Effects of a combined treatment with mTOR inhibitor RAD001 and tamoxifen in vitro on growth and apoptosis of human cancer cells

OBJECTIVE: Interactions between estrogen receptor signaling and the PI3K/Akt pathway are present in estrogen-dependent cancer cells. Therapeutical inhibition of each of these pathways has been proven to exert antitumoral effects. Inhibition of mammalian target of rapamycin (mTOR), a downstream target of Akt, is able to restore tamoxifen response in tamoxifen-resistant breast cancer cells. Given that Akt and mTOR phosphorylation also is frequently detected in ovarian and endometrial cancer, we intended to find out to what extent mTOR inhibitor RAD001 (everolimus) and tamoxifen add to each other's effects on growth and apoptosis of cancer cell lines derived from these tissues when given concomitantly. METHODS: OVCAR-3 and SK-OV-3 ovarian cancer cells, HEC-1A endometrial adenocarcinoma cells and MCF-7 breast cancer cells were treated with different concentrations of mTOR inhibitor RAD001 alone or in combination with 4-OH tamoxifen. Relative numbers of viable cells were assessed by means of the resazurin-based Cell Titer Blue assay, cellular apoptosis was examined by measurement of activated caspases 3 and 7 by means of the luminometric Caspase-Glo assay. RESULTS: Treatment with RAD001 resulted in growth inhibition of all employed cancer cell lines in a dose-dependent manner, and SK-OV-3 ovarian cancer cells proved to be most sensitive to this drug. Moreover, we report the observation of additive, but not synergistical growth inhibitory effects of a combination treatment with RAD001 and 4-OH TAM on SK-OV-3 and OVCAR-3 ovarian cancer cells and MCF-7 breast cancer cells in vitro, whereas no such effect was observed in HEC-1A endometrial adenocarcinoma cells. Combination treatment with both drugs was demonstrated to be superior to single treatment with lower concentrations (0.1 and 1 nM) of RAD001 or standard concentrations of 4-OH TAM. Furthermore, RAD001 increased the apoptotic effect triggered by high 4-OH TAM concentrations in SK-OV-3 ovarian cancer cells. CONCLUSION: Combination treatment with RAD001 and 4-OH TAM in vitro exerts an additive antitumoral effect on ovarian cancer cells and MCF-7 breast cancer cells. The significance of these data in the clinical situation has to be evaluated in further studies.     

Increase of doxorubicin-induced apoptosis after knock-down of gonadotropin-releasing hormone receptor expression in human endometrial, ovarian and breast cancer cells.

The majority of human endometrial, ovarian and breast cancers express receptors for gonadotropin-releasing hormone (GnRH). Their proliferation is time- and dose-dependently reduced by GnRH and its agonistic analogs. GnRH agonists inhibit the mitogenic signal transduction of growth factor receptors via activation of a phosphotyrosine phosphatase, resulting in downregulation of cancer cell proliferation. Induction of apoptosis is not involved. Recently we showed that the GnRH agonist triptorelin induces activation of nuclear factor-kappaB (NFkappaB) and thus reduces the apoptosis induced by the cytotoxic agent doxorubicin in human endometrial and ovarian cancer cells. The triptorelin-induced reduction of doxorubicin-induced apoptosis was blocked by inhibition of NFkappaB translocation into the nucleus. The present study was conducted to investigate whether knock-down of GnRH receptor expression reduces GnRH agonist-induced anti-apoptotic action. We show that knock-down of GnRH receptor expression results in an increase of doxorubicin-induced apoptosis in human endometrial and ovarian cancers and in the human breast cancer cell line MCF-7. These data further demonstrate that GnRH agonists suppress chemotherapeutic drug-induced apoptosis via activation of the GnRH receptor in these cancers. The situation is different with T-47-D breast cancer cells. After knock-down of GnRH receptor expression doxorubicin-induced apoptosis was decreased, indicating that GnRH agonists do not suppress chemotherapeutic drug-induced apoptosis in T-47-D breast cancer cells.     

Increase of doxorubicin-induced apoptosis after knock-down of gonadotropin-releasing hormone receptor expression in human endometrial,ovarian and breast cancer cells

The majority of human endometrial, ovarian and breast cancers express receptors for gonadotropin-releasing hormone (GnRH). Their proliferation is time- and dose-dependently reduced by GnRH and its agonistic analogs. GnRH agonists inhibit the mitogenic signal transduction of growth factor receptors via activation of a phosphotyrosine phosphatase, resulting in downregulation of cancer cell proliferation. Induction of apoptosis is not involved. Recently we showed that the GnRH agonist triptorelin induces activation of nuclear factor-κB (NFκB) and thus reduces the apoptosis induced by the cytotoxic agent doxorubicin in human endometrial and ovarian cancer cells. The triptorelin-induced reduction of doxorubicin-induced apoptosis was blocked by inhibition of NFκB translocation into the nucleus.

The present study was conducted to investigate whether knock-down of GnRH receptor expression reduces GnRH agonist-induced anti-apoptotic action. We show that knock-down of GnRH receptor expression results in an increase of doxorubicin-induced apoptosis in human endometrial and ovarian cancers and in the human breast cancer cell line MCF-7. These data further demonstrate that GnRH agonists suppress chemotherapeutic drug-induced apoptosis via activation of the GnRH receptor in these cancers. The situation is different with T-47-D breast cancer cells. After knock-down of GnRH receptor expression doxorubicin-induced apoptosis was decreased, indicating that GnRH agonists do not suppress chemotherapeutic drug-induced apoptosis in T-47-D breast cancer cells.     

Internalization of cytotoxic analog AN-152 of luteinizing hormone-releasing hormone induces apoptosis in human endometrial and ovarian cancer cell lines independent of multidrug resistance-1 (MDR-1) system

OBJECTIVE: Eighty percent of human ovarian and endometrial cancers express receptors for luteinizing hormone-releasing hormone (LHRH-R). These receptors can be used for targeted chemotherapy with agents such as AN-152, in which doxorubicin is linked to analog [D-Lys(6)]-LHRH. Direct receptor-mediated antiproliferative effects of AN-152 have been shown in vitro and in vivo. In LHRH-R positive cell lines, AN-152 was more effective than doxorubicin at equimolar concentrations. This study was designed to investigate the mechanism of action of AN-512 in ovarian and endometrial cancer cells in vitro.Study design Three ovarian (SKOV-3, NIH:OVCAR-3, EFO-21) and 2 endometrial carcinoma cell lines (Ishikawa, HEC-1A) were evaluated for doxorubicin- or AN-152-induced apoptosis. Internalization and cytoplasmic release of AN-152 was monitored by confocal laser scanning microscopy and inhibited by chloroquine. Cleavage of doxorubicin from AN-152 was inhibited by carboxylesterase inhibitor, diisopropyl fluorophosphate (DFP). The surface expression of multidrug resistance-1 (MDR-1) gene product P-glycoprotein (Pgp) was measured by flow cytometry. RESULTS: Induction of apoptosis by AN-152 in LHRH-R positive Ishikawa, HEC-1A, EFO-21, and NIH:OVCAR-3 cells was significantly higher than that induced by doxorubicin, whereas the percentage of apoptotic cells in LHRH-R negative SKOV-3 was higher after treatment with doxorubicin. In EFO-21 cells, apoptosis induced by AN-152 was inhibited by pretreatment with chloroquine. Pretreatment with DFP increased AN-152-induced apoptosis in LHRH-R positive cells and reduced apoptosis in LHRH-R negative SKOV-3. Both AN-152 and doxorubicin induced surface expression of MDR-1 gene product Pgp, but the effect of AN-152 was smaller than that of doxorubicin. Pgp surface expression induced by AN-152 was inhibited by pretreatment with DFP. CONCLUSION: AN-152 is internalized through the LHRH-R and induces apoptosis in LHRH-R-positive human ovarian and endometrial cancer cell lines without activating the MDR-1 efflux pump system. The efficacy and specificity of AN-152 is inversely correlated with carboxylesterase activity.     

M344 is a novel synthesized histone deacetylase inhibitor that induces growth inhibition, cell cycle arrest, and apoptosis in human endometrial cancer and ovarian cancer cells

OBJECTIVE: Histone deacetylase inhibitors (HDACIs) can inhibit cell proliferation, induce cell cycle arrest, and stimulate apoptosis of cancer cells. METHODS: We investigated the effects of a novel synthesized HDACI, M344, on Ishikawa endometrial cancer cell line, SK-OV-3 ovarian cancer cell line, and normal human endometrial epithelial cells. Endometrial and ovarian cancer cells were treated with various concentrations of M344, and its effect on cell growth, cell cycle, apoptosis, and related measurements was investigated. RESULTS: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays showed that all endometrial and ovarian cancer cell lines were sensitive to the growth inhibitory effect of M344, although normal endometrial epithelial cells were viable after the treatment with the same doses of M344 that induced growth inhibition of endometrial and ovarian cancer cells. Cell cycle analysis indicated that their exposure to M344 decreased the proportion of cells in the S-phase and increased the proportion in the G0/G1 phases of the cell cycle. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and loss of the transmembrane potential of mitochondria. This induction occurred in concert with altered expression of genes related to cell growth, malignant phenotype, and apoptosis. Furthermore, M344 treatment of these cell lines increased acetylation of H3 and H4 histone tails. CONCLUSIONS: These results raise the possibility that M344 may prove particularly effective in the treatment of endometrial cancers and ovarian cancers.     

Presence of epidermal growth factor (EGF) receptor and proliferative response to EGF in six human ovarian carcinoma cell lines

Abstract. Scambia G, Benedetti Panici P, Battaglia F, Ferrandina G, Gaggini C, Mancuso S. Presence of epidermal growth factor (EGF) receptor and proliferative response to EGF in six human ovarian carcinoma cell lines. Int J Gynecol Cancer 1991; 1 : 253–258.
We investigated the role of the EGF-EGFR system as a regulator of ovarian cancer cell growth. In five (OVCA 433, OV 166, OV 1225, OV RS 1000, JA1) of six ovarian cancer cell lines examined we showed the presence of a single high-affinity ¹²⁵I-EGF binding site with Kd varying from 0.24 to 0.86 nM and a number of binding sites/cell from 9700 to 75 000. In OVCA 433, OV 166, and OV RS 1000 cells we demonstrated a low-affinity ¹²⁵I-EGF binding site with Kd ranging from 1.10 to 2.12 nM.
TR-170 cells lacked the EGF binding and were unresponsive to EGF in terms of cell proliferation while all EGFR+ cells except JA 1 exhibited a proliferative response to EGF. Moreover, the growth response of the four EGF-sensitive cell lines showed different patterns since at high EGF concentrations (100 ng ml⁻¹) there was no longer a stimulatory effect in OV 1225, OV 166, and OV RS 1000 cells while the mitogenic activity was still present in OVCA 433 cells.
Our results demonstrate that EGF plays a role in regulating ovarian cancer cell growth. However, the presence of EGFR is not a perfect indicator of the EGFR system functionality. The cell lines we have examined could be useful models to clarify the mechanism of EGF action and the role played by the EGF system in the onset and spread of ovarian tumors.     

DNA profiling analysis of endometrial and ovarian cell lines reveals misidentification, redundancy and contamination

Objectives

Cell lines derived from human ovarian and endometrial cancers, and their immortalized non-malignant counterparts, are critical tools to investigate and characterize molecular mechanisms underlying gynecologic tumorigenesis, and facilitate development of novel therapeutics. To determine the extent of misidentification, contamination and redundancy, with evident consequences for the validity of research based upon these models, we undertook a systematic analysis and cataloging of endometrial and ovarian cell lines.

Methods

Profiling of cell lines by analysis of DNA microsatellite short tandem repeats (STR), p53 nucleotide polymorphisms and microsatellite instability was performed.

Results

Fifty-one ovarian cancer lines were profiled with ten found to be redundant and five (A2008, OV2008, C13, SK-OV-4 and SK-OV-6) identified as cervical cancer cells. Ten endometrial cell lines were analyzed, with RL-92, HEC-1A, HEC-1B, HEC-50, KLE, and AN3CA all exhibiting unique, uncontaminated STR profiles. Multiple variants of Ishikawa and ECC-1 endometrial cancer cell lines were genotyped and analyzed by sequencing of mutations in the p53 gene. The profile of ECC-1 cells did not match the EnCa-101 tumor, from which it was reportedly derived, and all ECC-1 isolates were genotyped as Ishikawa cells, MCF-7 breast cancer cells, or a combination thereof. Two normal, immortalized endometrial epithelial cell lines, HES cells and the hTERT-EEC line, were identified as HeLa cervical carcinoma and MCF-7 breast cancer cells, respectively.

Conclusions

Results demonstrate significant misidentification, duplication, and loss of integrity of endometrial and ovarian cancer cell lines. Authentication by STR DNA profiling is a simple and economical method to verify and validate studies undertaken with these models.     

LHRH拮抗剂Cetrorelix对子宫内膜癌细胞生长周期的影响及其机理

目的 :研究LHRH拮抗剂Cetrorelix对子宫内膜癌细胞生长周期及周期相关蛋白的影响 ,探讨其抑制内膜癌细胞生长的机理。方法 :用流式细胞仪细胞周期分析及Westernblotting蛋白分析法 ,研究在Cetrorelix的作用下子宫内膜癌细胞系HEC 1A细胞生长周期及相关周期蛋白的改变。结果 :1 0 -5mol/LCetrorelix可导致HEC 1A细胞生长停滞于G2 /M期 ,而与G2 /M期停滞相关的p5 3 ,磷酸化p5 3 (phospho p5 3 ) (丝氨酸 3 92 )及磷酸化cdc2 (phospho cdc2 ) (酪氨酸 1 5 )蛋白水平均显著增高。结论 :Cetrorelix抑制内膜癌细胞增殖作用的机理是结合细胞表面受体后引起一系列抑制性信号传递 ,导致细胞周期停滞于G2 /M期 ,主要表现为G2 期停滞。其中p5 3激活及cdc2磷酸化失活是引起细胞周期停滞的重要因素     

Phase II study of cetrorelix,a luteinizing hormone-releasing hormone antagonist in patients with platinum-resistant ovarian cancer

OBJECTIVE: The goal of this work was to study the anticancer activity of cetrorelix, a decapeptide with LHRH receptor antagonist properties in patients with platinum-resistant ovarian cancer. About 80% of primary ovarian cancers and cell lines bear LHRH receptors. Cetrorelix has anticancer activity in in vitro and in vivo ovarian cancer models. METHODS: Eligible patients with ovarian or mullerian carcinoma resistant to platinum chemotherapy received cetrorelix 10 mg subcutaneously every day. Eligibility criteria included age > or = 18, PS < or = 2, measurable disease, chemistries and blood counts in normal range, no estrogen replacement for at least 2 weeks, and no known allergic reactions to extrinsic peptide. In patients volunteering for a biopsy, tissue was taken to perform a LHRH receptor assay. RESULTS: Seventeen patients were treated. Median age was 58 years. Median performance status was 0. Median number of prior chemotherapies was 3. Three patients had partial remissions lasting 9, 16, and 17 weeks. Toxicities effects included grade 4 anaphylactoid reaction (one patient) controlled by cortisol and cimetidine, grade 2 histamine reaction (two patients), grade 2 arthralgia (one patient) 20% cholesterol increase (two patients, who did not require specific treatment), minor hot flushes, headache, and local skin reaction at the injection site. Six of seven samples were LHRH receptor positive for mRNA and/or ligand assay. Two responding patients were LHRH receptor positive. The patient who had no receptor did not respond. CONCLUSION: Cetrorelix has activity against ovarian cancer in this refractory population, and has minimal toxicity, except for potential anaphylactoid reactions. Activity may be mediated through the LHRH receptor.     

Biological implications of growth factors on the mechanism of invasion in gynecological tumor cells.

We investigated the effects of epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) on migration, invasion and proteinase expression of gynecological cultured cancer cells (SKG-IIIb cervical squamous cell carcinoma, OMC-4 cervical adenocarcinoma, SNG-M endometrial adenocarcinoma and OMC-3 ovarian adenocarcinoma), and whether these growth factors affect thymidine phosphorylase/platelet-derived endothelial cell growth factor expression of tumor cells. Tumor cell migration along a gradient of substratum-bound fibronectin and invasion into reconstituted basement membrane were stimulated by 0.1-10 nM EGF and TGF-alpha in a concentration-dependent manner. The zymography of tumor-conditioned medium showed that the treatment of tumor cells with EGF and TGF-alpha resulted in the increase of type IV collagenases, stromelysin and urokinase-type plasminogen activator which was partly confirmed by immunoblot analysis. The expression of thymidine phosphorylase/platelet-derived endothelial cell growth factor which has angiogenic activity, was also upregulated by these growth factors. These results suggest that EGF and TGF-alpha act as positive regulators on the invasion process of gynecological tumor cells which may be associated with their stimulatory action on the motility of tumor cells, the expression of proteinases secreted by tumor cells and the angiogenic phenotype.     

Daunorubicin conjugated to a monoclonal anti-CA125 antibody selectively kills human ovarian cancer cells

The present study was designed to test the in vitro efficacy for human ovarian cancer cells of daunorubicin (DNR) conjugated to a monoclonal antibody (OC125). The OC125 antibody specifically binds to the antigenic protein CA125 from human ovarian carcinoma. New analogs of DNR containing various linker groups were conjugated to mouse monoclonal anti-CA125 antibody (DNR-OC125); nonspecific murine IgG1 (DNR-IgG1); or bovine serum albumin (DNR-BSA). The DNR-protein conjugates were all stable for several days in neutral solutions at room temperature. The DNR-OC125 conjugates selectively killed dividing cell populations but not nondividing cell populations of two human ovarian cancer cell lines (SK-OV-3 or OVCAR-3) that express the CA125 antigen. Equivalent concentrations of DNR-IgG1 or DNR-BSA conjugates were neither toxic to the dividing nor the nondividing populations of SK-OV-3 or OVCAR-3 cells. Only those DNR-protein conjugates linked to OC125 were cytotoxic to dividing cell populations of both cell lines. This indicates that cytotoxicity is dependent on OC125 antibody-CA125 antigen binding which concentrates DNR on the ovarian cancer cells. We advance the hypothesis that following antibody-antigen binding, DNR is released from the conjugate and it intercalates in DNA by a mechanism similar to that of the unmodified DNR. The new DNR-OC125 conjugate may be useful for delivering DNR to ovarian tumors that express the CA125 antigen because the drug-antibody conjugates (1) retain the cytotoxic characteristics of the unmodified drug: (2) specifically kill the human ovarian cancer cells that express the CA125 antigen; and (3) are completely stable for days in neutral solutions at room temperature.     

Significant reduction of the incidence of ovarian hyperstimulation syndrome (OHSS) by using the LHRH antagonist Cetrorelix (Cetrotide®) in controlled ovarian stimulation for assisted reproduction

A prospective, randomized study was performed to compare the efficiency of hormonal stimulation for IVF (in vitro fertilization) in either the long luteal protocol, using the LHRH agonist Buserelin, or the multiple dose LHRH antagonist protocol, using the LHRH antagonist Cetrorelix. Here we present the data on the incidence of ovarian hyperstimulation syndromes (OHSS). 85 and 188 patients were recruited for the stimulation in the LHRH agonist and in the LHRH antagonist protocol, respectively. The groups were comparable regarding anamnestic data. The incidence of WHO °II and °III OHSS was significantly lower in the Cetrorelix than in the Buserelin group (1.1% vs. 6.5%, p=0.03). Additionally 3 patients in the Cetrorelix group (1.6%) and 5 patients in the Buserelin group (5.9%) did not receive hCG because of a threatening OHSS. The follicle maturation was more homogeneous in the Cetrorelix protocol, with less small follicles on the day of hCG administration but a similar number of oocyte cumulus complexes retrieved. The pregnancy rates per cycle were not significantly different in the Cetrorelix and Buserelin protocol (22% vs. 26%). The Cetrorelix multiple dose protocol is advantageous compared to the long protocol regarding the incidence of OHSS, a potentially life threatening complication of controlled ovarian stimulation. Received: 24 March 2000 / Accepted: 7 April 2000     

Necrotic cell death of ovarian adenocarcinoma caused by seminal plasma

Objective. From the knowledge of risk factors of epithelial ovarian cancer, we deduced a hypothesis that human seminal plasma (HSP) has a preventive role in the development of epithelial ovarian cancer. To examine whether HSP directly influences the growth of ovarian cancer, we have investigated the in vitro and in vivo effect of HSP on ovarian adenocarcinoma cell lines (SK-OV-3 and OVCAR-3) in comparison with its effects on normal ovarian surface epithelial cells (NOSE).Methods. Cell viability was determined by MTT assay. Cytotoxic effect was evaluated by flow cytometry analysis, by DNA laddering, and by morphological analysis. In vivo therapeutic effect of HSP was evaluated by the subcutaneous inoculation of SK-OV-3 cells in nude mice (BALB-c) model.Results. HSP at a final concentration of 1:50 induced a time- and dose-dependent inhibition of SK-OV-3 and OVCAR-3 growth, whereas NOSE was not affected. Flow cytometric analysis, DNA laddering, and morphological analysis indicated that HSP induced necrosis, rather than apoptosis, of both ovarian carcinoma cell lines. In in vivo experiment that used the nude mice (Balb-C) with tumor inoculation of SK-OV-3 cells, HSP induced necrosis of tumor with no detectable toxic effects on the major organs.Conclusion. These results show that HSP inhibits the growth and induces the necrosis of epithelial ovarian cancer cells and suggests that one or more components of HSP may provide a scientific basis for preventing epithelial ovarian cancer.     

Expression of cell-cycle mediators in ovarian cancer cells after transfection with p16(INK4a), p21(WAF1/Cip-1), and p53.

OBJECTIVE: The purpose of this study was to determine whether transfection of ovarian cancer cell lines with recombinant adenoviral vectors containing wild-type p16(INK4a), p21(WAF1/Cip-1), and p53 caused growth inhibition and induction of apoptosis. We also measured the expression of the cell-cycle mediators Bax, Bcl-2, pRb, and mdm-2. METHODS: We introduced the wild-type p16(INK4a), p21(WAF1/Cip-1), and p53 genes into the ovarian cancer cell lines SK-OV-3 (p16(INK4a) and p53 null) and OVCA-420 (p16(INK4a) and p53 wild-type) by adenoviral transfection. Cell growth inhibition was measured over a 10-day period. Induction of apoptosis was tested for both cell lines 48 h after cell transfection. Expression of cell-cycle mediators was evaluated by Western blot analysis and densitometry. RESULTS: Growth inhibition was documented after transfection with p16(INK4a), p21(WAF1/Cip-1), and p53 in both SK-OV-3 cells and OVCA-420 cells. Apoptosis was greatest in SKOV-3 cells after transfection with p53. A significant expression of Bax was only seen in the SKOV-3 cells transfected with p53. The bcl-2 protein was poorly expressed in both cell lines. Expression of pRb was suppressed in OVCA-420 cells transfected with p16(INK4a) and p21(WAF1/Cip-1). Infection with Adp16(INK4a) and Adp53 led to an increase in the level of mdm-2 in the SK-OV-3 cell line only. CONCLUSIONS: In the ovarian cancer cell lines studied, cell growth was inhibited after transfection with p16(INK4a), p21(WAF1/Cip-1), and p53. Cell cycle arrest was highest with p53 transfection. The expression of pro-apoptosis proteins was primarily a function of p53 expression.     

天蚕素 B-黄体生成素释放激素结合部位重组基因的构建及其抑癌功能的研究

目的构建天蚕素B-黄体生成素释放激素结合部位（CB-LHRH’）重组基因,探讨CB-LHRH’蛋白成为新型抗肿瘤靶向药物的可能性。方法设计并人工合成CB-LHRH’重组基因序列,应用昆虫细胞．杆状病毒表达系统表达目的蛋白并通过蛋白斑点印迹法鉴定,采用二甲氧唑黄（XTT）比色法检测不同剂量的目的蛋白对卵巢上皮性癌细胞株SKOV3（LHRH受体阴性）和子宫内膜癌细胞株HEC-1B（LHRH受体阳性）细胞的生长抑制率,并进行镜下形态观察。结果蛋白斑点印迹法检测结果显示,重组杆状病毒感染的Si9细胞裂解液呈现棕色,证实CB-LHRH’蛋白已表达。重组杆状病毒感染的昆虫细胞系Sf9细胞裂解液对SKOV3及HEC-1B细胞的生长抑制率,随作用时间的延长和剂量的增加而增加,SKOV3细胞的生长抑制率从（5.03±0.08）％增加至（53.24±1.22）％,HEC-1B细胞的生长抑制率从（5.13±0.37）％增加至（56.16±1.08）％。相同剂量的重组杆状病毒感染的St9细胞裂解液,作用相同时间,其对HEC-1B细胞的生长抑制率高于SKOV3细胞,差异有统计学意义（P〈0.01）。经重组杆状病毒感染的St9细胞裂解液作用后,镜下可见癌细胞出现明显改变甚至成片坏死崩解为无定形的颗粒状物质。结论CB-LHRH’蛋白可有效杀伤LHRH受体阳性的HEC-1B细胞,有望成为治疗表达LHRH受体的肿瘤的抗肿瘤靶向药物。     

Paradoxical ovarian stimulations in the use of LHRH analogs.

In the case of in vitro fertilization, LHRH analogs are used to induce a hypophysial blockage before the phase of stimulation, via administration of exogenous gonadotropin. During in vitro fertilization attempts using LHRH analogs, the blockage is controlled after 14 days of treatment by measuring plasmatic estradiol and by pelvic ultrasonography. In this retrospective study, which concerned 1075 in vitro fertilization cycles, a paradoxical ovarian stimulation with LHRH analogs was observed in 93 cases (8.7%) with high estradiol levels and follicular growth (detected by ultrasonography), in spite of low FSH and LH levels. In 4 cases, a follicular puncture was performed, which made it possible to collect oocytes from which embryos were obtained, thus confirming the observed follicular growth and maturation. The most probable hypothesis explaining this phenomenon seems to be direct ovarian stimulation effectuated in vivo by LHRH analogs. This stimulation is only observed in certain patients, and, more frequently it seems, with certain LHRH analogs, which is probably due to a variation in the expression of ovarian LHRH receptors.