Somatostatin analogue RC-160 and LH-RH antagonist SB-75 inhibit growth of mia PaCa-2 human pancreatic cancer xenografts in nude mice

Sinisa Radulovic, Ana Maria Comaru-Schally, Slobodan Milovanovic, Andrew V. Schally

Research output: Contribution to journalArticlepeer-review

34 Scopus citations

Abstract

Nude mice bearing xenografts of the MIA PaCa-2 human pancreatic cancer cell line were treated with sustained-release formulations (microcapsules) of luteinizing hormone releasing hormone (LH-RH) agonist [D-Trp6]-LH-RH, somatostatin analogue RC-160 (D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2), or combination of both analogues. Other groups of mice received daily subcutaneous injections of LH-RH antagonist SB-75 [Ac-D-Nal(2)1,D- Phe(4Cl)2,D-Pal(3)3,D-Cit6,D-Ala10-LH-RH] or bombesin antagonist RC- 3095. At necropsy, in mice given microcapsules releasing 25 μg/day of [D- Trp6]-LH-RH, tumor weight and volume were decreased, but not significantly, as compared with control mice. Microcapsules of RC-160, releasing 25 μg/day, significantly reduced tumor volume, percentage change in tumor volume, and tumor weight. Combination of RC-160 and [D-Trp6]-LH-RH inhibited tumor growth to a somewhat greater extent than RC-160 alone. Bombesin antagonist RC-3095, at a dose of 25 μg/day, did not influence the growth of tumors. In mice receiving 100 μg/day of antagonist SB-75, there was a significant decrease in tumor weight and volume and a significant reduction in the weight of ovaries and uteri. Specific binding of [125I]RC-160 and [125I][D- Trp6]-LH-RH, but not [125I]Tyr4-bombesin, was found on MIA PaCa-2 cells in culture. [D-Trp6]-LH-RH, SB-75, and RC-160 inhibited the growth of MIA PaCa-2 cells in vitro. Neither bombesin nor RC-3095 influenced the growth of MIA PaCa-2 cells in cultures. The results indicate that the LH-RH antagonist SB-75 could be tried for treatment of pancreatic cancer. Our findings confirm the efficacy of somatostatin analogue RC-160 in inhibiting the growth of pancreatic cancers and suggest that the combination of RC-160 and agonist [D- Trp6]-LH-RH might possibly increase the therapeutic response.

Original languageEnglish (US)
Pages (from-to)88-97
Number of pages10
JournalPancreas
Volume8
Issue number1
DOIs
StatePublished - Jan 1993
Externally publishedYes

Keywords

  • Bombesin
  • Luteinizing hormone releasing hormone agonist and antagonist
  • Nude mice
  • Pancreatic cancer
  • Somatostatin

ASJC Scopus subject areas

  • Gastroenterology
  • Endocrinology

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