Wilms tumor gene protein 1 is associated with ovarian cancer metastasis and modulates cell invasion.
BACKGROUND
Although metastatic disease is the primary cause of death from epithelial ovarian carcinoma, to the authors' knowledge the cellular mechanisms that regulate intraperitoneal metastasis are largely unknown. Metastasizing ovarian carcinoma cells encounter a collagen-rich microenvironment because the submesothelial matrix is comprised mainly of interstitial collagens Types I and III.


METHODS
Immunohistochemistry using primary and metastatic ovarian carcinoma samples was employed to detect expression of Wilms tumor gene protein 1 (WT1). Three-dimensional (3D) collagen culture, real-time reverse transcriptase-polymerase chain reaction, and immunofluorescent staining were used to evaluate changes in WT1 RNA and protein expression in response to 3D collagen culture. Boyden chamber invasion assay, scratch-wound motility assay, and Western blot analysis were used to establish the function of WT1 in ovarian carcinoma cells.


RESULTS
To model intraperitoneal invasion in vitro, ovarian cancer cells were cultured in a 3D collagen microenvironment. 3D collagen culture resulted in robust induction of WT1 at the mRNA and protein levels. WT1 expression was prevalent in primary ovarian tumors and was retained in paired peritoneal metastases. Functional studies supported a role for WT1 in intraperitoneal invasion, because siRNA knockdown of WT1 expression reduced the ability of ovarian cancer cells to invade 3D collagen gels.


CONCLUSIONS
The data from the current study identify a novel regulatory mechanism for the control of WT1 expression and provide evidence for a functional role of WT1 protein in the control of cellular invasive activity.
Barbolina
Maria V
MV
Department of Chemical and Biological Engineering, Northwestern University, Chicago, Illinois, USA.
Adley
Brian P
BP
Shea
Lonnie D
LD
Stack
M Sharon
MS
D018262:Adenocarcinoma, Clear Cell / Q000235:genetics / Q000378:metabolism / Q000556:secondary*; D002288:Adenocarcinoma, Mucinous / Q000235:genetics / Q000378:metabolism / Q000556:secondary*; D015153:Blotting, Western; D018269:Carcinoma, Endometrioid / Q000235:genetics / Q000378:metabolism / Q000556:secondary*; D018797:Cell Cycle Proteins; D002465:Cell Movement; D024042:Collagen Type I / Q000378:metabolism; D024061:Collagen Type III / Q000378:metabolism; D018284:Cystadenocarcinoma, Serous / Q000235:genetics / Q000378:metabolism / Q000556:secondary*; D005260:Female; D005455:Fluorescent Antibody Technique; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007124:Immunoenzyme Techniques; D009361:Neoplasm Invasiveness; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D010051:Ovarian Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D000072260:RNA Splicing Factors; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D014407:Tumor Cells, Cultured; D014945:Wound Healing
D018797:Cell Cycle Proteins; D024042:Collagen Type I; D024061:Collagen Type III; D009687:Nuclear Proteins; D000072260:RNA Splicing Factors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C419554:WTAP protein, human