An immunohistochemical study of p16, pRb, p21 and p53 proteins in human esophageal cancers
Kato, H.; Yoshikawa, M.; Fukai, Y.; Tajima, K.; Masuda, N.; Tsukada, K.; Kuwano, H.; Nakajima, T.
Anticancer Research 20(1a): 345-349
2000
ISSN/ISBN: 0250-7005 PMID: 10769678 Document Number: 519075
Background: Cell cycle-associated proteins, p16, pRb, p21 and p53 are important in regulating the G1-S checkpoint in the cell cycle, and their functional alterations play key roles in carcinogenesis and cell proliferation. Materials and Methods: We immunohistochemically examined the expression of p16, pRb, p21 and p53 proteins by using surgically resected tissues from 35 patients with primary esophageal cancers. Results: In 35 esophageal cancers, the expressions of p16, pRb, p21 and p53 proteins were detectable in 4(11.4%), 25(71.4%), 11(31.4%) and 20(57.1%) respectively. Interestingly, 24 of 25 pRb positive cancers (96.0%) had negative p16, whereas three of ten pRb-negative cancers (30.0%) had high levels of p16 (p<0.05). In 11 cases of p21 positive immunostaining, there was lymph node metastasis (pN1) in 9 (81.8%). Conclusions: These results suggest that abnormalities of p16 protein may be closely associated with the carcinogenesis or cell proliferation of esophageal cancers.