Genistein enhances the efficacy of cabazitaxel chemotherapy in metastatic castration-resistant prostate cancer cells

Eprinomectin: a derivative of ivermectin suppresses growth and metastatic phenotypes of prostate cancer cells by targeting the β-catenin signaling pathway

PURPOSE

Prostate cancer (PCa) is the second leading cause of cancer death among men in the USA. The emergence of resistance to androgen deprivation therapy gives rise to metastatic castration-resistant prostate cancer. Eprinomectin (EP) is a member of a family of drugs called avermectins with parasiticide and anticancer properties. The pupose of this study was to evaluate the anticancer effects of EP against metastatic PCa using cellular models.  METHODS: In this study, we have investigated the effect of EP's anticancer properties and delineated the underlying mechanisms in the DU145 cellular model using several assays such as cell viability assay, colony formation assay, wound-healing assay, immunofluorescence, apoptosis assay, cell cycle analysis, and immunoblotting.

RESULTS

Our results indicate that EP significantly inhibits the cell viability, colony formation, and migration capacities of DU145 cells. EP induces cell cycle arrest at the G0/G1 phase, apoptosis via the activation of different caspases, and autophagy through the increase in the generation of reactive oxygen species and endoplasmic reticulum stress. In addition, EP downregulates the expression of cancer stem cell markers and mediates the translocation of β-catenin from the nucleus to the cytoplasm, indicating its role in inhibiting downstream target genes such as c-Myc and cyclin D1.

CONCLUSION

Our study shows that EP has tremendous potential to target metastatic PCa cells and provides new avenues for therapeutic approaches for advanced PCa.

Chemopreventive Potential of Dietary Nanonutraceuticals for Prostate Cancer: An Extensive Review

There are more than two hundred fifty different types of cancers, that are diagnosed around the world. Prostate cancer is one of the suspicious type of cancer spreading very fast around the world, it is reported that in 2018, 29430 patients died of prostate cancer in the United State of America (USA), and hence it is expected that one out of nine men diagnosed with this severe disease during their lives. Medical science has identified cancer at several stages and indicated genes mutations involved in the cancer cell progressions. Genetic implications have been studied extensively in cancer cell growth. So most efficacious drug for prostate cancer is highly required just like other severe diseases for men. So nutraceutical companies are playing major role to manage cancer disease by the recommendation of best natural products around the world, most of these natural products are isolated from plant and mushrooms because they contain several chemoprotective agents, which could reduce the chances of development of cancer and protect the cells for further progression. Some nutraceutical supplements might activate the cytotoxic chemotherapeutic effects by the mechanism of cell cycle arrest, cell differentiation procedures and changes in the redox states, but in other, it also elevate the levels of effectiveness of chemotherapeutic mechanism and in results, cancer cell becomes less reactive to chemotherapy. In this review, we have highlighted the prostate cancer and importance of nutraceuticals for the control and management of prostate cancer, and the significance of nutraceuticals to cancer patients during chemotherapy.

A Mini-Review of Flavone Isomers Apigenin and Genistein in Prostate Cancer Treatment

The initial responses to standard chemotherapies among prostate cancer (PCa) patients are usually significant, while most of them will finally develop drug resistance, rendering them with limited therapies. To discover new regimens for the treatment of PCa including resistant PCa, natural products, the richest source of bioactive compounds, can serve as a library for screening and identifying promising candidates, and flavones such as apigenin and genistein have been used in lab and clinical trials for treating PCa over decades. In this mini-review, we take a look into the progress of apigenin and genistein, which are isomers, in treating PCa in the past decade. While possessing very similar structure, these two isomers can both target the same signaling pathways; they also are found to work differently in PCa cells. Given that more combinations are being developed and tested, genistein appears to be the more promising option to be approved. The anticancer efficacies of these two flavones can be confirmed by in-vitro and in-vivo studies, and their applications remain to be validated in clinical trials. Information gained in this work may provide important information for new drug development and the potential application of apigenin and genistein in treating PCa.

Chitosan as possible inhibitory agents and delivery systems in leukemia

Leukemia is a lethal cancer in which white blood cells undergo proliferation and immature white blood cells are seen in the bloodstream. Without diagnosis and management in early stages, this type of cancer can be fatal. Changes in protooncogenic genes and microRNA genes are the most important factors involved in development of leukemia. At present, leukemia risk factors are not accurately identified, but some studies have pointed out factors that predispose to leukemia. Studies show that in the absence of genetic risk factors, leukemia can be prevented by reducing the exposure to risk factors of leukemia, including smoking, exposure to benzene compounds and high-dose radioactive or ionizing radiation. One of the most important treatments for leukemia is chemotherapy which has devastating side effects. Chemotherapy and medications used during treatment do not have a specific effect and destroy healthy cells besides leukemia cells. Despite the suppressing effect of chemotherapy against leukemia, patients undergoing chemotherapy have poor quality of life. So today, researchers are focusing on finding more safe and effective natural compounds and treatments for cancer, especially leukemia. Chitosan is a valuable natural compound that is biocompatible and non-toxic to healthy cells. Anticancer, antibacterial, antifungal and antioxidant effects are examples of chitosan biopolymer properties. The US Food and Drug Administration has approved the use of this compound in medical treatments and the pharmaceutical industry. In this article, we take a look at the latest advances in the use of chitosan in the treatment and improvement of leukemia.

Genistein: An Integrative Overview of Its Mode of Action, Pharmacological Properties, and Health Benefits

Genistein is an isoflavone first isolated from the brooming plant Dyer's Genista tinctoria L. and is widely distributed in the Fabaceae family. As an isoflavone, mammalian genistein exerts estrogen-like functions. Several biological effects of genistein have been reported in preclinical studies, such as the antioxidant, anti-inflammatory, antibacterial, and antiviral activities, the effects of angiogenesis and estrogen, and the pharmacological activities on diabetes and lipid metabolism. The purpose of this review is to provide up-to-date evidence of preclinical pharmacological activities with mechanisms of action, bioavailability, and clinical evidence of genistein. The literature was researched using the most important keyword "genistein" from the PubMed, Science, and Google Scholar databases, and the taxonomy was validated using The Plant List. Data were also collected from specialized books and other online resources. The main positive effects of genistein refer to the protection against cardiovascular diseases and to the decrease of the incidence of some types of cancer, especially breast cancer. Although the mechanism of protection against cancer involves several aspects of genistein metabolism, the researchers attribute this effect to the similarity between the structure of soy genistein and that of estrogen. This structural similarity allows genistein to displace estrogen from cellular receptors, thus blocking their hormonal activity. The pharmacological activities resulting from the experimental studies of this review support the traditional uses of genistein, but in the future, further investigations are needed on the efficacy, safety, and use of nanotechnologies to increase bioavailability and therapeutic efficacy.

PGM5-AS1 impairs miR-587-mediated GDF10 inhibition and abrogates progression of prostate cancer

Background

Prostate cancer (PCa) is a leading cause of cancer-related death in males. Aberrant expression of long non-coding RNAs (lncRNAs) has been implicated in various human malignancies, including PCa. This study aims to clarify the inhibitory role of human PGM5 antisense RNA 1 (PGM5-AS1) in the proliferation and apoptosis of PCa cells.

Methods

The regulatory network of PGM5-AS1/microRNA-587 (miR-587)/growth and differentiation factor 10 (GDF10) axis was examined by dual-luciferase reporter gene assay, RNA-binding protein immunoprecipitation, and RNA pull down assay. We manipulated the expression of PGM5-AS1, miR-587 and GDF10 by transducing expression vectors, mimic, inhibitor, or short hairpin RNA into PCa cells, thus establishing their functions in cell proliferation and apoptosis. Additionally, we measured the tumorigenicity of PCa cells xenografted in nude mice.

Results

PGM5-AS1 is expressed at low levels in PCa cell lines. Forced overexpression of PGM5-AS1 restricted proliferation and facilitated apoptosis of PCa cells, manifesting in suppressed xenograft tumor growth in nude mice. Notably, PGM5-AS1 competitively bound to miR-587, which directly targets GDF10. We further validated that the anti-cancer role of PGM5-AS1 in PCa cells was achieved by binding to miR-587 to promote the expression of GDF10.

Conclusion

PGM5-AS1 upregulates GDF10 gene expression by competitively binding to miR-587, thus inhibiting proliferation and accelerating apoptosis of PCa cells.

Eprinomectin, a novel semi-synthetic macrocylic lactone is cytotoxic to PC3 metastatic prostate cancer cells via inducing apoptosis

Prostate Cancer (PCa) is the second most common cancer among men in United States after skin cancer. Conventional chemotherapeutic drugs available for PCa treatment are limited due to toxicity and resistance issues. Therefore, there is an urgent need to develop more effective treatment for advanced PCa. In this current study, we focused on evaluating the anti-cancer efficacy of Eprinomectin (EP), a novel avermectin analog against PC3 metastatic PCa cells. EP displayed robust inhibition of cell viability of PC3 cells in addition to suppressing the colony formation and wound healing capabilities. Our study showed that EP targets PC3 cells via inducing ROS and apoptosis activation. EP treatment enforces cell cycle arrest at G0/G1 phase via targeting cyclin-dependent kinase 4 (CDK4) and subsequent induction of apoptosis in PC3 cells. At the molecular level, EP effectively inhibited the expression of various cancer stem cell markers such as ALDH1, Sox-2, Nanog, Oct3/4 and CD44. Interestingly, EP also inhibited the activity of alkaline phosphatase, a maker of pluripotent stem cells. Of note, EP treatment resulted in the translocation of β-catenin from the nucleus to the cytoplasm indicating that EP antagonizes Wnt/β-catenin signaling pathway. Western blotting analysis revealed that EP downregulated the expression of key cell cycle markers such as cyclin D1, cyclin D3, CDK4, and c-Myc. In addition, EP inhibited the anti-apoptotic markers such as Mcl-1, XIAP, c-IAP1 and survivin in PC3 cells. On the other hand, EP treatment resulted in the activation of pH2A.X, Bad, caspase-9, caspase-3 and cleavage of PARP1. Taken together, our data suggests that EP is a potential agent to treat advanced PCa cells via modulating apoptosis signaling.

Synthesizing efficacious genistein in conjugation with superparamagnetic Fe3O4 decorated with bio-compatible carboxymethylated chitosan against acute leukemia lymphoma

Background

Genistein (C₁₅H₁₀O₅) is a soy isoflavone with anti-cancer properties such as inhibition of cell growth, proliferation and tumor invasion, but effective dosage against hematopoietic malignant cells was not in non-toxic range. This property cause to impede its usage as chemotherapeutic agent. Therefore, this hypothesis raised that synthesizing biocompatible nanoparticle could assist to prevail this struggle.

Methods

Genistein covalently attached on Fe₃O₄ nanoparticles decorated with carboxymethylated chitosan to fabricate Fe₃O₄-CMC-genistein in alkaline circumstance. This obtained nanoparticles were evaluated by TEM, DLS, FTIR, XRD and VSM and its anti-cancer effect by growth rate and MTT assays as well as flow cytometer on ALL cancer cell lines.

Results

Different evaluations indicated that the drug delivery vehicle had a mean diameter size around 12ƞm with well bounded components. This system presented high degree of magnetization and superparamagnetic properties as well as good water solubility. In comparison with pure genistein, significant growth inhibition on hematopoietic cancer cells in lower dose of genistein nano-conjugated onto Fe₃O₄-CMC. It increased long lasting effect of genistein in cancer cells also.

Conclusion

This delivery system for genistein could be remarkably promised and futuristic as biocompatible chemotherapeutic agent against hematopoietic malignant cells.

Neferine treatment enhances the TRAIL‑induced apoptosis of human prostate cancer cells via autophagic flux and the JNK pathway

Prostate cancer (PCa) is a common type of cancer among males, with a relatively high mortality rate. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a member of the tumor necrosis factor (TNF) family, initiates the apoptosis of certain cancer cells. Neferine, a primary ingredient of bisbenzylisoquinoline alkaloids, has various antitumor activities. The present study examined the effects of neferine treatment on human PCa cells. Human prostate cancer (DU145) cells were treated with neferine for 18 h, and subsequently treated with TRAIL for 2 h. Combined treatment with neferine and TRAIL significantly decreased cell viability compared to treatment with TRAIL alone. Furthermore, neferine treatment decreased the expression of p62 and increased LC3B-II expression, as assessed by western blot analysis and immunocytochemistry. It was alsp demonstrated that neferine and TRAIL act synergistically to trigger autophagy in PCa cells, as revealed by autophagosome formation, LC3B-II accumulation demonstrated by transmission electron microscopy (TEM) analysis and phosphorylated c-Jun N-terminal kinase (p-JNK) upregulation. When the autophagic flux was attenuated by the inhibitor, chloroquine, or by genetically modified ATG5 siRNA, the enhancement of TRAIL-induced autophagy by neferine-induced was also attenuated. Furthermore, treatment with the JNK inhibitor, SP600125, distinctly increased the viability of the cells treated with neferine and TRAIL. On the whole, the findings of the present study demonstrate that neferine treatment effectively promotes TRAIL-mediated cell death and this effect likely occurs via the autophagic flux and the JNK pathway.

A Novel Small Molecule Inhibits Tumor Growth and Synergizes Effects of Enzalutamide on Prostate Cancer

Prostate cancer (PCa) is the second leading cause of cancer-related death for men in the United States. Approximately 35% of PCa recurs and is often transformed to castration-resistant prostate cancer (CRPCa), the most deadly and aggressive form of PCa. However, the CRPCa standard-of-care treatment (enzalutamide with abiraterone) usually has limited efficacy. Herein, we report a novel molecule (PAWI-2) that inhibits cellular proliferation of androgen-sensitive and androgen-insensitive cells (LNCaP and PC-3, respectively). In vivo studies in a PC-3 xenograft model showed that PAWI-2 (20 mg/kg per day i.p., 21 days) inhibited tumor growth by 49% compared with vehicle-treated mice. PAWI-2 synergized currently clinically used enzalutamide in in vitro inhibition of PCa cell viability and resensitized inhibition of in vivo PC-3 tumor growth. Compared with vehicle-treated mice, PC-3 xenograft studies also showed that PAWI-2 (20 mg/kg per day i.p., 21 days) and enzalutamide (5 mg/kg per day i.p., 21 days) inhibited tumor growth by 63%. Synergism was mainly controlled by the imbalance of prosurvival factors (e.g., Bcl-2, Bcl-xL, Mcl-1) and antisurvival factors (e.g., Bax, Bak) induced by affecting mitochondrial membrane potential/mitochondria dynamics. Thus, PAWI-2 utilizes a distinct mechanism of action to inhibit PCa growth independently of androgen receptor signaling and overcomes enzalutamide-resistant CRPCa. SIGNIFICANCE STATEMENT: Castration-resistant prostate cancer (CRPCa) is the most aggressive human prostate cancer (PCa) but standard chemotherapies for CRPCa are largely ineffective. PAWI-2 potently inhibits PCa proliferation in vitro and in vivo regardless of androgen receptor status and uses a distinct mechanism of action. PAWI-2 has greater utility in treating CRPCa than standard-of-care therapy. PAWI-2 possesses promising therapeutic potency in low-dose combination therapy with a clinically used drug (e.g., enzalutamide). This study describes a new approach to address the overarching challenge in clinical treatment of CRPCa.

Restraining the Proliferation of Acute Lymphoblastic Leukemia Cells by Genistein through Up-regulation of B-cell Translocation Gene-3 at Transcription Level

Background:

Acute lymphoblastic leukemia (ALL) is a highly prevalent pediatric cancer accounting for approximately 78% of leukemia cases in patients younger than 15 years old. Different studies have demonstrated that B-cell translocation gene 3 (BTG3) plays a suppressive role in the progress of different cancers. Genistein is considered a natural and biocompatible compound and a new anti-cancer agent. In this study, we evaluate the effect of genistein on BTG3 expression and proliferation of ALL cancer cells.

Materials and Methods:

ALL cell lines (MOLT4, MOLT17, and JURKAT) were cultured in standard conditions. Cytotoxicity of genistein was detected using MTT assay. The cells were treated with different concentrations of genistein (10, 25, 40, and 55μM) for 24, 48, and 72 hours, and then cell viability and growth rate were measured. The quantitative real-time polymerase chain reaction was applied to investigate the effect of genistein on BTG3 expression.

Results:

The percentage of vital cells treated with genistein significantly decreased compared to the non-treated cells, showed an inverse relationship with an increasing genistein concentration. The present study suggests a dose of 40μM for genistein as a potent anticancer effect. Genistein could elevate BTG3 for 1.7 folds in MOLT4 and JURKAT and 2.7 folds in MOLT17 cell lines at transcription level conveged with 60 to 90% reduction in the proliferation rate of cancer cells.

Conclusion:

Up-regulation of BTG3 as a tumor suppressor gene can be induced by genistein. It seems that BTG3 reactivation can be introduced as another mechanism of anti-proliferative effect of genistein and could be considered as a retardant agent candidate against hematopoietic malignancy.

Lack of combination effects of soy isoflavones and taxane chemotherapy of castration-resistant prostate cancer

BACKGROUND

Patients with cancer, including prostate cancer, often use dietary supplements, such as soy or isoflavones, before, during, or after therapy. There is little information about possible interactions between supplements and cancer chemotherapy. There are some reports suggesting enhancement by genistein of taxane chemotherapy for castrate-resistant prostate cancer (CRPC).

METHODS

We investigated whether physiologically attainable concentrations of soy isoflavones (≤10 μM) interact with taxanes on growth inhibition of CRPC cells in vitro and in vivo in nude mice exposed via the diet, on microtubule disassembly in vitro, and on P-glycoprotein-mediated drug efflux in 22Rv1 cells and CYP3A4 activity in microsomes.

RESULTS

Genistein, daidzein, and equol did not affect growth of VCaP, 22Rv1, C4-2, and PC-3 CRPC cells or growth inhibition of these cells by docetaxel and cabazitaxel. These isoflavones did not inhibit microtubule disassembly in vitro or inhibit the microtubule effects of taxanes and genistein did not bind substantially to microtubules. Genistein considerably inhibited P-glycoprotein-mediated drug efflux in 22Rv1 cells and CYP3A4 activity in microsomes. However, dietary supplementation with genistein at 250 and 500 ppm did not affect the tumor growth inhibiting effect of docetaxel on 22Rv1 cells xenografted in nude mice.

CONCLUSIONS

Our results with relevant cell models and clinically achievable concentrations of soy isoflavones do not support the notion that genistein or other soy isoflavones can enhance the effects of taxane chemotherapy in CRPC cell and xenograft models. Yet, the inhibitory effects of genistein on drug efflux in 22Rv1 cells and on microsomal CYP3A4 activity raise the possibility that genistein can affect taxane effects on CRPC cells in other circumstances than those we studied, which merits further research.

Fisetin Enhances Chemotherapeutic Effect of Cabazitaxel against Human Prostate Cancer Cells

Although treatment of prostate cancer has improved over the past several years, taxanes, such as cabazitaxel, remain the only form of effective chemotherapy that improves survival in patients with metastatic castration-resistant prostate cancer. However, the effectiveness of this class of drugs has been associated with various side effects and drug resistance. We previously reported that fisetin, a hydroxyflavone, is a microtubule-stabilizing agent and inhibits prostate cancer cell proliferation, migration, and invasion and suggested its use as an adjuvant for treatment of prostate and other cancer types. In this study, we investigated the effect of fisetin in combination with cabazitaxel with the objective to achieve maximum therapeutic benefit, reduce dose and toxicity, and minimize or delay the induction of drug resistance and metastasis. Our data show for the first time that a combination of fisetin (20 μmol/L) enhances cabazitaxel (5 nmol/L) and synergistically reduces 22Rν1, PC-3M-luc-6, and C4-2 cell viability and metastatic properties with minimal adverse effects on normal prostate epithelial cells. In addition, the combination of fisetin with cabazitaxel was associated with inhibition of proliferation and enhancement of apoptosis. Furthermore, combination treatment resulted in the inhibition of tumor growth, invasion, and metastasis when assessed in two in vivo xenograft mouse models. These results provide evidence that fisetin may have therapeutic benefit for patients with advanced prostate cancer through enhancing the efficacy of cabazitaxel under both androgen-dependent and androgen-independent conditions. This study underscores the benefit of the combination of fisetin with cabazitaxel for the treatment of advanced and resistant prostate cancer and possibly other cancer types. Mol Cancer Ther; 15(12); 2863-74. ©2016 AACR.

Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand-Induced Apoptosis in Prostate Cancer Cells after Treatment with Xanthohumol-A Natural Compound Present in Humulus lupulus L

TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) is an endogenous ligand, which plays role in immune surveillance and anti-tumor immunity. It has ability to selectively kill tumor cells showing no toxicity to normal cells. We tested the apoptotic and cytotoxic activities of xanthohumol, a prenylated chalcone found in Humulus lupulus on androgen-sensitive human prostate adenocarcinoma cells (LNCaP) in combination with TRAIL. Cytotoxicity was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazolium reduction assay (MTT) and lactate dehydrogenase assay (LDH). The expression of death receptors (DR4/TRAIL-R1 and DR5/TRAIL-R2) and apoptosis were detected using flow cytometry. We examined mitochondrial membrane potential (ΔΨm) by DePsipher reagent using fluorescence microscopy. The intracellular expression of proteins was evaluated by Western blotting. Our study showed that xanthohumol enhanced cytotoxic and apoptotic effects of TRAIL. The tested compounds activated caspases-3, -8, -9, Bid, and increased the expression of Bax. They also decreased expression of Bcl-xL and decreased mitochondrial membrane potential, while the expression of death receptors was not changed. The findings suggest that xanthohumol is a compound of potential use in chemoprevention of prostate cancer due to its sensitization of cancer cells to TRAIL-mediated apoptosis.

Forced LIGHT expression in prostate tumors overcomes Treg mediated immunosuppression and synergizes with a prostate tumor therapeutic vaccine by recruiting effector T lymphocytes

BACKGROUND

LIGHT, a ligand for lymphotoxin-β receptor (LTβR) and herpes virus entry mediator, is predominantly expressed on activated immune cells and LTβR signaling leads to the recruitment of lymphocytes. The interaction between LIGHT and LTβR has been previously shown to activate immune cells and result in tumor regression in a virally-induced tumor model, but the role of LIGHT in tumor immunosuppression or in a prostate cancer setting, where self antigens exist, has not been explored. We hypothesized that forced expression of LIGHT in prostate tumors would shift the pattern of immune cell infiltration toward an anti-tumoral milieu, would inhibit T regulatory cells (Tregs) and would induce prostate cancer tumor associated antigen (TAA) specific T cells that would eradicate tumors.

METHODS

Real Time PCR was used to evaluate expression of forced LIGHT and other immunoregulatory genes in prostate tumors samples. For in vivo studies, adenovirus encoding murine LIGHT was injected intratumorally into TRAMP-C2 prostate cancer cell tumor bearing mice. Chemokine and cytokine concentrations were determined by multiplex ELISA. Flow cytometry was used to phenotype tumor infiltrating lymphocytes and expression of LIGHT on the tumor cell surface. Tumor-specific lymphocytes were quantified via ELISpot assay. Treg induction and Treg suppression assays determined Treg functionality after LIGHT treatment.

RESULTS

LIGHT in combination with a therapeutic vaccine, PSCA TriVax, reduced tumor burden. LIGHT expression peaked within 48 hr of infection, recruited effector T cells that recognized mouse prostate stem cell antigen (PSCA) into the tumor microenvironment, and inhibited infiltration of Tregs. Tregs isolated from tumor draining lymph nodes had impaired suppressive capability after LIGHT treatment.

CONCLUSION

Forced LIGHT treatment combined with PSCA TriVax therapeutic vaccination delays prostate cancer progression in mice by recruiting effector T lymphocytes to the tumor and inhibiting Treg mediated immunosuppression. Prostate 75:280-291, 2015. © 2014 Wiley Periodicals, Inc.

Nutrition, dietary interventions and prostate cancer: the latest evidence

Prostate cancer (PCa) remains a leading cause of mortality in US men and the prevalence continues to rise world-wide especially in countries where men consume a 'Western-style' diet. Epidemiologic, preclinical and clinical studies suggest a potential role for dietary intake on the incidence and progression of PCa. 'This minireview provides an overview of recent published literature with regard to nutrients, dietary factors, dietary patterns and PCa incidence and progression. Low carbohydrates intake, soy protein, omega-3 (w-3) fat, green teas, tomatoes and tomato products and zyflamend showed promise in reducing PCa risk or progression. A higher saturated fat intake and a higher β-carotene status may increase risk. A 'U' shape relationship may exist between folate, vitamin C, vitamin D and calcium with PCa risk. Despite the inconsistent and inconclusive findings, the potential for a role of dietary intake for the prevention and treatment of PCa is promising. The combination of all the beneficial factors for PCa risk reduction in a healthy dietary pattern may be the best dietary advice. This pattern includes rich fruits and vegetables, reduced refined carbohydrates, total and saturated fats, and reduced cooked meats. Further carefully designed prospective trials are warranted.

Chemopreventive and chemotherapeutic effects of genistein, a soy isoflavone, upon cancer development and progression in preclinical animal models

Genistein is one of isoflavones mostly derived in a leguminous plant. It is well known as one of phytoestrogens that have structures similar to the principal mammalian estrogen. It has diverse biological functions including chemopreventive properties against cancers. Anticancer efficacies of genistein have been related with the epidemiological observations indicating that the incidence of some cancers is much lower in Asia, where diets are rich in soyfoods, than Western countries. This review deals with in vivo anticancer activities of genistein identified in animal studies being divided into its effects on carcinogenesis and cancer progression. Because animal studies have advantages in designing the experiments to suit the goals, they imply diverse information on the anticancer activity of genistein. The in vivo animal studies have adopted the specific animal models according to a developmental stage of cancer to prove the anticancer efficacies of genistein against diverse types of cancer. The numerous previous studies insist that genistein effectively inhibits carcinogenesis in the DMBA-induced animal cancer models by reducing the incidence of adenocarcinoma and cancer progression in the transgenic and xenograft animal models by suppressing the tumor growth and metastatic transition. Although the protective effect of genistein against cancer has been controversial, genistein may be a candidate for chemoprevention of carcinogenesis and cancer progression and may deserve to be the central compound supporting the epidemiological evidence.

Knockdown of cancerous inhibitor of protein phosphatase 2A may sensitize metastatic castration-resistant prostate cancer cells to cabazitaxel chemotherapy

Cancerous inhibitor of protein phosphatase 2A (CIP2A) is a recently identified human oncoprotein that can stabilize some proteins by inhibiting degradation mediated by protein phosphatase 2A (PP2A), and its level in cancer is associated with resistance to chemotherapy. However, whether CIP2A could increase chemoresistance of prostate cancer (PCa) cells to chemotherapeutic agent cabazitaxel remains unclear. To determine whether CIP2A serves as a potential therapeutic target of human PCa, we utilized small interference RNA (siRNA) to knock down CIP2A expression in human PCa cells and analyzed their phenotypic changes. The data demonstrated that CIP2A was significantly elevated in mCRPC cell lines C4-2 and ARCaP(M) at both the mRNA and protein levels. CIP2A silencing led to decreased proliferation and enhanced chemosensitivity and apoptosis to cabazitaxel in human PCa cells, as well as reduced Akt phosphorylation. Our data suggesting critical roles of CIP2A in PCa cells chemoresistance to cabazitaxel and raising the possibility of CIP2A inhibition as a promising approach for chemosensitization of metastatic castration-resistant prostate cancer (mCRPC).