These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: 1 alpha,25-dihydroxyvitamin D3 plus gamma-interferon blocks lung tumor production of granulocyte-macrophage colony-stimulating factor and induction of immunosuppressor cells. Author: Young MR, Halpin J, Wang J, Wright MA, Matthews J, Pak AS. Journal: Cancer Res; 1993 Dec 15; 53(24):6006-10. PubMed ID: 8261414. Abstract: Metastatic Lewis lung carcinoma (LLC-LN7) cells have previously been shown to produce granulocyte-macrophage colony-stimulating factor (GM-CSF) which induces the appearance of immunosuppressive granulocytic-macrophage progenitor cells (GM-suppressor cells). The present in vitro studies showed that treatment of LLC-LN7 tumor cells with 1 alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3] plus low dose gamma-interferon (IFN-gamma) resulted in a synergistic reduction in tumor GM-CSF secretion and a blockage in the capacity of the tumor cells to induce GM-suppressor cells. The production of GM-CSF by bulk cultures of enzymatically dissociated LLC-LN7 tumors that had been excised as s.c. tumors from mice was also blocked when the dissociated tumor was cultured with 1,25(OH)2D3 plus IFN-gamma. Our previous and present studies showed that GM-suppressor cells persist in bulk cultures of dissociated LLC-LN7 tumors after a 1-week period of culture. Addition of either 1,25(OH)2D3 or IFN-gamma did not diminish the persistence of GM-suppressor cells. However, when tumor production of GM-CSF was inhibited by culture with both 1,25(OH)2D3 and IFN-gamma, the ability of the dissociated tumor culture to sustain the presence of GM-suppressor cells was blocked. This elimination of GM-suppressor cells by treatment of the dissociated tumor with 1,25(OH)2D3 and IFN-gamma coincided with increased expansion of CD8+ tumor-infiltrating leukocytes and increased cytotoxic T-lymphocytes activity of tumor-infiltrating lymphocytes. These results suggest that blocking tumor production of GM-CSF can interrupt the suppressor-inducing cascade of the tumor and enhance expansion and anti-tumor cytolytic reactivity of tumor-infiltrating leukocytes.[Abstract] [Full Text] [Related] [New Search]