Single nucleotide polymorphisms rs701848 and rs2735343 in PTEN increases cancer risks in an Asian population

Pharmacogenetic study of phosphatase and tensin homolog polymorphism (rs701848) in childhood epilepsy: relation to circulating Wnt signaling

OBJECTIVE

The present study aimed at evaluating the potential contribution of Phosphatase and Tensin Homolog (PTEN) and its gene polymorphism (PTEN rs701848 T/C) in relation to Wingless/integrase-1 (Wnt) signaling in childhood epilepsy and the impact of antiepileptic medications on their serum levels.

METHODS

This study included 100 children with epilepsy (50 pharmacoresistant and 50 pharmacoresponsive) and 50 matched controls. All subjects had their genotypes for the PTEN rs701848T/C polymorphism assessed using TaqManTM assays and real-time PCR. By using the sandwich ELISA technique, the blood concentrations of PTEN and Wnt3a were measured.

RESULTS

Serum Wnt3a levels in epileptic patients were significantly higher than in the control group, p < 0.001. Children with epilepsy who received oxcarbazepine had considerably lower serum Wnt3a levels than those who didn't, p < 0.001.With an AUC of 0.71, the cutoff value for diagnosing epilepsy as serum Wnt3a > 6.2 ng/mL has a sensitivity of 55% and a specificity of 80%. When compared to controls, epileptic children had considerably more (TT) genotype and less (TC and CC) genotypes, p < 0.05 for all. Epileptic children had significantly higher (T) allele frequency than controls, p = 0.006 with OR (95%CI) = 1.962(1.206-3.192). Pharmacoresistant epileptic children had significantly higher (TT) genotype compared to pharmacoresponsive type (p = 0.020).

CONCLUSION

We originally found a strong association between PTEN rs701848 T/C and childhood epilepsy, in particular pharmacoresistant type. Serum Wnt3a levels increased in epilepsy, but were not significantly different between different alleles of PTEN. In pharmaco-responsive children Wnt3a levels differed significantly between the different PTEN genotypes. Antiepileptics may affect Wnt3a levels.

A novel PTEN mutant caused by polymorphism in cis-regulatory elements is involved in chemosensitivity in breast cancer

Phosphatase and tensin homolog (PTEN) is one of the most important tumor suppressor genes. Although studies have shown the association between cancer and genetic polymorphisms of PTEN, the underlying molecular mechanisms of breast cancer (BC) chemosensitivity that results from PTEN polymorphism is still unclear. This study aims to investigate potential links between PTEN polymorphisms in cis-regulatory elements and BC chemosensitivity in the Chinese population. A total of 172 BC patients who received neoadjuvant chemotherapy were included in the study, including 104 chemosensitive cases and 68 chemoresistant cases. The results showed a significant association between the rs786204926 polymorphism and BC chemosensitivity. Logistic multivariate regression analysis showed that age, lymph node metastasis, and the rs786204926 genotype were risk factors for BC chemoresistance. The G allele of rs786204926 is more prone to increasing the risk of chemosensitivity in BC. Additionally, analysis using Alamut Visual showed a preference of the G allele of rs786204926 to produce a novel PTEN mutant with an insertion of 18 bases from intron 4. While the transcriptional level of PTEN remained similar in chemosensitivity and chemoresistant samples, its protein level changed significantly. Interestingly, there were significant differences in both transcription and protein levels of the novel PTEN mutant between the two groups. Furthermore, we found that the mutant was more susceptible to dephosphorylation compared with wildtype PTEN, leading to chemosensitivity through the PI3K-AKT signaling pathway. These findings indicate that novel PTEN mutants caused by polymorphisms in cis-regulatory elements may be involved in BC chemosensitivity.

Roles of PTEN inactivation and PD-1/PD-L1 activation in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the most common type of esophageal cancer in China and developing countries. The purpose of this review is to summarize the roles of inactivation of the tumor suppressor gene, phosphatase and tensin homolog (PTEN), and activation of the programmed cell death protein 1 (PD-1) upon binding to its ligand (PD-L1) in the promotion of ESCC. Studies of ESCC performed in vitro and in vivo indicated that PTEN and PD-L1 function in the regulation of cell proliferation, invasion, and migration; the epithelial-mesenchymal transition; resistance to chemotherapy and radiotherapy; and the PI3K/AKT signaling pathway. Certain genetic variants of PTEN are related to susceptibility to ESCC, and PTEN and PD-L1 also function in ESCC progression and affect the prognosis of patients with ESCC. There is also evidence that the expression of PD-L1 and PTEN are associated with the progression of certain other cancers. Future studies should further examine the relationship of PD-L1 and PTEN and their possible interactions in ESCC.

The phenomenon of multidrug resistance in glioblastomas

The most common and aggressive brain tumor in the adult population is glioblastoma (GBM). The lifespan of patients does not exceed 22 months. One of the reasons for the low effectiveness of GBM treatment is its radioresistance and chemoresistance. In the current review, we discuss the phenomenon of multidrug resistance of GBM in the context of the expression of ABC family transporter proteins and the mechanisms of proliferation, angiogenesis, and recurrence. We focused on the search of molecular targets among growth factors, receptors, signal transduction proteins, microRNAs, transcription factors, proto-oncogenes, tumor suppressor genes, and their single-nucleotide polymorphisms.

Association of polymorphisms of PTEN, AKT1, PI3K, AR, and AMACR genes in patients with prostate cancer

Polymorphic variants in the PTEN (rs2735343), PI3K (rs2699887), AKT1 (rs2494750), AR (rs17302090), and AMACR (rs3195676) genes were evaluated as possible molecular markers of susceptibility, prognosis, and progression of prostate cancer (PCa), in a case-control study. Samples consisted of 277 patients with PCa and 277 controls from Londrina, PR, Brazil. SNPs were analyzed by real-time PCR. A family history of cancer, including PCa, as well as level of schooling were risk factors for PCa. The data were obtained via logistic regression, using odds ratios with a CI 95%. The genotypes of AKT1 and AKT1+AR demonstrated an association with protection for the disease. The combination of SNPs with the histopathological tumor data between allele variants of AMACR, AKT1+AR, and AKT1+AMACR indicated an association with protection against seminal vesicle invasion. The polymorphisms AKT1+AR and PI3K+AR were associated with protection against tumor bilaterality. The genotype combinations PTEN+AMACR and PTEN+AR were associated with the risk of extracapsular extension. Of the five genes studied, two were associated with protection for PCa, four were associated with protection for some prognostic variables, and only one was associated with risk. Thus, these SNPs are candidates for markers to discriminate men with better or worse prognosis for PCa.

Establishment and characterization of novel human primary endometrial cancer cell line (ZJB-ENC1) and its genomic characteristic

The establishment of human malignant tumor cell lines can provide abundant experimental materials for understanding the biological characteristics of tumors, studying the carcinogenesis, molecular genetics and the mechanism of metastasis and evolution. In this study, a novel cell line designated ZJB-ENC1 has been established from poorly differentiated endometrioid adenocarcinoma. Cytological results showed monolayer-cultured cells were polygonal in shape and a piling-up tendency without contact inhabitation. Immunohistochemistry analysis showed that the cells were negative for ER, PR, c-erbB2, E-CAD, CD117, and OCT3/4, but strongly positive for PTEN and P16. Meanwhile, the tumorigenicity of ZJB-ENC1 was confirmed by subcutaneous transplantation of the cells into a xenograft mouse model. In addition, the results of the whole exome sequencing revealed a unique genomic characteristic of ZJB-ENC1 cells, all common and novel SNPs and InDels were identified. In conclusion, this new stable cell line may promote basic and clinical research on endometrial cancer (EC).

Pharmacogenetics of anticancer monoclonal antibodies

Pharmacogenetics is the study of therapeutic and adverse responses to drugs based on an individual’s genetic background. Monoclonal antibodies (mAbs) are a rapidly evolving field in cancer therapy, however a number of newly developed and highly effective mAbs (e.g., anti-CTLA-4 and anti-PD-1) possess pharmacogenomic profiles that remain largely undefined. Since the first chemotherapeutic mAb Rituximab was approved in 1997 by the US Food and Drug Administration for cancer treatment, a broad number of other mAbs have been successfully developed and implemented into oncological practice. Nowadays, mAbs are considered as one of the most promising new approaches for cancer treatment. The efficacy of mAb treatment can however be significantly affected by genetic background, where genes responsible for antibody presentation and metabolism, for example, can seriously affect patient outcome. This review will focus on current anticancer mAb treatments, patient genetics that shape their efficacy, and the molecular pathways that bridge the two.

Genetic alteration of Exon 5 of the PTEN gene in Indian patients with ameloblastoma

OBJECTIVE

The PI3K/Akt/mTOR pathway is one of the signaling pathways associated with the pathogenesis of ameloblastoma. The phosphatase and tensin (PTEN) homologue controls cell migration and proliferation. It monitors the level of Akt and maintains cellular integrity. The aim of the present study was to study the genetic alteration of Exon 5 of the PTEN gene in Indian patients with ameloblastoma.

STUDY DESIGN

Total DNA was extracted from formalin-fixed paraffin-embedded tissue samples from 20 cases with solid multicystic ameloblastoma (SMA) and from 10 cases with normal tooth germ. Exon 5 of the PTEN gene, was assessed for its role in the pathogenesis of ameloblastoma.

RESULTS

Five of 20 cases of SMA showed genetic alteration. Of these cases 3 (15%) showed silent mutation, 1 (5%) showed change in amino acid sequence from valine to glutamic acid, and 1 (5%) showed nonsense-mediated mRNA decay.

CONCLUSIONS

The present study showed 25% somatic mutational frequency in exonic region 5 of the PTEN gene. This may indicate its role in the pathogenesis of ameloblastoma.