208P - Ezh2 expression in colorectal (CRC) cancer: single nucleotide polymorphism (SNP) characterization and correlation with clinico-pathological and mole...

Date 30 September 2012
Event ESMO Congress 2012
Session Poster presentation II
Topics Colon Cancer
Rectal Cancer
Translational Research
Presenter Lorenzo Fornaro
Authors L. Fornaro1, F. Crea2, P. Faviana3, G. Masi4, C. Vivaldi1, V. De Gregorio1, E. Paolicchi2, G. Fontanini3, R. Danesi2, A. Falcone5
  • 1U.o. Oncologia Medica 2 Universitaria, Azienda Ospedaliero-Universitaria Pisana, 56126 - Pisa/IT
  • 2Dept Of Internal Medicine, Dept of Oncology, Transplants and New Technologies, 56010 - Pisa/IT
  • 3Pathology, Azienda Ospedaliero-Universitaria Pisana, Pisa/IT
  • 4Oncologia Medica Universitaria, Azienda Ospedaliero-Universitaria Pisana, 56126 - Pisa/IT
  • 5Dept. Of Oncology-presidio Ospedaliero, Azienda Ospedaliero-Universitaria Pisana, 56126 - Pisa/IT

Abstract

Background

EZH2 is an epigenetic factor, essential for stem cell self-renewal. EZH2 rs3757441 SNP is associated with outcome in metastatic CRC patients treated with FOLFIRI + /-bevacizumab.

Material and methods

We are investigating the correlation between EZH2 expression and other clinico-pathological and molecular parameters in 129 primary CRC samples. EZH2 expression was evaluated by immunohistochemistry, KRAS codon 12-13 and BRAF V600E mutations were screened by pyrosequencing analysis, and EZH2 SNP variants were identified by real-time PCR. Studied parameters were correlated with the percentage of EZH2-positive cells by T test and ANOVA.

Results

Characteristics of the specimens so far evaluated are: stage I/II/III/IV, 5/47/54/23; grading 1/2/3, 0/81/48; right colon/left colon/rectum, 56/49/24; mucinous histology, 40; KRAS wt/mut, 74/55; BRAF wt/mut, 115/14; rs3757441 genotype CC/CT/TT, 5/36/59. The percentage of EZH2-positive cells does not correlate with tumor stage and grading, nor with KRAS and BRAF status. There is a trend toward higher EZH2 expression with rs3757441-CC genotype (p = 0.1). The percentage of EZH2-positive cells is significantly higher in mucinous than in non-mucinous tumors (p = 0.022).

Conclusions

CRC tumors with mucinous features show higher EZH2 expression, which may represent one of the mechanisms behind a more aggressive tumor behavior. EZH2 could therefore represent a putative prognostic indicator and a candidate therapeutic target in CRC.

Disclosure

All authors have declared no conflicts of interest.