Effect of circPUM1 on radioresistance of cervical cancer cells through targeting miR-144-3p.

OBJECTIVE: To investigate the effect of circular RNA pumilio RNA binding family member (circPUM) 1 on radioresistance of cervical cancer cells and its mechanism. METHODS: Cancer tissue and corresponding paricancerous tissue samples were collected from 47 patients with cervical cancer who underwent surgical treatment in the Second Affiliated Hospital of Zhengzhou University from August 2019 to February 2020. The expression levels of circPUM1 and miR-144-3p in cervical cancer tissues and paricancerous tissues were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The Pearson method was used to analyze the correlation between circPUM1 and miR-144-3p expression in cervical cancer tissues. circPUM1 lentiviral short hairpin RNA (sh-circPUM1) and its negative control (sh-NC), miR-144-3p oligonucleotide mimic (miR-144-3p mimic) and its negative control (miR-NC), sh-circPUM1 and miR-144-3p inhibitor (anti-miR), and sh-circPUM1 and anti-miR negative control (anti-miR-NC) were transfected into human cervical carcinoma SiHa cells, respectively, and the cells were irradiated with 0 and 4 Gy irradiation doses. Cell proliferation, colony formation, apoptosis, migration and invasion were detected by cell counting kit (CCK-8 method), plate colony formation assay, flow cytometry and Transwell assay, respectively. The protein expression of cleaved-caspase3 was detected by Western blotting. The targeting relationship between circPUM1 and miR-144-3p was analyzed with Starbase platform. RESULTS: Compared with adjacent tissue, the expression of circPUM1 in cervical cancer tissue was significantly increased ( P<0.05), while the expression of miR-144-3p was decreased ( P<0.05). The circPUM1 was negatively correlated with miR-144-3p ( r=-0.9282, P<0.01). After transfection with sh-circPUM1 or miR-144-3p mimic, the inhibition rate of cell proliferation, the rate of apoptosis and the expression level of cleaved-caspase3 protein increased (all P<0.05), while the number of colonies formed, migrated and invaded cells decreased (all P<0.05). CircPUM1 could targeted to miR-144-3p. After co-transfection of sh-circPUM1 and anti-miR, the inhibition rate of cell proliferation, the rate of apoptosis and the expression level of cleaved-caspase3 protein significantly decreased (all P<0.05), while the number of colonies formed, migrated and invaded cells increased (all P<0.05). CONCLUSION: Silencing circPUM1 may inhibit the proliferation, colony formation, migration, invasion and induce apoptosis of cervical cancer cells through targeting and regulating the expression of miR-144-3p.