Structural Maintenance of Chromosomes 1A (SMC1A) regulated by KIAA1429 in m6A-independent manner promotes EMT progress in breast cancer
Abstract Background As a component in the m6A ‘writers’, KIAA1429 was reported to promote breast cancer proliferation and growth in m6A-independent manners. However, the related mechanism of KIAA1429 in breast cancer metastasis have not been reported. Methods Western blots and quantitative real-time PCR were carried out to verify the expression of KIAA1429 in breast cancer cells SUM1315 and ZR-75-1 after KIAA1429 knockdown or overexpression. Transwell and in vivo metastasis assay were conducted to investigate the effects of KIAA1429 on migration and invasion of breast cancer cells. RIP and REMSA assay was performed to explore the direct correlation between KIAA1429 and SMC1A mRNA. ChIP assay combined with luciferase reporter assay were apply to explore the direct binding between SMC1A and SNAIL promotor region. Results KIAA1429 could significantly promote the migration and invasion of breast cancer cells. Knockdown of KIAA1429 could impede breast cancer metastasis in nude mice in vivo. The level of SNAIL expression and EMT progress was positively related with KIAA1429. Knockdown of KIAA1429 induced cell migration, invasion and EMT progress could be reversed by the upregulation of SNAIL. However, SMC1A, not KIAA1429 bound with SNAIL promoter region directly and promoted the transcription of SNAIL. Then, KIAA1429 could bind to the motif in the 3′-UTR of SMC1A mRNA directly and enhanced SMC1A mRNA stability. Conclusions In conclusion, our study revealed a novel mechanism of the KIAA1429/SMC1A/SNAIL axis in the regulation of invasion and metastasis of breast cancer, which may provide a potential biomarker and therapeutic target for breast cancer. Moreover, it firstly provided compelling evidences that KIAA1429 could regulate the targeted gene expression at posttranscriptional levels as an RNA-binding protein, unrelated the m6A modification.