The Effect of Therapeutic Klotho Protein on Cell Viability in HT-29 Cell Line

Abstract Several studies have shown that klotho protein plays an important role in tumorigenesis concerning cell viability, proliferation, senescence, survival, autophagy, and resistance to antitumor therapies. From the literature, there is no study has been analyzed that the klotho protein induces cytotoxic effects on human colorectal adenocarcinoma or healthy colon cells. We aimed to investigate the anticancer effects of klotho protein against the human colon adenocarcinoma cells and the selectivity using healthy colon cells by adding exogenously klotho protein to the medium of HT-29 cancer and the CCD 841 CoN healthy cell lines and analyzing its effect on cell viability and apoptosis process. The half-maximal inhibitory concentration (IC50) of the human klotho protein was analyzed by WST-8 assay. Annexin V-PI flow cytometric analysis and AO-PI fluorescent staining techniques were used to test the effect of klotho protein on cancer and healthy colon cells for measuring the percentage of cells undergo apoptotic. Our results have firstly demonstrated that klotho had a cytotoxic effect against colorectal adenocarcinoma cells in a dose-dependent manner. Annexin V-PI flow cytometric and AO-PI fluorescent analyses found that klotho induced quantitative and morphological changes that indicate the apoptotic induction in the human colorectal adenocarcinoma. This study results proved for the first time that klotho may be an effective potential therapeutic agent that may be used in adjuvant therapy in human colorectal adenocarcinoma because it does not affect selectively healthy colon cells and but leading cancer cells to apoptosis.