High bad and bcl-xL gene expression and combined bad, bcl-xL, bax and bcl-2 mRNA levels: molecular predictors for survival of stage 2 soft tissue sarcoma patients.
The role of the bcl-2 gene family members in promoting or antagonizing apoptosis in malignant tumors, including soft tissue sarcomas (STS), is well known. However, the impact of mRNA expression of bcl-2 family genes on prognosis has not been thoroughly investigated in STS. Samples from 82 STS patients were analyzed for mRNA expression of bad, bax, bcl-xL and bcl-2 by a high-throughput quantitative RT-PCR approach, using validated assays based on TaqMan technology. The mRNA data, related to glyceraldehyde-3-phosphate dehydrogenase expression measured in the same sample, were analysed for their correlation to tumor stage and overall survival of patients. In a Kaplan-Meier analysis none of the mRNA levels investigated differed significantly with regard to their impact on survival (log-rank test). However, after including the tumor stage in the statistical analysis, a borderline significance was observed for bad mRNA expression (p=0.068) indicating a stage-specific impact of mRNA expression on prognosis. Considering STS patients of tumor stage 2, multivariate Cox analysis revealed that bad mRNA values > or = 10 (p=0.0039; RR=9.08), bcl-xL > or = 1.5 (p=0.067; RR=4.59), bax > or = 0.005 (p=0.1; RR=2.84) and bcl-2 < 3 (p=0.42; RR=1.7) were associated with a poor prognosis. Combined high bad/bcl-xL mRNA expression levels revealed a 20-fold increase in the relative risk of tumor-related death (p=0.016) when comparing the poor and good prognosis groups. There was a 14.5-fold and 6.5-fold increase in the risk for the combinations of high bax/bcl-xL mRNA (p=0.018) and bax/bcl-2 mRNA expression (p=0.017), respectively. In conclusion, high bad mRNA levels and combined values of bad/bcl-xL bax/bcl-xL and bax/bcl-2 appear to be independent prognostic factors at least for stage 2 STS patients. In the combinations of mRNA levels there was more than an additive effect pointing to different pathways of prognostic relevance.
Köhler
Thomas
T
Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, University of Leipzig, Germany.
Würl
Peter
P
Meye
Axel
A
Lautenschläger
Christine
C
Bartel
Frank
F
Borchert
Silke
S
Bache
Matthias
M
Schmidt
Hannelore
H
Holzhausen
Hans-Jürgen
HJ
Taubert
Helge
H
D000328:Adult; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D009367:Neoplasm Staging; D011379:Prognosis; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis / Q000235:genetics; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012509:Sarcoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D012983:Soft Tissue Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D051028:bcl-2-Associated X Protein; D051025:bcl-Associated Death Protein; D051020:bcl-X Protein
C494819:BAD protein, human; C494826:BAX protein, human; C494811:BCL2L1 protein, human; D002352:Carrier Proteins; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D051028:bcl-2-Associated X Protein; D051025:bcl-Associated Death Protein; D051020:bcl-X Protein