Transforming growth factor-beta in in vivo resistance

Cancer Chemother Pharmacol. 1996;37(6):601-9. doi: 10.1007/s002800050435.


The potential role of transforming growth factor-beta in in vivo resistance was examined by administration of transforming growth factor-beta-neutralizing antibodies to animals bearing the EMT-6/Parent tumor or the antitumor alkylating resistance tumors, EMT-6/CTX or EMT-6/CDDP. Treatment of tumor bearing animals with anti-TGF-beta antibodies by intraperitoneal injection daily on days 0-8 post-tumor cell implantation increased the sensitivity of the EMT-6/Parent tumor to cyclophosphamide (CTX) and cisplatin (CDDP) and markedly increased the sensitivity of the EMT-6/CTX tumor to CTX and the EMT6/CDDP tumor to CDDP, as determined by tumor cell survival assay. Bone marrow granulocyte-macrophage colony-forming units (CFU-GM) survival was determined from these same animals. The increase in the sensitivity in the tumors upon treatment with the anti-TGF-beta antibodies was also observed in increased sensitivity of the bone marrow CFU-GM to CTX and CDDP. Treatment of non-tumor-bearing animals with the anti-TGF-beta regimen did not alter blood ATP or serum glucose level but did decrease serum lactate levels. This treatment also decreased hepatic glutathione, glutathione S-transferase, glutathione reductase, and glutathione peroxidase in non-tumor bearing animals by 40-60% but increased hepatic cytochrome P450 reductase in these normal animals. Animals bearing the EMT-6/CTX and EMT-6/CDDP tumors had higher serum lactate levels than normal or EMT-6/Parent tumor-bearing animals; these were decreased by the anti-TGF-beta regimen. Treatment of animals bearing any of the three tumors with the anti-TGF-beta regimen decreased by 30-50% the activity of hepatic glutathione S-transferase and glutathione peroxidase, and increased by 35-80% the activity of hepatic cytochrome P450 reductase. In conclusion, treatment with transforming growth factor-beta-neutralizing antibodies restored drug sensitivity in the alkylating agent-resistant tumors, altering both the tumor and host metabolic states.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antineoplastic Agents, Alkylating / therapeutic use*
  • Bone Marrow Cells
  • Cell Survival / drug effects
  • Drug Resistance, Multiple*
  • Female
  • Glutathione / metabolism
  • Hematopoiesis / drug effects
  • Liver / enzymology
  • Mammary Neoplasms, Experimental / drug therapy*
  • Mammary Neoplasms, Experimental / metabolism
  • Mice
  • Mice, Inbred BALB C
  • Transforming Growth Factor beta / physiology*


  • Antineoplastic Agents, Alkylating
  • Transforming Growth Factor beta
  • Glutathione