Many cervical cancer (CC) patients suffer from cancer invasion and lymph node metastasis, resulting in poor therapeutic outcome. Evidence has indicated the involvement of misexpressed high-mobility group AT-hook 2 (HMGA2) in poor survival of cancer patients. This study hereby aims to investigate the role of HMGA2 in CC cell biological functions via the ATR/Chk1 signaling pathway. The cell line with the highest HMGA2 expression was selected to establish cell lines with wild-type and stable HMGA2 silencing. The underlying regulatory mechanisms of HMGA2 in CC cells were analyzed with the treatment of the ATR/Chk1 signaling pathway activator, inhibitor, shRNA against HMGA2 or pcDNA-HMGA2 plasmids, followed by quantification of expression levels of ATR, Chk1, Bcl-2, Bax, MMP-2, MMP-9, E-cadherin and N-cadherin. CC cell apoptosis, proliferation, migration, invasion and lymph node metastasis in nude mice were evaluated. The HeLa cell line with the highest HMGA2 expression was selected. HMGA2 inhibited the activation of the ATR/Chk1 signaling pathway. Notably, HMGA2 silencing or inhibition of the ATR/Chk1 signaling pathway inhibited epithelial mesenchymal transition (EMT), CC cell proliferation, invasion, migration, tumorigenicity and lymph node metastasis while promoting apoptosis, indicated by reduced expression of Bcl-2, MMP-2, MMP-9 and N-cadherin, with increased expression of E-cadherin and Bax. Collectively, our study provides evidence that HMGA2 gene silencing inhibits the activation of the ATR/Chk1 signaling pathway, whereby repressing EMT, proliferation, migration and invasion of CC cells and lymph node metastasis, and promoting CC cell apoptosis.
Keywords: ATR/Chk1 signaling pathway; HMGA2; cervical cancer; epithelial mesenchymal transition; lymph node metastasis.