scholarly journals Tetranucleotide and Low Microsatellite Instability Are Inversely Associated with the CpG Island Methylator Phenotype in Colorectal Cancer

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3529
Author(s):  
Sabine Meessen ◽  
Nicola Currey ◽  
Zeenat Jahan ◽  
Hannah W. Parker ◽  
Mark A. Jenkins ◽  
...  

MSH3 gene or protein deficiency or loss-of-function in colorectal cancer can cause a DNA mismatch repair defect known as “elevated microsatellite alterations at selected tetranucleotide repeats” (EMAST). A high percentage of MSI-H tumors exhibit EMAST, while MSI-L is also linked with EMAST. However, the distribution of CpG island methylator phenotype (CIMP) within the EMAST spectrum is not known. Five tetranucleotide repeat and five MSI markers were used to classify 100 sporadic colorectal tumours for EMAST, MSI-H and MSI-L according to the number of unstable markers detected. Promoter methylation was determined using methylation-specific PCR for MSH3, MCC, CDKN2A (p16) and five CIMP marker genes. EMAST was found in 55% of sporadic colorectal carcinomas. Carcinomas with only one positive marker (EMAST-1/5, 26%) were associated with advanced tumour stage, increased lymph node metastasis, MSI-L and lack of CIMP-H. EMAST-2/5 (16%) carcinomas displayed some methylation but MSI was rare. Carcinomas with ≥3 positive EMAST markers (13%) were more likely to have a proximal colon location and be MSI-H and CIMP-H. Our study suggests that EMAST/MSI-L is a valuable prognostic and predictive marker for colorectal carcinomas that do not display the high methylation phenotype CIMP-H.

Cancers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3487
Author(s):  
Shih-Ching Chang ◽  
Anna Fen-Yau Li ◽  
Pei-Ching Lin ◽  
Chun-Chi Lin ◽  
Hung-Hsin Lin ◽  
...  

Background: The 5’-C-phosphate-G-3’ island methylator phenotype (CIMP) is a specific phenotype of colorectal cancer (CRC) associated with microsatellite instability-high (MSI-high) tumors. Methods: In this study, we determined the CIMP status using eight methylation markers in 92 MSI-high CRC patients after excluding five germline mismatch repair (MMR) gene mutations analyzed by next-generation sequencing (NGS) and confirmed by Sanger sequencing. The mutation spectra of 22 common CRC-associated genes were analyzed by NGS. Results: Of the 92 sporadic MSI-high tumors, 23 (25%) were considered CIMP-high (expressed more than 5 of 8 markers). CIMP-high tumors showed proximal colon preponderance and female predominance. The mutation profiles of CIMP-high tumors were significantly different from those of CIMP-low or CIMP-0 tumors (i.e., higher frequencies of BRAF, POLD1, MSH3, and SMAD4 mutations but lower frequencies of APC, TP53, and KRAS mutations). Multivariate analysis demonstrated that tumor, node, metastasis (TNM) stage was the independent prognostic factor affecting overall survival (OS). Among the MSI-high cases, the CIMP status did not impact the outcome of patients with MSI-high tumors. Conclusions: Only TNM stage was a statistically significant predictor of outcomes independent of CIMP profiles in MSI-high CRC patients. Sporadic MSI-high CRCs with different mechanisms of carcinogenesis have specific mutation profiles and clinicopathological features.


2020 ◽  
Vol 4 (5) ◽  
Author(s):  
Julia D Labadie ◽  
Tabitha A Harrison ◽  
Barbara Banbury ◽  
Efrat L Amtay ◽  
Sonja Bernd ◽  
...  

Abstract Background Postmenopausal hormone therapy (HT) is associated with a decreased colorectal cancer (CRC) risk. As CRC is a heterogeneous disease, we evaluated whether the association of HT and CRC differs across etiologically relevant, molecularly defined tumor subtypes and tumor location. Methods We pooled data on tumor subtypes (microsatellite instability status, CpG island methylator phenotype status, BRAF and KRAS mutations, pathway: adenoma-carcinoma, alternate, serrated), tumor location (proximal colon, distal colon, rectum), and HT use among 8220 postmenopausal women (3898 CRC cases and 4322 controls) from 8 observational studies. We used multinomial logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CIs) for the association of ever vs never HT use with each tumor subtype compared with controls. Models were adjusted for study, age, body mass index, smoking status, and CRC family history. All statistical tests were 2-sided. Results Among postmenopausal women, ever HT use was associated with a 38% reduction in overall CRC risk (OR =0.62, 95% CI = 0.56 to 0.69). This association was similar according to microsatellite instability, CpG island methylator phenotype and BRAF or KRAS status. However, the association was attenuated for tumors arising through the serrated pathway (OR = 0.81, 95% CI = 0.66 to 1.01) compared with the adenoma-carcinoma pathway (OR = 0.63, 95% CI = 0.55 to 0.73; Phet =.04) and alternate pathway (OR = 0.61, 95% CI = 0.51 to 0.72). Additionally, proximal colon tumors had a weaker association (OR = 0.71, 95% CI = 0.62 to 0.80) compared with rectal (OR = 0.54, 95% CI = 0.46 to 0.63) and distal colon (OR = 0.57, 95% CI = 0.49 to 0.66; Phet =.01) tumors. Conclusions We observed a strong inverse association between HT use and overall CRC risk, which may predominantly reflect a benefit of HT use for tumors arising through the adenoma-carcinoma and alternate pathways as well as distal colon and rectal tumors.


2010 ◽  
Vol 16 (6) ◽  
pp. 1845-1855 ◽  
Author(s):  
Anna M. Dahlin ◽  
Richard Palmqvist ◽  
Maria L. Henriksson ◽  
Maria Jacobsson ◽  
Vincy Eklöf ◽  
...  

2006 ◽  
Vol 8 (5) ◽  
pp. 582-588 ◽  
Author(s):  
Shuji Ogino ◽  
Takako Kawasaki ◽  
Gregory J. Kirkner ◽  
Massimo Loda ◽  
Charles S. Fuchs

2009 ◽  
Vol 31 (3) ◽  
pp. 342-349 ◽  
Author(s):  
Hiromu Suzuki ◽  
Shinichi Igarashi ◽  
Masanori Nojima ◽  
Reo Maruyama ◽  
Eiichiro Yamamoto ◽  
...  

2021 ◽  
Vol 2 (3) ◽  
pp. 35-67
Author(s):  
Gargi Bhattacharyya ◽  
Amit Chattopadhay

Colorectal cancer (CRC) accounts for about 10% of cancer-related mortality in western countries. Increasing ageing population, undesirable modern dietary and high-risk factors like smoking, obesity and low exercise. Chromosomal instability (CIN), CpG island methylator phenotype (CIMP), and microsatellite instability are the three different mechanism that give rise to CRC. It often grow slowly, and customarily doesn’t produce symptoms until reaching a substantial size of several centimeters, which can block the passage of feces and cause cramping, pain, or bleeding which can present as visible bleeding with bowel movements or, rarely, dark “tarry” stools. Most colon tumors develop via a several different processes involving a series of histological, morphological, and genetical changes that accumulate over time to time. New treatments for primary and metastatic colorectal cancer have emerged, like in variety of therapeutic process by preparing chimeric proteins that triggers the cells and stop it from getting severe.


2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Catherine E. Bond ◽  
Vicki L. J. Whitehall

TheBRAFoncogene is an integral component of the MAP kinase pathway, and an activating V600E mutation occurs in 15% of sporadic colorectal cancer. This is an early event in serrated pathway tumourigenesis, and theBRAFV600E has been commonly associated with the CpG island methylator phenotype, microsatellite instability (MSI), and a consistent clinical presentation including a proximal location and predilection for elderly females. A proportion of theBRAFmutant lesions remain as microsatellite stable (MSS), and in contrast to the MSI cancers, they have an aggressive phenotype and correlate with poor patient outcomes. Recent studies have found that they have clinical and molecular features of both theBRAFmutant/MSI and the conventionalBRAFwild-type cancers and comprise a distinct colorectal cancer subgroup. This review highlights the importance of theBRAFmutation occurring in colorectal cancer stratified for molecular background and discusses its prognostic and clinical significance.


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