The Journal of Practical Medicine ›› 2022, Vol. 38 ›› Issue (12): 1475-1485.doi: 10.3969/j.issn.1006⁃5725.2022.12.007

• Basic Research • Previous Articles     Next Articles

Effects of methyl methansulfonate and UV sensitive gene clone 81 on proliferation，apoptosis and chemo⁃ sensitivity of MCF ⁃7 human breast cancer cell line 

CHANG Yingzhi*，ZHAO Li，ZHANG Nianwei，XIONG Baiyu，WU Fan.    

  1. Department of Breast Surgery，Guangzhou First People′s Hospital，the Second Affiliated Hospital of South China University of Technology，Guangzhou 510180，China

  • Online:2022-06-25 Published:2022-06-25

Abstract:

Objective To study the effect of Mus81 gene silencing on the proliferation，apoptosis and chemosensitivity of MCF ⁃7 human breast cancer cell line，and to preliminarily explore its regulatory mechanism. Methods Mus81⁃silenced MCF ⁃7 breast cancer cell line was initially constructed. Cell growth and proliferation were detected by thiazolyl blue（MTT）method and plate cloning assay. Propidium iodide（PI）staining and Annexin V⁃APC staining were used to detect changes in cell cycle and apoptosis. qRT⁃PCR detected the expression of down⁃ stream genes after Mus81 was silenced，and MTT method detected the 50% inhibitory concentration（IC50）and reversal index（RI）of chemotherapy drugs. Results The MTT growth curve and plate cloning assay showed that the proliferation of MCF ⁃7 cell line was significantly retarded after Mus81 gene silencing（P < 0.001），and the number of cell clones was significantly decreased（P < 0.001）. Annexin V ⁃APC and PI staining showed that the apoptotic rate of MCF⁃7 cells increased（P < 0.001），and obvious G2/M phase arrest developed. MTT test results showed that the IC50 values of MCF ⁃7 cells to cisplatin，doxorubicin，epirubicin and 5⁃fluorouracil were signifi⁃ cantly reduced after Mus81 silencing，and the RI was 5.118，3.070，3.027 and 8.997 respectively. The results of qRT⁃PCR and Western blot for detecting the expression of downstream signaling pathways showed that the expres⁃ sions of APAF1，APC and PTEN genes in MCF⁃7 cells increased after Mus81 silencing，while the expressions of MAPK3 and MAPK1 genes decreased. Conclusions Mus81 gene silencing can significantly inhibit the growth and proliferation of the MCF⁃7 human breast cancer cell line and induce G2/M phase arrest and apoptosis. It can also increase the sensitivity of MCF ⁃ 7 cells to cisplatin，doxorubicin，epirubicin and 5⁃fluorouracil. The mechanismmay be related to the regulation of the expressions of downstream genes APAF1，APC，PTEN，MAPK1 and MAPK3， suggesting that Mus81 may be a potential therapeutic target of breast cancer.

Key words:

methyl methanesulfonate and UV sensitive gene clone 81, breast cancer, proliferation, apoptosis, chemosensitivity