GROWTH-FACTOR EXPRESSION BY HUMAN OVIDUCT AND BUFFALO RAT-LIVER COCULTURE CELLS

Objective: To characterize growth factor gene expression by passaged c oculture cell lines demonstrated to enhance in vitro pre-embryo growth . Design: Ribonucleic acids isolated from the isthmus, ampullary, and fimbriae portions of the human oviduct, and from buffalo rat liver cel l monolayers were subjected to Northern analysis using probes for grow th factors. Setting: Academic tertiary care hospital. Patient(s): Two reproductive age women undergoing a hysterectomy and bilateral salping ectomy for benign gynecologic conditions consented to experimental use of their oviducts. Intervention(s): Cell cultures were established fr om fresh human oviduct segments and commercially purchased buffalo rat liver cells. After two passages, total RNA was isolated from these co nfluent monolayers, fractionated on denaturing agarose gels, transferr ed to nylon membranes, and analyzed by Northern hybridization using co mplementary DNAs from epidermal growth factor (EGF), stem cell factor, also known as Kit-ligand, colony-stimulating factor-1 (CSF), leukemia inhibitory factor, and interleukin-6 (IL-6). Radioactively labeled pr obes were prepared by in vitro transcription or by 5' end labeling. Af ter hybridization, blots were washed at increasing strigencies to remo ve nonspecifically bound radioactivity and subjected to autoradiograph y. Result(s): Human oviduct coculture cells express EGF (kit-ligand), CSF, leukemia inhibitory factor, and IL-6. Buffalo rat liver cells con tain the messenger RNA transcripts for kit-ligand and CSF. Conclusion( s): Human oviduct and buffalo rat liver coculture cells express specif ic growth factors. These results support the theory that coculture sys tems may enhance pre-embryo growth via the production of embryotrophic factors. The identification of these ligands may provide the rational e for selecting specific growth factors for media supplementation as w ell as contribute to our understanding of the general mechanisms invol ved in regulating early embryonic growth and development. (C) 1997 by American Society for Reproductive Medicine.