Association ofPTENPolymorphisms with Susceptibility to Hepatocellular Carcinoma in a Han Chinese Population

Analysis of HIF-1α expression and genetic polymorphisms in human clear cell renal cell carcinoma

Introduction: Clear cell renal cell carcinoma (ccRCC) is mostly diagnosed incidentally and has relatively high recurrence rates. Alterations in VHL/HIF and mTOR pathways are commonly present in ccRCC. The present study attempted to identify potential diagnostic markers at the biochemical and molecular level. Methods: In total, 54 subjects (36 patients with ccRCC and 18 cancer-free controls) were enrolled. ELISA was used to measure the levels of HIF-1α in the tumor and healthy kidney tissue. The association between five selected SNPs (rs779805, rs11549465, rs2057482, rs2295080 and rs701848) located in genes of pathologically relevant pathways (VHL/HIF and mTOR) and the risk of ccRCC in the Slovak cohort was studied using real-time PCR. Results: Significant differences in HIF-1α tissue levels were observed between the tumor and healthy kidney tissue (p < 0.001). In the majority (69%) of cases, the levels of HIF-1α were higher in the kidney than in the tumor. Furthermore, the concentration of HIF-1α in the tumor showed a significant positive correlation with CCL3 and IL-1β (p (R2) 0.007 (0.47); p (R2) 0.011 (0.38). No relationship between intratumoral levels of HIF-1α and clinical tumor characteristics was observed. Rs11549465, rs2057482 in the HIF1A gene did not correlate with the expression of HIF-1α either in the tumor or in the normal kidney. None of the selected SNPs has influenced the susceptibility to ccRCC. Conclusion: More research is neccesary to elucidate the role of HIF-1α in the pathogenesis of ccRCC and the association between selected SNPs and susceptibility to this cancer.

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.

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

We performed this meta-analysis to analyze the cancer risk to individuals carrying the rs701848 and rs2735343 single nucleotide polymorphisms (SNPs) in the phosphatase and tensin homolog (PTEN) gene. We searched the PubMed, EMBASE, Cochrane library and the national knowledge infrastructure of China (CNKI) databases and identified 18 eligible case-control studies with 5458 cases and 6003 controls for rs701848 as well as 5490 cases and 6209 controls for rs2735343. Our analyses demonstrated that cancer risk was associated with rs701848 in the recessive model (CC vs. CT+TT, OR=1.169, 95% CI: 1.061-1.288) and with rs2735343 in the dominant model (GC+CC vs. GG, OR=0.758, 95% CI: 0.590-0.972). Subgroup analysis showed that in Asian subjects, carrying the C allele of rs701848 or GG genotype of rs2735343 was associated with increased cancer risk. Moreover, Asian subjects carrying the TC/CC genotype or C allele of rs701848 were associated with increased risk of esophageal squamous cell cancer. This meta-analysis indicates that the PTEN rs701848 (CC) and rs2735343 (GG) polymorphisms are associated with increased cancer risk in Asian subjects.

Lack of relationship between PTEN 32-bp and TP53 16-bp Ins/Del polymorphisms and chronic hepatitis B virus infection

TP53 and phosphate and tension homolog (PTEN) are two tumor suppressor genes that regulate cell proliferation, migration, and death. P53 and PTEN deficiency has been associated with hepatic fibrosis, a prominent pathological feature associated with chronic hepatitis B (CHB). The present study is aimed to assess the association of PTEN 32-bp Ins/Del (rs34421660) and TP53 16-bp Ins/Del polymorphisms with CHB infection susceptibility. A total of 411 subjects were recruited in this case-control study of 213 patients with CHB infection and 198 healthy individuals as controls. PTEN and TP53 deletions were detected by polymerase chain reaction method. We found no significant association between PTEN 32-bp Ins/Del polymorphism and the risk for CHB using either of codominant (Ins/Del vs. Ins/Ins: P = 0.427; Del/Del vs. Ins/Ins: P = 0.235), dominant (Ins/Del + Del/Del vs. Ins/Ins P = 0.343) or recessive genetic model (Del/Del vs. Ins/Ins + Ins/Del: P = 0.516). At allelic level although the PTEN Del variant allele was more common in CHB patients compared to controls (55 vs. 51), but the difference did not reach the statistical significant range (OR 0.87, P = 0.327). Similarly, no association was observed between TP53 16-bp Ins/Del and the risk for CHB infection at both genotype and allele levels (P > 0.05). In summary, our study demonstrated that the PTEN 32-bp and TP53 16-bp Ins/Del polymorphisms did not affect the risk of CHB infection in the Iranian population.

The genetic variants in the PTEN/PI3K/AKT pathway predict susceptibility and CE(A)F chemotherapy response to breast cancer and clinical outcomes

The PI3K/PTEN/AKT pathway play a critical role in balancing cell growth and death. Epidemiologic studies suggested that mutations of the PI3K/PTEN/AKT pathway genes are associated with cancer risk, yet no data are available for PTEN rs701848, PIK3CA rs2699887, and AKT1 rs2494752 polymorphism and breast cancer(BC) risk. A case-control study was performed in 920 BC patients and 908 healthy controls using the TaqMan assay method. Overall, individuals with PTEN rs701848 TC, CC and TC/CC genotypes showed significant increased BC risk (P=0.043, P=0.002, P=0.008, respectively), and the C allele carriers had a 1.224-fold significantly increased risk of developing BC (P= 0.003). Moreover, a higher frequency of AKT rs2494752 AG genotype was observed among cases (P=0.045). Individuals harboring rs2494752 AG/AA genotype had a vital increased susceptibility to BC in the dominant model (P=0.039). More importantly, AKT1 rs2494752 GG genotype showed significantly rates of response to NCT chemotherapy (P=0.048). Furthermore, AKT1 rs2494752 AG genotype carriers showed significantly shorter DFS time, and GG genotype as the independent prognostic factor (DFS: adjusted HR=1.523, 95% CI=1.012-2.293, P=0.044; OS: adjusted HR=2.321, 95% CI=1.281-4.204, P=0.005). Moreover, MDR analysis consistently revealed that the combination of 3 selected SNPs and 7 known risk factors represented the best model to predicting BC prognosis. The luciferase assay showed that the G allele of rs2494752 significantly increased AKT1 promoter activity. These results suggest that PTEN rs701848 and AKT1 rs2494752 polymorphisms might be a candidate pharmacogenomic factor to assess the susceptibility of BC and response and prognosis prediction for interindividualized CE(A)F chemotherapy in BC patients.

Phosphatase and tensin homologue genetic polymorphisms and their interactions with viral mutations on the risk of hepatocellular carcinoma

Background:

Chronic hepatitis B virus (HBV) infection is the major cause of hepatocellular carcinoma (HCC). Some HBV mutants and dysregulation of phosphatase and tensin homolog (PTEN) may promote the development of HCC synergistically. We aimed to test the effects of PTEN genetic polymorphisms and their interactions with important HBV mutations on the development of HCC in HBV-infected subjects.

Methods:

Quantitative polymerase chain reaction was applied to genotype PTEN polymorphisms (rs1234220, rs2299939, rs1234213) in 1012 healthy controls, 302 natural clearance subjects, and 2011 chronic HBV-infected subjects including 1021 HCC patients. HBV mutations were determined by sequencing. The associations of PTEN polymorphisms and their interactions with HBV mutations with HCC risk were assessed using multivariate logistic regression analysis.

Results:

Rs1234220 C allele was significantly associated with HCC risk compared to healthy controls (adjusted odds ratio [AOR] = 1.35, 95% confidence interval [CI] = 1.07–1.69) and HCC-free HBV-infected subjects (AOR = 1.27, 95% CI = 1.01–1.57). rs1234220 C allele was significantly associated with increased frequencies of HCC-risk A1652G, C1673T, and C1730G mutations in genotype B HBV-infected subjects. Rs2299939 GT genotype was inversely associated with HCC risk in HBV-infected patients (AOR = 0.75, 95% CI = 0.62–0.92). The interaction of rs2299939 variant genotypes (GT+TT) with A3054T mutation significantly increased HCC risk (AOR = 2.41, 95% CI = 1.08–5.35); whereas its interaction with C3116T mutation significantly reduced HCC risk (AOR = 0.34, 95% CI = 0.18–0.66). These significant effects were only evident in males after stratification.

Conclusions:

PTEN polymorphisms and their interactions with HBV mutations may contribute to hepatocarcinogenesis in males. The host-virus interactions are important in identifying HBV-infected subjects who are more likely to develop HCC.

Association of specific PTEN/10q haplotypes with endometrial cancer phenotypes in African-American and European American women

OBJECTIVE

Endometrial carcinoma (EC), the most common gynecologic malignancy in the United States, affects European American (EA) women more frequently than African-American (AA) women. Yet, AA women are more likely to die from EC. Proposed etiologies for this racial disparity, such as socioeconomic status, aggressive, non-endometrioid tumor histology, and comorbid conditions, do not account for the entire disparity experienced by AA women, suggesting an unexplored genetic component. Germline mutations in PTEN cause Cowden syndrome (CS), which increases lifetime risk of endometrial cancer. In addition, somatic PTEN silencing is one of the most common initiating events in sporadic EC. Therefore, we hypothesized that specific PTEN haplotypes in the AA population may directly predispose AA women to unfavorable tumor characteristics when diagnosed with EC.

METHODS

We conducted a case-control association study of germline variations in and around the PTEN/10q region between 53 EA and 51 AA EC cases and ethnic controls.

RESULTS

Eighteen tag SNPs with minor allele frequency ≥0.1, were genotyped and used to reconstruct haplotypes. Forty-eight ancestry informative markers were genotyped control for population stratification. Two haplotypes were overrepresented in AA, and there was a trend towards tumors with higher stage and grade in patients with these haplotypes. One haplotype was overrepresented in the EA population with a trend towards more endometrioid tumors.

CONCLUSIONS

We show that specific PTEN/10q haplotypes are significantly different between EA and AA individuals (p≤0.02), and specific haplotypes may increase the risk of unfavorable tumor phenotypes in AA women diagnosed with EC.

Mannan-conjugated adenovirus enhanced gene therapy effects on murine hepatocellular carcinoma cells in vitro and in vivo

The incidence of advanced hepatocellular carcinoma (HCC) is increasing worldwide, and its prognosis is extremely poor. For some patients for whom surgical treatments are not appropriate, one can only rely on chemotherapy. In the conventional chemotherapy, side effects usually occurred in most cases due to high toxicity levels. Moreover, the development of drug resistance toward chemotherapeutic agents often prevents the successful long-term use of chemotherapy for HCC. Gene therapy represents the exciting biotechnological advance that may revolutionize the conventional fashion of cancer treatment. Overexpression of phosphatase and tensin homologue (PTEN) in cancer cells carrying deletion/mutant type of it can induce the apoptosis of cancer cells and inhibit cell proliferation. In this work, in order to make full use of the high transfectivity of adenovirus, we managed to conjugate the polysaccharide mannan (polymannose) to the surface of the adenovirus chemically under appropriate oxidizing conditions to prepare the mannan-modified adenovirus (Man-Ad5-PTEN). The cytotoxicity and anticancer activity of Man-Ad5-PTEN were assessed in vitro. Reporter gene expression of LacZ transferred by Man-Ad5-LacZ was verified on mannose receptor-deficient NIH/3T3 cells versus mannose receptor-efficient macrophages. Hepatocellular carcinoma cell lines transduced by mannan-modified adenovirus were assayed for cell cycle, apoptosis, invasion, and migration. Further, we detected the antitumor effect on intraperitoneal H22 tumor-bearing mice treated by Man-Ad5-PTEN alone or combined with chemotherapeutic agent of doxorubicin. The results demonstrated that cell growth suppression was not observed in Chang normal hepatocyte cells and the cell killing by Man-Ad5-PTEN is tumor selective. Further, the results showed that the strategy of mannan conjugation could enhance adenovirus-mediated PTEN gene therapy effects on murine hepatocellular carcinoma cells in vitro and in vivo.

The association of phosphatase and tensin homolog deleted on chromosome 10 polymorphisms and lifestyle habits with colorectal cancer risk in a Chinese population

The PI3K signaling pathway plays an important role in the development of colorectal cancer (CRC) and other neoplasm. Somatic phosphatase and tensin homolog deleted on chromosome 10 (PTEN) mutations and deletions or epigenetic silencing have been observed in multiple tumor types including CRC. To assess the association of PTEN polymorphisms and lifestyle habits with CRC risk in Chinese population, we carried out a case-control study which included 545 cases and 522 controls. In the present study, we genotyped eight single-nucleotide polymorphisms (SNPs) in PTEN and found that rs11202607 was associated with increased CRC risk (odds ratio (OR) = 1.40, 95 % confidence interval (CI) = 1.04-1.90). Stratification analysis by lifestyle habits showed a stronger association between rs11202607 and CRC risk among never tea drinkers than that among tea-drinkers (OR = 2.04, 95 % CI 1.29-3.22), and significant additive interaction between rs10490920 and tea drinking status was observed. Our study provided the evidence of an association between PTEN polymorphisms and the risk of CRC and significant additive interaction between PTEN polymorphism and tea drinking. Studies with larger sample size and further investigations into the mechanism are warranted to clarify the role of PTEN in colorectal carcinogenesis and the association between PTEN genetic variations, environment exposure, and CRC risk.

Protein tyrosine phosphatase variants in human hereditary disorders and disease susceptibilities

Reversible tyrosine phosphorylation of proteins is a key regulatory mechanism to steer normal development and physiological functioning of multicellular organisms. Phosphotyrosine dephosphorylation is exerted by members of the super-family of protein tyrosine phosphatase (PTP) enzymes and many play such essential roles that a wide variety of hereditary disorders and disease susceptibilities in man are caused by PTP alleles. More than two decades of PTP research has resulted in a collection of PTP genetic variants with corresponding consequences at the molecular, cellular and physiological level. Here we present a comprehensive overview of these PTP gene variants that have been linked to disease states in man. Although the findings have direct bearing for disease diagnostics and for research on disease etiology, more work is necessary to translate this into therapies that alleviate the burden of these hereditary disorders and disease susceptibilities in man.

Association of genetic polymorphisms in MDM2, PTEN and P53 with risk of esophageal squamous cell carcinoma

Genetic variations in MDM2, PTEN and P53 might be involved in cancer susceptibility. To assess the contribution of polymorphisms in these three genes to the risk of esophageal squamous cell carcinoma (ESCC) in a Chinese population, we genotyped MDM2 T309G, Del1518, PTEN rs701848, rs2735343 and P53 Arg72Pro polymorphisms using PCR-restriction fragment length polymorphism analysis in 226 ESCC cases and 226 cancer-free controls. Here we showed that the risk of ESCC was elevated in subjects with any of the variant genotypes of PTEN rs2735343 and P53 Arg72Pro polymorphisms, but not any genotype of MDM2 or PTEN rs701848. Moreover, multiplicative interactions were observed between PTEN rs2735343 and P53 Arg72Pro or smoking status on risk of ESCC. Our study firstly indicated that PTEN rs2735343 might be a susceptibility factor for ESCC and reaffirmed the role of P53 Arg72Pro in ESCC in this Chinese population, but did not replicate the positive association between MDM2 T309G and ESCC found previously.