The tea catechin epigallocatechin-3-gallate (EGCG) proved to be the most potent physiologically active tea compound in vitro. It possesses antioxidant as well as pro-oxidant properties. EGCG has the effect of inducing apoptosis of tumor cells and inhibiting cell proliferation. Whether this effect is associated with the antioxidant or pro-oxidative effects of EGCG affecting the genome stability of normal and cancer cells has not been confirmed. Here, we selected Human normal colon epithelial cells NCM460 and colon adenocarcinoma cells COLO205 to investigate the effects of EGCG (0–40 μg/mL) on the genome stability and cell growth status. Chromosomal instability (CIN), nuclear division index (NDI), and apoptosis was measured by cytokinesis-block micronucleus assay (CBMN), and the expression of core genes in mismatch repair (hMLMLH1 and hMSH2) was examined by RT-qPCR. We found that EGCG significantly reduced CIN and apoptosis rate of NCM460 at all concentrations (5–40 μg/mL) and treatment time, EGCG at 5 μg/mL promoted cell division; EGCG could significantly induce chromosome instability in COLO205 cells and trigger apoptosis and inhibition of cell division. These results suggest that EGCG exhibits different genetic and cytological effects in normal and colon cancer cells.
Folate-mediated one-carbon metabolism (FMOCM) is linked to DNA synthesis, methylation, and cell proliferation. Vitamin B6 (B6) is a cofactor, and genetic polymorphisms of related key enzymes, such as serine hydroxymethyltransferase (SHMT), methionine synthase reductase (MTRR), and methionine synthase (MS), in FMOCM may govern the bioavailability of metabolites and play important roles in the maintenance of genomic stability and cell viability (GSACV). To evaluate the influences of B6, genetic polymorphisms of these enzymes, and gene–nutrient interactions on GSACV, we utilized the cytokinesis-block micronucleus assay (CBMN) and PCR-restriction fragment length polymorphism (PCR-RFLP) techniques in the lymphocytes from female breast cancer cases and controls. GSACV showed a significantly positive correlation with B6 concentration, and 48 nmol/L of B6 was the most suitable concentration for maintaining GSACV in vitro. The GSACV indexes showed significantly different sensitivity to B6 deficiency between cases and controls; the B6 effect on the GSACV variance contribution of each index was significantly higher than that of genetic polymorphisms and the sample state (tumor state). SHMT C1420T mutations may reduce breast cancer susceptibility, whereas MTRR A66G and MS A2756G mutations may increase breast cancer susceptibility. The role of SHMT, MS, and MTRR genotype polymorphisms in GSACV is reduced compared with that of B6. The results appear to suggest that the long-term lack of B6 under these conditions may increase genetic damage and cell injury and that individuals with various genotypes have different sensitivities to B6 deficiency. FMOCM metabolic enzyme gene polymorphism may be related to breast cancer susceptibility to a certain extent due to the effect of other factors such as stress, hormones, cancer therapies, psychological conditions, and diet. Adequate B6 intake may be good for maintaining genome health and preventing breast cancer.
MicroRNAs are small endogenous noncoding RNAs that have emerged as key negative regulators that target gene expression through RISC. Our previous study showed that the methylenetetrahydrofolate reductase gene (MTHFR) plays a key role in one carbon metabolism, which is downregulated by miR-22-3p and miR-149-5p, and that it could exert a potential anti-cancer effect. Whether miR-22-3p/miR-149-5p can regulate MTHFR to exert anti-cancer effects has become the focus of our research. Normal (HL-7702 cells) and cancerous (QGY-7703/HepG2 cells) human hepatocellular cells were transfected with 100 nM hsa-miR-22-3p/hsa-miR-149-5p mimic or controls. After 24, 48, and 72 h, cell proliferation ability was tested using CCK-8. The changes in MTHFR expression at both the transcriptional and translational levels were determined by RT-qPCR and Western blotting, respectively. Cancerous cell invasion and migration ability were confirmed by means of a transwell assay. We found that ectopic miR-22-3p/miR-149-5p inhibits hepatocellular carcinoma cell proliferation but does not inhibit normal human hepatocyte proliferation. The transfection of ectopic miR-22-3p/miR-149-5p downregulated the MTHFR expression in QGY-7703 and HepG2 but not in HL-7702. QGY-7703 and HepG2 migration and invasion were inhibited by ectopic miR-22-3p/miR-149-5p. Additionally, we found that ectopic miR-22-3p/miR-149-5p significantly increased the expression of TP53INP1 and PDCD4 in QGY-7703. The results of the study suggest that miRNA-22-3p and miRNA-149-5p inhibit tumor growth and metastasis properties may be by regulating MTHFR and that they exert anticancer effects in hepatocellular carcinoma cells.
Curcumin (CUR) and soy isoflavones (SIs) are two plant-based polyphenols that have attracted much attention, because of their extensive anticancer and health maintenance effects. However, the relevant molecular mechanisms are still uncertain. Genomic instability (GIN) refers to a combination of gene abnormal amplification, sequence deletion, ectopic, and other types of gene damage in cells, and it is one of the main factors causing cells to lose normal physiological functions. Therefore, we used the cytokinesis-block micronucleus cytome (CBMN-Cyt) assay as the main research method to analyze the effects of CUR and SIs on the GIN of human normal colon cells NCM460 and colon cancer cells SW620. Results show that CUR (12.5 μM) could reduce the apoptosis of NCM460 and maintain its genomic stability while inhibiting the proliferation of SW620 and promoting its apoptosis. There was no difference in the promoting effect of GIN between SW620 and NCM460 using SIs (3.125–50 μM). When the two polyphenols (v/v = 1/1, 1.5625–6.25 μM) were mixed, they could promote the proliferation and GIN of the NCM460 and SW620 cells, but we did not find that combining the two produced a better effect on the cells. In conclusion, CUR has more prominent health and anticancer effects, and it may become a dietary recommendation for daily health maintenance and a potential adjuvant drug for cancer treatment.
The use of intensity-modulated radiation therapy (IMRT) in postoperative cervical cancer is on the rise, yet there is still some controversy to adopt adjuvant IMRT as standard practice. The purpose of this study is to compare the difference between IMRT and three dimensional conformal radiation therapy (3D-CRT) especially in quality of life for pelvic radiation of postoperative treatment with cervical cancer.