摘要
OBJECTIVE To observe the effects of sense and antisense oligodeoxynucleotides of tankyrase 1 （TANK1-SODN and TANK1-ASODN） on murine tumor growth following intratumoral injection, investigate the actual suppressing result and mechanism of TANK1-ASODN on cancer cell proliferation, and discuss the possibility of using it in gene therapy on human lung cancer cells. METHODS After BALB/c nude mice had been subcutaneously inoculated with human lung cancer cell line CALU and it had grown into tumor nodules, we distributed these mice randomly into 3 groups： 4 in saline treatment group, and 5 each in TANK1-SODN group, and TANK1-ASODN groups. Then multiple direct intratumoral injections of synthesized TANK1-ASODN given continuously into tumor nodules for 16 days, this was compared with TANK1-SODN and saline control groups. During the experiment we measured the tumor volume every 5 days with vernier calipers; observed the histopathological characteristics of tumor tissues under microscope; went further to detect the minute changing of ultrastructure of cancer cells by electron microscope; tested the expression levels of ki67 and hTERT protein by means of SABC immunohistochemical method; and detected the lung cancer cells＇ hTERT mRNA expression level by hybridization in situ （ISH） in each group. RESULTS After 16 days of continuous injection, the tumor volume in TANK1-ASODN group was significantly smaller than the other 2 groups （both P 〈 0.01）; quite a lot of tumor cell degeneration and necrosis were observed in mice given TANK1-ASODN. The results of electron microscope also showed that TANK1-ASODN has the power to kill cancer cells in various ways. Moreover, statistically signi.cant decreases in the positive expression ratio of Ki67 Labeling Index （P 〈 0.01）, hTERT protein （P 〈 0.01）, and hTERT mRNA （P 〈 0.01） were consistently observed in the TANK1-ASODN group. CONCLUSION Human lung cancer cell line CALU expressed high telomerase activity. TANK1-ASODN had the ability to decline the high expression level of hTERT; inhibit the activity of telomerase, accelerate tumor cell degeneration and necrosis; and then suppress the proliferation of cancer cells.
