Regulation of closely juxtaposed proto-oncogene and gene expression by mRNA 3' end polymorphism in breast cancer cells.

Sense-antisense mRNA pairs generated by convergent transcription is a way of gene regulation. gene is closely juxtaposed to the gene in the opposite orientation, in chromosome 5. The intergenic region (IR) between and genes is 162 bp. We found that a small portion (∼4.18%) of mRNA is transcribed further downstream, including the end of the gene generating antisense mRNA against mRNA. Similarly, a small portion (∼1.1%) of mRNA is transcribed further downstream, including the end of the gene generating antisense mRNA against the mRNA. Insertion of the strong poly(A) signal sequence in the IR results in decreased and antisense mRNAs, resulting in up-regulation of both and mRNA expression. miR-324-5p targets mRNA 3' UTR, and as a result, regulates mRNA expression. HuR stabilizes mRNA, and as a result, down-regulates mRNA expression. UALCAN analysis indicates that the expression pattern between and HMGXB3 proteins are opposite in vivo in breast cancer tissues. Together, our results indicate that the mRNA encoded by the gene can influence the expression of adjacent mRNA, or vice versa.