Methylation analysis of MIR200 family in Mexican patients with colorectal cancer.

The present study aimed to analyze the methylation pattern of the MIR200 family in the colorectal tissues and peripheral blood of colorectal cancer (CRC) patients. Previous informed consent, 102 samples of colorectal tissues (tumor and adjacent normal tissues) and 40 peripheral blood samples were collected from CRC patients. Additionally, we included a reference group of 40 blood samples. DNA extraction was done for colorectal tissues and peripheral blood. For methylation-specific PCR, we used bisulfite-treated DNA and controls for methylated and unmethylated DNA were included to each assay. PCR fragments were separated by 6% polyacrylamide gel electrophoresis. Methylation-positive and methylation-negative results were confirmed by bisulfite genomic sequencing technique. We analyzed 102 colorectal tissues and 40 blood samples from 51 CRC patients. MIR200B/MIR200A/MIR429 methylation analysis discloses no differences among tissues (p>0.05). However, MIR200C/MIR141 methylation showed differences between colorectal tissues and peripheral blood of CRC patients (p<0.0001) and mainly methylated alleles were observed in peripheral blood. These findings suggest a tissue-specific methylation pattern for the MIR200C/MIR141 promoter.

Incidence and prevalence of inflammatory bowel disease in Mexico from a nationwide cohort study in a period of 15 years (2000-2017).

Despite the worldwide increasing incidence and prevalence of Inflammatory Bowel Disease (IBD), our knowledge about it in Mexico is still limited. The aim of this study is to describe the incidence and prevalence of IBD as well as its clinical and socio-demographical characteristics in Mexico from a nation-wide perspective.Multicenter nation-wide cohort study that included 42 IBD clinics from all over the country that participated with electronically register of the new cases over 17 years as well as all known existing cases together with their clinical and socio-demographical characteristics from patients with IBD (ulcerative colitis [UC], Crohn disease [CD], and inflammatory bowel disease unclassified [IBDU]). The data collection was conducted between January and October 2017. Incidence, prevalence, and mean incidence over 2 decades were then calculated. Data base was analyzed using SPSS v24 program SPSS (version 24, IBM Corp., Armonk, NY, USA).A total of 2645 patients with IBD were registered. The crude incidence rates of IBD, UC, and CD, respectively, were 0.21, 0.16, and 0.04 cases per 100,000-person year. The highest incidence was registered in the year 2015, compared with to the previous years. The mean incidence of IBD has increased steadily from 0.05 to 0.21 per 100,000 person-years over the past 15 years (P = .06). The incidence of IBD new cases have increased significantly throughout the last 16 years, 5.9-fold for IBD, 5.3-fold for UC, and 9.5-fold for CD. The prevalence rates of IBD, UC, and CD, respectively, were 1.83, 1.45, and 0.34 cases per 100,000-person-year.This is the first study from a nation-wide perspective that demonstrated a significant increase of prevalence and incidence of IBD in Mexico in the last 15 years.