Additionally, we show that plasma levels of cleaved IR reflect IR isoform A expression levels in liver tumors, which prompts us to propose that the measurement of circulating cleaved IR may assist hepatic cancer detection and management.
Additionally, we show that plasma levels of cleaved IR reflect IR isoform A expression levels in liver tumors, which prompts us to propose that the measurement of circulating cleaved IR may assist hepatic cancer detection and management.
We next studied HTC-IR(Delta485-599) cells, which overexpress a mutant IR with a deletion in the alpha-subunit connecting domain that does not undergo autophosphorylation in response to insulin binding.
Failure to replace complete medium resulted in growth arrest of HepG2 cells and a six- to sevenfold increase in insulin-receptor mRNA due to the prolongation of insulin-receptor mRNA half-life.
Only very high concentrations of insulin-like growth factor I and human proinsulin can compete for the insulin receptor binding and suppress HBsAg production, this suggests that insulin may act through its receptor binding to suppress HBsAg expression in human hepatoma Hep3B cells.
We have now constructed a human insulin receptor mutant in which 3 residues in this sequence were altered (Thr-Cys-Pro-Pro-Pro-Tyr-Tyr-His-Phe-Gln-Asp to Thr-Cys-Pro-Arg-Arg-Tyr-Tyr-Asp-Phe-Gln-Asp) and have expressed this mutant in rat hepatoma (HTC) cells.