Induction of granulocyte-macrophage colony-stimulating activity by 12-O-tetradecanoylphorbol-13-acetate in SENCAR and B6C3F1 mice

• Published in: Carcinogenesis (New York) 1991-04, Vol.12 (4), p.735-739
• Main Authors: UPDYKE, L. W, YOON, H. L, PFEIFER, R. W
• Format: Article
• Language: English
• Subjects: Administration, Topical; Animals; Antigens, Surface - analysis; Biological and medical sciences; Bone Marrow - drug effects; Bone Marrow Cells; Carcinogenesis, carcinogens and anticarcinogens; Cell Count - drug effects; Chemical agents; Female; Flow Cytometry; Granulocyte-Macrophage Colony-Stimulating Factor - biosynthesis; Granulocyte-Macrophage Colony-Stimulating Factor - blood; Medical sciences; Mice; Mice, Inbred Strains - physiology; Skin - drug effects; Skin - metabolism; Spleen - cytology; Spleen - drug effects; Tetradecanoylphorbol Acetate - administration & dosage; Tetradecanoylphorbol Acetate - pharmacology; Tumors
• ISSN: 0143-3334; 1460-2180
• DOI: 10.1093/carcin/12.4.735

Previous studies in this laboratory and others have indicated that 12-O-tetradecanoylphorbol-13-acetate (TPA), the most potent skin tumor promoter known, evokes significantly greater inflammatory responses in phorbol ester-sensitive (SENCAR) mice compared to strains (e.g. C57BL/6 and B6C3F1) that are relatively resistant to the outgrowth of skin tumors in two-stage chemically induced carcinogenesis protocols. In the studies reported herein, subchronic topical application of TPA at doses relevant to two-stage protocols induced serum granulocyte-macrophage colony-stimulating activity (GM-CSA) in both SENCAR and B6C3F1 mice; however, the increase in SENCAR mice was significantly greater than that observed in the relatively resistant B6C3F1 strain (5-fold versus a 2-fold increase respectively). The greater increase in serum GM-CSA observed in SENCAR mice was correlated with a 31% increase in the number of splenic leukocytes that lacked both B and T cell surface markers (i.e. double-negative cells), a presumed GM progenitor cell; no significant increase in the relative percentage of such cells was observed in B6C3F1 mice. Alternatively, significant decreases in splenic T lymphocytes (23 and 32% in SENCAR and B6C3F1 respectively) were observed in both strains of TPA-treated mice and may, in part, account for the previously observed decreases in splenic cell blastogenic response to the T cell mitogen phytohemagglutinin (PHA). In vitro incubation of splenic cells from SENCAR mice with 0.01-1.0 microM TPA led to significantly greater increases in colony formation relative to splenic cells isolated from B6C3F1 mice; therefore, differences in the biochemical responsiveness between strains may occur at the level of signal transduction in splenic GM progenitor cells. In conclusion, these studies indicated that strain-dependent differences in the systemic inflammatory response following topical application of TPA may result from direct stimulation of splenic GM precursor cells by TPA and/or may occur, indirectly, through the release of cytokines [e.g. GM colony-stimulating factor (GM-CSF)] by induced epidermal (or other) cells.