The association between hypoxia-inducible factor-1 α gene C1772T polymorphism and cancer risk: a meta-analysis of 37 case-control studies

The Relation of VEGFA, VEGFR2, VEGI, and HIF1A Genetic Variants and Their Serum Protein Levels with Breast Cancer in Egyptian Patients

Breast cancer is the most common type of cancer in Egyptian females. Polymorphisms in the angiogenesis pathway have been implicated previously in cancer risk and prognosis. The aim of the current study was to determine whether certain polymorphisms in the genes of vascular endothelial growth factor A (VEGFA), vascular endothelial growth factor receptor 2 (VEGFR2), vascular endothelial growth inhibitor (VEGI), and hypoxia-inducible factor-1α (HIF1A) associated with breast cancer development. The study included 154 breast cancer patients and 132 apparently healthy age-matched females as a control group. VEGFA rs25648 genotyping was performed using (ARMS) PCR technique; while VEGFR2 rs2071559, VEGI rs6478106, and HIF-1α rs11549465 were genotyped by the PCR-RFLP method. Serum levels of VEGF, VEGFR2, VEGI, and HIF1A proteins in breast cancer patients and controls were measured by ELISA. There was a significant association between the VEGFA rs25648 C allele and breast cancer risk (OR 2.5, 95% CI 1.7-3.6, p < 0.001). VEGFA rs25648 C/C genotype was statistically significantly higher in breast cancer patients vs. control (p < 0.001). Participants with the T/T and T/C VEGFR2 rs2071559 genotypes had 5.46 and 5 higher odds, respectively, of having breast cancer than those with the C/C genotype. For the VEGI rs6478106 polymorphism, there was a higher proportion of C allele in breast cancer patients vs. control (p = 0.003). Moreover, the C/C genotype of VEGI rs6478106 was statistically significantly higher in breast cancer patients vs. control (p = 0.001). There was no significant difference in genotypes and allele frequencies of HIF1A rs11549465 polymorphism between breast cancer cases and control individuals (p > 0.05). Serum levels of VEGFA, VEGI, and HIF1A were considerably greater in women with breast cancer than in the control (p < 0.001). In conclusion, the genetic variants VEGFA rs25648, VEGFR2 rs2071559, and VEGI rs6478106 revealed a significant association with increased breast cancer risk in Egyptian patients.

Genetic variants in hypoxia-inducible factor pathway are associated with colorectal cancer risk and immune infiltration

Hypoxia-inducible factor (HIF) pathway genes influence tumorigenesis and immune status. However, the associations between genetic variants in hypoxia-related genes and colorectal cancer risk and the immune status of hypoxia-associated genes in colorectal cancer have not been systematically characterized. The associations between genetic variants and colorectal cancer risk were evaluated in Chinese, Japanese and European populations using logistic regression analysis. The relationships between target genes and tumour immune infiltration were predicted by Tumour Immune Estimation Resource (TIMER). We found that rs34533650 in EPAS1 was associated with colorectal cancer risk (OR = 1.43, 95% CI = 1.20-1.70, P(FDR)  = 8.35 × 10-4 ), and this finding was validated in two independent populations (Japanese: OR = 1.07, 95% CI = 1.01-1.15, p = 3.38 × 10-2 ; European: OR = 1.11, 95% CI = 1.03-1.19, p = 6.04 × 10-3 ). EPAS1-associated genes were enriched in immune-related pathways. In addition, we found that EPAS1 copy number variation (CNV) was associated with the degree of infiltration of immune cells and observed correlations between EPAS1 expression and immune cell infiltration levels in colorectal cancer. These results highlight that genetic variants of hypoxia-related genes play roles in colorectal cancer risk and provide new insight that EPAS1 might be a promising predictor of colorectal cancer susceptibility and immune status.

Molecular Evaluation of HIF-1α Gene Variation and Determination of Its Frequency and Association with Breast Cancer Susceptibility in Saudi Arabia

AIM

Hypoxia-inducible factor 1 (HIF-1α) is responsible in regulating oxygen homeostasis in tissues and is a central effector of the hypoxic response besides its protein overexpression has been shown to have prognostic relevance in several cancers including breast cancer. Several reports indicated that HIF-1α gene variation C1772T (Pro582Ser) is associated with increased breast susceptibility but results remained controversial. Therefore, we performed the molecular evaluation of HIF-1α gene variation and determined its frequency and association with Breast Cancer susceptibility in Saudi Arabia.

METHODS

This study was conducted on histologically confirmed Breast cancer patients and gender matched healthy women. HIF-1α C1772T (Pro582Ser) genotyping was done by Amplification refractory mutation system PCR method. The HIF-1α gene genotypes were correlated with different clinicopathological characteristics of breast cancer patients.

RESULTS

A significant difference was observed in genotype distribution of HIF-1α gene variation C1772T (Pro582Ser) between breast cancer cases and gender matched healthy controls (P=0.010). Our findings showed that the HIF- 1α variant was associated with an increased risk of Breast cancer for HIF-1α CC vs CT genotype OR = 2.20, 95% CI = (1.28 -3.77), P = 0.004) in codominant inheritance model. The significant association was reported for HIF1A for genotypes CC vs (CT+ TT) OR = 1.98, 95% CI = (1.17-3.34), P = 0.010) in dominant inheritance model tested. In case of recessive inheritance model, a non-significant association of HIF-1 alpha gene variants was reported for (CC+ CT) vs TT) OR = 1.03, 95% CI = (0. 064-16.79), P = 0.97). During the allelic comparison, a non-significant association was reported between A vs C allele among Breast cancer patients. A significant association of HIF- 1α polymorphism was reported with stage as well as distant metastasis of the disease.

CONCLUSION

A significant difference was observed in genotype distribution of HIF-1α gene variation C1772T (Pro>Ser) between breast cancer cases and gene matched healthy controls (P=0.010). HIF-1α- CT heterozygosity and CC genotype increased the susceptibility .The HIF-1α polymorphism was reported to be significantly associated with the distant metastasis of Breast cancer. Further studies with larger data set and well-designed models are required to validate our findings.

HIF1A gene polymorphisms and human diseases: Graphical review of 97 association studies

Hypoxia-inducible factors (HIFs) belong to a family of transcription factors (TF) responsive to a low O2 availability, which is often a characteristic feature of solid tumors. The alpha subunit of the HIF heterodimer is O2 -sensitive, and once stabilized in hypoxia, it functions as a master regulator of various genes involved in hypoxia pathway. Changes in the HIF1A (hypoxia inducible factor 1, alpha subunit) nucleotide sequence or expression has been shown to be associated with the development of several diseases. Because of increasing research interest in HIF1A gene a review of association studies was needed. We here reviewed published data on single nucleotide polymorphisms (SNPs) in HIF1A in various diseases; in total, 34 SNPs were tested for an association with 49 phenotypes, and the results were visualized using the Cytoscape software. Among all collected polymorphisms 16 SNPs showed significant associations with 40 different phenotypes, including six SNPs associated with 14 cancer types. Missense SNPs (rs11549465 and rs11549467) within the oxygen-dependent degradation domain were most frequently studied. The study provides a comprehensive tool for researchers working in this area and may contribute to more accurate disease diagnosis and identification of therapeutic targets.

No association of hypoxia inducible factor-1α gene polymorphisms with breast cancer in North-West Indians

BACKGROUND

Hypoxia inducible factor-1 alpha (HIF-1α) is the key regulator of cellular responses to hypoxia and plays a central role in tumour growth. Presence of Single nucleotide polymorphisms (SNPs) in the critical regulatory domains of HIF-1α may result in the overexpression of the protein and subsequent changes in the expression of the downstream target genes. The aim of study was to investigate the association of three SNPs (g.C111A, g.C1772T and g.G1790A) of HIF-1α with the risk of breast cancer in North Indian sporadic breast cancer patients.

MATERIALS AND METHODS

A total of 400 subjects, including 200 healthy controls and 200 patients with breast cancer were recruited in this study. Genotypes were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

RESULTS

The CC and CA genotype frequency of HIF-1α g.C111A polymorphism was 100 vs 99% and 0 vs 1% in breast cancer patients and healthy controls respectively. The frequencies of CC, CT and TT genotype of g.C1772T polymorphism were 76 vs 74.5%, 19 vs 21% and 5 vs 4.5% in breast cancer patients and control individuals respectively. There was no significant difference in genotype and allele frequencies of HIF-1α g.C1772T polymorphism between cases and control individuals (p>0.05). For g.G1790A genotypes, all patients and controls had only GG genotype.

CONCLUSIONS

The three HIF-1α polymorphisms (g.C111A, g.C1772T and g.G1790A) are not associated with breast cancer risk in North-West Indian patients.

Association between hypoxia-inducible factor-1α gene polymorphisms and risk of chronic hepatitis B and hepatitis B virus-related liver cirrhosis in a Chinese population: a retrospective case-control study

BACKGROUND

Our recent study demonstrated a significant association between HIF-1α polymorphisms and hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC). Since chronic hepatitis B (CHB), liver cirrhosis (LC), and HCC are progressive stages of chronic HBV infection, the aim of this study is to further determine if HIF-1α polymorphisms are associated with CHB and HBV-related LC.

METHODS

Two HIF-1α polymorphisms (rs11549465 and rs115494657) were examined in 173 healthy controls, 153 patients with CHB, and 132 patients with HBV-related LC, using the polymerase chain reaction-restriction fragment length polymorphism method. DNA sequencing was also used to validate the genotype results.

RESULTS

There were no significant differences regarding the HIF-1α rs11549465 and rs115494657 polymorphisms between the patient groups and the healthy controls, no matter the genotypes, alleles, or haplotypes. To exclude the potential influence of HBV infection in the association between HIF-1a and HBV-related LC, a comparison between the LC patients and HBV infected patients was also conducted, but a similar insignificant result was found.

CONCLUSIONS

Our data suggest that the HIF-1α gene polymorphisms might not contribute to the development of CHB and HBV-related LC in a Chinese population.

Genetic polymorphisms in hypoxia-inducible factor-1a gene and its association with HBV-related hepatocellular carcinoma in a Chinese population

Previous studies have demonstrated that hypoxia-inducible factor-1a (HIF-1a) may play a vital role in the pathogenesis of hepatocellular carcinoma (HCC). However, the relationship between HIF-1a polymorphisms and HCC has not been thoroughly investigated. The aim of this study is to determine whether HIF-1a polymorphisms are associated with HCC through a case-control study. Two polymorphisms in the HIF-1a gene (rs11549465 and rs115494657) were examined in 157 hepatitis B virus (HBV)-related HCC patients and 173 healthy controls using the polymerase chain reaction-restriction fragment length polymorphism method. DNA sequencing was used to validate genotype results. There were no significant differences in the genotype and allele frequencies of HIF-1a rs11549465 and rs115494657 polymorphisms between the HBV-related HCC patients and healthy controls. However, the data revealed that subjects with the CG haplotype have a higher susceptibility to HBV-related HCC [odds ratio (OR)=2.327, 95% confidence interval (CI)=1.578-4.721, P=0.008]. In contrast, the CA haplotype was associated with a significantly decreased risk of HBV-related HCC (OR=0.416, 95% CI=0.172-0.910, P=0.025). HIF-1a rs11549465 and rs115494657 polymorphisms appeared to be irrelevant to HBV-related HCC. However, the HIF-1a CG and CA haplotypes might be a risk factor and a protective marker, respectively, for HBV-related HCC in a Chinese population. Further investigations with a larger sample size may be required to validate the genetic effects of HIF-1a polymorphisms on HBV-related HCC.

HIF-1α genetic variants and protein expression confer the susceptibility and prognosis of gliomas

To investigate the role of HIF-1α genetic polymorphism of c.1772C>T and c.1790G>A in the incidence and prognosis of gliomas in a Chinese cohort, a total of 387 gliomas patients and 437 age- and sex-matched healthy controls were recruited. The genetic polymorphism of c.1772C>T and c.1790G>A was determined. We found that the genotype distribution at c.1772C>T showed significant difference between patients and controls. Multivariable analyses showed a significantly higher risk for gliomas in 1772TT genotype carriers (odds ratio 2.68, with CC as reference). In addition, we also found a significantly higher risk for grade III + IV gliomas was observed in 1772TT genotype carriers (odds ratio 2.21, with CC as reference). The overall survival rates in patients with 1772TT or 1772CT genotype were markedly lower compared with patients with CC (both P < 0.01). Our in vitro studies revealed that HIF-1α regulates the proliferation, migration and invasion of human glioma U251 cells. This study suggests that the c.1772C>T polymorphisms may be used as a molecular marker for gliomas occurrence, grades and clinical outcome in gliomas patients.