Germ-line sequence variants of PTEN do not have an important role in hereditary and non-hereditary prostate cancer susceptibility

Association of genetic variations in phosphatase and tensin homolog (PTEN) gene with polycystic ovary syndrome in South Indian women: a case control study

PURPOSE

The purpose of the study was to investigate the association between gene phosphate and tensin homolog (PTEN) single nucleotide polymorphisms (SNPs) and risk of developing polycystic ovary syndrome (PCOS) in South Indian women. PTEN is one of the most important tumor suppressor genes that regulate cell proliferation, migration, and death. It is also involved in the maintenance of genome stability. PCOS is one of the most common endocrine disorders among women of reproductive age. It is a heterogeneous syndrome characterized by abnormal reproductive cycles, irregular ovulation, hormonal imbalance, hyperandrogenism, acne and hirsutism.

RESEARCH QUESTION

What is the association status of PTEN SNPs with PCOS?

METHODS

A total of 240 subjects were recruited in this case-control study comprising 110 patients with PCOS and 130 individuals without PCOS. All the subjects were of South Indian origin. The genotyping of PTEN SNPs (rs1903858 A/G, rs185262832G/A and rs10490920T/C) was carried out on DNA from subjects by polymerase chain reaction (PCR) and sequencing analysis. Haplotype frequencies for multiple loci and the standardized disequilibrium coefficient (D') for pairwise linkage disequilibrium (LD) were surveyed by Haploview Software.

RESULTS

Our results showed significant increase in the frequencies of rs1903858 A/G (P = 0.0016), rs185262832 G/A (P = 0.0122) and rs10490920 T/C (P = 0.0234) genotypes and alleles in cases compared to controls.

CONCLUSION

The PTEN (rs1903858A/G, rs185262832G/A and rs10490920T/C) gene polymorphisms may constitute an inheritable risk factor for PCOS in South Indian women.

Deficiency of PTEN and CDKN2A Tumor-Suppressor Genes in Conventional and Chondroid Chordomas: Molecular Characteristics and Clinical Relevance

Introduction

Chordoma is a malignant tumor predominantly involving the skull base and vertebral column. This study aimed to investigate the molecular characteristics of PTEN and CDKN2A in conventional and chondroid chordomas and their correlation with clinical prognosis.

Materials and Methods

A total of 42 patients were enrolled, including 26 patients with conventional chordoma and 16 patients with chondroid chordoma. Clinicopathological profiles and tissue specimens were collected. Gene sequencing and fluorescence in situ hybridization were performed to identify genetic alterations in the PTEN and CDKN2A genes. Immunohistochemical staining was used for semiquantitative evaluation of PTEN and CDKN2A expression.

Results

Gene sequencing revealed an intron SNP (c.80–96A>G) and a missense mutation (c.10G>A; p.Gly4Arg) in the PTEN gene and a missense mutation (c.442G>A; p.Ala148Thr) in the CDKN2A gene. Loss of the PTEN locus was identified in 25 (59.5%) cases, and loss of the CDKN2A locus was found in 28 (66.7%) cases. There was no significant correlation between progression-free survival (PFS)/overall survival (OS) and loss of PTEN or CDKN2A. The patients with lower PTEN expression showed significantly shorter PFS and OS than those with higher expression, while there was no significant difference in PFS or OS between patients with lower CDKN2A expression and those with higher CDKN2A expression.

Conclusion

Our findings delineated the genetic landscape and expression of PTEN and CDKN2A in chordomas. PTEN expression may serve as a prognostic and predictive biomarker for chordomas.

Genetic variants in insulin-like growth factor binding protein-3 are associated with prostate cancer susceptibility in Eastern Chinese Han men

Background

Growing evidence has indicated that insulin-like growth factor binding protein-3 (IGFBP-3) polymorphisms are associated with altered risk of prostate cancer (PCa). However, few studies have been conducted in Chinese population to validate this association.

Materials and methods

Herein, we examined the association between genetic variants in the IGFBP-3 gene and PCa risk in the Chinese Han population based on a genome-wide association study (1,417 cases and 1,008 controls), and replicated three genetic variants loci in an independent case-control study (1,755 cases and 1,523 controls) using Sequenom platform. Logistic regression analyses were performed to estimate odds ratios (ORs) and 95% confidence intervals (95% CIs).

Results

We found that in the discovery stage, rs9691259 (OR =0.691, 95% CI: 0.587–0.814, P<0.001) and rs6950179 (OR =1.420, 95% CI: 1.201–1.677, P<0.001) were significantly associated with PCa risk, whereas rs2854744 showed a marginal association with PCa risk. In the replication stage, the association between rs9691259 and rs6950179 and PCa risk was not replicated, whereas rs2854744 conferred a significant association with PCa risk (OR =1.399, 95% CI: 1.010–1.937, P=0.043). After combining the two stages, we found that rs9691259, rs6950179, and rs2854744 were all significantly associated with PCa risk.

Conclusion

This study suggests that IGFBP-3 genetic variants are significantly associated with PCa risk in the Chinese population.

FISH analysis of PTEN in endometrial carcinoma. Comparison with SNP arrays and MLPA

AIMS

To check the usefulness of a standardized protocol of PTEN FISH in 31 endometrial carcinomas (ECs) in comparison with SNP array (SNPA), multiplex ligation-dependent probe amplification (MLPA), and immunohistochemistry.

METHODS AND RESULTS

Fluorescence in-situ hybridization analysis showed two PTEN copies in 17 cases, three copies in nine cases, hemizygous deletion in two cases, and diverse cell populations with different PTEN copy number in three cases. A good correlation was seen between FISH and SNPA, particularly in cases with three copies. FISH identified two cases with entire deletion of chromosome 10, but did not identify a focal deletion of PTEN. Five cases with PTEN deletion and duplication of the second allele by SNPA were interpreted as normal by FISH. Concordance between FISH and MLPA was seen in 15 cases with two copies, and in two cases with PTEN deletion. Six cases were interpreted as amplified by MLPA, but showed polyploidy by FISH. FISH was superior to SNPA and MLPA in assessing the tumours with diverse cell populations with different PTEN copies.

CONCLUSIONS

The results show good concordance between FISH, SNPA and MLPA. SNPA was superior in tumours with deletion of one copy and duplication of the second allele. FISH was superior in assessing tumour heterogeneity.

Molecular pathways in prostate cancer

Objectives

Prostate cancer is a prevalent disease with a high impact on patients’ morbidity and mortality. Despite efforts to profile prostate cancer, the genetic alterations and biological processes that correlate with disease progression remain partially elusive. The purpose of this study is to review the recent evidence relating to the initiation and progression of prostate cancer in relation to the familial correlation of the disease, the genetic aberrations resulting in prostate cancer and the new molecular biology data regarding prostate cancer.

Materials and Methods

A Medline database search identified all the existing publications on the molecular events associated with the pathogenesis and evolution of prostate cancer. Particular emphasis was given on the specific genetic phenomena associated with prostate cancer.

Results

Like other cancers, prostate cancer is caused by an accumulation of genetic alterations in a cell that drives it to malignant growth. Specific genes and gene alterations have been suggested to play a role in its development and progression. Aneuploidy, loss of heterozygosity, gene mutations, hypermethylation and inactivation of specific tumour suppressor genes such as GSTpi, APC, MDR1, GPX3 and others have been detected in prostate cancers, but generally only at a low or moderate frequency. The androgen receptor (AR) signalling pathway may play a crucial role in the early development of prostate cancer, as well as in the development of androgen-independent disease that fails to respond to hormone deprivation therapies. Other alterations linked to the transition to hormone-independence include amplification of MYC and increased expression of ERBB2 and BCL2. Inflammatory changes may also contribute to the development of prostate cancer.

Conclusion

The identification of specific molecular markers for prostate cancer may lead to its earliest detection and better prediction of its behavior. The better understanding of the molecular events affecting prostate cancer progression may result in the introduction of new drugs to target these events thus providing a potential cure and a tool for prevention of this very common disease.