Expression of c-Met correlates with grade of malignancy in human astrocytic tumours: an immunohistochemical study.
OBJECTIVE
Recent studies suggest the involvement of hepatocyte growth factor/scatter factor (HGF/SF) in glioma cell invasion and tumour progression. We investigated the distribution and rate of tumour cells that express c-Met protein, which is the cell-surface receptor for HGF/SF, in astrocytic tumours. The type of cells that express c-Met in tumour tissues was also identified.


RESULTS
c-Met expression was screened immunohistochemically in a total of 43 astrocytic tumours, including 14 low-grade astrocytomas (A), 13 anaplastic astrocytomas (AA) and 16 glioblastoma multiforme (GBM), c-Met reactivity was demonstrated predominantly in the cytoplasm of tumour cells. Bizarre large tumour cells tended to stain intensely. Higher c-Met expression levels (> or = 2+, more than 25% cells were positive) were noted in 21.4% of (A) vs. 53.8% in (AA) and 87.5% in (GBM) (P < 0.001), indicating a clear relationship between c-Met protein staining and higher grade astrocytic tumours. Moreover, c-Met immunoreactivity was also shown in tumour microvasculature, reactive astrocytes, and neurones in the cortex infiltrated by glioma cells. In 85.7% of cases containing infiltrated cortex, neurones were positive vs. no neurones in non-neoplastic regions (P < 0.002).


CONCLUSIONS
This evidence suggests that c-Met expression in the brain could be associated with astrocytoma progression and also reactive process. Immunohistochemical determination of c-Met-expressing cell types helps to understand possible roles of c-Met in tumour tissues.
Nabeshima
K
K
Second Department of Pathology, Miyazaki Medical College, Japan.
Shimao
Y
Y
Sato
S
S
Kataoka
H
H
Moriyama
T
T
Kawano
H
H
Wakisaka
S
S
Koono
M
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D001253:Astrocytes / Q000378:metabolism / Q000473:pathology; D001254:Astrocytoma / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D001932:Brain Neoplasms / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D002540:Cerebral Cortex / Q000378:metabolism / Q000473:pathology; D002648:Child; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008833:Microcirculation / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D009367:Neoplasm Staging; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D019859:Proto-Oncogene Proteins c-met / Q000096:biosynthesis*
D019859:Proto-Oncogene Proteins c-met