Overexpression of cancer stem cell protein, piwil2, promotes the expression of anti-apoptotic and proliferative genes in the gastric cancer cell line mkn-45

Kowsar Moradi,1,* Shiva irani,2 Hamid reza soleimanpour-lichaei2,3

1. Department of Biology, Science and Research branch, Islamic Azad University
2. Department of Biology, Science and Research branch, Islamic Azad University
3. Department of Stem Cells and Regenerative Medicine, National Institute of Genetic Engineering and Biotechnology, Tehran,



piwi-like rna-mediated gene silencing 2 (piwil2) is an oncogene that is highly expressed in different tumors including breast, gastric and colorectal cancer. in addition, piwil2 has an important role in the progression, differentiation and regulation of precancerous stem cells.


This study aimed to determine the effect of piwil2 overexpression on the proliferative and anti apoototic state of mkn-45 as a gastric cancer cell line. to pursue this goal, mkn-45 cell line was stably transfected –via electroporation- with the pcdna3 vector harboring the cdna of hpiwil2 gene under the control of cmv promoter. the generated mkn45-piwil2 cell line was then assessed for its proliferation activity using mtt colorimetric assay and doubling time test. real time pcr and flow cytometry analysis were applied to examine the proliferation and anti-apoptotic state of the mkn45-piwil2 cell line.


Our results showed that mkn45-piwil2 exhibited shorter doubling time compared to non-transfected mkn45 (transfected=21 hours, non-transfected=26 hours). in addition, flow cytometry analysis using annexin v/pi staining showed that hpiwil2 overexpression reduced the apoptotic state of mkn45-piwil2 cell line to 50%. real time analysis indicated that over expression of hpiwil2 promoted the expression of many proliferative and anti-apoptotic genes including pcna ,mki67,ccnd1,stat3, and bcl2l1


In conclusion, our experiments revealed that piwil2 over expression has an important role in the proliferation and anti-apoptotic features of mkn-45 as a gastric cancer cell line. these findings, therefore, shows that piwil2 can play important role in progression and development of gastric cancer


Piwil2-gastric cancer-