Background & objective: Recombinant human growth hormone (rhGH) has been widely used in clinical medicine; while for the patients with hepatocellular carcinoma (HCC), if rhGH could cause tumor growth, metastasis or recurrence other than improve patients' body condition is uncertain. Because most primary hepatic carcinoma could express human growth hormone receptor (GHR), this study was to explore the effects of rhGH on the growth of human Bel-7402 hepatic carcinoma (with GHR expression) xenograft in nude mice.
Methods: The expression of GHR was confirmed in Bel-7402 cells by radioligand assay. After transplantation of Bel-7402 hepatic carcinoma in liver, 32 nude mice were randomly divided into 4 groups. Except 1 control group, 3 experimental groups were injected with different dosages of rhGH [0.5, 1.0, and 2.0 U . (kg.day)(-1), respectively] subcutaneously 2 weeks after tumor transplantation, once a day for 2 weeks. All nude mice were killed at the end of the experiment to observe the growth of xenografts. The expression of proliferating cell nuclear antigen (PCNA) in xenografts was examined by immunochemistry.
Results: The tumor weight was significantly heavier and the tumor volume was significantly larger in 1.0 U . (kg.day)(-1) rhGH and 2.0 U . (kg.day)(-1) rhGH groups than in control group (P<0.05), but no significant difference was found between 0.5 U . (kg.day)(-1) rhGH group and control group (P>0.05). Labeling index (LI) of PCNA was significantly higher in each experimental group than in control group (P<0.05), and significant differences were also found among the 3 experimental groups (P<0.05). The dosage of rhGH was positively correlated to LI of PCNA in tumor tissues (r=0.779, P<0.001).
Conclusions: rhGH could enhance the growth of Bel-7402 hepatic carcinoma xenografts in nude mice. Its effect positively correlates with rhGH dosage.