Tensin Homolog Expression Research Articles

Gnetin C Intercepts MTA1-Associated Neoplastic Progression in Prostate Cancer.

Nutritional chemoprevention is particularly suitable for prostate cancer. Gnetin C, a resveratrol dimer found abundantly in the melinjo plant (Gnetum gnemon), may possess more potent biological properties compared to other stilbenes. We examined the effects of gnetin C in a high-risk premalignant transgenic mouse model overexpressing tumor-promoting metastasis-associated protein 1 (MTA1) on the background of Pten heterozygosity (R26MTA1; Pten+/f; Pb-Cre+). Mice were fed diets supplemented with the following compounds: pterostilbene (70 mg/kg diet); gnetin C, high dose (70 mg/kg diet); and gnetin C, low dose (35 mg/kg diet). Prostate tissues were isolated after 17 weeks and examined for histopathology and molecular markers. Serum was analyzed for cytokine expression. Gnetin C-supplemented diets substantially delayed the progression of preneoplastic lesions compared to other groups. Prostate tissues from gnetin C-fed mice showed favorable histopathology, with decreased severity and number of prostatic intraepithelial neoplasia (PIN) foci, reduced proliferation, and angiogenesis. A decreased level of MTA1, concurrent with the trend of increasing phosphatase and tensin homolog expression and reduced interleukin 2 (IL-2) levels in sera, were also detected in gnetin C-fed mice. Importantly, gnetin C did not exert any visible toxicity in mice. Our findings demonstrate that a gnetin C-supplemented diet effectively blocks MTA1-promoted tumor progression activity in high-risk premalignant prostate cancer, which indicates its potential as a novel form of nutritional interception for prostate cancer chemoprevention.

Therapeutic Potential of 6-Gingerol in Prevention of Colon Cancer Induced by Azoxymethane through the Modulation of Antioxidant Potential and Inflammation.

A polyphenolic component of ginger, 6-gingerol, is widely reported to possess antioxidant, anti-inflammatory and anticancer activities. In the current study, it was aimed to investigate the anticancer effects of 6-gingerol (6-Gin) on azoxymethane (AOM)-induced colon cancer in rats. The results reveal that 6-Gin treatment significantly improves the antioxidant status disturbed by AOM intoxication. The 6-Gin treatment animal group showed enhanced activity of catalase (CAT) (46.6 ± 6.4 vs. 23.3 ± 4.3 U/mg protein), superoxide dismutase (SOD) (81.3 ± 7.6 vs. 60.4 ± 3.5 U/mg protein) and glutathione-S-transferase (GST) (90.3 ± 9.4 vs. 53.8 ± 10 mU/mg protein) (p < 0.05) as compared to the disease control group. Furthermore, the results reveal that AOM significantly enhances the inflammatory response and 6-gingerol potentially attenuates this response, estimated by markers, such as tumor necrosis factor-α (TNF-α) (1346 ± 67 vs. 1023 ± 58 pg/g), C-reactive protein (CRP) (1.12 ± 0.08 vs. 0.92 ± 0.7 ng/mL) and interleukin-6 (IL-6) (945 ± 67 vs. 653 ± 33 pg/g). In addition, the lipid peroxidation estimated in terms of malondialdehyde (MDA) provoked by AOM exposure is significantly reduced by 6-gingerol treatment (167 ± 7.5 vs. 128.3 nmol/g). Furthermore, 6-gingerol significantly maintains the colon tissue architecture disturbed by the AOM treatment. Loss of tumor suppressor protein, phosphatase and tensin homolog (PTEN) expression was noticed in the AOM treated group, whereas in the animals treated with 6-gingerol, the positivity of PTEN expression was high. In conclusion, the current findings advocate the health-promoting effects of 6-gingerol on colon cancer, which might be due to its antioxidant and anti-inflammatory potential.

LncNALT knockdown ameliorates hypertensive retinopathy via PTEN/PI3K/AKT pathway

ABSTRACT This study aimed to explore the role of the long non-coding RNA NOTCH1-associated lncRNA in T cell acute lymphoblastic leukemia (lncNALT) in the pathogenesis of hypertensive retinopathy (HR). LncNALT expression levels were determined using reverse transcription-quantitative polymerase chain reaction. The effects of lncNALT knockdown on the viability, proliferation, migration, and invasion of human retinal microvascular endothelial cells (RMECs) were determined via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, 5-ethynyl-2’-deoxyuridine staining, and Transwell assays. Protein expression levels were determined using western blotting. We found that lncNALT expression levels were increased in RMECs treated with hydrogen peroxide (H2O2), while the knockdown of lncNALT rescued the viability, proliferation, migration, and invasion of RMECs treated with H2O2. Moreover, lncNALT interacted with ELAV like RNA binding protein 1 to affect the phosphatase and tensin homolog (PTEN) expression. Knockdown of lncNALT enhanced the viability, proliferation, migration, and invasion of RMECs via the PTEN/phosphoinositide 3-kinase (PI3K)/serine-threonine kinase (AKT) pathway. Taken together, knockdown of lncNALT enhanced the viability, proliferation, migration, and invasion of RMECs via the PTEN/PI3K/AKT pathway, suggesting that lncNALT could be a potential therapeutic target for patients with HR.

PARK7 deficiency inhibits fatty acid β-oxidation via PTEN to delay liver regeneration after hepatectomy.

Background & aimsTransient regeneration–associated steatosis (TRAS) is a process of temporary hepatic lipid accumulation and is essential for liver regeneration by providing energy generated from fatty acid β‐oxidation, but the regulatory mechanism underlying TRAS remains unknown. Parkinsonism‐associated deglycase (Park7)/Dj1 is an important regulator involved in various liver diseases. In nonalcoholic fatty liver diseased mice, induced by a high‐fat diet, Park7 deficiency improves hepatic steatosis, but its role in liver regeneration remains unknownMethods Park7 knockout (Park7 −/−), hepatocyte‐specific Park7 knockout (Park7 △hep) and hepatocyte‐specific Park7‐Pten double knockout mice were subjected to 2/3 partial hepatectomy (PHx)ResultsIncreased PARK7 expression was observed in the regenerating liver of mice at 36 and 48 h after PHx. Park7 −/− and Park7 △hep mice showed delayed liver regeneration and enhanced TRAS after PHx. PPARa, a key regulator of β‐oxidation, and carnitine palmitoyltransferase 1a (CPT1a), a rate‐limiting enzyme of β‐oxidation, had substantially decreased expression in the regenerating liver of Park7 △hep mice. Increased phosphatase and tensin homolog (PTEN) expression was observed in the liver of Park7 △hep mice, which might contribute to delayed liver regeneration in these mice because genomic depletion or pharmacological inhibition of PTEN restored the delayed liver regeneration by reversing the downregulation of PPARa and CPT1a and in turn accelerating the utilization of TRAS in the regenerating liver of Park7 △hep miceConclusion Park7/Dj1 is a novel regulator of PTEN‐dependent fatty acid β‐oxidation, and increasing Park7 expression might be a promising strategy to promote liver regeneration.

Angiotensin II prompts heart cell apoptosis via AT1 receptor-augmented phosphatase and tensin homolog and miR-320-3p functions to enhance suppression of the IGF1R-PI3K-AKT survival pathway.

Hypertension is a severe public health risk factor worldwide. Elevated angiotensin II (Ang II) produced by the renin-angiotensin-aldosterone system can lead to hypertension and its complications. In this study, we addressed the cardiac-injury effects of Ang II and investigated the signaling mechanism induced by Ang II. Both H9c2 cardiomyoblast cells and neonatal rat cardiomyocytes were exposed to Ang II to observe hypertension-related cardiac apoptosis. The results of western blotting revealed that Ang II significantly attenuated the IGF1R-PI3K-AKT pathway via the Ang II-AT1 receptor axis and phosphatase and tensin homolog expression. Furthermore, real-time PCR showed that Ang II also activated miR-320-3p transcription to repress the PI3K-Akt pathway. In the heart tissue of spontaneously hypertensive rats, activation of the IGF1R survival pathway was also reduced compared with that in Wistar-Kyoto rats, especially in aged spontaneously hypertensive rats. Hence, we speculate that the Ang II-AT1 receptor axis induces both phosphatase and tensin homolog and miR-320-3p expression to downregulate the IGF1R-PI3K-AKT survival pathway and cause cell apoptosis in the heart.

Localization of macrophage subtypes and neutrophils in the prostate tumor microenvironment and their association with prostate cancer racial disparities.

Black men are two to threetimes more likely to die from prostate cancer (PCa) than White men. This disparity is due in part to discrepancies in socioeconomic status and access to quality care. Studies also suggest that differences in the prevalence of innate immune cells and heightened function in the tumor microenvironment of Black men may promote PCa aggressiveness. We evaluated the spatial localization of and quantified CD66ce+ neutrophils by immunohistochemistry and CD68+ (pan), CD80+ (M1), and CD163+ (M2) macrophages by RNA in situ hybridization on formalin-fixed paraffin-embedded tissues from organ donor "normal" prostate (n = 9) and radical prostatectomy (n = 38) tissues from Black and White men. Neutrophils were quantified in PCa and matched benign tissues in tissue microarray (TMA) sets comprised of 560 White and 371 Black men. Likewise, macrophages were quantified in TMA sets comprised of tissues from 60 White and 120 Black men. The phosphatase and tensin homolog (PTEN) and ETS transcription factor ERG (ERG) expression status of each TMA PCa case was assessed via immunohistochemistry. Finally, neutrophils and macrophage subsets were assessed in a TMA set comprised of distant metastatic PCa tissues collected at autopsy (n = 6) sampled across multiple sites. CD66ce+ neutrophils were minimal in normal prostates, but were increased in PCa compared to benign tissues, in low grade compared to higher grade PCa, in PCa tissues from White compared to Black men, and in PCa with PTEN loss or ERG positivity. CD163+ macrophages were the predominant macrophage subset in normal organ donor prostate tissues from both Black and White men and were significantly more abundant in organ donor compared to prostatectomy PCa tissues. CD68,+ CD80,+ and CD163+ macrophages were significantly increased in cancer compared to benign tissues and in cancers with ERG positivity. CD68+ and CD163+ macrophages were increased in higher grade cancers compared to low grade cancer and CD80 expression was significantly higher in benign prostatectomy tissues from Black compared to White men. Innate immune cell infiltration is increased in the prostate tumor microenvironment of both Black and White men, however the composition of innate immune cell infiltration may vary between races.

Transmembrane Phosphatase with TEnsin Homologue (TPTE) Expression in Epithelial Ovarian Cancer

Background: TPTE is a ‘Cancer Testis’ antigen that could be a candidate for targeted immunotherapy of epithelial ovarian cancer.
 Objective: To determine the prevalence of expression and the impact of TPTE on clinical and survival outcomes in epithelial ovarian cancer.
 Methods: Relevant medical information of 173 ovarian cancer patients (including Fallopian and primary peritoneal) managed at a Cancer Centre were retrieved. Reverse-transcriptase polymerase chain reaction (RT-PCR) was used to detect the expression of TPTE in the tumours. TPTE expression was correlated with the clinicopathologic and survival outcomes of the patients.
 Results: TPTE was expressed by 45.1% (78/173) of the tested tumours. There was no significant difference in age between TPTE-positive and negative women (p = 0.93). TPTE expression was not significantly associated with the stage of the disease (p = 1.00), grade of disease (p = 0.71) and histology of the tumour (p = 0.17). There was no significant association between TPTE expression and the ease of optimum debulking (44.5% vs 44.3%, p = 0.54). TPTE expression was also not associated with a better response to therapy (p = 0.05). However, it was associated with slightly longer but not statistically significant progression-free survival (27.5 vs 20.6-months, p = 0.14) and overall survival (49.2 vs 28.0 months, p = 0.11).
 Conclusion: This study shows that TPTE is expressed at a moderate frequency in epithelial ovarian cancers, and its expression is associated with marginally better survival outcomes.

Circular RNA hsa_circ_0077837 is upregulated in non-small cell lung cancer to downregulate phosphatase and tensin homolog through methylation

ABSTRACT Circular RNA (circRNA) hsa_circ_0077837 inhibits colorectal cancer. Our research studied the participation of hsa_circ_0077837 in non-small cell lung cancer (NSCLC). Hsa_circ_0077837 and phosphatase and tensin homolog (PTEN) expression in cancer and paired non-cancer tissues from a total of 64 NSCLC patients were studied with RT-qPCR. To evaluate the prognostic value of hsa_circ_0077837 for NSCLC, these 64 patients were monitored for 5 years. Expression of PTEN in NSCLC cells with hsa_circ_0077837 overexpression was determined by RT-qPCR and Western blot. The methylation of PTEN gene in cells transfected with hsa_circ_0077837 expression vector was analyzed by methylation specific PCR (MSP). The roles of hsa_circ_0077837 and PTEN in NSCLC cell proliferation were evaluated using cell apoptosis assay. Our data showed that hsa_circ_0077837 was upregulated in NSCLC and predicted poor survival. Besides, hsa_circ_0077837 expression level was higher in 36 advanced cases (stage III and IV) than in 28 early-stage cases (stage I and II). Hsa_circ_0077837 was inversely correlated with PTEN across cancer tissues. In NSCLC cells, hsa_circ_0077837 overexpression decreased PTEN expression, increased PTEN gene methylation, and reduced HCC827 cell apoptosis via PTEN. Overall, hsa_circ_0077837 is upregulated in NSCLC and downregulates PTEN by increasing its gene methylation to suppress cell apoptosis. List of abbreviations: Non-small cell lung cancer (NSCLC); circRNAs (circular RNAs); methylation-specific PCR (MSP)

Tumor-derived exosomes induce immunosuppressive macrophages to foster intrahepatic cholangiocarcinoma progression.

Macrophages are prominent components of solid tumors and exhibit distinct functions in different tumor microenvironments. Exosomes are emerging as necessary mediators of the cross-talk between tumor cells and the microenvironment. However, the underlying mechanisms of exosomes involving into crosstalk between tumor cells and macrophages during disease progression of intrahepatic cholangiocarcinoma (ICC) have not been yet fully realized. We found that the macrophages of ICC tumor tissues up-regulated the expression levels of immunosuppressive molecule programmed death-ligand 1 (PD-L1). Increased PD-L1+ macrophages in tumor tissues effectively suppressed T-cell immunity and correlated with poor survival rates in patients with ICC. High-throughput RNA-sequencing analysis that was performed to identify differential levels of microRNAs (miRNAs) between exosomes derived from ICC cells and primary human intrahepatic biliary epithelial cells revealed that miR-183-5p was increased in ICC cell-derived exosomes. Exosomal miR-183-5p inhibited phosphatase and tensin homolog (PTEN) expression, to subsequently affect the elevations on both phosphorylated AKT and PD-L1 expression in macrophages. Furthermore, macrophages that treated with ICC cell-derived exosomes significantly suppressed T-cell immunity in vitro and contributed to the growth and progression of ICC in vivo, which were reversible through blockages on PD-L1 of these macrophages. Finally, clinical data showed that up-regulated levels of plasma exosomal miR-183-5p correlated with poor prognosis of patients with ICC after curative resection. Tumor-derived exosomal miR-183-5p up-regulates PD-L1-expressing macrophages to foster immune suppression and disease progression in ICC through the miR-183-5p/PTEN/AKT/PD-L1 pathway. Exosomal miR-183-5p is a potential predictive biomarker for ICC progression and a potential target for development of therapeutic strategies against immune tolerance feature of ICC.

Endometriosis derived exosomal miR-301a-3p mediates macrophage polarization via regulating PTEN-PI3K axis

This study aimed to explore the effects of endometriosis (EMS)-derived exosomes and miR-301a-3p on the polarization of macrophages and investigate the involved molecular mechanism. The exosomes were isolated from ectopic endometrial tissues of EMS patients and normal human serum (NHS). Results of transmission electron microscope and Nanoparticle Tracking Analysis showed that both EMS-exosomes and NHS-exosomes are about 80 nm microvesicles. Exosomal markers CD63 and TSG101 were abundantly expressed in both EMS-exosomes and NHS-exosomes. No negative marker Calnexin was detected in NHS-exosomes. A small amount of Calnexin was detected in EMS-exosomes. THP-1 cells differentiatee to macrophages by incubating with phorbol-12-myristate-13-acetate. Effects of the exosomes on the phagocytosis and polarization of macrophages were evaluated by PKH26 fluorescent labeling and flow cytometry, respectively. Compared with the NHS-exosomes group, the phagocytic capacity of macrophages was reduced and the polarization of macrophages to M2 macrophages was promoted after EMS-exosomes treatment. Results of western blot showed that compared with the NHS-exosomes group, the EMS-exosomes treatment significantly up-regulated the expression of phosphatidylinositol 3-kinase (PI3K) and down-regulated the expression of phosphatase and tensin homologue deleted on chromosome 10 (PTEN). miR-301a-3p mimic, negative control (NC) mimic, miR-301a-3p inhibitor and NC inhibitor were transfected into cells. Transfection efficiency was confirmed by RT-qPCR. Effects of the miR-301a-3p expression on the macrophages polarization and the expression of Arg-1, PTEN and PI3K in the macrophages were evaluated by flow cytometry and western blot, respectively. miR-301a-3p overexpression significantly enhanced the ability of EMS-exosomes-inducing M2 transformation of macrophages, promoted the expression of Arg-1 and PI3K, and inhibited the PTEN expression. miR-301a-3p inhibitor significantly reduced the expression of Arg-1 and PI3K and promoted the PTEN expression. In conclusion, EMS derived exosomal miR-301a-3p mediated macrophage polarization via regulating PTEN-PI3K axis.

Retraction: MicroRNA-20b (miR-20b) Promotes the Proliferation, Migration, Invasion, and Tumorigenicity in Esophageal Cancer Cells via the Regulation of Phosphatase and Tensin Homologue Expression.

Retraction: MicroRNA-20b (miR-20b) Promotes the Proliferation, Migration, Invasion, and Tumorigenicity in Esophageal Cancer Cells via the Regulation of Phosphatase and Tensin Homologue Expression.

Immunohistochemical Analysis of TP53 and PTEN Expression in Glioblastoma Multiforme Patients of Western Rajasthan, India: An Observational Study

Introduction: Glioblastoma Multiforme (GBM) is the most aggressive brain tumour with a dismal prognosis. Very few studies on its diagnosis, prognosis and therapeutics have been attempted in the past on Indian population. Standard treatment of this highly aggressive tumour yields little survival benefit; hence, greater attention is now being paid to personalised treatment and, correspondingly, to the expression of specific molecular markers with the goal of assessing their possible therapeutic as well as prognostic significance. Aim: To estimate the proportion of Tumour Protein 53 (TP53) and PTEN (Phosphatase and Tensin Homolog) expression in GBM patients of Western Rajasthan, India. Materials and Methods: This study was a ambispective, single institutional observational study done on 35 brain tissue biopsies of histopathologically diagnosed and confirmed cases of GBM based on the World Health Organisation (WHO) classification, 2007 received in Department of Pathology, Dr. Sampurnanand Medical College (Dr. SNMC), Jodhpur, Rajasthan, India, from January 2015 to December 2020 (January 2015 to September 2018 Retrospective and October 2018 to December 2020 Prospective) after applying inclusion and exclusion criteria. Immunohistochemical (IHC) analysis was done for TP53 and PTEN markers in all cases of GBM. The results were then applied for statistical analysis using Statistical Package for the Social Sciences (SPSS) version 22.0 software package (SPSS Inc., Chicago, IL, USA). The association between age and gender with TP53 and PTEN positive cases, respectively, was analysed by using Fisher’s-exact test and the results of the same were compiled. Results: TP53 expression was seen in 32 cases (91.4%). The mean age of presentation of TP53 positivity was 50.3 years. Most of the TP53 cases occurred in the 41 to 50 and 61 to 70 years of age groups. In TP53 mutated cases, males were found more commonly affected as compared to females. Overall, the majority of cases (eight cases) occurred in the temporal region of the brain (25%). The relationship between age and gender with TP53 expression was found to be insignificant. PTEN expression was found absent (mutation positive) in 11 cases (32.4%). Mean age of these patients was 52.5 years. The male to female ratio was found to be 1.8:1. Regarding tumour location in the brain, most of the cases occurred unilaterally, with 45.4% (n=5) of cases occurring in the temporal region. The association between PTEN mutation with age and gender was not found to be significant. Conclusion: The higher prevalence of TP53 expression in the population suggests distinct genetic pathways that need to be studied in detail to have a better understanding of this highly aggressive tumour. The PTEN mutation was discovered to be prevalent in the population of Western Rajasthan and needs to be studied further on a large scale. The simultaneous presence of molecular markers in GBM cases would need to be considered before initiating any gene therapy for its improved effectiveness.

Relationship between phosphatase and tensin homolog (PTEN) expression in high grade glioma and histopathologic findings

Introduction. Malignant glioma is resistant brain tumor to treatment and considered by aggressiveness that fails successful resection. Molecular pathways including PTEN related with tumor behavior. Materials and methods. We studied the immunohistochemical expression of PTEN in 32 brain surgical resection specimens with different histologic grades. All samples were from pathology department of Sina hospital in Tehran-Iran from 2020-2021. Results. From 32 patients, 21 (65.6%) had no PTEN staining. There was significant relationship between high age and no PTEN expression and average age with no PTEN staining was 54.05±14.01 years (P value: 0.044). There was significant relationship between necrosis in histopathologic evaluation with no PTEN staining (P value: 0.016). Also, there was no significant relationship between sex, tumor’s size, Tumor’s site, tumor’s grade, and primary or secondary type of tumor with PTEN staining (P value > 0.05). Conclusion. PTEN expression related to histopathologic features such as necrosis and age. PTEN can be introduced as an important prognostic indicator in high grade.

USP20 mitigates ischemic stroke in mice by suppressing neuroinflammation and neuron death via regulating PTEN signal

Ischemic stroke is a leading cause of death worldwide. The lack of effective pharmacotherapies for ischemic stroke is mainly attributed to the incomplete understanding of its pathogenesis. Deubiquitinase ubiquitin-specific protease 20 (USP20) plays an important role in regulating multiple cellular processes. However, its effects on cerebral ischemic stroke still remain unknown. In the present study, we found that USP20 expression was markedly increased in the early phase of ischemic stroke in mice with middle cerebral artery occlusion (MCAO) operation, and were then considerably decreased in mice with ischemia reperfusion (I/R) injury. Double immunofluorescence staining showed USP20 abundance in both microglial cells and neurons. We then found that promoting USP20 expression remarkably ameliorated MCAO-induced ischemic brain injury, along with significantly reduced infarct volume, neurological scores and brain water contents. In addition, cognitive impairments in MCAO-operated mice were considerably alleviated by USP20 over-expression. Furthermore, USP20 over-expression dramatically restrained microglial activation, inflammatory response and neuronal death in mice with ischemic stroke. Moreover, our results indicated that phosphatase and tensin homolog (PTEN) expression was highly decreased in the infarct areas of MCAO-treated mice, while being greatly rescued by USP20 over-expression. All these effects mediated by USP20 during cerebral I/R injury were confirmed in the cultured primary microglial cells and cortical neurons stimulated by oxygen-glucose deprivation and reoxygenation (OGD/R). Mechanistically, we found that USP20 directly interacted with PTEN. Notably, suppressing PTEN with its specific inhibitor dramatically abolished the function of USP20 to ameliorate neuroinflammation and neuron death induced by OGD/R. Collectively, our results illustrated that USP20 could effectively mitigate the severity of cerebral ischemic stroke and improve behavior deficits in MCAO-operated mice, and identified the USP20/PTEN axis as a promising therapeutic target for ischemic stroke treatment.

Hsa_circ_0007059 sponges miR-421 to repress cell growth and stemness in hepatocellular carcinoma by the PTEN-AKT/mTOR pathway

BackgroundHepatocellular carcinoma (HCC) is a substantial health concern worldwide. Increasing studies have suggested that circle RNAs (circRNAs) function as new regulators in HCC progression. The present work explored the role of hsa_circ_0007059 (circ_0007059) in the developing process of hepatocarcinogenesis. MethodsThe circ_0007059 level in HCC was determined by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) and northern blot. Its biological role in HCC cells was assessed using 3-(4,5-Dimethylthiazol-2-yl)− 2,5-diphenyltetrazolium bromide (MTT), colony formation, flow cytometry, Transwell, sphere formation and western blotting analyses. Bioinformatics analysis, luciferase reporter, and RNA immunoprecipitation (RIP) assays were used to test the regulatory mechanisms of circ_0007059. ResultsOur results revealed that circ_0007059 expression was downregulated in HCC samples and cells. Moreover, circ_0007059 overexpression inhibited HCC cell proliferation, migration, invasion, and stem cell-like property, and strengthened cell apoptosis. In mechanism, circ_0007059 suppressed AKT/mTOR pathway by positively regulating phosphatase and tensin homolog (PTEN) expression. Additionally, circ_0007059 acted as a positive regulator of PTEN through controlling the availability of miR-421. Rescue assays demonstrated that PTEN knockdown or SC79 (AKT agonist) eliminated the effect of circ_0007059 on HCC cell phenotypes. ConclusionCirc_0007059 sponges miR-421 to inhibit oncogenic cellular process in HCC by mediating the PTEN-AKT/mTOR pathway.

Abstract MP28: The Bet Bromodomain Inhibitor, (+)-JQ1, Inhibits Neointima Formation Following Acute Vascular Injury Via Pten Upregulation

The primary aim of this work was to identify compounds that upregulate phosphatase and tensin homolog (PTEN) expression in smooth muscle cells (SMCs), with the expectation that PTEN upregulation would inhibit pathological vascular remodeling by promoting SMC homeostasis. Our recent work demonstrated that PTEN is an important regulator of SMC phenotype. SMC-specific PTEN deletion promotes spontaneous vascular remodeling and PTEN loss correlates with increased atherosclerotic lesion severity in human coronary arteries. In mice, PTEN overexpression reduces plaque area and preserves SMC contractile protein expression in atherosclerosis and blunts Angiotensin-II-induced pathological vascular remodeling, suggesting that pharmacologic PTEN upregulation could be a novel therapeutic approach to treat vascular disease. Currently, there are few known pharmacologic inducers of PTEN, however, we have shown that (+)-JQ1, which targets the epigenetic reader protein, Brd4, directly activates the PTEN promoter to drive PTEN expression. Mechanistically, our findings suggest that Brd4 inhibition results in p300-mediated hyper-acetylation of the PTEN promoter to increase PTEN transcriptional activity. Administration of (+)-JQ1 or SMC-specific Brd4 deletion inhibited neointima formation following acute carotid artery injury in mice. Using SMC-specific PTEN depletion both in vitro and in vivo, we showed that the observed anti-remodeling, anti-inflammatory effects were PTEN-dependent. Furthermore, we tested the effects of (+)-JQ1 on macrophage polarization, as systemic drug delivery could potentially modulate the phenotype of other resident vascular cells, including macrophages. We found that (+)-JQ1 inhibited bone marrow-derived macrophage polarization towards a pro-inflammatory phenotype, which is notable because vascular inflammation driven by SMC-macrophage cross-talk is known to promote neointima development. Importantly, our findings may hold direct clinical relevance, as BET bromodomain inhibitors related to (+)-JQ1 are currently undergoing clinical trials. These results are significant because they indicate that targeting PTEN upregulation in SMCs is a completely novel approach to inhibit vascular remodeling.

ACY1 regulating PTEN/PI3K/AKT signaling in the promotion of non-small cell lung cancer progression.

BackgroundNon-small cell lung cancer (NSCLC) has a poor prognosis and is the most common cause of cancer-related deaths worldwide. Aminoacylase 1 (ACY1) plays a promoting role in some cancers, but its role in NSCLC is still unclear.MethodsImmunohistochemistry, Reverse transcription-polymerase chain reaction (RT-PCR) and western blotting assays were used to determine ACY1 expression patterns in NSCLC tissues and cell lines. The clinical significance of ACY1 in NSCLC was evaluated by χ2 test and Kaplan-Meier analysis. MTT, flow cytometry, wound healing, and Transwell assays were performed to assess cell growth, apoptosis, migration, invasion, and tumorigenesis under different treatments. Male athymic BALB/C nude mice were used for xenotransplantation experiments.ResultsThe results showed that ACY1 expression was elevated in NSCLC tissue samples and cells, and high ACY1 expression predicted an advanced clinical process and shorter overall survival in patients with NSCLC. Overexpression of ACY1 significantly increased cell growth, migration, invasion, and tumorigenesis, and reduced cell apoptosis, indicating that ACY1 functions as an oncogene in NSCLC. Moreover, ACY1 decreased phosphatase and tensin homolog (PTEN) expression, increased its ubiquitination, and activated PI3K/AKT signaling. Overexpression of PTEN diminished the effects of ACY1 upregulation on cell tumorigenesis promotion.ConclusionsThis study reveals that ACY1 may promote the progression of NSCLC via activating PI3K/AKT signaling in a PTEN-dependent manner. Our study may provide a better understanding of the pathogenesis and development of NSCLC.

P21-activated kinase 4 phosphorylates peroxisome proliferator-activated receptor Υ and suppresses skeletal muscle regeneration.

BackgroundSkeletal muscle regeneration is an adaptive response to injury that is crucial to the maintenance of muscle mass and function. A p21‐activated kinase 4 (PAK4) serine/threonine kinase is critical to the regulation of cytoskeletal changes, cell proliferation, and growth. However, PAK4's role in myoblast differentiation and regenerative myogenesis remains to be determined.MethodsWe used a mouse model of myotoxin (notexin)‐induced muscle regeneration. In vitro myogenesis was performed in the C2C12 myoblast cell line, primary myoblasts, and primary satellite cells. In vivo overexpression of PAK4 or kinase‐inactive mutant PAK4S474A was conducted in skeletal muscle to examine PAK4's kinase‐dependent effect on muscle regeneration. The regeneration process was evaluated by determining the number and size of multinucleated myofibres and expression patterns of myogenin and eMyHC. To explore whether PAK4 inhibition improves muscle regeneration, mice were injected intramuscularly with siRNA that targeted PAK4 or orally administered with a chemical inhibitor of PAK4.Resultsp21‐activated kinase 4 was highly expressed during the myoblast stage, but expression gradually and substantially decreased as myoblasts differentiated into myotubes. PAK4 overexpression, but not kinase‐inactive mutant PAK4S474A overexpression, significantly impeded myoblast fusion and MyHC‐positive myotube formation in C2C12 cells, primary myoblasts, and satellite cells (P < 0.01). Conversely, PAK4 silencing led to an 8.7% and a 20.3% increase in the number of multinucleated larger myotubes in C2C12 cells and primary myoblasts. Further, in vivo overexpression of PAK4 by adenovirus injection to mice prior to and after myotoxin‐induced injury led to a 52.6% decrease in the number of eMyHC‐positive myofibres on Day 5 in tibialis anterior muscles as compared with those injected with control adenoviruses (P < 0.01), while Ad‐PAK4S474A showed comparable muscle regeneration parameters. PAK4‐induced repression of muscle regeneration coincided with an increase in phosphatase and tensin homologue (PTEN) expression and a decrease in phosphoinositide 3‐kinase‐Akt signalling. In contrast, PAK4 silencing reduced PTEN expression in mice. Consistent with these findings, prodrug of PAK4 inhibitor CZh‐226 (30 mg/kg) orally administered to mice repressed PTEN expression and accelerated myotube formation. Subsequent mechanistic studies revealed that PAK4 directly phosphorylates PPARγ at S273 to increase its transcription activity, thereby up‐regulating PTEN expression. Importantly, an analysis of the Genotype‐Tissue Expression database showed a positive correlation between PAK4 and PTEN in human skeletal muscle tissues (P < 0.01).Conclusionsp1‐activated kinase 4 is a new member of PPARγ kinase, and PAK4 inhibition may have a therapeutic role as an accelerant of muscle regeneration.

Long noncoding RNA ALOX12-AS1 inhibits cervical cancer cells proliferation via targeting miR-3171.

Cervical cancer is a common female malignancy worldwide, and the molecular mechanism of cervical tumorigenesis remains poorly understood. A large piece of evidence have demonstrated the important roles of long noncoding RNAs (lncRNAs) in tumorigenesis, cancer progression and drug resistance. In this study, we comprehensively analyzed the lncRNAs expression pattern in cervical cancer using RNA sequencing and microarray data from the cancer genome atlas, gene expression omnibus and Genotype Tissue Expression. Moreover, we assessed the correlation between lncRNA expression levels and cervical cancer patient's survival. We uncovered hundreds of lncRNAs that are upregulated or downregulated in cervical cancer tissues. Among these aberrantly lncRNAs, some are significantly associated with cervical patients' poorer prognosis, such as ALOX12-AS1 and LINC00173. ALOX12-AS1 expression is downregulated in cervical cancer, and over-expression of ALOX12-AS1 could inhibit cervical cancer cells proliferation in vitro. Further, mechanistically investigation revealed that ALOX12-AS1 could interact with AGO2 and sponge miR-3171, thereby antagonizing its' repression of tumor suppressor phosphatase and tensin homolog expression in cervical cancer cell. Taken together, this study provides lncRNA candidates in cervical cancer and highlights the critical role of ALOX12-AS1 in cervical cancer.

PolyI:C suppresses TGF-β1-induced Akt phosphorylation and reduces the motility of A549 lung carcinoma cells.

Epithelial mesenchymal transition (EMT) is a critical process involved in the invasion and metastasis of cancer, including lung cancer (LC). Transforming growth factor (TGF)-β is one of factors capable of inducing EMT. Polyinosinic-polycytidylic acid (polyI:C), a synthetic agonist for toll-like receptor (TLR) 3, can enhance immune responses and has been used as an adjuvant for cancer vaccines; however, it remains unclear whether it influences other process, such as EMT. In the present study, we examined the effects of polyI:C on TGF-β-treated A549 human LC cells. By in vitro cell proliferation assay, polyI:C showed no effect on the growth of A549 cells treated with TGF-β1 at the concentration range up to 10μg/ml; however, it markedly suppressed the motility in a cell scratch and a cell invasion assay. By Western blotting, polyI:C dramatically decreased TGF-β1-induced Ak strain transforming (Akt) phosphorylation and increased phosphatase and tensin homologue (PTEN) expression without affecting the Son of mothers against decapentaplegic (Smad) 3 phosphorylation or the expression level of E-cadherin, N-cadherin or Snail, indicating that polyI:C suppressed cell motility independently of the 'cadherin switching'. The Akt inhibitor perifosine inhibited TGF-β1-induced cell invasion, and the PTEN-specific inhibitor VO-OHpic appeared to reverse the inhibitory effect of polyI:C. PolyI:C has a novel function to suppress the motility of LC cells undergoing EMT by targeting the phosphatidylinositol 3-kinase/Akt pathway partly via PTEN and may prevent or reduce the metastasis of LC cells.