In-vitro antioxidant and selective cytotoxicity of Garcinia cambogia and Garcinia indica leaf extracts on human kidney cancer cell line

Kidney cancer is one among the top 10 cancers. Renal cell carcinoma (RCC) is commonly known kidney cancer. Almost all clinically targeted drugs used in treating RCC have many aftereffects. To overcome this problem with herbal products, the present study is aimed to investigate the preliminary phytochemicals, antioxidants and selective cytotoxicity of aqueous leaves extract of Garcinia cambogia (GC)and Garcinia indica (GI)on(HEK-293) human embryonic kidney cells and (A498)human renal carcinoma cells. The phytochemical analyses were done using standard protocols. In-vitro antioxidant activity was carried out using DPPH, FRAP, and Phosphomolybdenum assay. Anticancer activity on A498 kidney cancer cell line was evaluated by MTT assay and the selectivity index was calculated. Preliminary phytochemical analysis of GC and GI leaf extract divulged the presence of various phyto-constituents. GI extract revealed higher phenolic content while flavonoid content was more in GC extract compared to alkaloids and saponins. Both plant extracts exhibited higher antioxidant capacities based on the test performed.GC and GIleaf extract wasselectively cytotoxic in-vitro to (A498) human renal carcinoma cells and can be safely used against kidney cancer at 500 µM (GC extract)and 300 µM (GI extract). Selective index for GC and GI extract was15.9 and 2.4respectively. The results indicate that GC and GI extracts are a favourable antioxidant and anti-cancer agents for A498 human renal carcinoma cells. However, further studies to isolate the bioactive compounds responsible for these activities are underway and to explore their molecular mechanism.

Alternol Sensitizes Renal Carcinoma Cells to TRAIL-Induced Apoptosis

Purpose: Tumor necrosis factor–related apoptosis-inducing ligand (TRAIL), a member of the TNF family, can selectively induce cancer cell death while sparing normal cells. However, the application of TRAIL-based antitumor therapies has been hindered due to drug resistance. Alternol is a new compound isolated from microbial fermentation that possesses antitumor activity in different tumors. In our research, we discovered that alternol can sensitize TRAIL-induced apoptosis in renal carcinoma cells (RCCs).Materials and Methods: Cytotoxic activity was measured by MTT assay. Apoptosis was probed using the PI/annexin V method. Real-time PCR and western blot were used to test the levels of mRNA and protein, respectively. Luciferase assay was used to investigate whether CHOP regulated the expression of death receptor (DR) 5 through transcription. A xenogeneic tumor transplantation model was used to evaluate the anticancer effects of alternol/TRAIL in vivo.Results: When the mechanisms were investigated, we discovered that alternol increased DR5 expression. DR5 knockdown by siRNA eliminated the enhanced effect of alternol on TRAIL-mediated apoptosis. Alternol reduced the expression of antiapoptotic proteins and increased the levels of proapoptotic proteins. Moreover, alternol increased the level of CHOP, which is necessary for the enhancing effect of alternol on TRAIL-induced apoptosis, given that downregulation of CHOP abrogated the synergistic effect. DR5 upregulation induced by alternol required the production of reactive oxygen species (ROS). Removing ROS inhibited the induction of DR5 and blocked the antiapoptotic proteins induced by alternol.Conclusion: Taken together, our research suggested that alternol increased TRAIL-mediated apoptosis via inhibiting antiapoptotic proteins and upregulating DR5 levels via ROS generation and the CHOP pathway.

Cooperative Blockade of CK2 and ATM Kinases Drives Apoptosis in VHL-Deficient Renal Carcinoma Cells through ROS Overproduction

Kinase-targeted agents demonstrate antitumor activity in advanced metastatic clear cell renal cell carcinoma (ccRCC), which remains largely incurable. Integration of genomic approaches through small-molecules and genetically based high-throughput screening holds the promise of improved discovery of candidate targets for cancer therapy. The 786-O cell line represents a model for most ccRCC that have a loss of functional pVHL (von Hippel-Lindau). A multiplexed assay was used to study the cellular fitness of a panel of engineered ccRCC isogenic 786-O VHL− cell lines in response to a collection of targeted cancer therapeutics including kinase inhibitors, allowing the interrogation of over 2880 drug–gene pairs. Among diverse patterns of drug sensitivities, investigation of the mechanistic effect of one selected drug combination on tumor spheroids and ex vivo renal tumor slice cultures showed that VHL-defective ccRCC cells were more vulnerable to the combined inhibition of the CK2 and ATM kinases than wild-type VHL cells. Importantly, we found that HIF-2α acts as a key mediator that potentiates the response to combined CK2/ATM inhibition by triggering ROS-dependent apoptosis. Importantly, our findings reveal a selective killing of VHL-deficient renal carcinoma cells and provide a rationale for a mechanism-based use of combined CK2/ATM inhibitors for improved patient care in metastatic VHL-ccRCC.