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Expression of Bax, a pro‐apoptotic member of the Bcl‐2 family, in esophageal squamous cell carcinoma
Author(s) -
Sarbia Mario,
Bittinger Fernando,
Grabellus Florian,
Verreet Patrick,
Dutkowski Philipp,
Willers Rainhart,
Gabbert Helmut E.
Publication year - 1997
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/(sici)1097-0215(19971114)73:4<508::aid-ijc9>3.0.co;2-3
Subject(s) - apoptosis , cancer research , basal cell , bcl 2 family , carcinoma , esophageal squamous cell carcinoma , oncology , medicine , pathology , biology , programmed cell death , genetics
Samples of normal esophageal squamous epithelium (n = 10), severe squamous cell dyplasia (n = 22), carcinoma in situ (n = 15), invasive squamous cell carcinoma (n = 172), lymph‐node metastasis (n = 21) and 2 permanent esophageal squamous cell carcinoma cell lines were analyzed immunohistochemically for Bax expression using a polyclonal anti‐Bax antibody. Immunostaining was evaluated according to a score system (0–8 points) based on the percentage of positive tumor cells and the relative immunostaining intensity. Cytoplasmatic staining for Bax protein was found uniformly in all cell layers of the normal esophageal squamous epithelium. In contrast, a gradual loss of immunoreactivity for Bax was found in a fraction of pre‐neoplastic and neoplastic lesions. Upon comparison of the amount of Bax expression between the different types of lesion, however, no significant differences were found between severe squamous cell dysplasias, carcinomas in situ, invasive carcinomas and lymph‐node metastases. In both esophageal carcinoma cell lines, immunoreactivity for Bax was found and confirmed by means of Northern blot analysis. In invasive carcinomas, Bax immunoreactivity was inversely correlated with Bcl‐2 expression ( p = 0.0243) and decreased continuously with decreasing tumor differentiation ( p = 0.0011). No correlation was found between Bax expression and the following parameters: depth of invasion, nodal status and tumor size. Bax expression had no influence on the post‐operative survival of esophageal cancer patients. Int. J. Cancer 73:508–513, 1997. © 1997 Wiley‐Liss, Inc.