Effects of Vitamin D Analogs Alfacalcidol and Calcitriol on Cell Proliferation and Migration of HEC1A Endometrial Adenocarcinoma Cells

Effect of VD3 on cell proliferation and the Wnt signaling pathway in bovine endometrial epithelial cells treated with lipopolysaccharide

Vitamin D (VD) deficiency plays an important role in the occurrence and development of various uterine diseases. At present, most studies on the mechanism of VD in the Wnt signaling pathway focus on cancer, while there are no relevant reports on its mechanism in endometritis. This study investigated the effect of vitamin D3 (VD3) on the Wnt signaling pathway in endometrial epithelial cells (BEECs) induced by lipopolysaccharide (LPS). BEECs obtained from bovine uteri were treated with VD3 (0, 50 ng/mL) and LPS (0, 10, 100 ng/mL) separately or in combination, and treated with the Wnt signaling pathway inhibitor IWR-1 to study the mechanism of action. The proliferation of BEECs was evaluated by a CCK-8 assay. qRT-PCR was used to assess the gene expression of Wnt pathway-related factors, including MYC, PCNA, LGR5, GREM1, β-catenin, FZD7, FZD2, Wnt4 and VDR. The results showed that VD3 had no significant effect on cell proliferation (P > 0.05); LPS inhibited BEEC proliferation in a time- and dose-dependent manner, and cells treated with LPS at different concentrations for 24-48 h in combination with VD3 promoted cell proliferation to varying degrees. IWR-1 inhibited cell proliferation in a time- and concentration-dependent manner, while LPS + IWR-1 treatment also significantly promoted cell proliferation after VD3 treatment (P < 0.01). The qRT-PCR results showed that the expression of Wnt4 and PCNA genes showed different trends with different LPS concentrations for stimulation, and the expression of the MYC and GREM1 genes was only stimulated by high-dose (100 ng/mL) LPS stimulation. The expression of FZD7, LGR5, FZD2 and β-catenin was upregulated by LPS at both concentrations. LPS + VD3 significantly downregulated the expression of the Wnt pathway-related genes MYC, PCNA, LGR5, GREM1 and β-catenin (P < 0.001), Wnt4 and FZD2 (P < 0.01), and significantly upregulated the expression of VDR (P < 0.05). After LPS + IWR-1 treatment, the expression of the β-catenin (P < 0.01) and LGR5 (P < 0.05) genes was significantly downregulated, while the Wnt4 (P < 0.01) and VDR (P < 0.001) genes were significantly upregulated, MYC was downregulated but without a significant difference (P > 0.05). In conclusion, VD3 treatment can mitigate the LPS-induced abnormal expression of Wnt signaling pathway genes in BEECs, showing that the Wnt pathway may be a protective pathway of VD3 against LPS-induced gene overexpression in BEECs. The results suggest that VD3 may play a regulatory role in pathways other than the Wnt signaling pathway. Whether VD3 affects the Wnt signaling pathway by affecting Wnt4 gene expression requires further study.

A Narrative Review of the Role of Diet and Lifestyle Factors in the Development and Prevention of Endometrial Cancer

Simple Summary

The incidence and prevalence of endometrial cancer is increasing globally. The main factors involved in this increase have been the way women live today and what they eat and drink. In fact, the obesity pandemic that is sweeping across the planet is considered to be the main contributory feature. This review aims to introduce to a new audience, those that are not experts in the field, what is known about the different types of endometrial cancer and the mechanisms for their induction and protection. We also seek to summarise the existing knowledge on dietary and lifestyle factors that prevent endometrial development in susceptible populations and identify the main problem in this arena; the paucity of research studies and clinical trials that investigate the interaction(s) between diet, lifestyle and endometrial cancer risk whilst highlighting those areas of promise that should be further investigated.

Abstract

Endometrial cancer is the most common cancer affecting the reproductive organs of women living in higher-income countries. Apart from hormonal influences and genetic predisposition, obesity and metabolic syndrome are increasingly recognised as major factors in endometrial cancer risk, due to changes in lifestyle and diet, whereby high glycaemic index and lipid deposition are prevalent. This is especially true in countries where micronutrients, such as vitamins and minerals are exchanged for high calorific diets and a sedentary lifestyle. In this review, we will survey the currently known lifestyle factors, dietary requirements and hormonal changes that increase an individual’s risk for endometrial cancer and discuss their relevance for clinical management. We also examine the evidence that everyday factors and clinical interventions have on reducing that risk, such that informed healthy choices can be made. In this narrative review, we thus summarise the dietary and lifestyle factors that promote and prevent the incidence of endometrial cancer.