RESUMO
Makorin RING finger protein 3 (MKRN3) is a key inhibitor of the hypothalamic-pituitary-gonadal (HPG) axis. The association between MKRN3 gene variants and central precocious puberty (CPP) has been repeatedly examined. In a recent study, MKRN3 has been assigned a role of tumor suppressor in lung carcinogenesis. Therefore, it is hypothesized that MKRN3 may be the link between CPP and lung cancer (LC), and certain MKRN3 gene variants may affect individuals' susceptibility to CPP and LC. The rs12441287, rs6576457 and rs2239669 in the MKRN3 gene were selected as the target variants. Sanger sequencing was applied to genotype them in two sets of case-control cohorts, namely 384 CPP girls and 422 healthy girls, 550 LC patients and 800 healthy controls. The results showed that rs6576457 but not rs12441287 or rs2239669 was significantly associated with the risk of CPP and LC. Their association with CPP risk was further confirmed in the following meta-analysis. Subsequent functional assays revealed that the rs6576457 genotypes were correlated with differentially expressed MKRN3, and the rs6576457 alleles affected the transcription repressor Oct-1 binding affinity to the MKRN3 promoter. Collectively, the MKRN3 gene rs6576457 may participate in the CPP pathology and LC tumorigenesis in the Hubei Chinese population. However, the present findings should be validated in additional investigations with larger samples from different ethnic populations.