Circulating IGF-binding protein 7 (IGFBP7) levels are elevated in patients with endometriosis or undergoing diabetic hemodialysis.

BACKGROUND: Insulin-like growth factor-binding protein-7 (IGFBP7) is a secretory protein with a molecular mass of approximately 30 kDa. It is abundantly expressed in the uterine endometrium during the secretory phase of the menstrual cycle. Decreased IGFBP7 expression has been observed in some cancers and leiomyomata. METHODS: To determine whether serum IGFBP7 levels reflect changes in uterine IGFBP7 expression in humans during the menstrual cycle, and to examine whether serum IGFBP7 levels are altered in patients with various disorders, we developed a novel, dual-antibody sandwich enzyme-linked immunosorbent assay (ELISA). Firstly, concentrations of IGFBP7 released into the medium were determined in cultured endometrial stromal and glandular cells. Blood samples were collected from women who had normal menstrual cycles and who had been diagnosed with endometriosis. Serum from hemodialysis patients and gastrointestinal cancers was also used to determine the IGFBP7 levels. RESULTS: Using this new ELISA, we demonstrated that cultured uterine cells secrete IGFBP7 into the medium. Patients with endometriosis and those with type II diabetes mellitus undergoing hemodialysis had significantly higher serum concentrations of IGFBP7 than the relevant control subjects. There were no differences in serum IGFBP7 levels in women at different stages of the menstrual cycle. Furthermore, serum IGFBP7 levels in patients with colorectal, esophageal, or endometrial cancer were not different than normal healthy subjects. CONCLUSION: Our observations suggest that IGFBP7 is associated with the pathophysiology of endometriosis and diabetes mellitus, and that serum IGFBP7 levels do not reflect enhanced uterine expression of IGFBP7 mRNA during the menstrual cycle.

Hypoxia-inducible factor-1 transactivates transforming growth factor-beta3 in trophoblast.

Hypoxia occurs during the development of placenta in the first trimester and is implicated in trophoblast differentiation. Intervillous blood flow increases after 10 wk of gestation and results in exposure of trophoblast cells to oxygen. Before this time, low oxygen appears to prevent trophoblast differentiation toward an invasive phenotype. The oxygen-regulated early events of trophoblast differentiation are mediated by TGF-beta3. TGF-beta3 plays a vital role in trophoblast differentiation, and its overexpression can be found in preeclamptic placenta. We sought to determine the mechanism of TGF-beta3 expression through hypoxia-inducible factor (HIF)-1. We show that HIF-1alpha and TGF-beta3 are overexpressed in preeclamptic placenta. Hypoxia not only transactivates the TGF-beta3 promoter activity but also enhances endogenous TGF-beta3 expression. Using the TGF-beta3 promoter deletion mutants, we show that the region between -90 and -60, which contains a putative HIF-1 consensus motif, is crucial for HIF-1-mediated transactivation. Electrophoretic mobility shift assays show that HIF-1 binds to the oligonucleotide containing the HIF-1 motif. Also, introduction of an antisense oligonucleotide for HIF-1 diminishes TGF-beta3 expression during hypoxia, indicating that the up-regulation of TGF-beta3 by hypoxia is mediated through HIF-1. Our results provide evidence that regulation of TGF-beta3 promoter activity by HIF-1 represents a mechanism for trophoblast differentiation during hypoxia.

Establishment of a HPV and p53-mutation-negative human cell line (CA) derived from a squamous carcinoma of the uterine cervix.

OBJECTIVE: Well-characterized human cancer cell lines are important research resources for studying cancer cell biology, as well as for developing new strategies against cancer cell growth and progression. We present a new cell line, CA, established from an invasive non-keratinizing squamous cell carcinoma of the uterine cervix in 36-year-old patient. METHODS: We measured the doubling time of CA cells. To investigate the tumorigenicity of CA, cells were inoculated subcutaneously into the back of nude mice. Several tumor markers were analyzed using culture media by EIA. PCR-based analyses were performed to examine the human papillomavirus (HPV) status and telomerase activity. CA was also screened for p53 mutation using the sequencing technique. RESULTS: The cells show rapid growth in culture with a doubling time of 14.3 h and high migration activity. Monolayer-cultured cells were polygonal, showing a pavement-like arrangement and a tendency to pile up without contact inhibition. Subcutaneous transplantation of the CA cells into nude mice formed solid tumors that were histologically diagnosed as squamous cell carcinoma, whereas no metastasis was observed. Cultured CA cells produced SCC, CEA, TPA, CA125 and SLX. Genetic and molecular analyses revealed high telomerase activity and the absence of HPV DNA. No p53 mutation was observed in this cell line. CONCLUSION: These properties suggest that CA is an aggressive cervical carcinoma cell line and may serve as a useful experimental model for studying HPV role in cervical carcinogenesis.