Expression of alpha6 integrin subunit is associated with malignancy in gastric gastrointestinal stromal tumors.
BACKGROUND
Gastrointestinal stromal tumors (GISTs) are the most common non-epithelial neoplasms of the gastrointestinal tract. The aim of this study was to investigate the clinicopathological and immunohistochemical features of gastric GISTs and to evaluate the degree of integrin expression in order to determine the need for surgery or predict the prognosis for GIST patients.


METHODS
Clinicopathological findings were obtained from patients' records. Specimens from 32 cases of gastric GIST were analyzed with immunohistochemical methods. The c-kit negative examples among the original 48 patients with gastric submucosal and muscle layer tumors were excluded from the study.


RESULTS
There was a significant correlation between p53 protein expression and tumor malignancy. The positive staining for proliferating cell nuclear antigen was observed in all patients, and the mean tumor proliferation index for benign and malignant groups were 3.0% and 16.3%, respectively. alpha5beta1 integrin and alpha6 integrin subunit were expressed from moderately to strongly in tumor cells, and alpha 6 integrin subunit expression correlated significantly with whether tumors were classified as benign or malignant. However, there were no significant differences between the survival of GIST patients and integrin expression, mitotic rate, tumor size, or tumor malignancy.


CONCLUSIONS
Malignant GISTs show significant expression of alpha6 integrin subunit. It may be useful in supporting other parameters, such as p53, MI, and tumor size. We suggest that alpha6 integrin subunit expression may be useful as an indication for surgery and also as one of several prognostic factors.
Takeyama
Hiromitsu
H
Department of Gastroenterological Surgery, Nagoya City University Graduate School of Medical Sciences, Nagoya 4678601, Japan. takeyama@med.nagoya-cu.ac.jp
Funahashi
Hitoshi
H
Sawai
Hirozumi
H
Takahashi
Hiroki
H
Yamamotorm
Minoru
M
Akamo
Yoshimi
Y
Manabe
Tadao
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D006801:Humans; D007150:Immunohistochemistry; D039503:Integrin alpha6 / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D039503:Integrin alpha6; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53