Characterization of somatostatin receptors and growth inhibition by the somatostatin analogue BIM23014 in small cell lung carcinoma xenograft: SCLC-6.
Human small cell lung cancer (SCLC) is a neuroendocrine tumour with a very poor prognostic. Receptors for somatostatin-14 and its synthetic analogue BIM23014 (Lanreotide) were characterized in 3 human SCLC xenografts (SCLC-6, SCLC-10 and SCLC-75) transplanted in nude mice. The binding activity of both iodinated ligands was tested by cross-linking assay. One major complex of 57kDa was identified by both ligands in all 3 tumours. Two other minor complexes were only detected by the natural ligand: 90kDa in all 3 tumours and 70kDa in 2 out of the 3 tumours (SCLC-6 and SCLC-75). Analysed by Northern hybridization, the expression of the gene encoding for the receptor subtype I was detected in all 3 tumours whereas the expression of the receptor subtype II was only detected in 2 out of the 3 tumours (SCLC-6 and SCLC-75). No receptor subtype III transcript was observed. The relative quantification of the detected messengers and of the cross-linked complexes determined by densitometry suggested that SCLC-6 contained a large amount of somatostatin receptors. SCLC-6 growing in nude mice was used to evaluate the antiproliferative effect of BIM23014. BIM23014 (250 micrograms, b.i.d. for 5 days) significantly inhibited tumor growth and had an additive effect with cis-platinum (1.5 mg/kg/day for 2 days) when given concomitantly. Values of the relative tumour volume as compared to control were: BIM23014 alone 57%, cis-platinum alone 57% and BIM23014 + cis-platinum: 78%. These experimental data suggest that BIM23014 given alone or in combination with cis-platinum could have a therapeutic potential in the treatment of somatostatin receptor positive SCLCs.
Prévost
G
G
IOCMH, BPBS, Bobigny, France.
Bourgeois
Y
Y
Mormont
C
C
Lerrant
Y
Y
Veber
N
N
Poupon
M F
MF
Thomas
F
F
D000595:Amino Acid Sequence; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D018288:Carcinoma, Small Cell / Q000188:drug therapy* / Q000473:pathology / Q000648:ultrastructure*; D002455:Cell Division / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000648:ultrastructure*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008969:Molecular Sequence Data; D009368:Neoplasm Transplantation; D010456:Peptides, Cyclic / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D017481:Receptors, Somatostatin / Q000032:analysis* / Q000235:genetics; D013004:Somatostatin / Q000031:analogs & derivatives*; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D010456:Peptides, Cyclic; D012333:RNA, Messenger; D017481:Receptors, Somatostatin; C060347:lanreotide; D013004:Somatostatin; D002945:Cisplatin