Zahra Shishegar - Department of Genetics, Faculty of Biological Sciences and Technology, Shahid AshrafiEsfahani University, Isfahan, Iran
Tahereh Sadeghian-Rizi - Department of Biotechnology, Faculty of Biological Sciences and Technology, ShahidAshrafi Esfahani University, Isfahan, Iran

RNA is a messenger between a coding gene and protein encoded by it. Only۲% of the RNAs, encode proteins in human cells. Generally, non-codingRNAs (ncRNAs) are divided into two groups, short noncoding RNAs (<۲۰۰Nuc) and long noncoding RNAs (LncRNAs, >۲۰۰ Nuc). LncRNAs aredefined by two characteristics, lack of protein-coding potential and beinglonger than ۲۰۰ nucleotides (۲۰۰-۱۰۰۰۰۰). LncRNAs are transcribed by theenzyme RNA polymerase II or III. Similar to mRNAs, most lncRNAs are ۵ ׳capped, spliced, and polyadenylated after transcription. Compared tomRNAs, lncRNAs contain fewer but longer exons and their expression levelsacross different tissues are commonly lower. Research studies reveal thatlncRNAs are aberrantly expressed in various types of cancer cells andcontribute to the initiation and development of several common hallmarks ofcancer including apoptosis, cell migration, angiogenesis, invasion,proliferation, and also they involve in autophagy. LncRNAs apply theirregulatory mechanisms during transcription, post transcription, epigeneticchanges, and signaling pathways. The LncRNAs can form lncRNA-miRNAmRNAaxis called “ceRna” networks which these regulatory networks play asignificant role in pathogenesis and promotion of tumor malignancies likebreast, colorectal, stomach, liver, lung, and thyroid cancer. Since changes inthe lncRNAs expression are related to cancer formation and progression,many studies are focused on the potential of LncRNAs in prognosis,diagnosis, and therapy of cancers.

cancer, long noncoding RNA (lncRNA), gene expression,regulatory functions, lncRNA-miRNA-mRNA axis