Combined Anti-cancer Effects Of Multiple Antisense Oligodeoxynucleotides

In this study, the inhibitory effects on the proliferation of tumor cells after being treated with varied combinations of antisense phosphorothiate oligodeoxynucleotides (ASODNs) and the combinations of ASODN targeted to human telomerase reverse transcriptase (hTERT) mRNA named Cantide with chemotherapeutic drugs were investigated. The experiment methods and the statistic approaches were established to evaluate and analyse the combination effects of ASODNs.The following approaches were used in studying the inhibitory effects on tumor cells that were treated with combination of ASODNs: The targeted genes which involved the pathway of proliferation, death, apoptosis of cells and signal transduction were selected to synthesize ASODNs. These combinations that included 2 or 3 kinds of ASODNs per group were transfected into cells by lipofectin. Cell growth activity was evaluated by MTT assay. After analysis by the method of factor design, ANOVA, Q value and cluster, the combination of ASODN(hTERT) and ASODN(PKC- a ), the combination of ASODN(hTERT),ASODN(PKC- a ) and ASODN(IGF-IR) were the better ones.Based on the cytology test, the synergic groups were selected for Western Blot and RT-PCR to analyze the mechanism of combined ASODNs. And also according to the pathway analysis searched from internet database, the conclusion indicated that IGF-IR was upstream positive controlling PKC- a , and PKC- a was upstream positive controlling hTERT.The third part were involved in researching the inhibitory effects on tumor cells which were treated with combination of Cantide and chemotherapeutic agents. Cantide combined with cisplatin (DDP), 5-fluorouracil (5-FU) and adriamycin (ADM) were transfected into human hepatocellular carcinoma cells (HepG2), human gastric cells (BGC) and human lung adenocarcinoma cells (A549) by lipofectin. Cell growth activitywas evaluated by MTT assay. The results showed that the synergism was observed in these three combination treatments. And the group of Cantide and DDP appeared the best effect. In vivo, it was further proved that the combination of Cantide and DDP enhanced the inhibitory effect of tumor cells without apparent side effects.The approach of combination of ASODNs targeted to different mRNA which was closely relative to tumor occurrence, may enhance the inhibitory effects on proliferation of tumor cells. And the combination of ASODN and chemotherapeutic drugs appeared to increase the inhibitory effects on proliferation of tumor cells as well.