title: The expression of Bcl-2 family proteins differs between nonsmall cell lung carcinoma subtypes.
abstract: BACKGROUND
  Proteins of the Bcl-2 family play a key role in the control of apoptosis and carry out both proapoptotic and antiapoptotic functions. However, with the exception of Bcl-2 itself, little is known about the expression of these potentially critical proteins in nonsmall cell lung carcinoma.
  
  
  METHODS
  Immunohistochemistry was used to study the expression of Bcl-2 and 6 other Bcl-2 family proteins in a pilot series of 41 archival nonsmall cell lung carcinoma specimens (19 adenocarcinomas and 22 squamous cell carcinomas).
  
  
  RESULTS
  Overexpression of the apoptosis inhibitors Bcl-2 and Bcl-X(L) was observed in 10 of 41 samples (24%) and in 11 of 41 samples (27%), respectively. Loss of expression of proapoptotic proteins was observed as follows: Bak, 24 of 41 samples (59%); Bad, 21 of 41 samples (51%); Bid, 20 of 41 samples (49%); Bax, 14 of 41 samples (34%); and Bim/Bod, 2 of 41 samples (5%). Statistically significant differences in expression between adenocarcinoma samples and squamous cell carcinoma samples were observed for Bcl-X(L) (overexpression in 11 of 19 adenocarcinomas [58%] vs. 0 of 22 squamous cell carcinomas [0%]; P < 0.001) and for Bad (loss of expression in 5 of 19 adenocarcinomas [26%] vs. 16 of 22 squamous cell carcinomas [73%]; P = 0.004).
  
  
  CONCLUSIONS
  Although this was only a pilot study, the results revealed significant differences in the expression of apoptosis-related proteins both between individual samples of nonsmall cell lung carcinoma and between the two main histologic subtypes. Such differences may play a role in the development of lung tumors; and, if it is found that these differences are of clinical importance, then it may be required to regard nonsmall cell lung carcinoma subtypes as separate entities rather than as one disease.
authors.affiliation: Postgraduate Medical Institute of the University of Hull, Hull-York Medical School, University of Hull, Hull, United Kingdom.
authors.forename: Helen K
authors.initials: HK
authors.lastname: Berrieman
authors.forename: Laura
authors.initials: L
authors.lastname: Smith
authors.forename: Sara L
authors.initials: SL
authors.lastname: O'Kane
authors.forename: Anne
authors.initials: A
authors.lastname: Campbell
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lind
authors.forename: Lynn
authors.initials: L
authors.lastname: Cawkwell
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism*; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000378:metabolism*; D010865:Pilot Projects; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2