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Biomedical subjects

A Sourla

Publications and source records attributed to A Sourla.

At least 19 recordsLinked to original sources
PubMed2005

Bone microenvironment-related growth factors, zoledronic acid and dexamethasone differentially modulate PTHrP expression in PC-3 prostate cancer cells.

Bone metastasis microenvironment-related growth factors such as insulin-like growth factor 1 (IGF-1), transforming growth factor beta 1 (TGF-beta1), basic fibroblast growth factor (bFGF) and interleukin 6 (IL-6) show survival factor activity, thereby inhibiting chemotherapy-induced apoptosis of PC-3 prostate cancer cells in vitro. Recently, zoledronic acid has been shown to induce apoptosis in PC-3 prostate cancer cells while overexpression of parathyroid hormone-related protein (PTHrP) inhibits serum deprivation-induced apoptosis in PC-3 cells. Consequently, we have investigated whether IGF-1, TGF-beta1, bFGF, IL-6, zoledronic acid and/or dexamethasone affect the expression of the PTHrP and type I PTH/PTHrP receptor (PTH.1R) in PC-3 prostate cancer cells using relative quantitative PCR and real-time PCR (expression at mRNA level) and immunocytochemical and immunofluorescence analysis (expression at protein level). Our data show that IGF-1, TGF-beta1, bFGF and IL-6 increase PTHrP mRNA expression and its perinuclear localization, while zoledronic acid (50 muM, 100 muM for 24 h and 48 h) and dexamethasone suppress PTHrP expression in PC-3 cells. We did not detect any appreciable change of the PTH.1R expression due to IGF-1, TGF- beta1, bFGF, IL-6, zoledronic acid or dexamethasone in PC-3 cells. Therefore, it is conceivable that bone metastasis microenvironment-related survival factor/anti-apoptotic activity and zoledronic acid anticancer action/pro-apoptotic activity on PC-3 cells is mediated, at least in part, by differential modulation of PTHrP expression.

Bone and Bones↗
PubMed2001

Increased insulin-like growth factor 1 activity can rescue KLE endometrial-like cells from apoptosis.

BACKGROUND: The peritoneal fluid (PF) of women with endometriosis contains protease(s) activity able to hydrolyze insulin-like growth factor-binding protein 3 (IGFBP-3), increasing the bioavailability of insulin-like growth factor-1 (IGF-1) locally. Therefore, we characterized the effects of IGF-1 on KLE endometrial-like cells in vitro. MATERIALS AND METHODS: The mitogenic effect of IGF-1 was assessed by the analysis of the DNA content and cell count. Apoptosis was triggered experimentally by the 48 hr exposure of KLE cells to 100 nM of adriamycin in the presence and absence of IGF-1 (50 ng/ml). Adriamycin apoptosis of KLE cells was determined by the number of dead KLE cells using trypan blue exclusion and by the DNA fragmentation on simple agarose gel and flow cytometry of propidium iodide and HOECHST 33342-stained KLE cells using an EPICS 753 pulse cytometer. RESULTS: IGF-1 stimulated the growth of KLE cells in a dose-dependent manner (optimal dose of 50 ng/ml) and protected KLE cells from adriamycin (100 nM)-induced apoptosis. CONCLUSIONS: These data suggest that IGF-1 is a survival factor for KLE cells. Conceivably, increased IGF-1 activity in the PF can optimize both the survival and ectopic growth of endometrial cells in the peritoneal cavity.

Apoptosis↗
PubMed2000

Exclusive androgenic effect of dehydroepiandrosterone in sebaceous glands of rat skin.

In order to analyze the hormonal effects of dehydroepiandrosterone (DHEA) in skin sebaceous glands, the precursor steroid was administered to ovariectomized (OVX) female Sprague-Dawley rats at a dose of 30 mg applied on the dorsal skin, twice daily, for 3, 6 and 12 months. In a parallel experiment, female OVX rats were treated with DHEA at the same daily percutaneous dose of 30 mg, alone or in combination with the antiandrogen Flutamide or the pure antiestrogen EM-800, for 12 months, in order to determine the androgenic and/or estrogenic components of DHEA action. Treatment of female OVX rats with DHEA resulted in a similar mild to moderate hyperplasia of the sebaceous glands of both dorsal (site of application) and ventral skin, as illustrated by an increase in the number and size of the acini. The above-indicated effects were observed at all time intervals studied, beginning at 3 months of treatment, and they were not further increased after longer term administration of DHEA (for 6 and 12 months). The addition of Flutamide to DHEA treatment completely prevented the DHEA-induced changes in the sebaceous glands, whereas the antiestrogen EM-800 had no effect. The present data indicate an exclusive androgenic stimulatory action of DHEA on the sebaceous glands, thus pointing out the importance of local intracrine DHEA transformation into androgens for skin anatomical integrity and function, while showing that estrogens, if active in rat skin, do not originate from DHEA.

Administration, Cutaneous↗
PubMed2000

Three-dimensional type I collagen co-culture systems for the study of cell-cell interactions and treatment response in bone metastases.

The available monolayer culture systems for the study of bone metastases constitute a suboptimal simulation of the in vivo pathophysiology of bone metastases, and therefore, do not provide sufficient information to assess the morphologic evidence of bone reaction to cancer cells, the nature of cell-specific mediators of osteolysis and osteoplasia and the response to treatment. Therefore, we have developed a three-dimensional (3-D) type I collagen gel system that allows co-culture of human osteoblasts (MG-63) with cancer cells, such as MCF-7, MDA-MB-231 or ZR-75 breast cancer cells, PC-3 prostate cancer, KLE endometrial cancer cells and Calu-1 lung cancer cells. We used type I collagen purified from rat tail tendons and the 3-D system was prepared by mixing MG-63 cells with type I collagen in 24-well plates. The 3-D system was inoculated with cancer cells and processed with standard cell culture procedures. After 1 week of culture, the matrix gel was fixed with formalin and embedded in paraffin. Serial sections were stained with trichrome Masson stain and modified Masson-Goldner stain, as well as analyzed by in situ hybridization, immunohistochemistry and the TUNEL technique for semi-quantitative detection of apoptotic cell death, assessing the response to adriamycin therapy. The inoculation of PC-3 cells in this collagen matrix produced a blastic reaction, documented by an increased number of MG-63 cells and increased density of type I collagen. The human KLE cells and inoculation of cell-free media produced no reaction, while ZR-75, MCF-7 and Calu-1 cells produced local degradation of the collagen matrix. In situ hybridization revealed the expression of Insulin-like growth factor 1 (IGF-1) and urokinase-type plasminogen activator (uPA) mRNA, while immunohistochemistry detected differential expression of uPA and cathepsin D. Adriamycin induced apoptotic cell death in prostate cancer cells and estrogen receptor negative (ER-) MDA-MB-231 breast cancer cells, while adriamycin did not induce apoptosis but cytostasis in ER+ MCF-7 cells. The adriamycin-induced apoptosis was inhibited by co-culture with osteoblast-like cells (MG-63). We conclude that this 3-D culture system is a useful in vitro model allowing the analysis of local mediators of osteolytic and osteoblastic reactions to bone metastases and treatment response.

Journal Article↗
PubMed2000

Cancer and bone repair mechanism: clinical applications for hormone refractory prostate cancer.

It is a long-standing clinical observation that the bone corresponds to the prevalent site for metastatic growth of prostate cancer. In addition, bone metastases of this malignancy produce a potent blastic reaction, in contrast to the overwhelming majority of other osteotropic neoplasms, whose metastases are generally associated with an osteolytic reaction. Osteoblastic metastases represent almost always the first and, frequently, the exclusive site of disease progression to hormone refractory stage, stage D3. Moreover, the number of skeletal metastatic foci is the most powerful independent prognostic factor associated with a limited response to hormone ablation therapy and poor survival of advanced prostate cancer. It is noteworthy that disease progression to hormone refractory stage occurs almost always in osteoblastic metastases. These clinical observations suggested that the osteoblastic reaction is possibly not an innocent bystander of the metastatic prostate tumour growth, simply suffering its consequences, but it may in fact facilitate the efforts of metastatic cells to expand their population. An extensive line of research in the pathophysiology of osteoblastic metastases has established that the local blastic reaction involves the uPA/plasmin/IGF/IGFBP-3/TGFbs bioregulation system which can stimulate both the growth of osteoblasts and prostate cancer cells. Furthermore, we were the first to characterize osteoblast-derived 'survival factors' able to rescue metastatic prostate cancer cells from chemotherapy-induced apoptosis. These data resulted in the development of a novel concept of an anti-survival factor therapy, namely an anti-IGF-1 therapy, which has provided encouraging preliminary data in a phase II clinical trial with terminally-ill hormone/chemotherapy-resistant prostate cancer patients.

Journal Article↗
PubMed1999

Repetitive and site-specific molecular staging of prostate cancer using nested reverse transcriptase polymerase chain reaction for prostate specific antigen and prostate specific membrane antigen.

We performed repetitive molecular staging using, nested rt-PCR for PSA and PSM at the peripheral blood (PB) and bone marrow (BM) of patients with prostate cancer (Pr.Ca) and benign prostate hyperplasia (BPH) after transrectal ultrasonography-guided biopsy (TRUS-B; 6-9 biopsies/patient), Pr.Ca patients after radical prostatectomy (RP), and Pr.Ca patients with diffuse bony metastases. All BPH patients (N = 20) tested negative at BM. Of the 2 who tested positive at PB 2 weeks after TRUS-B tested negative 8 weeks after TRUS-B. Of the 17 Pr.Ca, 7 (41.2%) tested positive at PB for PSA and PSM 2 weeks after TRUS-B while only 4 (23.5%) of them tested positive at repetitive analysis 8 weeks after TRUS-B. Two (11.8%) of the 17 Pr.Ca patients had positive analysis at BM for PSA and PSM 2 and 8 weeks after TRUS-B. Of 12 Pr.Ca patients with negative pre-operative molecular staging, 7 (58.3%) tested positive at PB for PSA and PSM 2 months post-RP but only 3 (25%) of them re-tested positive 12 months post-RP. Of these 12 Pr.Ca, 4 (33.3%) tested positive at BM for PSA and PSM 2 months post-RP while none re-tested positive 12 months post-RP. All Pr.Ca (N = 20) with diffuse bony lesions tested positive at BM. At PB, 6 of them (30%) tested negative for both PSA and PSM. Our data suggest that nested rt-PCR for PSA and PSM at PB is affected by TRUS-B and RP, while such analysis at BM concerted diffuse bony disease.

Adult↗
PubMed1999

Chemotherapy cytotoxicity of human MCF-7 and MDA-MB 231 breast cancer cells is altered by osteoblast-derived growth factors.

One-third of women with breast cancer will develop bone metastases and eventually die from disease progression at these sites. Therefore, we analyzed the ability of human MG-63 osteoblast-like cells (MG-63 cells), MG-63 conditioned media (MG-63 CM), insulin-like growth factor I (IGF-I), and transforming growth factor beta 1 (TGF-beta1) to alter the effects of adriamycin on cell cycle and apoptosis of estrogen receptor negative (ER-) MDA-MB-231 and positive (ER+) MCF-7 breast cancer cells, using cell count, trypan blue exclusion, flow cytometry, detection of DNA fragmentation by simple agarose gel, and the terminal deoxynucleotidyl transferase (TdT)-mediated nick end-labeling method for apoptosis (TUNEL assay). Adriamycin arrested MCF-7 and MDA-MB-231 cells at G2/M phase in the cell cycle and inhibited cell growth. In addition, adriamycin arrested the MCF-7 cells at G1/G0 phase and induced apoptosis of MDA-MB-231 cells. Exogenous IGF-I partially neutralized the adriamycin cytotoxicity/cytostasis of cancer cells. MG-63 CM and TGF-beta1 partially neutralized the adriamycin cytotoxicity of MDA-MB-231 cells but enhanced adriamycin blockade of MCF-7 cells at G1/G0 phase. MG-63 osteoblast-like cells inhibited growth of MCF-7 cells while promoting growth and rescued MDA-MB-231 cells from adriamycin apoptosis in a collagen co-culture system. These data suggest that osteoblast-derived growth factors can alter the chemotherapy response of breast cancer cells. Conceivably, host tissue (bone)-tumor cell interactions can modify the clinical response to chemotherapy in patients with advanced breast cancer.

Antineoplastic Agents↗
PubMed1998

Osteoblast-derived survival factors protect PC-3 human prostate cancer cells from adriamycin apoptosis.

OBJECTIVES: Hormone-independent and cytotoxic drug-resistant tumor growth in osteoblastic metastases defines poor survival in patients with advanced prostate cancer. Therefore, we analyzed the ability of human osteoblast-like cells (MG-63 cells) and MG-63 conditioned media (MG-63 CM) to protect PC-3 human prostate cancer cells from adriamycin cytotoxicity in vitro. METHODS: Adriamycin cytotoxicity was assessed in MG-63 osteoblast-like and PC-3 prostate cancer monolayer and three-dimensional collagen coculture systems using the DNA content and trypan blue exclusion assays, analysis of indexes of cell cycle by flow cytometry, determination of DNA fragmentation on simple agarose gel and terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) assay, and immunocytochemistry. RESULTS: Adriamycin (100 nM) arrested both the PC-3 and MG-63 cells at the G2/M phase in the cell cycle but induced apoptosis only in PC-3 cells, as assessed by flow cytometry, trypan blue exclusion, and agarose gel. Optimal doses of MG-63 CM (50 microg/mL), insulin-like growth factor I (50 ng/mL), and transforming growth factor-beta-1 (25 ng/mL), as determined by DNA content assay, partially neutralized the adriamycin cytotoxicity of PC-3 cells detected by flow cytometry and trypan blue exclusion. In addition, MG-63 cells rescued PC-3 cells from adriamycin apoptosis in the three-dimensional type I collagen gel coculture system, as analyzed by TUNEL assay. CONCLUSIONS: These data suggest that osteoblast-like cells and osteoblast-derived growth factors can optimize survival of metastatic prostate cancer cells, thereby helping to develop cytotoxic drug-resistant growth in vitro.

Biological Factors↗
PubMed1998

Effect of dehydroepiandrosterone on vaginal and uterine histomorphology in the rat.

Dehydroepiandrosterone (DHEA) applied on the dorsal skin of ovariectomized animals, at the twice daily dose of 30 mg, resulted in a complete reversal of the vaginal atrophy seen 1, 3 and 6 months after ovariectomy, and induced proliferation and mucification of the vaginal epithelium. A similar mucification of the vaginal epithelium related to androgenic action was observed in intact rats treated with DHEA. While treatment of intact rats with DHEA resulted in a significant increase in uterine weight at 1 month, the value of the same parameter decreased by approximately 30% after 3 and 6 months of DHEA administration. In ovariectomized DHEA-treated animals, uterine weight was increased at all time intervals. At histopathological examination, following DHEA administration to intact animals, stimulation was seen in the myometrial layers of the uterus whereas atrophy, involving especially the endometrium, became apparent after 3 and 6 months of treatment. In ovariectomized animals, the endometrium remained atrophic at all time intervals during DHEA treatment and the uterine epithelium thus remained atrophic under DHEA treatment. Examination of the effect of DHEA on the vaginal epithelium indicates that local application of DHEA on the vaginal mucosa is approximately 10-fold more efficient than application at a distant site on the skin. Reversal of the ovariectomy-induced increase in serum LH levels was also observed after DHEA treatment. The present data suggest that DHEA possesses a tissue-specific action, through its local transformation into active estrogens in the vaginal epithelium while the uterine epithelium remains atrophic. In addition, the site of administration of DHEA appears to be a significant factor, at least for its stimulatory effect on the vaginal mucosa.

Administration, Intravaginal↗
PubMed1998

Almost exclusive androgenic action of dehydroepiandrosterone in the rat mammary gland.

To determine the relative role of the androgenic and/or estrogenic components of the action of dehydroepiandrosterone (DHEA) on the histomorphology and structure of the rat mammary gland, ovariectomized (OVX) female animals received DHEA administered alone or in combination with the pure antiandrogen flutamide or the pure antiestrogen EM-800 for 12 months. We have also evaluated the effect of estradiol (E2) and dihydrotestosterone constantly released from SILASTIC brand silicon implants as well as medroxyprogesterone acetate released from poly(lactide-co-glycolide) microspheres. While 1-yr OVX resulted in a severe atrophy of the mammary gland, treatment of OVX animals with DHEA stimulated lobuloalveolar and ductal growth, as well as the secretory activity of the acinar cells, thus resulting in a lobuloalveolar type of development of the mammary gland. The addition of FLU to DHEA almost completely prevented the stimulatory effect observed with DHEA alone, whereas addition of the antiestrogen EM-800 had no significant effect on the action of DHEA on the mammary gland. At the doses used, medroxyprogesterone acetate and dihydrotestosterone also stimulated ductal and alveolar development, although to a lesser degree than that achieved with DHEA. The stimulatory effect of estradiol was mainly expressed on ductal growth with a smaller stimulatory effect on lobuloalveolar development. The above-indicated stimulatory effects on lobuloalveolar development were also reflected in significant increases of the total and parenchymal gland surface areas of the mammary gland. The present study shows that androgens induce a marked lobuloalveolar type of development of the mammary gland in the rat. Moreover, these data indicate the highly predominant or almost exclusive androgenic component in the potent stimulatory action of DHEA on the histomorphology and structure of the rat mammary gland. In fact, blockade of the potential estrogenic component of DHEA action by EM-800 did not affect the stimulatory action of DHEA on mammary gland histomorphology, whereas the antiandrogen FLU almost completely blocked the effect of DHEA.

Androgen Antagonists↗
PubMed1998

Effect of twenty-four-week treatment with the antiestrogen EM-800 on estrogen-sensitive parameters in intact and ovariectomized mice.

Treatment with the antiestrogen EM-800, at the daily oral dose of 3 microg, 10 microg, 30 microg, or 100 microg for 24 weeks, caused a marked inhibition of uterine and vaginal weight in both intact and ovariectomized mice. Maximal 64% and 41% inhibitions of uterine weight were achieved in intact and ovariectomized animals, respectively. Similar inhibitory effects of EM-800 were observed on vaginal weight with maximal inhibitions of 71% and 35%, in intact and ovariectomized animals, respectively. The pure antiestrogenic activity of EM-800 on the hypothalamo-pituitary-ovarian axis is illustrated by the 76-91% increases in ovarian weight observed in intact animals treated with the 10-100 microg doses of the antiestrogen. Serum 17beta-estradiol was 93% increased at the 100 microg daily dose of EM-800, whereas serum androstenedione, testosterone, and dihydrotestosterone were 141-713% increased over control at the same dose of the antiestrogen. Serum LH was increased by treatment with EM-800 in intact animals, whereas no effect was observed on the elevated gonadotropin levels in ovariectomized animals. At all doses used in intact animals, the antiestrogen caused a complete disappearance of the glandular elements of the mammary gland, the atrophy being comparable with that observed in ovariectomized mice. The mammary gland of EM-800-treated animals was exclusively composed of an atrophied ductal system lined by atrophied epithelial cells with an absence of lobulo-glandular elements. No effect of the compound was observed on the histology of the mammary gland in ovariectomized animals, thus showing the pure antiestrogenic effect of EM-800 on the mammary gland, as shown also for the uterus, vagina, and hypothalamo-pituitary axis. At histopathology, all doses of EM-800 in intact animals led to a moderate to severe uterine and vaginal atrophy. The uterine atrophy affected both the myometrium and the endometrium. Interestingly, the uterine atrophy achieved in intact animals treated with EM-800 was greater than that observed after ovariectomy alone, thus clearly demonstrating the pure antiestrogenic activity of EM-800. The present data show the highly potent and pure antiestrogenic activity of EM-800 on all parameters measured after 6 months of treatment in both intact and ovariectomized mice, a maximal effect being reached at the daily 10 microg dose of the antiestrogen in intact animals.

Androstenedione↗
PubMed1998

Predominant androgenic component in the stimulatory effect of dehydroepiandrosterone on bone mineral density in the rat.

In order to assess the relative roles of the androgenic and/or estrogenic components in the stimulatory effect of dehydroepiandrosterone (DHEA) on bone mineral content (BMC) and density (BMD), ovariectomized (OVX) female rats received DHEA administered alone or in combination with the antiandrogen flutamide (FLU) or the antiestrogen EM-800 for 12 months. We also evaluated, for comparison, the effect of estradiol (E2) and dihydrotestosterone (DHT) constantly released by Silastic implants as well as medroxyprogesterone acetate (MPA) released from poly(lactide-co-glycolide) microspheres. Femoral BMD was decreased by 11% 1 year after OVX, but treatment of OVX animals with DHEA increased BMD to a value 8% above that of intact animals. The administration of FLU reversed by 76% the stimulatory effect of DHEA on femoral BMD and completely prevented the stimulatory effect of DHEA on total body and lumbar spine BMD. Similar results were obtained for BMC. On the other hand, treatment with the antiestrogen EM-800 did not reduce the action of DHEA on BMD or BMC. At the doses used, MPA, E2 and DHT increased femoral BMD, but to a lesser degree than observed with DHEA. Bone histomorphometry measurements were also performed. While DHEA treatment partially reversed the marked inhibitory effect of OVX on the tibial trabecular bone volume, the administration of FLU inhibited by 51% (P < 0.01) the stimulatory effect of DHEA on this parameter. The addition of EM-800 to DHEA, on the other hand, increased trabecular bone volume to a value similar to that of intact controls. DHEA administration markedly increased trabecular number while causing a marked decrease in the intertrabecular area. The above stimulatory effect of DHEA on trabecular number was reversed by 54% (P < 0.01) by the administration of FLU, which also reversed by 29% the decrease in intertrabecular area caused by DHEA administration. On the other hand, the addition of EM-800, while further decreasing the intertrabecular space achieved by DHEA treatment, also led to a further increase in trabecular number to a value not significantly different from that of intact control animals, suggesting an additional effect of EM-800 over that achieved by DHEA. Treatment with DHEA caused a 4-fold stimulation of serum alkaline phosphatase, a marker of bone formation, while the urinary excretion of hydroxyproline, a marker of bone resorption, was decreased by DHEA treatment. Treatment with DHEA and DHEA + EM-800 decreased serum cholesterol levels by 22 and 65% respectively, while the other treatments had no significant effect on this parameter. The present data indicate that the potent stimulatory effect of DHEA on bone in the rat is mainly due to the local formation of androgens in bone cells and their intracrine action in osteoblasts.

Androgen Antagonists↗
PubMed1997

Comparative effects of 28-day treatment with the new anti-estrogen EM-800 and tamoxifen on estrogen-sensitive parameters in intact mice.

Following 28 days of oral administration, in intact mice, the novel non-steroidal anti-estrogen EM-800 was at least 30-fold more potent than tamoxifen in inhibiting uterine weight. Moreover, the maximal inhibitory effect achieved with tamoxifen on uterine weight was only 40% that with EM-800. The pure anti-estrogenic activity of EM-800 on the hypothalamo-pituitary-gonadal axis is illustrated by the increase in ovarian weight, while tamoxifen, due to its estrogenic activity, decreased ovarian weight. EM-800 is 10- to 30-fold more potent than tamoxifen in inhibiting uterine and vaginal estrogen receptors. Since 17beta-hydroxysteroid dehydrogenase (17beta-HSD) is the key enzyme in estradiol formation, the potent inhibitory effect of EM-800 on uterine 17beta-HSD could play an additional role by decreasing the availability of estradiol in the uterine tissue, while tamoxifen, on the contrary, stimulates activity of the enzyme. The atrophic changes in both the endometrial and myometrial layers achieved with EM-800 almost reached those observed 28 days after ovariectomy. EM-800 also resulted in a marked decrease in the number of ovarian developing follicles and corpora lutea, while the number of atretic follicles was increased. Tamoxifen treatment, on the other hand, produced an increase in both the number and crowding of the endometrial glands and a mild atrophy of the myometrial layer. Tamoxifen caused atrophic changes of the vaginal epithelium, especially at the highest doses, though the atrophy was much less pronounced than that following EM-800 treatment or ovariectomy. In addition to being at least 30-fold more potent than tamoxifen in inhibiting uterine weight, the novel anti-estrogen causes atrophy of the endometrium, stimulates the hypothalamo-pituitary-gonadal axis and inhibits uterine 17beta-HSD activity, while tamoxifen exerts opposite and estrogen-like effects on these parameters.

17-Hydroxysteroid Dehydrogenases↗
PubMed1997

Combined effects of dehydroepiandrosterone and EM-800 on bone mass, serum lipids, and the development of dimethylbenz(A)anthracene-induced mammary carcinoma in the rat.

Although treatment with dehydroepiandrosterone (DHEA) and the antiestrogen EM-800 alone decreased dimethylbenz(A)anthracene (DMBA)-induced mammary tumor incidence from 95% to 57% and 38%, respectively, approximately 9 months after DMBA administration, only two tumors developed in the group of animals that received the combination of DHEA and EM-800, and these two tumors disappeared before the end of the experiment (P < 0.01 vs. DHEA or EM-800 alone). Average tumor number per tumor-bearing animal as well as average tumor area per tumor-bearing animal were further decreased in animals that received the combination therapy compared with the effect of each treatment alone (P < 0.01). DHEA induced 6.9% (P < 0.01), 10.6% (P < 0.05), and 8.2% (P < 0.01) increases in bone mineral density of total skeleton, lumbar spine, and femur, respectively. The addition of EM-800 to DHEA did not affect the enhancing effect of DHEA on bone mass. The combination of the two drugs had important inhibitory effects on the urinary excretion of calcium and phosphorus as well as on the urinary hydroxyproline/creatinine ratio. Serum total alkaline phosphatase was stimulated by DHEA. Treatment with EM-800 decreased both serum triglyceride and cholesterol levels, whereas DHEA had an inhibitory effect on serum triglycerides. Although treatment with EM-800 caused a marked atrophy of the mammary gland, DHEA alone reduced lobular hyperplasia seen in aged intact rats while causing an androgen-specific stimulation of the same structures in animals already receiving the antiestrogen EM-800. The combination of DHEA and EM-800 lowered ovarian weight by 24% (P < 0.01) and decreased serum estradiol concentrations to intact control levels, whereas each compound alone had no effect on ovarian weight and stimulated serum estradiol levels by 45% (P < 0.05) and 46% (P < 0.05), respectively. Treatment with EM-800 caused a marked inhibition of uterine and vaginal weight. The present data show the additive inhibitory effects of DHEA and EM-800 on the development of DMBA-induced mammary carcinoma in the rat, thus suggesting the potential benefits of such a combination for the prevention of breast cancer in women while preserving or even increasing bone mass and maintaining a favorable lipid profile.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1997

Morphological changes induced by 6-month treatment of intact and ovariectomized mice with tamoxifen and the pure antiestrogen EM-800.

The present study compares the effects of tamoxifen and EM-800, both administered at the oral daily dose of 100 microg for 6 months, on the uterus, vagina, and mammary gland in the mouse at histopathological examination. Treatment of intact animals with EM-800 resulted in uterine and vaginal atrophy even greater than that achieved after ovariectomy, while the developmental growth of the mammary gland was completely blocked and serum LH was increased. In ovariectomized animals, treatment with EM-800 decreased uterine and vaginal wt below the values observed in control ovariectomized mice while no significant change was observed on serum LH, thus indicating the lack of estrogenic activity of EM-800. Tamoxifen, on the other hand, showed a stimulatory estrogenic-like action on the mouse uterus in both intact and ovariectomized animals, thus resulting in moderate to severe endometrial hyperplasia. These morphological changes were accompanied by a marked stimulation of both the estrogenic and androgenic 17beta-hydroxysteroid dehydrogenase as well as 5alpha-reductase uterine activities. The histological atrophic changes observed in the vagina after tamoxifen treatment were less pronounced than those seen after treatment with EM-800. The agonistic estrogen-like action of tamoxifen was also illustrated by the suppression of serum LH levels in ovariectomized animals. A marked stimulation of the ovarian stroma, accompanied by a significant reduction in folliculogenic activity, was observed after EM-800 or tamoxifen administration, although the interstitial ovarian hyperplasia was more pronounced after EM-800 treatment. While both antiestrogens blocked the developmental growth of the mammary gland, EM-800 showed more potent antiestrogenic activity than tamoxifen. The highly potent and specific antiestrogenic activity of EM-800 suggests that this compound could improve the therapy of breast cancer while avoiding the undesirable stimulation of the endometrium.

17-Hydroxysteroid Dehydrogenases↗
PubMed1996

Plasminogen activator inhibitor 1 messenger RNA expression and molecular evidence for del(7)(q22) in uterine leiomyomas.

We analyzed the expression of plasminogen activator inhibitor 1 (PAI-1) in 16 leiomyomas and adjacent myometrium of women who underwent a hysterectomy while in the proliferative (n = 8) and secretory phases (n = 8) of the menstrual cycle. We localized the PAI-1 and its mRNA expression in smooth muscle and vessel endothelial cells of uterine tissues using immunocytochemistry and in situ hybridization. The expression of PAI-1 mRNA was higher in 11 (68.75%) of 16 leiomyomas compared with the adjacent myometrium (leiomyoma/myometrium ratio, 1.4-3.0; mean, 2.045). The leiomyoma:myometrium ratio of PAI-1 mRNA expression did not change during the proliferative (Phase I) and secretory (Phase II) phases of the menstrual cycle. In the remaining five samples, the leiomyoma:myometrium ratio of PAI-1 mRNA expression was close to 1 (0.8-1.2; mean, 0.92). Because the locus of the PAI-1 gene is on chromosome 7q22, we screened for loss of heterozygosity (LOH) in these samples using the PAI-1 marker and D7S471, an anonymous marker 12 cM telomeric to PAI-1. Four of five samples with low leiomyoma:myometrium ratio had LOH for the PAI-1 and/or D7S471 markers. The fifth sample demonstrated a noninformative analysis for these markers but had LOH for the D7S515, D7S666, and D7S518 markers, all centromeric to PAI-1. Because del(7)(q22), associated with a relatively low PAI-1 mRNA expression, can deregulate matrix proteinases and growth factors' activity in leiomyomas, it is conceivable that del(7)(q22) results in heterogeneous leiomyoma biology.

Adult↗
PubMed1995

Purification and partial sequencing of the major mitogen for human uterine smooth muscle-like cells in leiomyoma extracts.

We purified the major mitogen for human smooth muscle-like cells in leiomyoma extracts by sequential liquid chromatography on (a) carboxymethyl-Sepharose, (b) heparin-Sepharose columns, (c) cartridges of C18 silica, and (d) linear gradient reverse-phase high performance liquid chromatography. The mitogenic activity of the leiomyoma extract throughout purification was tested by tritiated thymidine incorporation and DNA content in NIH/3T3 fibroblasts and KW human smooth muscle-like cells. Purification of the leiomyoma-derived growth factor (LDGF) for KW smooth muscle-like cells confirmed that its partial NH2-terminal amino acid (aa) sequence (1-20 aa) was identical to 113-132 aa of the human cysteine-rich protein (hCRP). A synthetic peptide which was engineered based on the purified aa sequence, stimulated the proliferation and growth of KW cells. An oligonucleotide probe constructed by the cDNA of the hcrp gene that encodes this aa sequence depicted the expression of 1.9-kb LDGF mRNA in leiomyomas and myometrium. The expression of the LDGF mRNA was three to sixfold higher in leiomyomas compared with adjacent myometrium of women harboring leiomyomas by in situ hybridization analysis. These data suggest that LDGF may participate in the pathophysiology of uterine leiomyomas.

3T3 Cells↗