배정모 교수

Loss of CDX2 expression is associated with aggressive clinical behavior and can be used as a prognostic marker in CRCs.

-Because colorectal cancers arise from 2 different morphologic multistep carcinogenesis pathways with varying contributions from 3 different molecular carcinogenesis pathways, colorectal cancer is a heterogeneous and complex disease. Thus, molecular subtyping of colorectal cancers is an important approach to characterizing their heterogeneity with respect to not only prognosis and therapeutic response but also biology and natural history.

Several previous studies have demonstrated that the CDX2-negative (CDX2) and/or CK20-negative (CK20) phenotypes of colorectal cancers (CRCs) might be associated with high levels of microsatellite instability (MSI-H). The aim of this study was to investigate the clinicopathologic and molecular features of MSI-H CRCs with different CDX2/CK20 expression statuses. The CDX2 and CK20 expression statuses were immunohistochemically evaluated in 109 MSI-H CRC tissue samples, and the correlations of these

Focal CpG island hypermethylation and diffuse genomic hypomethylation signify the changes in the DNA methylation status in cancer cells. ALU and LINE-1 repetitive DNA elements comprise ~28% of the human genome. PCR-based measurements of these repetitive DNA elements can be used as a surrogate marker of the genomewide methylation content. Our study aimed to identify the timing of ALU and LINE-1 hypomethylations during multistep gastric carcinogenesis and their prognostic implications in gastric c

CIMP subtypes classified using our revised system showed different clinical outcomes, demonstrating the heterogeneity of multiple serrated precursors of CIMP-positive CRCs.

Our findings suggest that microsatellite instability plays a more important role than does epigenetic instability in the development of synchronous colorectal cancers, and that information regarding concordant or discordant microsatellite instability status between individual tumors might help to predict clinical outcome of synchronous colorectal cancers.

DNA methylation is one of the key mechanisms of epigenetic modification, and genome-wide hypomethylation and CpG island hypermethylation are characteristics of cancer cells. The CpG island methylator phenotype (CIMP) is a distinctive subtype of colorectal cancers (CRCs) that show concordant hypermethylation of numerous promoter CpG island loci. CIMP-positive CRCs are associated with a proximal location in the colon, microsatellite instability, BRAF mutation and a relatively poor clinical outcome

FGFR1 amplification measured by ddPCR can be a prognostic indicator of poor clinical outcome in patients with CRCs.

Annexin A10 expression is associated with poor clinical behavior and can be used a supportive surrogate marker of the serrated neoplasia pathway in invasive CRCs.

Our study confirmed that the frequency and characteristics of aberrant TTF-1 expression in CRCs vary according to the antibody clone. Aberrant TTF-1 expression detected by clone SPT24 or SP141 may be encountered preferentially in distally located, conventional pathway-type CRCs.