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为研究表达反义c－mycRxA的逆转录病毒载体抑制靶基因的表达和翻译，使胰腺癌细胞恶性表型逆转的机理，利用PXTI逆转录病毒载体构建了一个能表达反义c－mycRNA的质粒，经病毒包装细胞PA317包装后，使之成为具有感染力的重组病毒。用该病毒感染人胰腺癌细胞系PC－2细胞，经G418筛选得到稳定的转化细胞系。Northernblot杂交证实包装细胞PA317及转化的PC－2细胞中均有病毒的高表达，体外合成的单链RNA探针杂交结果表明转化PC－2细胞中有高表达的反义c－mycRNA，而内源性c－mycRNA的表达明显受抑；Westernblot分析发现c－myc癌基因产物P62蛋白的表达显著下降。反义c－mycRNA使人胰腺癌细胞生长速率、~3H-胸腺嘧啶掺入、软琼脂集落形成能力以及探鼠致瘤能力等均明显下降。实验结果表明：表达反义c－mycRNA的逆转录病毒载体能有效地抑制靶基因的表达和翻译，使胰腺癌细胞恶性表型部分逆转。
To study the mechanism that the retrovirus vector expressing antisense c-mycRxA inhibits the expression and translation of target genes and reverses the malignant phenotype of pancreatic cancer cells, a plasmid expressing antisense c-mycRNA was constructed using the PXTI retrovirus vector. After packaging by viral packaging cells PA317, it became an infectious recombinant virus. The virus was used to infect human pancreatic cancer cell line PC-2 cells, and a stable transformed cell line was obtained by G418 selection. Northern blot hybridization demonstrated high expression of virus in both packaging cell PA317 and transformed PC-2 cells. In vitro hybridization results of single-stranded RNA probes showed high expression of antisense c-mycRNA in transformed PC-2 cells. The expression of c-mycRNA was significantly inhibited; Western blot analysis showed that the expression of c-myc oncogene product P62 protein significantly decreased. Antisense c-mycRNA significantly decreased the growth rate of human pancreatic cancer cells, the incorporation of ~3H-thymidine, the formation of soft agar colonies, and the tumorigenicity of mice. The experimental results show that the retroviral vector expressing antisense c-mycRNA can effectively inhibit the expression and translation of target genes and reverse the malignant phenotype of pancreatic cancer cells.