Study on the Molecular Mechanism of the Influence of circCALN1/miR-143-3p/BCL-2 Regulatory Axis on the Proliferation and Invasion of Nasopharyngeal Carcinoma Cells

JIANG Hao¹*, LIAO Jinlong¹, CHEN Shuhua², LU Mang¹, YANG Ruiliang¹, HE Jinhua³

(¹Foshan Hospital Affiliated to Southern Medical University/Pathology Department of Foshan Second People’s Hospital, Foshan 528000, China; ²Foshan Hospital Affiliated to Southern Medical University/Otolaryngology Department of Foshan Second People’s Hospital, Foshan 528000, China; ³Laboratory Department of Panyu Central Hospital, Guangzhou 511400, China)

Abstract:

This sudy was to investigate the molecular mechanism of circCALN1 expression in NPC (nasopharyngeal carcinoma). The miRNA regulated by circCALN1 and the target gene regulated by miRNA were predicted by the bioinformatics software and the relative gene expression levels in NPC tissues and cell lines were detected by RT-PCR; CNE1, HNE1, SUNE-1, 5-8F, 6-10B, NP69, 293T cell lines were cultured in conventional culture; the siRNA sequences for the junction of circCALN1 and BCL-2 were designed and transfected with liposome; Transwell assay was used to detect cell invasion ability, MTT assay was used to detect cell proliferation inhibition rate, Western blot was used to detect the relative expression of protein, and double fluorescent reporter gene vector was constructed to verify the binding site between genes; the expression of circCALN1, BCL-2 were up-regulated in NPC tissues and cell lines; after 24, 48 and 72 h when knock down the expression of circCALN1 and BCL-2, the inhibition rates were (16.3±1.65)%, (29.6±2.6)%, (63±3.6)%, (26.3±2.9)%, (32.6±3.8)% and (59.6±3.9)%, respectively; after overexpression of miR-143-3p for 24, 48 and 72 h, the inhibition rates were (9.6±3.6)%, (13.6±5.6)%, (36.8±2.3)%; Overexpression of miR-143-3p and decreased expression of circCALN1and BCL-2, the number of invasive cells were 185±13, 200±15, 183±18; bioinformatics results showed that there were binding sites between miR-143-3p and circCALN1, and between miR-143-3p and BCL-2. The plasmid of circCALN1, BCL-2-3ʹUTR double fluorescent reporter gene vector and miR-143-3p mimics were co-transfected into 293T cells, and the fluorescent activity was decreased. The knock down expression of circCALN1 promoted the up-regulation of miR-143-3p, while down regulated expression level of BCL-2. The regulatory axis of circCALN1/miR-143-3p/BCL-2 affects the proliferation and invasion of NPC.