[Expression of growth hormone receptor in hepatocellular carcinoma and its significance]

Recombinant human growth hormone (rhGH) has been proved effective in clinic, such as promoting protein synthesis and decreasing the mortality. But there are still many arguments on whether it can be used in hepatocellular carcinoma (HCC) patients. rhGH cannot work except that it combines to its own receptor growth hormone receptor (GHR). The current study was designed to explore the expression of GHR in HCC tissues and to investigate the viability of rhGH for HCC treatment.

Radioreceptor assays were used to determine growth hormone receptor (GHR) in 40 HCC tissues; 6 normal liver tissues were used as control. Receptor binding capacity(RT) and affinity constant(Kd) of GHR were calculated by Scatchard's method; the relationship between RT of GHR in cancer and clinicopathologic factors were also analyzed.

The growth hormone- specific singular binding site, namely GHR, was detected respectively in 35 HCC cases and control tissues. The RT and Kd of GHR were 18.5416+/-4.1686 fmol/mg protein and 0.6319+/-0.1978 nmol/L in tumor tissues, 39.5467+/-3.4770 fmol/mg protein and 0.6167+/-0.1007 nmol/L in control tissues, respectively. Compared with the normal liver tissue, RT of GHR in tumor was lower (P< 0.05) but Kd did not show any difference(P >0.05). The RT of the GHR was negatively relevant to the tumor size and disease stage, but was not associated with differentiation of tumor, ages of the patients or whether the patient suffered from cirrhosis at the same time. GHR was undetectable in 5 cases.

This study showed that most of the HCC tissues express low levels of GHR. Before their functions are well understood, rhGH should be very carefully used in HCC patients.