The Effects of Native Lactobacillus Paracasei Supernatant Solution on Death of Pancreatic Adenocarcinoma Cells (AsPC-1) and Expression of bax, bcl2, and DPC4 Apoptotic Genes

Nowadays, probiotic bacteria such as Lactobacilli have been recognized as promising agents to prevent a large number of diseases, including cancer. This study aimed to evaluate the cytotoxic effects of Lactobacillus paracasei (IBRC_10784) extract on pancreatic cancer cell line ASPc-1 and to analyze the expression of bax, Bcl2, and DPC4 apoptotic genes.

This study was conducted on ASPC-1 pancreatic adenocarcinoma cell line to assess the effects of culture medium and Lactobacillus paracasei products on the expression of genes involved in apoptosis as well as DPC4 gene expression. Lactobacillus paracasei was cultured on specialized MSR broth medium and incubated for 48 hours in a CO2 incubator. After observing the growth of bacteria, the culture medium was centrifuged for 5 minutes at 9000 rpm and the supernatant was removed. Then, the supernatant was sterilized by a 0.22-micron syringe filter and was used in the subsequent steps. In the next step, AsPC-1 cells were treated with supernatant solution for 24 hours, followed by RNA extraction and cDNA synthesis. The Q-PCR reaction was performed using specific primers.

The findings of this research showed that the supernatant solution of Lactobacillus paracasei culture was able to change the expression of the studied genes, so that the expression of bax gene increased 1.86 times relative to the reference gene. Moreover, the expression of bcl-2 gene decreased by 4.56 folds compared to the reference gene. A notable point was the changing expression of DPC4 gene, which significantly increased to 2.67 folds in comparison to the reference gene (P<0.005).

According to the results of the present study, it seems that the increased expression of DPC4 tumor suppressor gene, which is one of the essential factors in TGF-β pathway, may be important in suppressing pancreatic cancer.