γ-IFN诱导神经母细胞瘤细胞分化及TrKA表达的实验研究

DIFFERENTIATION AND TrKA ONCOGENE EXPRESSION IN NEUROBLASTOMA CELL LINE INDUCED BY γ-IFN

本实验观察不同浓度的γ IFN对NB细胞产生增殖抑制及诱导分化作用时 ,TrkAmRNA表达的变化 ,及其与增殖抑制、分化程度的关系。首先应用 ,常规培养SMS KCNR细胞 ;然后用三种不同浓度的γ IFN处理这些细胞 ;在不同的作用时间 ,通过台盼蓝拒染实验判定γ IFN对NB细胞的的增殖抑制作用及相差显微镜观察NB细胞形态学变化 ;用RNA PCR及SouthernBlot杂交法检测γ IFN对NB细胞的Tr kAmRNA表达的影响。结果表明 :( 1 ) 1 0 0 0IU/ml、2 0 0 0IU/mlγ IFN对人NB细胞的体外增殖有抑制作用。 ( 2 )γ IFN可诱导NB细胞分化成熟及TrkAmRNA表达水平增高 ,其作用随时间延长 ,浓度增加而增强。结论 :( 1 )γ IFN能够抑制NB细胞增殖并诱导其分化 ,同时TrkAmRNA表达增加 ,其作用效应 ,呈量效依赖关系。 ( 2 )TrkAmRNA表达水平的增高可能是γ

Interferon is one of the candidates to play a role in the differentiation and the growth inhibition of neuroblastoma cells because γ Interferon can normally induce the expression of TrKA mRNA, and the levels of TrKA mRNA increased can cause the growth inhibition and morphological change in neuroblastoma cells. That is one of the biomolecular mechanisms for neuroblastoma cells' differentiation and several investigators have shown that high expression of TrKA mRNA appears to be associated with favorable outcome in human neuroblastoma. In this experiments, SMS KCNR neuroblastoma cell line was examined to determine the effect of recombinant γ IFN treatment on the expression of TrKA proto oncogene and on the growth inhibition and morphological change. At the same time, we analyzed the relationship of them. Morphological differentiation is observed under the phase contrast microscope. Morphological changes characterized as neurite outgrowth more than two times as diameter of a simple cell; Results showed: Morphological differntiation was induced and cell growth was inhibited in SMS KCNR neuroblastoma cell line after the treatmeat of γ IFN. The expression of TrKA mRNA was changed and the level of TrKA mRNA increased during cell differentiation. The intension of the cells' differentiation and level of TrKA mRNA increased in a dose and time dependent manner after the treatment of γ IFN. The specificity of PCR products is very high. In conclusion: γ IFN can inhibite cell growth and induce morphological differentiation of SMS KCNR neuroblastoma cell line and it may be applied as a therapeutic agent. Expression of TrKA oncogene was increased during cell differentiation and that may be one of the biomolecular mechanisms for neuroblastoma cells' differentiation. TrKA may actively promote growth arrest and may be an important therapeutic target in the treatment of this disease.