title: Identification of semaphorin E as a non-MDR drug resistance gene of human cancers.
abstract: To improve cancer chemotherapy, a better understanding of the molecular mechanisms of drug resistance is essential. To identify the molecules responsible for drug resistance that is unrelated to MDR1 or MRP gene products, a eukaryotic expression cDNA library of cis-diamminedichloroplatinum(II) (CDDP)-resistant ovarian cancer TYKnuR cells was introduced into Cos-7 cells. After repeated CDDP selection, cDNA homologous to murine semaphorin E was isolated from surviving cells. Human semaphorin E (H-sema E) was overexpressed in CDDP-resistant cell lines and was readily induced not only by diverse chemotherapeutic drugs but also by x-ray and UV irradiation. Transfection of H-sema E conferred a drug-resistant phenotype to CDDP-sensitive cells. In addition, the aberrant expression of H-sema E protein was detected immunohistochemically in 14 of 42 (33.3%) recurrent squamous cell carcinomas removed at autopsy after extensive radiochemotherapy. Recently, another member of the semaphorin family, CD100, was shown to significantly improve the viability of B lymphocytes. These results suggest the involvement of semaphorins in diverse cell survival mechanisms.
authors.affiliation: Pathology Division, National Cancer Center Research Institute, 1-1 Tsukiji 5-chome, Chuo-ku, Tokyo 104, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamada
authors.forename: R
authors.initials: R
authors.lastname: Endo
authors.forename: M
authors.initials: M
authors.lastname: Gotoh
authors.forename: S
authors.initials: S
authors.lastname: Hirohashi
mesh_terms: D000328:Adult; D000595:Amino Acid Sequence; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology / Q000627:therapeutic use; D002352:Carrier Proteins / Q000235:genetics*; D002945:Cisplatin / Q000494:pharmacology / Q000627:therapeutic use; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics*; D010051:Ovarian Neoplasms / Q000188:drug therapy / Q000235:genetics*; D040121:Semaphorin-3A; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D002352:Carrier Proteins; D018076:DNA, Complementary; D009419:Nerve Tissue Proteins; C108639:SEMA3A protein, human; C488217:Sema3a protein, mouse; D040121:Semaphorin-3A; D002945:Cisplatin