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Biomedical subjects

Kimberly K Leslie

Publications and source records attributed to Kimberly K Leslie.

16 recordsLinked to original sources
PubMed2006

Gestational trophoblastic diseases: 1. Pathophysiology of hyperglycosylated hCG.

OBJECTIVE: Hyperglycosylated hCG (hCG-H) is a glycosylation variant of hCG produced by cytotrophoblast cells at implantation of pregnancy and in choriocarcinoma. We investigated the biological function of hCG-H in invasion in vitro and in vivo and the use of hCG-H antibodies in blocking tumorigenesis and cancer growth in vivo. METHODS AND RESULTS: hCG-H accounts for 43% to 100% of total hCG immunoreactivity in the culture fluid of choriocarcinoma cell lines and 100% in primary cultures of pregnancy cytotrophoblast cells. We investigated the action of hCG and hCG-H on isolated cytotrophoblast cell primary cultures and on 3 different lines of choriocarcinoma cells cultured on Matrigel basement membrane inserts (culture models for assessing tumor invasion). The addition of hCG-H to medium significantly promoted invasion of membranes with both pregnancy and cancer cell line sources, while regular hCG had no significant effect. JEG-3 human choriocarcinoma cells were transplanted subcutaneously into athymic nude mice. Tumors rapidly formed. B152, mouse monoclonal antibody against hCG-H, and non-specific mouse IgG (control) were administered twice weekly once tumors were clearly visible. While a correlation between time and growth was observed with the control group (r(2)=0.97), no correlation was observed with the B152-treated mice (r(2)=0.15). B152 blocked tumor growth (t test, IgG vs. B152, P=0.003). In a second experiment, antibody B152 or IgG was administered to mice at the time of choriocarcinoma transplantation. B152 significantly inhibited tumorigenesis (t test P=0.0071). CONCLUSIONS: hCG-H is a critical promoter in human cytotrophoblast and human choriocarcinoma cell invasion in vivo and in vitro, promoting tumor growth and invasion through an autocrine mechanism. hCG-H is a signal for choriocarcinoma cell invasion, making it a biological tumor marker. Antibodies against hCG-H block tumor formation and growth. Human or humanized antibodies against hCG-H may be useful in treating and managing choriocarcinoma and other gestational trophoblastic malignancies.

Animals↗
PubMed2005

Gene regulation profiles by progesterone and dexamethasone in human endometrial cancer Ishikawa H cells.

OBJECTIVE: Progesterone and glucocorticoids such as dexamethasone mediate distinct biological functions, yet they bind to receptors that recognize the same consensus DNA response element. In breast cancer, progestins are associated with the incidence and progression of tumors, whereas glucocorticoids are growth-suppressive in mammary cancer cells; the differential effects of these two steroids are less well understood in the hormone-dependent disease cancer of the uterine endometrium. We set out to identify genes that are regulated by progesterone through progesterone receptors and dexamethasone through glucocorticoid receptors in a well-differentiated human endometrial cancer cell line. METHODS: PR- and GR-positive Ishikawa H endometrial cancer cells were treated with vehicle, dexamethasone (100 nM) or progesterone (100 nM) for 2 h, 6 h, 12 h and 24 h, and RNA was isolated. Affymetrix microarrays were performed using the human HG-U133A chip, querying the expression of 22,000 genes. Expression of genes of particular interest was confirmed by real-time RT-PCR. RESULTS: Expression analysis demonstrated that dexamethasone and progesterone regulate overlapping but distinct sets of genes and presumably exert many similar but also unique biological effects. Using real-time RT-PCR, we confirmed three particular genes of interest: the transcript for cysteine 1 (legumain), a gene associated with metastasis, that is strongly downregulated by progesterone, upstream c-fos relating transcription factor-2 (USF-2), an anti-proliferative factor that is induced by both progesterone and dexamethasone and N-cadherin, a cellular adhesion molecule downregulated by dexamethasone. CONCLUSION: These studies provide new insight into the effects of progesterone and dexamethasone in endometrial cancer cells and provide an extensive list of regulated pathways which can be assessed in the future as biomarkers and molecular targets for new therapies. Taken together, our findings indicate that progesterone and dexamethasone are primarily growth inhibitors in Ishikawa H endometrial cancer cells.

Antigens, CD↗
PubMed2005

A potential synergistic anticancer effect of paclitaxel and amifostine on endometrial cancer.

Although paclitaxel is one of the most effective chemotherapeutic agents, its usefulness is still limited in advanced and recurrent endometrial cancer. Amifostine protection of normal tissues against the side effects of chemotherapeutic agents has been clinically proven in cancer patients; however, its application in endometrial cancer has not been fully evaluated. We have investigated the use of paclitaxel and amifostine in controlling the growth of poorly differentiated endometrial cancer cells, Hec50co, in vitro and in vivo. Our studies show that amifostine had direct anticancer effects on endometrial cancer cells in vitro by arresting the cell cycle at the G1 phase and inducing apoptosis. Amifostine also inhibited s.c. tumor growth in athymic mice. Paclitaxel IC50 value was reduced from 14 to 2 nmol/L with pretreatment of a single dose of 178 micromol/L of amifostine for 72 hours. Amifostine also synergized with paclitaxel in the arrest of the cell cycle at the G2-M phase and in the induction of apoptosis. This two-drug regimen inhibited s.c. tumor growth as well as improved mouse survival significantly more than paclitaxel alone. Amifostine also significantly improved paclitaxel-induced cytotoxic effects on peripheral blood profiles. Our studies show that amifostine has direct anticancer effects on endometrial cancer. Our data have also shown a potential anticancer synergy between amifostine and paclitaxel in vitro and in vivo, whereas amifostine maintained a protective role in peripheral blood profiles. The dual specificity of amifostine action should be further investigated.

Amifostine↗
PubMed2005

Chemotherapeutic drugs in pregnancy.

Chemotherapy may be indicated for the treatment of cancer during pregnancy. The decision to use chemotherapy significantly impacts the pregnancy, and in turn the pregnancy may affect the treatment options available to patients with cancer. This review provides information about the effects of chemotherapeutic agents in pregnancy, taking into account both the mother and the fetus. For convenience, the agents are divided into categories based upon class and mechanism of action. These include alkylating agents, antimetabolites, nucleoside analogs, topoisomerase I inhibitors, topisomerase II inhibitors, vinca alkaloids, taxanes, and biologics such as signaling and growth factor blocking agents.

Antineoplastic Agents↗
PubMed2005

Breast cancer and pregnancy.

This article addresses a challenging diagnostic and treatment dilemma encountered in the care of pregnant women-breast cancer. The treatment of a breast cancer is significantly affected by an ongoing pregnancy and may result in an increased risk for a poor outcome in the mother. The definition, incidence, mechanism, diagnosis, and treatment of breast cancer associated with pregnancy and the normal physiologic and endocrine changes in the breast during pregnancy that contribute to the difficulty encountered by practitioners in diagnosing and treating the disorder are reviewed. The risks associated with pregnancy after breast cancer treatment and the effect of pregnancy on lifetime risk for breast cancer in the general population and for women with mutations in BRCA1 and BRCA2 are also discussed.

Breast↗
PubMed2005

Progesterone receptor isoform identification and subcellular localization in endometrial cancer.

OBJECTIVE: These studies were undertaken to characterize the subcellular localization of the two major isoforms of progesterone receptors (PR), PRA and PRB, in endometrial cancer. METHODS: Immunohistochemistry, immunoprecipitation, and confocal microscopy were performed using Hec50co and KLE endometrial cancer cell models expressing PRA or PRB as a consequence of transduction. The location of PRB compared to PRA was determined, and antibodies were tested for specificity with respect to PR isoform recognition. Immunohistochemical analyses of PR expression and subcellular compartmentalization were also performed on 20 formalin-fixed endometrial cancer tumors. RESULTS: Morphological and biochemical evaluations demonstrated that PRA is localized to the nucleus, even in the absence of progesterone. In contrast, a large proportion of PRB is cytoplasmic in the absence of ligand, but is rapidly translocated to the nucleus in the presence of progesterone. The differential distribution of PRA and PRB proved to be a hallmark of malignant and nonmalignant epithelia in 20 samples of archival endometrial tissue from women with the pre-operative diagnosis of endometrial cancer. All endometrial cancer specimens demonstrated cytoplasmic PRB in 50% or more of the cells, and five of the seven tumors that were moderately to poorly differentiated demonstrated no PRB staining in the nuclei. Nuclear PRB was significantly associated with increasing tumor differentiation (P = 0.031). CONCLUSION: In the absence of ligand, PRA is nuclear and PRB is largely cytoplasmic. This suggests that PRA may exert ligand-independent nuclear effects, while PRB may have nongenomic cytoplasmic actions in endometrial cancer cells.

Antibodies, Monoclonal↗
PubMed2005

Obstetric forceps training using visual feedback and the isometric strength testing unit.

OBJECTIVE: This is a descriptive study that tested the maximum traction residents could apply to forceps during simulations. Visual feedback was then used to reinforce an optimal range of traction, and the ability of residents to reproduce this pull when blinded was assessed. METHODS: Fifty-five residents participated in 6 pulling exercises using an isometric strength testing unit with a real-time computer printout of the force applied. Maximum traction was determined for male and female residents in standing and sitting positions. Visual feedback was then used to estimate whether residents could be trained to reproduce an optimal force range of 30-45 pounds. Data were analyzed using a repeated measures analysis of variance. RESULTS: When asked to produce a maximum pull, male residents could generate significantly more force than females in the standing and sitting positions (P < .001). In general, all residents of both sexes generated more traction in the sitting position than in the standing position. The mean maximum traction produced by men in the standing and sitting positions was 69.5 and 85.8 pounds, respectively. For women, the mean maximum force generated was 45.5 pounds in the standing position and 61.3 pounds in the sitting position. Residents could easily reproduce an appropriate force in the short term after training by computer-assisted visual feedback. CONCLUSION: Motor learning tasks using visual feedback can be useful in training practitioners to produce appropriate traction forces during obstetric forceps deliveries. Residents of both sexes, but especially men, can generate traction forces exceeding the recommended limit. Unless tempered by training, forces generated from the sitting position in particular can often exceed the preferred range. LEVEL OF EVIDENCE: II-3.

Adult↗
PubMed2005

Regulation of signaling phosphoproteins by epidermal growth factor and Iressa (ZD1839) in human endometrial cancer cells that model type I and II tumors.

To understand how type I and II endometrial tumors uniquely respond to tyrosine kinase inhibitor treatments, we evaluated the signaling pathways of epidermal growth factor (EGF) receptor (EGFR) under the effects of EGF and Iressa (ZD1839, gefitinib) using Ishikawa H and Hec50co cells that model type I and II endometrial carcinomas, respectively. The cells were assayed for the expression of EGFR and both cell lines express an average of 100,000 EGFR per cell; however, Ishikawa H cells express higher levels of HER-2/neu compared with Hec50co cells (1.38 x 10(5) compared with 2.04 x 10(4), respectively). Using the Kinetworks multi-immunoblotting approach, which profiles 31 signaling phosphoproteins, the most striking result was that Hec50co cells show a higher number of basal phosphorylated sites compared with Ishikawa H cells. Furthermore, we identified targets of Iressa treatment in both cell lines. Iressa, at a dose of 1 micromol/L, blocked the autophosphorylation of EGFR in Ishikawa H and Hec50co cells with some distinctive effects on downstream effectors. Nevertheless, in both cell lines, EGF stimulated and Iressa blocked the major EGFR target mitogen-activated protein kinases extracellular signal-regulated kinase 1 and 2 equally. The high basal phosphorylation of numerous signaling molecules in Hec50co cells that were not inhibited by Iressa indicates that other growth factor pathways are active in addition to EGFR. We conclude that endometrial cancer cells that model type I and II carcinomas have the capacity to respond to EGFR inhibition as a therapeutic strategy; however, the response of the more aggressive type II tumors may be limited by the constitutive activation of other signaling pathways.

Antineoplastic Agents↗
PubMed2005

Oral contraceptives and skin cancer: is there a link?

The skin expresses estrogen, progesterone, and androgen receptors. In the presence of steroid hormones, such as those contained in oral contraceptives, the skin likely responds to hormonal signals that control the cell cycle, apoptosis, DNA replication, and other cellular functions. Some estrogen-responsive pathways have the potential to promote tumor development, including the augmentation of epidermal growth factor signaling, the expression of proto-oncogenes, and inhibition of apoptosis. The question of whether oral contraceptives increase the risk for the development of skin cancer, particularly melanoma, is still an area of concern. This paper reviews the available evidence, the bulk of which suggests that while the skin responds to estrogens, progestins, and androgens, these responses do not significantly increase the risk of developing skin cancer when estrogen exposure is not excessive.

Animals↗
PubMed2005

A therapeutic model for advanced endometrial cancer: systemic progestin in combination with local adenoviral-mediated progesterone receptor expression.

Cancer of the uterine endometrium is a frequent gynecologic malignant disease for which few therapeutic options are available for advanced disease. Progesterone is the normal female hormone that limits growth and proliferation of endometrial cancers; however, progesterone receptors are frequently down-regulated, leading to treatment failures. The current studies explored the effectiveness of adenoviral-mediated progesterone receptor gene transduction in combination with progestin therapy in mouse xenograft models. Pretreatment of cells with progesterone receptor-encoding adenovirus and progestin inhibited the development of s.c. tumors in athymic mice. In the i.p. xenograft model, replacement of both isoforms of progesterone receptor, PRA and PRB, in combination with progestin treatment resulted in a significant 2.6-fold increase in overall survival time compared with control animals. These studies indicate that when progesterone receptor levels are maintained, progestin therapy is effective in limiting tumor growth. Future therapeutic regimens targeted at enhancing progesterone receptor expression have the potential to improve outcomes in women with endometrial cancer.

Adenoviridae↗
PubMed2004

Immunomodulatory and transcriptional effects of progesterone through progesterone A and B receptors in Hec50co poorly differentiated endometrial cancer cells.

OBJECTIVE: Derivatives of progesterone, progestins, are used to treat endometrial cancer; however, the pathways activated by the hormone have not been fully investigated. Progesterone acts through two receptor isoforms, progesterone receptors A and B (PRA and PRB), transcription factors that control the expression of downstream genes leading to endometrial differentiation. The purpose of this study was to perform an expression analysis to identify the mechanisms underlying progesterone's growth suppressive and immunomodulatory effects in endometrial cancer. METHODS: To study the molecular effects of progesterone, PRs were introduced into Hec50co cells. Expression array analyses followed by confirmatory semiquantitive reverse-transcriptase polymerase chain reaction (RT-PCR) experiments were performed. RESULTS: Expression analysis demonstrated a significant effect of progesterone after 12 hours of treatment on a number of genes, including cell signaling, DNA remodeling, apoptotic, tumor-suppressor, and transcription factors. Of particular interest was the consistent modulation of cytokines, which generally predicted for a powerful anti-inflammatory effect of progesterone through PR. Specifically, pro-inflammatory genes such as TNFalpha, IL-1beta, and MCP-1/MCAF-1 were down-regulated and anti-inflammatory genes such as TRAP1 and SMAD4 were induced. CONCLUSION: We have discovered that progesterone has a modulatory effect on inflammation and many other important cellular functions. These effects likely underlie the inhibitory effects of progesterone on tumor growth and invasion.

Cytokines↗
PubMed2004

Identification of a novel mechanism of NF-kappaB inactivation by progesterone through progesterone receptors in Hec50co poorly differentiated endometrial cancer cells: induction of A20 and ABIN-2.

OBJECTIVE: Nuclear factor kappa B (NFkappaB) is a strong anti-apoptotic factor, which is constitutively active in human endometrial cancer cells. Progesterone is the principal growth inhibitory hormone in the endometrial epithelium and promotes apoptosis. To identify the pathways through which progesterone controls NFkappaB function, we explored its genomic and non-genomic effects in endometrial cancer cells. METHODS: PR-negative Hec50co endometrial cancer cells were engineered to express high levels of the A or B isoform of PR (PRA or PRB) by adenoviral infection. Cells were treated with progesterone or vehicle alone, and RNA was isolated. Affymetrix microarrays were performed and transcriptional control of the genes of highest interest was confirmed by semi-quantitative RT-PCR. To assess the non-genomic effects of PR on inflammation associated with NF-kappaB, electromobility shift assays (EMSAs) were performed. RESULTS: Expression analysis demonstrated a significant effect of progesterone after 12- and 24-h treatment on several genes; in particular, A20 and ABIN-2 were induced through PRB. These factors bind in a complex and inhibit NFkappaB transcriptional activity. In addition, EMSAs revealed the complete inhibition of NFkappaB dimer binding to DNA by both PRA and PRB. CONCLUSIONS: Progesterone is the principal differentiating hormone in the endometrium. We have now identified several down-stream pathways of action, one of which is the control of genes involved in NFkappaB activity. The tumorigenic inflammatory and anti-apoptotic effects of NFkappaB are inhibited by progesterone/PRB through the transcriptional control of binding proteins A20 and ABIN-2. This pathway offers interesting targets for future therapeutic development.

Adaptor Proteins, Signal Transducing↗
PubMed2003

Progesterone regulation of activating protein-1 transcriptional activity: a possible mechanism of progesterone inhibition of endometrial cancer cell growth.

The uterine endometrium and cancers derived from it are classic models of hormone action: estrogen promotes growth and progesterone inhibits proliferation and results in differentiation. We have now identified a major pathway through which progesterone causes these growth-limiting effects. Ligand-bound progesterone receptors modulate the composition and transcriptional activity of members of the activating protein-1 (AP-1) family, and in particular, c-Jun. First, a dominant negative form of c-Jun inhibits the constitutive growth of Hec50co cells in a manner similar to the effects of progesterone through progesterone B receptors. Second, progesterone inhibits the transcriptional activity of the AP-1 complex in reporter gene assays. Third, the DNA binding of AP-1 and the composition of the individual AP-1 factors on DNA is regulated by progesterone on electrophoretic mobility shift assays. Fourth, progesterone strongly inhibits total AP-1 as well as c-Jun recruitment to the cyclin D1 promoter, but enhances AP-1 occupancy on the p53 and p21 promoters, as shown by chromatin immunoprecipitation assays. The effects of progesterone on AP-1 DNA binding are confirmed to result in altered transcription of these AP-1 target genes by RT-PCR. These studies establish that modulation of AP-1 activity is a potential pathway of progesterone-induced growth inhibition in endometrial cancer cells.

Cell Division↗
PubMed2002

Progesterone inhibits human endometrial cancer cell growth and invasiveness: down-regulation of cellular adhesion molecules through progesterone B receptors.

Progesterone is a critical steroid hormone that controls cell proliferation and differentiation in the female reproductive tract. Progesterone acts through two nuclear receptor isoforms, progesterone receptors A and B (PRA and PRB, respectively), each with unique cellular effects. Loss of PRB has recently been linked to the development of poorly differentiated endometrial tumors, a lethal form of cancer. To study the molecular effects of progesterone, progesterone receptors were introduced into Hec50co endometrial cancer cells by adenoviral vectors encoding either PRA or PRB. Progesterone induced the cyclin-dependent kinase inhibitors p21 and p27, thereby significantly reducing the percentage of proliferating cells. Cancer cell invasion was also markedly inhibited as measured by Matrigel invasion studies. Similarly, a differentiated, secretory phenotype was induced by progesterone in cells expressing PRB. However, replicative senescence was induced by progesterone only in cells expressing PRA. Expression array analysis followed by confirmatory semiquantitative reverse transcription-PCR experiments demonstrated a significant progesterone-dependent inhibition of expression of a cadre of cellular adhesion molecules, including fibronectin, integrin alpha3, integrin beta1, integrin beta3, and cadherin 6. The level of down-regulation of adhesion molecule expression was significantly greater in the presence of the B isoform, demonstrating that progesterone acts principally through B receptors to inhibit cancer cell invasiveness modulated by adhesion molecules.

Apoptosis↗
PubMed2002

Chronic intrauterine infection and inflammation in the preterm rabbit, despite antibiotic therapy.

OBJECTIVE: In a pregnant rabbit model using intracervical inoculation of Escherichia coli with delayed antibiotic therapy, we investigated the rate of positive cultures and histologic inflammation of maternal and fetal compartments and the concentration of tumor necrosis factor-alpha in the amniotic fluid for up to 5 days. STUDY DESIGN: New Zealand White rabbits at 70% gestation were inoculated intracervically with 10(3) - 10(4) colony-forming units of E coli per uterine horn. At varying intervals after inoculation (0.5 - 4.0 hours), antibiotic therapy was initiated with ampicillin-sulbactam. Primary outcomes were positive cultures and histologic inflammation score. Tumor necrosis factor-alpha levels in the amniotic fluid were determined by bioassay. RESULTS: A total of 60 animals were inoculated with E coli. At the endpoint, uterine cultures were positive more commonly than in the fetus or amniotic fluid (41.8% vs 27.5% vs 17.3%, respectively), which was consistent with an ascending pathway of infection. Inflammation scores were similar in uterus and placenta but lower in fetal lung and absent in fetal brain (2.8 vs 3.1 vs 0.84 vs 0.0, respectively). Comparing the durations of delay in antibiotic administration, we found a significant increase in positive uterine cultures and a significant increase in histologic inflammation score with increasing delay. The proportion of dead pups within a litter was significantly associated with the log of the tumor necrosis factor-alpha concentration in amniotic fluid and the degree of histologic inflammation in the uterus, but not with amniotic fluid or other culture positivity. CONCLUSION: The administration of therapeutic doses of antibiotic does not consistently eradicate bacteria from the rabbit uterus nor, more importantly, from the fetus and the amniotic fluid. Obtaining a negative amniotic fluid culture does not exclude either infection in the decidua or the fetus or histologic inflammation with tumor necrosis factor-alpha elaboration.

Amniotic Fluid↗