Long non-coding RNAs PTENP1, GNG12-AS1, MAGI2-AS3 and MEG3 as tumor suppressors in breast cancer and their associations with clinicopathological parameters.

BACKGROUND: Breast cancer is the most commonly occurring cancer worldwide and is the main cause of death from cancer in women. Novel biomarkers are highly warranted for this disease. OBJECTIVE: Evaluation of novel long non-coding RNAs biomarkers for breast cancer. METHODS: The study comprised the analysis of the expression of 71 candidate lncRNAs via screening, six of which (four underexpressed, two overexpressed) were validated and analyzed by qPCR in tumor tissues associated with NST breast carcinomas, compared with the benign samples and with respect to their clinicopathological characteristics. RESULTS: The results indicated the tumor suppressor roles of PTENP1, GNG12-AS1, MEG3 and MAGI2-AS3. Low levels of both PTENP1 and GNG12-AS1 were associated with worsened progression-free and overall survival rates. The reduced expression of GNG12-AS1 was linked to the advanced stage. A higher grade was associated with the lower expression of PTENP1, GNG12-AS1 and MAGI2-AS3. Reduced levels of both MEG3 and PTENP1 were linked to Ki-67 positivity. The NRSN2-AS1 and UCA1 lncRNAs were overexpressed; higher levels of UCA1 were associated with multifocality. CONCLUSIONS: The results suggest that the investigated lncRNAs may play important roles in breast cancer and comprise a potential factor that should be further evaluated in clinical studies.

PTEN regulates expression of its pseudogene in glioblastoma cells in DNA methylation-dependent manner.

Glioblastoma (GBM) is the most aggressive and frequent type of primary brain cancer in adult patients. One of the key molecular features associated with GBM pathogenesis is the dysfunction of PTEN oncosuppressor. In addition to PTEN gene, humans and several primates possess processed PTEN pseudogene (PTENP1) that gives rise to long non-coding RNA lncPTENP1-S. Regulation and functions of PTEN and PTENP1 are highly interconnected, however, the exact molecular mechanism of how these two genes affect each other remains unclear. Here, we analyzed the methylation level of the CpG islands (CpGIs) in the promoter regions of PTEN and PTENP1 in patient-derived GBM neurospheres. We found that increased PTEN methylation corelates with decreased PTEN mRNA level. Unexpectedly, we showed the opposite trend for PTENP1. Using targeted methylation and demethylation of PTENP1 CpGI, we demonstrated that DNA methylation increases lncPTENP1-S expression in the presence of wild type PTEN protein but decreases lncPTENP1-S expression if PTEN protein is absent. Further experiments revealed that PTEN protein binds to PTENP1 promoter region and inhibits lncPTENP1-S expression if its CpGI is demethylated. Interestingly, we did not detect any effect of lncPTENP1-S on the level of PTEN mRNA, indicating that in GBM cells PTENP1 is a downstream target of PTEN rather than its upstream regulator. Finally, we studied the functions of lncPTENP1-S and demonstrated that it plays a pro-oncogenic role in GBM cells by upregulating the expression of cancer stem cell markers and decreasing cell adhesion.

PTEN, PTENP1, microRNAs, and ceRNA Networks: Precision Targeting in Cancer Therapeutics.

The phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a well characterised tumour suppressor, playing a critical role in the maintenance of fundamental cellular processes including cell proliferation, migration, metabolism, and survival. Subtle decreases in cellular levels of PTEN result in the development and progression of cancer, hence there is tight regulation of the expression, activity, and cellular half-life of PTEN at the transcriptional, post-transcriptional, and post-translational levels. PTENP1, the processed pseudogene of PTEN, is an important transcriptional and post-transcriptional regulator of PTEN. PTENP1 expression produces sense and antisense transcripts modulating PTEN expression, in conjunction with miRNAs. Due to the high sequence similarity between PTEN and the PTENP1 sense transcript, the transcripts possess common miRNA binding sites with the potential for PTENP1 to compete for the binding, or 'sponging', of miRNAs that would otherwise target the PTEN transcript. PTENP1 therefore acts as a competitive endogenous RNA (ceRNA), competing with PTEN for the binding of specific miRNAs to alter the abundance of PTEN. Transcription from the antisense strand produces two functionally independent isoforms (PTENP1-AS-α and PTENP1-AS-ß), which can regulate PTEN transcription. In this review, we provide an overview of the post-transcriptional regulation of PTEN through interaction with its pseudogene, the cellular miRNA milieu and operation of the ceRNA network. Furthermore, its importance in maintaining cellular integrity and how disruption of this PTEN-miRNA-PTENP1 axis may lead to cancer but also provide novel therapeutic opportunities, is discussed. Precision targeting of PTENP1-miRNA mediated regulation of PTEN may present as a viable alternative therapy.

Effect of LncRNA PTENP1 on TGF-β-induced Epithelial-mesenchymal Transition in Esophageal Squamous Cell Carcinoma / 肿瘤防治研究

Objective To investigate the role of lncRNA PTENP1 in regulating TGF-β-induced epithelial-mesenchymal transition (EMT) in esophageal squamous cell carcinoma (ESCC). Methods Eca109 and TE-1 cells were treated with TGF-β1, and the expression of PTENP1 was detected by qRT-PCR before and after treatment. PTENP1-overexpressing stably transfected cell lines were constructed in Eca109 and TE-1 cells. The effects of overexpression of PTENP1 on TGF-β1-induced migration, proliferation and EMT-related proteins expression in Eca109 and TE-1 cells were detected by Transwell assay, CCK-8 test and Western blot, respectively. Results The expression of PTENP1 was significantly decreased in Eca109 and TE-1 cells treated with TGF-β1 (P < 0.05). Overexpression of PTENP1 significantly prevented cell migration, decreased the cell vitality, upregulated the E-cadherin expression, and downregulated the expression of N-cadherin and vimentin in Eca109 and TE-1 cells (P < 0.05). Furthermore, PTENP1 overexpression attenuated TGF-β-induced migration of Eca109 and TE-1 cells. PTENP1 overexpression partially reversed TGF-β-induced EMT (P < 0.05). Conclusion PTENP1 plays an important role in TGF-β-induced EMT in ESCC cells.

BMSC-derived exosomal lncRNA PTENP1 suppresses the malignant phenotypes of bladder cancer by upregulating SCARA5 expression.

LncRNAs can be transported to tumor cells where they exert regulatory effects by bone marrow mesenchymal stem cells (BMSC)-derived exosomes. Here, we aimed to investigate the functional mechanism of BMSC-derived exosomal lncRNA PTENP1 in the progression of bladder cancer (BC). Methods of BMSC were identified by detecting surface markers through flow cytometry. Exosomes from BMSC were identified by transmission electron microscopy, nanoparticle tracking analysis (NTA), and western blot analysis of exosome markers. Cellular internalization of BMSC-derived exosomes (BMSC-Exo) into BC cells was detected by confocal microscopy. CCK-8, colony formation, flow cytometry, wound healing, and transwell assays were adopted to estimate cell proliferation, apoptosis, migration, and invasion abilities, respectively. Interplay between miR-17 and lncRNA PTENP1 or SCARA5 was verified by dual-luciferase reporter, RNA pull down, and/or RNA immunoprecipitation (RIP) assays. Tumor xenograft assay was conducted in nude mice to study the role of exosomal lncRNA PTENP1 in BC progression in vivo. We showed exosomal lncRNA PTENP1 can be delivered into and suppress the malignant phenotypes of BC cells. LncRNA PTENP1 was identified as a sponge of miR-17, and SCARA5 was identified as a target gene of miR-17. The exosomes derived from PTENP1-overexpressing BMSC (BMSCOE-PTENP1-Exo) abolished the promotive effects of miR-17 overexpression or SCARA5 knockdown on the malignant phenotypes of BC cells. Moreover, exosomal lncRNA PTENP1 was demonstrated to inhibit BC tumor growth in nude mice by miR-17/SCARA5 axis. In conclusion, BMSC-derived exosomal PTENP1 suppressed the BC progression by upregulating the expression of SCARA5 via sponging miR-17, offering a potential novel therapeutic target for BC therapy.

Early-stage colon cancer with high MALAT1 expression is associated with the 5-Fluorouracil resistance and future metastasis.

BACKGROUND: This study aimed to investigate the role of long noncoding RNA (LncRNA) expression profiles to predict relapse and 5-FU response in patients with stage I/II colon cancer (CC). METHODS AND RESULTS: The expression level of 15 LncRNA was analyzed in stage I/II colon tumors of 126 CC patients. To confirm the findings in-vitro, 5FU-resistant HT29 cells were generated by subjecting HT-29 cells to the increasing concentrations of 5FU for 6 months. The 5FU resistance was observed in WST-1 and Annexin V analyses. The colony formation and wound healing assays were assessed to determine the metastatic properties of the cells. Expression levels of LncRNAs and mRNA of EMT-related genes were determined by RT-PCR. The role of LncRNA on metastasis and 5FU sensitivity were confirmed in pcDNA3.0-PTENP1 and si-MALAT1 expressed 5FU-resistant HT29 cell lineages. RESULTS: High MALAT1 (p = 0.0002) and low PTENP1 (p = 0.0044) expressions were significantly associated with 5-FU resistance and tumor relapse in stage I/II CC. The invasiveness and colony-forming characteristics of 5-FU-resistant cell lineages were higher as compared to the parent HT-29. Moreover, the expression of MALAT1 (p = 0.0009) was increased while the expression of PTENP1 (p = 0.0158) decreased in 5FU-resistant-HT-29 cells. Si-MALAT1 treatment increased cell sensitivity to 5FU, whereas it decreased invasive behaviors of 5 FU-resistant-HT-29 cells. CONCLUSION: MALAT1 may be a biomarker in predicting recurrence in early-stage CC. Our findings suggest that a cell-based therapy to target MALAT1 could be established for these patients to prevent metastasis and 5-FU resistance.

A review on the role of PTENP1 in human disorders with an especial focus on tumor suppressor role of this lncRNA.

PTENP1 is a long non-coding RNA which has been regarded as a pseudogene of the PTEN tumor suppressor gene. However, it has been shown to be a biologically active transcript that can function as a competing endogenous RNA and enhance expression of PTEN protein. This lncRNA has two transcripts, namely PTENP1-202 and PTENP1-202 with sizes of 3996 and 1215 bps, respectively. PTENP1 acts as a sponge for some PETN-targeting miRNAs, such as miR-17, miR-20a, miR-19b, miR-106b, miR-200c, miR-193a-3p, miR-499-5p and miR-214. Besides, it can affect miR-20a/PDCD4, miR-27a-3p/EGR1, miR-17-5p/SOCS6 and miR-19b/TSC1 axes. This long non-coding RNA participates in the pathoetiology of several types of cancers as well as non-malignant conditions such as alcohol-induced osteopenia, insulin resistance, osteoporosis, sepsis-associated cardiac dysfunction and spinal cord injury. In the current review, we elucidate the role of PTENP1 in human disorders, particularly malignant conditions based on evidence acquired from cell line assays, animal studies and investigations on human samples.

Rs7853346 Polymorphism in lncRNA-PTENP1 and rs1799864 Polymorphism in CCR2 are Associated with Radiotherapy-Induced Cognitive Impairment in Subjects with Glioma Via Regulating PTENP1/miR-19b/CCR2 Signaling Pathway.

LncRNA-PTENP1 was reported to promote multiple myeloma cancer stem cell proliferation, and the G allele of rs7853346 polymorphism in lncRNA-PTENP1 was demonstrated to enhance the effect of lncRNA-PTENP1. In this study, we aimed to study the potential effect of lncRNA-PTENP1 and CCR2 mRNA polymorphisms on cognitive impairment in glioma patients. In this study, 279 glioma patients were recruited and grouped according to their genotypes of rs7853346 in PTENP1 and rs1799864 in CCR1. Pathogenic parameters were collected from patients before radiotherapy (month 0) or at month 1 and month 3 after radiotherapy to study the effect of rs7853346 and rs1799864 on cognitive impairment. Sequence analysis, luciferase assay, real-time PCR, and Western blot were performed to study the regulatory relationships between lncRNA-PTENP1, miR-18b, and CCR2. The glioma patient groups exhibited no significant differences concerning basic characteristics. However, the CG&GG/GG genotype alleviated radiotherapy-induced cognitive impairment by exhibiting the highest MMSE among the four groups. On the contrary, parameters including the severity of depression, bladder control, global health status, itchy skin, and weakness of legs all showed no difference among different patient groups at month 0, month 1, and month 3. Also, a long-term positive effect of CG&GG/GG genotype on role functioning and social functioning was also observed after radiotherapy. Compared with patients carrying the CC genotype of rs7853346, the expression of lncRNA-PTENP1 was reduced while the miR-19b level was elevated in patients carrying the CG&GG genotypes of rs7853346. Moreover, the expression of CCR2 mRNA was the highest in the CC/GA&AA group and the lowest in the CG&GG/GG group. Subsequent sequence analysis and luciferase assay indicated that miR-19b could bind to lncRNA-PTENP1 and 3'UTR of CCR2 mRNA, and the knockdown of lncRNA-PTENP1 led to evident up-regulation of miR-19b and down-regulation of CCR2 mRNA/protein in a cellular model, thus verifying the presence of the lncRNA-PTENP1/miR-19b/CCR2 mRNA signaling pathway. In conclusion, by studying the changes in the key parameters of glioma patients who were subjected to radiotherapy, we concluded that the rs7853346 polymorphism in lncRNA-PTENP1 and the rs1799864 polymorphism in CCR2 could independently affect cognitive impairment, while a more significant combined effect on cognitive impairment was exerted in glioma patients via the signaling pathway of PTENP1/miR-19b/CCR2.

Effect of PTENP1 on Proliferation and Apoptosis of Colorectal Cancer Cells and Its Molecular Mechanism / 肿瘤防治研究

Objective To investigate the effect of PTENP1 on the proliferation and apoptosis of colorectal cancer cells and its molecular mechanism. Methods We selected 107 cases of colorectal cancer and corresponding adjacent tissues as the research objects. The expression level of PTENP1 was analyzed by fluorescence quantitative PCR. Colon cancer HT29 cells with PTENP1 overexpression (PTENP1 group) and empty vector cell line (control group) were established by lentivirus. The cell proliferation and apoptosis were analyzed by CCK8 and flow cytometry. The PTENP1 target gene was analyzed by bioinformatics and double luciferase reporter genes. The expression level of target protein was analyzed by Western blot. Results The expression of PTENP1 in colorectal cancer tissues was significantly lower than that in adjacent tissues (P < 0.05). The expression level of PTENP1 in the control group was significantly lower than that in the PTENP1 group (P < 0.05). Compared with the control group, the cell proliferation ability of the PTENP1 group was significantly decreased (P < 0.05), the apoptosis level was significantly increased (P < 0.05). miR-21 was complementary to PTENP1. Compared with the control group, the expression of miR-21 in the PTENP1 group was significantly down-regulated (P < 0.05), and the expression of PTEN protein was significantly up-regulated (P < 0.05). Conclusion PTENP1 and miR-21 competitively bind to regulate the expression of PTEN, and then affect the proliferation and apoptosis of colorectal cancer cells.

Studying the Oncosuppressive Functions of PTENP1 as a ceRNA.

PTENP1 is a processed pseudogene of the tumour suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN). It functions posttranscriptionally to regulate PTEN by acting as a sponge for microRNAs that target PTEN. PTENP1 therefore functions as a competitive endogenous RNA (ceRNA), competing with PTEN for binding of microRNAs (miRNA) and thereby modulating PTEN cellular abundance. Studies of the overexpression of PTENP1 all confirm its oncosuppressive function to be mediated through the suppression of cell proliferation, induction of apoptosis, and inhibition of cell migration and invasion of cancer cells of differing types. These oncosuppressive functions are a direct consequence of miRNA binding by PTENP1 and the subsequent liberation of PTEN from miRNA induced suppression. In this chapter, we will focus initially on the description of a high efficiency transient transfection method to introduce and overexpress PTENP1 in the cell type of interest, followed by accurate methodologies to measure transfection efficiency by flow cytometry. We will then continue to describe two methods to analyze cell proliferation, namely the CCK-8 assay and Click-iT® EdU assay. Due to commonalities in the manifestation of the oncosuppressive effects of PTENP1, mediated through its role as a ceRNA, the methods presented in this chapter will have wide applicability to a variety of different cell types.

Disruption of YY1-EZH2 Interaction Using Synthetic Peptides Inhibits Breast Cancer Development.

Enhancer of zeste homolog 2 (EZH2) is a methyltransferase to mediate lysine 27 trimethylation in histone H3 (i.e., H3K27me3) and repress gene expression. In solid tumors, EZH2 promotes oncogenesis and is considered a therapeutic target. As a transcription factor, Yin Yang 1 (YY1) recruits EZH2 through its oncoprotein binding (OPB) domain to establish gene repression. In this study, we mapped the YY1 protein binding (YPB) domain on EZH2 to a region of 27 amino acids. Both YPB and OPB domain synthetic peptides could disrupt YY1EZH2 interaction, markedly reduce breast cancer cell viability, and efficiently inhibit tumor growth in a xenograft mouse model. We analyzed MDA-MB-231 cells treated with YPB, OPB, and control peptides by chromatin immunoprecipitation DNA sequencing (ChIP-seq) using an antibody against H3K27me3. YPB and OPB treatments altered H3K27me3 on 465 and 1137 genes, respectively, compared to the control. Of these genes, 145 overlapped between the two peptides. Among them, PTENP1, the PTEN pseudogene, showed reduced H3K27me3 signal when treated by either YPB or OPB peptide. Consistently, the two peptides enhanced both PTENP1 and PTEN expression with concomitantly reduced AKT activation. Further studies validated PTENP1's contribution to the anticancer activity of YPB and OPB peptides.

Protective role of matrine in sepsis-associated cardiac dysfunction through regulating the lncRNA PTENP1/miR-106b-5p axis.

BACKGROUND: Matrine has attractive cardioprotective effects in some diseases. This study aimed to evaluate the therapeutic potential of matrine against cardiac dysfunction induced by sepsis in vivo and in vitro, and further explore the related mechanisms. METHODS: Cecal ligation and puncture (CLP) was used to induce a sepsis mice model, and H9C2 cells treated with lipopolysaccharide (LPS) were used as a cardiac myoblast injury model. The evaluation of cardiac function of mice was performed by measuring cardiac function biomarker levels and hemodynamic indicators. An ELISA method was used to examine inflammatory cytokine levels. H9C2 cell viability was measured using MTT assay. The expression of non-coding RNAs that might be involved in matrine function was analyzed using real-time quantitative PCR. RESULTS: Matrine could significantly improve the cardiac function and attenuate the inflammatory response of the mice model, and could increase H9C2 viability and inhibit inflammation in the cell model. By matrine administration, the expression of PTENP1 was downregulated, but miR-106b-5p expression was upregulated both in vivo and in vitro. The cardioprotective effects of matrine in mice and cell models could be reversed by the overexpression of PTENP1 or the knockdown of miR-106b-5p, and the overexpression of miR-106b-5p could significantly abolish the effects of PTENP1 on cardiac function and inflammation. CONCLUSION: All the data revealed that matrine can alleviate sepsis-related cardiac dysfunction by enhancing cardiac myoblast viability and attenuating inflammatory responses through the PTENP1/miR-106b-5p axis.

PTENP1 is a ceRNA for PTEN: it's CRISPR clear.

Here we apply state-of-the-art CRISPR technologies to study the impact that PTENP1 pseudogene transcript has on the expression levels of its parental gene PTEN, and hence on the output of AKT signaling in cancer. Our data expand the repertoire of approaches that can be used to dissect competing endogenous RNA (ceRNA)-based interactions, while providing further experimental evidence in support of the very first one that we discovered.

Pseudogene PTENP1 sponges miR-214 to regulate the expression of PTEN to modulate osteoclast differentiation and attenuate osteoporosis.

BACKGROUND AIMS: Osteoporosis (OP) is a common bone metabolic disease with a high incidence. Our study aimed to explore the pseudogene PTENP1/miR-214/PTEN axis to modulate the osteoclast differentiation in osteoporosis. METHODS: Patients with osteoporosis were recruited in our study, and RANKL-induced osteoclast differentiation and ovariectomy-induced osteoporosis mouse model were established in vitro and in vivo, respectively. RESULTS: Pseudogene PTENP1 and PTEN were significantly down-regulated and miR-214 was up-regulated in osteoporosis patients. In addition, overexpression of PTENP1 or silence of miR-214 inhibited the expression levels of osteoclast specific markers and osteoclast differentiation induced by RANKL. Overexpression of PTENP1 or silence of miR-214 also inhibited the levels of phosphorylation of PI3K and AKT, p65 nuclear translocation, IκBα degradation and the expression level of NFATc1. AlsoSilence of PTENP1 or overexpression of miR-214 induced the osteoclast differentiation under normal physiological condition. Pseudogene PTENP1 sponged miR-214 to regulate the expression of PTEN. CONCLUSIONS: In an ovariectomy-induced osteoporosis mouse model, obvious pathological changes in bone tissues were found, and bone marrow mononuclear cells in this group were more likely to differentiate into osteoclasts. Therefore, pseudogene PTENP1 sponged miR-214 to regulate the expression of PTEN to inhibit osteoclast differentiation and attenuate osteoporosis by suppressing the PI3K/AKT/NF-κB signaling pathway.

LncRNA PTENP1 inhibits cervical cancer progression by suppressing miR-106b.

LncRNA PTENP1 is a competitive endogenous RNA (ceRNA) involved in decoying miR-106b in multiple diseases. This study investigates the interaction of PTENP1 and miR-106b in cell proliferation, apoptosis and epithelial-mesenchymal transition (EMT) in cervical cancer. The expressions of PTENP1, miR-106b and PTEN were determined in cervical cancer tissues, adjacent normal tissues, cervical cancer cells (HeLa, SiHa, C33A and CasKi) and normal cervical epithelial H8 cells. Up-regulation of PTENP1 and down-regulation of miR-106b were conducted in HeLa and CasKi cells by transfecting cells with corresponding miRNA mimics and inhibitors. Bioinformatics analysis, luciferase reporter assay and RNA-pull down assay were performed to verify the association of miR-106b, PTEN, and PTENP1. Cell growth and cell apoptosis were determined by CCK-8 and flow cytometry analysis. It was found that the expressions of PTENP1 and PTEN were up-regulated and that of miR-106b were down-regulated in cervical cancer tissues and cells. PTENP1 localized in cytoplasm and competitively bound to miR-106b. Up-regulation of PTENP1 and down-regulation of miR-106b contributed to increased expressions of PTEN and E-cadherin. Decreased expression of miR-106b, ZEB1, Snail and Vimentin, resulted in inhibiting cell proliferation and promoting cell apoptosis. Over-expression of PTENP1 and miR-106b accelerated cell proliferation and slowed down cell apoptosis. miR-106b inhibited the expression of PTEN. Our results suggest that LncRNA PTENP1 inhibits cervical cancer progression by competitively binding to miR-106b, leading to promote PTEN expression, inhibit cell proliferation and EMT and induce cell apoptosis in cervical cancer cells.

The long noncoding RNA PTENP1 regulates human endometrial epithelial adhesive capacity in vitro: implications in infertility.

There is general consensus that the synchronous development of the embryo and endometrium is absolutely essential for successful implantation. Recent studies have strongly suggested that embryo-secreted factors are able to deliver into the endometrial cavity/endometrium and alter its protein profile in preparation for implantation. However, there is limited research focusing on long noncoding RNA (lncRNA) changes in the endometrium that brought about by the embryonic derived factors. It has been suggested that lncRNA has intricate interplay with microRNA (miR), small (~19-22 nucleotides), non-protein-coding RNA, to regulate protein production in the endometrium, thus controlling adhesive capacity. Here through microarray assays, we compare the lncRNA profile of the primary human endometrial epithelial cells (HEECs) that have been precultured with blastocyst-conditioned media (BCM) from embryos that implanted versus nonimplanted. Our data indicate a substantial change of lncRNA expression in HEECs, including 9 up-regulated and 12 down-regulated lncRNAs after incubation with implanted BCM. Selective knockdown of PTENP1, the most increased lncRNA after implanted BCM treatment in the HEECs, compromised the spheroid adhesion (P < 0.001). Characterization of PTENP1 confirmed its expression in the luminal epithelium with staining appeared most intense in the midsecretory phase. Furthermore, we have recorded a substantial change of miR profile upon PTENP1 knockdown in HEECs. Overexpression of miR-590-3p, a novel predicted target of PTENP1, impaired spheroid adhesion (P < 0.001). Collectively, these data have supported a novel regulation system that lncRNAs were able to participate in the regulation of implantation through association with miRs.

Long noncoding RNA PTENP1 affects the recovery of spinal cord injury by regulating the expression of miR-19b and miR-21.

Exosomes derived from differentiated P12 cells and MSCs were proved to suppress apoptosis of neuron cells, and phosphatase and tensin homolog pseudogene 1 (PTENP1) was reported to inhibit cell proliferation. In this study, we aimed to investigate the role of PTENP1 in the process of post-spinal cord injury (SCI) recovery, so as to evaluate the therapeutic effects of exosomes derived from MSCs transfected with PTENP1 short hairpin RNA (shRNA), as a type of novel biomarkers in the treatment of SCI. Electron microscopy was used to observe the morphology of different exosomes. Real-time polymerase chain reaction and western blot, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays, flow cytometry, Nissl staining, immunohistochemistry assay, and terminal deoxynucleotidyl transferase dUTP nick end labeling assay were conducted to investigate and validate the underlying molecular signaling pathway. PTENP1-shRNA downregulated PTENP1 and PTEN while upregulating miR-21 and miR-19b. PTENP1-shRNA also accelerated cell apoptosis and reduced cell viability. In addition, PTENP1 reduced the miR-21 and miR-19b expression by directly targeting miR-21 and miR-19b. Meanwhile, both miR-21 and miR-19b reduced the expression of PTEN by directly targeting the 3'-untranslated region of PTEN. Furthermore, PTEN level and apoptosis index of neuron cells was the highest in the SCI group, while the treatment with exosomes+PTENP1-shRNA reduced the PTEN expression to a level similar to that in the sham group. Finally, PTENP1 inhibited miR-21 and miR-19b expression but upregulated PTEN expression. The upregulation of miR-21/miR-19b also suppressed the apoptosis of neuron cells by downregulating the PTEN expression. PTENP1 is involved in the recovery of SCI by regulating the expression of miR-19b and miR-21, and exosomes from PTENP1-shRNA-transfected cells may be used as a novel biomarker in SCI treatment.

Expression of PTEN regulated by PTENp1 as a "sponge" adsorbed by miR-21 in oral squamous cell carcinoma / 西安交通大学学报(医学版)

Objective: To explore the role of the new regulator pseudogene phosphatase and tensin homolog pseudogene 1 (PTENp1) in the regulation of PTEN mRNA and gene expression in oral squamous cell carcinoma (OSCC) so as to provide a new target for the prevention, treatment and outcome of OSCC. Methods: First, we collected 42 specimens of OSCC and normal tissues, extracted RNA, detected the expressions of PTENp1, PTEN and miR-21 by qRT-PCR, and studied their correlation by Pearson correlation analysis. HEK293 cells were cultured and transfected with luciferase plasmid of 3'UTR of PTEN and mimic or inhibitor of miR-21 or full-length PTENp1 3'UTR plasmid, respectively. The regulatory role of PTENp1 in PTEN-miR-21 axis and its cancer promoting function were verified by luciferase activity test. Results: qRT-PCR showed that the expressions of PTEN (85.7%) and PTENp1 (90.4%) were significantly repressed in the OSCC tissues while miR-21 expression (76.2%) was remarkably increased. Pearson correlation analysis showed that PTEN expression was negatively correlated with miR-21 expression (R=0.123 5, P<0.001) but positively correlated with PTENp1 expression (R=0.051 8, P=0.01). The results of luciferase activity showed that PTEN expression was significantly up-regulated by overexpression of PTENp1, suggesting that PTENp1 could target competitive binding miR-21 to regulate PTEN expression. Results: PTENp1, as the ceRNA of PTEN, competitively binds the miR-21, which provides a new idea for predicting the early marker and targeting therapy of OSCC in the future.

Exosomal miR-21 regulates the TETs/PTENp1/PTEN pathway to promote hepatocellular carcinoma growth.

BACKGROUND: As an important means of communication, exosomes play an important role in the development of hepatocellular carcinoma (HCC). METHODS: Bioinformatics analysis, dual-luciferase reporter assays, methylation-specific quantitative PCR, and ChIP-PCR analysis were used to gain insight into the underlying mechanism of miR-21 in HCC. RESULTS: The detection of miRNAs in exosomes of HCC showed that miR-21 expression in exosomes was positively correlated with the expression level of miR-21 in cells and negatively correlated with the expression of its target genes PTEN, PTENp1 and TETs. HCC cell-derived exosomes could increase miR-21 and p-Akt expression in HCC cells and downregulate the expression of PTEN, PTENp1 and TETs. MiR-21 inhibitors or PTENp1 overexpression vectors could weaken the effect of the abovementioned exosomes and simultaneously weaken their role in promoting cell proliferation and migration and inhibiting apoptosis. Further studies showed that miR-21 not only directly regulated the expression of PTEN, PTENp1 and TETs but also increased the methylation level of the PTENp1 promoter by regulating the expression of TETs, thereby inhibiting the expression of PTENp1 and further downregulating the expression of PTEN. CONCLUSIONS: Exosomal miR-21 can regulate the expression of the tumor suppressor genes PTEN and PTENp1 in various ways and affect the growth of HCC cells.

G allele of rs7853346 polymorphism in PTENP1 enhances the proliferation of multiple myeloma cancer stem cells by promoting the expression of PTENP1 and its downstream signaling molecules.

Noncoding RNAs, including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), are shown to be associated with the pathogenesis of various diseases, such as multiple myeloma (MM). Therefore, the aim of this study was to explore the role of rs7853346 polymorphism in PTENP1, and its downstream signaling molecules, in the pathology of MM. Forty-three multiple myeloma patients and 35 healthy subjects were recruited and divided into CC, CG, and GG groups according to their genotypes of rs7853346 polymorphism in PTENP1. Real-time polymerase chain reaction (PCR), Western-blot analyses and immunohistochemistry assays were utilized to compare the expression of PTENP1, miR-19b, and TSC1 between different groups. In addition, the relationship between PTENP1, miR-19b, and TSC1, as well as the role of PTENP1 in MM, was explored. Higher levels of PTENP1 and TSC1 mesenger RNA (mRNA) were observed in the MM group, along with a lower level of miR-19b. Moreover, the protein level of TSC1 in the MM group was evidently upregulated compared to that in the negative control (NC) group. Meanwhile, compared to the CG and GG groups, the CC group showed higher levels of PTENP1 and TSC1 mRNA, as well as a lower level of miR-19b. According to the results of real-time PCR, a negative correlation with a correlation coefficient of -0.05 was established between PTENP1 and miR-19b expression. Similarly, a negative correlation with a correlation coefficient of -0.05 was also established between miR-19b and TSC1 expression. In addition, the transfection of pcDNA-PTENP1 or anti-miR-19b into cells significantly suppressed miR-19b expression but obviously increased TSC1 expression. The G allele of rs7853346 polymorphism enhances the proliferation of MM cancer stem cells by promoting the expression of PTENP1 as well as its downstream signaling molecules. Therefore, rs7853346 may become a novel biomarker for the diagnosis and treatment of MM.