Hypoxia occurs during the development of the placenta in the first trimester and correlates with both trophoblast differentiation and the induction of telomerase activity through hTERT expression. We sought to determine the mechanism of regulation of hTERT expression during hypoxia. We show that hypoxia-inducible factor 1␣ (HIF-1␣) and hTERT expression in the human placenta decrease with gestational age and that these are overexpressed in preeclamptic placenta, a major complication of pregnancy. Hypoxia not only transactivates the hTERT promoter activity but also enhances endogenous hTERT expression. The hTERT promoter region between ؊165 and ؉51 contains two HIF-1 consensus motifs, and in vitro reporter assays show that these are essential for hTERT transactivation by HIF-1. Introduction of an antisense oligonucleotide for HIF-1 diminishes hTERT expression during hypoxia, indicating that upregulation of hTERT by hypoxia is directly mediated through HIF-1. Our results provide persuasive evidence that the regulation of hTERT promoter activity by HIF-1 represents a mechanism for trophoblast growth during hypoxia and suggests that this may be a generalized response to hypoxia in various human disorders including resistance to cancer therapeutics by upregulating telomerase.

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.

BACKGROUND The human matrix metalloproteinase (MMP)‐26, also called matrilysin‐2 or endometase, has been isolated as a matrilysin (MMP‐7) homolog. Matrix metalloproteinase‐26 was expressed in tissue samples from the placenta and endometrial tumors and its expression may be related to the development of endometrial carcinomas. METHODS Total RNAs were isolated from 5 endometrial carcinoma cell lines, 36 normal endometrial tissue samples, 4 hyperplasia tissue samples, and from 24 endometrial carcinoma tissue samples. Reverse transcription‐polymerase chain reation (RT‐PCR) was performed to detect MMP‐26 mRNA expression. To identify MMP‐26 mRNA localization and protein expression, we performed in situ RT‐PCR and immunohistochemistry, respectively. RESULTS Reverse transcription‐polymerase chain reaction analysis revealed that MMP‐26 mRNA was expressed in 24 of 36 normal human endometrial tissue samples. However, MMP‐26 mRNA expression was not detected in endometrial carcinoma cell lines nor in endometrial carcinoma tissue samples except for one case. Western blot analysis showed similar results. In situ RT‐PCR analysis revealed that MMP‐26 expression was localized in the epithelial glandular cells but faint expression was observed in the stromal cells. Subsequently, we separated endometrial tissues into epithelial glandular and stromal cells. Using RT‐PCR, the purified epithelial glandular cells exhibited MMP‐26 mRNA expression but the purified stromal cells did not. Immunohistochemical analyses revealed that MMP‐26 protein expression is also limited to endometrial epithelial glandular cells but not to cancer cells. Therefore, MMP‐26 expression is limited to normal epithelial glandular cells. CONCLUSIONS We found a significant difference in MMP‐26 expression in normal and malignant endometrial tissue samples, although its function is still unknown. These data suggest that MMP‐26 may be a candidate for a new tumor marker for endometrial carcinomas. Cancer 2003;97:79–89. © 2003 American Cancer Society. DOI 10.1002/cncr.11030

No abstract

Bartter's syndrome is a rare renal disorder, and since there are few case reports of Bartter's syndrome complicating pregnancy are few, the changes of electrolytes and hormonal metabolism during pregnancy are unknown. We describe and discuss the course of pregnancy complicated with Bartter's syndrome.

No abstract

We present a new cell line, EJ established from an invasive endometrioid adenocarcinoma of the uterine corpus in a 56-year-old patient. The cells show rapid growth in culture with a doubling time of 16 h and high migration activity. Monolayer-cultured cells were polygonal in shape showing a tendency to pile up without contact inhibition. Subcutaneous transplantation of the EJ cells into nude mice formed solid tumors that were histologically diagnosed as adenocarcinoma, whereas no metastasis was observed. Cultured EJ cells produced tissue polypeptide antigen (IPA). Genetic and molecular analyses revealed high telomerase activity but not estrogen receptor alpha expression. Using the DNA sequencing technique, we have screened EJ cells for p53 mutation in exon 5 to 8 but no mutation of p53 was observed. This cell line appears to represent the development of a more malignant clone with divergent receptor function and growth behavior, and provides us with an interesting new tool for the study of tumorigenesis in the human endometrium.

No abstract