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Enhanced therapeutic effects for human pancreatic cancer by application K-ras and IGF-IR antisense oligodeoxynucleotides

2008; Baishideng Publishing Group; Volume: 14; Issue: 33 Linguagem: Inglês

10.3748/wjg.14.5176

2219-2840

Yongmei Shen, Xiaochun Yang, Yang Chen, Junkang Shen,

Growth Hormone and Insulin-like Growth Factors

AIM:To investigate the combined effects of K-ras antisense oligodeoxynucleotide (K-ras ASODN) specific to GTT point mutation at codon 12 and type Ⅰ insulin-like growth factor receptor (IGF-IR) antisense oligodeoxynucleotide (IGF-IR ASODN) on proliferation and apoptosis of human pancreatic cancer Patu8988 cells in vitro and in vivo .METHODS: K-ras gene point mutation and its style at codon 12 of human pancreatic cancer cell line Patu8988 were detected by using polymerase chain reaction with special sequence primers (PCR-SSP) and sequence analysis.According to the mutation style, K-ras mutation ASODN specific to K-ras point mutation at codon 12 was designed and composed.After K-ras ASODN and IGF-IR ASODN treated on Patu8988 cells respectively or cooperatively, the proliferation and morphological change of Patu8988 cells were analyzed by 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, colony forming assay and transmission electron microscopy; the expression of K-ras and IGF-IR mRNA and protein in the treated cells was measured by reversetranscript polymerase chain reaction (RT-PCR) and flow cytometry respectively; apoptosis was determined by flow cytometry.The combined antitumor activity of K-ras ASODN and IGF-IR ASODN was evaluated in BALB/c nude mice bearing human pancreatic cancer inoculated with Patu8988 cells. RESULTS:The results of PCR-SSP and sequence analysis showed that the human pancreatic cancer cell line Patu8988 had point mutation at codon 12, and the mutation style was GGT→GTT.2-32 μg/mL K-ras ASODN and 2-32 μg/mL IGF-IR ASODN could inhibit Patu8988 cells' growth, induce apoptosis and decrease the expression of K-ras and IGF-IR mRNA and protein alone.However, there was much more effective inhibition of growth and induction of apoptosis by their combination than by each one alone.In tumor bearing mice, the combination of K-ras ASODN and IGF-IR ASODN showed a significant inhibitory effect on the growth of transplanted pancreatic cancer, resulting in a statistically significant difference compared with each alone.CONCLUSION: It has been found that K-ras ASODN combined with IGF-IR ASODN could cooperatively inhibit the growth of Patu8988 cells, and induce their apoptosis via reinforcing specific down regulation of K-ras and IGF-IR mRNA and protein expression.