Cancer is a condition characterized by remarkably enhanced rates of cell proliferation paired with evasion of cell death. These deregulated cellular processes take place following genetic mutations leading to the activation of oncogenes, the loss of tumor suppressor genes, and the disruption of key signaling pathways that control and promote homeostasis. Plant extracts and plant-derived compounds have historically been utilized as medicinal remedies in different cultures due to their anti-inflammatory, antioxidant, and antimicrobial properties. Many chemotherapeutic agents used in the treatment of cancer are derived from plants, and the scientific interest in discovering plant-derived chemicals with anticancer potential continues today. Curcumin, a turmeric-derived polyphenol, has been reported to possess antiproliferative and proapoptotic properties. In the present review, we summarize all the in vitro and in vivo studies examining the effects of curcumin in prostate cancer.

Cancer is a disease associated with extreme human suffering, a huge economic cost to health systems, and is the second leading cause of death worldwide. Regular physical activity is associated with many health benefits, including reduced cancer risk. In the past two decades, exercising/contracting skeletal muscles have been found to secrete a wide range of biologically active proteins, named myokines. Myokines are delivered, via the circulation, to different cells/tissues, bind to their specific receptors and initiate signaling cascades mediating the health benefits of exercise. The present review summarizes the existing evidence of the role of the myokine irisin in cancer. In vitro studies have shown that the treatment of various cancer cells with irisin resulted in the inhibition of cell proliferation, survival, migration/ invasion and induced apoptosis by affecting key proliferative and antiapoptotic signaling pathways. However, the effects of irisin in humans remains unclear. Although the majority of the existing studies have found reduced serum irisin levels in cancer patients, a few studies have shown the opposite. Similarly, the majority of studies have found increased levels of irisin in cancer tissues, with a few studies showing the opposite trend. Clearly, further investigations are required to determine the exact role of irisin in cancer.

Breast cancer is the most commonly diagnosed cancer in women. Triple-negative (TN) breast cancer lacks expression of estrogen receptor (ER), progesterone receptor (PR) as well as the expression and/or gene amplification of human epidermal growth factor receptor 2 (HER2). TN breast cancer is aggressive and does not respond to hormone therapy, therefore new treatments are urgently needed. Plant-derived chemicals have contributed to the establishment of chemotherapy agents. In previous studies, rosemary extract (RE) has been found to reduce cell proliferation and increase apoptosis in some cancer cell lines. However, there are very few studies examining the effects of RE in TN breast cancer. In the present study, we examined the effects of RE on TN MDA-MB-231 breast cancer cell proliferation, survival/apoptosis, Akt, and mTOR signaling. RE inhibited MDA-MB-231 cell proliferation and survival in a dose-dependent manner. Furthermore, RE inhibited the phosphorylation/activation of Akt and mTOR and enhanced the cleavage of PARP, a marker of apoptosis. Our findings indicate that RE has potent anticancer properties against TN breast cancer and modulates key signaling molecules involved in cell proliferation and survival.

Prostate cancer is the most commonly diagnosed type of cancer in North American men and is typically classified as either androgen receptor positive or negative depending on the expression of the androgen receptor (AR). AR positive prostate cancer can be treated with hormone therapy while AR negative prostate cancer is aggressive and does not respond to hormone therapy. It has been previously reported that rosemary extract (RE) has antioxidant, anti-inflammatory and anti-cancer properties. In the present study, we found that treatment of the androgen-insensitive PC-3 prostate cancer cells with RE resulted in a significant inhibition of proliferation, survival, migration, Akt, and mTOR signaling. In addition, treatment of the androgen-sensitive 22RV1 prostate cancer cells with RE resulted in a significant inhibition of proliferation and survival while RE had no effect on normal prostate epithelial PNT1A cells. These findings suggest that RE has potent effects against prostate cancer and warrants further investigation.

Prostate cancer is the most commonly diagnosed cancer in men. Despite many advances in diagnosis and treatment, prostate cancer is the second‐leading cause of cancer related death amongst men in North America and therefore there is an urgent need to find novel chemicals that can be used effectively towards the treatment of prostate cancer patients. Prostate cancers are typically characterized by the expression of androgen receptor (AR) and prostate‐specific antigen (PSA). Prostate cancers that are AR positive can be treated with hormonal therapy, however those which are AR negative are more aggressive and do not respond to hormone therapy, thus this subtype of prostate cancer requires targeted treatments. Many chemotherapeutic drugs have been discovered by screening natural products from plants. Polyphenols derived from the plant rosemary, have been found to have antioxidant and anti‐inflammatory effects and are proposed to have anticancer activity. In previous studies, rosemary extract (RE) has been found to reduce cell proliferation, viability, survival, and increase apoptosis in various cancer cell lines. However, there is very limited evidence examining RE's effects in androgen receptor negative prostate cancer cells. In the present study, we examine the effects of rosemary extract on PC‐3 prostate cancer cell proliferation, survival, migration and apoptosis. RE significantly inhibited PC‐3 cell proliferation and survival in a dose dependent manner. Furthermore, RE reduced cell migration and enhanced the cleavage of PARP, a marker of apoptosis. Our findings indicate that RE may have potent anti‐cancer properties against AR negative prostate cancer and supports the need for further investigation into its role in modulating key signaling pathways involved in cell proliferation, survival, and migration. Support or Funding Information Supported by the Prostate Cancer Fight Foundation. This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .