Antagonistic analogs of growth hormone-releasing hormone increase the efficacy of treatment of triple negative breast cancer in nude mice with doxorubicin; A preclinical study

Roberto Perez, Andrew V. Schally, Petra Popovics, Renzhi Cai, Wei Sha, Ricardo Rincon, Ferenc G. Rick

Research output: Contribution to journalArticle

11 Scopus citations


Introduction: This study evaluated the effects of an antagonistic analog of growth hormone-releasing hormone, MIA-602, on tumor growth, response to doxorubicin, expression of drug resistance genes, and efflux pump function in human triple negative breast cancers. Methods: HCC1806 (doxorubicin-sensitive) and MX-1 (doxorubicin-resistant), cell lines were xenografted into nude mice and treated with MIA-602, doxorubicin, or their combination. Tumors were evaluated for changes in volume and the expression of the drug resistance genes MDR1 and NANOG. In-vitro cell culture assays were used to analyze the effect of MIA-602 on efflux pump function. Results: Therapy with MIA-602 significantly reduced tumor growth and enhanced the efficacy of doxorubicin in both cell lines. Control HCC1806 tumors grew by 435%, while the volume of tumors treated with MIA-602 enlarged by 172.2% and with doxorubicin by 201.6%. Treatment with the combination of MIA-602 and doxorubicin resulted in an increase in volume of only 76.2%. Control MX-1 tumors grew by 907%, while tumors treated with MIA-602 enlarged by 434.8% and with doxorubicin by 815%. The combination of MIA-602 and doxorubicin reduced the increase in tumor volume to 256%. Treatment with MIA-602 lowered the level of growth hormonereleasing hormone and growth hormone-releasing hormone receptors and significantly reduced the expression of multidrug resistance (MDR1) gene and the drug resistance regulator NANOG. MIA-602 also suppressed efflux pump function in both cell lines. Conclusions: We conclude that treatment of triple negative breast cancers with growth hormone-releasing hormone antagonists reduces tumor growth and potentiates the effects of cytotoxic therapy by nullifying drug resistance.

Original languageEnglish (US)
Pages (from-to)665-673
Number of pages9
Issue number10
StatePublished - Jan 1 2014



  • Antagonist
  • Combination therapy
  • Drug resistance
  • GHRH analogs
  • Growth-hormone-releasing hormone
  • Triple negative breast cancer

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

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