Association analyses of genetic variants in long non-coding RNA MALAT1 with breast cancer susceptibility and mRNA expression of MALAT1 in Chinese Han population.

The long non-coding RNA (lncRNA) Metastasis-associated lung adenocarcinoma transcript 1(MALAT1) has been implicated in breast cancer (BC). Polymorphisms in MALAT1 may play a vital role in the progress of breast cancer by its regulation function. However, potential genetic variants in MALAT1 affecting the development of BC is rarely explored. In our current molecular epidemiology study, all three tagging SNPs (rs3200401, rs619586 and rs7927113) in lncRNA MALAT1 were selected for genotyping in 487BCE patients and 489 cancer-free controls in Chinese Han population, and futher experiment of quantitative real-time (qRT) PCR was conducted to examine the relative expression of MALAT1. The results showed that individuals with genotype AG of rs619586 has a decreased risk of BC in codominant model (OR: 0.684, 95%CI: 0.478-0.979), dominant mode (OR: 0.675, 95%CI: 0.479-0.951) and over-dominant model (OR: 0.692, 95%CI: 0484-0.989). Also, qRT-PCR results revealed that the expression for MALAT1 with AG (0.827±0.490), GG (0.511±0.149) and AG+GG genotypes (0.743±0.447) of rs619586 was significantly lower than that with genotype AA (1.511±0.737). In addition, females with genotype CT of rs3200401 had a lower risk of BC in the codominant model (OR: 0.75, 95%CI: 0.559-1.007) and over-dominant model (OR: 0.741, 95%CI: 0.552-0.993). In summary, our results implied that the genetic variants of lncRNA MALAT1 were associated with the susceptibility of BC, and meaningful genetic alteration might affect the corresponding mRNA expression of lncRNA MALAT1.