DCK is frequently inactivated in acquired gemcitabine-resistant human cancer cells
| Autor: | Miki Shimada, Shinichi Fukushige, Shinichi Egawa, Tomohiro Nakano, Nariyasu Mano, Sho Fujiwara, Zhaleh Kashkouli Nezhad, Na Chen, Shinjiro Shimizu, Hiroko Fujimura, Fuyuhiko Motoi, Guo Jin, Shinya Oba, Michiaki Unno, Yoonha Lee, Hideyuki Shimizu, Masaharu Ishida, Yuriko Saiki, Yuki Yoshino, Makoto Sunamura, Akira Horii, Yuki Kudo, Tatsuya Manabe |
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| Rok vydání: | 2012 |
| Předmět: |
Antimetabolites
Antineoplastic Biophysics Gene Expression Biology medicine.disease_cause Biochemistry Deoxycytidine Histones chemistry.chemical_compound Pancreatic cancer Cell Line Tumor Deoxycytidine Kinase medicine Neoplasm Humans Gene Silencing Phosphorylation RNA Small Interfering Molecular Biology Gene knockdown Mutation Cell Biology Deoxycytidine kinase medicine.disease Gemcitabine Pancreatic Neoplasms chemistry Cell culture Drug Resistance Neoplasm Gene Knockdown Techniques Immunology Cancer research medicine.drug |
| Zdroj: | Biochemical and biophysical research communications. 421(1) |
| ISSN: | 1090-2104 |
| Popis: | Although gemcitabine is the most effective chemotherapeutic agent against pancreatic cancer, a growing concern is that a substantial number of patients acquire gemcitabine chemoresistance. To elucidate the mechanisms of acquisition of gemcitabine resistance, we developed gemcitabine-resistant cell lines from six human cancer cell lines; three pancreatic, one gastric, one colon, and one bile duct cancer. We first analyzed gemcitabine uptake using three paired parental and gemcitabine resistant pancreatic cancer cell lines (PK-1 and RPK-1, PK-9 and RPK-9, PK-59 and RPK-59) and found that uptake of gemcitabine was rapid. However, no DNA damage was induced in resistant cells. We further examined the microarray-based expression profiles of the cells to identify genes associated with gemcitabine resistance and found a remarkable reduction in the expression of deoxycytidine kinase (DCK). DCK is a key enzyme that activates gemcitabine by phosphorylation. Genetic alterations and expression of DCK were studied in these paired parental and derived gemcitabine-resistant cell lines, and inactivating mutations were found only in gemcitabine-resistant cell lines. Furthermore, siRNA-mediated knockdown of DCK in the parental cell lines yielded gemcitabine resistance, and introduction of DCK into gemcitabine-resistant cell lines invariably restored gemcitabine sensitivities. Mutation analyses were expanded to three other different paired cell lines, DLD-1 and RDLD-1 (colon cancer cell line), MKN-28 and RMKN-28 (gastric cancer cell line), and TFK-1 and RTFK -1 (cholangiocarcinoma cell line). We found inactivating mutations in RDLD-1 and RTFK-1 and decreased expression of DCK in RMKN-28. These results indicate that the inactivation of DCK is one of the crucial mechanisms in acquisition of gemcitabine resistance. |
| Databáze: | OpenAIRE |
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