P-element-induced Wimpy Testis Research Articles

GASZ is indispensable for gametogenesis in the silkworm, Bombyx mori.

The prominent role of the P-element induced wimpy testis (PIWI)-interacting RNA (piRNA) pathway in animals is to silence transposable elements and maintain genome stability, ensuring proper gametogenesis in gonads. GASZ (Germ cell protein with Ankyrin repeats, Sterile alpha motif, and leucine Zipper) is an evolutionarily conserved protein located on the outer mitochondrial membrane of germ cells and plays vital roles in the piRNA pathway and spermatogenesis in mammals. In the model insect Drosophila melanogaster, GASZ is essential for piRNA biogenesis and oogenesis, whereas its biological functions in non-drosophilid insects are still unknown. Here, we describe a comprehensive investigation of GASZ functions in the silkworm, Bombyx mori, a lepidopteran model insect, by using a binary transgenic CRISPR/Cas9 system. The BmGASZ mutation did not affect growth and development, but led to sterility in both males and females. Eupyrene sperm bundles of mutant males exhibited developmental defects, while the apyrene sperm bundles were normal, which were further confirmed through double copulation experiments with sex-lethal mutants, which males possess functional eupyrene sperm and abnormal apyrene sperm. In female mutant moths, ovarioles were severely degenerated and the eggs in ovarioles were deformed compared with that of wild type (WT). Further RNA-seq and RT-qPCR analysis revealed that amounts of piRNAs and transposon expression were dysregulated in gonads of mutants. In summary, this study has demonstrated vital roles of BmGASZ in gametogenesis through regulating the piRNA pathway in B. mori.

Smartphone-based device for rapid and single-step detection of piRNA–651 using anti-DNA:RNA hybrid antibody and enzymatic signal amplification

P-element-induced wimpy testis (PIWI)-interacting RNAs (piRNAs/piRs) are a class of small noncoding RNAs that play a crucial role in regulating various biological processes, including carcinogenesis. One specific piRNA, piR–651, has been reported to be overexpressed in both human blood serum and solid cancer tissues, that can be used a viable biomarker in cancer diagnosis. Early diagnosis of cancer can help reduce the burden of the disease and improve survival rates. In the present work, we report for the first time a smartphone-based colorimetric biosensor for highly sensitive and specific detection of piR–651 thanks to an enzymatic signal amplification, which yielded high colorimetric intensities. Indeed, a heteroduplex DNA:RNA was formed in the presence of piR–651 with the capture DNA probe immobilized on the magnetic beads for easy magnetic separation. Then, a HRP tethered to anti-DNA:RNA (S9.6) was used to reveal the DNA-RNA heteroduplex formed by catalyzing the oxidation of TMB substrate into colorimetric TMBox, which absorbs at 630 nm. The absorbance is positively proportional to the piR–651 concentrations. On the other hand, the colorimetric product of the assay can be photographed with a smartphone camera and analyzed using ImageJ software. Using a smartphone and under optimal conditions, the biosensor responded linearly to the logarithm of piRNA–651 from 8 fM to 100 pM with a detection limit of 2.3 fM and discriminates against other piRNAs. It was also successfully applied to the determination of piRNA–651 levels in spiked human serum.

Elevated expression patterns of P-element Induced Wimpy Testis (PIWI) transcripts are potential candidate markers for Hepatocellular Carcinoma.

P-Element-induced wimpy testis (PIWI) proteins, when in combination with PIWI-interacting RNA (piRNA), are engaged in the epigenetic regulation of gene expression in germline cells. Different types of tumour cells have been found to exhibit abnormal expression of piRNA, PIWIL-mRNAs, and proteins. We aimed to determine the mRNA expression profiles of PIWIL1, PIWIL2, PIWIL3, & PIWIL4, in hepatocellular carcinoma patients, and to associate their expression patterns with clinicopathological features. The expression patterns of PIWIL1, PIWIL2, PIWIL3, PIWIL4 mRNA, was assessed via real-time quantitative polymerase chain reaction (RT-QPCR), on tissue and serum samples from HCC patients, their impact for diagnosis was evaluated by ROC curves, prognostic utility was determined, and In Silico analysis was conducted for predicted variant detection, association with HCC microRNAs and Network Analysis. Expression levels were significantly higher in both HCC tissue and serum samples than in their respective controls (p< 0.001). Additionally, the diagnostic performance was assessed, Risk determination was found to be statistically significant. PIWIL mRNAs are overexpressed in HCC tissue and serum samples, the expression patterns could be valuable molecular markers for HCC, due to their association with age, tumour grade and pattern. To the best of our knowledge, our study is the first to report the expression levels of all PIWIL mRNA and to suggest their remarkable values as diagnostic and prognostic biomarkers, in addition to their correlation to HCC development. Additionally, a therapeutic opportunity might be also suggested through in silico miRNA prediction for HCC and PIWIL genes through DDX4 and miR-124-3p.

An ingenious double-amplified fluorometric genosensor based on hybridization chain reaction and enzymatic signal for the sensitive detection of piRNA–651

Small noncoding RNAs known as P-element-induced wimpy testis (PIWI)-interacting RNAs (piRNAs/piRs) have attracted significant interest because of their pivotal role in the regulation of various biological processes, including carcinogenesis. Recently, piR–651 has been reported to be overexpressed in human sera and solid cancer tissues, such as breast, gastric, and lung cancers. Early diagnosis can alleviate the cancer burden and reduces the mortality rates. However, conventional detection methods of piRNAs are time-consuming and costly, limiting their clinical applications. In the present work, we report for the first time a fluorometric biosensor for highly sensitive and specific detection of piR–651. An ingenious combination of the target-catalyzed hairpin assembly (CHA) and enzymatic signal amplification yielded a high fluorescence signal. Indeed, the presence of piR–651 triggered the CHA process between biotin-modified hairpin 1 (Bt-H1) and hairpin 2 (H2), leading to the cyclic reuse of piR–651 and producing a large amount of H1–H2 hybrid. The CHA product was captured by a hairpin 3 (H3) immobilized on magnetic beads (MBs) for easy magnetic separation. Streptavidin-Horseradish peroxidase (Sterp-HRP) was used to reveal the CHA product by catalyzing the oxidation of o–phenylenediamine (o–PDA) substrate into fluorescent 2,3–diaminophenazine (DAP), excited at 450 nm and the emission was measured at 570 nm. The fluorescence intensity was found to be positively proportional to the piR-651 concentrations. An experimental design approach was used to optimize the main influential parameters of the bioassay. Under the optimal conditions, the biosensor exhibited a linear response to piR-651 from 5 fM to 200 fM with a detection limit of 0.1 fM, while effectively discriminating other piRs. It was also successfully applied to the determination of piR-651 levels in spiked human serum. Our newly developed fluorometric biosensor offers a highly sensitive and specific detection of piR-651, enabling its potential application in early cancer diagnosis and facilitating the study of its role in various cancer types.

Research progress and potential application of microRNA and other non-coding RNAs in forensic medicine.

At present, epigenetic markers have been extensively studied in various fields and have a high value in forensic medicine due to their unique mode of inheritance, which does not involve DNA sequence alterations. As an epigenetic phenomenon that plays an important role in gene expression, non-coding RNAs (ncRNAs) act as key factors mediating gene silencing, participating in cell division, and regulating immune response and other important biological processes. With the development of molecular biology, genetics, bioinformatics, and next-generation sequencing (NGS) technology, ncRNAs such as microRNA (miRNA), circular RNA (circRNA), long non-coding RNA (lncRNA), and P-element induced wimpy testis (PIWI)-interacting RNA (piRNA) are increasingly been shown to have potential in the practice of forensic medicine. NcRNAs, mainly miRNA, may provide new strategies and methods for the identification of tissues and body fluids, cause-of-death analysis, time-related estimation, age estimation, and the identification of monozygotic twins. In this review, we describe the research progress and application status of ncRNAs, mainly miRNA, and other ncRNAs such as circRNA, lncRNA, and piRNA, in forensic practice, including the identification of tissues and body fluids, cause-of-death analysis, time-related estimation, age estimation, and the identification of monozygotic twins. The close links between ncRNAs and forensic medicine are presented, and their research values and application prospects in forensic medicine are also discussed.

Small non-coding RNA profiling in patients with gastrointestinal cancer.

Small non-coding (snc)RNAs, including microRNAs and P-element induced wimpy testis (PIWI)-interacting-RNAs (piRNAs), crucially regulate gene expression in both physiological and pathological conditions. In particular, some muscle-specific microRNAs (myomiRs) have been involved in the pathogenesis of cancer-induced muscle wasting. The aims of the present study were (i) to profile sncRNAs in both skeletal muscle and plasma of gastrointestinal cancer patients and (ii) to investigate the association among differentially expressed sncRNAs and the level of muscularity at body composition analysis. Surgical patients with gastrointestinal cancer or benign disease were recruited. Blood samples and muscle biopsies (rectus abdominis) were collected during surgery. Low muscularity patients were those at the lowest tertile of skeletal muscle index (SMI; CT-scan), whereas moderate/high muscularity patients were in the middle and highest SMI tertiles. SncRNAs in the muscle were assessed by RNAseq, circulating microRNAs were evaluated by qPCR. Cancer patients (n=25; 13 females, 52%) showed a mean age of 71.6±11.2years, a median body weight loss of 4.2% and a mean BMI of 27.0±3.2kg/m2 . Control group (n=15; 9 females, 60%) showed a mean age 58.1±13.9years and a mean BMI of 28.0±4.3kg/m2 . In cancer patients, the median L3-SMI (cm2 /m2 ) was 42.52 (34.42; 49.07). Males showed a median L3-SMI of 46.08 (41.17-51.79) and females a median L3-SMI of 40.77 (33.73-42.87). Moderate-high and low muscularity groups included 17 and 8 patients, respectively. As for circulating microRNAs, miR-21-5p and miR-133a-3p were up-regulated in patients compared with controls, whereas miR-15b-5p resulted down-regulated in the same comparison (about 30% of control values). Sample clustering by muscularity and sex revealed increased miR-133a-3p and miR-206 only in moderate-high muscularity males. SncRNA profiling in the muscle identified 373 microRNAs and 190 piRNAs (72.5% and 18.7% of raw reads, respectively). As for microRNAs, 10 were up-regulated, and 56 were down-regulated in cancer patients versus controls. Among the 24 dysregulated piRNAs, the majority were down-regulated, including the top two most expressed piRNAs in the muscle (piR-12790 and piR-2106). Network analysis on validated mRNA targets of down-regulated microRNAs revealed miR-15b-5p, miR-106a-5p and miR-106b-5p as main interactors of genes related to ubiquitin ligase/transferase activities. These results show dysregulation of both muscle microRNAs and piRNAs in cancer patients compared with controls, the former following a sex-specific pattern. Changes in circulating microRNAs are associated with the degree of muscularity rather than body weight loss.

PIWI-RNAs Small Noncoding RNAs with Smart Functions: Potential Theranostic Applications in Cancer.

P-element-induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are a new class of small noncoding RNAs (ncRNAs) that bind components of the PIWI protein family. piRNAs are specifically expressed in different human tissues and regulate important signaling pathways. Aberrant expressions of piRNAs and PIWI proteins have been associated with tumorigenesis and cancer progression. Recent studies reported that piRNAs are contained in extracellular vesicles (EVs), nanosized lipid particles, with key roles in cell-cell communication. EVs contain several bioactive molecules, such as proteins, lipids, and nucleic acids, including emerging ncRNAs. EVs are one of the components of liquid biopsy (LB) a non-invasive method for detecting specific molecular biomarkers in liquid samples. LB could become a crucial tool for cancer diagnosis with piRNAs as biomarkers in a precision oncology approach. This review summarizes the current findings on the roles of piRNAs in different cancer types, focusing on potential theranostic applications of piRNAs contained in EVs (EV-piRNAs). Their roles as non-invasive diagnostic and prognostic biomarkers and as new therapeutic options have been also discussed.

A long look at short prokaryotic Argonautes.

Argonaute proteins (Agos) use small 15-30 nucleotide-long guides to bind and/or cleave complementary target nucleic acids. Eukaryotic Agos mediate RNA-guided RNA silencing, while 'long' prokaryotic Agos (pAgos) use RNA or DNA guides to interfere with invading plasmid and viral DNA. Here, we review the function and mechanisms of truncated and highly divergent 'short' pAgos, which, until recently, remained functionally uncharacterized. Short pAgos have retained the Middle (MID) and P-element-Induced Wimpy Testis (PIWI) domains important for guide-mediated target binding, but lack the ability to cleave their targets. Instead, emerging insights reveal that various short pAgos interact with distinct accessory 'effector' enzymes. Upon guide-mediated detection of invading DNA by short pAgos, their associated effector enzymes kill the host cell and, consequentially, prevent spread of the invader.

In vitro study of piwi interaction RNA-31106 promoting breast carcinogenesis by regulating METTL3-mediated m6A RNA methylation.

Breast cancer is the most common gynecological malignancy and the leading cause of cancer-related deaths in women. P-element induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are novel non-coding RNAs whose abnormal expressions have been closely associated with multiple cancers. This study explored the roles and possible mechanisms of piRNA-31106 in breast cancer. The expression of piRNA-31106 in breast cancer tissues and cells was detected by reverse transcription polymerase chain reaction (RT-PCR). The pcDNA vector containing piRNA-31106 (pcDNA-piRNA-31106) and a short hairpin (sh)RNA containing piRNA-31106 (shRNA-piRNA-31106) were used to interfere with piRNA-31106 expression in breast cancer cells. The effects on cell proliferation, apoptosis/cell cycle, invasion, and metastasis were detected via Cell Counting Kit-8 (CCK-8), flow cytometry, transwell assays, and scratch tests, respectively. The protein expressions of murine double minute 2 (MDM2), cyclin-dependent kinase 4 (CDK4), and cyclinD1 were detected by Western blot analysis. The N6-methyladenosine (m6A) RNA methylation level and the binding relationship between piRNA-31106 and METTL3 were analyzed. The role of METTL3 in the regulation of breast cancer by piRNA-31106 was further analyzed by using small interfering (si)RNA targeting METTL3. PiRNA-31106 was highly expressed in breast cancer tissues and cell lines MDA-MB-231 and MCF-7. Overexpression of piRNA-31106 promoted the viability, invasion, and migration of breast cancer, inhibited apoptosis, and promoted the expressions of MDM2, CDK4, and cyclinD1. Inhibition of piRNA-31106 showed the opposite effect. In addition, piRNA-31106 promoted the m6A methylation levels and facilitated methyltransferase-like 3 (METTL3) expression in MDA-MB-231 and MCF-7 cells. RNA immunoprecipitation (RIP) assays confirmed the binding relationship between piRNA-31106 and METTL3. Further experiments demonstrated that si-METTL3 could inhibit the regulatory effects of piRNA-31106 on breast cancer. PiRNA-31106 was significantly highly expressed in breast cancer and could promote breast cancer progression by regulating METTL3-mediated m6A RNA methylation.

Serum Exosome-Derived piRNAs Could Be Promising Biomarkers for HCC Diagnosis.

Serum exosome-based liquid biopsy has significant advantages for screening and diagnosing hepatocellular carcinoma (HCC). P-element-induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are novel small silencing RNAs that have been identified to function in cancer-related signalling pathways. However, studies on the presence of piRNAs in serum exosomes from HCC patients and their diagnostic values in HCC are not well reported. Our aim is to validate serum exosome-derived piRNAs as the valuable component of liquid biopsy for diagnosing HCC. We used small RNA (sRNA) sequencing to profile piRNAs from serum exosomes and describe the base distribution characteristics of serum exosome-derived piRNAs. Serum exosomes from 125 HCC patients and 44 nontumor donors were included in this study. We found that piRNAs were components of serum exosomes from HCC patients. A total of 253 differentially expressed serum exosome-derived piRNAs were screened from HCC compared with the piRNAs from nontumor donors. Serum exosome-derived piRNAs from HCC displayed a distinctive base distribution. To further confirm the potential diagnostic value of serum exosome-derived piRNAs in HCC, we detected the levels of the top 5 upregulated piRNAs in our Chinese cohort. The training set and validation set both showed that all 5 piRNAs were dramatically increased in the serum exosomes from HCC compared with the piRNAs from non-tumour donors. The piRNAs could strongly identify HCC patients from non-tumour donors according to the area under the receiver operating characteristic (AUROC) model. Additionally, the piRNAs could also present significant values for the diagnosis of HCC with low tumour burden. piRNAs enriched the components of serum exosomes from HCC and could serve as promising biomarkers for HCC diagnosis.

Piwi-Interacting RNAs As Diagnostic and Prognostic Biomarker in Cancer: A Pooling Analysis of Retrospective Studies

Background: P-element induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are the most mysterious class of small non-coding RNAs. They limit gene expression in gonads and sequence diversity. Dysregulated piRNAs can led to all kinds of cancers. Recently, piRNAs were postulated to be potentially useful biomarkers for tumor diagnosis and prognosis. However, there lack a systematic review of prognostic and diagnostic piRNAs in neoplasms. The study aimed to decipher the relationships between piRNAs expression, diagnostic and prognostic outcome in tumors. Methods: This study systematically searched Google Scholar, MEDLINE, Scopus, PubMed, Embase, ScienceDirect, Ovid-Medline, Chinese National Knowledge Infrastructure, WanFang and SinoMed databases for relevant articles published before July 13, 2022. The study is registered in PROSPERO (CRD42020208717). Results: Thirty relevant studies were included in the meta-analysis: 19 on diagnosis and 23 on prognosis. The pooled adds ratio, 95% confidence intervals (Cl) and hazard ratios (HR) of the studies were used to investigate the clinical parameters and overall survival (OS) of cancer patients. The area under the curve (AUC), sensitivity, and specificity was 0.82, 79%, and 77% in tumors, respectively. Though abnormally expressed piRNAs were associated with poor and unfavorable impacts on the OS time of cancer patients (HR=1.00, 95% Cl: 1.00-1.00, P&lt;0.00001). Meanwhile, piRNAs in the breast cancer had favorable impacts on the OS (HR=0.70, 95% CI:0.45-1.09). However, the piRNAs in cell renal cell carcinoma, colorectal cancer, diffuse large B-cell lymphoma and gastric cancer had bad favorable impacts on the OS (HR=1.46, 95% CI:1.37-1.55; HR=1.56, 95% CI:1.24 -1.95; HR=2.19, 95% CI:1.25-3.86; HR=1.01, 95% CI:0.97-1.04, respectively). Conclusions: The results strongly suggested that piRNAs were potential novel prognostic and diagnostic indicators in tumors.

P-Element-Induced Wimpy Testis Proteins and P-Element-Induced Wimpy Testis-Interacting RNAs Expression in Ovarian Cancer Stem Cells.

Background: P-element-induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are a type of noncoding RNA and are predominantly expressed in germline cells. piRNAs function as gene regulators and potential biomarkers for the development of a number of malignancies. The biological importance of piRNAs in ovarian cancer is still unknown. In this study, we investigated the expression of piRNAs in ovarian cancer stem cells and compared it with that in adherent cells. Methods: To assess changes in the expression levels of PIWIL1/HIWI, PIWIL2/HILI, PIWIL3, and PIWIL4/HIWI2, we used quantitative reverse-transcription polymerase chain reaction (RT-qPCR) analysis. Changes in piRNA expression levels in ovarian cancer stem cells were analyzed using Arraystar piRNA microarray screening. Gene Ontology (GO) enrichment analysis was conducted to determine the potential functions of piRNAs. Results: Using microarray analysis, we identified a cohort of differentially expressed piRNAs. Fifteen piRNAs, including DQ570763 and DQ597396, were downregulated, and 58 piRNAs were upregulated when compared with those in adherent A2780 and SKOV3 cells (p > 0.05, >2.0, respectively). GO functions of the downregulated piRNAs (DQ570763 and DQ570797) suggest that their roles are commonly associated with the Golgi apparatus. In addition, A2780-SP and SKOV3-SP cells had higher PIWIL3 and PIWIL4 mRNA levels than adherent cells (A2780 and SKOV3). Moreover, we determined, using receiver operating characteristic plot, that the expression level of PIWIL4 was lower in responders than in nonresponders after treatment with platins in patients with ovarian cancer. Finally, in ovarian cancer, PIWIL4 expression was associated with somatic mutations of dynein axonemal heavy chain 2, signal induced proliferation associated 1 like 2, YTH N6-methyladenosine RNA-binding protein 1, TBC1 domain family member 8, and LPS responsive Beige-like anchor protein. Conclusion: Our study showed that PIWI proteins and piRNAs are potential diagnostic and prognostic biomarkers for ovarian cancer.

Emerging roles and potential application of PIWI-interacting RNA in urological tumors.

The piRNA (PIWI-interacting RNA) is P-Element induced wimpy testis (PIWI)-interacting RNA which is a small molecule, non-coding RNA with a length of 24-32nt. It was originally found in germ cells and is considered a regulator of germ cell function. It can interact with PIWI protein, a member of the Argonaute family, and play a role in the regulation of gene transcription and epigenetic silencing of transposable factors in the nucleus. More and more studies have shown that piRNAs are abnormally expressed in a variety of cancer tissues and patient fluids, and may become diagnostic tools, therapeutic targets, staging markers, and prognostic evaluation tools for cancer. This article reviews the recent research on piRNA and summarizes the structural characteristics, production mechanism, applications, and its role in urological tumors, to provide a reference value for piRNA to regulate urological tumors.

Mechanism of piR-1245/PIWI-like protein-2 regulating Janus kinase-2/signal transducer and activator of transcription-3/vascular endothelial growth factor signaling pathway in retinal neovascularization.

Inhibiting retinal neovascularization is the optimal strategy for the treatment of retina-related diseases, but there is currently no effective treatment for retinal neovascularization. P-element-induced wimpy testis (PIWI)-interacting RNA (piRNA) is a type of small non-coding RNA implicated in a variety of diseases. In this study, we found that the expression of piR-1245 and the interacting protein PIWIL2 were remarkably increased in human retinal endothelial cells cultured in a hypoxic environment, and cell apoptosis, migration, tube formation and proliferation were remarkably enhanced in these cells. Knocking down piR-1245 inhibited the above phenomena. After intervention by a p-JAK2 activator, piR-1245 decreased the expression of hypoxia inducible factor-1α and vascular endothelial growth factor through the JAK2/STAT3 pathway. For in vivo analysis, 7-day-old newborn mice were raised in 75 ± 2% hyperoxia for 5 days and then piR-1245 in the retina was knocked down. In these mice, the number of newly formed vessels in the retina was decreased, the expressions of inflammation-related proteins were reduced, the number of apoptotic cells in the retina was decreased, the JAK2/STAT3 pathway was inhibited, and the expressions of hypoxia inducible factor-1α and vascular endothelial growth factor were decreased. Injection of the JAK2 inhibitor JAK2/TYK2-IN-1 into the vitreous cavity inhibited retinal neovascularization in mice and reduced expression of hypoxia inducible factor-1α and vascular endothelial growth factor. These findings suggest that piR-1245 activates the JAK2/STAT3 pathway, regulates the expression of hypoxia inducible factor-1α and vascular endothelial growth factor, and promotes retinal neovascularization. Therefore, piR-1245 may be a new therapeutic target for retinal neovascularization.

A Novel PiRNA Enhances CA19-9 Sensitivity for Pancreatic Cancer Identification by Liquid Biopsy.

Pancreatic cancer is one of the deadliest tumours worldwide, and its poor prognosis is due to an inability to detect the disease at the early stages, thereby creating an urgent need to develop non-invasive biomarkers. P-element-induced wimpy testis (PIWI) proteins work together with piwi-interacting RNAs (piRNAs) to perform epigenetic regulation and as such hold great potential as biomarkers for pancreatic cancer. PIWIL2 and PIWIL4 are associated with better prognosis, while PIWIL1 and PIWIL3 involvement appears to be associated with carcinogenesis. We aimed to discover PIWIL3- and PIWIL4-modulated piRNAs and determine their potential mechanisms in pancreatic cancer and the clinical implications. PIWIL3 or PIWIL4 was downregulated in pancreatic cancer-derived cell lines or in a non-tumour cell line. Differentially expressed piRNAs were analysed by next generation sequencing of small RNA. Nine fresh-frozen samples from solid human pancreases (three healthy pancreases, three intraductal papillary mucinous neoplasms, and three early-stage pancreatic cancers) were included in the sequencing analysis. Two piRNAs associated with PIWIL3 (piR-168112 and piR-162725) were identified in the neoplastic cells; in untransformed samples, we identified one piRNA associated with PIWIL4 (pir-366845). After validation in pancreatic cancer-derived cell lines and one untransformed pancreatic cell line, these piRNAs were evaluated in plasma samples from healthy donors (n = 27) or patients with pancreatic cancer (n = 45). Interestingly, piR-162725 expression identified pancreatic cancer patients versus healthy donors in liquid biopsies. Moreover, the potential of the serum carbohydrate antigen 19-9 (CA19-9) biomarker to identify pancreatic cancer patients was greatly enhanced when combined with piR-162725 detection. The enhanced diagnostic potential for the early detection of pancreatic cancer in liquid biopsies of these new small non-coding RNAs will likely improve the prognosis and management of this deadly cancer.

P-element-Induced Wimpy-Testis-Like Protein 1 Regulates the Activation of Pancreatic Stellate Cells Through the PI3K/AKT/mTOR Signaling Pathway.

Pancreatic fibrosis is the main pathological characteristic of chronic pancreatitis (CP) and pancreatic cancer. Pancreatic stellate cells (PSCs) play a critical role in pancreatic fibrosis. Any targets that may have an impact on the activation of PSCs could become potential treatment candidates for CP and pancreatic cancer. Our goal was to investigate the effect of P-element-induced wimpy-testis (PIWI) protein 1 (PIWIL1) on PSC activation. Lentivirus-based RNA interference (RNAi) and overexpression vector construction were used to knock down and over-express the PIWIL1 protein. Immunocytofluorescent staining, western blotting, wound healing assay, transwell assay, and phalloidin staining were used to investigate the effects of PIWIL1 on the secretion of extracellular matrix components (EMC), actin cytoskeleton, and on the invasion and migration abilities of primary PSCs isolated from C57BL/6 mice. Moreover, pancreatic fibrosis was induced by L-arginine in C57BL/6 mice. The expression of PIWIL1 and collagen deposition in vivo were tested by western blotting and Sirius red staining. Expression levels of collagen I, collagen III, and α-smooth muscle actin were significantly decreased in the LV-PIWIL1 group. Compared with the si-PIWIL1 group, significant differences were observed in the expression of desmin, p-PI3K, p-AKT, and p-mTOR in the LV-PIWIL1 group. Furthermore, PIWIL1 suppressed the PSCs' invasion and migration abilities. In a rescue experiment, the PI3K/AKT/mTOR signaling pathway was found to be the underlying mechanism in PSCs activation mediated by PIWIL1. Our findings suggest that PIWIL1 inhibits the activation of PSCs via the PI3K/AKT/mTOR signaling pathway. PIWIL1 is a potential therapeutic target for pancreatic fibrosis.

Aberrantly Expressed Small Noncoding RNAome in Keloid Skin Tissue.

The skin is an organ that protects against injury and infection but can be damaged easily. Wound healing is a subtle balance which, if broken, can lead to keloid formation. Small noncoding (nc) RNAs can be of “housekeeping,” for example, ribosomal RNAs and transfer RNAs, or “regulatory,” for example, microRNAs (miRNAs or miRs), small nucleolar RNAs (snoRNAs), and P-element–induced Wimpy testis (PIWI)-interacting RNA (piRNA) types. We examined five types of small ncRNAs [miR, piRNA, snoRNA, small nuclear (sn) RNA, and repeat-associated small interfering RNA (rasiRNA)] in keloid skin tissue (KST) using sequencing and real-time reverse transcription-quantitative polymerase chain reaction. All comparisons were made in relation to expression in normal skin tissue (obtained by abdominoplasty). The expression of three piRNAs was upregulated, and the expression of six piRNAs was downregulated in KST. The expression of 12 snoRNAs was upregulated, and the expression of two snoRNAs was downregulated in KST. The expression of two snRNAs was downregulated in KST. The expression of 18 miRs was upregulated, and the expression of three miRNAs was downregulated in KST. The expression of one rasiRNA was upregulated, and the expression of one rasiRNA was downregulated in KST. We revealed the differential expression of small ncRNAs in KST, which may aid the development of new treatment for keloids.

PIWI-interacting RNA (piRNA): a narrative review of its biogenesis, function, and emerging role in lung cancer.

Cancer remains elusive in many aspects, especially in its causes and control. After protein profiling, genetic screening, and mutation studies, scientists now have turned their attention to epigenetic modulation. This new arena has brought to light the world of noncoding RNA (ncRNA). Although very complicated and often confusing, ncRNA domains are now among the most attractive molecular markers for epigenetic control of cancer. Long ncRNA and microRNA (miRNA) have been studied best among the noncoding genome and huge data have accumulated regarding their inhibitory and promoting effects in cancer. Another sector of ncRNAs is the world of PIWI-interacting RNAs (piRNAs). Initially discovered with the asymmetric division of germline stem cells in the Drosophila ovary, piRNAs have a unique capability to associate with mammalian proteins analogous to P-element induced wimpy testis (PIWI) in Drosophila and are capable of silencing transposons. After a brief introduction to its discovery timelines, the present narrative review covers the biogenesis, function, and role of piRNAs in lung cancer. The effects on lung cancer are highlighted under sections of cell proliferation, stemness maintenance, metastasis, and overall survival, and the review concludes with a discussion of recent discoveries of another class of small ncRNAs, the piRNA-like RNAs (piR-Ls).

Elevated P-Element-Induced Wimpy-Testis-Like Protein 1 Expression Predicts Unfavorable Prognosis for Patients with Various Cancers.

Increasing evidence has shown that overexpression of P-element-induced wimpy-testis (PIWI)-like protein 1 (PIWIL1) was associated with unfavorable prognosis of patients with various types of cancers. Herein, we conducted this meta-analysis to identify the clinicopathological and prognostic value of the PIWIL1 expression in cancers. Three electronic databases (PubMed, Web of Science, and Embase) were comprehensively retrieved for relevant studies up to August 4th, 2019. RevMan 5.3 and STATA 12.0 statistical software programs were used to explore the relationships between PIWIL1 expression and the prognosis and clinicopathological features in cancer patients. A total of 13 studies recruiting 2179 patients with 9 types of solid tumors were finally included in the meta-analysis. The results indicated that patients with high PIWIL1 expression tended to have a shorter survival, and additionally deeper tumor invasion, higher clinical stage, and more lymph node metastasis. PIWIL1 could serve as a biomarker for prognosis and clinicopathological characteristics in various cancers.

Investigation of the expression of P-element-induced wimpy testis-interacting RNAs in human acute myeloid leukemia

P-element induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are a newly known class of small non-coding RNAs with 24–31 nucleotides in length. There are more than 20,000 piRNA genes in the human genome and some of them have a role in cancer. In this study, we investigated the expression of piRNAs in acute myeloid leukemia (AML). We used publicly available small RNA sequencing data derived from the peripheral blood of patients with AML and control samples to be re-analyzed for investigation of piRNA expression pattern and then was validated via the real-time polymerase chain reaction (PCR). Differential expression analysis showed that four upregulated piRNAs and six downregulated piRNAs in AML samples, among which, the piR-32,877 and piR-33,195 were the top two upregulated piRNAs. Real-time PCR was performed to validate the increased expression of these two piRNAs in AML compared to controls. Pathway analysis was also performed. The results provide evidence that piR-32,877 and piR-33,195 may serve as a new diagnostic and prognostic biomarker in AML.