Expression of p16 and lack of pRB in primary small cell lung cancer.
The retinoblastoma protein (pRB), p16, and cyclin D1 are major components of the RB pathway, which controls the G1 checkpoint of the cell cycle. Proper regulation of this pathway is crucial for normal cell proliferation. Abnormal forms of these proteins have been found in various types of malignant tumours. In the present report, immunohistochemical techniques were applied to study the expression of pRB, p16, and cyclin D1 in 161 samples of primary small cell lung cancer (SCLC) and 20 samples of non-small cell lung cancer (NSCLC). While pRB and cyclin D1 staining was negative in 161 specimens of SCLC, expression of p16 was observed in 153 samples. In contrast to SCLC, 16 out of 20 NSCLC cases exhibited pRB expression and 15 showed cyclin D1 expression, but only very weak p16 staining was found in five samples. These observations could provide additional criteria for the distinction between SCLC and NSCLC. Furthermore, these findings, based on primary tissues, implicate different mechanisms in the tumourigenesis of SCLC and NSCLC.
Yuan
J
J
Department of Obstetrics and Gynecology, School of Medicine, J. W. Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.
Knorr
J
J
Altmannsberger
M
M
Goeckenjan
G
G
Ahr
A
A
Scharl
A
A
Strebhardt
K
K
D000230:Adenocarcinoma / Q000175:diagnosis / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis / Q000378:metabolism; D018288:Carcinoma, Small Cell / Q000175:diagnosis / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000378:metabolism; D019938:Cyclin D1 / Q000378:metabolism; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques; D008175:Lung Neoplasms / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D016160:Retinoblastoma Protein / Q000378:metabolism*
D019941:Cyclin-Dependent Kinase Inhibitor p16; D009363:Neoplasm Proteins; D016160:Retinoblastoma Protein; D019938:Cyclin D1