Secretion metabolites of probiotic yeast, Pichia kudriavzevii AS-12, induces apoptosis pathways in human colorectal cancer cell lines
Authors: Beitollah Alipour
Ahmad Yari Khosroushahi
Zeinab Faghfoori
Amir Saber
Ali Mousavi Jam
Journal: Nutrition Research (2017)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: Antiproliferation; Apoptosis; Secretion metabolites; Yeast.
Affiliations: Biotechnology Research Center, Faculty of Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran; Student Research Committee, Faculty of Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Biochemistry and Diet Therapy, Faculty of Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran., Department of Biochemistry and Diet Therapy, Faculty of Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran; Nutrition Research Center, Faculty of Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran. Electronic address: ., Semnan University of Medical Sciences, Semnan, Iran., Department of Biochemistry and Diet Therapy, Faculty of Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran; Nutrition Research Center, Faculty of Nutrition, Tabriz University of Medical Sciences, Tabriz, Iran., Drug Applied Research Center, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Pharmacognosy, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran. Electronic address: .

Abstract:  There is a common agreement on the important role of the gastrointestinal microbiota in the etiology of cancer. Benign probiotic yeast strains are able to ameliorate intestinal microbiota and regulate the host metabolism, physiology, and immune system through anti-inflammatory, antiproliferative, and anticancer effects. We hypothesized that Pichia kudriavzevii AS-12 secretion metabolites possess anticancer activity on human colorectal cancer cells (HT-29, Caco-2) via inhibiting growth and inducing apoptosis. This study aimed to assess the anticancer effect of P. kudriavzevii AS-12 secretion metabolites and the underlying mechanisms. The cytotoxicity evaluations were performed via 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide assay; 4',6-diamidino-2-phenylindole staining; and FACS-flow cytometry tests. Also, the effects of P. kudriavzevii AS-12 secretion metabolites on the expression level of 6 important genes (BAD, Bcl-2, Caspase-3, Caspase-8, Caspase-9 and Fas-R) involved in the extrinsic and intrinsic apoptosis pathways were studied by real-time polymerase chain reaction method. P. kudriavzevii AS-12 secretion metabolites showed significant (P &lt; .0001) cytotoxic effects on HT-29 cells (57.5%) and Caco-2 (32.5%) compared to KDR/293 normal cells (25%). Moreover, the cytotoxic effects of examined yeast supernatant on HT-29 cells were comparable with 5-fluorouracil, as a positive control (57.5% versus 62.2% respectively). Flow cytometric results showed that the induction of apoptosis is the main mechanism of the anticancer effects. Also, according to the reverse transcriptase polymerase chain reaction results, the expression level of proapoptotic genes (BAD, Caspase-3, Caspase-8, Caspase-9, and Fas-R) in treated HT-29 and Caco-2 cells was higher than untreated and normal cells, whereas the antiapoptotic gene (Bcl-2) was downregulated. P. kudriavzevii AS-12 secretion metabolites exert its anticancer effects by inhibiting cell proliferation and inducing intrinsic and extrinsic apoptosis in colon cancer cells. 

Retracted: No

PubPeer comments:
 Figure 3. Some groups of cells appear to also be visible in Figure 2 of another paper by the same authors. That paper is: * Amir Saber et al. - Prophylactic Effects of Dairy Kluyveromyces marxianus YAS through Overexpression of BAX, CASP 3, CASP 8 and CASP 9 on Human Colon Cancer Cell Lines - International Journal of Biological, Biomolecular, Agricultural, Food and Biotechnological Engineering Vol:10, No:3, 2016 - DOI: 10.5281 zenodo.1112047 - https: pubpeer.com publications 5E73EE85DE81ECDA3DB9EFF35F4057 Of note, the cells represent different cell lines and treatments, and are shown with different groups of adjacent cells. Boxes of the same color highlight areas that look similar to each other. ![file] , 
 Figure 4. * Red boxes: Panels A (untreated HT-29 cells) and G (untreated KDR.293 cells) appear to look very similar. ![file] ,