A gene marker panel covering the Wnt and the Ras-Raf-MEK-MAPK signalling pathways allows to detect gene mutations in 80% of early (UICC I) colon cancer stages in humans.
BACKGROUND
Very recently a gene marker panel that allows the mutational analysis of APC, CTNNB1, B-RAF and K-RAS was conceived. The aim of the present study was to use the 4-gene marker panel covering the Wnt and Ras-Raf-MEK-MAPK signalling pathways to determine the percentage of sporadic colorectal carcinomas (CRC) carrying at least one of the four above-mentioned genes in a mutated form alone and/or in combination with microsatellite instability (MSI) and to compare the sensitivity of the gene marker panel used in this study with that of gene marker panels previously reported in the scientific literature.


METHODS
CTNNB1 and B-RAF were screened by PCR-single-strand conformation polymorphism analysis and K-RAS gene mutations by restriction fragment length polymorphism analysis. For the mutational analysis of the APC gene mutation cluster region (codons 1243-1567) direct DNA sequencing was performed. The U.S. National Cancer Institute microsatellite panel (BAT25, BAT26, D2S123, D5S346 and D17S250) was used for MSI analysis.


RESULTS
It could be shown that about 80% of early stage CRC (UICC stages I and II) and over 90% of CRC in the UICC stage IV carried at least one mutated gene and/or showed MSI. No significant increase in the gene mutation frequencies could be determined when comparing tumours in the UICC stage I with those in UICC stage IV.


CONCLUSIONS
When compared with previously published gene marker panels the 4-gene marker panel used in the present study shows an excellent performance, allowing to detect genetic alterations in 80-90% of human sporadic CRC samples analyzed.
Scholtka
Bettina
B
Institute of Nutritional Science, University of Potsdam, Nuthetal, Germany.
Schneider
Mandy
M
Melcher
Ralph
R
Katzenberger
Tiemo
T
Friedrich
Daniela
D
Berghof-Jäger
Kornelia
K
Scheppach
Wolfgang
W
Steinberg
Pablo
P
D025601:Adenomatous Polyposis Coli Protein / Q000235:genetics; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D005260:Female; D006801:Humans; D048369:MAP Kinase Kinase 1 / Q000235:genetics*; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D008875:Middle Aged; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D011518:Proto-Oncogene Proteins / Q000235:genetics; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras); D012680:Sensitivity and Specificity; D015398:Signal Transduction; D051153:Wnt Proteins / Q000235:genetics*; D051176:beta Catenin / Q000235:genetics; D048490:raf Kinases / Q000235:genetics*; D018631:ras Proteins / Q000235:genetics*
D025601:Adenomatous Polyposis Coli Protein; D014408:Biomarkers, Tumor; C495270:CTNNB1 protein, human; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; D051153:Wnt Proteins; D051176:beta Catenin; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf; D048490:raf Kinases; D048369:MAP Kinase Kinase 1; C482125:MAP2K1 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins