lincRNA-RP11400K9.4 Regulates Cell Survival and Migration of Breast Cancer Cells.

Background/aim: Several works in the past decades pointed out the key role of long intergenic non-coding RNA (lincRNA) in breast cancer development. Here in we report for first time the importance of deregulation of lincRNA RP11-400K9.4 in breast cancer cells which played a role in cell survival and migration.

Materials And Methods: After RP11-400K9.4 silencing by short hairpin RNAs or overexpression by GeneBlocks, real-time quantitative polymerase chain reaction (RT-PCR), microarray, migration, proliferation and viability assay were performed.

Results: RP11-400K9.4 expression was mainly in the cytoplasmic fraction in 2D culture. Overexpression of RP11-400K9.4 led to a reduction of migration by MCF-7 and MDA-MB-368 cells and an increase in cellular survival after UV-C radiation. Bioinformatic analyses highlighted irradiation-induced DNA damage, DNA repair and cell-cycle pathways as the mainly affected by RP11-400K9.4. Furthermore RT-PCR assay demonstrated the overexpression of baculoviral IAP repeat containing 3 (BIRC3) a known oncogene that promotes radiotherapy resistance through the nuclear factor kappa B (NFĸB) pathway.

Conclusion: RP11-400K9.4 participates in the modulation of migration and survival processes probably via the BIRC3/NFĸB pathway.