Mismatch repair, p53 and beta-catenin proteins in colorectal cancer.
BACKGROUND
Mismatch repair (MMR) proteins (MSH2 and MLH1) deficiency is responsible for microsatellite instability (MSI) status. We evaluated p53 and beta-catenin expressions in colorectal cancer specimens with known microsatellite status, previously assessed by means of the polymerase chain reaction (PCR). We also analyzed the MMR proteins immunostaining and compared the results with those ascertained by PCR.


METHODS
Twenty-five colorectal cancer patients were analyzed for immunohistochemical expression of p53, beta-catenin, MSH2 and MLH1 proteins.


RESULTS
The microsatellite status was only significantly correlated with p53 expression and MRR proteins pattern.


CONCLUSIONS
We demonstrated a significantly higher p53 expression in MSI colorectal specimens. The concordance rate between immunohistochemistry and PCR was so high (80%) that the immunohistochemical technique can be proposed as a method to select MSI patients for improved outcome and response to chemotherapy.
Valentini
Anna Maria
AM
Department of Pathology, IRCCS S De Bellis, Castellana Grotte (BA), Italy.
Renna
Letizia
L
Armentano
Raffele
R
Pirrelli
Michele
M
Di Leo
Alfredo
A
Gentile
Mattia
M
Caruso
Maria Lucia
ML
D048868:Adaptor Proteins, Signal Transducing; D020137:Base Pair Mismatch; D015820:Cadherins / Q000235:genetics; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000473:pathology; D002352:Carrier Proteins; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology; D003598:Cytoskeletal Proteins / Q000235:genetics*; D004260:DNA Repair; D004268:DNA-Binding Proteins; D006801:Humans; D007150:Immunohistochemistry; D018895:Microsatellite Repeats; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein; D009363:Neoplasm Proteins / Q000235:genetics; D009687:Nuclear Proteins; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins / Q000235:genetics; D015534:Trans-Activators / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*; D051176:beta Catenin
D048868:Adaptor Proteins, Signal Transducing; C495270:CTNNB1 protein, human; D015820:Cadherins; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; C501486:MLH1 protein, human; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D015534:Trans-Activators; D016159:Tumor Suppressor Protein p53; D051176:beta Catenin; C497172:MSH2 protein, human; D000070957:MutL Protein Homolog 1; D051718:MutS Homolog 2 Protein