Expression of focal adhesion kinase and alpha5 and beta1 integrins in carcinomas and its clinical significance.
OBJECTIVE
To detect the expression pattern of FAK (focal adhesion kinase) and integrin alpha5 and beta1 subunits in different kinds of cancerous tissues and to study their correlation with clinicopathological data including tumor type, grade and lymph node status.


METHODS
Using an immunohistochemical technique, we examined the expression of FAK and integrin and subunits in cancerous and noncancerous tissues obtained from 75 patients with gastric carcinomas, 21 colorectal carcinomas, 16 hepatocellular carcinomas, 20 uterocervical carcinomas, and 20 breast carcinomas.


RESULTS
The staining of FAK was stronger in cancerous than in noncancerous areas. Enhanced expression of FAKwas detected in poor-differentiated carcinoma of the stomach and colorectum. Tumors with lymph node metastases had more FAK protein than those without metastases. In addition, the deeper the extent of tumor infiltration, the higher the FAK expression. The expression of integrin alpha5 and beta1 subunits was lower in cancerous areas than in noncancerous areas, but it was higher in well-differentiated cancerous tissues than in poor differentiated tissues. The relationship between the expression of integrin alpha5 and beta1 subunits and infiltration or metastasis was not significant. Cancerous tissues with stronger FAK expression (++ or +++) also had a higher expression of integrin alpha5 and beta1 subunits in the tumor and its unaffected margins.


CONCLUSIONS
FAK is a better marker for carcinogenesis and the progression of cancer than integrin alpha5 and beta1 subunit, and it may be not only a transformation-linked enzyme but also a progression-linked enzyme.
Su
Jian-Min
JM
Department of Biochemistry, FuDan University Medical Center, 138 Yixueyuan Road, Shanghai 200032, China.
Gui
Lu
L
Zhou
Yi-Ping
YP
Zha
Xi-Liang
XL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology; D015179:Colorectal Neoplasms / Q000378:metabolism / Q000473:pathology; D005260:Female; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D006801:Humans; D039482:Integrin alpha5; D019012:Integrin beta1 / Q000378:metabolism*; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000378:metabolism* / Q000473:pathology; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology; D014594:Uterine Neoplasms / Q000378:metabolism / Q000473:pathology
D015703:Antigens, CD; D039482:Integrin alpha5; D019012:Integrin beta1; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human