Background: N6‐methyladenosine (m6A) modification may participate in the regulation of occurrence and development of tumors. However, the m6A level and the potential regulatory mechanism of m6A in gastric cancer (GC) remain uncertain.Methods: RNA m6A quantification assay was conducted to detect the m6A level in GC tissues and cell lines. Methyltransferase‐like 14 (METTL14) expression in GC tissues was explored by bioinformatics and immunohistochemistry. Then, the function of METTL14 in GC cells was examined by CCK‐8, colony formation assay, wound healing assay, and Transwell assay. Besides, Western blotting was conducted to probe the PI3K/AKT/mTOR pathway and the epithelial‐mesenchymal transformation (EMT) pathway‐related gene expression.Results: The m6A modification level was decreased in GC and METTL14 was a key regulator resulting in m6A disorder in GC. METTL14 was downregulated in GC by analyzing both clinical samples and bioinformatics. METTL14 overexpression suppressed GC cell proliferation and aggression by deactivating the PI3K/AKT/mTOR pathway and the EMT pathway, respectively.Conclusions: Our findings indicate that METTL14 partakes in the biological process of GC as a tumor suppressor and may be an emerging biomarker in GC.
Bisphenol A (BPA) and di-(2-ethylhcxyl) phthalate (DEHP) are exist widespread in the environment and produce adverse effect to human as environmental disruptors (EDCs). Epidemiological studies have found that the exposure of DEHP and BPA could increase the susceptibility to thyroid diseases including thyroid cancer and benign thyroid nodules. Due to the existence of multiple pollutants in our daily life, the mixed toxic effects of exposure and their interrelationships may distinguish from the exposure to a single chemical, so it is of great significance to explore the mixed toxic effect of DEHP and BPA co-exposure. Thyroid, as one of the target organs of EDCs, is prone to tumor occurrence, however, whether the mixture of BPA and DEHP will affect the occurrence of thyroid cancer is still obscure. We aim to investigate the effect of single or combined exposure to BPA and DEHP on the occurrence of thyroid cancer. An animal model of exposure to BPA and DEHP was firstly established to evaluate their effect on DMD-induced thyroid cancer. Additionally, human thyroid cancer cells BCPAP and thyroid cells Nthy-ori3-1 were used to further clarify some possible mechanisms of BPA and MEHP, the main metabolite of DEHP. Consequently, we found that BPA alone could increase the incidence of thyroid tumors in female rats compared with DEHP, and DEHP enhanced the effect of BPA on cancer promotion. BPA alone and in combination with DEHP mainly induced the expression of HDAC6, inhibited tumor suppressor gene PTEN upregulated the expression of oncogene c-MYC, and eventually elevate the susceptibility to thyroid tumors. Mechanistically, BPA alone and in combination with MEHP could significantly induce the proliferation of BCPAP cells depending on HDAC6, which could modulate H3K9ac to inhibit PTEN, activate AKT signaling pathway, and simultaneously upregulate the expression of c-MYC. Interestingly, we found that BPA alone and in combination with MEHP could significantly induce the proliferation of Nthy-ori3-1 cells independent on HDAC6 via activating ERK signaling pathway. Taken together, these findings not only provide new evidence of the promoting effect of BPA and DEHP on thyroid cancer but also discusses some possible mechanisms underlying these effects.
1 September 2021 in Ecotoxicology and Environmental Safety
Breast cancer (BrCa) as one of the major malignancies threatening women's health worldwide occurs due to the genetic and environmental interactions. Epidemiological studies have suggested that exposure to endocrine disrupting chemicals (EDCs) can elevate the risk of breast cancer. Di-(2-ethylhexyl)-phthalate (DEHP) and bisphenol A (BPA) are known as two typical EDCs. Although several studies have implied that there appear to have adverse effects of exposure to BPA or DEHP alone on breast development, no study to date has demonstrated the exact toxic effect of combined exposure to DEHP and BPA on breast tumorigenesis. In the present study, we performed an in vivo experiment including 160 female Sprague-Dawley (SD) rats, in which 80 rats were randomly allocated to 4 groups including control group given to normal diet, DEHP (150 mg/kg body weight/day), BPA (20 mg/kg body weight/day), and DEHP (150 mg/kg body weight/day) combined with BPA (20 mg/kg body weight/day) by gavage for 30 weeks. Additionally, a DEN/MNU/DHPN (DMD)-induced carcinogenesis animal model was also established to assess their effect on tumor promotion. Namely, the other 80 SD rats were separated into another 4 groups: in addition to DMD initiation each group treated with vehicle, DEHP, BPA and the combination of BPA and DEHP respectively. Our data demonstrated that BPA alone or in combination with DEHP may induce hyperplasia of mammary glands, including the proliferation of ductal epithelial cells and an increase in the number of lobules and acinus after a 30-week exposure. Notably, co-exposure to DEHP and BPA increased the incidence and reduced the latency of mammary tumor, which seemed to enhance the susceptibility of carcinogens-induced tumor. Mechanistically, our results supported the hypothesis that exposure to BPA and DEHP might promote breast cancer dependent on Esr1 and HDAC6 as pivotal factors, and further lead to the activation of oncogene c-Myc. Our study suggested that BPA combined with DEHP facilitate the occurrence of mammary tumors, which contributed to advance our understanding in the complex effects of compound exposure to endocrine disrupting chemicals.
Single nucleotide polymorphisms (SNPs) in 3′UTR of key DNA repair enzyme genes are associated with inter‐individual differences of DNA repair capacity (DRC) and susceptibility to a variety of human malignancies such as lung cancer. In this study, seven candidate SNPs in 3′UTR of DRC‐related genes including ERCC1 (rs3212986, rs2336219, and rs735482), OGG1 (rs1052133), MLH3 (rs108621), CD3EAP (rs1007616), and PPP1R13L (rs6966) were analyzed in 300 lung cancer patients and controls from the northeast of China. Furthermore, we introduced ERCC1 (CDS+3′UTR) or CD3EAP (CDS) cDNA clone to transfect HEK293T and 16HBE cells. Cell viability between different genotypes of transfected cells exposed to BPDE was detected by CCK‐8 assay, while DNA damage was visualized using γH2AX immunofluorescence and the modified comet assay. We found that minor A‐allele of rs3212986 could reflect a linkage with increasing risk of NSCLC. Compared with CC genotype, AA genotype of ERCC1 rs3212986 was a high‐risk factor for NSCLC (OR = 3.246; 95%CI: 1.375‐7.663). Particularly stratified by smoking status in cases and controls, A allele of ERCC1 rs3212986 also exhibited an enhanced risk to develop lung cancer in smokers only (P < 0.05). Interestingly, reduced repair efficiency of DNA damage was observed in 293T ERCC1(AA) and 16HBE ERCC1(AA), while no significant difference was appeared in two genotypes of CD3EAP (3′ adjacent gene of ERCC1) overexpressed cells. Our findings suggest that rs3212986 polymorphism in 3ʹUTR of ERCC1 overlapped with CD3EAP may affect the repair of the damage induced by BPDE mainly via regulating ERCC1 expression and become a potential biomarker to predict smoking‐related lung cancer.
12 May 2023 in Environmental Science and Pollution Research
Environmental pollution seriously affects human health. The concentration of negative air ions (NAIs), which were discovered at the end of the nineteenth century, is one of the factors used to evaluate air quality. Additionally, NAIs have been widely considered markers by scholars due to their unique biological function. The aim of this study was to summarize existing research and propose future research on the generation and temporal and spatial dynamic patterns of NAIs concentrations as well as the relationship between NAIs and human health. We identified 187 studies (published January 2013–January 2023) that met our inclusion criteria. Fourteen English studies evaluated the effects of NAIs on depression, the cardiovascular system, the respiratory system, reproduction and development, cognition, and sports muscle injury. Only two studies reported the associations of NAIs exposure with metabolic omics. NAIs concentrations vary temporally with solar radiation, air temperature, and relative humidity, while the temporal dynamic patterns of NAIs are affected by season, time, meteorological factors, air quality index, geographical location, forest vegetation, and other factors. Researchers have shown that exposure to NAIs may benefit our health by changing amino acid metabolism, which mainly manifests as increased anti-inflammation and reduced inflammation and antioxidation. Furthermore, exposure to NAIs promotes energy production, affects the expression of c-fos, and regulates 5-HT levels. There has been considerable interest in the potential effects of NAIs on human health and well-being, but the conclusions have been inconsistent and the mechanisms remain unclear. The use of omics to elucidate the biological mechanism of NAIs is relatively new and has some advantages. Graphical Abstract
Lanthanum (La) exposure can lead to learning and memory disorder in animals; however, the underlying mechanism of La induced neurotoxicity is still unknown.