The mismatch repair gene hMSH2 is mutated in the prostate cancer cell line LNCaP.
OBJECTIVE
Mismatch repair genes are responsible for the coordinated correction of misincorporated nucleotides formed during DNA replication. Inactivating and inherited mutations in the prototypic mismatch repair gene hMSH2 have been described in a cancer predisposition syndrome known as hereditary nonpolyposis colon cancer. Patients with hereditary nonpolyposis colon cancer are at increased risk for colon cancer and extracolonic cancers such as upper tract transitional cell carcinoma but not prostate cancer. We investigated expression of hMSH2 in prostate cancer cell lines using genetic and molecular analysis.


METHODS
We used the 3 well described prostate cancer cell lines, DU145, LNCaP and PC3. Western blot analysis with monoclonal antibody to hMSH2 was used to assess expression. Southern blot and polymerase chain reaction of genomic DNA were used to identify genetic alterations in the hMSH2 gene. Single cell cloning, dinucleotide repeats and BAT-26 were used to assess the cell lines for microsatellite instability.


RESULTS
The prostate cancer cell line LNCaP did not express hMSH2 and was found to have a homozygous deletion of hMSH2 exons 9 to 16, resulting in truncation of the protein. While microsatellite analysis did not reveal alterations at the BAT-26 locus, single cell cloning produced several LNCaP subclones with alteration at 1 dinucleotide repeat.


CONCLUSIONS
The well described prostate cancer cell line LNCaP has a mutation in the hMSH2 gene, resulting in loss of expression and possible evidence of microsatellite instability. To our knowledge our finding is the first demonstration of a genetic alteration in hMSH2 in a prostate cancer cell line.
Leach
F S
FS
Department of Urology, The University of Texas Southwestern Medical Center, Dallas, Texas, USA.
Velasco
A
A
Hsieh
J T
JT
Sagalowsky
A I
AI
McConnell
J D
JD
D020137:Base Pair Mismatch / Q000235:genetics*; D015139:Blotting, Southern; D015153:Blotting, Western; D017931:DNA Primers; D004260:DNA Repair; D004268:DNA-Binding Proteins; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats; D051718:MutS Homolog 2 Protein; D009154:Mutation; D016133:Polymerase Chain Reaction; D011471:Prostatic Neoplasms / Q000235:genetics*; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D014407:Tumor Cells, Cultured
D017931:DNA Primers; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; C497172:MSH2 protein, human; D051718:MutS Homolog 2 Protein