[Down regulation of mitogen activated protein kinase phosphatase-1 mediate acquired multidrug resistance in pancreatic adenocarcinoma cell line SW1990/Fu].
OBJECTIVE
To investigate the role of mitogen activated protein kinase phosphatase-1 (MKP-1) in mediating acquired multidrug resistance in pancreatic adenocarcinoma cell line SW1990/Fu.


METHODS
To detect MKP-1 mRNA expression, Northern blot analysis was carried out in well established drug resistant pancreatic adenocarcinoma cell line SW1990/Fu, SW1990 and MiaPaCa-2 cell lines. To further elucidate the exact role of MKP-1, Western blot hybridization was performed in these three cell lines.


RESULTS
Northern blot analysis of total RNA isolated from SW1990/Fu, SW1990 and MiaPaCa-2 cell lines revealed the presence of the 2400 bp MKP-1 transcript 7 at relatively high levels in pancreatic cancer cell lines SW1990 and MiaPaCa-2. In the SW1990/Fu, the MKP-1 transcript was detectable at very low level. Densitometric analysis with normalization to 7S indicated that MKP-1 mRNA expression level was significantly decreased in SW1990/Fu in comparison with the parental and MiaPaCa-2 cell lines. MKP-1 protein expression level in SW1990/Fu detected by Western blot was coincident with mRNA level.


CONCLUSIONS
MKP-1 may be involved in acquired multidrug resistance in pancreatic adenocarcinoma, and we could hypothesized that alterations of intra-cellular transduction signal system acts as an important role in multidrug resistance of tumor cells.
Guo
Jun-chao
JC
Department of General Surgery, Peking Union Medical College Hospital, Beijing 100730, China.
Zhao
Yu-pei
YP
Liao
Quan
Q
Chen
Ge
G
Zhu
Yu
Y
D000230:Adenocarcinoma / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D015152:Blotting, Northern; D015153:Blotting, Western; D018797:Cell Cycle Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D045744:Cell Line, Tumor; D015536:Down-Regulation; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D054638:Dual Specificity Phosphatase 1; D006801:Humans; D017874:Immediate-Early Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D010190:Pancreatic Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D010749:Phosphoprotein Phosphatases / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D054645:Protein Phosphatase 1; D017027:Protein Tyrosine Phosphatases / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics
D018797:Cell Cycle Proteins; D017874:Immediate-Early Proteins; D012333:RNA, Messenger; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1; C517019:DUSP1 protein, human; D054638:Dual Specificity Phosphatase 1; D017027:Protein Tyrosine Phosphatases