Objectives: Adipose tissue contains a population of multipotent mesenchymal stromal cells (ASC) which exhibit tumor tropism, similar to bone marrow derived mesenchymal stem cells (MSC). Excess visceral adipose tissue increases the risk of ovarian cancer. The omentum is a prominent site for ovarian cancer metastasis. We hypothesize that the omentum serves as a source of ASC which promote ovarian cancer progression.

Materials and Methods: ASC were isolated from the omentum (O-ASCs) of three patients with ovarian cancer. O-ASC1 was isolated from a patient with synchronous adenocarcinoma of endometrial and ovarian cancer without peritoneal metastasis; and O-ASC4 and O-ASC5 were isolated from patients with peritoneally disseminated serous ovarian cancer. Gene expression array profiling was performed with using Nimblegen arrays (Roche NimbleGen, Inc., Madison, WI). The impact of stromal cells on proliferation and chemoresistane and radio-protection of ovarian cancer cells was tested with co-culture assays using luciferase-labeled human ovarian cancer cell lines. Transwell migration assays were performed with conditioned media from O-ASC and control cell lines. To evaluate of O-ASCs tumor tropism in-vivo experiment was performed.

Results: Human O-ASCs were detected engrafted within the stroma of human ovarian cancer xengrafts. O-ASC significantly promoted in-vitro proliferation and migration of ovarian cancer cell lines OVCA 429, OVCA 433, A2780. Co-culture of ovarian cancer cells with O-ASCs increased resistance to chemotherapeutic drugs and radiation. Gene expression array analysis revealed significant differences in expression profiles for group of 415 genes in sub-populations of O-ASCs.

Conclusions: Adipose stem cells derived from human omentum promoted the proliferation, migration, chemoresistance and radioresistance of ovarian cancers. Clinical isolates demonstrate heterogenous effects in- vitro. Future studies will determine if tumor promoting effects of O-ASC can be predicted on the basis of clinical or disease related characteristics.

Citation Format: Aleksandra Nowicka, Travis Solley, Frank C. Marini, Hadley J. Sharp, Russell R. Broaddus, Kolonin G. Mikhail, Samuel C. Mok, Wendy A. Woodward, Karen H. Lu, Ann H. Klopp. Human omental-derived adipose stem cells: Modulator of ovarian cancer proliferation, migration and chemoresistance. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: From Concept to Clinic; Sep 18-21, 2013; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2013;19(19 Suppl):Abstract nr B73.