Expression profiles of pancreatic cancer cell lines infected with antisense K- ras-expressing adenoviral vector

• Published in: Biochemical and biophysical research communications 2003-10, Vol.309 (4), p.798-803
• Main Authors: Ohnami, Shumpei, Aoki, Kazunori, Yoshida, Kimiko, Ohnami, Sumiko, Hatanaka, Kazuteru, Suzuki, Koichi, Sasaki, Hiroki, Yoshida, Teruhiko
• Format: Article
• Language: English
• Subjects: Adenoviral vector; Adenoviridae - genetics; Antisense RNA; Base Sequence; Cell Line, Tumor; DNA Primers; Gene Expression Profiling; Gene Expression Regulation, Neoplastic - genetics; Genes, ras; Genetic Vectors; Humans; K- ras; Microarray; Mutation; Oligonucleotide Array Sequence Analysis; Pancreatic cancer; Pancreatic Neoplasms - genetics; Reverse Transcriptase Polymerase Chain Reaction; RNA, Antisense - genetics
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2003.08.073

The point mutations of the K- ras gene occur in as high as 70–90% of the cases with adenocarcinoma of the pancreas and apparently represent one of the key and early events in the carcinogenesis. However, the specific influence of the K- ras activation on global gene expression profiles in pancreatic cancer cells has not been elucidated. In this study, to promote elucidation of the K- ras-triggered molecular cascade(s) in pancreatic cancer, four pancreatic cancer cell lines with K- ras point mutations were infected with an adenovirus vector expressing an antisense K- ras RNA (AxCA-AS), and the change of gene expression was analyzed by oligonucleotide-based microarrays containing 12,626 genes. Among the genes showing more than 2-fold differences in the expression levels between the control- and antisense-K- ras-transduced cells, 7 genes were commonly up-regulated and 4 genes were commonly down-regulated in three or all of the four pancreatic cancer cell lines transduced with AxCA-AS. The altered gene expression levels observed by microarrays were confirmed by real-time RT-PCR methods. Then, the expression of the 4 down-regulated genes was examined in the untransduced surgical specimens of pancreatic cancer. The G-protein coupled receptor RE2 and phenylethanolamine N-methyltransferase had negligible expression levels in all pancreatic cancers, whereas the syntaxin 1A and p120 catenin isoform were significantly up-regulated in pancreatic cancers containing K- ras mutations compared with a pancreatic cancer with wild type K- ras gene. The transcriptional regulation of those genes may be a part of the molecular cascades triggered by K- ras activation leading to the development and/or progression of pancreatic cancer.