p53, BCL-2 and BAX in non-small cell lung cancer brain metastases: a comparison of real-time RT-PCR, ELISA and immunohistochemical techniques.
OBJECTIVE
Metastasis to the brain is a severe and common complication in non-small cell lung cancer (NSCLC). The examination of cell cycle associated genes in these lesions may contribute to the understanding of metastatic growths in the central nervous system. The aim of this study was to evaluate the p53, BCL-2 and BAX mRNA and protein expression in NSCLC brain metastases in comparison with matched primary tumors.


METHODS
For quantitative TaqMan real-time reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), fresh frozen tumor specimens from 12 patients with NSCLC brain metastases were available. For immunohistochemical staining, 78 surgically removed NSCLC brain metastases were used. PCR results were analysed using the DeltaDeltaCT method. Staining was analysed using a modified immunoreactive score (IRS).


RESULTS
Overall, p53, BCL-2 and BAX expression values in brain metastases and primary tumors showed a wide variety. The comparison of different techniques revealed different findings on the mRNA and protein level. Herein, PCR and ELISA revealed no clear tendencies. In contrast, immunohistochemistry showed significant overexpression of BAX and underexpression of BCL-2 in brain metastases.


CONCLUSIONS
A high variability in the expression of p53, BCL-2 and BAX in NSCLC exists in brain metastases. Immunohistochemistry revealed overexpression of BAX and underexpression of BCL-2 in brain metastases, whereas there were no clear tendencies using PCR and ELISA techniques. More insights into the BAX/BCL-2 interaction are needed before reasonable conclusions can be drawn from the existing data.
Stark
Andreas M
AM
Department of Neurosurgery, University of Schleswig-Holstein Medical Center, Campus Kiel, Schittenhelmstr. 10, 24105 Kiel, Germany. starka@nch.uni-kiel.de
Hugo
Heinz-Herrmann
HH
Tscheslog
Hauke
H
Mehdorn
H Maximilian
HM
D001932:Brain Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000556:secondary*; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008175:Lung Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis* / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D018709:Statistics, Nonparametric; D016159:Tumor Suppressor Protein p53 / Q000032:analysis* / Q000235:genetics; D051028:bcl-2-Associated X Protein / Q000032:analysis* / Q000235:genetics
D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D016159:Tumor Suppressor Protein p53; D051028:bcl-2-Associated X Protein