Distinct progression pathways involving the dysfunction of DUSP6/MKP-3 in pancreatic intraepithelial neoplasia and intraductal papillary-mucinous neoplasms of the pancreas.
DUSP6/MKP-3 is identified as a candidate tumor suppressor gene for pancreatic cancer. The aim of this study was to elucidate the roles of DUSP6 in the pancreatic carcinogenesis through the pancreatic intraepithelial neoplasia and/or intraductal papillary-mucinous neoplasms, both of which are considered to be precursor lesions of invasive carcinoma of the pancreas, by comparing with involvements of other major tumor suppressive pathways. Expressions of DUSP6, CDKN2A, TP53, and SMAD4 were investigated by immunohistochemistry in a total of 206 lesions of dysplastic ductal precursors and carcinomas retrieved from 52 pancreata with invasive ductal carcinomas and 51 of those with intraductal papillary-mucinous neoplasms. The intensity of staining was evaluated in lesions at different atypical grades and statistically compared among them. Mutations of KRAS2 were analyzed by methods of the allele-specific oligonucleotide hybridization and nucleotide sequencing. In pancreata with invasive ductal carcinomas, expressions of DUSP6 were abrogated exclusively in the invasive carcinoma cells in contrast to its fairly preserved expressions in pancreatic intraepithelial neoplasia. In pancreata with intraductal papillary-mucinous neoplasms, abrogated expressions of DUSP6 were observed in a relatively small fraction of intraductal adenoma/borderlines and intraductal carcinomas. Most of the intraductal adenoma/borderline lesions with abrogation of DUSP6 harbored mutations of KRAS2. None of the molecules was associated with each other in any grade of lesions. Morphological variations of papillae of the intraductal papillary-mucinous neoplasms were evaluated and analyzed for their associations with abrogations of the molecules, which resulted in finding of no significant associations. Our results suggest that the abrogation of DUSP6 is associated exclusively with progression from pancreatic intraepithelial neoplasia to the invasive ductal carcinoma while it is potentially associated with initiation of intraductal papillary-mucinous neoplasms with mutated KRAS2, which is independent of other major tumor suppressive pathways in both types of neoplasms.
Furukawa
Toru
T
Department of Molecular Pathology, Tohoku University School of Medicine, Sendai, Japan. furukawa@mail.tains.tohoku.ac.jp
Fujisaki
Rumi
R
Yoshida
Yoshitaro
Y
Kanai
Naomi
N
Sunamura
Makoto
M
Abe
Tadayoshi
T
Takeda
Kazunori
K
Matsuno
Seiki
S
Horii
Akira
A
D002288:Adenocarcinoma, Mucinous / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D000231:Adenocarcinoma, Papillary / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D021441:Carcinoma, Pancreatic Ductal / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism; D004252:DNA Mutational Analysis / Q000379:methods; D004268:DNA-Binding Proteins / Q000378:metabolism; D018450:Disease Progression; D054642:Dual Specificity Phosphatase 6; D006801:Humans; D007150:Immunohistochemistry; D009154:Mutation; D010183:Pancreatic Ducts / Q000378:metabolism / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D011230:Precancerous Conditions / Q000378:metabolism / Q000473:pathology*; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000235:genetics; D016283:Proto-Oncogene Proteins p21(ras); D015398:Signal Transduction; D051901:Smad4 Protein; D015534:Trans-Activators / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D018631:ras Proteins
D019941:Cyclin-Dependent Kinase Inhibitor p16; D004268:DNA-Binding Proteins; C117307:KRAS protein, human; D011518:Proto-Oncogene Proteins; C497796:SMAD4 protein, human; D051901:Smad4 Protein; D015534:Trans-Activators; D016159:Tumor Suppressor Protein p53; C517035:DUSP6 protein, human; D054642:Dual Specificity Phosphatase 6; D017027:Protein Tyrosine Phosphatases; D016283:Proto-Oncogene Proteins p21(ras); D018631:ras Proteins