HOX transcript Antisense Intergenic RNA Role in Breast Cancer; Review Article

Abstract

Genomic and transcriptomic analyses have revealed that as much as 85% of the human genome is transcribed. Non-coding regions of the genome were considered nothing more than transcriptional noise but now it is believed that they have a larger and more diverse role in biological processes than initially anticipated. Non-coding RNAs (ncRNAs) can be roughly classified into two groups based on their size. One group includes short RNAs less than 200 nucleotides (nt) in length, such as microRNAs (miRNAs) as well as, tRNA and piwi-interacting RNAs (piRNAs). The other group includes long ncNAs (lncRNAs) of around 200 nt or more. Cancer is a condition where gene expression is aberrant. The study of genetic background of cancer has revealed that the majority of the cancers are attributed to non-coding regions of the genome. Recent developments indicate that several cancer loci are transcribed into lncRNAs and that these transcripts play key roles in tumor genesis. LncRNAs contribute to cancer development through diverse mechanisms. For example, lncRNAs interact with nucleic material and protein molecules and/or their combinations and act as an essential regulator of chromatin organization, transcriptional and posttranscriptional regulation. Their misexpression confers the cancer cell potential to initiate tumor growth, and metastasis.