Association study of SNPs in LncRNA CDKN2B-AS1 with breast cancer susceptibility in Chinese Han population

Background: The study aimed to analysis the genetic variation of the lncRNA CDKN2B-AS1 SNPs, and explored the regulation of SNPs on the invasion and metastasis of Breast cancer (BC). Methods: The SNPs (Single Nucleotide Polymorphisms) was screened for genotyping among 504 Chinese Han patients and 505 controls, which were frequency-matched for age (+/- 2 years). Logistic analysis was to explore the relationship between SNPs and the BC risk. Interactions between SNPs and reproductive factors was explored using the multifactor dimensionality reduction (MDR) method. qRT-PCR was conducted to detect the CDKN2B-AS1 expression in plasma of different rs10965215 and rs2518723 genotypes. The effect of rs10965215 A>G mutation on the binding ability of CDKN2B-AS1 and miR-4440 was verified by dual luciferase experiment. CCK-8, scratch and Transwell experiment were performed to explore the effect of miR-4440 over-expression on BC cell proliferation, migration and invasion. Results: A total of 13 SNP was screened. The individuals with SNPs rs2518723C>T, rs10965215 A>G, rs77792598C>G, rs4977753 T > C, rs75917766C>T and rs78545330C>G mutations might increase the BC risk. MDR results revealed that individuals with rs10965215 G genotype who age at menarche >= 13 and regardless of the number of abortion< 2 or >= 2 had a higher risk of BC. The relative expression of CDKN2B-AS1 in rs10965215 homozygous wild AA genotype (8.88 +/- 3.43) was lower than heterozygous GA (11.08 +/- 2.90) and homozygous mutant GG genotype (11.31 +/- 2.90). When rs10965215 wild A genotype was carried, there was an interaction between CDKN2B-AS1 and miR-4440. The CCK-8, Transwell, and scratch experiment were all found that miR-4440 over-expression might enhance the proliferation, invasion and migration of BC cells. Conclusion: CDKN2B-AS1 gene polymorphism might be related to the susceptibility of BC, CDKN2B-AS1 rs10965215 A/G genotype probably affect the proliferation, invasion and migration of BC cells by modulating the interactions with of miR-4440.