Interaction of LNCRNA CCAT1 and MXD1 gene in different cancer cells

Cancer is a major public health problem and is one of the leading causes of death worldwide. Cancer formation and progression are still not well-known processes despite extensive research of molecular basis of cancer. Long non-coding RNAs (lncRNAs) are non-coding RNA molecules longer than 200 nucleotides. LncRNAs are involved in the regulation of gene expression at the transcriptional and translational levels. Mutations and misregulation of lncRNAs are found to be related with several stages of cancer. Acording to recent studies, CCAT1 lncRNA was found to regulate chromatin interactions of the MYC gene. The MYC proto-oncogene is a member of the MYC/MAX/MXD1 network that affects normal cell behaviours in many aspects. MYC-MAX complex acts as a transcriptional activator by forming sequence-specific DNA-binding complex while MXD1 binds to MAX via competiting with MYC and acts as a transcriptional repressor. In our study, it was aimed to investigate the interaction between CCAT1 lncRNA and MXD1 genes. For this purpose, different cancer cell lines were transfected with CCAT1 siRNA and MXD1 siRNA separately and the changes in expression levels of CCAT1 lncRNA, MXD1 and MYC genes were analyzed by RTPCR method. The effects on apoptosis and cell cycle were investigated by flow cytometric analysis method. In addition, two different bioinformatics analysis methods were used to investigate the possible interaction between CCAT1 and MXD1. As a result, it was determined that there may be direct or indirect opposite interactions between CCAT1 lncRNA and MXD1 gene in A549 cell line. This interaction is supported by bioinformatics analysis. Studies on understanding the molecular mechanisms of long non-coding RNAs in cancer formation will enable the development of lncRNAs as diagnostic markers or new treatment strategies against cancer.