scholarly journals Phosphatase and Tensin Homolog in Non-neoplastic Digestive Disease: More Than Just Tumor Suppressor

2021 ◽  
Vol 12 ◽  
Author(s):  
Tianyu He ◽  
Xiaoyun Zhang ◽  
Jianyu Hao ◽  
Shigang Ding

The Phosphatase and tensin homolog (PTEN) gene is one of the most important tumor suppressor genes, which acts through its unique protein phosphatase and lipid phosphatase activity. PTEN protein is widely distributed and exhibits complex biological functions and regulatory modes. It is involved in the regulation of cell morphology, proliferation, differentiation, adhesion, and migration through a variety of signaling pathways. The role of PTEN in malignant tumors of the digestive system is well documented. Recent studies have indicated that PTEN may be closely related to many other benign processes in digestive organs. Emerging evidence suggests that PTEN is a potential therapeutic target in the context of several non-neoplastic diseases of the digestive tract. The recent discovery of PTEN isoforms is expected to help unravel more biological effects of PTEN in non-neoplastic digestive diseases.

2014 ◽  
Vol 37 (3) ◽  
pp. 131 ◽  
Author(s):  
Yi Sun ◽  
Bo Zhang ◽  
Jiajing Cheng ◽  
Yi Wu ◽  
Fing Xing ◽  
...  

Purpose: This study aimed to investigate the role of small non-coding RNA-222 (microRNA-222; miR-222) in the development of cervical cancer (CC). Methods: Normal and CC specimens were obtained from 18 patients. HeLa and SiHa cells were grown in Dulbecco’s modified Eagle’s medium. RT–PCR, Western blot, migration assay, flow cytometry and immunofluorescence microscopy were used for analyses. Results: When compared with normal cervical tissues, miR-222 was upregulated in human CC, and the extent of up-regulation was associated with the extent and depth of CC invasion. Expression of miR-222 was inversely related to the expression of phosphatase and tensin homolog (PTEN) and p27. The reduced the expression of PTEN and p27 by miR-222 in HeLa cells and SiHa cells was associated with increased proliferation and migration of CC cells. The expression of proteins (E-cadherin and paxillin) related to the proliferation and migration was also elevated. Conclusion: MiR-222 plays an important role in the tumorigenesis of CC, possibly by specifically down-regulating p27Kip1 and PTEN. Our findings suggest that miR-222 may serve as a new therapeutic target in CC.


2018 ◽  
Author(s):  
Taylor L. Mighell ◽  
Sara Evans-Dutson ◽  
Brian j. O’Roak

ABSTRACTPhosphatase and tensin homolog (PTEN) is a tumor suppressor frequently mutated in diverse cancers. Germline PTEN mutations are also associated with a range of clinical outcomes, including PTEN hamartoma tumor syndrome (PHTS) and autism spectrum disorder (ASD). To empower new insights into PTEN function and clinically relevant genotype-phenotype relationships, we systematically evaluated the effect of PTEN mutations on lipid phosphatase activity in vivo. Using a massively parallel approach that leverages an artificial humanized yeast model, we derived high-confidence estimates of functional impact for 7,244 single amino acid PTEN variants (86% of possible). These data uncovered novel insights into PTEN protein structure, biochemistry, and mutation tolerance. Variant functional scores can reliably discriminate likely pathogenic from benign alleles. Further, 32% of ClinVar unclassified missense variants are phosphatase deficient in our assay, supporting their reclassification. ASD associated mutations generally had less severe fitness scores relative to PHTS associated mutations (p = 7.16×10-5) and a higher fraction of hypomorphic mutations, arguing for continued genotype-phenotype studies in larger clinical datasets that can further leverage these rich functional data.


2003 ◽  
Vol 14 (4) ◽  
pp. 1-7 ◽  
Author(s):  
Jafri Malin Abdullah ◽  
Norafiza Zainuddin ◽  
Sarina Sulong ◽  
Hasnan Jaafar ◽  
Mohamad Nizam Isa

Object Several genes have been shown to carry mutations in human malignant gliomas, including the phosphatase and tensin homolog (PTEN) deleted on chromosome 10 and p16 tumor suppressor genes. Alterations of this gene located on chromosome 10 q23 and 9p21, respectively, may contribute to gliomagenesis. In this study, the authors analyzed 20 cases of malignant gliomas obtained in patients living on the east coast of Malaysia to investigate the possibilities of involvement of the PTEN and p16 genes. Methods Samples of DNA were amplified by polymerase chain reaction (PCR), analyzed by single-stranded conformation polymorphism (SSCP), and subsequently by sequencing. Two cases of glioblastoma multiforme, three cases of anaplastic astrocytoma, one case of anaplastic pleomorphic xanthoastrocytoma, and one case of anaplastic ependymoma showed SSCP band shifts in PTEN mutational analyses. The DNA sequencing analyses of these samples revealed missense and nonsense mutations, with cluster of mutations in the region 5' to the core phosphatase motif of exon 5 and the 5'-end of exon 6. No abnormal migration shifts were detected in the glioma samples analyzed for point mutations of the p16 gene. Homozygous deletions of p16 were also not detected in all samples. Conclusions These findings indicate that mutations of the PTEN genes were likely to contribute to the tumorigenesis and morphological transformations of gliomas. In addition, the alterations of the p16 gene might not play a major role in tumorigenesis of malignant gliomas in Malaysian patients.


Neurology ◽  
1998 ◽  
Vol 51 (5) ◽  
pp. 1250-1255 ◽  
Author(s):  
J. Fueyo ◽  
C. Gomez-Manzano ◽  
W. K. Alfred Yung ◽  
A. P. Kyritsis

2018 ◽  
Vol 13 (1) ◽  
pp. 155798831881690 ◽  
Author(s):  
Binshuai Wang ◽  
Mingyuan Liu ◽  
Yimeng Song ◽  
Changying Li ◽  
Shudong Zhang ◽  
...  

KLF2, a member of the Kruppel-like factor (KLF) family, is thought to be a tumor suppressor in many kinds of malignant tumors. Its functions in prostate cancer (PCa) are unknown. This study aimed to explore the role of KLF2 in the migration and invasion of PCa cells. The expression of KLF2 was measured by immunohistochemistry in PCa tissues and in paired non-tumor tissues. KLF2 and MMP2 expression in cells was measured by Western blot and RT-qPCR. Adenoviruses and siRNAs were used in cell function tests to investigate the role of KLF2 in regulating MMP2. Interactions between KLF2 and MMP2 were analyzed by a luciferase activity assay. The present study, for the first time, identified that KLF2 was downregulated both in PCa clinical tissue samples and in cancer cell lines. The overexpression of KLF2 inhibited the migration and invasion of PCa cells via the suppression of MMP2.This study demonstrates that KLF2 might act as a tumor suppressor gene in PCa and that the pharmaceutical upregulation of KLF2 may be a potential approach for treatment.


Author(s):  
Annu Makker ◽  
Madhu Mati Goel ◽  
Kumari Manu ◽  
Renu Makker

Background: Balance between endometrial cell proliferation and apoptosis is crucial for successful embryo implantation. PTEN (phosphatase and tensin homolog deleted on chromosome 10), a pro-apoptotic factor, is proposed to be one of the signaling proteins through which estrogen and progesterone act to affect cellular homeostasis. Although reports in literature have suggested role of PTEN in regulating endometrial cell proliferation and apoptosis during window of implantation, its involvement in women with unexplained infertility is not clear. In the present study, we examined expression, cellular distribution and activation status of PTEN, cell proliferation, and apoptosis in midsecretory endometrium from women with unexplained infertility as compared to fertile controls.Methods: Endometrial biopsies from infertile (n=11) and fertile women (n=22) were used for immunohistochemical evaluation of PTEN, phospho-PTEN and Ki67. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling assay was performed for detection of apoptotic cells.Results: Biopsies from infertile women as compared to fertile controls demonstrated statistically significant: i) decrease in nuclear PTEN (P < 0.001), increase in nuclear phospho-PTEN (P < 0.05), increase in nuclear and cytoplasmic phospho-PTEN/PTEN ratio (P < 0.001 and P < 0.05 respectively) in endometrial stroma, ii) increase in cytoplasmic phospho-PTEN (P < 0.001) and phospho-PTEN/PTEN ratio (P < 0.05) in glandular epithelium (GE), iii) increase in Ki67 labeling in GE (P < 0.01) and stroma (P < 0.05) and, iv) decrease in (P < 0.001) apoptosis.Conclusions: Altered PTEN expression and associated modulation in cellular homeostasis during the implantation window might contribute to mechanism underlying unexplained infertility.


2013 ◽  
Vol 03 (04) ◽  
pp. 285-293 ◽  
Author(s):  
Gan Wang ◽  
Le Wang ◽  
Vanitha Bhoopalan ◽  
Yue Xi ◽  
Deepak K. Bhalla ◽  
...  

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