Inactivating mutations of proapoptotic Bad gene in human colon cancers.
Evidence exists that deregulation of apoptosis is involved in the mechanisms of cancer development, and the somatic mutations of apoptosis-related genes have been reported in human cancers. Bcl-XL/Bcl-2-associated death promoter (Bad), a proapoptotic member of Bcl-2 family, plays an important role in the intrinsic apoptosis pathway. To explore the possibility that the genetic alterations of Bad might be involved in the development of human cancers, we analyzed the entire coding region and all splice sites of human Bad gene in 47 colon adenocarcinomas. Overall, we detected two somatic missense mutations (4.3%) in Bad gene. Interestingly, both of the Bad mutations were detected in the gene sequences encoding the Bcl-2 homology3 domain of Bad, which has a crucial role in inducing cell death. Transfection study revealed that both of the tumor-derived Bad mutants had decreased apoptosis activities compared with the wild-type Bad, indicating that the Bad mutations reduced the cell death function of Bad. Co-immunoprecipitation assay revealed that binding of one of the tumor-derived Bad mutants with Bcl-2 and Bcl-XL is reduced. This is the first report on Bad gene mutation in human malignancies, and our data suggest that Bad gene is occasionally mutated in colon cancers and that somatic mutation of Bad may contribute to the development of colon cancers.
Lee
Jong Woo
JW
Department of Pathology, College of Medicine, The Catholic University of Korea, 505 Banpo-dong, Socho-gu, Seoul 137-701, Korea.
Soung
Young Hwa
YH
Kim
Su Young
SY
Nam
Suk Woo
SW
Kim
Chang Jae
CJ
Cho
Yong Gu
YG
Lee
Jong Heun
JH
Kim
Hong Sug
HS
Park
Won Sang
WS
Kim
Sang Ho
SH
Lee
Jung Young
JY
Yoo
Nam Jin
NJ
Lee
Sug Hyung
SH
D000483:Alleles; D017398:Alternative Splicing; D017209:Apoptosis; D002352:Carrier Proteins / Q000235:genetics*; D002460:Cell Line; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000235:genetics*; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D005091:Exons; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D020125:Mutation, Missense; D010957:Plasmids / Q000378:metabolism; D018807:Polymorphism, Single-Stranded Conformational; D011233:Precipitin Tests; D017434:Protein Structure, Tertiary; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D017422:Sequence Analysis, DNA; D014162:Transfection; D051025:bcl-Associated Death Protein; D051020:bcl-X Protein
C494819:BAD protein, human; C494811:BCL2L1 protein, human; D002352:Carrier Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051025:bcl-Associated Death Protein; D051020:bcl-X Protein