p53 has an essential role in suppressing the carcinogenesis process by inducing cell cycle arrest/apoptosis/senescence. Mortalin/GRP75 is a member of the Hsp70 protein family that binds to p53 causing its sequestration in the cell cytoplasm. Hence, p53 cannot translocate to the nucleus to execute its canonical tumour suppression function as a transcription factor. Abrogation of mortalin-p53 interaction and subsequent reactivation of p53’s tumour suppression function has been anticipated as a possible approach in developing a novel cancer therapeutic drug candidate. A chemical library was screened in a high-content screening system to identify potential mortalin-p53 interaction disruptors. By four rounds of visual assays for mortalin and p53, we identified a novel synthetic small-molecule triazole derivative (4-[(1E)-2-(2-phenylindol-3-yl)-1-azavinyl]-1,2,4-triazole, henceforth named MortaparibPlus). Its activities were validated using multiple bioinformatics and experimental approaches in colorectal cancer cells possessing either wild-type (HCT116) or mutant (DLD-1) p53. Bioinformatics and computational analyses predicted the ability of MortaparibPlus to competitively prevent the interaction of mortalin with p53 as it interacted with the p53 binding site of mortalin. Immunoprecipitation analyses demonstrated the abrogation of mortalin-p53 complex formation in MortaparibPlus-treated cells that showed growth arrest and apoptosis mediated by activation of p21WAF1, or BAX and PUMA signalling, respectively. Furthermore, we demonstrate that MortaparibPlus-induced cytotoxicity to cancer cells is mediated by multiple mechanisms that included the inhibition of PARP1, up-regulation of p73, and also the down-regulation of mortalin and CARF proteins that play critical roles in carcinogenesis. MortaparibPlus is a novel multimodal candidate anticancer drug that warrants further experimental and clinical attention.

Fucoxanthin is commonly found in marine organisms; however, to date, it has been one of the scarcely explored natural compounds. We investigated its activities in human cancer cell culture-based viability, migration, and molecular assays, and found that it possesses strong anticancer and anti-metastatic activities that work irrespective of the p53 status of cancer cells. In our experiments, fucoxanthin caused the transcriptional suppression of mortalin. Cell phenotype-driven molecular analyses on control and treated cells demonstrated that fucoxanthin caused a decrease in hallmark proteins associated with cell proliferation, survival, and the metastatic spread of cancer cells at doses that were relatively safe to the normal cells. The data suggested that the cancer therapy regimen may benefit from the recruitment of fucoxanthin; hence, it warrants further attention for basic mechanistic studies as well as drug development.

We screened some phytochemicals for cytotoxic activity to human cancer cells and identified Soyasapogenol-A (Snol-A) as a potent candidate anti-cancer compound. Interestingly, Soyasapogenin-I (Snin-I) was ineffective. Viability assays endorsed toxicity of Snol-A to a wide variety of cancer cells. Of note, wild type p53 deficient cancer cells (SKOV-3 and Saos-2) also showed potent growth inhibitory effect. Molecular analyses demonstrated that it targets CARF yielding transcriptional upregulation of p21 WAF1 (an inhibitor of cyclin-dependent kinases) and downregulation of its effector proteins, CDK2, CDK-4, Cyclin A and Cyclin D1. Targeting of CARF by Snol-A also caused (i) downregulation of pATR-Chk1 signaling leading to caspase-mediated apoptosis and (ii) inactivation of β-catenin/Vimentin/hnRNPKmediated EMT signaling resulting in decrease in migration and invasion of cancer cells. In in vivo assays, Snol-A caused suppression of tumor growth in subcutaneous xenograft model and inhibited lung metastasis in tail vein injection model. Taken together, we demonstrate that Snol-A is a natural inhibitor of CARF and may be recruited as a potent anti-tumor and anti-metastasis compound for treatment of p53-deficient aggressive malignancies. Cancer chemotherapy has made a remarkable progress in last two decades. However, conventional chemotherapeutic drugs are known to produce serious health issues, by affecting the normal body functions, and QOL of patients during and after the treatment 1. These adverse side-effects along with the emerging drug resistance 2 , have underlined a need of safe and effective alternatives for cancer treatment 2. Natural compounds, due to their easy availability, safety, and economic aspects have recently got much attention of researchers. Anticancer properties of several natural compounds have been demonstrated and their mechanism(s) of action against malignant disease are beginning to be revealed 3-7. Triterpenoids include a diverse group of triterpenes with more than 100 distinct skeletons 8. Ursolic acid, oleanolic acid, saponins and betulinic acid are among the well-known triterpenes and have been shown to possess a wide variety of biological activities such as anti-inflammatory 9 , anti-allergic 10 , cardio protective 11 , anti-diabetic 12 , metabolic regulation activities 13 and anti-cancer 14,15. Soybean has been a preferred source of protein in dietary regime worldwide 16. Soy-based food alternatives have attained a larger recognition, owing to their health benefits as functional food 17. In Asian sub-continent, especially Japan, soy-based foods e.g. tofu, miso, soy sauce, milk, natto, edamame are major source of daily protein intake 18. In above soy-based foods, soyasaponins were found to constitute a larger proportion as compared to the soyasapogenols (1:85) 19. However, long-term maturated miso was shown to retain a higher content of soyasapogenols 19. Amongst soyasapogenols, content of soyasapogenol B has been found to be higher as compared to soyasapogenol A 19. Several studies on ...