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Increased hMSH2 protein expression in
glioblastoma multiforme
Srivastava T, Chattopadhyay P, Mahapatra AK, Sarkar C, Sinha S
Department of Biochemistry, All India Institute of Medical
Sciences, New Delhi, India.
hMSH2 and hMLH1 are the most commonly studied mismatch repair proteins and their
absence is associated with microsatellite instability (MSI) especially in
hereditary non-polyposis colorectal cancer, and also in some sporadic
tumors.
However, there are some tumors, namely, urothelial neoplasms and salivary gland
tumors, where overexpression of the proteins has been reported, though the
implications of these findings are not very clear.
There is no report on the expression of these proteins in different grades of
human astrocytic tumors.
We have studied the expression pattern of hMSH2 and hMLHI in high (Grade IV,
glioblastoma multiforme (GBM)) and low (Grade II, astrocytoma (AS)) grade
primary human gliomas by immunohistochemistry.
We observed that there was a significantly higher expression of hMSH2 protein in
28 GBM (mean 703.07 +/- 236.28) as compared with 27 AS (mean 307.03 +/- 204.71),
p = 1.47 x 10(-8) by a two-tailed t-test of unpaired samples.
However, for hMLH1 no such difference was observed, mean counts being 543.29 +/-
320.35 for 27 GBM and 505.92 +/- 342.37 for 26 AS, p = 0.67.
A small proportion of tumors was observed to be immunonegative for either of the
proteins in both high- and low-grade tumors.
While MSI has been shown previously to be infrequent in human astrocytic tumors,
the implications of the overexpression of hMSH2 in GBM are not clear.
PMID: 15015769 [PubMed - indexed for MEDLINE]
Source: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15015769
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