BackgroundMutations and promoters' methylation of a set of candidate cancer genes (CAN genes) are associated with progression of colorectal cancer (CRC). We hypothesized that these genes' promoters are inactivated through epigenetic silencing and may show a different profile in high-risk populations. We investigated the status of CAN gene methylation and CHD5 protein expression in African American CRC tissue microarrays (TMA) using immunohistochemical staining.Methodology/Principal FindingsThe promoter methylation status of the CAN genes was studied by methylation-specific PCR (MSP) in 51 Iranians (a white population) and 51 African Americans (AA). Microsatellite instability (MSI) was analyzed as well. The differential frequency of methylation for each gene was tested by chi-square analysis between the two groups based on matched age and sex. CHD5 protein expression was evaluated in moderate to well differentiated and poorly differentiated carcinomas compared to matched normal tissue using TMA. In addition, the correlation between these epigenetic biomarkers and various clinicopathological factors, including, age, location, and stage of the disease were analyzed.Seventy-seven and 34% of tumors were distal in Iranian and African American patients, respectively. In both populations, the percentage of methylation was >65% for SYNE1, MMP2, APC2, GPNMB, EVL, PTPRD, and STARD8, whereas methylation was <50% for LGR6, RET, CD109, and RNF. The difference in methylation between the two populations was statistically significant for CHD5, ICAM5 and GPNMB. Thirty-one percent AA tumors showed MSI-H, compared to 28% in Iranians.Conclusions/SignificanceA significantly higher methylation rate was found for GPNMB, ICAM5, and CHD5 genes in AA patients compared to Iranians. These genes might play a role in the high incidence and aggressiveness of CRC in the AA population. The hypermethylation of the CAN genes can be considered as a marker of colon carcinogenesis.
Colorectal cancer (CRC), despite numerous therapeutic and screening attempts, still remains a major life-threatening malignancy. CRC etiology entails both genetic and environmental factors. Macroautophagy/autophagy and the unfolded protein response (UPR) are fundamental mechanisms involved in the regulation of cellular responses to environmental and genetic stresses. Both pathways are interconnected and regulate cellular responses to apoptotic stimuli. In this review, we address the epidemiology and risk factors of CRC, including genetic mutations leading to the occurrence of the disease. Next, we discuss mutations of genes related to autophagy and the UPR in CRC. Then, we discuss how autophagy and the UPR are involved in the regulation of CRC and how they associate with obesity and inflammatory responses in CRC. Finally, we provide perspectives for the modulation of autophagy and the UPR as new therapeutic options for CRC treatment.
We have identified an alternative pathway of tumorigenesis in sporadic colon cancer, involving microsatellite instability due to mismatched repair methylation, which may be driven by mutations in the BRAF gene (V600E). Colorectal cancer (CRC) is the most common cancer in the world, and African Americans show a higher incidence than other populations in the United States. We analyzed sporadic CRCs in Omani (of African origin, N = 61), Iranian (of Caucasian origin, N = 53) and African American (N = 95) patients for microsatellite instability, expression status of mismatched repair genes (hMLH1, hMSH2) and presence of the BRAF (V600E) mutation. In the Omani group, all tumors with BRAF mutations were located in the left side of the colon, and for African Americans, 88% [7] of tumors with BRAF mutations were found in the right side of the colon. In African Americans, 31% of tumors displayed microsatellite instability at two or more markers (MSI-H), while this rate was 26% and 13% for tumors in the Iranian and Omani groups, respectively. A majority of these MSI-H tumors were located in the proximal colon (right side) in African American and Iranian subjects, whereas most were located in the distal colon (left side) in Omani subjects. Defects in hMLH1 gene expression were found in 77% of MSI-H tumors in both African Americans and Iranians and in 38% of tumors in Omanis. BRAF mutations were observed in all subjects: 10% of tumors in African Americans (8/82), 2% of tumors in Iranians (1/53), and 19% of tumors in Omanis (11/59). Our findings suggest that CRC occurs at a younger age in Omani and Iranian patients, and these groups showed a lower occurrence of MSI-H than did African American patients. Our multivariate model suggests an important and significant role of hMLH1 expression and BRAF mutation in MSI-H CRC in these populations. The high occurrence of MSI-H tumors in African Americans may have significant implications for treatment, since patients with MSI-H lesions display a different response to chemotherapeutic agents such as 5-fluorouracil.
Background Human leptin is a peptide hormone that is released from white adipocytes. The absence of leptin or its receptor leads to uncontrolled food intake, leading to obesity. In the present work, the effects of auricular acupressure combined with low-calorie diet on the leptin hormone level were investigated. Methods Volunteers (n=86) with body mass indices (BMI) between 25 and 45 kg/m 2 were randomised into a case (n=43) or a control (n=43) group. Participants in each group received a low-calorie diet for 6 weeks. The case group was treated with auricular acupressure and the control group received a sham procedure. Plasma leptin levels, body fat mass, body weight and BMI were measured before and after treatment. Results Participants who received auricular acupressure showed signifi cant reductions in their plasma leptin levels (18.57%, p<0.01) as well as in their body fat mass (4%, p<0.05). These changes were not observed in the control group. The reduction in leptin was signifi cantly greater in the acupressure group than the controls. Conclusions Auricular acupressure combined with a low-calorie diet signifi cantly reduced plasma levels of leptin. However, the mechanism of this reduction is not clear.
BackgroundThe prevalence of abdominal obesity is on the rise worldwide. Previous studies have indicated the higher diagnostic value of body fat distribution pattern compared with general body in abdominal obesity assessments. Several non-pharmacological methods have been suggested for obesity management, of which acupuncture has gained a great deal of research interest with promising results.This study aimed to comparatively evaluate the effects of conventional auricular and body electroacupuncture on abdominal fat mass in obese men.MethodsThe volunteers were randomly divided into four groups, including 2 interventions and 2 controls. This study was conducted on 80 obese volunteer men with Body Mass Index (BMI) range of 30–40 kg/m2.The intervention groups including real body electroacupuncture (A), real auricular acupuncture (C) and the control groups containing sham body electroacupuncture (B), and sham auricular acupuncture (D). All groups were in combination with a low-calorie diet for 6 weeks. BMI, Trunk Fat Mass (TFM), Waist Circumference (WC), and Hip Circumference (HC) were measured pre- and post-intervention.ResultsIn group A, respectively a significant reduction was shown in BMI (P < 0.005), TFM (P < 0.005), WC (P < 0.05, P < 0.005) and HC (P < 0.005) when compared with controls (Groups B and D). Interestingly, group C had significant decreases in BMI (P < 0.005), TFM (P < 0.01, P < 0.005), WC (P < 0.005) and HC (P < 0.001) after comparison with the sham. Likewise, WC (P < 0.05) and HC (P < 0.05) were significantly reduced post- intervention when compared with two treatment groups.ConclusionsIn our study, acupuncture treatment (body or auricular) seemed to have an effect on reducing BMI, TFM, WC and HC. Comparison of the two types of treatment (body and auricular acupuncture) suggests that the two types of acupuncture had similar effects on reducing BMI and TFM, but body electroacupuncture is more effective in reducing WC and auricular in HC. It seems that both auricular and body electro-acupuncture combined with a low-calorie diet are efficient, simple and painless methods to reduce respectively the HC and WC fat in obese men, compared with conventional techniques.Trial registrationIRCT201201127117N2
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