TITLE:
No Association between p53 Immunohistochemical Staining and RASSF1 or DAPK1 Hypermethylation in Non-Small Cell Lung Cancer
AUTHORS:
Danny V. Colombara, David Eidsmoe, Joshua E. Stern, Qinghua Feng, Hubert Vesselle, Stephen E. Hawes
KEYWORDS:
NSCLC, p53, Hypermethylation, RASSF1, DAPK1
JOURNAL NAME:
Journal of Cancer Therapy,
Vol.6 No.8,
July
28,
2015
ABSTRACT: p53 mutations have been linked with shortened survival rates in non-small
cell lung cancer (NSCLC). Hypermethylation of RASSF1 and DAPK1 genes, which are
downstream targets of p53, has also been linked to a poor prognosis in lung
cancer patients. We investigated whether p53 mutations, assessed as p53
stabilization by immunohistochemistry (IHC), were independent of DAPK1 and
RASSF1 promoter hypermethylation. We examined 103 resected NSCLC tumors for
which we had p53 IHC and RASSF1 and DAPK1 methylation data. p53 protein
expression was determined by IHC and graded using a semi-quantitative scoring
method. DAPK1 and RASSF1 methylations were determined on tumor blocks by
MethyLight real-time PCR assays represented as the percent of methylated
reference DNA (PMR). Our primary results found no evidence for an association
between the p53 IHC score and RASSF1 and DAPK1 PMR values, P = 0.46 and P = 0.68,
respectively.