Saber Amir, Alipour Beitollah, Faghfoori Zeinab, Mousavi Jam Ali, Yari Khosroushahi Ahmad
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.
Nutr Res. 2017 May;41:36-46. doi: 10.1016/j.nutres.2017.04.001. Epub 2017 Apr 18.
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 < .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.
胃肠道微生物群在癌症病因学中的重要作用已得到普遍认可。良性益生菌酵母菌株能够改善肠道微生物群，并通过抗炎、抗增殖和抗癌作用调节宿主代谢、生理和免疫系统。我们假设库德里亚夫齐毕赤酵母AS-12分泌代谢产物通过抑制生长和诱导凋亡对人结肠癌细胞（HT-29、Caco-2）具有抗癌活性。本研究旨在评估库德里亚夫齐毕赤酵母AS-12分泌代谢产物的抗癌作用及其潜在机制。通过3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四氮唑溴盐法、4',6-二脒基-2-苯基吲哚染色和流式细胞术检测进行细胞毒性评估。此外，采用实时聚合酶链反应法研究了库德里亚夫齐毕赤酵母AS-12分泌代谢产物对参与外源性和内源性凋亡途径的6个重要基因（BAD、Bcl-2、Caspase-3、Caspase-8、Caspase-9和Fas-R）表达水平的影响。与KDR/293正常细胞（25%）相比，库德里亚夫齐毕赤酵母AS-12分泌代谢产物对HT-29细胞（57.5%）和Caco-2细胞（32.5%）显示出显著的（P < 0.0001）细胞毒性作用。此外，作为阳性对照，所检测的酵母上清液对HT-29细胞的细胞毒性作用与5-氟尿嘧啶相当（分别为57.5%对62.2%）。流式细胞术结果表明，诱导凋亡是抗癌作用的主要机制。此外，根据逆转录酶聚合酶链反应结果，处理后的HT-29和Caco-2细胞中促凋亡基因（BAD、Caspase-3、Caspase-8、Caspase-9和Fas-R）的表达水平高于未处理细胞和正常细胞，而抗凋亡基因（Bcl-2）则下调。库德里亚夫齐毕赤酵母AS-12分泌代谢产物通过抑制细胞增殖以及诱导结肠癌细胞的内源性和外源性凋亡发挥其抗癌作用。
