title: Bcl-2 expression correlates with apoptosis induction but not loss of clonogenic survival in small cell lung cancer cell lines treated with etoposide.
abstract: The influence of bcl-2 oncogene expression on etoposide-induced apoptosis and clonogenic survival was investigated in five small cell lung cancer (SCLC) cell lines, three of which were bcl-2-expressing and two of which were non-bcl-2-expressing. The bcl-2-expressing lines displayed a lower apoptosis propensity than the non-bcl-2-expressing lines. When bcl-2-expressing cells were incubated in cystine/ methionine-free (CMF) medium, etoposide-induced apoptosis was restored to levels comparable to those seen in non-bcl-2-expressing lines. However, the endpoint of clonogenic survival after drug treatment did not display any consistent pattern that correlated with bcl-2 status. In addition, treatment of the two bcl-2-expressing cell lines with etoposide in CMF medium did not modify their clonogenic survival curves compared to treatment in regular medium. These results are consistent with the idea that bcl-2 expression modulates etoposide-induced apoptosis but not clonogenic survival.
authors.affiliation: Department of Experimental Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston 77030, USA.
authors.forename: C
authors.initials: C
authors.lastname: Breton
authors.forename: M D
authors.initials: MD
authors.lastname: Story
authors.forename: R E
authors.initials: RE
authors.lastname: Meyn
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D018288:Carcinoma, Small Cell / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology*; D002470:Cell Survival / Q000187:drug effects; D003470:Culture Media; D003553:Cystine / Q000378:metabolism / Q000494:pharmacology; D005047:Etoposide / Q000494:pharmacology*; D015870:Gene Expression; D019254:Genes, bcl-2; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology*; D008715:Methionine / Q000378:metabolism / Q000494:pharmacology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*; D014407:Tumor Cells, Cultured
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D003470:Culture Media; D019253:Proto-Oncogene Proteins c-bcl-2; D003553:Cystine; D005047:Etoposide; D008715:Methionine