The Influences Of Nitric Oxide On The Invasive And Metastatic Ability Of Osteosarcoma Cells

[Objectives] A series of experiments were conducted to evaluate: the effect of NO on the invasive and metastatic abilities of human osteosarcoma cell line (HOS-8603); the relation between the activity of iNOS and the contents of NO in osteosarcoma tissue and normal tissue; the content change of NO in blood before and after the resection of osteosarcoma; the relation between iNOS and CD44 expression in human osteosarcoma. The final purpose of all these studies was to explore the relation between NO and the invasive and metastatic abilities of osteosarcoma. [Methods] Different concentrations of SNP were added into the culture solution of HOS in vitro and 2.5mg/O.lrril L-NAME, a depressor of NOS, was injected into the experimental mice in different time. The invasive and metastatic ability of HOS was observed in vitro and in vivo. O.O1M PBS was used as control instead of SNP. Osteosarcoma specimens and normal soft tissue specimens were gathered. The activity of NOS and the content of NO were measured. NO in some preoperative and postoperative blood specimens of osteosarcoma were tested by colorimetric method. The control blood samples were gained from normal blood donors. Some specimens of osteosarcoma were divided into two groups: with metastasis and without metastasis. The expression of iNOS and CD44 in these specimens was stained by immunohistochemistry method. The intensity of color was expressed by score. Human normal cancellous bone was used as control.Datum were all analyzed statistically with SPSS software. I Results I Vitality of HOS was significantly depressed when the concentration of SNP was over 200 it M and there was significant difference between these groups (p0.05). iNOSand CD44 were expressed in either group witI1 metastasis or group withoutmetastasis, but the intensity of these expression was different. In group withmetastasis, the expression of iNOS and CD44 was more intensive than that ingroup without metastasis.[Conclusions] Exogenous NO could depress tl1e vitality and invasive ormetastatic ability of HOS in vivo and in vitro. NO in osteosarcoma was notgenerated by the local tissues. It maybe come fto1n the other parts of the bodyand concentrated in the neopIasm. The variety of NO in preoperative andpostoperative osteosarcoma blood might reflect an adaptable change whenbeing invaded by osteosarcoma. iNOS and CD44 had some relations with thegrade and invasive ability of osteosarcoma. Tl1e measurement of thesesubstances could help to analyze the clinic prognosis and pathologicdevelopment of osteosaI'coma.