OBJECTIVETo explore the mechanism of PTEN gene expression silence in leukemia cells, and the effect of induced PTEN gene expression in leukemia cells.

METHODSMethylation status of PTEN in leukemic cell lines, including HL-60, Nalm-6, NB4, U937, Raji, K562 and KG-1a was assessed by methylation specific PCR (MSP). The cell lines were then treated with different concentrations of methyltransferase inhibitor 5-Aza-2'-deoxycytidine (5-Aza-CdR). After that the changes in PTEN methylation status were detected by MSP, and PTEN mRNA expression level by reverse transcription PCR (RT-PCR). Growth inhibition and apoptosis of HL-60 and Nalm-6 cells induced by 5-Aza-CdR were observed by MTT assay, and Wright and Annexin V staining, respectively.

RESULTSHypermethylation of PTEN promoter was detected in HL-60, U937, Nalm-6, Raji and KG-1a, while hypomethylation was found in NB4 and K562 by MSP. After 5-Aza-CdR treatment, the hypermethylation status of PTEN promoter in HL-60 and Nalm-6 cells was reversed and their PTEN mRNA expression levels were up regulated in dose dependent manner with the 5-Aza-CdR concentrations, and the cell apoptosis was induced.

CONCLUSIONHypermethylation in the promoter region is one of major mechanisms responsible for transcriptional suppression of PTEN. Methyltransferase inhibitor could induce the expression of PTEN gene and lead to the leukemia cells apoptosis.

Cell Line, Tumor ; DNA Methylation ; Humans ; Leukemia ; genetics ; PTEN Phosphohydrolase ; genetics ; Promoter Regions, Genetic ; genetics

MicroRNAs are negative regulators of mRNA, and latest studies show that "mRNAs can also inhibit microRNAs". With these reciprocal interactions, different mRNAs with identical "microRNA binding site" cim regulate each other by competitively binding to the same microRNA pool. This is the novel competing endogenous RNA (ceRN A)regulating mechanism. The ceRN A mechanism, which is a totally new regulating mechanism , greatly expands the regulatory network across genes. It has been proved by experimental evidence that, in HCT116 colon cancer cells,KRAS and PTEN , ZEB2 and PTEN can regulate each other by ceRNA mechanism.
Colorectal Neoplasms ; genetics ; HCT116 Cells ; Humans ; MicroRNAs ; genetics ; PTEN Phosphohydrolase ; RNA, Messenger

Child ; Codon, Nonsense ; Female ; Hamartoma Syndrome, Multiple ; diagnosis ; genetics ; Humans ; PTEN Phosphohydrolase ; genetics

Pten gene is the first antioncogene with dual phosphatase activity discovered so far, pten gene regulates the cell cycle progress, apoptosis, metastasis and invasion of the tumor cells through negatively regulating the multiple signaling transduction pathways. Multiple myeloma (MM) is a malignant tumor occurring in terminal stage of B cell differentiation. The genetic changes are considered as the important factors in MM pathogenesis, among which the deletion of antioncogene is a critical genetic change. However, little is known about the genetic change of pten in MM. This review summarizes the research advance on pten in MM including structure of pten, mechanism of pten effect and correlation of pten with MM in order to provide some references for the investigating new gene target to treat the MM.
Humans ; Multiple Myeloma ; metabolism ; therapy ; PTEN Phosphohydrolase ; genetics ; metabolism ; Signal Transduction

This study was aimed to investigate whether endothelium-specific deletion of PTEN can affect hemangioblast development in the AGM region of mouse embryos. Based on Cre/loxP system, the Tie2CrePten(loxp/loxp) and Tie2CrePten(loxp/wt) mouse embryos were obtained. The genotype was identified by PCR. After treated with type I collagenase, the AGM region was dispersed into single-cell suspension, and then was cultured in blast colony-forming cell (BL-CFC) media. The number of BL-CFC was counted 4 or 5 days later. The hematopoietic capacity of BL-CFC was detected in methylcellulose culture system and the endothelial potential was assessed by tube-like structure formation on Matrigel. The results showed that the number of BL-CFC in AGM region of Tie2CrePten(loxp/loxp) mouse embryo decreased as compared with Tie2CrePten(loxp/wt) embryo. Whereas the hematopoietic capacity of mutant BL-CFC was enhanced, the endothelial potential, as evaluated by tube-like structure formation in vitro, was significantly reduced. It is concluded that the endothelial PTEN is capable of exerting regulatory functions on both the numbers and the dual potential of hemangioblast in mouse AGM region.
Animals ; Cell Differentiation ; Cells, Cultured ; Hemangioblasts ; Hematopoietic Stem Cells ; cytology ; Mice ; PTEN Phosphohydrolase ; genetics

The purpose of our study is to investigate the prognostic value of phosphatase and tensin homolog on chromosome 10 (PTEN) expression in patients with de novo metastatic castration naïve prostate cancer (mCNPC). A total of 205 patients with mCNPC at Fudan University Shanghai Cancer Center (Shanghai, China) were retrospectively examined. Immunohistochemical staining of PTEN was performed on prostate biopsy samples of these patients. Associations among clinicopathological features, patient survival and PTEN protein expression were analyzed. PTEN loss occurred in 58 of 205 (28.3%) patients. Loss of PTEN was significantly correlated with high metastatic volume (P = 0.017). No association between PTEN expression and Gleason score was observed. Patients with PTEN loss had significantly shorter progression-free survival (PFS, P < 0.001) and overall survival (OS, P < 0.001) compared with patients with intact PTEN expression. Multivariate analysis showed that elevated alkaline phosphatase, high metastatic volume and PTEN loss were independent poor prognostic factors for PFS. The Eastern Cooperative Oncology Group performance status (ECOG PS)#8805; 2 and PTEN loss were independent poor prognostic factors for OS. The adjusted hazard ratio of PTEN loss for PFS and OS was 1.67 (95% confidence interval [CI]: 1.14-2.43, P = 0.008) and 1.95 (95% CI: 1.23-3.10, P = 0.005), respectively. PTEN loss was also significantly associated with shorter PFS (P = 0.025) and OS (P < 0.001) in patients with low-volume metastatic disease. Our data showed that PTEN loss is an independent predictor for shorter PFS and OS in patients with de novo mCNPC.
China/epidemiology* ; Humans ; Male ; PTEN Phosphohydrolase/genetics* ; Prognosis ; Prostatic Neoplasms ; Retrospective Studies

This study explored the effects of resveratrol(Res) on the expression of phosphatase and tensin homolog deleted on chromosome ten(PTEN) and the fibrosis of rat renal tubular epithelial cells in a high-glucose environment and the possible mechanism underlying the fibrosis reduction. After the pretreatment of rat renal tubular epithelial cells(NRK-52 E) cultured in a high-glucose condition with Res or PTEN inhibitor SF1670, they were divided into several groups, i.e., normal glucose(NG), normal glucose + SF1670(NS), high glucose(HG), high glucose + SF1670(HS), high glucose + Res at different concentrations(5, 10, 25 μmol·L~(-1)). The expression and distribution of E-cadherin and α-SMA in renal tubular epithelial cells were observed by immunofluorescence cytochemistry. The protein expression levels of PTEN, E-cadherin, α-SMA, p-Akt~((Thr308)) and collagen Ⅳ were determined by Western blot. Real-time PCR was employed to detect the expression of PTEN mRNA. Compared with the NG group, the HG group witnessed the reduced expression of PTEN mRNA, PTEN protein and E-cadherin protein, but saw the increased expression of α-SMA, p-Akt~((Thr308)) and collagen Ⅳ proteins. Besides, with the increase in Res concentration, the expression levels of PTEN mRNA, PTEN protein and E-cadherin protein gradually increased, while those of α-SMA, collagen Ⅳ, p-Akt~((Thr308)) proteins gradually decreased in the Res groups, showing a dose-effect dependence, compared with the HG group. No distinct difference was found between the NS group and the NG group. The expression level of E-cadherin was even lower and those of α-SMA, p-Akt~((Thr308)), and collagen Ⅳ were higher in the HS group than in the HG group, with no marked difference shown in the two groups in terms of PTEN mRNA and protein. Although the PTEN inhibitor did not affect PTEN, the expression changes of the other proteins were opposite to the results after Res treatment and the fibrosis was aggravated, which suggested that SF1670 promoted the fibrosis by inhibiting PTEN, activating Akt and increasing the synthesis of collagen Ⅳ and other extracellular matrix. The results show that Res can antagonize the high glucose-mediated fibrosis of renal tubular epithelial cells. This may be achieved via the up-regulation of PTEN and the inhibition of PI3 K/Akt signaling pathway.
Animals ; Epithelial Cells ; Fibrosis ; Glucose ; PTEN Phosphohydrolase/genetics* ; Rats ; Resveratrol/pharmacology*

Choriocarcinoma/pathology* ; Female ; Gene Deletion ; Humans ; PTEN Phosphohydrolase/genetics* ; Pregnancy ; Sequence Deletion ; Stomach Neoplasms/surgery*

OBJECTIVETo explore PTEN gene expression and its clinical significance in acute leukemia.

METHODSThe expression levels of PTEN mRNA in 5 leukemia cell lines, 87 patients with acute leukemias (AL), including 59 acute myeloid leukemia (AML), 26 acute lymphoblastic leukemia (ALL), and 2 acute hybrid leukemia, 21 AL in complete remission (AL-CR), 31 chronic myelogenous leukemia (CML) and 14 normal controls were assayed by RT-PCR.

RESULTSPTEN mRNA was detected in K562 cell line, but not in Kasumi-1, HL-60, U937, Nalm-6 cell lines. The expression ratio of PTEN mRNA between CML (61.29%) and normal control (78.57%) had no statistical difference (P > 0.05). The expression ratios of PTEN mRNA in AL (18.39%) and AL-CR (42.86%) were significantly lower than that in normal control (P < 0.01 and P < 0.05, respectively), AL also has a lower expression ratio than that of AL-CR (P < 0.05). The decreased level of PTEN mRNA had a positive correlation with poor-prognostic factors (high white blood cell count of > or = 20 x 10(9)/L and chromosome abnormality).

CONCLUSIONThere is down-regulated expression of PTEN gene in AL. PTEN gene may play a role in leukemogenesis.

Cell Line, Tumor ; Humans ; Leukemia ; genetics ; metabolism ; PTEN Phosphohydrolase ; genetics ; metabolism ; RNA, Messenger ; genetics ; Reverse Transcriptase Polymerase Chain Reaction

Objective: To investigate if microRNA (miR) -23a knockdown could attenuate angiotensin Ⅱ(AngⅡ) induced cardiac hypertrophy by activating phosphatase and tensin homolog deleted on chromosome ten(PTEN) and AMP-activated protein kinase(AMPK) pathway. Methods: Rat H9c2 cells were cultured in DMEM high glucose medium and put in 5% CO(2) incubator at 37 ℃(normal group). After 48 hours of culture, H9c2 cells were stimulated with 10 nmol/L AngⅡ to establish cell hypertrophy model (AngⅡgroup). The H9c2 cells were inoculated in a 6-well cell culture plate and cultured in an incubator at 37 ℃. When the confluence degree of cell growth was about 70%, the cells were transfected with different reagents, and 24 hours after transfection, 10 nmol/L AngⅡ was used to interfere with the cells. The H9c2 cells were divided into different groups according to the reagents, namely AngⅡ+anti-miR group(transfected with miR-23a inhibitor), Ang Ⅱ+NC group(transfected with miR-23a inhibitor negative control), Ang Ⅱ+anti-miR+si-PTEN group(cotransfected with miR-23a inhibitor and PTEN small interference RNA(siRNA)), and AngⅡ+anti-miR+si-NC group(cotransfected with miR-23a inhibitor and PTEN siRNA negative control). The surface area of single cell was measured by Image J software.The mRNA expression levels of α-actin 1 (ACTA1) and β-myosin heavy chain (β-MHC) and miR-23a were detected by quantitative real-time PCR(qRT-PCR). The expression levels of PTEN and AMPK signal pathway related proteins were detected by Western blot. In order to verify whether miR-23a targets PTEN gene, double luciferase reporter gene experiment was performed. The luciferase reporter gene vector recombinant plasmids of wild type pGL-WT-PTEN and mutant pGL-MUT-PTEN were constructed and prepared after normal sequencing. H9c2 cells was inoculated into 24-well cell culture plate and cultured overnight in 37 ℃ incubator. The cells were co-transfected with miR-23a mimic or miR-23a mimic negative control and wild type or mutant reporter gene recombinant plasmid. Forty-eight hours after transfection, firefly luciferase activity and sea kidney luciferase activity were measured, and the ratio of them was recorded as relative luciferase activity. Results: Compared with the normal group, the cell surface area, the mRNA expression levels of ACTA1, β-MHC and miR-23a were significantly higher, while the protein expression levels of PTEN and p-AMPK were significantly lower in the Ang Ⅱ group(all P<0.05). The results of double luciferase reporter gene assay showed that the relative luciferase activity of cells co-transfected with miR-23a mimic and wild-type reporter gene recombinant plasmid was lower than that of miR-23a mimic negative control (P<0.05), and PTEN served as the target gene of miR-23a. In AngⅡ+anti-miR group the mRNA expression levels of miR-23a, ACTA1 and β-MHC were lower, and the cell surface area was smaller, while the protein expression levels of PTEN and p-AMPK were higher than that in AngⅡ group and AngⅡ+NC group(all P<0.05). Compared with AngⅡ+anti-miR group, the cell surface area was bigger, the expression of ACTA1 and β-MHC mRNA was up-regulated, and the protein expression levels of PTEN and p-AMPK were down-regulated in Ang Ⅱ+anti-miR+si-PTEN group(all P<0.05). Conclusion: Inhibition of miR-23a can attenuate Ang Ⅱ-induced hypertrophy in H9c2 cells through targeting PTEN and activating AMPK signaling pathway.
AMP-Activated Protein Kinases ; Angiotensin II ; Animals ; Cardiomegaly ; Cell Line ; Cell Proliferation ; MicroRNAs/genetics* ; PTEN Phosphohydrolase ; Rats ; Signal Transduction