HIF1A, EPAS1, and VEGFA: angiogenesis and hypoxia-related gene expression in endometrium and endometrial epithelial tumors

Abstract

Endometrial cancer (EC) is the second most frequent gynecological malignancy and the sixth most common women's cancer worldwide. EC incidence rate is increasing rapidly. Apart from the classical, we should consider angiogenesis and hypoxia-related genes as a reason for EC manifestation and progression. We compared the patterns of HIF1A, EPAS1, and VEGFA (genes of interest - GOIs) mRNA expression in 92 cases. HIF1A and VEGFA levels were higher in EC patients than in controls. VEGFA differed significantly between controls and both tumor grades G2 and G3, and we observed a positive correlation for HIF1A and VEGFA with EC grading. VEGFA levels were significantly higher in post-menopausal compared to pre-menopausal patients. All GOIs demonstrated strong correlations in pre-menopausal cases and weak correlations in post-menopausal cases. A positive correlation was observed in pre-menopausal controls for all GOIs and in post-menopausal patients for only EPAS1 and VEGFA. HIF1A and EPAS1 positively correlated with VEGFA in post-menopausal EC cases. Multiple linear regression analyses revealed that menopause, body mass index (BMI), and HIF1A expression are significant stimulating factors for EC occurrence. HIF1A levels were higher in EC patients after BMI and comorbidity number adjustment. The gene-to-gene relation could be seen as either a diagnostic or a therapeutic target in EC. Physicians should inform patients about modifiable risk factors such as BMI. Second, more attention should be paid to diagnosing patients with comorbidities in older age and after menopause. These factors should be considered in designing angiogenesis and hypoxia-related gene-targeting therapies.

Keywords: Endometrial cancer (EC); Hypoxia-inducible factor 1A gene (HIF1A); Hypoxia-inducible factor 2A/endothelial PAS domain protein 1 gene (HIF2A/EPAS1); Hypoxia-inducible factors (HIFs); Vascular endothelial growth factor A gene (VEGFA).

Fig. 1

Patients’ characteristics (case number is shown in brackets). N/A, data not available ¹ — hypertension, diabetes, thyroid lesions, varicose veins, stroke, heart diseases, cataract, glaucoma, COPD, psoriasis, cities, ulcerative colitis, asthma

Fig. 2

Violin-plot of age, BMI, and comorbidities number in controls and patients; *p < 0.05; **p < 0.01; and ***p < 0.001

Fig. 3

Violin-plot of HIF1A, EPAS1, and VEGFA normalized expression level in controls and patients; *p < 0.05 and ***p < 0.001

Fig. 4

Odds ratio (OR) profiles with 95% confidence intervals (95% CI) for analyzed genes’ expression profiles in controls and cancer-affected specimens. The horizontal line represents OR = 1

Fig. 5

Dot-plot of normalized min–max expression level of HIF1A, EPAS1, and VEGFA normalized expression level in all cases (upper panel) and in controls and patients (lower panel); *p < 0.05, **p < 0.01, and ***p < 0.001; R, Spearman’s rank correlation coefficient

Fig. 6

Violin-plot and significant Jonckheere-Tempestra trend (solid line) of HIF1A, EPAS1, and VEGFA normalized expression level controls and patients samples ordered by grading; **p < 0.01, ***p < 0.001

Fig. 7

Dot-plot of normalized min–max expression level of HIF1A, EPAS1, and VEGFA normalized expression level with the increasing malignancy, from unchanged, control tissue to poorly differentiated—high grade G3 tumors; N/A, not available, N/S, not significant, *p < 0.05, ***p < 0.001; R, Spearman’s rank correlation coefficient

Fig. 8

The pre-menopausal and post-menopausal ratio of cases in the control and cancer patients group

Fig. 9

Violin-plot of HIF1A, EPAS1, and VEGFA normalized expression level in pre-menopausal and post-menopausal women; *p < 0.05

Fig. 10

Dot-plot of normalized min–max expression level of HIF1A, EPAS1, and VEGFA normalized expression level in pre-menopausal and post-menopausal cases; *p < 0.05, ***p < 0.001; R, Spearman’s rank correlation coefficient

Fig. 11

Violin-plot of HIF1A, EPAS1, and VEGFA normalized expression level in patients and control samples divided accordingly to menopausal status; *p < 0.05, **p<0.01

Fig. 12

Dot-plot of normalized min–max expression level of HIF1A, EPAS1, and VEGFA normalized expression level in controls and EC tissue samples obtained from pre-menopausal and post-menopausal women; N/A, not available, N/S, not significant, *p < 0.05, ***p < 0.001; R, Spearman’s rank correlation coefficient

Fig. 13

Map of the HIF1A, EPAS1, and VEGFA interplay (cpb.molgen.de)