Probiotic yeast induces apoptosis in colon cancer cells

Researchers from the Tabriz University of Medical Sciences in Iran suggest that Pichia kudriavzevii AS-12 has potential anti-cancer activity. They published their results in the journal Nutrition Research.

• The researchers worked under the paradigm that gut microbiota plays an important role in the development of cancer.
• In the study, they proffered that metabolites from P. kudriavzevii secretions contain anticancer activity on human colorectal cancer cells by inhibiting their growth and inducing apoptosis.
• To determine this biological activity and its underlying mechanisms, they performed in vitro tests on P. kudriavzevii. Cytotoxicity was assessed using 3-(4,5-dimethylimidazole-2-yl)-2,5-diphenyltetrazolium bromide assay; 4?,6-diamidino-2-phenylindole staining; and FACS-flow cytometry tests.
• P. kudriavzevii AS-12 secretion metabolites were also tested using real-time polymerase chain reaction method to determine its effects on the expression level of six important genes, namely: BAD, Bcl-2, Caspase-3, Caspase-8, Caspase-9, and Fas-R.
• The results revealed that P. kudriavzevii AS-12 secretion metabolites has notable cytotoxicity on HT-29 cells and Caco-2 (57.5 and 32.5 percent, respectively), compared to KDR/293 normal cells (25 percent).
• The cytotoxic effects displayed by the yeast supernatant on the HT-29 cells were comparable with the positive control 5-fluorouracil (57.5 versus 62.2 percent, respectively). In addition, results from the flow cytometric assay revealed that the primary mechanism behind the anticancer effect of P. kudriavzevii is the induction of apoptosis.
• From the results of the reverse transcriptase polymerase chain reaction, expression levels of pro-apoptotic genes (BAD, Caspase-3, Caspase-8, Caspase-9, and Fas-R) in treated HT-29 cells and Caco-2 cells were higher, compared to untreated and control cells.

In sum, P. kudriavzevii AS-12 secretion metabolites exhibited anti-cancer effects in colon cancer cells.

Journal Reference:

Saber A, Alipour B, Faghfoori Z, Jam AM, Khosroushahi AY. SECRETION METABOLITES OF PROBIOTIC YEAST, PICHIA KUDRIAVZEVII AS-12, INDUCES APOPTOSIS PATHWAYS IN HUMAN COLORECTAL CANCER CELL LINES. Nutrition Research. 2017;41:36–46. DOI: 10.1016/j.nutres.2017.04.001