[LncRNAs: new approach in cancer therapy]

LncRNAs are non-coding transcripts with more than 200 nucleotides in length which interact to other molecules through their particular molecular structures and affect on numerous molecular processes. Key functions of lncRNAs in a great variety of cell pathways have been significantly studied. These molecules are expressed in many various cell types, but their decreased or increased expression has been reported in different diseases, especially cancer. Published papers have introduced lncRNAs and their crucial roles in primary steps of tumorigenesis, tumor development and apoptosis. lncRNAs importance in cancer occurrence is so remarkable that level measurement of some of them may be a considerable aid in diagnosis or prognosis of related cancer. Furthermore, a variety of new therapeutic approaches are innovated based on inhibition or enhancement of lncRNAs functions for alleviation disease severity however, they are conceivable only in research concept. In the current article, these approaches and their related molecular basis are conveyed by the use of the newest reliable resources

[lncRNAs roles in cancer occurrence]

Cancer is a complex condition in which gene expression is disrupted. Genetic factors involved in cancer pathology have been studied significantly. However, evidences have documented that a considerable fraction of susceptibility to cancer is not attributable to changes in protein coding sequences. Discovery and identification of a vast repertory of long noncoding RNAs [lncRNAs] with more than 200 nucleotides in human have been associated to unveiling their roles in tumorigenesis. Importance of lncRNAs, as either tumor suppressive or oncogenic agents, has been demonstrated in various common cancers. Recent studies indicate that several risk loci contributing to cancer pathogenesis are transcripted to lncRNAs which have critical roles in cancer incidence. Fundamental mechanisms of lncRNAs functions in a variety of gene expression levels involving epigenetic modification and transcriptional or post-transcriptional regulation, as well as interaction of these RNAs with other critical molecules such as DNA and some of proteins with definitive roles in cell fate have been described previously in detail by authors. Since a remarkable part of cancer pathogenesis has been reported in related to lncRNAs, the current review article discusses about association of some lncRNAs with specific tumors, effects of lncRNAs on cancer incidence and their importance in providing diagnostic and prognostic opportunities

[lncRNAs: significance and function mechanisms]

In mammals, the majority of products of gene expression are non-coding ribonucleotide sequences. They include short and long RNA molecules with sizes ranging of tens to hundreds of nucleotides. Among them, the molecules with more than 200 nucleotides are called long non-coding RNAs or lncRNAs. While LncRNAs functions depend on their unique molecular structures, they play important roles in regulating gene expression at epigenetic, transcriptional and post-transcriptional levels. Interacting with other biological molecules such as DNA, RNA and protein, LncRNAs have been found to play important roles in normal cell physiological activities. Activation of transcription factors, guidance of ribonucleoprotein complexes, aggregation of partner proteins, regulation of alternative processing, cooperation in chromatin remodeling, facilitation of genomic imprinting, maintaining of multipotential state and control of nucleus/cytoplasm traffic are some of crucial approaches Implemented by LncRNAs. Modern technologies have been developed to identify lncRNA molecules, and many relevant databases have been designated to facilitate research and academic exchange of data concerning them. In this review article, signification, identification, classification, biological evolution, genomic position, configuration, expression, localization and remarkable functions of LncRNAs have been discussed