranal and sorafenib (HCC+safranal+sorafenib) reduced reticular fibers' breakage and restored their morphology comparing to HCC group, showing more intact bundles of reticulin fibers, and smaller lesions compared to their counterparts in livers of animals treated with sorafenib alone (HCC+sorafenib).

Anti-Proliferative Effect of Safranal

As shown in the western blot results of FIG. 7, safranal inhibits proliferation of induced hepatic neoplasia. FIG. 7A is a western blot analysis of the proliferation-related protein (PCNA) on DEN-induced hepatic neoplasia in rats untreated (HCC group) or treated with sorafenib (HCC SB), safranal (HCC SF) individually or combined (HCC SF+SB). In FIG. 7B, each band intensity was quantified using ImageJ, normalized in relative to the total protein from the liver. Results are expressed as mean.+-.S.D for n=4 animals in each group. Significance was determined by one-way ANOVA followed by Tukey's post hoc analysis (P<0.05). The results showed that PCNA was significantly (P<0.05) increased in DEN induced livers comparing to controls, while treatment with safranal (P<0.05) and with both safranal and sorafenib (P<0.05) significantly downregulated PCNA.

Effect of Safranal on Cell Cycle Progression

To study the pathway responsible for safranal mediated cell cycle effect in DEN-induced rat liver neoplasia, the expression levels of cell cycle-related proteins were examined. Cdk1, cyclin B1, Cdc25B western blot results (FIG. 8) showed that they are significantly (P<0.05) increased in HCC animals as compared to control animals. Treatment in (HCC+safranal) and (HCC+safranal+sorafenib) groups significantly decreased their levels (P<0.05) comparing to HCC animals. Treatment with safranal (HCC+safranal) and the combination drug (HCC+safranal+sorafenib) showed a greater decrease than treatment with sorafenib alone (HCC+sorafenib) (FIG. 9). Without being bound to any particular theory, it is possible then that safranal may sensitize hepatic cells to sorafenib's effect by further decreasing the expression of cell cycle-related proteins in the co-treated group. These results suggest that safranal causes G2/M cell cycle arrest of drug-treated hepatic cells.

Effect of Safranal on Apoptosis

To study the pathway responsible for safranal mediated apoptosis in DEN-induced rat liver tumor cells, the expression levels of apoptosis-related proteins were examined in the western blot of FIG. 10. The results showed that safranal treatment significantly (P<0.05) increased the expression of the pro-apoptotic protein Bax and significantly (P<0.05) decreased the expression of the anti-apoptotic protein Bcl-2 compared to HCC groups. The Bax/Bcl-2 ratio favored the apoptotic effect of safranal (P<0.05) in DEN-induced rat liver tumors (FIG. 11).

To further investigate the apoptotic effect of safranal, western blot analysis showed that pro-caspase-9, pro-caspase-3, and PARP results confirmed caspase cascade activation and PARP cleavage, where the expression of pro-caspases-9 & 3 and whole PARP were significantly decreased compared to HCC group after treatments with safranal (P<0.05) and with both safranal+sorafenib (P<0.05) (FIG. 12). Interestingly, safranal seemed to help sorafenib-induced PARP cleavage in the animal group treated with both safranal and sorafenib.

Gene Expression Study

Out of whole data set of 32884 sequenced genes, 2400 genes were selected randomly to view an overall expression pattern among the different groups through hierarchical cluster analysis. FIG. 14 provides a heatmap of gene expression profiles for all the groups. Hierarchical cluster analysis represents the mean of the triplicate for each group. Raw data were centered and unit variance scaling was applied. Groups were clustered by maximum distance and complete linkage. Expression levels are colored red for high expression and grey for low expression. This analysis displayed visibly distinguishable patterns across the groups as it detached the experimental groups/cancer induced groups from the control PBS group as expected. Experimental groups (HCC+sorafenib) and (HCC+safranal+sorafenib) clustered closely together leaving HCC group and (HCC+safranal) nearby. Through the aid of color code, it is quite strikingly the difference of gene pattern of (HCC+safranal) to other groups.

Definitions

As used in this description and the accompanying claims, the following terms shall have the meanings indicated, unless the context otherwise requires:

As used herein, "treatment" is understood to refer to the administration of a drug or drugs to a patient suffering from cancer.

As used herein, the term "therapeutically effective amount" means that amount of a drug or pharmaceutical agent that will elicit the biological or medical response of a tissue, system, animal or human that is being sought, for instance, by a researcher or clinician. Furthermore, the term "therapeutically effective amount" means any amount which, as compared to a corresponding subject who has not received such amount, results in improved treatment, healing, prevention, or amelioration of a disease, disorder, or side effect, or a decrease in the rate of advancement of a disease or disorder. The term also includes within its scope amounts effective to enhance normal physiological function.

As used herein for describing ranges, e.g., of ratios, doses, times, and the like, the terms "about" embraces variations that are within the relevant margin of error, essentially the same (e.g., within an art-accepted confidence interval such as 95% for phenomena that follow a normal or Gaussian distribution), or otherwise does not materially change the effect of the thing being quantified.

As used herein, the term "pro-drug" defined as an inactive form of the drug that is metabolized after administration to a subject to produce the drug having a biological effect.