Overexpression Of PTEN Research Articles

Phosphatase and Tensin Homolog Deleted on Chromosome Ten Knockdown Attenuates Cognitive Deficits by Inhibiting Neuroinflammation in a Mouse Model of Perioperative Neurocognitive Disorder

Phosphatase and tensin homolog deleted on chromosome ten (PTEN) is a crucial regulator of neuronal development, neuronal survival, axonal regeneration, and synaptic plasticity. In this study we examined the potential role of PTEN in cognitive function in a mouse model of perioperative neurocognitive disorder (PND). Adult male C57BL/6J mice received intracerebroventricular injections of small interfering RNA (siRNA) against PTEN or control siRNA 3 days prior to exploratory laparotomy (n = 8 per group). A group of healthy mice not undergoing surgery included as additional control. Barnes maze and fear conditioning tests were conducted 7 days after surgery. Mice were then sacrificed to examine the expression of PTEN, AMP-activated protein kinase (AMPK), ionized calcium binding adaptor molecule (Iba)-1, B-cell lymphoma (Bcl)-2, Bcl2-associated X protein (Bax), interleukin (IL)-1β, and tumor necrosis factor (TNF)-α in the hippocampus. The microglial activation was examined by immunohistochemistry using Iba-1 as a microglia maker. Nissl and terminal transferase deoxyuridine triphosphate nick-end labeling (TUNEL) staining were used to measure cell death and apoptosis. In comparison to the healthy controls, surgically treated mice had longer latency to identify the target box in both training and testing sessions in the Barnes maze test and shorter freezing time in the fear conditioning test. Surgically treated mice had increased expression of PTEN, AMPK, Bax, IL-1β, and TNF-α, as well as increasing number of activated microglia and apoptosis neurons in the hippocampus. PTEN knockdown significantly attenuated the behavioral deficits in Barnes maze and fear conditioning tests, as well as over-expression of PTEN, AMPK, Bax, IL-1β, and TNF-α induced by surgery. PTEN knockdown could attenuate cognitive deficits induced by trauma, likely through inhibiting the activation of microglia.

CircRAB3B suppresses proliferation, motility, cell cycle progression and promotes the apoptosis of IL-22-induced keratinocytes depending on the regulation of miR-1228-3p/PTEN axis in psoriasis

Introduction Psoriasis is an immune-related chronic skin disease, and interleukin-22 (IL-22) is involved in psoriasis pathogenesis through promoting proliferation and migration abilities of keratinocytes. Here, we analysed the role of circular RNA (circRNA) RAB3B, member RAS oncogene family (circRAB3B) in regulating the phenotypes of IL-22-induced HaCaT cells. Methods RT-qPCR was implemented to assess RNA abundance. Western blot assay was adopted to assess protein abundance. Cell proliferation capacity was examined by cell counting kit-8 (CCK8) assay and 5-ethynyl-2′-deoxyuridine (Edu) assay. Cell motility was assessed by transwell assays and wound healing assay. Flow cytometric analysis was utilized to evaluate cell cycle progression and apoptosis. The intermolecular binding relations were tested via dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. CircRAB3B expression was reduced in psoriatic cutaneous specimens and IL-22-treated HaCaT cells. Results CircRAB3B overexpression hampered the proliferation, motility, and cell cycle progression and elevated the apoptotic rate of IL-22-treated HaCaT cells, and circRAB3B silencing exhibited opposite effects in IL-22-induced HaCaT cells. CircRAB3B acted as microRNA-1228-3p (miR-1228-3p) sponge in HaCaT cells, and miR-1228-3p overexpression largely overturned circRAB3B overexpression-induced effects in HaCaT cells. MiR-1228-3p interacted with phosphatase and tensin homolog (PTEN), and circRAB3B sponged miR-1228-3p to induce PTEN level. MiR-1228-3p accumulation-mediated effects were partly alleviated by PTEN overexpression in HaCaT cells upon IL-22 treatment. Conclusions CircRAB3B suppressed psoriasis progression partly through down-regulating miR-1228-3p and up-regulating PTEN.

LncRNA MT1JP-overexpression abolishes the silencing of PTEN by miR-32 in hepatocellular carcinoma.

Previous studies have shown that long non-coding RNA (lncRNA) MT1JP plays a role as a tumor suppressor in several types of cancer. The present study aimed to explore the role of MT1JP in hepatocellular carcinoma (HCC). Paired HCC and non-tumor tissues from 64 patients with HCC were subjected to RNA isolation and reverse transcription-quantitative PCR (RT-qPCR) to analyze the differential expression of MT1JP, microRNA (miR)-32 and phosphatase and tensin homolog (PTEN) in HCC. Cell transfections, followed by RT-qPCR and western blotting, were carried out to investigate the interactions among MT1JP, miR-32 and PTEN. The role of MT1JP, miR-32 and PTEN in regulating HCC cell proliferation was assessed using a Cell Counting Kit-8 assay. It was found that MT1JP was downregulated in HCC cancer tissues compared with that in non-cancer tissues. Survival analysis showed that patients with low MT1JP expression levels exhibited a significantly higher 5-year overall survival rate compared with patients with high MT1JP levels. The expression of MT1JP in HCC tissues was positively associated with PTEN and negatively associated with miR-32. Overexpression of MT1JP increased the expression levels of PTEN and decreased the expression levels of miR-32. Overexpression of miR-32 did not affect the expression of MT1JP but decreased the expression levels of PTEN and attenuated the effect of overexpression of MT1JP on the expression of PTEN. Overexpression of MT1JP and PTEN decreased the proliferation of HCC cells. Overexpression of miR-32 played an opposite role and attenuated the effects of overexpression of MT1JP. Therefore, MT1JP may upregulate PTEN by downregulating miR-32 to regulate HCC cell proliferation.

Notch3 inhibits cell proliferation and tumorigenesis and predicts better prognosis in breast cancer through transactivating PTEN

Notch receptors (Notch1–4) play critical roles in tumorigenesis and metastasis of malignant tumors, including breast cancer. Although abnormal Notch activation is related to various tumors, the importance of single receptors and their mechanism of activation in distinct breast cancer subtypes are still unclear. Previous studies by our group demonstrated that Notch3 may inhibit the emergence and progression of breast cancer. PTEN is a potent tumor suppressor, and its loss of function is sufficient to promote the occurrence and progression of tumors. Intriguingly, numerous studies have revealed that Notch1 is involved in the regulation of PTEN through its binding to CBF-1, a Notch transcription factor, and the PTEN promoter. In this study, we found that Notch3 and PTEN levels correlated with the luminal phenotype in breast cancer cell lines. Furthermore, we demonstrated that Notch3 transactivated PTEN by binding CSL-binding elements in the PTEN promoter and, at least in part, inhibiting the PTEN downstream AKT-mTOR pathway. Notably, Notch3 knockdown downregulated PTEN and promoted cell proliferation and tumorigenesis. In contrast, overexpression of the Notch3 intracellular domain upregulated PTEN and inhibited cell proliferation and tumorigenesis in vitro and in vivo. Moreover, inhibition or overexpression of PTEN partially reversed the promotion or inhibition of cell proliferation induced by Notch3 alterations. In general, Notch3 expression positively correlated with elevated expression of PTEN, ER, lower Ki-67 index, and incidence of involved node status and predicted better recurrence-free survival in breast cancer patients. Therefore, our findings demonstrate that Notch3 inhibits breast cancer proliferation and suppresses tumorigenesis by transactivating PTEN expression.

Silencing miRNA-1297 suppresses the invasion and migration of prostate cancer cells via targeting modulation of PTEN and blocking of the AKT/ERK pathway.

Phosphatase and tensin homolog (PTEN) loss is a major contributing factor of prostate cancer (PC). miRNA-1297 was reported to serve role in various cancer types; however, the potential roles of miRNA-1297 in PC had not been investigated. In the present study, tumor and adjacent tissues were collected from patients with PC. The gene expression level of miRNA-1297 was measured via polymerase chain reaction. Results indicated that the miRNA-1297 was overexpressed in tumor tissues from PC patients and in PC cell lines. miRNA-1297 also contributed toward the progression of PC. PTEN was confirmed as the direct target of miRNA-1297 and bound with miRNA-1297 via four binding sites. The miRNA-1297 level was negatively associated with the PTEN level. Silencing miRNA-1297 or overexpression of PTEN significantly inhibited the cell migration and invasion. In addition, the AKT/ERK pathway was also inhibited following silencing of miRNA-1297 or overexpression of PTEN. Taken together, the results indicated that silencing miRNA-1297 exerted inhibitory effects on the invasion and migration of PC cells via modulating PTEN and blocking of the AKT/ERK pathway. The results of the present study provided a novel strategy for treatment of prostate cancer cells.

Metformin prevents BAFF activation of Erk1/2 from B-cell proliferation and survival by impeding mTOR-PTEN/Akt signaling pathway

B-cell activating factor (BAFF) is an essential cytokine for B-cell maturation, differentiation and survival, and excess BAFF induces aggressive or neoplastic B-cell disorders and contributes to development of autoimmune diseases. Metformin, an anti-diabetic drug, has recently garnered a great attention due to its anti-proliferative and immune-modulatory features. However, little is known regarding the effect of metformin on BAFF-stimulated B cells. Here, we show that metformin attenuated human soluble BAFF (hsBAFF)-induced cell proliferation and survival by blocking the Erk1/2 pathway in normal and B-lymphoid (Raji) cells. Pretreatment with U0126, knockdown of Erk1/2, or expression of dominant negative MKK1 strengthened metformin’s inhibition of hsBAFF-activated Erk1/2 and B-cell proliferation/viability, whereas expression of constitutively active MKK1 rendered high resistance to metformin. Further investigation found that overexpression of wild type PTEN or ectopic expression of dominant negative Akt potentiated metformin's suppression of hsBAFF-induced Erk1/2 activation and proliferation/viability in Raji cells, implying a PTEN/Akt-dependent mechanism involved. Furthermore, we noticed that metformin hindered hsBAFF-activated mTOR pathway in B cells. Inhibition of mTOR with rapamycin or knockdown of mTOR enhanced metformin’s suppression of hsBAFF-induced phosphorylation of S6K1, PTEN, Akt, and Erk1/2, as well as B-cell proliferation/viability. These results indicate that metformin prevents BAFF activation of Erk1/2 from cell proliferation and survival by impeding mTOR-PTEN/Akt signaling pathway in normal and neoplastic B-lymphoid cells. Our findings support that metformin has a great potential for prevention of excessive BAFF-induced aggressive B-cell malignancies and autoimmune diseases.

LncRNA AK087124/miR-224-5p/PTEN axis modulates endothelial cell injury in atherosclerosis through apoptosis and AKT signaling pathway

Noncoding RNAs (ncRNAs) have been shown to play important roles in atherosclerosis-related endothelial cells dysfunction during atherosclerosis processes. In the study, our purpose was to discover new long noncoding RNAs (lncRNAs) and microRNAs (miRNAs) via competitively interacting each other to regulate the pathogenesis process of atherosclerosis. We investigated the roles of lncRNA AK087124 and miR-224-5p in atherosclerotic pathogenesis and found that AK087124 was up-regulated while miR-224-5p was down-regulated in in the plasma and plaque from atherosclerotic mice compared with normal mice. Ox-LDL was used to establish the mouse aorta endothelial cell (MAEC) injury model. The function study indicated that knockdown of AK087124 inhibited ox-LDL induced endothelial apoptosis and inflammatory response. Bioinformatic prediction combining with luciferase assays indicated that AK087124 could sponge miR-224-5p and enhance the PTEN expression which is a target of miR-224-5p. RNA pull down assays also showed that biotin-miR-224-5p probe could interacted directly with AK087124 and PTEN. Pearson correlation analysis further demonstrated that AK087124 and PTEN expression are negatively correlated with miR-224-5p. Rescue study revealed that miR-224-5p silencing and PTEN overexpression both can reverse the effect of AK087124 on the ox-LDL induced endothelial injury. These data indicated that AK087124 and miR-224-5p could be potential biomarkers and target molecules to treatment and diagnosis for atherosclerosis.

Interference with lncRNA NEAT1 promotes the proliferation, migration, and invasion of trophoblasts by upregulating miR-411-5p and inhibiting PTEN expression

Background: Preeclampsia (PE) is an idiopathic hypertensive disorder of pregnancy, which is related to abnormal placental villi development. Our previous study has found that lncRNA NEAT1 promotes apoptosis of trophoblasts, but the role of NEAT1 in proliferation, migration, and invasion is still unclear. This study explores the role of NEAT1 in proliferation, migration, and invasion of trophoblasts. Methods: NEAT1 and miR-411-5p levels were detected by quantitative real-time PCR. Colony formation assay detected cell proliferation and transwell assay detected cell migration and invasion. Dual-luciferase reporter assay detected the binding between NEAT1 and miR-411-5p as well as the binding between miR-411-5p and PTEN. RNA pull-down assay detected the combination between NEAT1 and miR-411-5p. Result: NEAT1 was increased and miR-411-5p was reduced in PE patients and human trophoblasts (HTR8/SVneo cells) that were induced with H2O2. Interference with NEAT1 promoted cell proliferation, migration, and invasion, and the miR-411-5p inhibitor reversed the effect of siRNA-NEAT1. The expression of PTEN was promoted in PE patients and HTR8/SVneo cells that were induced with H2O2, while the miR-411-5p mimic inhibited PTEN expression, and the plasmid-mediated PTEN overexpression reversed the effect of the miR-411-5p mimic. Besides, under H2O2 induction, the miR-411-5p mimic promoted cell proliferation, migration, and invasion, and the plasmid-mediated PTEN overexpression reversed the effect of the miR-411-5p mimic. Conclusion: Interference with lncRNA NEAT1 promoted the proliferation, migration, and invasion of trophoblasts and alleviated the development of PE, which was partly mediated by upregulating miR-411-5p and inhibiting PTEN expression.

MiR-195-5p Ameliorates Cerebral Ischemia-Reperfusion Injury by Regulating the PTEN-AKT Signaling Pathway

BackgroundMiR-195-5p has been shown to play crucial roles in tumor inhibition, but its biological functions in cerebral ischemia-reperfusion (I/R) injury are unclear.MethodsTo mimic cerebral I/R injury, mice were induced by transient middle cerebral artery occlusion (MCAO). Human brain microvascular endothelial cells (HBMVECs) were treated with oxygen-glucose deprivation (OGD) to mimic I/R injury in vitro. The expression of miR-195-5p and PTEN was detected by qRT-PCR or Western blot. Cell viability was evaluated by CCK-8 assay. Cell apoptosis was detected by flow cytometer. Cell death was detected using specific lactate dehydrogenase (LDH) cytotoxicity kit. Infarct volume in mice brains was evaluated by TTC staining. Histopathological analysis was performed by HE staining and TUNEL staining. The interaction between miR-195-5p and PTEN was determined by TargetScan and luciferase reporter assay.ResultsMiR-195-5p was significantly downregulated and PTEN was upregulated during cerebral I/R injury both in vitro and in vivo. Overexpression of miR-195-5p efficiently enhanced cell viability, while reduced LDH release and apoptotic rate of OGD-treated HBMVECs in vitro. MiR-195-5p could negatively regulate the expression of PTEN by directly binding to its 3′-UTR. Overexpression of PTEN obviously attenuated the protective effect of miR-195-5p mimics on cell viability, LDH release and apoptosis in OGD-treated HBMVECs. Meanwhile, overexpression of miR-195-5p increased the expression levels of p-AKT in OGD-treated HBMVECs, while this effect was reversed by overexpression of PTEN. Moreover, overexpression of miR-195-5p efficiently ameliorated brain injury of mice after MCAO treatment in vivo.ConclusionOverexpression of miR-195-5p ameliorated cerebral I/R injury by regulating the PTEN-AKT signaling pathway, providing a potential therapeutic target for cerebral I/R injury.

Inhibition Sequence of miR-205 Hinders the Cell Proliferation and Migration of Lung Cancer Cells by Regulating PETN-Mediated PI3K/AKT Signal Pathway.

The aim of this study was to identify the pro-tumor role of miR-205 in patients with lung cancer (LC) on the cell proliferation and migration through regulating PTEN-mediated PI3K/AKT signal pathway. Paired cancer tissues and adjacent tissues were collected from 107 LC patients who received treatment in Jinan Central hospital. In addition, the purchased LC cell lines were transfected into HCC827 cell line to observe and compare the biological behaviors. Compared with adjacent tissues, miR-205 was statistically higher in LC tissues, while PTEN was notably lower (P < 0.05). Inhibition of miR-205 not only suppressed cell proliferation, migration and invasion, increased apoptosis rate, but regulated epithelial mesenchymal transformation (EMT)-related proteins. Likewise, overexpression of PETN played the same role as that of miR-205 inhibition sequence. Inhibited miR-205 or PTEN overexpression brought dramatically decreased PI3K and p-Akt. The relationship between miR-205 and PTEN was verified through the biological prediction website and luciferase reporter. Co-transfection experiments revealed that after cotransfection of miR-205 inhibitor and si-PETN, the cell proliferation and invasion showed no marked difference between cotransfection group and NC group. MiR-205 is involved in LC cell proliferation and migration by regulating PETN-mediated PI3K/AKT signal pathway, which may be a feasible treatment target for LC in clinical practice.

PTEN in prefrontal cortex is essential in regulating depression-like behaviors in mice

Chronic stress is an environmental risk factor for depression and causes neuronal atrophy in the prefrontal cortex (PFC) and other brain regions. It is still unclear about the molecular mechanism underlying the behavioral alterations and neuronal atrophy induced by chronic stress. We here report that phosphatase and tensin homolog deleted on chromosome ten (PTEN) is a mediator for chronic stress-induced depression-like behaviors and neuronal atrophy in mice. One-month chronic restraint stress (CRS) up-regulated PTEN signaling pathway in the PFC of mice as indicated by increasing levels of PTEN, p-MEK, and p-ERK but decreasing levels of p-AKT. Over-expression of Pten in the PFC led to an increase of depression-like behaviors, whereas genetic inactivation or knockdown of Pten in the PFC prevented the CRS-induced depression-like behaviors. In addition, systemic administration of PTEN inhibitor was also able to prevent these behaviors. Cellular examination showed that Pten over-expression or the CRS treatment resulted in PFC neuron atrophy, and this atrophy was blocked by genetic inactivation of Pten or systemic administration of PTEN inhibitor. Furthermore, possible causal link between Pten and glucocorticoids was examined. In chronic dexamethasone (Dex, a glucocorticoid agonist) treatment-induced depression model, increased PTEN levels were observed, and depression-like behaviors and PFC neuron atrophy were attenuated by the administration of PTEN inhibitor. Our results indicate that PTEN serves as a key mediator in chronic stress-induced neuron atrophy as well as depression-like behaviors, providing molecular evidence supporting the synaptic plasticity theory of depression.

Phosphatase and tensin homolog (PTEN) suppresses triacylglycerol accumulation and monounsaturated fatty acid synthesis in goat mammary epithelial cells

Phosphatase and tensin homolog (PTEN) is a well-known tumor suppressor in nonruminants and regulates various cellular processes including growth through dephosphorylation of phosphoinositide substrates. Although studies with bovine mammary tissue suggested a role for PTEN during lactation, its potential role in lipid metabolism remains unknown. Objectives of the present study were to determine PTEN abundance in goat mammary tissue at 2 stages of lactation (n = 6 Xinong Saanen dairy goats per stage), and to use gene-silencing and adenoviral transfections in vitro with isolated goat mammary epithelial cells (GMEC) to evaluate the role of PTEN abundance of lipid metabolism-related genes. Abundance of PTEN decreased by 51.5% at peak lactation compared with the dry period. The PTEN was overexpressed in isolated GMEC through adenoviral transfection using an adenovirus system with Ad-GFP (recombinant adenovirus of green fluorescent protein) as control, and silenced via targeted small interfering RNA (siRNA) transfection with a scrambled small interfering RNA as a negative control. Cell culture was performed for 48 h before RNA extraction, triacylglycerol (TAG) analysis, and fatty acid analysis. Overexpression of PTEN downregulated abundance of acetyl-coenzyme A carboxylase α (ACACA), fatty acid synthase (FASN), sterol regulatory element binding transcription factor1 (SREBF1), stearoyl-coenzyme A desaturase 1 (SCD1), diacylglycerol acytransferase 1 (DGAT1), 1-acylglycerol-3-phosphate O-acyltransferase 6 (AGPAT6) coupled with an increase in patatin-like-phospholipase domain containing 2 (PNPLA2), hormone-sensitive lipase (LIPE), and carnitine palmitoyltransferase 1 β (CPT1B). Furthermore, overexpressing PTEN in vitro resulted in a significant decrease in TAG concentration and concentration of C16:1. In contrast, interference of PTEN led to an opposite effect on lipid metabolism in GMEC. These changes suggested a shift from lipogenesis and esterification to lipolysis and fatty acid oxidation. Collectively, PTEN seems to play a role in monounsaturated fatty acids synthesis and lipid accumulation in GMEC.

Schistosoma japonicum Infection Leads to the Reprogramming of Glucose and Lipid Metabolism in the Colon of Mice.

The deposition of Schistosoma japonicum (S. japonicum) eggs commonly induces inflammation, fibrosis, hyperplasia, ulceration, and polyposis in the colon, which poses a serious threat to human health. However, the underlying mechanism is largely neglected. Recently, the disorder of glucose and lipid metabolism was reported to participate in the liver fibrosis induced by the parasite, which provides a novel clue for studying the underlying mechanism of the intestinal pathology of the disease. This study focused on the metabolic reprogramming profiles of glucose and lipid in the colon of mice infected by S. japonicum. We found that S. japonicum infection shortened the colonic length, impaired intestinal integrity, induced egg-granuloma formation, and increased colonic inflammation. The expression of key enzymes involved in the pathways regulating glucose and lipid metabolism was upregulated in the colon of infected mice. Conversely, phosphatase and tensin homolog deleted on chromosome ten (PTEN) and its downstream signaling targets were significantly inhibited after infection. In line with these results, in vitro stimulation with soluble egg antigens (SEA) downregulated the expression of PTEN in CT-26 cells and induced metabolic alterations similar to that observed under in vivo results. Moreover, PTEN over-expression prevented the reprogramming of glucose and lipid metabolism induced by SEA in CT-26 cells. Overall, the present study showed that S. japonicum infection induces the reprogramming of glucose and lipid metabolism in the colon of mice, and PTEN may play a vital role in mediating this metabolic reprogramming. These findings provide a novel insight into the pathogenicity of S. japonicum in hosts.

LncRNA TRHDE-AS1 inhibit the scar fibroblasts proliferation via miR-181a-5p/PTEN axis

Hypertrophic scar (HS), a fibroproliferative disorder caused by abnormal wound healing after skin injury, which is characterized by excessive deposition of extracellular matrix and invasive growth of fibroblasts. Recent studies have shown that some non-coding RNA implicated the formation of HS, but the mechanism remains unclear. In this study, we found that lncRNA TRHDE-AS1 was downregulated in HS tissues and HSFs, and the level of lncRNA TRHDE-AS1 negatively correlated with the level of miR-181a-5p in HS tissue and HSFs. Overexpressed lncRNA TRHDE-AS1 significantly suppressed miR-181a-5p level, while promoted HSFs apoptosis and inhibited HSFs proliferation. Further study shown that PTEN was a direct target of miR-181a-5p, and lncRNA TRHDE-AS1 served as a molecular sponge for miR-181a-5p to regulate the expression of PTEN. Overexpression of PTEN could eliminate lncRNA TRHDE-AS1-mediated proliferation suppression of HSFs. In conclusion, our study suggested that lncRNA TRHDE-AS1/miR-181a-5p/PTEN axis plays an important role in promoting hypertrophic scar formation, which may be effectively used as a therapeutic target for hypertrophic scar treatment.

Hepatic HuR protects against the pathogenesis of non-alcoholic fatty liver disease by targeting PTEN

The liver plays an important role in lipid and glucose metabolism. Here, we show the role of human antigen R (HuR), an RNA regulator protein, in hepatocyte steatosis and glucose metabolism. We investigated the level of HuR in the liver of mice fed a normal chow diet (NCD) and a high-fat diet (HFD). HuR was downregulated in the livers of HFD-fed mice. Liver-specific HuR knockout (HuRLKO) mice showed exacerbated HFD-induced hepatic steatosis along with enhanced glucose tolerance as compared with control mice. Mechanistically, HuR could bind to the adenylate uridylate-rich elements of phosphatase and tensin homolog deleted on the chromosome 10 (PTEN) mRNA 3′ untranslated region, resulting in the increased stability of Pten mRNA; genetic knockdown of HuR decreased the expression of PTEN. Finally, lentiviral overexpression of PTEN alleviated the development of hepatic steatosis in HuRLKO mice in vivo. Overall, HuR regulates lipid and glucose metabolism by targeting PTEN.

MiR-26b regulates cell proliferation and apoptosis of CD117+CD44+ ovarian cancer stem cells by targeting PTEN.

Ovarian cancer (OC) is the one of the most common cancer in women globally. However, it still represents the most dangerous gynecologic malignancy even with the advances in detection and therapeutics. Thus, there is an urgent need in finding more effective therapeutic options for OC patients including cancer stem cells (CSC). MicroRNAs (miRNAs) are small, endogenous, and non-coding RNAs that play critical roles in the progression of various types of tumor. Our aim of this study was to find the regulatory function of microRNA-26 (miRNA- 26b) on the cell proliferation and apoptosis of ovarian CSCs. Our studies show that miR-26b is under-regulated in human CD117+CD44+ ovarian CSCs. The miR-26b overexpression inhibits the cell proliferation and promotes cell apoptosis. Moreover, phosphatase and tensin homolog (PTEN) is found to be a functional target of miR-26b. Moreover, PTEN overexpression reversed the effects of miR-26b on cell proliferation and apoptosis. PTEN overexpression remarkably accelerated cell proliferation, and inhibited cell apoptosis. These results indicate that MiR-26b regulates cell proliferation and apoptosis of CD117+CD44+ ovarian CSCs by targeting PTEN.

Critical implication of the PTEN/PI3K/AKT pathway during BMP2-induced heterotopic ossification

Heterotopic ossification (HO) is characterized by extraskeletal ossification in soft tissue. Thus far, there is a lack of effective drug therapy against HO. Loss of PTEN in osteoblasts has been reported to accumulate bone mass in skeletal development and promote fracture healing in association with the activation of the PI3K/AKT pathway. However, the role of the PTEN/PI3K/AKT signaling in HO pathogenesis remains unknown. The present study investigated the implication of this pathway during BMP2-induced osteogenic differentiation and ectopic bone formation. It was shown that overexpression of PTEN inhibited proliferation but stimulated apoptosis in mesenchymal pluripotent C3H10T1/2 cells. PTEN also inhibited BMP2-induced osteoblast differentiation, whereas BMP2 repressed PTEN expression and subsequently activated PI3K/AKT. The PI3K inhibitor, LY294002, blocked BMP2-induced osteoblastogenesis, suggesting that the PI3K/AKT pathway is critically required for BMP2 to initiate osteoblastogenesis. In vivo, implantation of BMP2 in muscle induced ectopic endochondral ossification. Strikingly, this bone-forming capacity was notably suppressed by the PI3K inhibitor LY294002. Hence, the results of the present study demonstrated that the PI3K/AKT signaling activity is indispensable for BMP2 to induce ectopic new bone. Targeting the PI3K/AKT pathway using inhibitor(s) may represent a potential molecular therapy for the treatment against HO.

MiR-139-5p promotes neovascularization in diabetic retinopathy by regulating the phosphatase and tensin homolog.

Pathological retinal neovascularization is a driver of the progression of diabetic retinopathy (DR). The present study sought to identify the microRNAs (miRNAs) that are differentially expressed during the progression of DR as well as to explore the specific regulatory mechanism of those miRNAs in retinal neovascularization. Using a microarray data set and a diabetic mouse model, it was determined that miR-139-5p was significantly upregulated during the progression of DR. The in vitro investigation revealed an elevation in the miR-139-5p level in both the high glucose (HG)-treated mouse retinal microvascular endothelial cells (mRMECs) and the HG-treated human RMECs (hRMECs). The miR-139-5p overexpression elevated cell migration, facilitated tube formation, and increased vascular endothelial growth factor (VEGF) protein level in the hRMECs. While the angiogenic effect of miR-139-5p overexpression was halted by an anti-VEGF antibody. Meanwhile, the miR-139-5p knockdown eliminated the VEGF-induced cell migration and tube formation in the hRMECs. The phosphatase and tensin homolog (PTEN) was the target gene of the miR-139-5p. PTEN overexpression removed the angiogenic effect of miR-139-5p overexpression, which led to reduced cell migration and tube formation. In the diabetic mice, the miR-139-5p antagomir effectively decreased the acellular capillaries and suppressed the formation of aberrant blood vessels in the retinal tissues. Taken together, miR-139-5p promotes retinal neovascularization by repressing PTEN expression.

Downregulated exosomal microRNA-148b-3p in cancer associated fibroblasts enhance chemosensitivity of bladder cancer cells by downregulating the Wnt/\u03b2-catenin pathway and upregulating PTEN

ObjectiveExosomes derived from cancer-associated fibroblasts (CAFs) are known as important drivers of tumor progression. Previously, microRNA (miR)-148b-3p has been found to be upregulated in bladder cancers as well as in body fluids (blood, urine) of bladder cancer patients. Here, we aimed to explore the role of CAF-derived exosome miR-148b-3p in bladder cancer progression and chemosensitivity.MethodsTranswell, MTT, flow cytometry and colony formation assays were applied to assess the effects of CAF-derived exosomes on bladder cancer cell metastasis, epithelial-mesenchymal transition (EMT) and chemosensitivity. A dual luciferase reporter assay was employed to evaluate the targeting relationship between miR-148b-3p and PTEN. Gain- and loss- of function assays were conducted to explore the roles of miR-148b-3p and PTEN in the behavior of bladder cancer cells. The role of PTEN in the metastasis, EMT and chemosensitivity of bladder cancer cells was assessed both in vivo and in vitro.ResultsWe found that CAF-derived exosomes promoted the metastasis, EMT and drug resistance of bladder cancer cells. We also found that CAF-derived exosomes could directly transport miR-148b-3p into bladder cancer cells. In a xenograft mouse model we found that CAF-derived exosomes increased miR-148b-3p expression levels and promoted tumor proliferation, metastasis and drug resistance. PTEN was validated as a target of miR-148b-3p. Concordantly, we found that PTEN overexpression inhibited EMT, metastasis and chemoresistance in bladder cancer cells, reversing the tumor promoting effects of miR-148b-3p via the Wnt/β-catenin pathway.ConclusionsOur results suggest that miR-148b-3p downregulation in CAF-derived exosomes, thereby inhibiting the Wnt/β-catenin pathway and promoting PTEN expression, may offer potential opportunities for bladder cancer treatment.

LncRNA PCAT29 Up-Regulates the Expression of PTEN by Down-Regulating miR-494 in Non-Small-Cell Lung Cancer to Suppress Tumor Progression.

PCAT29 has reported to exert tumor suppressive roles. In this study, we investigated the function of PCAT29 in non-small-cell lung cancer (NSCLC). Expression levels of PCAT29, miR-494, and PTEN in non-tumor and NSCLC tumor tissue samples were measured by performing quantitative reverse transcription polymerase chain reaction. Cell apoptosis and proliferation analyses were formed to study the effects of overexpression of PCAT29, miR-494, and PTEN on apoptosis and proliferation of H23 cells. It was observed that PCAT29 was down-regulated in NSCLC and predicted poor survival. In NSCLC cells, miR-494 was inversely, while PTEN was positively correlated with PCAT29. In NSCLC cells, overexpression of PCAT29 led to down-regulated miR-494 and up-regulated PTEN. Overexpression of miR-494 resulted in down-regulated PTEN but did not affect the expression of PCAT29. Overexpression of PTEN affected neither PCAT29 nor miR-494. In addition, overexpression of PCAT29 and PTEN resulted in increased apop-totic rate and decreased proliferation of NSCLC cells. miR-494 played an opposite role and attenuated the effects of overexpression of PCAT29. Therefore, PCAT29 may up-regulate PTEN by down-regulating miR-494 to suppress the progression of NSCLC cells.