Affiliations: 2nd Department of Medicine, Semmelweis University,
Budapest, Hungary | Molecular Medicine Research Unit, Hungarian Academy of
Sciences, Budapest, Hungary | Transplantation and Surgical Department, Semmelweis
University, Budapest, Hungary | Department of Nutrition, National Institute of Food
and Nutritional Science, Budapest, Hungary
Note: [] Corresponding author: Sándor Spisák, 2nd Department of
Medicine Semmelweis University, Szentkirályi str. 46, 1088 Budapest,
Hungary. Tel.: +36 1 266 09 26; Fax: +36 1 266 08 16; E-mail: spisak@abc.hu
Abstract: The exact molecular background and the connection between protein
and mRNA expression in colorectal cancer (CRC) development and progression are
not completely elucidated. Our purposes were the identification of protein
markers of colorectal carcinogenesis and progression using protein arrays and
validation on tissue microarrays. The connection between antibody and mRNA
expression array results was also examined. Using cancerous and adjacent normal
samples from 10 patients with early and 6 with advanced CRC, 67 differentially
expressed genes were identified between normal and cancerous samples. A marker
set containing 6 proteins (CCNA1, AR, TOP1, TGFB, HSP60, ERK1) was developed
which could differentiate normal specimen, early and late stage CRC with high
sensitivity and specificity. Dukes D stage samples were analyzed on
HGU133plus2.0 microarrays. In these samples, mRNA and protein expression of 143
genes showed strong positive correlations (R^{2} >0.8),
while a negative correlation (R^{2} > 0.9) was found in case
of 95 genes. Based on our results a correlation could be established between
transcriptome and antibody array results, hence the former may be used as a
high-capacity screening method before applying antibody arrays containing
already planned targets. Antibody microarrays may have a fundamental importance
in testing of marker combinations and future application in diagnostics of tumorous diseases.
