Adaptor Protein Crk is Implicated in Mucus Formation in Mucinous Epithelial Ovarian Cancer (mEOC) Cells MCAS

Objective： The mucus production is an indicator for the histological grade of mucinous epithelial ovarian cancer （mEOC）. In our previous study, Crk expression was targeted in the human ovarian mucinous adenocarcinoma cell line MCAS through RNA interference, resulting in the establishment of Crk knock down cells. These cells exhibited decreased tumorigenic potential both in vitro and in vivo. The purpose of this study was to investigate if there is any change in the capability of forming mucus in these Crk knock down cells. Methods： Cytoplasmic periodic acid Schiff （PAS） staining and particle excluding assay were conducted to assess the mucus formation within and around cells, respectively. Additionally, the amount of mucus formed in tumor lumps from nude mice model was measured following HE and PAS staining. Results： The increased mucus production in Crk knockdown mEOC cells （MCAS） was manifested by increased number of enlarged cells filled with vacuoles-like mucus observed by phase-contrast microscope and cytoplasmic PAS staining; and enhanced mucus secretion was represented by the assembly of pericellular matrix in particle excluding assay and increased mucus area in tumor lumps from nude mice models. Conclusion： The course of carcinogenesis in mEOC is associated with the altered pattern of mucus production and secretion. The adaptor protein Crk is implicated in both pathways.

Pancreatic Carcinoma with Prominent Mucin Production: A Clinicopathologic and Immunohistochemical Study of 9 Cases

Pancreatic carcinoma occasionally associated with prominent mucin production and this type of tumor designated as PCM (pancreatic carcinoma with prominent mucin production) was diagnosed depends on subjective estimation of the amount of mucous area, and there has been no report on a quantitative evaluation of the amount of mucinous area in the tumor. To examine the feature of PCM, we analyzed 9 cases of PCM among 243 cases of pancreas carcinoma and evaluated the amount of mucin by imaging analysis. Morphologically, 5 cases were classified as intradactal papillary mucinous neoplasms (IPMN)-derived PCM and 4 cases were as ductal adenocarcinoma (DA)-derived PCM. Mucous composition was found to be more than 50% in all IPMN-derived PCM cases, and that was 40% - 50% in DA-derived PCM cases with one exception. IPMN-derived PCM cases showed expansive growth with pancreatic duct dilatation filled with mucin, while DA-derived PCM cases possessed mucin infiltration into interstitial tissue. Immunohisto-chemically, three of 4 DA-derived PCM cases were MUC1(–)/MUC2(+), and the results of expressions for p16 and Dpc4 suggesting that DA-derived PCM was similar to IPMN-derived PCM rather than ordinary DA. Survival rate of DA-derived PCM cases was lower than that of IPMN-derived PCM cases. We advocate that DA-derived PCM may constitute a borderline group between IPMN and ordinary DA.