Silencing lncRNA LINC01410 suppresses cell viability yet promotes apoptosis and sensitivity to temozolomide in glioblastoma cells by inactivating PTEN/AKT pathway via targeting miR-370-3p

BACKGROUND

Long non-coding RNAs (LncRNAs) are involved in glioblastoma (GBM), but the role of long intergenic non-protein coding RNA 01410 (lncRNA LINC01410) is poorly understood.

METHODS

The expression of LINC01410 in GBM tissues and cells was analyzed. After transfection or temozolomide (TMZ) treatment, the cell viability and apoptosis were detected using cell counting kit-8 assay and flow cytometry. The targeting relationship between LINC01410 and microRNA (miR)-370-3p was confirmed by dual-luciferase reporter assay. Expressions of LINC01410, miR-370-3p and drug resistance- and Phosphatase and Tensin Homolog (PTEN)/AKT pathway-related factors were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot.

RESULTS

LINC01410 expression was upregulated in GBM, and silencing of LINC01410 decreased cell viability. A slowed decreased trend in cell viability yet an increased half maximal inhibitory concentration (IC50 for TMZ) value and increased expressions of drug resistance-related factors as well as LINC01410 were found in TMZ-resistant GBM cells. Silencing of LINC01410 also decreased the IC50 value yet promoted the sensitivity and apoptosis in TMZ-resistant cells, while upregulating the expression of PTEN and downregulating the phosphorylation of AKT. MiR-370-3p could competitively bind to LINC01410 and its expression was decreased in both parental and TMZ-resistant GBM cells. Downregulation of miR-370-3p reversed the effects of LINC01410 silencing on cell viability, apoptosis and the expressions of miR-370-3p and PTEN/AKT pathway-related factors.

CONCLUSION

Silencing of LINC01410 inhibits cell viability yet enhances apoptosis and sensitivity to TMZ in GBM cells by inactivating PTEN/AKT pathway via targeting miR-370-3p.

Berberine regulates the Notch1/PTEN/PI3K/AKT/mTOR pathway and acts synergistically with 17-AAG and SAHA in SW480 colon cancer cells

CONTEXT

Berberine (BBR) is used to treat diarrhoea and gastroenteritis in the clinic. It was found to have anticolon cancer effects.

OBJECTIVE

To study the anticolon cancer mechanism of BBR by connectivity map (CMAP) analysis.

MATERIALS AND METHODS

CMAP based mechanistic prediction was conducted by comparing gene expression profiles of 10 μM BBR treated MCF-7 cells with that of clinical drugs such as helveticoside, ianatoside C, pyrvinium, gossypol and trifluoperazine. The treatment time was 12 h and two biological replications were performed. The DMSO-treated cells were selected as a control. The interaction between 100 μM BBR and target protein was measured by cellular thermal shift assay. The protein expression of 1-9 μM BBR treated SW480 cells were measured by WB assay. Apoptosis, cell cycle arrest, mitochondrial membrane potential (MMP) of 1-9 μM BBR treated SW480 cells were measured by flow cytometry and Hoechst 33342 staining methods.

RESULTS

CMAP analysis found 14 Hsp90, HDAC, PI3K or mTOR protein inhibitors have similar functions with BBR. The experiments showed that BBR inhibited SW480 cells proliferation with IC₅₀ of 3.436 μM, induced apoptosis, autophage, MMP depolarization and arrested G1 phase of cell cycle at 1.0 μM. BBR dose-dependently up-regulated PTEN, while inhibited Notch1, PI3K, Akt and mTOR proteins at 1.0-9.0 μM (p < 0.05). BBR also acted synergistically with Hsp90 and HDAC inhibitor (0.01 μM) in SW480 cells at 0.5 and 1.0 μM.

DISCUSSION AND CONCLUSIONS

The integrative gene expression-based chemical genomic method using CMAP analysis may be applicable for mechanistic studies of other multi-targets drugs.

TUBB3 is associated with PTEN, neuroendocrine differentiation, and castration resistance in prostate cancer

BACKGROUND

Tubulin-β3 encoded by the Tubulin-β3 (TUBB3) gene is a microtubule protein. Previous studies have shown that TUBB3 expression is upregulated in castration-resistant prostate cancer (CaP) and is involved in taxane resistance. However, the biological mechanism of TUBB3 involvement in the progression to castration-resistant CaP is not fully elucidated. This study aimed to analyze the expression and function of TUBB3 in localized and metastatic CaP.

METHODS

TUBB3 expression was determined using immunohistochemistry in localized and metastatic CaP. We also investigated the association between TUBB3, phosphatase and tensin homolog (PTEN), and neuroendocrine differentiation and examined the involvement of TUBB3 in new antiandrogen drugs (enzalutamide and apalutamide) resistance in metastatic CaP.

RESULTS

In 155 cases of localized CaP, immunohistochemistry showed that 5 (3.2%) of the CaP cases were positive for tubulin-β3. Kaplan-Meier analysis showed that high expression of tubulin-β3 was associated with poor prostate-specific antigen recurrence-free survival after radical prostatectomy. In 57 cases of metastatic CaP, immunohistochemistry showed that 14 (25%) cases were positive for tubulin-β3. Tubulin-β3 expression was higher in metastatic CaP than in localized CaP. High tubulin-β3 expression was correlated with negative PTEN expression. TUBB3 expression was increased in neuroendocrine CaP based on several public databases. PTEN knockout decreased the sensitivity to enzalutamide and apalutamide in 22Rv-1 cells. TUBB3 knockdown reversed the sensitivity to enzalutamide and apalutamide in PTEN-CRISPR 22Rv-1 cells. High expression of tubulin-β3 and negative expression of PTEN were significantly associated with poor overall survival in metastatic CaP treated with androgen deprivation therapy.

CONCLUSIONS

These results suggest that TUBB3 may be a useful predictive biomarker for survival and play an essential role in antiandrogen resistance in CaP.

MicroRNA-144 promotes remote limb ischemic preconditioning-mediated neuroprotection against ischemic stroke via PTEN/Akt pathway

Ischemic stroke is a refractory disease generally caused by cerebral ischemic injury. Remote ischemic preconditioning (RIPC) caused by transient ischemia and reperfusion of the femoral artery exerts a protective effect on ischemic stroke-induced brain injury. This study was designed to investigate the potential molecular mechanism of RIPC-mediated neuroprotection, namely, the biological effects of microRNA-144 on RIPC in mice with ischemic stroke and its effects on PTEN and Akt signaling pathways. Healthy adult C57BL6 mice were selected for the establishment of middle cerebral artery occlusion (MCAO). One hour before the start, remote ischemic preconditioning of limbs was performed in mice. Brain edema and infarct volume were measured. The expressions of microRNA-144, PTEN, and Akt were measured. The results showed that, compared with MCAO group, the RIPC group protected mice from cerebral ischemia-reperfusion injury, systemic accumulation of inflammatory cytokines, and accelerated apoptosis of parenchymal cells. In RIPC group, PTEN expression decreased, and mir-144 and Akt expression increased. The level of phosphorylated PTEN in the transfected microRNA-144 inhibitor group increased and the level of phosphorylated Akt reduced significantly. In conclusion, our results suggest that microRNA-144 may play a protective role in remote ischemic pretreatment by downregulating PTEN and upregulating Akt, suggesting that microRNA-144 via PTEN/Akt pathway may be of therapeutic significance in ischemic stroke.

WDHD1 is essential for the survival of PTEN-inactive triple-negative breast cancer

Triple-negative breast cancer (TNBC) is the most aggressive type of breast cancer that lacks the oestrogen receptor, progesterone receptor and human epidermal growth factor receptor 2, making it difficult to target therapeutically. Targeting synthetic lethality is an alternative approach for cancer treatment. TNBC shows frequent loss of phosphatase and tensin homologue (PTEN) expression, which is associated with poor prognosis and treatment response. To identify PTEN synthetic lethal interactions, TCGA analysis coupled with a whole-genome siRNA screen in isogenic PTEN-negative and -positive cells were performed. Among the candidate genes essential for the survival of PTEN-inactive TNBC cells, WDHD1 (WD repeat and high-mobility group box DNA-binding protein 1) expression was increased in the low vs. high PTEN TNBC samples. It was also the top hit in the siRNA screen and its knockdown significantly inhibited cell viability in PTEN-negative cells, which was further validated in 2D and 3D cultures. Mechanistically, WDHD1 is important to mediate a high demand of protein translation in PTEN-inactive TNBC. Finally, the importance of WDHD1 in TNBC was confirmed in patient samples obtained from the TCGA and tissue microarrays with clinic-pathological information. Taken together, as an essential gene for the survival of PTEN-inactive TNBC cells, WDHD1 could be a potential biomarker or a therapeutic target for TNBC.

PTEN and ERG expression in MRI-ultrasound guided fusion biopsy correlated with radical prostatectomy findings in men with prostate cancer

BACKGROUND

Conventional systematic prostate biopsies (SBx) have multiple limitations, and magnetic resonance imaging (MRI)-ultrasound fusion targeting is increasingly applied (fusion biopsies [FBx]). In our previous studies, we have shown that loss of the tumor suppressor gene phosphatase and tensin homolog (PTEN) in radical prostatectomy (RP) specimens predicts poor disease-specific survival, and in active surveillance (AS), PTEN loss in SBx predicts an adverse AS outcome, although SBx PTEN status does not correlate well with the corresponding RP status. Here, we have hypothesized that PTEN and erythroblast transformation-specific related gene (ERG) status in FBx correlate better with RP than they would in SBx.

METHODS

A total of 106 men, who had undergone FBx and subsequent RP in a single center between June 2015 and May 2017 were included. Fifty-three of the men had concomitant or previous SBx's. All biopsy and RP specimens were collected, and tissue microarrays (TMA) were constructed from RP specimens. Immunohistochemical stainings for PTEN and ERG expression were conducted on biopsies and RP TMAs and results were compared by using Fisher's exact test.

RESULTS

The immunohistochemical predictive power of FBx, determined by the concordance of biopsy PTEN and ERG status with RP, is superior to SBx (77.6% vs 66.7% in PTEN, 92.4% vs 66.6% in ERG). FBx was superior to SBx in correlation with RP Gleason Grade Groups and MRI prostate imaging reporting and data system scores.

CONCLUSION

FBx grading correlates with RP histology and MRI findings and predicts the biomarker status in the RP specimens more accurately than SBx. A longer follow-up is needed to evaluate if this translates to better prediction of disease outcomes, especially in AS and radiation therapy where prostatectomy specimens are not available for prognostication.

Clinical and pathological associations of PTEN expression in ovarian cancer: a multicentre study from the Ovarian Tumour Tissue Analysis Consortium

BACKGROUND

PTEN loss is a putative driver in histotypes of ovarian cancer (high-grade serous (HGSOC), endometrioid (ENOC), clear cell (CCOC), mucinous (MOC), low-grade serous (LGSOC)). We aimed to characterise PTEN expression as a biomarker in epithelial ovarian cancer in a large population-based study.

METHODS

Tumours from 5400 patients from a multicentre observational, prospective cohort study of the Ovarian Tumour Tissue Analysis Consortium were used to evaluate associations between immunohistochemical PTEN patterns and overall survival time, age, stage, grade, residual tumour, CD8+ tumour-infiltrating lymphocytes (TIL) counts, expression of oestrogen receptor (ER), progesterone receptor (PR) and androgen receptor (AR) by means of Cox proportional hazard models and generalised Cochran-Mantel-Haenszel tests.

RESULTS

Downregulation of cytoplasmic PTEN expression was most frequent in ENOC (most frequently in younger patients; p value = 0.0001) and CCOC and was associated with longer overall survival in HGSOC (hazard ratio: 0.78, 95% CI: 0.65-0.94, p value = 0.022). PTEN expression was associated with ER, PR and AR expression (p values: 0.0008, 0.062 and 0.0002, respectively) in HGSOC and with lower CD8 counts in CCOC (p value < 0.0001). Heterogeneous expression of PTEN was more prevalent in advanced HGSOC (p value = 0.019) and associated with higher CD8 counts (p value = 0.0016).

CONCLUSIONS

PTEN loss is a frequent driver in ovarian carcinoma associating distinctly with expression of hormonal receptors and CD8+ TIL counts in HGSOC and CCOC histotypes.

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.

MicroRNA-17-5p regulates the growth, migration and invasion of the human osteosarcoma cells by modulating the expression of PTEN

PURPOSE

Osteosarcoma causes extensive human mortality and there is urgent need to develop novel therapies or to identify efficient therapeutic targets for its management. Herein the role and therapeutic potential of miR-17 was explored in osteosarcoma.

METHODS

The normal hFOB.19 cell line and the osteosarcoma cell lines SAOS-2, HOS, 143B, T1-73 and mG63 were used in the present study. The expression analysis of miR-17 was carried out by quantitative Real-Time polymerase chain reaction (qRT-PCR). Lipofectamine 2000 reagent (Invitrogen, Carlsbad, CA, USA) was used for transfection. WST-1 assay was used for determination of cell proliferation and autophagy was detected by transmission electron microscopy (TEM). Wound healing and transwell assays were used for the determination of cell migration and invasion. Protein expression was determined by western blot analysis.

RESULTS

The expression of miR-17 was significantly elevated in all the osteosarcoma cells. Suppression of miR-17 resulted in decrease of the viability and colony formation of the SAOS-2 osteosarcoma cells. The inhibition of SAOS-2 cell proliferation upon miR-17 suppression was found to be due to induction of autophagy which was accompanied with enhancement in the expression of LC3B II and Beclin-1. Suppression of miR-17 was also accompanied by inhibition of the SAOS-2 cell migration and invasion. The in silico analysis showed that miR-187 targets PTEN in the SAOS-2 cells. The expression of PTEN was found to be downregulated in all the osteosarcoma cells and suppression of miR-17 expression caused enhancement in the expression of PTEN. Overexpression of miR-17 caused inhibition of the proliferation and colony formation of the SAOS-2 cells. Additionally, silencing of miR-17 could abolish the effects of miR-17 inhibition in the SAOS-2 cells.

CONCLUSION

MiR-17 may be proven a therapeutic target in the management of osteosarcoma.

Inhibition of PTEN Gene Expression by Small Interfering RNA on PI3K/Akt/FoxO3a Signaling Pathway in Human Nasopharyngeal Carcinoma

The objective of this article is to study the effect of inhibiting phosphatase and tensin homolog deleted chromatosome 10 gene on phosphoinositide 3-kinase/protein kinase B (Akt)/Forkhead homeobox O3a signaling pathway in human nasopharyngeal carcinoma HK-1 cells. Nasopharyngeal carcinoma HK-1 cell lines were divided into PTEN gene interference group (siPTEN), nonspecific small interfering RNA group (siNC), empty vector group (Vector), and no transfection control group (Normal). The mRNA and protein expression levels of PTEN, PI3K, p-Akt, and FoxO3a were detected by real-time fluorescence quantitative polymerase chain reaction and Western blot. Immunofluorescence was used to detect the subcellular localization of PTEN, PI3K, p-Akt, and FoxO3a in HK-1 cells. The proliferation of HK-1 cells was detected by MTT assay, and the apoptosis of HK-1 cells was detected by flow cytometry. Compared with the siNC group, the expression levels of PTEN, FoxO3a messenger RNA, and protein in the siPTEN group were significantly decreased (P < .05), while the expression levels of PI3K, p-Akt messenger RNA, and protein were significantly increased (P < .05). The growth rate of HK-1 cells in the siPTEN group was significantly higher than the siNC group (P < .05), while the apoptosis rate was significantly lower than that of the siNC group (P < .05). Small interfering RNA can inhibit the expression of PTEN in HK-1 cells, and PTEN can participate in the development of NPC by affecting PI3K/Akt/FoxO3a signaling pathway.

USP18 is a significant driver of memory CD4 T-cell reduced viability caused by type I IFN signaling during primary HIV-1 infection

The loss of Memory CD4 T-cells (Mem) is a major hallmark of HIV-1 immuno-pathogenesis and occurs early during the first months of primary infection. A lot of effort has been put into understanding the molecular mechanisms behind this loss, yet they still have not been fully identified. In this study, we unveil the unreported role of USP18 in the deleterious effects of sustained type I IFN signaling on Mem, including HIV-1-specific CD4 T-cells. We find that interfering with IFN-I signaling pathway in infected patients, notably by targeting the interferon-stimulated gene USP18, resulted in reduced PTEN expression similar to those observed in uninfected control donors. We show that AKT activation in response to cytokine treatment, T-cell receptor (TcR) triggering, as well as HIV-1 Gag stimulation was significantly improved in infected patients when PTEN or USP18 were inhibited. Finally, our data demonstrate that higher USP18 in Mem from infected patients prevent proper cell survival and long-lasting maintenance in an AKT-dependent manner. Altogether, we establish a direct role for type I IFN/USP18 signaling in the maintenance of total and virus-specific Mem and provide a new mechanism for the reduced survival of these populations during primary HIV-1 infection.

In this study, we expend our knowledge of how type I interferons (IFN-I) leads to memory CD4 T-cell defective survival by unveiling the molecular mechanism behind such impairments, placing USP18 at its center. Our data further deciphers the specific USP18-related mechanism that is responsible for such impairments by implicating AKT inhibition in a PTEN-dependent manner. Our findings also point to a potential use of neutralizing anti-interferon α/β receptor antibodies to rescue the defective memory CD4 T-cell survival during HIV-1 infection, even in HIV-1 specific CD4 T-cell. To conclude, our findings provide the characterization of the molecular pathway leading to disturbances caused by sustained IFN-I signaling which occurs early during primary HIV-1 infection, complementing current knowledge which placed sustained IFN-I signaling as detrimental to the host during this infection.

Evaluation of PTEN and CD4+FOXP3+ T cell expressions as diagnostic and predictive factors in endometrial cancer: A case control study

To evaluate the potential role of Pten and CD4FOXP3 T cells in prognosis from endometrial cancer.Tissue samples and clinical data were collected from 200 patients with endometrial cancer and 100 control patients with benign uterine diseases. The expressions of Pten and CD4FOXP3 T cells were quantified by immunohistochemistry and immunofluorescence. After surgery, all patients were followed up for an average of 56.3 months. Surgical effects were evaluated based on the patients' symptoms and signs. A two-sided P value < .05 was considered significant.Pten diminished and CD4FOXP3 T cells significantly accumulated with the progression of endometial cancer, in comparison to the controls. Moreover, Pten expression was negatively correlated with the count of CD4FOXP3 T cells. Pten and CD4FOXP3 T cells were correlated with clinical characteristics, including tumor stage, differentiation and associated with patients' disease-free survival.Limited data were available between the expressions of Pten and CD4FOXP3 T cells in patients with endometrial cancer. Our study findings suggested that the expressions of Pten and CD4FOXP3 T cells might become possible biomarkers for the diagnosis and prediction in endometrial cancer.

Differential response to neoadjuvant hormonal therapy in prostate cancer: Predictive morphological parameters and molecular markers

OBJECTIVES

The predictive value of the histological parameters and molecular markers for neoadjuvant hormonal therapy (NHT) in prostate cancer (PCa) has not been well established. The aim of this study is to determine pathological variables that can predict differences in response to NHT in PCa.

METHODS

A total of 85 locally high risk PCa patients with matched preoperative needle biopsies and radical prostatectomy (RP) specimens were included. All patients were treated with NHT for at least 3 months. We quantified the response to NHT using a new proposed pathological grading system. The system classified tumors into five groups (grades 0-4) according to the severity of histological response. We then categorized the PCa patients into drug-sensitive (DS) group (Grades 2-4) and drug-resistant (DR) group (Grades 0-1). Two pathologists assessed each pretreated tumors for presence or absence of nine morphological features. The expression of androgen receptor (AR), ERG, and PTEN were evaluated by immunohistochemistry (IHC) as well. Statistical analysis was performed to identify significant associations between differentially histological response to NHT and morphological features as well as molecular aberrations. We evaluated different prediction models using receiver operating characteristic (ROC) curves and area under the ROC curve (AUC) analysis.

RESULTS

73% (n = 62/85) of tumors in our cohort belonged to DS group, whereas 27% (n = 23/85) of tumors were DR. Univariate logistic analysis suggested four pathological variables, cribriform growth pattern, macronucleoli, ductal adenocarcinoma differentiation, and PTEN loss in needle biopsies were significantly associated with DR effect, all with P-value < 0.05. Multivariate logistic regression analysis revealed that the three parameters as significant predictive factors for predicting DR effect. These were macronucleoli (RR = 4.008, P = 0.002), ductal adenocarcinoma differentiation (RR = 11.659, P = 0.009) and PTEN loss expression (RR = 7.275, P = 0.015). The AUC of three integrated indicators model was 0.781.

CONCLUSIONS

Our study suggested that the presence of tumor cribriform growth pattern, macronucleoli, ductal adenocarcinoma differentiation, and PTEN loss in needle biopsies are of value in predicting tumor response to NHT regimen. Multivariate logistic regression analysis revealed the performance of combined pathological indicators in predicting DR response was better than that of model based on individual factor alone.

MicroRNA-19a promotes proliferative and migratory abilities of NSCLC cells by inhibiting PTEN expression

PURPOSE

To investigate whether microRNA-19a can promote the proliferative and migratory abilities of non-small cell lung cancer (NSCLC) cells by target inhibition of PTEN (phosphatase and tensin homolog deleted from chromosome 10, PTEN) expression, thus leading to the development of NSCLC.

METHODS

The expression level of microRNA-19a in NSCLC tissues, paracancerous tissues and normal lung tissues was detected by quantitative real time-polymerase chain reaction (qRT-PCR). The regulatory effects of microRNA-19a on proliferative and migratory abilities of NSCLC cells were determined by cell counting kit-8 (CCK-8), colony formation assay and Transwell assay, respectively. The binding condition between microRNA-19a and PTEN was verified by dual-luciferase reporter gene assay. PTEN expression in NSCLC cells transfected with microRNA-19a mimic or inhibitor was detected by Western blot. Rescue experiments were conducted by co-transfection of microRNA-19a mimic and pcDNA-PTEN in NSCLC cells, followed by detection of cell proliferation, colony formation and migration.

RESULTS

QRT-PCR data showed higher expression of microRNA-19a in NSCLC tissues and cell lines than that of controls. Overexpression of microRNA-19a in NSCLC A549 and H1299 cell lines promoted proliferative and migratory abilities. Dual-luciferase reporter gene assay confirmed the binding site between microRNA-19a and PTEN. PTEN expression was negatively regulated by microRNA-19a both at mRNA and protein levels. Rescue experiments showed that PTEN overexpression could partially reverse the regulatory effects of microRNA-19a on promoting proliferative and migratory abilities of NSCLC cells.

CONCLUSIONS

Higher expression of microRNA-19a promotes proliferative and migratory abilities of NSCLC cells by target inhibiting PTEN expression.

Preliminary results indicate resveratrol affects proliferation and apoptosis of leukemia cells by regulating PTEN/PI3K/AKT pathway

OBJECTIVE

PTEN-PI3K/AKT signaling pathway is widely involved in the regulation of cell proliferation, cell cycle, apoptosis, and invasion. Resveratrol (Resv) is a natural botanical ingredient involved in several biological activities. It is still unclear in terms of whether Resv may exert anti-leukemia effects by regulating the PTEN-PI3K/AKT pathway. This study investigated the effect of Resv on leukemia cell proliferation and apoptosis by regulating PTEN-PI3K/AKT pathway.

PATIENTS AND METHODS

Human normal peripheral blood PBMC cells, and human acute promyelocytic leukemia (APL) cell line NB-4 and HL-60 cells were cultured in vitro. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect Phosphatase and tensin homolog (PTEN) mRNA expression. Western blot was adopted to test PTEN protein expression. HL-60 and NB-4 cells were treated with 0, 5, 10, and 20 μM Resv, respectively. Cell proliferation was analyzed by cell counting kit8 (CCK-8) assay. The level of caspase-3 was measured by Western blot. HL-60 cells were divided into control group, 20 μM Resv treatment group, and Resv+PTEN inhibitor SF1670 group. Cell apoptosis was determined by flow cytometry. Cell proliferation was assessed by EdU staining.

RESULTS

Compared with peripheral blood mononuclear cell (PBMC), PTEN mRNA and protein levels were significantly decreased in NB-4 and HL-60 cells. Resv significantly inhibited the proliferation activity in HL-60 and NB-4 cells, and increased the activity of caspase-3. Resv treatment up-regulated the expression of PTEN and reduced the expression of p-AKT protein in HL-60 cells. However, Resv treatment markedly suppressed the proliferation of HL-60 and induced apoptosis. SF1670 treatment in the presence of Resv significantly antagonized the down-regulation of p-AKT protein expression induced by Resv, resulting in decreased apoptosis and enhanced cell proliferation.

CONCLUSIONS

Resv can up-regulate PTEN expression and inhibit the activity of PI3K/AKT pathway to play an anti-leukemia effect through suppressing cell proliferation and inducing apoptosis.

The role of the phosphatase and tensin homolog status in predicting pathological complete response to neoadjuvant anti-HER2 therapies in HER2-positive primary breast cancer: A meta-analysis

PURPOSE

The addition of anti-HER2 therapies to neoadjuvant treatment significantly enhances pathological complete response (PCR) rate in patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer. Selecting patients unlikely to benefit from neoadjuvant anti-HER2 therapies is increasingly important. In this study, we proposed to assess the role of the phosphatase and tensin homolog (PTEN) as a biomarker in predicting PCR to neoadjuvant anti-HER2 therapies by conducting meta-analysis.

METHODS

Our team searched Embase, Medline, and the Cochrane Library by the end of September 16, 2018, for trials on patients with HER2-positive breast cancer treated with neoadjuvant anti-HER2 therapies. The associations between PTEN expression and PCR rate were then assessed. Odds ratio (ORs) and hazard ratio (HRs) with 95% confidence intervals (CIs) with 2-sided P values were calculated. The Newcastle-Ottawa scale (NOS) was used to estimate the quality of the involved trials.

RESULTS

A total of 820 patients from 8 trials were included in this meta-analysis. Overall, the PTEN normal tumors was related to a significant increase in PCR rate (OR 0.55; 95% CI = 0.31-0.96; P = .04; I = 54%). In different anti-HER2 agents analysis, the PTEN normal tumors was related to a significant increase in PCR rate in patients treated with trastuzumab alone (OR 0.40; 95% CI = 0.24-0.67; P = .0005; I = 15%). Besides, no significant association between PTEN status and PCR rate was detected in patients treated with lapatinib alone (OR 1.90; 95% CI = 0.78-4.60; P = .16; I = 0%) or trastuzumab plus lapatinib (OR 1.27; 95% CI = 0.27-5.97; P = .76; I = 73%).

CONCLUSION

Based on current evidence, PTEN status could be n suitable biomarker in predicting PCR rate to neoadjuvant anti-HER2 therapies, especially in trastuzumab-treated patients.

Concomitant p53 and PTEN immunoexpression to predict the risk of malignancy in endometrial polyps

The aim of this retrospective cross-sectional study was to assess the usefulness of phosphase and tensin homolog deleted on chromosome 10 (PTEN) and p53 protein immunoexpression in predicting the risk of malignancy in endometrial polyps. The study was conducted at tertiary public hospital, university teaching center, and private practice clinic.A total of 159 patients with endometrial polyps who underwent hysteroscopic polypectomy between January 2010 to December 2014 were included. p53 and PTEN immunoexpression were assessed in histologic endometrial polyp samples. Patients were allocated into 2 groups: group A, endometrial polyps without atypia (120), and group B, endometrial polyps with atypia (39), which were subdivided into A1 (80) and B1 (21) = p53-/PTEN+ immunostaining; A2 (20) and B2 (11) = p53+/PTEN+; A3 (14) and B3 (4) = p53+/PTEN-; A4 (6) and B4 (3) = p53-/PTEN-.There was no significant difference between groups regarding clinical and epidemiologic parameters, except for age. Neoplasia incidence within groups was higher when at least 1 marker was abnormally stained (in group A, P = .0089, odds ratio [OR] = 13.94 [1.62; 120.27]; in group B, P = .0255, OR 12.73 [1.38; 117.27]). Overall neoplasia incidence was higher in group B than in group A (20.5% vs 5.8%; P = .0113). Malignant neoplasia was found more frequently in patients with p53+ (P = .0006, OR = 7.67 [2.30; 25.54]) and PTEN- (P = .0043; OR = 5.43 [1.77; 16.61]).Immunohistochemical analysis using p53 and PTEN as markers, either alone or concomitantly, can be useful to predict malignant transformation in cases of endometrial polyps.

Clinical utility of assessing PTEN and ERG protein expression in prostate cancer patients: a proposed method for risk stratification

OBJECTIVES

To assess the prognostic value of ERG and PTEN protein expression as two of the most common genetic aberration in men with prostate cancer managed non-surgically by androgen deprivation therapy (ADT).

MATERIALS AND METHODS

463 tumor samples were assessed by double immunohistochemistry stains for ERG and PTEN and data correlated with clinical pathological features including, Gleason score, patients' outcome and ADT.

RESULTS

ERG expression and PTEN protein loss were present in 28.2% and 38% of total patients respectively. There was a significant interplay between ERG and PTEN expression with 21.8% PTEN negative tumors being ERG positive (p < 0.001). Both ERG and PTEN showed significant association with lethal disease in all patients and those treated with prior ADT representing castrate-resistant disease. However, only PTEN remained significant in multivariable proportional hazards regression analysis, when including Gleason score and patients' age. Depending on patient's subgroup, intact positive PTEN intensity showed better cancer-specific survival with HR ranging from 0.25 to 0.4 compared to tumors with loss of PTEN expression. Assessing combined marker status, patients with decreased PTEN intensity without ERG positivity showed the worst clinical outcome compared to those with no PTEN loss and no ERG expression, where they had best clinical outcome. Patients with ERG expression with or without PTEN loss showed intermediate risk in relation to lethal disease.

CONCLUSION

This study confirms a significant prognostic role for assessing ERG and PTEN in men with prostate cancer. It supports a role for utilizing combined ERG/PTEN status clinically and prospectively for stratifying PCa patients into different prognostic groups.

The influence of PTEN protein expression on disease outcome in premenopausal hormone receptor-positive early breast cancer patients treated with adjuvant ovarian ablation: a long-term follow-up

PURPOSE

All breast cancer (BC) patients with detectable hormone receptors (HR) expression should be offered endocrine therapy (ET). In premenopausal patients, tamoxifen and/or ovarian suppression (OvS)/ablation (OA) may improve disease outcome. Alteration of phosphatase and tensin homolog (PTEN) signaling pathways could be one of the possible mechanisms of resistance to antiestrogen therapy. The purpose of this study was to investigate the association of PTEN protein expression with prognostic factors such as tumor histology and grade, estrogen receptor (ER) and progesterone receptor (PgR) status, human epidermal growth factor receptor 2 (HER2) and disease outcome in premenopausal patients with HR-positive early BCs treated with adjuvant OA.

METHODS

We analyzed a group of premenopausal early stages I/II HR-positive BC patients who had undergone radical mastectomy followed only with adjuvant OA by irradiation. ER and PgR contents were determined by classical biochemical dextran-coated charcoal (DCC) method, HER2 status by chromogen in situ hybridization (CISH) analysis and PTEN status by immunohistochemistry (IHC).

RESULTS

Sixty-six premenopausal patients included into this analysis were followed for a median of 17 years (range 17-29). Compared to PTEN-positive BCs, PTEN-negative BCs were significantly more frequently associated with lobular tumor histology (p<0.05), higher ER content (p<0.05), and had significantly decreased disease-free survival (DFS) and overall survival (OS) (p<0.01 for both) compared to patients with PTEN-positive BCs.

CONCLUSIONS

It seems that PTEN status determined by protein expression may discriminate between subgroups with poor and good prognosis in premenopausal HR-positive BC patients receiving adjuvant OA.

Niclosamide Exhibits Potent Anticancer Activity and Synergizes with Sorafenib in Human Renal Cell Cancer Cells

BACKGROUND/AIMS

As the most lethal urological cancers, renal cell carcinoma (RCC) comprises a heterogeneous group of cancer with diverse genetic and molecular alterations. There is an unmet clinical need to develop efficacious therapeutics for advanced, metastatic and/or relapsed RCC. Here, we investigate whether anthelmintic drug Niclosamide exhibits anticancer activity and synergizes with targeted therapy Sorafenib in suppressing RCC cell proliferation.

METHODS

Cell proliferation and migration were assessed by Crystal violet staining, WST-1 assay, cell wounding and cell cycle analysis. Gene expression was assessed by qPCR. In vivo anticancer activity was assessed in xenograft tumor model.

RESULTS

We find that Niclosamide effectively inhibits cell proliferation, cell migration and cell cycle progression, and induces apoptosis in human renal cancer cells. Mechanistically, Niclosamide inhibits the expression of C-MYC and E2F1 while inducing the expression of PTEN in RCC cells. Niclosamide is further shown to synergize with Sorafenib in suppressing RCC cell proliferation and survival. In the xenograft tumor model, Niclosamide is shown to effectively inhibit tumor growth and suppress RCC cell proliferation.

CONCLUSIONS

Niclosamide may be repurposed as a potent anticancer agent, which can potentiate the anticancer activity of the other agents targeting different signaling pathways in the treatment of human RCC.

Shikonin suppresses proliferation and induces apoptosis in endometrioid endometrial cancer cells via modulating miR-106b/PTEN/AKT/mTOR signaling pathway

Shikonin, a natural naphthoquinone isolated from a traditional Chinese medicinal herb, which exerts anticancer effects in various cancers. However, the molecular mechanisms underlying the therapeutic effects of shikonin against endometrioid endometrial cancer (EEC) have not yet been fully elucidated. Herein, we investigated anticancer effects of shikonin on EEC cells and explored the underlying molecular mechanism. We observed that shikonin inhibits proliferation in human EEC cell lines in a dose-dependent manner. Moreover, shikonin-induced apoptosis was characterized by the up-regulation of the pro-apoptotic proteins cleaved-Caspase-3 and Bax, and the down-regulation of the anti-apoptotic protein Bcl-2. Microarray analyses demonstrated that shikonin induces many miRNAs' dysregulation, and miR-106b was one of the miRNAs being most significantly down-regulated. miR-106b was identified to exert procancer effect in various cancers, but in EEC remains unclear. We first confirmed that miR-106b is up-regulated in EEC tissues and cells, and knockdown of miR-106b suppresses proliferation and promotes apoptosis. Meanwhile, our results validated that the restored expression of miR-106b abrogates the antiproliferative and pro-apoptotic effects of shikonin. We also identified that miR-106b targets phosphatase and tensin homolog (PTEN), a tumor suppressor gene, which in turn modulates AKT/mTOR signaling pathway. Our findings indicated that shikonin inhibits proliferation and promotes apoptosis in human EEC cells by modulating the miR-106b/PTEN/AKT/mTOR signaling pathway, suggesting shikonin could act a potential therapeutic agent in the EEC treatment.

Differential role of PTEN in transforming growth factor β (TGF-β) effects on proliferation and migration in prostate cancer cells

BACKGROUND

Transforming growth factor-β (TGF-β) acts as a tumor suppressor in normal epithelial cells but as a tumor promoter in advanced prostate cancer cells. PI3-kinase pathway mediates TGF-β effects on prostate cancer cell migration and invasion. PTEN inhibits PI3-kinase pathway and is frequently mutated in prostate cancers. We investigated possible role(s) of PTEN in TGF-β effects on proliferation and migration in prostate cancer cells.

METHODS

Expression of PTEN mRNA and proteins were determined using RT-PCR and Western blotting in RWPE1 and DU145 cells. We also studied the role of PTEN in TGF-β effects on cell proliferation and migration in DU145 cells after transient silencing of endogenous PTEN. Conversely, we determined the role of PTEN in cell proliferation and migration after over-expression of PTEN in PC3 cells which lack endogenous PTEN.

RESULTS

TGF-β1 and TGF-β3 had no effect on PTEN mRNA levels but both isoforms increased PTEN protein levels in DU145 and RWPE1 cells indicating that PTEN may mediate TGF-β effects on cell proliferation. Knockdown of PTEN in DU145 cells resulted in significant increase in cell proliferation which was not affected by TGF-β isoforms. PTEN overexpression in PC3 cells inhibited cell proliferation. Knockdown of endogenous PTEN enhanced cell migration in DU145 cells, whereas PTEN overexpression reduced migration in PC3 cells and reduced phosphorylation of AKT in response to TGF-β.

CONCLUSION

We conclude that PTEN plays a role in inhibitory effects of TGF-β on cell proliferation whereas its absence may enhance TGF-β effects on activation of PI3-kinase pathway and cell migration.

In vitro and in vivo anti-malignant melanoma activity of Alocasia cucullata via modulation of the phosphatase and tensin homolog/phosphoinositide 3-kinase/AKT pathway

Alocasia cucullata, a Chinese herb, has been used as an anticancer treatment in southern China. Phosphatase and tensin (PTEN), is a tumor suppressor gene and the loss of PTEN expression may activate the phosphoinositide-3-kinase (PI3K)/AKT signaling pathway which play a key role in tumors formation and progression. In this study, we evaluated the anti-melanoma effect and the underlying mechanism of 50% ethanolic extract of A. cucullata (EAC) in vitro and in vivo. Using MTT, wound healing, and transwell assays, we found that EAC suppressed the proliferation, migration, and invasion of melanoma cells (B16-F10, A375 and A2058) in a dose-dependent manner. We also found that EAC suppresses B16-F10 tumor growth in a xenografted mouse model. Western blot analysis revealed that the expression level of PTEN was up-regulated, and phosphorylation of PI3K and AKT reduced in B16-F10 cells and tumor tissues after EAC treatment. No significant differences were observed in PI3K and AKT expression. Moreover, immunohistochemistry showed that the number of PTEN-positive cells in tumor tissues increased and that of p-AKT-positive cells decreased with EAC treatment, corroborating the western blot results. Our data reveal that EAC can inhibit malignant melanoma in vitro and in vivo and suggest that its anti-tumor effect is associated with modulation of the PTEN/ PI3K/AKT signaling pathway. In summary, our findings highlight a promising herbal remedy for the treatment of malignant melanoma, which warrants further study.

Investigating the role of the IGF axis as a predictor of biochemical recurrence in prostate cancer patients post-surgery

BACKGROUND

Between 20% and 35% of prostate cancer (PCa) patients who undergo treatment with curative intent (ie, surgery or radiation therapy) for localized disease will experience biochemical recurrence (BCR). Alterations in the insulin-like growth factor (IGF) axis and PTEN expression have been implicated in the development and progression of several human tumors including PCa. We examined the expression of the insulin receptor (INSR), IGF-1 receptor (IGF-1R), PTEN, and AKT in radical prostatectomy tissue of patients who developed BCR post-surgery.

METHODS

Tissue microarrays (TMA) of 130 patients post-radical prostatectomy (65 = BCR, 65 = non-BCR) were stained by immunohistochemistry for INSR, IGF-1R, PTEN, and AKT using optimized antibody protocols. INSR, IGF1-R, PTEN, and AKT expression between benign and cancerous tissue, and different Gleason grades was assessed. Kaplan-Meier survival curves were used to examine the relationship between proteins expression and BCR.

RESULTS

INSR (P < 0.001), IGF-1R (P < 0.001), and AKT (P < 0.05) expression was significantly increased and PTEN (P < 0.001) was significantly decreased in cancerous versus benign tissue. There was no significant difference in INSR, IGF-1R, or AKT expression in the cancerous tissue of non-BCR versus BCR patients (P = 0.149, P = 0.990, P = 0.399, respectively). There was a significant decrease in PTEN expression in the malignant tissue of BCR versus non-BCR patients (P = 0.011). Combinational analysis of the tissue proteins identified a combination of decreased PTEN and increased AKT or increased INSR was associated with worst outcome. We found that in each case, our hypothesized worst group was most likely to experience BCR and this was significant for combinations of PTEN+INSR and PTEN+AKT but not PTEN+IGF-1R (P = 0.023, P = 0.028, P = 0.078, respectively).

CONCLUSIONS

Low PTEN is associated with BCR and this association is strongly modified by high INSR and high AKT expression. Measurement of these proteins could help inform appropriate patient selection for postoperative adjuvant therapy and prevent BCR.

Expression levels of PTEN, HIF-1α, and VEGF as prognostic factors in ovarian cancer

OBJECTIVE

Epithelial ovarian cancer is associated with high mortality, mostly because of delayed diagnosis, necessitating the search for novel diagnostic and prognostic markers. Here we evaluated the association between expression levels of phosphatase and tensin homolog (PTEN), hypoxia-inducible factor (HIF)-1α, and vascular endothelial growth factor (VEGF), and ovarian cancer.

PATIENTS AND METHODS

Expressions of these proteins were assessed by immunohistochemistry in 21 specimens of normal ovary tissues and 76 specimens of ovarian cancer tissues. Associations with pathological characteristics and prognosis were determined using chi-square test, Kaplan-Meier method, log-rank test, and Cox regression model.

RESULTS

Expression of PTEN in ovarian cancer tissue was negatively associated with clinical stage and differentiation degree. A reverse trend was observed in association between expression of HIF-1α and VEGF, and the clinical stage of the disease. PTEN expression negatively correlated with HIF-1α and VEGF expression levels, whereas both latter positively correlated with each other. The overall survival of patients with positive PTEN expression was significantly longer than that of those with negative expression; the opposite trend was observed with HIF-1α and VEGF. The differentiation degree and expressions of HIF-1α and PTEN were dependent predictors, whereas VEGF expression, clinical stage and lymph node metastasization were independent prognostic factors in these patients.

CONCLUSIONS

PTEN, HIF-lα, and VEGF were found to be prognostic markers in ovarian cancer, with VEGF also being as an independent prognostic factor. Combined detection of their expression levels may be useful for determination of the degree of malignancy, metastasis, and prognosis of ovarian cancer.

Apoptosis induced by the methanol extract of Salvia miltiorrhiza Bunge in non-small cell lung cancer through PTEN-mediated inhibition of PI3K/Akt pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza Bunge, a well-known traditional Chinese medicinal (TCM) plant, has been used to treat cardiovascular diseases since thousands of years. Many studies reported that the active component tanshinones displayed a variety of biological activities: anti-thrombous, anti-allergic, anti-inflammatory, antioxidant and anti-tumor promoting. But the mechanism of how the active components working still need to be clarified. The anti-tumor effect of compounds of tanshinone (CTN), the methanol extract of Salvia miltiorrhiza Bunge roots, was investigated. The aim of this study was to investigate the effects of CTN on the growth inhibition, apoptosis and molecular targets of human non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

CTN-induced cytotoxicity was determined by MTT assay. The cell survival was evaluated using clonogenic survival assay. The morphology of Glc-82 cells after treatment with CTN was determined by fluorescence microscopy. Cell cycle distribution was revealed by flow cytometry. The apoptotic cells were quantified with annexin V-FITC/PI staining and flow cytometry, and observed using Hoechst 33258 staining and TUNEL assays. The expression levels of proteins were analyzed using western blot. Tumor growth was assessed by subcutaneous inoculation of cells into BALB/c nude mice.

RESULTS

CTN inhibited the proliferation of NSCLC in a dose-dependent manner and induced both early and late apoptosis. Treatment of Glc-82 cells with CTN (5-80μg/ml) significantly (p<0.05) suppressed the cell proliferation in a concentration and time-dependent manner. CTN induced significant (p<0.05) and dose-dependent apoptosis of Glc-82 cells. Cell cycle assay showed that CTN induced a G₂/M phase arrest, and significantly (p<0.05) increased expression of p53 and p21, actived caspase-3/9 and PARP1, which suggest the involvement of the mitochondria in the apoptotic signals. In addition, CTN decreased expression of the anti-apoptotic protein Bcl-2, Bcl-xl and increased expression of the pro-apoptotic protein Bax. Result also showed that CTN could increase expression levels of PTEN, and reduce the phosphorylated levels of Akt (protein kinase B) on Thr 308 and Ser 473 domain. In vivo assay showed that the antitumor effect of CTN was significantly augmented without increasing toxicity in nude mice bearing Glc-82 xenograft.

CONCLUSION

The PTEN/Akt signaling axis is defined as a critical pathway regulated by PTEN in NSCLC. CTN, the methanol extract of Salvia miltiorrhiza Bunge, are the active compounds as shown by their ability to induce apoptosis through the mitochondrial pathway of apoptosis and PTEN-mediated inhibition of PI3K/Akt pathway. CTN could inhibit tumor growth more efficiently, which supports the ethno-medicinal use of this herb as an alternative or complementary therapy for NSCLC.

Differential Expression and Clinical Significance of DNA Methyltransferase 3B (DNMT3B), Phosphatase and Tensin Homolog (PTEN) and Human MutL Homologs 1 (hMLH1) in Endometrial Carcinomas

BACKGROUND The aim of this study was to investigate the expression and the clinicopathologic significance of DNA methyltransferase 3B (DNMT3B), phosphatase and tensin homolog (PTEN) and human MutL homologs 1 (hMLH1) in endometrial carcinomas between Han and Uygur women in Xinjiang. MATERIAL AND METHODS The expression of DNMT3B, PTEN, and hMLH1 in endometrial carcinomas were assessed by immunohistochemistry, followed by an analysis of their relationship to clinical-pathological features and prognosis. RESULTS There were a 61.7% (95/154) overexpression of DNMT3B, 50.0% (77/154) loss of PTEN expression and 18.2% (28/154) loss of hMLH1 expression. The expression of DNMT3B and PTEN in endometrial carcinomas was statistically significantly different between Uygur women and Han women (p=0.001, p=0.010, respectively). DNMT3B expression was statistically significant based on the grade of endometrial carcinomas (p=0.031). PTEN loss was statistically significant between endometrioid carcinomas (ECs) and non endometrioid carcinomas (NECs) (p=0.040). DNMT3B expression was statistically significant in different myometrial invasion groups in Uygur women (p=0.010). Furthermore, the correlation of DNMT3B and PTEN expression was significant in endometrial carcinomas (p=0.021). PTEN expression was statistically significant in the overall survival (OS) rate of women with endometrial cancers (p=0.041). CONCLUSIONS Our findings suggest that PTEN and DNMT3B possess common regulation features as well as certain ethnic differences in expression between Han women and Uygur women. An interaction may exist in the pathogenesis of endometrial carcinoma. DNMT3B was expressed differently in cases of myometrial invasion and PTEN was associated with OS, which suggested that these molecular markers may be useful in the evaluation of the biological behavior of endometrial carcinomas and may be useful indicators of prognosis in women with endometrial carcinomas.

Involvement of microRNA-141-3p in 5-fluorouracil and oxaliplatin chemo-resistance in esophageal cancer cells via regulation of PTEN

microRNAs (miRNAs) act as a major regulator of acquired chemo-resistance in various types of cancer therapeutics. This study investigated the contribution of miRNAs in influencing multiple drug resistance in esophageal squamous cell carcinoma (ESCC). The sensitivity of four ESCC cell lines (EC109, EC9706, TE-1 and KYSE-150) to 5-fluorouracil (5-FU) and oxaliplatin (OX) was determined by MTT assay. A 5-FU and OX-resistant subline, EC9706R, was established by continuous exposure to stepwise increasing concentration of 5-FU and OX. Microarray technology was used to compare the differential expression of miRNAs between resistant cells and parental cells. Chemo-sensitivity assay was performed to evaluate drug response in EC9706R cells transfected with miRNA mimic or inhibitor. The direct targets of miRNA were identified by employing pathway analysis and then confirmed with luciferase assay. Sixty ESCC tissue samples and their paired adjacent normal tissues were collected to validate the expression of identified miRNA. Mouse models were further utilized to investigate the function of miRNA on acquired chemo-resistance. MicroRNA panel results indicated that a total of 12 miRNAs were differentially expressed and miR-141-3p was highly over expressed in resistant cells. Inhibition of miR-141-3p reversed acquired chemo-resistance in EC9706R cells by stimulating apoptosis. The expression of miR-141-3p was significantly increased in ESCC tissue samples compared to their matched distant normal tissues. In addition, the elevated miR-141-3p expression was found to be associated with ESCC differentiation status and TNM stage. Moreover, Phosphatase and tensin homolog (PTEN) was identified as direct target of miR-141-3p. Western blot exhibited altered protein levels of PTEN, Akt, and PI3k with miR-141-3p inhibitor. An inverse correlation between PTEN expression and miR-141-3p expression was also observed in tissue samples. EC9706R xenograft mouse model became sensitized to 5-FU and OX treatment following miR-141-3p inhibitor transfection in vivo. Our study demonstrated that miR-141-3p contributed to an acquired chemo-resistance through PTEN modulation both in vitro and in vivo.

PTEN Insufficiency Increases Breast Cancer Cell Metastasis In Vitro and In Vivo in a Xenograft Zebrafish Model

BACKGROUND/AIM

Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) insufficiency is commonly found in breast cancer patients with metastasis. We investigated the mechanisms by which PTEN affects breast cancer metastatic behavior.

MATERIALS AND METHODS

Migration and invasion assay, western blot, immunofluorescent staining and zebrafish animal model were applied.

RESULTS

We showed that PTEN insufficiency induced an increase in MCF-7 cell migration and invasion through induction of epithelial-mesenchymal transition (EMT), which was triggered by up-regulation of the EMT-inducing transcriptional factors Zeb1, Zeb2, Snail, Slug and Twist. Simultaneously, E-cadherin expression was inhibited and P-cadherin was up-regulated. Further, WNT1 inducible signaling pathway protein 1 (WISP1) and lipocalin-2 (LCN2) expressions were increased after PTEN knockdown in MCF-7 cells, which also exhibited increased filamentous actin (F-actin) synthesis and extracellular matrix metalloproteinase-2 (MMP-2) and MMP-9 expression. We further showed that PTEN knockdown in MCF-7 cells could increase cell migration in the xenograft zebrafish model.

CONCLUSION

Our findings reveal new therapeutic targets for breast cancer patients with PTEN insufficiency.

Imaging Dendrimer-Grafted Graphene Oxide Mediated Anti-miR-21 Delivery With an Activatable Luciferase Reporter

MicroRNAs (miRNAs) are a class of post-transcriptional gene regulators involved in various physiological processes including carcinogenesis, and they have emerged as potential targets for tumor theranostics. However, the employment of antisense oligonucleotides, termed anti-miRs, for antagonizing miRNA functions in vivo has largely been impeded by a lack of effective delivery carriers. Here, we describe the development of polyamidoamine (PAMAM) dendrimer and polyethylene glycol (PEG)-functionalized nanographene oxide (NGO) conjugate (NGO-PEG-dendrimer) for the efficient delivery of anti-miR-21 into non-small-cell lung cancer cells. To monitor the delivery of anti-miR-21 into cells and tumors, we also constructed an activatable luciferase reporter (Fluc-3xPS) containing three perfectly complementary sequences against miR-21 in the 3' untranslated region (UTR) of the reporter. Compared with bare dendrimer and Lipofectamine 2000 (Lipo2000), NGO-PEG-dendrimer showed considerably lower cytotoxicity and higher transfection efficiency. As demonstrated by in vitro bioluminescence imaging and Western blotting assays, NGO-PEG-dendrimer effectively delivered anti-miR-21 into the cytoplasm and resulted in the upregulation of luciferase intensity and PTEN target protein expression in a dose-dependent manner. Moreover, transfection with anti-miR-21 by NGO-PEG-dendrimer led to stronger inhibition of cell migration and invasion than did bare dendrimer or Lipo2000 transfection. The intravenous delivery of anti-miR-21 via NGO-PEG-dendrimer induced a significant increase in the bioluminescence signal within the Fluc-3xPS reporter-transplanted tumor areas. These results suggest that NGO-PEG-dendrimer could be an efficient and a potential nanocarrier for delivering RNA oligonucleotides. In addition, the strategy of combining NGO-PEG-dendrimer with an activatable luciferase reporter allows the image-guided monitoring of the delivery process, which can provide insights into the RNA-based cancer treatments.

Relevance of miR-21 in regulation of tumor suppressor gene PTEN in human cervical cancer cells

BACKGROUND

Expression of the microRNA miR-21 has been found to be altered in almost all types of cancers and it has been classified as an oncogenic microRNA or oncomir. Due to the critical functions of its target proteins in various signaling pathways, miR-21 is an attractive target for genetic and pharmacological modulation in various cancers. Cervical cancer is the second most common cause of death from cancer in women worldwide and persistent HPV infection is the main etiologic agent. This malignancy merits special attention for the development of new treatment strategies. In the present study we analyze the role of miR-21 in cervical cancer cells.

METHODS

To identify the downstream cellular target genes of upstream miR-21, we silenced endogenous miR-21 expression in a cervical intraepithelial neoplasia-derived cell lines using siRNAs. The effect of miR-21 on gene expression was assessed in cervical cancer cells transfected with the siRNA expression plasmid pSIMIR21. We identified the tumor suppressor gene PTEN as a target of miR-21 and determined the mechanism of its regulation throughout reporter construct plasmids. Using this model, we analyzed the expression of miR-21 and PTEN as well as functional effects such as autophagy and apoptosis induction.

RESULTS

In SiHa cells, there was an inverse correlation between miR-21 expression and PTEN mRNA level as well as PTEN protein expression in cervical cancer cells. Transfection with the pSIMIR21 plasmid increased luciferase reporter activity in construct plasmids containing the PTEN-3'-UTR microRNA response elements MRE21-1 and MRE21-2. The role of miR-21 in cell proliferation was also analyzed in SiHa and HeLa cells transfected with the pSIMIR21 plasmid, and tumor cells exhibited markedly reduced cell proliferation along with autophagy and apoptosis induction.

CONCLUSIONS

We conclude that miR-21 post-transcriptionally down-regulates the expression of PTEN to promote cell proliferation and cervical cancer cell survival. Therefore, it may be a potential therapeutic target in gene therapy for cervical cancer.

MicroRNA-214 Inhibits Left Ventricular Remodeling in an Acute Myocardial Infarction Rat Model by Suppressing Cellular Apoptosis via the Phosphatase and Tensin Homolog (PTEN)

The aims of the present study were to determine the role of miR-214 on left ventricular remodeling of rat heart with acute myocardial infarction (AMI) and to further investigate the underlying mechanism of miR-214-mediated myocardial protection. AMI was induced in which adenovirus-expressing miR-214 (Ad-miR-214), anti-miR-214, or Ad-GFP had been delivered into rats hearts 4 days prior, while a phosphatase and tensin homolog (PTEN) inhibitor was administered via intra-peritoneal injection 30 minutes prior to AMI. Changes in hemodynamic parameters were detected and recorded. Left ventricular (LV) dimensions and LV/BW were measured. Quantitative RT-PCR was used to determine the miR-214 expression levels of the myocytes in the infarcted, border, and non-infarcted areas of the LV. Myocardial infarct size was also measured. Flow cytometry analysis was performed to examine cellular apoptosis. Western blot analysis was performed to examine PTEN expression. The results showed that miR-214 was upregulated in both border and infarcted areas. Myocardial cell apoptosis was decreased in the Ad-miR-214 group, but was increased in the anti-miR-214 group, while there were no differences among the Ad-GFP-group, PTEN-ad-miR-214 group, or PTEN-anti-miR-214 group. Myocardial infarct size, LV dimensions, heart rate (HR), and LV end-diastolic pressure (LVEDP) were decreased while the maximal rates of rise or decline in blood pressure in the ventricular chamber (± dp/dt) and LV systolic pressure (LVSP) were increased in the Ad-miR-214 group, all of which exhibited opposite changes in the anti-miR-214 group. PTEN was downregulated in the Ad-miR-214 group and upregulated in the anti-miR-214 group. PTEN was decreased in both the border and infarcted areas compared with non-infarcted areas. The study results suggest that Ad-miR-214 improves LV remodeling and decreases the apoptosis of myocardial cells through PTEN, suggesting a possible mechanism by which Ad-miR-214 functions in protecting against AMI injury.

Analysis of expression of PTEN/PI3K pathway and programmed cell death ligand 1 (PD-L1) in malignant pleural mesothelioma (MPM)

BACKGROUND

Malignant pleural mesothelioma (MPM) frequently express elevated AKT/mTOR activity. Previous reports in gliomas, colon, breast and prostate cancer suggest that PTEN/PI3K pathway may be important for the induction of PD-L1 expression. This study explored the expression of PTEN/PI3K pathway and PD-L1 in MPM and its relationship with the patient́s prognosis

MATERIAL AND METHODS

Twenty seven consecutive MPM patients were reviewed. Formalin-fixed, paraffin-embedded tissue biopsies were used for immunohistochemical analysis of PTEN/PI3K pathway and PD-L1 RESULTS: Expression of PTEN, mTOR, pAKT, p4EBP1, peif4E, pS6 and FOXO3a was found in 88.5%, 92.3%, 78.3%, 38.5%, 100%, 52.2% and 100% of tumors and PD-L1 in 23%. We found a significant correlation between pAKT, FOXO3a and PD-L1 expression and longer overall survival (p <0.05). We did not identify significant association between the level of PD-L1 expression and alterations in PI3K pathway

CONCLUSIONS

This study shows PTEN/PI3K pathway and PD-L1 in MPM are frequently activated. Our results suggests that there is not association between PD-L1 and the involvement of the PI3K pathway in MPM.

A Viral microRNA Cluster Regulates the Expression of PTEN, p27 and of a bcl-2 Homolog

The Epstein-Barr virus (EBV) infects and transforms B-lymphocytes with high efficiency. This process requires expression of the viral latent proteins and of the 3 miR-BHRF1 microRNAs. Here we show that B-cells infected by a virus that lacks these non-coding RNAs (Δ123) grew more slowly between day 5 and day 20, relative to wild type controls. This effect could be ascribed to a reduced S phase entry combined with a moderately increased apoptosis rate. Whilst the first phenotypic trait was consistent with an enhanced PTEN expression in B-cells infected with Δ123, the second could be explained by very low BHRF1 protein and RNA levels in the same cells. Indeed, B-cells infected either by a recombinant virus that lacks the BHRF1 protein, a viral bcl-2 homolog, or by Δ123 underwent a similar degree of apoptosis, whereas knockouts of both BHRF1 microRNAs and protein proved transformation-incompetent. We find that that the miR-BHRF1-3 seed regions, and to a lesser extent those of miR-BHRF1-2 mediate these stimulatory effects. After this critical period, B-cells infected with the Δ123 mutant recovered a normal growth rate and became more resistant to provoked apoptosis. This resulted from an enhanced BHRF1 protein expression relative to cells infected with wild type viruses and correlated with decreased p27 expression, two pro-oncogenic events. The upregulation of BHRF1 can be explained by the observation that large BHRF1 mRNAs are the source of BHRF1 protein but are destroyed following BHRF1 microRNA processing, in particular of miR-BHRF1-2. The BHRF1 microRNAs are unlikely to directly target p27 but their absence may facilitate the selection of B-cells that express low levels of this protein. Thus, the BHRF1 microRNAs allowed a time-restricted expression of the BHRF1 protein to innocuously expand the virus B-cell reservoir during the first weeks post-infection without increasing long-term immune pressure.

This paper explains some of the molecular mechanisms used by the Epstein-Barr virus (EBV) BHRF1 microRNA cluster to enhance transformation of B-cells after infection. We find that B-cells exposed to a virus that lacks the BHRF1 microRNAs (Δ123) undergo more apoptosis and grow more slowly between the second and the fourth weeks after infection than cells infected by an intact virus. These effects are partly mediated by the viral protein BHRF1, a homolog of the anti-apoptotic bcl-2 protein. The viral microRNAs allow abundant expression of BHRF1 early after infection and its down-regulation when transformation has been established. The first effect is mediated by the seed regions of miR-BHRF1-2 and -3, whereas the second is dependent on RNA cleavage mediated by processing of miR-BHRF1-2. Furthermore, we found that the ability of the BHRF1 microRNAs to increase cell cycle entry is related to their ability to downregulate PTEN, a crucial negative regulator of the cell cycle. We also study the consequences of the absence of the microRNAs for the infected cells. B-cells infected with Δ123 become more resistant to apoptosis and express lower levels of p27, two events that facilitate the development of genome instability. Thus, the viral microRNAs allow rapid and innocuous expansion of infected B-cells, their long-term reservoir, thereby facilitating the life-long coexistence between the virus and its host.

Silencing of MicroRNA-21 confers the sensitivity to tamoxifen and fulvestrant by enhancing autophagic cell death through inhibition of the PI3K-AKT-mTOR pathway in breast cancer cells

Tamoxifen (TAM) and fulvestrant (FUL) represent the major adjuvant therapy to estrogen receptor-alpha positive (ER(+)) breast cancer patients. However, endocrine resistance to TAM and FUL is a great impediment for successful treatment. We hypothesized that miR-21 might alter the sensitivity of breast cancer cells to TAM or FUL by regulating cell autophagy. Using the ER(+) breast cancer cells, we knockdown miR-21.by transfection with miR-21 inhibitor, then the cells were exposed to TAM or FUL and the percentages of apoptosis and autophagy were determined. Knockdown of miR-21 significantly increased the TAM or FUL-induced apoptosis in ER(+) breast cancer cells. Further, silencing of miR-21 in MCF-7 cells enhanced cell autophagy at both basal and TAM or FUL-induced level. The increase of autophagy in miR-21-knockdown MCF-7 cells was also indicated by increase of beclin-1, LC3-II and increased GFP-LC3 dots. Importantly, knockdown of miR-21 contributed to autophagic cell death, which is responsible for part of TAM induced cell death in miR-21 inhibitor-transfected cells. Further analysis suggested that miR-21 inhibitor enhance autophagic cell death through inhibition of PI3K-AKT-mTOR pathway. MiR-21 coordinated the function of autophagy and apoptosis by targeting Phosphatase and tensin homolog (PTEN) through inhibition of PI3K-AKT-mTOR pathway. In conclusion, silencing of miR-21 increased the sensitivity of ER(+) breast cancer cells to TAM or FUL by increasing autophagic cell death. Targeting autophagy-related miRNAs is a potential strategy for overcoming endocrine resistance to TAM and FUL.

Expression of PAX2 and PTEN Correlates to Therapy Response in Endometrial Hyperplasia

AIM

To investigate if a levonorgestrel-impregnated intrauterine system (LNG-IUS) was more efficient compared to oral progestin in the clearance of the paired box 2 gene (PAX2) - and phosphatase and tensin homolog (PTEN)-null endometrial glands and assess the significance of PAX2- and PTEN-null glands as markers for therapy response in endometrial hyperplasia.

PATIENTS AND METHODS

Immunohistochemical staining using antibodies against PAX2 and PTEN was performed in 141 pre- and post-treatment endometrial biopsies comparing the effect of LNG-IUS, 10 mg medroxyprogesterone acetate (MPA) taken continuously, or 10 mg MPA taken 10 days per cycle for six months. PAX2- and PTEN-null glands were investigated by light microscopy in pre-and post-treatment biopsies.

RESULTS

Clearance of PAX2- and PTEN-null glands was significantly more efficient by LNG-IUS compared to oral MPA (p<0.000 and p=0.008, respectively) and significantly related to therapy response (p<0.000 and p=0.002, respectively).

Combined Analysis of EGFR and PTEN Status in Patients With KRAS Wild-Type Metastatic Colorectal Cancer

To determine the relationship between the expression of phosphatase and tensin homologue (PTEN) and epidermal growth factor receptor (EGFR) in metastatic colorectal cancer (mCRC) and the clinical outcome of cetuximab-containing chemotherapy. A total of 158 consecutive mCRC patients with wild-type KRAS status who received chemotherapy with or without cetuximab, and for whom tumor tissue was available, were enrolled. The EGFR and PTEN expression was determined by immunohistochemistry (IHC). A total of 158 mCRC patients with wild-type KRAS status were enrolled in the study; 51 patients received chemotherapy combined with cetuximab, 107 patients received chemotherapy alone. Patients who received chemotherapy combined with cetuximab had longer overall survival (OS) compared with patients who received chemotherapy alone. High EGFR expression was detected in 60 patients (38.0%), while normal PTEN expression was detected in 60 patients (59.5%). The PTEN status was significantly related with the histological grade. For patients who received chemotherapy combined with cetuximab the median OS of patients with high-expression of EGFR was longer than the OS of patients with low EGRF expression; 25.0 versus 19.0 months, P = 0.002. For patient with normal PTEN the median OS were longer than the median OS for patients with loss of PTEN; 24.0 versus 19.0 months, P = 0.026. The overall response rate (ORR) had a borderline association with EGFR and PTEN expression (P = 0.055 and 0.048, respectively). In a multivariate analysis, ECOG PS, EGFR status, chemotherapy ± cetuximab, and the interaction of EGFR or PTEN and chemotherapy ± cetuximab were independent prognostic factors for OS. Our findings show that chemotherapy combined with cetuximab demonstrated encouraging antitumor activity for mCRC patients with wild-type KRAS status. Especially, those who have high EGFR expression or normal PTEN expression were more likely to benefit from such a treatment strategy. Subsequent studies in clinical trial cohorts will be required to confirm the clinical utility of these markers.

Prognostic role of PPAR-γ and PTEN in the renal cell carcinoma

OBJECTIVE

To explore association of peroxisome proliferator-activated receptor gamma (PPAR-γ) and phosphatase and tensin homolog (PTEN) expressions with prognosis of renal cell carcinoma (RCC).

METHODS

Our study subjects included 87 RCC tissues, 28 paracarcinoma tissues and 21 normal renal tissues. PPAR-γ and PTEN detection was conducted using immunohistochemistry staining. The association of PPAR-γ and PTEN with the clinical parameters and prognosis of RCC was analyzed. Kaplan-Meier method and Cox's proportional hazards regression model were used for exploring the relation between variables and prognosis.

RESULTS

Among normal renal tissues, para-carcinoma tissues and renal cell carcinomas, positive PPAR-γ expression presented with a progressive tendency (P < 0.001), while positive PTEN expression a degressive tendency (P < 0.001). PPAR-γ expressions were closely related to tumor size, clinical stage and lymph node metastases (all P < 0.05). PTEN expressions were in close association with tumor size, Fuhrman grading, lymph node metastases (all P < 0.05). PPAR-γ expressions were in a negative relation with PTEN expressions (r = -0.417, P < 0.001). Negative PPAR-γ expressions confer a significantly higher overall survival rate than positive PPAR-γ expressions (P = 0.015), while negative PTEN expressions confer a significantly lower overall survival rate than positive PTEN expressions (P = 0.003). Clinical staging, Fuhrman grading, lymph node metastases, PPAR-γ and PTEN were independent prognostic factors for prognosis (all P < 0.05).

CONCLUSION

PPAR-γ and PTEN expressions are related to the clinical parameters and prognosis of RCC and may be a biomarker for prognosis of RCC.

Loss of NDRG2 enhanced activation of the NF-κB pathway by PTEN and NIK phosphorylation for ATL and other cancer development

The activation of nuclear factor kappa B (NF-κB) signaling has a central role in the development of adult T-cell leukemia/lymphoma (ATL) and many other cancers. However, the activation mechanism of the NF-κB pathways remains poorly understood. Recently, we reported that N-myc downstream-regulated gene 2 (NDRG2) is a negative regulator of the phosphoinositide 3-kinase (PI3K)/AKT pathway by promoting the active dephosphorylated form of PTEN at its C-terminus via the recruitment of PP2A. Additionally, the down-regulation of NDRG2 expression promotes the inactive phosphorylated form of PTEN, which results in constitutively active PI3K/AKT signaling in various cancer cell types. Here, we investigated the involvement of NDRG2 in modulating NF-κB signaling. The forced expression of NDRG2 in ATL cells down-regulates not only the canonical pathway by inhibiting AKT signaling but also the non-canonical pathway by inducing NF-κB-inducing kinase (NIK) dephosphorylation via the recruitment of PP2A. Therefore, NDRG2 works as a PP2A recruiter to suppress not only PI3K/AKT signaling but also NF-κB signaling, which is particularly important in host defenses or immune responses to Human T-cell leukemia virus type 1 (HTLV-1) infection. Furthermore, the loss of NDRG2 expression might play an important role in the progression of tumor development after HTLV-1 infection.

SLUG is a direct transcriptional repressor of PTEN tumor suppressor

BACKGROUND

PTEN/AKT signaling plays a key role in prostate cancer development and maintenance of prostate cancer stem cells. How other oncogenes or tumor suppressors interact with this pathway remain to be elucidated. SLUG is an zinc finger transcription factor of the Snail superfamily, and it promotes cancer metastasis and determines the mammary stem cell state.

METHODS

SLUG was overexpressed in cells by retroviral vector and knockdown of SLUG and PTEN was mediated by shRNAs-expressing lentiviruses. Expression level of SLUG and PTEN was examined by Western blot, RT-PCR, and qPCR analyses. PTEN promoter activity was measured by luciferase reporter assay. ChIP assay was used to measure the binding between SLUG and the PTEN promoter in vivo.

RESULT

We showed that overexpression of SLUG decreased expression of PTEN tumor repressor in prostate cancer cell lines 22RV1 and DU145; conversely, knockdown of SLUG expression elevated PTEN expresson at both protein and RNA level in these cells. We demonstrated that SLUG overexpression inhibits PTEN promoter activity through the proximal promoter region in prostate cancer cells. By ChIP assay, we confirmed that SLUG directly binds to the PTEN promoter region covering the E-box sites. We also showed that Slug deficiency leads to an increased expression of PTEN in mouse embryo fibroblasts and prostate tissues. Importantly, we found that overexpression of SLUG increases drug resistance of DU145 prostate cancer cell line and knockdown of SLUG by shRNA sensitizes DU145 cell line to chemotherapeutic drugs. We further demonstrated that PTEN knockdown converts drug sensitivity of DU145 cells expressing SLUG shRNA to anticancer drugs.

CONCLUSION

We provide compelling evidence showing that PTEN is a direct functional target of SLUG. Our findings offer new insight in the regulation of the PTEN/AKT pathway and provide a molecular basis for potential targeted therapies of prostate cancer Prostate 75:907-916, 2015. © 2015 Wiley Periodicals, Inc.

PTEN upregulation may explain the development of insulin resistance and type 2 diabetes with high dose statins

PURPOSE

Statins increase the incidence of new onset diabetes. Prolonged statin therapy upregulates PTEN expression. PTEN levels are also elevated in diabetic animals. Activation of protein kinase A by cAMP decreases PTEN expression. We assessed whether prolonged treatment with rosuvastatin (ROS) induces glucose intolerance by upregulating Phosphatase and Tensin Homologue on Chromosome 10 (PTEN) in mice receiving normal (ND) or Western Diet (WD) and whether concomitant treatment with cilostazol (CIL, a phosphodiesterase-3 inhibitor) attenuates the effects.

METHODS

PTEN(loxp/cre) or PTEN(+/-) mice received ND or WD without or with ROS (10 mg/kg/day). Wild-type mice received ND or WD without or with ROS, CIL (10 mg/kg/day), or ROS+CIL for 30 days. Fasting insulin and glucose tolerance test were measured as well as PTEN and P-AKT levels in skeletal muscle.

RESULTS

Serum glucose after intraperitoneal injection of glucose was higher in PTEN(loxp/cre) mice receiving WD or ROS and especially WD+ROS. Levels were lower in PTEN(+/-) mice compared to PTEN(loxp/cre) in each treatment group. CIL decreased glucose levels in mice receiving WD, ROS and their combination. Insulin levels were higher in the WD+ROS group. CIL decreased insulin in mice receiving WD+ROS. WD, ROS and especially their combination increased PTEN and decreased P-AKT levels. CIL attenuated the effect of WD, ROS and their combination.

CONCLUSIONS

Long-term ROS can induce diabetes by upregulating PTEN. CIL attenuates these changes. Partial knockdown of PTEN also ameliorates ROS-induced insulin resistance. Further studies are needed to assess the effects of increasing cAMP levels to prevent the induction of diabetes by statins.

High levels of phosphatase and tensin homolog expression predict favorable prognosis in patients with non-small cell lung cancer

OBJECTIVE

The prognostic role of phosphatase and tensin homolog (PTEN) in non-small cell lung cancer (NSCLC) has been controversial.

PATIENTS AND METHODS

In this study, levels of PTEN expression were investigated in NSCLC patients and their prognostic value in NSCLC was assessed. PTEN expression in tumor tissues from 68 NSCLC patients was analyzed using immunohistochemistry and confocal microscopy. Survival analysis was performed using the log-rank test and Cox proportional hazards regression analysis.

RESULTS

NSCLC patients classified as expressers of high levels of PTEN (n = 46) had better prognoses than those classified as expressers of low levels (mean survival 17.1 versus 12.9 months, log-rank p = 0.038). In patients with adenocarcinoma (AC), high PTEN expression (n = 9) was associated with significantly longer survival than low PTEN expression (mean survival 23.50 versus 15.54 months, log-rank p = 0.043). High levels of PTEN expression resulted in 43% reduction in risk for all NSCLC patients (HR = 0.57, 95% CI: 0.33-0.98, p = 0.041). PTEN expression and clinical stage remained significantly associated with survival after adjustment for age, sex and tumor type (HR = 0.56, 95% CI: 0.32-0.99; p = 0.048; HR = 0.54, 95% CI: 0.36-0.97; p = 0.045). No significant difference in continuous PTEN expression levels was observed among groups with different clinical or pathological characteristics (p > 0.17). When levels of PTEN expression were binarized using the optimal cutpoint, higher levels of PTEN expression were observed in patients with T1/T2 than in those with T3/T4 (80% and 58% respectively, p = 0.049) and in patients with AC than in those with squamous-cell carcinoma (SCC) (78% and 58% respectively, p = 0.08). No significant difference in binarized PTEN expression levels was found among groups with any other clinical/pathologic characteristic (p > 0.28).

CONCLUSIONS

Our results suggest that high levels of PTEN expression may be favorable prognostic marker in NSCLC patients.

Short-Term PTEN Inhibition Improves In Vitro Activation of Primordial Follicles, Preserves Follicular Viability, and Restores AMH Levels in Cryopreserved Ovarian Tissue From Cancer Patients

Introduction

In vitro activation and growth of primordial dormant follicles to produce fertilizable oocytes would provide a useful instrument for fertility preservation. The employment of Phosphatase and TENsin homolog (PTEN) inhibitors, in combination with Protein kinase B (Akt) stimulating molecules, has been previously employed to increase follicular activation through the stimulation of the PTEN-Akt pathway.

Methods

We aim to establish improved in vitro activation also for cancer patients whose ovarian tissue has already been cryopreserved. Fresh and previously cryopreserved human ovarian cortex were exposed to short-term, low-concentration and ovary-specific treatment with only a PTEN inhibitor.

Results

Our in vitro activation protocol enhances the activation mechanisms of primordial follicles in both fresh and cryopreserved samples, and enlarges growing populations without inducing apoptosis in either follicles or the surrounding stroma. Treatment augments estradiol secretion and restores the expression levels of the previously diminished Anti-Müllerian hormone by means of cryopreservation procedures. Genomic modulation of the relative expression of PTEN pathway genes was found in treated samples.

Conclusion

The in vitro activation protocol offers new alternatives for patients with cryopreserved tissue as it increases the pool of viable activated follicles available for in vitro growth procedures. The combination of ovarian tissue cryopreservation and in vitro activation of primordial follicles, the main ovarian reserve component, will be a major advancement in fertility preservation.

Methodological aspects of the molecular and histological study of prostate cancer: focus on PTEN

Prostate cancer is among the most frequent cancers in men, and despite its high rate of cure, the high number of cases results in an elevated mortality worldwide. Importantly, prostate cancer incidence is dramatically increasing in western societies in the past decades, suggesting that this type of tumor is exquisitely sensitive to lifestyle changes. Prostate cancer frequently exhibits alterations in the PTEN gene (inactivating mutations or gene deletions) or at the protein level (reduced protein expression or altered sub-cellular compartmentalization). The relevance of PTEN in this type of cancer is further supported by the fact that the sole deletion of PTEN in the murine prostate epithelium recapitulates many of the features of the human disease. In order to study the molecular alterations in prostate cancer, we need to overcome the methodological challenges that this tissue imposes. In this review we present protocols and methods, using PTEN as proof of concept, to study different molecular characteristics of prostate cancer.

Rapid in vivo validation of candidate drivers derived from the PTEN-mutant prostate metastasis genome

Human genome analyses have revealed that increasing gene copy number alteration is a driving force of incurable cancer of the prostate (CaP). Since most of the affected genes are hidden within large amplifications or deletions, there is a need for fast and faithful validation of drivers. However, classic genetic CaP engineering in mouse makes this a daunting task because generation, breeding based combination of alterations and non-invasive monitoring of disease are too time consuming and costly. To address the unmet need, we recently developed RapidCaP mice, which endogenously recreate human PTEN-mutant metastatic CaP based on Cre/Luciferase expressing viral infection, that is guided to Pten(loxP)/Trp53(loxP) prostate. Here we use a sensitized, non-metastatic Pten/Trp53-mutant RapidCaP system for functional validation of human metastasis drivers in a much accelerated time frame of only 3-4months. We used in vivo RNAi to target three candidate tumor suppressor genes FOXP1, RYBP and SHQ1, which reside in a frequent deletion on chromosome 3p and show that Shq1 cooperates with Pten and p53 to suppress metastasis. Our results thus demonstrate that the RapidCaP system forms a much needed platform for in vivo screening and validation of genes that drive endogenous lethal CaP.

Expression of p27 and PTEN and clinical characteristics in early laryngeal squamous cell carcinoma and their correlation with recurrence

Laryngeal squamous cell carcinoma is a common malignant tumor of otolaryngeal region. At present, effective treatment of laryngeal squamous cell carcinoma still depends on surgery and radiotherapy. In recent years, application of CO2 laser resection in the treatment of stage T1 glottic carcinoma can remove the tumor completely and reduce the injury of laryngeal tissues. But recurrence still happened in some postoperative patients. Here, we selected 131 patients to compare the therapeutic effects of CO2 laser resection and traditional split laryngeal surgery on the early laryngeal cancer, examined the expression of p27 and PTEN by immunohistochemistry in early laryngeal squamous cell carcinoma tissues in correlation to clinical outcome. After two years follow-up 14/85 (16.5%) of CO2 laser treatment group presented with local recurrence (recurrent group), while that of split laryngeal surgery group was 6/46 (13.0%). There was no statistical significance in recurrence rate between the two groups (P>0.05). 10 of all the 111 (9.0%) non-recurrent patients did not follow the doctor's advice to quit smoking after the operation, while 12 in the 20 (60.0%) recurrent patients did not; the difference between the two groups was statistically significant (P<0.01). The positive rates of p27 were 80.2% (105/131) and 43.5% (57/131), and that of PTEN were 83.2% (109/131) and 48.9% (64/131) in the cancer adjacent tissues (negative surgical margin tissues) and in laryngeal carcinoma tissues, respectively (P<0.001). The expression rates of p27 and PTEN in laryngeal carcinoma tissues of the recurrent group were 20.0% (4/20), 10.0% (2/20) and that in non recurrent group were 47.7% (53/111) and 55.9% (62/111), respectively, with a significant difference (P<0.001). In addition, the expression of p27 and PTEN in tumor resected marginal tissues of the recurrence group was 50.0% (10/20), 40.0% (8/20) and that in non recurrence group was 85.6% (95/111) and 91.0% (101/111), respectively; the difference was also statistically significant between both groups (P<0.001). In conclusion, there is no statistically significant difference in tumor recurrence rate between CO2 laser surgery and traditional split laryngeal surgery. Postoperative recurrence is closely related to resume smoking. The recurrence rate of p27 and/or PTEN-negative patients was higher than that of the positive ones,that should be followed up closely after treatment.

EBV-miR-BART7-3p promotes the EMT and metastasis of nasopharyngeal carcinoma cells by suppressing the tumor suppressor PTEN

The epithelial-mesenchymal transition (EMT) is crucial to cancer progression and metastasis. Although multiple cellular miRNAs have been identified to regulate the EMT and metastasis in cancers, the role of viral miRNAs in cancer progression remains largely unknown. Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV)-associated malignancy typically characterized by its early metastasis. In the present study, we have discovered the involvement of a viral miRNA, EBV-miR-BART7-3p, in the EMT and metastasis of NPC cells. Initially, we observed that EBV-miR-BART7-3p was highly expressed in NPC and positively correlated with lymph node metastasis and clinical stage of NPC. Subsequently, we demonstrated that EBV-miR-BART7-3p enhanced cell migration/invasion in vitro, cancer metastasis in vivo, and particularly the EMT characterized by loss of epithelial markers and gain of mesenchymal features in NPC cells. Furthermore, mechanistic studies disclosed that EBV-miR-BART7-3p targeted a major human tumor suppressor PTEN, modulating PI3K/Akt/GSK-3β signaling and eventually leading to the high expression and nuclear accumulation of Snail and β-catenin, which favor EMT. Knockdown of PTEN could phenocopy the effect of EBV-miR-BART7-3p, whereas re-expression of PTEN resulted in a phenotypic reversion. Moreover, these findings were supported by an observation of an EBV-positive cell model in which silencing of endogenous EBV-miR-BART7-3p partially attenuated cell migration/invasion and altered EMT protein expression pattern via reverting PI3K/Akt, Snail and β-catenin expression. Thus, this study suggests a novel mechanism by which EBV-miR-BART7-3p modulates the EMT and metastasis of NPC cells, and a clinical implication of EBV-miR-BART7-3p as a potential biomarker or therapeutic target.

Dasatinib attenuated bleomycin-induced pulmonary fibrosis in mice

Anti-fibrotic effect of dasatinib, a platelet-derived growth factor receptor (PDGFR) and Src-kinase inhibitor, was tested on pulmonary fibrosis (PF). Adult mice were divided into four groups: mice dissected 21 d after the bleomycin (BLM) instillation (0.08 mg/kg in 200 µl) (I) and their controls (II), and mice treated with dasatinib (8 mg/kg in 100 µl, gavage) for one week 14 d after BLM instillation and dissected 21 d after instillation (III) and their controls (IV). The fibrosis score and the levels of fibrotic markers were analyzed in lungs. BLM treatment-induced cell proliferation and increased the levels of collagen-1, alpha smooth muscle actin, phospho (p)-PDGFR-alpha, p-Src, p-extracellular signal-regulated kinases1/2 and p-cytoplasmic-Abelson-kinase (c-Abl) in lungs, and down-regulated PTEN expression. Dasatinib reversed these alterations in the fibrotic lung. Dasatinib limited myofibroblast activation and collagen-1 accumulation by the inhibition of PDGFR-alpha, and Src and c-Abl activations. In conclusion, dasatinib may be a novel tyrosine and Src-kinase inhibitor for PF regression in mice.

Increased hyaluronan levels in HABP1/p32/gC1qR overexpressing HepG2 cells inhibit autophagic vacuolation regulating tumor potency

Tumor growth and development is influenced by its microenvironment. A major extracellular matrix molecule involved in cancer progression is hyaluronan (HA). Hyaluronan and expression of a number of hyaladherin family proteins are dramatically increased in many cancer malignancies. One such hyaladherin, hyaluronan-binding protein 1 (HABP1/p32/gC1qR) has been considered to be a biomarker for tumor progression. Interestingly, overexpression of HABP1 in fibroblast has been shown to increase autophagy via generation of excess reactive oxygen species (ROS) and depletion of HA leading to apoptosis. Cancerous cells are often found to exhibit decreased rate of proteolysis/autophagy in comparison to their normal counterparts. To determine if HABP1 levels alter tumorigenicity of cancerous cells, HepR21, the stable transfectant overexpressing HABP1 in HepG2 cell line was derived. HepR21 has been shown to have increased proliferation rate than HepG2, intracellular HA cable formation and enhanced tumor potency without any significant alteration of intracellular ROS. In this paper we have observed that HepR21 cells containing higher endogenous HA levels, have downregulated expression of the autophagic marker, MAP-LC3, consistent with unaltered levels of endogenous ROS. In fact, HepR21 cells seem to have significant resistance to exogenous ROS stimuli and glutathione depletion. HepR21 cells were also found to be more resilient to nutrient starvation in comparison to its parent cell line. Decline in intracellular HA levels and HA cables in HepR21 cells upon treatment with HAS inhibitor (4-MU), induced a surge in ROS levels leading to increased expression of MAP-LC3 and tumor suppressors Beclin 1 and PTEN. This suggests the importance of HABP1 induced HA cable formation in enhancing tumor potency by maintaining the oxidant levels and subsequent autophagic vacuolation.

Galectin-3 and PTEN expression in pancreatic ductal adenocarcinoma, pancreatic neuroendocrine neoplasms and gastrointestinal tumors on fine-needle aspiration cytology

OBJECTIVE

Galectin-3 has been implicated in the carcinogenesis of pancreatic ductal adenocarcinoma (PDAC). Its applicability in pancreatic fine-needle aspiration (FNA) in separating malignant from benign lesions has never been addressed. In addition, a correlation between Galectin-3 and tumor suppressor phosphatase and tensin homolog (PTEN) and their potential diagnostic value has never been tested.

STUDY DESIGN

This study analyzed Galectin-3 immunohistochemical expression in FNA cell blocks of PDAC, pancreatic neuroendocrine neoplasms (PNEN), gastrointestinal stromal tumors (GIST) and non-tumor pancreatic tissue. In parallel, Galectin-3 and PTEN levels were evaluated in a tumor tissue microarray (TMA).

RESULTS

Forty-four of 46 PDAC FNA and 32 of 33 PDAC TMA demonstrated tumor-specific Galectin-3 positivity. In contrast, Galectin-3 was not detected in PNEN and GIST. Total loss of PTEN was displayed by 26 of 33 PDAC, while non-neoplastic tissues all retained PTEN expression.

CONCLUSION

Galectin-3 could be a valuable marker to help diagnose PDAC and rule out PNEN and GIST. In addition, PTEN positivity strongly argues against a diagnosis of PDAC. These data also advocate their potential diagnostic roles in the work up of challenging cytologic cases requiring ancillary test confirmation.