The function of novel small non-coding RNAs (piRNAs, tRFs) and PIWI protein in colorectal cancer

Interactions of piRNAs with the mRNA of Candidate Genes in Esophageal Squamous Cell Carcinoma

Recently, a database of human piRNAs (piwi-interacting RNAs) was created, which allows the study of the binding of many piRNAs to the mRNAs of genes involved in many diseases, including cancer. In the present work, we identified the piRNAs that can interact with candidate esophageal squamous cell carcinoma (ESCC) genes. The binding of 480 thousand piRNAs with the mRNAs of 66 candidate ESCC genes was studied. Bioinformatic studies found that piRNAs bind only to the mRNAs of nine candidate genes: AURKA, BMP7, GCOM1, ERCC1, MTHFR, SASH1, SIX4, SULT1A1, and TP53. It has been shown that piRNAs can bind to mRNA by overlapping nucleotide sequences in limited 3'UTR and 5'UTR regions called clusters of binding sites (BSs). The existence of clusters of piRNA BSs significantly reduces the proportion of the nucleotide sequences of these sites in the mRNA of target genes. Competition between piRNAs occurs for binding to the mRNA of target genes. Individual piRNAs and groups of piRNAs that have separate BSs and clusters of BSs in the mRNAs of two or more candidate genes have been identified in the mRNAs of these genes. This organization of piRNAs BSs indicates the interdependence of the expression of candidate genes through piRNAs. Significant differences in the ability of genes to interact with piRNAs prevent the side effects of piRNAs on genes with a lack of the ability to bind such piRNAs. Individual piRNAs and sets of piRNAs are proposed and recommended for the diagnosis and therapy of ESCC.

piRNAs may regulate expression of candidate genes of esophageal adenocarcinoma

Elucidation of ways to regulate the expression of candidate cancer genes will contribute to the development of methods for cancer diagnosis and therapy. The aim of the present study was to show the role of piRNAs as efficient regulators of mRNA translation of esophageal adenocarcinoma (EAC) candidate genes. We used bioinformatic methods to study the interaction characteristics of up to 200 thousand piRNAs with mRNAs of 38 candidate EAC genes. The piRNAs capable of binding to mRNA of AR, BTG3, CD55, ERBB3, FKBP5, FOXP1, LEP, SEPP1, SMAD4, and TP53 genes with high free energy by the formation of hydrogen bonds between canonical (G-C, A-U) and noncanonical (G-U, A-C) piRNA and mRNA nucleotide pairs were revealed. The organization of piRNA binding sites (BSs) in the mRNA of candidate genes was found to overlap nucleotide sequences to form clusters. Clusters of piRNA BSs were detected in the 5'-untranslated region, coding domain sequence, and 3'-untranslated region of mRNA. Due to the formation of piRNA binding site clusters, compaction of BSs occurs and competition between piRNAs for binding to mRNA of candidate EAC genes occurs. Associations of piRNA and candidate genes were selected for use as markers for the diagnosis of EAC.

Exosomal noncoding RNAs in colorectal cancer: An overview of functions, challenges, opportunities, and clinical applications

Colorectal cancer (CRC) is the third most threatening malignancy worldwide. Colorectal tumors transfer information with their tumor microenvironment (TME) and communicate together which can be detected through exosome transmission. Exosomes are important regulators made by different types of cells in all body fluids containing RNA, DNA, metabolites, and proteins. Recently, Exosome-derived noncoding RNAs (ncRNAs) applications have gained great consideration based on their potential role in the different pathological processes. Therefore, in this review, we summarized the recent discoveries on exosomal ncRNAs function in CRC initiation and development, and drug resistance to provide a novel insight into exosomal ncRNAs' clinical application and their potential to be biomarkers for CRC patients.

piRNAs and PIWI proteins as potential biomarkers in ‌Breast cancer

BACKGROUND

PIWI interacting RNAs (piRNAs) are another subgroup of small non-coding RNAs, that can play different biological activity further to their capabilities in the germline such as regulating the gene and protein expression, epigenetic silencing of transposable elements, and regulating the spermatogenesis by interacting with PIWI proteins.

METHODS

We search online academic data bases including (Google Scholar, Web of Science and Pub Med), the relevant literature was extracted from the databases by using search terms of piRNAs and breast cancer  as free-text words and also with the combination with OR /AND by may 2022.

RESULTS

Recently, with the help of next-generation sequencing abnormal piRNA expression has been observed to associate with the occurrence and development of human cancers, such as  breast cancer (BC). Recent investigation proposing piRNA as a prognostic and diagnostic biomarker based on their cancer-related interaction in the treatment of BC.

CONCLUSION

This review aims to focus on the role of piRNAs in the initiation, progression, and the occurrence of breast cancer in order to understand its function and provide a better therapeutic strategy.