Amir Torshizi Esfahani1, Seyed Yoosef Seyedna1, Ehsan Nazemalhosseini Mojarad2, Ahmad Majd3, Hamid Asadzadeh Aghdaei4. 1. Department of Biology, Faculty of Biological Sciences, Islamic Azad University, North Tehran Branch, Tehran, Iran. 2. Department of Cancer, Gastroenterology and Liver Diseases Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 3. Department of Molecular Medicine, Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Islamic Azad University, North Tehran Branch, Tehran, Iran. 4. Basic and Molecular Epidemiology of Gastrointestinal Disorders Research Center, Research Institute for Gastroenterology and Liver Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Abstract
BACKGROUND: Microsatellite instability (MSI) is a prognostic marker in colorectal cancer (CRC). The biological significance of MSI-low (MSI-L) phenotype and its differences with microsatellite stable (MSS) phenotype remains unclear. The aim of this study is indicating the role of mononucleotide repeat in identifying MSI-L and revealing the association of MSI-L with elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) and oncologic outcome in CRC patients. METHODS: MSI and EMAST status were analyzed using three quasimonomorphic panel (BAT-25, BAT-26, and NR-27) and five tetranucleotide repeats (D20S82, D20S85, D9S242, D8S321, and MYCL1), respectively, by capillary electrophoresis method without the need to fluorescent primers. The associations of MSI status with clinicopathological features, EMAST status, metastasis, and overall survival (OS) were investigated. RESULTS: Among 159 CRC patient 22.0% were MSI-H, 40.3% were MSS, 37.7% were MSI-L, and 41.5% showed EMAST + phenotype. MSI-L were associated with advanced stages, EMAST+ tumors and worse OS ( p ≤ 0.001). Metastasis was relatively common in MSI-L/EMAST + CRCs and BAT-25 were the most unstable marker in these tumors. CONCLUSIONS: MSI-L tumors have different clinicopathological features from MSS and MSI-H tumors. The MSI-L phenotype is a worse prognostic biomarker in CRC and when accompanied by EMAST could be a predictor for metastasis.
BACKGROUND:Microsatellite instability (MSI) is a prognostic marker in colorectal cancer (CRC). The biological significance of MSI-low (MSI-L) phenotype and its differences with microsatellite stable (MSS) phenotype remains unclear. The aim of this study is indicating the role of mononucleotide repeat in identifying MSI-L and revealing the association of MSI-L with elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) and oncologic outcome in CRCpatients. METHODS: MSI and EMAST status were analyzed using three quasimonomorphic panel (BAT-25, BAT-26, and NR-27) and five tetranucleotide repeats (D20S82, D20S85, D9S242, D8S321, and MYCL1), respectively, by capillary electrophoresis method without the need to fluorescent primers. The associations of MSI status with clinicopathological features, EMAST status, metastasis, and overall survival (OS) were investigated. RESULTS: Among 159 CRCpatient 22.0% were MSI-H, 40.3% were MSS, 37.7% were MSI-L, and 41.5% showed EMAST + phenotype. MSI-L were associated with advanced stages, EMAST+ tumors and worse OS ( p ≤ 0.001). Metastasis was relatively common in MSI-L/EMAST + CRCs and BAT-25 were the most unstable marker in these tumors. CONCLUSIONS:MSI-L tumors have different clinicopathological features from MSS and MSI-H tumors. The MSI-L phenotype is a worse prognostic biomarker in CRC and when accompanied by EMAST could be a predictor for metastasis.
Authors: GiWon Shin; Stephanie U Greer; Erik Hopmans; Susan M Grimes; HoJoon Lee; Lan Zhao; Laura Miotke; Carlos Suarez; Alison F Almeda; Sigurdis Haraldsdottir; Hanlee P Ji Journal: Genome Med Date: 2021-09-06 Impact factor: 11.117
Authors: Sabine Meessen; Nicola Currey; Zeenat Jahan; Hannah W Parker; Mark A Jenkins; Daniel D Buchanan; John L Hopper; Eva Segelov; Jane E Dahlstrom; Maija R J Kohonen-Corish Journal: Cancers (Basel) Date: 2021-07-14 Impact factor: 6.639