This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ricken*, A. Articles by Farookhi, R. Search for Related Content PubMed PubMed Citation Articles by Ricken*, A. Articles by Farookhi, R.

Wnt Signaling in the Ovary: Identification and Compartmentalized Expression of wnt-2, wnt-2b, and Frizzled-4 mRNAs

Department of Obstetrics and Gynecology (A.R., P.L., M.K., R.F.) and Department of Physiology (R.F.), McGill University, Montréal, Québec, Canada H3A 1A1

Address all correspondence and requests for reprints to: Riaz Farookhi, F3.44 Royal Victoria Hospital, 687 Pine Avenue West, Montréal, Québec, Canada H3A 1A1. E-mail: . Riaz.Farookhi{at}MUHC.McGill.ca

Ovarian cadherins, in addition to acting as structural (adhesion) molecules, also function as modulators of gene activity. The dual role of ß-catenin as an intracellular component of the cadherin adhesion complex and as a transcription factor provides a possible explanation for these cadherin effects. Because the transcriptional activity of ß-catenin is dependent on activation by the wnt signaling cascade, we examined whether components of this cascade are expressed in the rat ovary.

Using RT-PCR with degenerate primers on RNA from ovaries of hormone-stimulated immature rats, we identified transcripts for wnt-2 and wnt-2b. RT-PCR and in situ hybridization (ISH) demonstrated that granulosa cells express wnt-2 mRNA. Because the sequence for rat wnt-2b has not been reported, we obtained additional sequence by screening a rat ovarian cDNA library. RT-PCR analysis, using primers designed from this wnt-2b cDNA sequence, failed to detect transcripts in the ovarian follicular compartment (granulosa and oocyte). ISH revealed that the ovarian surface epithelium expresses wnt-2b mRNA. Using a similar degenerate RT-PCR approach, we detected expression of a putative wnt receptor, frizzled-4 (fzd-4), and a cytoplasmic component of the wnt signaling cascade, disheveled-2 (dsh-2), in the rat ovary. Further analyses using both RT-PCR and ISH indicated that granulosa cells express fzd-4 mRNA.

The expression of wnt-2b transcripts in rat ovarian surface epithelium prompted us to examine whether the homologous gene is expressed in human ovarian cancer cell lines. RT-PCR, using degenerate and specific primers for wnts, on RNA from five ovarian cancer cell lines confirmed the expression of transcripts for wnt-2b. Two additional wnt transcripts (wnt-5a and wnt-11) were detected in the cancer cell lines and in the rat ovary.

These results demonstrate that transcripts corresponding to components of the wnt signaling cascade are expressed in the immature rat ovary. The localization of these transcripts in specific ovarian compartments suggests that this signal transduction pathway may be involved in follicular development and ovarian function. Furthermore, because wnts have been implicated in the oncogenic transformation of epithelial cells, our results raise the possibility that aberrant wnt expression may be involved in ovarian tumorigenesis in humans.

This article has been cited by other articles:

				M. A. Edson, A. K. Nagaraja, and M. M. Matzuk The Mammalian Ovary from Genesis to Revelation Endocr. Rev., October 1, 2009; 30(6): 624 - 712. [Abstract] [Full Text] [PDF]

				E. Nilsson, G. Dole, and M. K Skinner Neurotrophin NT3 promotes ovarian primordial to primary follicle transition Reproduction, October 1, 2009; 138(4): 697 - 707. [Abstract] [Full Text] [PDF]

				N. Golestaneh, E. Beauchamp, S. Fallen, M. Kokkinaki, A. Uren, and M. Dym Wnt signaling promotes proliferation and stemness regulation of spermatogonial stem/progenitor cells Reproduction, July 1, 2009; 138(1): 151 - 162. [Abstract] [Full Text] [PDF]

				H.-X. Wang, F. R. Tekpetey, and G. M. Kidder Identification of WNT/{beta}-CATENIN signaling pathway components in human cumulus cells Mol. Hum. Reprod., January 1, 2009; 15(1): 11 - 17. [Abstract] [Full Text] [PDF]

				P. A. Fowler, D. R. Abramovich, N. E. Haites, P. Cash, N. P. Groome, A. Al-Qahtani, T. J. Murray, and R. G. Lea Human fetal testis Leydig cell disruption by exposure to the pesticide dieldrin at low concentrations Hum. Reprod., November 1, 2007; 22(11): 2919 - 2927. [Abstract] [Full Text] [PDF]

				C. Stocco, C. Telleria, and G. Gibori The Molecular Control of Corpus Luteum Formation, Function, and Regression Endocr. Rev., February 1, 2007; 28(1): 117 - 149. [Abstract] [Full Text] [PDF]

				D. Boerboom, L. D. White, S. Dalle, J. Courty, and J. S. Richards Dominant-Stable {beta}-Catenin Expression Causes Cell Fate Alterations and Wnt Signaling Antagonist Expression in a Murine Granulosa Cell Tumor Model Cancer Res., February 15, 2006; 66(4): 1964 - 1973. [Abstract] [Full Text] [PDF]

				A. Steg, W. Wang, C. Blanquicett, J. M. Grunda, I. A. Eltoum, K. Wang, D. J. Buchsbaum, S. M. Vickers, S. Russo, R. B. Diasio, et al. Multiple Gene Expression Analyses in Paraffin-Embedded Tissues by TaqMan Low-Density Array: Application to Hedgehog and Wnt Pathway Analysis in Ovarian Endometrioid Adenocarcinoma J. Mol. Diagn., February 1, 2006; 8(1): 76 - 83. [Abstract] [Full Text] [PDF]

				D. Boerboom, M. Paquet, M. Hsieh, J. Liu, S. P. Jamin, R. R. Behringer, J. Sirois, M. M. Taketo, and J. S. Richards Misregulated Wnt/{beta}-Catenin Signaling Leads to Ovarian Granulosa Cell Tumor Development Cancer Res., October 15, 2005; 65(20): 9206 - 9215. [Abstract] [Full Text] [PDF]

				E. Jansen, J. S. E. Laven, H. B. R. Dommerholt, J. Polman, C. van Rijt, C. van den Hurk, J. Westland, S. Mosselman, and B. C. J. M. Fauser Abnormal Gene Expression Profiles in Human Ovaries from Polycystic Ovary Syndrome Patients Mol. Endocrinol., December 1, 2004; 18(12): 3050 - 3063. [Abstract] [Full Text] [PDF]

				M. Hsieh, S. M. Mulders, R. R. Friis, A. Dharmarajan, and J. S. Richards Expression and Localization of Secreted Frizzled-Related Protein-4 in the Rodent Ovary: Evidence for Selective Up-Regulation in Luteinized Granulosa Cells Endocrinology, October 1, 2003; 144(10): 4597 - 4606. [Abstract] [Full Text] [PDF]