Suppression of proline-directed protein kinase F(A) inhibits the malignant growth of human pancreatic ductal adenocarcinoma.
BACKGROUND
Proline-directed protein kinase F(A) (PDPK F(A)) was originally identified as a specific phosphatase activating factor, but has subsequently been demonstrated as a multisubstrate PDPK possibly involved in the regulation of diverse malignant characteristics of various types of human cancers including prostate, leukemia, bladder and colon cancers. However, the role of this PDPK in a lethal carcinoma, such as pancreatic ductal adenocarcinoma, remains to be established.


METHODS
The stable antisense clones with specific suppression of overexpressed PDPK F(A) of human pancreatic ductal adenocarcinoma cells (MIA PaCa-2) were first selected and subsequently characterized for the in vitro and in vivo growth studies.


RESULTS
The molecular and cellular studies revealed that the antisense clones of MIA PaCa-2 cells with specific suppression of overexpressed PDPK F(A) potentially exhibited cell growth retardation, decreased serum independence, poor clonogenic growth and loss of anchorage-independent growth. The in vivo study further confirmed that the SCID mice injected with the antisense clones with low-level PDPK F(A) did not develop any detectable tumors even after 7-week observation. In sharp contrast, the parental or control-transfected clones developed very large tumors (>5 cm3) under identical conditions.


CONCLUSIONS
The molecular, cellular and animal results taken together demonstrate that overexpressed PDPK F(A) is essential for the malignant growth of human pancreatic ductal adenocarcinoma.
Institute of Molecular and Cellular Biology and Department of Life Science, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC.
Hsiao-Hui
HH
Fu
Shiaw-Der
SD
Yang
D000818:Animals; D021441:Carcinoma, Pancreatic Ductal / Q000201:enzymology* / Q000235:genetics / Q000473:pathology*; D002455:Cell Division / Q000502:physiology; D016373:DNA, Antisense / Q000235:genetics; D005260:Female; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D010190:Pancreatic Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology*; D038461:Proline-Directed Protein Kinases / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D014162:Transfection; D014407:Tumor Cells, Cultured
D016373:DNA, Antisense; D038461:Proline-Directed Protein Kinases