Phosphatase And Tensin Homolog Gene Research Articles

Effect of stability of PTEN on hepatocellular carcinoma.

As an antioncogene gene, phosphataseandtensinhomolog (PTEN) is closely related to tumorigenesis. However, after mutation, PTEN will lose its function and no longer exert a tumor suppression effect. Through this research, we explored the impact of PTEN mutation on hepatic carcinoma (HCC) and the mechanism of PTEN for regulating HCC. First, bioinformatics was used to analyze the prognosis of PTEN in HCC. PTEN-related genes were then further analyzed by the LinkedOmics database, and GO and KEGG functional enrichment analysis were performed. Next, databases were utilized to predict the mutation and mutation frequency of PTEN. Eventually, CRISPR-Cas12a was applied to detect the R130Q mutation on PTEN in clinical samples of HCC. Finally, the fact that miR-92a-3p targets PTEN was identified by dual luciferase reporter gene assays, RT-qPCR, western blot, and rescue experiments. Bioinformatics analysis indicated the high mutation frequency of R130Q/G/L* site on the PTEN gene. Through CRISPR-Cas12a, R130Q mutation was detected on PTEN in 26 out of 40 clinical samples of HCC. On the one hand, our study revealed that CRISPR-Cas12a might play an important role in the screening and prognosis of HCC as a new clinical method to detect PTEN mutation.

Management of thyroid nodules in patient with phosphatase and tensin homolog gene (PTEN) mutation

Management of thyroid nodules in patient with phosphatase and tensin homolog gene (PTEN) mutation

Rapamycin improves social and stereotypic behavior abnormalities induced by pre-mitotic neuronal subset specific Pten deletion.

The mechanistic target of rapamycin (mTOR) pathway is a signaling system integral to neural growth and migration. In both patients and rodent models, mutations to the phosphatase and tensin homolog gene (PTEN) on chromosome 10 results in hyperactivation of the mTOR pathway, as well as seizures, intellectual disabilities and autistic behaviors. Rapamycin, an inhibitor of mTOR, can reverse the epileptic phenotype of neural subset specific Pten knockout (NS-Pten KO) mice, but its impact on behavior is not known. To determine the behavioral effects of rapamycin, male and female NS-Pten KO and wildtype (WT) mice were assigned as controls or administered 10 mg/kg of rapamycin for 2 weeks followed by behavioral testing. Rapamycin improved social behavior in both genotypes and stereotypic behaviors in NS-Pten KO mice. Rapamycin treatment resulted in a reduction of several measures of activity in the open field test in both genotypes. Rapamycin did not reverse the reduced anxiety behavior in KO mice. These data show the potential clinical use of mTOR inhibitors by showing its administration can reduce the production of autistic-like behaviors in NS-Pten KO mice.

Correlations of PTEN and ERG Immunoexpression in Prostate Carcinoma and Lesions Related to Its Natural History: Clinical Perspectives.

Purpose: The aim of our study was to observe the associations between the ETS-related gene (ERG) and the phosphatase and tensin homolog gene (PTEN) immunoexpression in prostate cancer and related lesions and highlight the clinical significance of these findings. Methods: We evaluated the immunohistochemical expression of ERG and PTEN in a series of 151 invasive prostate adenocarcinomas, including low-grade (Gleason grade pattern 3) and high-grade (Gleason grade patterns 4, 5) morphological patterns which corresponded to 45.5% and 54.4% of the cases, respectively. Additionally, we evaluated the immunoexpression of the two markers both in foci of high-grade prostatic intraepithelial neoplasia (HGPIN), as a precursor lesion of cancer, and in foci of intraductal carcinoma of the prostate (IDCP). Finally, to ensure the malignant nature of the prostate glands examined, we employed p63 and alpha-methylacyl-CoA racemase (AMACR) expression. Results: We found that PTEN loss was observed in 50.7%, and ERG positivity was detected in 41.8% of our cancerous samples. In HGPIN, PTEN loss appeared to be linked with a high-grade adjacent invasive carcinoma component which also displayed PTEN loss. As far as IDCP is concerned, ERG immunonegativity was correlated with adjacent high-grade invasive cancer, which was also ERG immunonegative. Conclusions: Our findings suggest that the clonal expansion of invasive cancer appears to be associated with distinct immunophenotypic cellular alterations of both early and late cancer-related histological lesions. Patients with PTEN loss in HGPIN in prostate biopsies should be closely monitored due to the increased likelihood of having an associated invasive high-grade carcinoma that may have not been sampled. Given the clinical significance that derives from PTEN expression in HGPIN lesions, we suggest the routine use of PTEN immunohistochemistry in prostate cancer biopsies in which HGPIN is the only finding.

Expression Profiles of Exosomal MicroRNAs Derived from Cerebrospinal Fluid in Patients with Congenital Hydrocephalus Determined by MicroRNA Sequencing.

Purpose Congenital hydrocephalus is one of the most common birth defects worldwide. Exosomal microRNAs (miRNAs) in body fluids have been implicated in many diseases. However, their involvement in cerebrospinal fluid from congenital hydrocephalus is not well understood. This study is aimed at investigating the role of dysregulated exosomal miRNAs in congenital hydrocephalus. Methods We collected cerebrospinal fluid samples from 15 congenital hydrocephalus patients and 21 control subjects. We used miRNA sequencing to generate exosomal miRNA expression profiles in three pairs of samples. We identified 31 differentially expressed exosomal miRNAs in congenital hydrocephalus and predicted their target mRNAs. Results Three microRNAs (hsa-miR-130b-3p, hsa-miR-501-5p, and hsa-miR-2113) were selected according to their fold changes and the function of their target mRNAs, and only hsa-miR-130b-3p and hsa-miR-501-5p were confirmed their expression levels in all samples. Moreover, upregulated hsa-miR-130b-3p might mediate the downregulation of the phosphatase and tensin homolog gene (PTEN), which has been associated with hydrocephalus, via binding to its 3′-untranslated region by dual-luciferase reporter assay. Conclusion This study implicates that abnormally expressed exosomal miRNAs in cerebrospinal fluid may be involved in the pathomechanism of congenital hydrocephalus.

Upregulated microRNA-126 induces apoptosis of dental pulp stem cellvia mediating PTEN-regulated Akt activation.

IntroductionHuman dental pulp stem cells (DPSCs) have potential applications in regenerative medicine. The molecular mechanisms underlying DPSCs viability and apoptosis are not completely understood. Here, we investigated the role of miR‐126 in DPSCs viability and apoptosis.Material and methodsSenescent DPSCs were compared with early passage DPSCs. real‐time PCR and microARRAY were performed to identify the differential expression of miR‐126, and western blot was performed to detect the expression of PTEN. MTT assay was utilized to reveal the proliferative rate of both senescent and early passage DPSCs. Flow cytometry was used to examine the apoptotic rate of DPSCs. Dual‐luciferase reporter assay was carried out to detect the interaction of miR‐126 and PTEN.ResultsSenescent DPSCs showed a high level of apoptosis. Further study showed that miR‐126 is upregulated in senescent DPSCs and its overexpression in early passaged DPSCs induced apoptosis. Phosphatase and tensin homolog gene (PTEN) was identified as a target of miR‐126. PTEN was downregulated in senescent DPSCs, whereas miR‐126 inhibition upregulated PTEN level, and subsequently activated Akt pathway and suppressed the apoptotic phenotype of senescent DPSCs. In addition, PTEN overexpression rescued apoptosis of DPSCs at later stage.ConclusionOur results demonstrate that the miR‐126‐PTEN‐Akt axis plays a key role in the regulation of DPSCs apoptosis and provide a candidate target to improve the functional and therapeutic potential of DPSCs.

MiR-223 Promotes Smooth Muscle Cell Proliferation and Atherosclerotic Plaque Formation by Inhibiting Phosphatase and Tensin Homolog (PTEN)/ Phosphatidylinositol 3-Kinase (PI3K) and Protein Kinase B (AKT) Signaling Pathway

Abnormal vascular smooth muscle cells (VSMCs) proliferation is the pathological basis of atherosclerosis (AS) pathogenesis. miR-223 is abnormally expressed in AS plaques and affects the proliferation of VSMCs, but the mechanism of miR-223 affecting the proliferation of VSMCs is unclear. Our study intends to investigate the mechanism of miR-223 in VSMCs proliferation and AS formation. Healthy SD rats and miR-223 knockout SD rats took high-fat diet to induce AS model. Oil red O staining was done to observe AS formation. miR-223 mimics/NC was transferred to VSMCs followed by analysis of miR-214 expression by real-time PCR, cell proliferation by CCK8 assay, phosphatase and tensin homolog gene (PTEN) level by Western blot detection. Compared with control group, after knocking out miR-223, the AS level was significantly decreased and PTEN expression was significantly elevated (P < 0 05). After transfection of miR-223 mimics into VSMCs, PTEN expression protein was significantly decreased and the number of cells was increased (P < 0 05). In addition, the luciferase signal of miR-223 mimics and pmirGLO-PTEN-3 UTR-wt co-transfection group was significantly reduced (P < 0 05). miR-223 promotes VSMCs proliferation and AS plaque formation by targeting PTEN/PI3K/Akt signaling pathway.

MiR-203 Affects Proliferation, Apoptosis and Cisplatin Resistance of Gastric Cancer Cells Through DJ-1-PTEN-PI3K/AKT Pathway

DJ-1 negatively regulates phosphatase and tensin homolog gene (PTEN). Abnormal miR-203 expression is associated with gastric cancer. Bioinformatics analysis showed a targeting relationship between miR-203 and DJ-1 3′-UTR. Our study evaluated the role of miR-203 gastric cancer cell proliferation, apoptosis, and cisplatin (DDP) resistance. The CDDP-resistant cell line SGC7901/CDDP was established and divided into miR-NC group and miR-203 mimic group followed by detecting DJ-1, PTEN and p-AKT expression, and cell apoptosis and proliferation by flow cytometry. There was a targeted relationship between miR-203 and DJ-1 mRNA. miR-203 expression in SGC7901/CDDP cells was significantly reduced compared with SGC7901 cells with elevated DJ-1 mRNA and protein level. Compared with miR-NC group, DJ-1 and p-AKT in SGC7901/CDDP cells was significantly downregulated in miR-203 mimic transfection group, while PTEN expression was significantly increased, cell apoptosis was increased, and proliferation and CDDP resistance were reduced. Decreased miR-203 and increased DJ-1 level is associated with gastric cancer drug resistance. Elevated miR-203 can downregulate DJ-1, affect the activity of PTEN-PI3K/AKT pathway, inhibit gastric cancer cell proliferation, promote cell apoptosis, and enhance the drug sensitivity to CDDP.

Study of mir-141 and its Potential Targeted mRNA PTEN Expression in Nasopharyngeal Carcinoma: From in Silico to Initial Experiment Analysis

Recently, accumulating evidences indicated that microRNA-141 (miR-141) is associated with NPC due to their abilities to affect the expression of genes that modulate tumorigenesis. Unfortunately, there is still limited publication about miR-141 expression in Vietnamese nasopharyngeal cancer patients. In this study, we adopted bioinformatics tools, such as Pictar, Target Scan, miRDB, etc. to predict its target gene. As the results, PTEN (phosphatase and tensin homolog gene), acts oncogenic role associated with biological processes lead to the nasopharyngeal carcinogenesis, was identified as the direct target of miR-141. Experimentally, we reported the evaluation of miR-141 and PTEN expression in NPC biopsy samples and non-cancerous swab samples. The present study demonstrated that miR-141 was upregulated 9.38 times, and PTEN expression was significantly lowered in NPC biopsy samples compared to non-cancerous epithelial swab samples. Our finding demonstrated that the miR-141 was upregulated and PTEN was down regulated in NPC biopsy samples. In the upcoming research, a larger clinical sample size from patients at each stage of the NPC will be performed to understand the expression pattern of the miR-141 and PTEN for further applied in early diagnosis and prognosis as well as therapeutic of NPC.

PTEN promotes apoptosis of H2O2‑injured rat nasal epithelial cells through PI3K/Akt and other pathways.

Chronic rhinosinusitis (CRS) is a form of chronic inflammation of the nasal cavity and paranasal sinus with multi‑causal pathogenesis, including oxidative stress. Several lines of evidence have demonstrated that the phosphatase and tensin homolog gene (PTEN) can inhibit the activation of phosphoinositide 3‑kinase (PI3K) to affect phosphorylation of Akt. Importantly, the PI3K/PTEN/Akt signaling pathway is associated with various types of tumors, chronic inflammatory diseases, and autoimmune disease through its regulation of cell growth, apoptosis, proliferation, and metabolism. This invitro study aimed to investigate the role of PTEN and the relationship between PTEN and the PI3K/Akt pathway in nasal epithelial cells under oxidative stress. H2O2 treatment was applied to induce a cell injury model of oxidative stress in rat nasal epithelial cells. Cells were divided into control, H2O2, H2O2+PTEN, and H2O2+siPTEN groups. Cell viability was measured using the CCK‑8 assay, and reactive oxygen species (ROS) levels and apoptosis rates were analyzed by flow cytometry (FCM). Oxidative parameters, including ROS, catalase (CAT), and malondialdehyde (MDA), were tested by enzyme‑linked immunosorbent assay (ELISA). The expression of apoptosis‑related genes and PI3K/Akt pathway was assayed by quantitative PCR (qPCR) and western blot. In H2O2‑injured cells, oxidative stress, due to increased ROS levels and apoptosis rates, was induced, and PTEN aggravated the injury. The levels of both p‑Akt and PTEN in H2O2‑injured cells were positively correlated and higher than in control cells. Unknown regulatory protein(s) may exist in the PI3K/PTEN/Akt pathway or the PTEN and PI3K/Akt pathways may be two independent signaling pathways that have cross interactions.

Longitudinal Cell-Free DNA Analysis in Patients with Small Cell Lung Cancer Reveals Dynamic Insights into Treatment Efficacy and Disease Relapse.

Patients with SCLC have a poor prognosis and limited treatment options. Because access to longitudinal tumor samples is very limited in patients with this disease, we chose to focus our studies on the characterization of plasma cell-free DNA (cfDNA) for rapid, noninvasive monitoring of disease burden. We developed a liquid biopsy assay that quantifies somatic variants in cfDNA. The assay detects single nucleotide variants, copy number alterations, and insertions or deletions in 14 genes that are frequently mutated in SCLC, including tumor protein p53 gene (TP53), retinoblastoma 1 gene (RB1), BRAF, KIT proto-oncogene receptor tyrosine kinase gene (KIT), notch 1 gene (NOTCH1), notch 2 gene (NOTCH2), notch 3 gene (NOTCH3), notch 4 gene (NOTCH4), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha gene (PIK3CA), phosphatase and tensin homolog gene (PTEN), fibroblast growth factor receptor 1 gene (FGFR1), v-myc avian myelocytomatosis viral oncogene homolog gene (MYC), v-myc avian myelocytomatosis viral oncogene lung carcinoma derived homolog gene (MYCL1), and v-myc avian myelocytomatosis viral oncogene neuroblastoma derived homolog gene (MYCN). Over the course of 26 months of peripheral blood collection, we examined 140 plasma samples from 27 patients. We detected disease-associated mutations in 85% of patient samples with mutant allele frequencies ranging from 0.1% to 87%. In our cohort, 59% of the patients had extensive-stage disease, and the most common mutations occurred in TP53 (70%) and RB1 (52%). In addition to mutations in TP53 and RB1, we detected alterations in 10 additional genes in our patient population (PTEN, NOTCH1, NOTCH2, NOTCH3, NOTCH4, MYC, MYCL1, PIK3CA, KIT, and BRAF). The observed allele frequencies and copy number alterations tracked closely with treatment responses. Notably, in several cases analysis of cfDNA provided evidence of disease relapse before conventional imaging. These results suggest that liquid biopsies are readily applicable in patients with SCLC and can potentially provide improved monitoring of disease burden, depth of response to treatment, and timely warning of disease relapse in patients with this disease.

Potential Resistance Mechanisms Revealed by Targeted Sequencing from Lung Adenocarcinoma Patients with Primary Resistance to Epidermal Growth Factor Receptor (EGFR) Tyrosine Kinase Inhibitors (TKIs)

EGFR tyrosine kinase inhibitors (TKIs) have greatly improved the prognosis of lung adenocarcinoma. However, approximately 5% to 10% of patients with lung adenocarcinoma with EGFR sensitive mutations have primary resistance to EGFR TKI treatment. The underlying mechanism is unknown. This study used next-generation sequencing to explore the mechanisms of primary resistance by analyzing 11 patients with primary resistance and 11 patients sensitive to EGFR TKIs. Next-generation targeted sequencing was performed on the Illumina X platform for 483 cancer-related genes. EGFR mutation was initially detected using the amplification refractory mutation system. Potential primary resistance mechanisms were revealed by mutations unique to the EGFR TKI resistance group. Among the 11 resistant patients, 45% (five of 11) harbored a known resistance mechanism, such as MNNG HOS Transforming gene (MET) amplification de novo T790M mutation or overlapping T790M and phosphatase and tensin homolog gene (PTEN) loss and erb-b2 receptor tyrosine kinase 2 gene (ERBB2) amplification. In six of 11 resistant cases (54%), potential novel mutations that might lead to drug resistance were identified (including transforming growth factor beta receptor 1 gene [TGFBR1] mutation and/or EGFR structural rearrangement mechanistic target of rapamycin kinase gene [MTOR] mutation, transmembrane protease, serine 2 gene [TMPRSS2] fusion gene, and v-myc avian myelocytomatosis viral oncogene homolog gene [MYC] amplification). By analyzing somatic mutation patterns, the frequency of C:G→T:A transitions in the patients with primary resistance was significantly higher than that in sensitive group and occurred more frequently in the non-CpG region (Cp(A/C/T)→T). The mechanisms of primary resistance to EGFR TKIs may be highly heterogeneous. Mutations in EGFR and its downstream pathway, as well as mutations that affect tumor cell function, are related to primary resistance. Somatic single-nucleotide mutation patterns might be associated with primary resistance to EGFR TKIs.

Abstract 4534: Taxol therapy-induced catalytic EZH2 limits therapeutic responses in PTEN null prostate cancer

Abstract Prostate cancer (PCa) is the most common cancer and a major cause of cancer related deaths in men in North America. The phosphatase and tensin homolog gene (PTEN) is frequently inactivated in PCa. Approximately 40% of primary and 70% of metastatic PCa's have genomic alterations in the PI3K-signaling, mostly through the loss of PTEN. Majority of metastatic PCa associated with PTEN loss are treated with docetaxel; an FDA approved therapy for recurrent PCa. However, in PTEN null PCa docetaxel treatment enhances senescence and does not significantly impact tumor volume. These findings were further confirmed in PCa patients with decreased levels of PTEN. In order to understand the global impact of docetaxel in PTEN null PCa we performed an unbiased RNA-seq of prostate tissues harvested from docetaxel treated prostate specific PTEN null mice. Data analysis showed strong enrichment of chromatin modifying enzymes reactome, mainly PRC2 as one of the top ranked categories. Among them EZH2, an oncogenic methyltransferase was found to be significantly upregulated. Quantitative PCR analysis confirmed statistically significant upregulation of EZH2 in docetaxel treated mice compared to vehicle control. EZH2 upregulation was independent of androgen levels as both androgen dependent and independent cells showed striking upregulation of EZH2 when treated with docetaxel. Next, we confirmed the nature of the upregulated EZH2 (catalytic or non-catalytic) by docetaxel. EZH2 methyltransferase activity assay data showed significant induction of methyltransferase activity by docetaxel in both androgen dependent and independent conditions and in PTEN null mouse tissues. Further, we measured other methyltransferase marks i.e. H3K27me1&2, H3K4me3, H3K9me3 in the presence of docetaxel and found only specific upregulation of H3K27me3, confirming upregulation of only catalytic EZH2 by docetaxel. These data suggested a need for co-targeting EZH2 during docetaxel treatment in PTEN null PCa conditions. In order to provide a proof-of-principle we performed a tumor xenograft study in nude mice implanted with PTEN null PC3 cells. Combination of DZNeP (an EZH2 inhibitor) and docetaxel significantly inhibited tumor growth compared to each agent alone. Results obtained from the xenograft studies prompted us to perform a preclinical study in prostate specific PTEN null mice. Data obtained from this study clearly showed a significant reduction in number of high grade lesions in PTEN null tumors in combination group when compared to either docetaxel or DZNeP treated mice. We also observed clearance of senescent cells and accumulation of CD8+ T cells and classical dendritic (CD8+ Clec9a+ positive) cells. Our data suggests the necessity of designing a combination therapy of targeting EZH2 during docetaxel treatment specifically, which will likely increase the efficacy of docetaxel in PTEN null PCa. Citation Format: Mohammad Imran Khan, Abid Hamid, Vaqar Mustafa Adhami, Chloe Lang, Hasan Mukhtar. Taxol therapy-induced catalytic EZH2 limits therapeutic responses in PTEN null prostate cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4534.

A microRNA-152 that targets the phosphatase and tensin homolog to inhibit low oxygen induced-apoptosis in human brain microvascular endothelial cells.

Brain damage caused by perinatal asphyxia is dangerous for neonatal infants, but the mechanism by which it occurs remains elusive. In this study, microRNA-152 (miR-152) expression was induced by low oxygen levels in rat models of hypoxia brain damage, as well as in human brain microvascular endothelial cells (HBMECs) cultured in vitro. Analysis of the sequence of miR-152 revealed that the phosphatase and tensin homolog gene (PTEN) is probably the target of miR-152 both in humans and rats. When HBMECs were transfected with miR-152 mimics, PTEN expression was inhibited at both the mRNA and protein levels. Moreover, transfection with the miR-152 mimic also inhibited apoptosis induced by hypoxia. Furthermore, expression of the pro-apoptotic gene Bax was downregulated while the anti-apoptotic gene Bcl2 was upregulated after miR-152 mimic transfection. Taken together, these results indicate that miR-152 induced by hypoxia suppresses cell apoptosis and acts as a protective factor during hypoxia by repressing PTEN.

PTEN Hamartoma Tumour Syndrome:Gastrointestinal Manifestations ofTwo Cases Diagnosed in Singapore

PTEN hamartoma tumour syndrome is associated with germline mutations in the tumour suppressor gene, PTEN (phosphatase and tensin homolog gene), leading to formation of hamartomas due to unregulated cellular proliferation. Two patients presented with complications of hamartomas, which subsequently revealed multiple polyposis of mixed histologies throughout their gastrointestinal tracts. There was no family history for PTEN hamartoma tumour syndrome and both were eventually detected to have de novo PTEN mutations. Despite fulfilling diagnostic criteria and having high probabilities of a PTEN mutation (computed using PTEN Cleveland Clinic score), there was delayed diagnosis of PTEN hamartoma tumour syndrome due to limited awareness amongst treating clinicians. Thus PTEN hamartoma tumour syndrome should still be considered as a differential in patients with similar gastrointestinal manifestations for early diagnosis and intervention.

Downregulation of microRNA-630 inhibits cell proliferation and invasion and enhances chemosensitivity in human ovarian carcinoma.

MicroRNAs (miRNAs) are a family of small non-coding RNAs (approximately 21-23 nt long) that can target genes for either degradation of mRNA or inhibition of translation. miRNAs have not been comprehensively studied in human epithelial ovarian carcinoma (EOC). MicroRNA-630 (miR-630) has been frequently observed to be aberrantly expressed in various types of tumors. The present study explored the functions of miR-630 in the proliferation, apoptosis, chemosensitivity, and invasion of EOC. Using real-time polymerase chain reaction, we detected the miR-630 expression in cancerous, benign, and normal human ovarian tissues. Then, we evaluated the role of miR-630 in cell proliferation, chemosensitivity, apoptosis, and invasion by using the Cell Counting Kit-8, Annexin-V/FITC, and transwell assay on A2780 and SKOV3 cells. Western blotting was performed for analyzing the phosphatase and tensin homolog gene (PTEN) protein expression. The miR-630 expression level was higher in ovarian cancerous tissues than in benign and normal ovarian tissues. Decreased expression of miR-630 suppressed EOC cells' proliferation, migration, and invasion as well as significantly enhanced cell apoptosis and chemosensitivity to cisplatin. Furthermore, PTEN expression was increased in A2780 cells transfected by miR-630 inhibitor in comparison with inhibitor-negative control-transfected cells. In conclusion, downregulation of miR-630 dramatically increased apoptotic cell death chemosensitivity to cisplatin and decreased the proliferation, invasion, and migration of EOC cells. MiR-630 may thus play an important role in the biological behaviors of EOC cells through negative control of the PTEN expression.

Prognosis in human glioblastoma based on expression of ligand growth hormone-releasing hormone, pituitary-type growth hormone-releasing hormone receptor, its splicing variant receptors, EGF receptor and PTEN genes.

Glioblastoma (GB) is the most frequent brain tumor. Despite recent improvement in therapeutic strategies, the prognosis of GB remains poor. Growth hormone-releasing hormone (GHRH) may act as a growth factor; antagonists of GHRH have been successfully applied for experimental treatment of different types of tumors. The expression profile of GHRH receptor, its main splice variant SV1 and GHRH have not been investigated in human GB tissue samples. We examined the expression of GHRH, full-length pituitary-type GHRH receptor (pGHRHR), its functional splice variant SV1 and non-functional SV2 by RT-PCR in 23 human GB specimens. Epidermal growth factor receptor (EGFR) and phosphatase and tensin homolog gene (PTEN) expression levels were also evaluated by quantitative RT-PCR. Correlations between clinico-pathological parameters and gene expressions were analyzed. Expression of GHRH was found to be positive in 61.9 % of samples. pGHRH receptor was not expressed in our sample set, while SV1 could be detected in 17.4 % and SV2 in 8.6 % of the GB tissues. In 65.2 and 78.3 % of samples, significant EGFR over-expression or PTEN under-representation could be detected, respectively. In 47.8 % of cases, EGFR up-regulation and PTEN down-regulation occurred together. Survival was significantly poorer in tumors lacking GHRH expression. This worse prognosis in GHRH negative group remained significant even if SV1 was also expressed. Our study shows that GHRH and SV1 genes expressed in human GB samples and their expression patterns are associated with poorer prognosis.

Recurrent Prostate Cancer Genomic Alterations Predict Response to Brachytherapy Treatment

This study aimed to evaluate the association of recurrent molecular alterations in prostate cancer, such as ERG rearrangements and phosphatase and tensin homolog gene (PTEN) deletions, with oncologic outcomes in patients with prostate cancer treated with brachytherapy. Ninety-two men underwent I-125 brachytherapy with a 145 Gy delivered dose between 2000 and 2008. Pretreatment prostate biopsies were analyzed by immunohistochemistry (IHC) and FISH for ERG rearrangement and overexpression, PTEN deletion, and expression loss. Univariable and multivariable Cox-regression analyses evaluated association of ERG and PTEN status with biochemical recurrence (BCR). Within a median follow-up of 73 months, 11% of patients experienced BCR. Of 80 samples with both IHC and FISH performed for ERG, 46 (57.8%) demonstrated rearrangement by FISH and 45 (56.3%) by IHC. Of 77 samples with both IHC and FISH for PTEN, 14 (18.2%) had PTEN deletion by FISH and 22 (28.6%) by IHC. No significant associations were found between ERG, PTEN status, and clinicopathologic features. Patients with concurrent ERG rearrangement and PTEN deletion demonstrated significantly worse relapse-free survival rates compared with those with ERG or PTEN wild type (P < 0.01). In multivariable Cox regression analysis adjusted for the effects of standard clinicopathologic features, combined ERG rearranged and PTEN deletion was independently associated with BCR (HR = 2.6; P = 0.02). Concurrent ERG rearrangement and PTEN loss was independently associated with time to BCR in patients undergoing brachytherapy. Future studies are needed to validate prostate cancer molecular subtyping for risk stratification. Identifying patients in the ERG-rearranged/PTEN-deleted molecular subclass may improve treatment personalization.

Neem leaf extract inhibits mammary carcinogenesis by altering cell proliferation, apoptosis, and angiogenesis

Plant-based medicines are useful in the treatment of cancer. Many breast cancer patients use complementary and alternative medicine in parallel with conventional treatments. Neem is historically well known in Asia and Africa as a versatile medicinal plant with a wide spectrum of biological activities. The experiments reported herein determined whether the administration of an ethanolic fraction of Neem leaf (EFNL) inhibits progression of chemical carcinogen-induced mammary tumorigenesis in rat models. Seven-week-old female Sprague Dawley rats were given a single intraperitoneal injection of N-methyl-N-nitrosourea (MNU). Upon the appearance of palpable mammary tumors, the rats were divided into vehicle-treated control groups and EFNL-treated groups. Treatment with EFNL inhibited MNU-induced mammary tumor progression. EFNL treatment was also highly effective in reducing mammary tumor burden and in suppressing mammary tumor progression even after the cessation of treatment. Further, we found that EFNL treatment effectively upregulated proapoptotic genes and proteins such as p53, B cell lymphoma-2 protein (Bcl-2)-associated X protein (Bax), Bcl-2-associated death promoter protein (Bad) caspases, phosphatase and tensin homolog gene (PTEN), and c-Jun N-terminal kinase (JNK). In contrast, EFNL treatment caused downregulation of anti-apoptotic (Bcl-2), angiogenic proteins (angiopoietin and vascular endothelial growth factor A [VEGF-A]), cell cycle regulatory proteins (cyclin D1, cyclin-dependent kinase 2 [Cdk2], and Cdk4), and pro-survival signals such as NFκB, mitogen-activated protein kinase 1 (MAPK1). The data obtained in this study demonstrate that EFNL exert a potent anticancer effect against mammary tumorigenesis by altering key signaling pathways.

The role of microRNA-26b in human adipocyte differentiation and proliferation

Recent findings indicate that microRNAs (miRNAs) are involved in the regulatory network of adipogenesis and obesity. Thus far, only a few human miRNAs are known to function as adipogenic regulators, fanning interest in studies on the functional role of miRNAs during adipogenesis in humans. In a previous study, we used a microarray to assess miRNA expression during human preadipocyte differentiation. We found that expression of the miR-26b was increased in mature adipocytes. MiR-26b is an intronic miRNA located in the intron of CTDSP1 (carboxy terminal domain, RNA polymerase II, polypeptide A, small phosphatase 1). Target prediction and Renilla luciferase analyses revealed the phosphatase and tensin homolog gene (PTEN) as a putative target gene. In this study, we found that miR-26b was gradually upregulated during adipocyte differentiation. To understand the roles of miR-26b in adipogenesis, we adopted a loss-of-function approach to silence miR-26b stably in human preadipocytes. We found that miR-26b inhibition effectively suppressed adipocyte differentiation, as evidenced by decreased lipid droplets and the ability of miR-26b to decrease mRNA levels of adipocyte-specific molecular markers and triglyceride accumulation. Furthermore, the cell growth assay revealed that miR-26b inhibition promoted proliferation. Nevertheless, it had no effect on apoptosis. Taken together, these data indicate that miR-26b may be involved in adipogenesis and could be targeted for therapeutic intervention in obesity.