PIWI-interacting RNAs (piRNA) suppress selfish genetic elements and are essential for germ cell biology in animals. They also play critical roles in regeneration in planaria, regulate gene expression in adult mammalian testes, and participate in antiviral defense in mosquitoes. Inspired by a recent workshop on PIWI proteins and piRNAs, this commentary aims to summarize fundamental aspects of piRNA biology, highlight recent advances, and discuss key outstanding questions. It is written by and for biochemists, geneticists, and evolutionary biologists, and represents our interdisciplinary perspective.

This commentary highlights, from an interdisciplinary perspective, recent advances and key outstanding questions in the field of piRNA biology. [Image: see text]

• Publikační typ
• časopisecké články MeSH

PIWI-interacting RNAs (piRNAs) play a crucial role in safeguarding genome integrity by silencing mobile genetic elements. From flies to humans, piRNAs originate from long single-stranded precursors encoded by genomic piRNA clusters. How piRNA clusters form to adapt to genomic invaders and evolve to maintain protection remain key outstanding questions. Here, we generate a roadmap of piRNA clusters across seven species that highlights both similarities and variations. In mammals, we identify transcriptional readthrough as a mechanism to generate piRNAs from transposon insertions (piCs) downstream of genes (DoG). Together with the well-known stress-dependent DoG transcripts, our findings suggest a molecular mechanism for the formation of piRNA clusters in response to retroviral invasion. Finally, we identify a class of dynamic piRNA clusters in humans, underscoring unique features of human germ cell biology. Our results advance the understanding of conserved principles and species-specific variations in piRNA biology and provide tools for future studies.

• Klíčová slova
• CP: Molecular biology, PIWI, evolution, fertility, germ cell, mobile genetic element, piRNA, readthrough transcription, spermatogenesis, stress, transposon,
• MeSH
• druhová specificita MeSH
• lidé MeSH
• malá interferující RNA * metabolismus   genetika   MeSH
• myši MeSH
• Piwi-interagující RNA MeSH
• psi MeSH
• savci * genetika   MeSH
• transpozibilní elementy DNA genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, N.I.H., Intramural MeSH
• srovnávací studie MeSH
• Názvy látek
• malá interferující RNA * MeSH
• Piwi-interagující RNA MeSH
• transpozibilní elementy DNA MeSH

Small noncoding RNAs play an important role in various disease states, including cancer. PIWI proteins, a subfamily of Argonaute proteins, and PIWI-interacting RNAs (piRNAs) were originally described as germline-specific molecules that inhibit the deleterious activity of transposable elements. However, several studies have suggested a role for the piRNA-PIWI axis in somatic cells, including somatic stem cells. Dysregulated expression of piRNAs and PIWI proteins in human tumors implies that, analogously to their roles in undifferentiated cells under physiological conditions, these molecules may be important for cancer stem cells and thus contribute to cancer progression. We provide an overview of piRNA biogenesis and critically review the evidence for the role of piRNA-PIWI axis in cancer stem cells. In addition, we examine the potential of piRNAs and PIWI proteins to become biomarkers in cancer.

• Klíčová slova
• Cancer, Cancer stem cells, PIWI proteins, PIWI-interacting RNAs, piRNAs,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH