Tumor suppressive activity of PIWI‐interacting RNA in human fibrosarcoma mediated through repression of RRM2

Abstract

P‐element induced wimpy testis (PIWI)‐interacting RNAs (piRNAs) are a promising class of small regulatory RNAs, earlier believed to control transposable elements (TEs) activity in germlines are now reported in somatic and cancer cells. The aberrant expression of piRNAs has been documented in various cancers wherein they modulate tumorigenesis either as oncogenes or tumor suppressors by curbing target gene expression. However, there is no report yet on the association of piRNAs in fibrosarcoma, an early metastatic lethal tumor. For the first time, we reported a piRNA, piR‐39980 in fibrosarcoma and investigated its potential role in malignancy by employing several methods such as qRT‐PCR, MTT assay, transwell invasion and migration assay, wound healing assay, flow cytometric cell cycle analysis, Annexin V‐PE apoptosis assay, AO/EB dual staining assay, and chromatin condensation assay. We observed that piR‐39980 significantly attenuated proliferation, migration, invasion, and colony forming ability as well as induced apoptotic cell death of HT1080 fibrosarcoma cells when transiently overexpressed with its piRNA mimics. The dual luciferase reporter assay confirmed that piR‐39980 promotes apoptosis and inhibits proliferation in fibrosarcoma by repressing RRM2 through direct targeting at its 3′UTR through extensive sequence complementary binding, unlike microRNA targeting. In summary, this study revealed that piR‐39980 has a strong anti‐tumor effect and hence could be a promising RNA‐based therapeutic agent for the malignancy of fibrosarcoma.

piR‐39980 promotes cell proliferation, migration and invasion, and inhibits apoptosis via repression of SERPINB1 in human osteosarcoma

“…Notably, our previous study has revealed that piR‐39980 is downregulated in fibrosarcoma cells and acts as a tumour suppressor in fibrosarcoma by targeting Ribonucleoside‐diphosphate reductase subunit M2 (RRM2) [Das et al., ], whereas current study revealed an opposite role for the piRNA as an oncogene in OS by targeting SERBINB1. To ensure its cancer‐type specific differential role, we checked the expression of RRM2 in OS cell lines by qRT‐PCR upon transfection with 80 nM piR‐39980 mimic and inhibitor.…”

mRNA and P-element-induced wimpy testis-interacting RNA profile in chemical-induced oral squamous cell carcinoma mice model

“…piR-55490 plays an inhibitory role in lung cancer by targeting mTOR signaling [24]. piR-39980 plays an inhibitory role in fibrosarcoma by repressing RRM2 [9]. However, the piRNAs expression profile in OSCC has not been investigated yet.…”

“…piR-39980 exhibits anti-tumor effects in fibrosarcoma by repressing ribonucleotide reductase M2 subunit (RRM2) through direct binding at its 3'-untranslated region (UTR). However, this interaction is extensively complementary, which is different from the seed binding of microRNAs [9]. However, the expression profile of piRNAs in OSCC and their role in OSCC development and progression has not been investigated yet.…”

Restoration of microRNA‐197 expression suppresses oncogenicity in fibrosarcoma through negative regulation of RAN

“…All the reactions (miRNA and mRNA) were performed in triplicates and expression levels were calculated in terms of Relative normalized expression. The detailed protocol is provided in our previous study …”

“…The detailed protocol is provided in our previous study. 22 2.3 | Synthetic RNA oligonucleotides and transient transfection miR-197-3p mimic and scramble were purchased from Qiagen as RNA oligo. The 3´UTR of RAN (Gene ID: 5901) with miR-197-3p binding sites (GUGGUGAA) (wild-type, WT) and mutant (MUT) with four nts mutation (GGUGGUAA) were cloned into psiCHECK-2 vector (a gift from Dr. Beena Pillai, IGIB, New Delhi) having both firefly luciferase and Renilla luciferase.…”