cetrorelix and Endometrial-Neoplasms

Topics: Animals; Disease Models, Animal; Endometrial Neoplasms; Endometriosis; Female; Gonadotropin-Releasing Hormone; Hormone Antagonists; Humans; Leiomyoma; Luteinizing Hormone; Male; Ovarian Neoplasms; Receptors, LHRH; Testosterone; Uterine Neoplasms

AEZS-115 (Aeterna Zentaris GmbH, Frankfurt/M, Germany) is an orally active peptidomimetic antagonist of gonadotropin-releasing hormone (GnRH). In various tumors, an autocrine growth-promoting loop has been described for GnRH. The current study evaluates the antitumor activity and mechanism of action of AEZS-115 in models of ovarian and endometrial cancer.. Human A2780, Acis2780, OAW-42, Ovcar-3, SKOV-3, Hec1A and Ishikawa cells were analyzed for GnRH receptor expression by reverse transcription polymerase chain reaction (RT-PCR). These cell lines were incubated with AEZS-115 at 1, 10 and 100 μM for 24 h, 48 h, and 72 h and the number of viable cells was determined. Fluorescence activated cell sorting (FACS) cell cycle analyses were performed with increasing concentrations of AEZS-115. Co-treatment experiments of cancer cells with GnRH antagonist cetrorelix and peptidomimetic GnRH antagonist AESZ-115 were carried out.. A2780, Acis2780, OAW-42, Ovcar-3, SKOV-3, Hec1A and Ishikawa cells expressed GnRH receptors as demonstrated by RT-PCR. GnRH antagonist AEZS-115 inhibited growth of all cell lines in a dose- and time-dependent manner. Half maximal inhibitory concentration (IC(50)) values at 48 h of incubation were between 7 and 17.5 μM and for 72 h between 4.5 and 12.5 μM. IC(50) values for ovarian and endometrial cancer cells were rather similar. These results were obtained by tetrazolium salt [(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; MTT] assay and confirmed by additional crystal violet staining. Cell cycle FACS analysis revealed that AEZS-115 dose-dependently increased the fraction of apoptotic cells. Co-treatment experiments carried out with AEZS-115 and peptidic GnRH-antagonist cetrorelix suggest that the antitumor effect of AEZS-115 is not mediated by blockade of the GnRH receptor.. GnRH antagonist AEZS-115 exhibited substantial antitumor activity in ovarian as well as endometrial cancer cell lines. However, this antitumor effect was not mediated by the tumoral GnRH receptors. To identify the mechanism of action of this compound, further research is warranted. Its in vitro antitumor activity makes AEZS-115 a promising candidate for in vivo studies of ovarian and endometrial cancer.

Topics: Amino Acid Chloromethyl Ketones; Cell Cycle; Cell Line, Tumor; Endometrial Neoplasms; Female; Gonadotropin-Releasing Hormone; Humans; Ovarian Neoplasms; Peptidomimetics; Receptors, LHRH; RNA, Messenger

The majority of human endometrial and ovarian cancer cell lines express receptors for GnRH. Their proliferation is time- and dose-dependently reduced by GnRH-I and its superagonistic analogues. Recently, we have demonstrated that, in human endometrial and ovarian cancer cell lines except for the ovarian cancer cell line EFO-27, the GnRH-I antagonist cetrorelix has antiproliferative effects comparable to those of GnRH-I agonists, indicating that the dichotomy between GnRH-I agonists and antagonists might not apply to the GnRH system in cancer cells. We were also able to show that the proliferation of human endometrial and ovarian cancer cells was dose- and time-dependently reduced by GnRH-II to a greater extent than by GnRH-I agonists.. In this study we have assessed whether or not the antiproliferative effects of the GnRH-I antagonist cetrorelix in endometrial and ovarian cancer cells are mediated through the GnRH-I receptor.. We analysed the antiproliferative effects of the GnRH-I agonist triptorelin, the GnRH-I antagonist cetrorelix and GnRH-II in a panel of endometrial and ovarian cancer cell lines expressing GnRH-I receptors, in the SK-OV-3 ovarian cancer cell line that does not express GnRH-I receptors, and in four GnRH-I receptor positive GnRH-I receptor knockout cell lines.. We found that, after knockout of the GnRH-I receptor, the antiproliferative effects of the GnRH-I agonist triptorelin were abrogated, whereas those of the GnRH-I antagonist cetrorelix and of GnRH-II persisted.. These data suggest that, in endometrial and ovarian cancer cells, the antiproliferative effects of cetrorelix and of GnRH-II are not mediated through the GnRH-I receptor.

Topics: Antineoplastic Agents, Hormonal; Cell Division; Cell Line, Tumor; Endometrial Neoplasms; Female; Gonadotropin-Releasing Hormone; Hormone Antagonists; Humans; Mutagenesis; Ovarian Neoplasms; Receptors, LHRH; Triptorelin Pamoate

We studied the effects of luteinising hormone-releasing hormone (LHRH) agonist leuproreline (1 microM for 96 h) and LHRH antagonist cetrorelix on the cell growth of primary cultures from nine human endometrial cancers using the sulphorhodamine colorimetric test. Histological examinations and reverse transcription and polymerase chain reaction amplification (RT-PCR) for LHRH receptors were also performed. The endometrial cancers examined had a medium to high degree of proliferative activity and a low degree of apoptotic power; furthermore, they expressed the LHRH receptor RNA variably, detectable in 71% of cases. The addition of leuproreline or cetrorelix to cell cultures inhibited growth in a statistically significant way compared to untreated control cells; nevertheless, the percentage of cell growth inhibition obtained was very variable. These data suggest that LHRH analogues can exert differential inhibitory effects on the growth of endometrial cancer, which seems to be independent of the expression of specific LHRH receptors.

Topics: Aged; Cell Division; Endometrial Neoplasms; Female; Gonadotropin-Releasing Hormone; Humans; Leuprolide; Middle Aged; Postmenopause; Receptors, LHRH; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tumor Cells, Cultured

Our objective was to study the direct action of the gonadotropin-releasing hormone antagonist SB-75 and the agonist buserelin on the proliferation of endometrial cancer cells.. Two human endometrial cell lines that differ in histologic subtype and estrogen receptor content were treated with gonadotropin-releasing hormone analog. We measured the number of viable cells, cell cycle parameters, and apoptotic processes.. Growth of the Ishikawa cells was inhibited by SB-75 in a dose-dependent manner. 17 beta-Estradiol partially abolished the inhibitory effect of SB-75. The growth of the HEC-1A cells was not affected by the antagonist. Neither endometrial cancer cell line showed significant sensitivity to the agonist buserelin. Tenfold concentration of the gonadotropin-releasing hormone agonist did not abolish the inhibitory effect of the antagonist on cell growth. The growth inhibition was not associated with any change in cell cycle parameters but was associated with an induction of apoptosis.. The gonadotropin-releasing hormone antagonist SB-75 directly inhibits the growth of some human endometrial cancer cells and thus may be suitable for the treatment of endometrial tumors.

Topics: Adenocarcinoma, Papillary; Aged; Apoptosis; Buserelin; Cell Cycle; Cell Division; DNA, Neoplasm; Dose-Response Relationship, Drug; Electrophoresis, Agar Gel; Endometrial Neoplasms; Estradiol; Female; Flow Cytometry; Gonadotropin-Releasing Hormone; Humans; Receptors, Estrogen; Time Factors; Tumor Cells, Cultured

Although specific binding sites for LH-releasing hormone (LHRH) and its analogs have been demonstrated in biopsy samples of human endometrial cancer, their biological significance remains obscure. In this study we evaluated whether binding sites for LHRH are also present in the human endometrial cancer cell lines HEC-1A and Ishikawa and if such sites could mediate antiproliferative effects of LHRH analogs. Using [125I,D-Trp6]LHRH as a ligand, a high affinity/low capacity binding site was detected in both lines: HEC-1A line, dissociation constant (Kd)1 = 5.7 x 10(-9) mol/L, binding capacity (Bmax)1 = 78 fmol/10(6) cells; Ishikawa line, Kd1 = 4.2 x 10(-9) mol/L, Bmax1 = 29 fmol/10(6) cells. In addition, a second class of low affinity/high capacity binding sites for LHRH was demonstrated (HEC-1A line, Kd2 = 1.4 x 10(-6) mol/L, Bmax2 = 21 pmol/10(6) cells; Ishikawa, Kd2 = 4 x 10(-6) mol/L, Bmax2 = 32 pmol/10(6) cells). In the presence of 10(-5) mol/L agonist [D-Trp6]LHRH (triptorelin), the proliferation of HEC-1A and Ishikawa cell lines was significantly reduced to 76 +/- 2% and 88 +/- 4% of controls, respectively, after 24 h and to 64 +/- 2% and 62 +/- 2%, respectively, after 6 days. Dose-response experiments showed that lower concentrations (10(-9) mol/L) of the agonist decreased the proliferation to 80 +/- 1% for the HEC-1A line and 71 +/- 2% of controls for the Ishikawa line after 6 days. Antiproliferative effects are enhanced by increasing the doses of triptorelin and were maximal in this series of experiments at 10(-5) mol/L, the proliferation in the HEC-1A line being 62 +/- 1% and in the Ishikawa line 52 +/- 2% of controls, respectively. Similar time- and dose-dependent antiproliferative effects were obtained in both cell lines with the LHRH antagonist SB-75 (cetrorelix). These data suggest that LHRH analogs can directly inhibit the proliferation of human endometrial cancer cells in vitro. This direct action could be mediated through the high affinity LHRH binding sites.

Topics: Amino Acid Sequence; Binding Sites; Cell Division; Dose-Response Relationship, Drug; Drug Stability; Endometrial Neoplasms; Female; Gonadotropin-Releasing Hormone; Humans; Molecular Sequence Data; Triptorelin Pamoate; Tumor Cells, Cultured

The involvement of IGFs in growth regulation of the Ishikawa endometrial tumor cell line and the possible interference of LH-RH analogues with a potential autocrine or paracrine loop involving IGFs was evaluated. The mitogenic effects of IGF-I, IGF-II, and insulin were compared. IGF-I was found to be 3-fold more potent than IGF-II and 30-fold more potent than insulin, suggesting that the effects of these growth factors are mediated by the IGF-I receptor. Ishikawa endometrial cancer cells secrete IGF-II, but not IGF-I, and insulin (1 microM) stimulates IGF-II release. The LH-RH antagonist [Ac-D-Nal(2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Cit6, D-Ala10]-GnRH (SB-75, CETRORELIX) inhibited basal and IGF-induced growth. Moreover, this antagonist almost completely inhibited IGF-II release from Ishikawa cells, while having no significant effect on the number or affinity of IGF-I binding sites. Inhibition of IGF-II release occurred at a lower SB-75 concentration than that needed for a reduction in cell number. The ED50 of SB-75 for IGF-II release was 0.3 microM as compared to 1.5 microns concentration which is required for reduction in cell number, suggesting that inhibition of growth factor release precedes cell growth inhibition. We conclude that the LH-RH antagonist SB-75 can inhibit the growth of endometrial cancer cells by interfering with the autocrine action of IGF-II and also by directly inhibiting the growth-stimulatory effects of IGFs, probably through effects on a post-receptor mechanism.

Topics: Cell Division; Cell Line; Dose-Response Relationship, Drug; Drug Interactions; Endometrial Neoplasms; Female; Gonadotropin-Releasing Hormone; Humans; Insulin; Insulin-Like Growth Factor I; Insulin-Like Growth Factor II; Tumor Cells, Cultured