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-dimethylthiazol-2-y1)-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 reverse-transcript polymerase chain reaction(RT-PCR)and flow cytometry respectively;apoptosis was determined by flow cytometry.The combined antitumor activity of K-ras ASODN and IGFIR 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 Dancreatic cancer cell line Patu8988 had point mutation at coclon 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 difierence 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.(c)2008 The WJG Press.All rights reserved.