Sanaz Savabkar; Shiva Irani; Masoud Alebouyeh; Reza Mirfakhraie; Ehsan Nazemalhosseini Mojarad; Mohammad reza Zali; Hamid Asadzadeh aghdaei
Volume 23, Issue 4 , 2021
Abstract
Background: Aberrant DNA methylation is a common molecular feature in colorectal cancer (CRC). Hypermethylation of miR-200b promoter, as an epigenetic factor, is involved in CRC tumorigenesis. The methylation status of miR-200b has been examined in CRC and adjacent normal tissues.
Objectives: ...
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Background: Aberrant DNA methylation is a common molecular feature in colorectal cancer (CRC). Hypermethylation of miR-200b promoter, as an epigenetic factor, is involved in CRC tumorigenesis. The methylation status of miR-200b has been examined in CRC and adjacent normal tissues.
Objectives: This study aimed to investigate miR-200b methylation in a series of colorectal adenomatous polyps, hyperplastic polyps, and adenocarcinoma tissues as precursors of CRC in the Iranian population for the first time.
Materials and Methods: In this cross-sectional study (2017-2018), the methylation status of the miR-200b promoter was investigated using methylation-specific PCR in 131 fresh samples, including 30 adenocarcinoma specimens, 17 tumor-adjacent normal tissues, 78 primary lesions (55 adenomatous polyps and 23 hyperplastic polyps) and 6 healthy individuals.
Results: Methylation of miR-200b was detected in adenocarcinoma samples (86%) and adenomatous polyps (85%); however, most of the hyperplastic polyps were unmethylated (69.6%). Neither control individuals nor tumor-adjacent normal tissues exhibited methylation in the miR-200b promoter. Aberrant methylation of miR-200b was significantly more common in tumor tissues and adenomatous polyps than in hyperplastic polyps (P<0.0001) and tumor-adjacent normal samples (P<0.0001).
Conclusion: Methylation status of the miR-200b promoter was significantly altered during CRC development and may be identified as an attractive biomarker for the early detection of the disease.
Soraya Moamer; Ahmad Reza Baghestani; Mohamad Amin Pourhoseingholi; Ali Akbar Khadem Maboudi; Soodeh Shahsavari; Mohammad Reza Zali; Tahereh Mohammadi Majd
Volume 19, Issue 6 , June 2017, , Pages 1-8
Abstract
Background: In competing risks data, when a person experiences more than one event in the study, usually the probability of experiencing the event of interest is altered. Therefore, it is necessary to analyze the competing risk data.Objectives: The current study aimed at analyzing the colorectal cancer ...
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Background: In competing risks data, when a person experiences more than one event in the study, usually the probability of experiencing the event of interest is altered. Therefore, it is necessary to analyze the competing risk data.Objectives: The current study aimed at analyzing the colorectal cancer (CRC) risk factors based on competing risks model. The loglogistic model was also fitted with 2-parameter to evaluate the prognostic factors that affect the survival of patients with CRC, and comparisons were made to find the best model.Methods: The current retrospective study was conducted on 1054 patients with CRC registered in the Research Institute of gastroenterology and liver disease center (from 2004 to 2015), Taleghani hospital, Tehran, Iran. The demographic and clinical features including age at diagnosis, gender, family history of CRC, body mass index (BMI), tumor size, and tumor site were extracted from the hospital documents. Analysis was performed using competing risks model and was based on the 4-parameter log-logistic distribution and log-logistic distribution. The analysis was carried out using R software version 3.0.3. P value less than 0.05 was considered as significant.Results: Overall, 1054 patients with CRC and complete data were included in the analysis. The mean ± standard deviation (SD) of survival time was 92 ± 6.62 months. Out of the 1054 patients, 379 (36%) subjects died of CRC and 49 (4.6%) subjects died of other causes such as myocardial infarction, stomach cancer, liver cancer, etc. Four-parameter log-logistic model and log-logistic model with competing risk analysis indicated age at diagnosis and BMI as the prognosis.Conclusions: The current study indicated age and BMI as prognosis of CRC, using a 4-parameter log-logistic model with competing risk analysis. Although the odds ratio (OR) in 4-parameter log-logistic model and log-logistic model ones were approximately similar, according to Akaike information criterion, the 4-parameter log-logistic model was more appropriate for survival analysis.
