Differential Sensitivity of Human Hepatocellular Carcinoma Xenografts to an IGF-II Neutralizing Antibody May Involve Activated STAT3

Sameer A. Greenall, Jacqueline Donoghue, Terrance G. Johns, Timothy E. Adams

Research output: Contribution to journalArticleResearchpeer-review

2 Citations (Scopus)

Abstract

Hepatocellular carcinoma (HCC) is highly refractory to current therapeutics used in the clinic. DX-2647, a recombinant human antibody, potently neutralizes the action of insulin-like growth factor-II (IGF-II), a ligand for three cell-surface receptors (IGF-IR, insulin receptor A and B isoforms, and the cation-independent mannose-6-phosphate receptor) which is overexpressed in primary human HCC. DX-2647 impaired the growth of tumor xenografts of the HCC cell line, Hep3B; however, xenografts of the HCC cell line, HepG2, were largely unresponsive to DX-2647 treatment. Analysis of a number of aspects of the IGF signaling axis in both cell lines did not reveal any significant differences between the two. However, while DX-2647 abolished phospho (p)-IGF-IR, p-IR and p-AKT signaling in both cell lines, HepG2 showed high levels of p-STAT3, which was unaffected by DX-2647 treatment and was absent from the Hep3B cell line. The driver of p-STAT3 was found to be a secreted cytokine, and treatment of HepG2 cells with a pan- JAK kinase inhibitor resulted in a loss of p-STAT3. These findings implicate the activation of STAT3 as one pathway that may mediate resistance to IGF-II–targeted therapy in HCC.

Original languageEnglish
Pages (from-to)971-978
Number of pages8
JournalTranslational Oncology
Volume11
Issue number4
DOIs
Publication statusPublished - 1 Aug 2018

Keywords

  • IGF-II
  • antibody therapy
  • resistance
  • STAT3
  • signalling
  • hepatocellular carcinoma
  • Bioavailability

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