ISSN:1010-4283    

DOI:10.1159/000218055

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

To explore the role of sex hormone-binding globulin (SHBG) in the intracellular steroidal actions in human uterine cervical cancers, the expression of SHBG mRNA as a manifestation of intracellular SHBG expression was investigated using the competitive reverse transcription-polymerase chain reaction-Southern blot analysis. The expression of SHBG mRNA was detected in all cervical endometria and cancers analyzed. The levels of SHBG mRNA in cervical cancers were significantly lower (p < 0.01) than in the normal cervical endometrium. In cervical cancers, the levels of SHBG mRNA in cervical adeno-carcinomas were significantly higher (p < 0.01) than in kera-tinizing and small cell nonkeratinizing squamous cell carcinomas, and tended to be higher than in large cell nonkeratinizing squamous cell carcinomas. There was no difference in expression among the clinical stages of cervical cancers. These data suggest that human uterine cervical cancers, especially ad-enocarcinomas, might synthesize SHBG intracellularly, and might conserve the activity of SHBG-related steroidal mechanisms to some extent.

ISSN:1010-4283    

DOI:10.1159/000218010

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

The effects of the endocrine milieu on growth, invasion and metastasis, associated with neovascularization of endometrial cancer, the expression of plasminogen activator inhibitor 1 (PAI-1), and its mRNA in endometrial atypical hyperplasia and cancer, and normal endometria as controls were determined in premenopausal and postmenopausal women. In pre-menopausal women, the levels of PAI-1 and its mRNA in normal endometria were significantly higher than in endometrial atypical hyperplasia and cancer. On the other hand, in postmenopausal women, the results were reversed. There was no difference in the expression of PAI-1 and its mRNA in the various histological grades and clinical stages in endometrial cancers, while the expression of PAI-1 in other cancers increased during tumor progression. In our previous study, the expression of PAI-1 and its mRNA in well-differentiated endometrial cancer cell lines was dependent upon estrogen and progesterone. This might be partially related to the endocrine milieu, especially in endometrial atypical hyperplasia and well-differentiated endometrial cancer, which seems to be dependent on sex steroids. Therefore, endometrial cancer of any histological grade and clinical stage might maintain PAI-1 expression in both premenopausal and postmenopausal women, which may modulate, at least in part, growth, invasion and metastasis associated with neovascularization of endometrial cancer.

ISSN:1010-4283    

DOI:10.1159/000218011

出版商:S. Karger AG    

年代:1997

数据来源: Karger

ISSN:1010-4283    

DOI:10.1159/000317868

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

To improve the effectiveness of 4-hydroxyphenylretinamide (4-HPR), an analogue of retinoic acid used in chemoprevention and treatment of breast cancer, we investigated the effect of concomitant administration of 4-HPR (0.1, 1 µM) and tamoxifen (TAM, 0.1, 1 µM), or 4-HPR and interferon-β (IFN-β, 10, 100, 500 IU/ml) on the growth offour cell lines (MCF7, T47D, MDA-MB231 and BT20) characterized by a different steroid receptor profile. A high concentration of 4-HPR caused a significant inhibitory effect not only on the estrogen receptor-positive cell lines (MCF7 and T47D), but also on one (BT20) of the two estrogen receptor-negative cell lines. IFN-β displayed a dose-dependent inhibitory effect in all cell lines, but it was most evident in MCF7 cells. In all cell lines, the combination of 4-HPR (0.1 µM) and TAM (1 µM) or IFN- β (500 IU/ml) generally caused additive or synergistic effects. In particular, the finding that in estrogen receptor-negative MDA-MB231 cells 4-HPR (which at 1 µM was singly ineffective) in combination with TAM at 1 µM or any concentration of IFN- β produced a synergistic effect suggests that the compound could act through a pathway independent of specific receptors for retinoids. Our results indicate that intrinsic characteristics of cells can influence responsiveness to 4-HPR, TAM and IFN- β, singly or in association, ever within cell lines with similar steroid receptor profiles. Thus, more attention should be payed to the biological characteristics of the single tumor in order to help choose the best combination of drugs to

ISSN:1010-4283    

DOI:10.1159/000218012

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Human hepatocarcinoma HepG2 cells are known to be insensitive to tumor necrosis factor (TNF) cytotoxicity. In this report, preliminary washing of HepG2 cells with serum-free medium to remove endogenous and exogenous α-fetoprotein (AFP) from the cultivation medium transfers cells from the TNF-resistant to the TNF-sensitive state without addition of any transcriptional inhibitors. HepG2 cells sensitized to by washing again became TNF-resistant after their treatment with exogenous AFP. Protective AFP activity against TNF-induced cytotoxicity directly depends on the AFP/TNF concentration ratio, demonstrating biphasic AFP activity. Our data show that 0.2 mg/ml of AFP acts synergistically to enhance cytotoxicity of suboptimal TNF doses. In contrast, the same AFP dose significantly attenuates the cytotoxicity of high TNF doses. It is concluded that AFP can function as a protective factor against TNF cytotoxicity in human hepatoma cells. These observations suggest that AFP secretion by certain tumor cells allows a highly flexible regulation of TNF cytotoxicity, dependent on the amount of endogenous AFP

ISSN:1010-4283    

DOI:10.1159/000218013

出版商:S. Karger AG    

年代:1997

数据来源: Karger

ISSN:1010-4283    

DOI:10.1159/000317869

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

We studied the effect of tumoral microenvironments on metastatic phenotypes. Therefore, murine mammary adenocarcinoma cells cultured in vivo in diffusion chambers (DC) were implanted intraperitoneally in BALB/c mice. The behavior of DC-cultured cells was compared with that of cells obtained from tumors growing subcutaneously or intraperitoneally and from primary cultures in vitro of the former. DC-cultured and control cells were inoculated into normal mice to evaluate their tumorigenicity and metastasizing ability. We found that DC-cultured cells were less tumorigenic and metastatic both in spontaneous and in experimental metastasis assays. The host reponse to tumor progression resulted in an early leukocytosis, probably due to the overproduction of a hematopoietic factor by the tumor cells. Finally, it was found that DC-cultured cells produced lower levels of urokinase-type plasmino-gen activator activity, while no differences were found in the metalloproteinase production compared to cells obtained from a tumor growing subcutaneously.

ISSN:1010-4283    

DOI:10.1159/000218014

出版商:S. Karger AG    

年代:1997

数据来源: Karger

ISSN:1010-4283    

DOI:10.1159/000317870

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

We describe a new, simple and reliable semiautomated strategy for quantifying mRNA from archival specimens by using oligo(dT)25 paramagnetic beads and the reverse-transcriptase polymerase chain reaction (PCR) coupled with quantitative digital image analysis (Q-DIA). To evaluate the experimental conditions, we examined thymidylate synthase (TS) gene expression in mRNA isolated from both flash-frozen and formalin-fixed paraffin-embedded human biopsy samples using biopsy material obtained from 2 patients prior to chemotherapy with 5-fluorouracil. Following the electrophoretic separation of the PCR products through a 20% polyacrylamide gel, quantitation of the perimeters of the silver-nitrate-stained PCR products will be done by Q-DIA using a video frame-grabber board attached to a CCD camera using Image-Pro+TM software. Validation of this approach will involve a comparison of the observed gene expression levels to TS protein levels obtained by tissue homogenization assays of TS, tetrahydrofo-late, 5, 10-methylenetetrahydrofolate, 2′-deoxyuridine-5′-monophosphate and 5-fluoro-2′-deoxyuridylate (FdUMP), by established [3H]FdUMP li-gand-binding assays. The novelty of this method is that it offers a low-cost means whereby Q-DIA is performed directly from the gel to rapidly and accurately determine the level of TS gene expression, which is standardized against the β-actin housekeeping gene. In the protocol described herein, gene expression studies can be done quickly and without the use of radioactive substances in both normal clinical samples shock frozen at the time of surgical excision and in formalin-fixed paraffin-embedded archival samples, which are commonly available in all hospital pathology departments. To demonstrate the utility of this method, mRNA was extracted from both nonpathological and tumor biopsies originating from both types of material from the same patients. TS gene expression in the flash-frozen and archival materials was compared to the level of TS intracellular enzyme activity in the same samples and a correlation of 89 and 80% between the shock-frozen and archival material relative to TS intracellular enzyme activity levels was observed. These findings suggest that routine semiautomated quantitative analysis of rare mRNA transcripts, e.g. TS, from archival material can be applied for retrospective s

ISSN:1010-4283    

DOI:10.1159/000218015

出版商:S. Karger AG    

年代:1997

数据来源: Karger