[Functional mRNA expression analysis and classification of colonic biopsy samples using overall cDNA microarray technique].
BACKGROUND
Overall mRNA expression analysis of colon biopsies can contribute to the understanding of molecular background of the local alterations and gene ontology-based functional classification of colonic biopsies into inflammatory and neoplastic diseases.


METHODS
Total RNA was extracted from frozen biopsies and amplified by T7-method. Expression profile was evaluated by Atlas Glass 1K microarrays. After microarray quality control, applicable data were available from 10 adenomas, 6 colorectal adenocarcinoma (CRC), and inflammatory bowel diseases (IBDs: 3-3 CD and UC). Multivariate statistical and cell functional analyses were performed. Real-time RT-PCR and immunohistochemistry were used for validation.


RESULTS
Discriminant analysis of selected genes could correctly reclassify all 22 samples using 4 parameters (heat shock transcription factor-1, bystin-like, calgranulin-A, TRAIL receptor 3). IBD samples were characterized by overregulated chemokine (C-X-C motif) ligand 13, replication protein A1, E74-like factor 2 and downregulated TNF receptor-associated factor 6, BCL2-interacting killer genes. In adenomas upregulation of TNF receptor-associated factor 6, replication protein A1, E74-like factor 2 and underexpression of BCL2-associated X protein, calgranulin-A genes were found. CRC cases had significantly increased epidermal growth factor receptor, topoisomerase-1, v-jun, TNF receptor-associated factor 6 and TRAIL receptor 3, and decreased RAD51 and RAD52 DNA repair gene, protein phosphatase-2A and BCL2-interacting killer mRNA levels. Epidermal growth factor receptor RT-PCR and immunohistochemistry, topoisomerase-1 RT-PCR confirmed the chip results.


CONCLUSIONS
Different histological alterations can be objectively classified by functional, multivariate analysis using cDNA microarrays. Disease-specific gene expression patterns can assist to avoid the intermediate and nondescript cases in diagnostics, which do not belong to any of the conventional diagnostic groups.
Galamb
Orsolya
O
Semmelweis Egyetem, Altalános Orvostudományi Kar II. Belgyógyászati Klinika Budapest. orsg1@yahoo.com
Sipos
Ferenc
F
Dinya
Elek
E
Spisák
Sándor
S
Somorácz
Aron
A
Molnár
Béla
B
Tulassay
Zsolt
Z
D000230:Adenocarcinoma / Q000235:genetics / Q000473:pathology; D000236:Adenoma / Q000235:genetics / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000235:genetics; D001706:Biopsy; D015179:Colorectal Neoplasms / Q000737:chemistry / Q000235:genetics* / Q000473:pathology*; D016002:Discriminant Analysis; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D007150:Immunohistochemistry; D015212:Inflammatory Bowel Diseases / Q000235:genetics* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000032:analysis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation
D014408:Biomarkers, Tumor; D012333:RNA, Messenger