Site:  Oregon Health & Science University

Principal Investigator:  Richard L. Stouffer, PhD

Co-Investigators: Mary B. Zelinski, PhD; David M. Lee, MD

Rationale

While cancer eradication is the immediate and paramount goal for patients and their physicians, the increased chance of survival has led to efforts to ensure or restore the quality of life after cancer.  Data indicates that fertility after treatment is a major concern of young female cancer patients; yet many women state that their concerns are not adequately addressed. Unlike young men who have a clinically proven option in sperm cryopreservation, the methods for fertility preservation in young women and girls remain experimental.  This is due in part to the limited accessibility of the ovaries and difficulties in manipulating the larger oocyte. 

A primary goal of the new oncofertility researcher is to merge the principles of tissue engineering and biomaterial science with ovarian biology to develop novel fertility preservation options for girls and young women who must undergo treatments that threaten their fertility. One strategy to prevent oocyte exposure to the toxic effects of therapy is to remove eggs or ovarian tissue for cryopreservation prior to therapy.  Once treatment is complete, the goal is to either transplant thawed ovarian tissue or isolate the follicles from the tissue, mature them in vitro, and use them for in vitro fertilization.

In this project, translational studies of these techniques are being performed in nonhuman primates because they offer an easily manipulated, available system for determining if concepts originating from traditional research animals (mouse) are relevant to reproductive processes in primates, including humans.  In addition, the nonhuman primate provides a means for assessing ethical and practical issues that cannot be studied in women or children. 

The objectives of this project are to:

  • Validate a matrix scaffold that supports the 3-D architecture of the primate follicle and permits the coordinated development of the follicle wall and oocyte in vitro
  • Evaluate the role of gonadotropic hormones and growth factors in promoting the growth and maturation of primate follicles and their enclosed oocytes in vitro
  • Optimize conditions for autotransplantation of ovarian cortex to readily accessible sites for coordinated follicle growth and oocyte maturation in vivo in primates
  • Assess the fertilization and embryonic potential of primate oocytes derived from in vitro matured follicles and autotransplanted ovarian cortex

Key Experiments

  • Mechanically isolate immature follicles from rhesus ovarian tissue and culture in various concentrations of alginate and alginate plus components of the ECM to determine the optimal scaffold for survival and growth of these follicles
  • Define the extent and time course of neovascularization of fresh and cryopreserved ovarian tissue autografted to the arm and abdomen and determine if long term endocrine function is maintained post-transplantation
  • Using in vitro fertilization, evaluate the reproductive potential of in vitro matured oocytes or oocytes retrieved from cortically transplanted tissue

Consortium Support and Impact

The successful execution of this project requires close collaboration with other members of the Oncofertility Consortium®.  Specifically, this project will provide fresh ovarian cortical biopsies to cryobiologists for the development of effective methods for follicle cryopreservation.  All advances in the nonhuman primate model will be rapidly translated to efforts using human ovarian tissue.  The Biomaterials Core will provide alginate hydrogel matrices to support 3-D follicle culture, while the National Physicians Cooperative will provide a centralized medical network that will allow researchers at various sites and programs to quickly and easily access data and findings from this and other projects.  Education of physicians and the public, and training of oncofertility specialists will be key elements to communicate the latest developments in primate follicle biology and their implications for women facing cancer.

Publications

Xu J, Lawson MS, Yeoman RR, Pau KY, Barrett SL, Zelinski MB, Stouffer RL. Secondary follicle growth and oocyte maturation during encapsulated three-dimensional culture in rhesus monkeys: effects of gonadotrophins, oxygen and fetuin. Hum Reprod. 2011 Feb 28.

Xu J, Bernuci MP, Lawson MS, Yeoman RR, Fisher TE, Zelinski MB, Stouffer RL. Survival, growth, and maturation of secondary follicles from prepubertal, young and older adult, rhesus monkeys during encapsulated three-dimensional (3D) culture: effects of gonadotropins and insulin. Reproduction, Aug. Epub 2010. PMID  20729335 

 

This research was supported by the Oncofertility Consortium®, funded by the National Institutes of Health through the NIH Roadmap for Medical Research, Grant UL1DE19587 and RL1HD058294.