Chaperoning of estrogen receptor and induction of mammary gland proliferation by neuronal protein synuclein gamma

Synucleins are emerging as central players in the formation of pathologically insoluble deposits characteristic of neurodegenerative diseases. However, synuclein gamma (SNCG), previously identified as a breast cancer specific gene (BCSG1), is also highly associated with breast cancer progression. Using transgenic mouse model, we demonstrated a role of SNCG in induction of highly proliferative pregnancy-like phenotype of mammary epithelial cells and branching morphology. SNCG participated in the heat shock protein-based multiprotein chaperone complex for steroid receptor signaling. Expression of SNCG in mammary epithelium resulted in a significant stimulation of ERalpha transcriptional activity. SNCG-induced mammary gland proliferation can be effectively blocked by antiestrogen and ovariectomy, indicating that the induced proliferation is mediated by ERalpha signaling and requires estrogen stimulation. These data indicate the chaperone activity of SNCG on stimulation of steroid receptor signaling in mammary gland and, thus induces extensive mammary gland proliferation and contributes to the hormonal impact on mammary tumorigenesis.

[Construction of multivalent DNA vaccine against Schistosoma japonicum]

OBJECTIVE

To construct a multivalent DNA vaccine.

METHODS

The multivalent DNA vaccine candidates pBK-Sj26-Sj23, pBK-Sj32-Sj23 were constructed based on the plasmids pBluescript-Sj26, pBluescript-Sj32 and pBluescript-Sj23 with three pairs of specific primers using DNA recombinant technique. In the primers, a synthetic linker sequence encoding a peptide was designed, and the antigen genes Sj26 and Sj23, Sj32 and Sj23 were then ligated. After identification, the quadriceps muscle of mice were immunized with the multivalent antigen genes. Four weeks after immunization, the multivalent antigen genes were present in the muscular tissue of mice by PCR.

RESULTS

The eukaryotic plasmids including multivalent antigens of S. japonicum were constructed successfully, and the plasmids including multivalent antigen gene could be stably existing in the muscle tissue of mice and the multivalent antigens could be expressed in the muscle tissue cells of mice.

CONCLUSION

A multivalent S. japonicum DNA vaccine has been established.

Inhibition of Wilms' tumor growth by intramuscular administration of tissue inhibitor of metalloproteinases-4 plasmid DNA

Extracellular matrix (ECM) degrading matrix metalloproteinases (MMPs) lead to ECM turnover, a key event in cancer growth and progression. The tissue inhibitors of matrix metalloproteinases (TIMPs) limit the activity of MMPs, which suggests their use for cancer gene therapy. Here we report that systemic administration of naked TIMP-4 DNA significantly inhibited Wilms' tumor growth in nude mice. TIMP-4, whose expression was lost in Wilms' tumor, inhibited the growth of G401 Wilms' tumor cells at a concentration lower than those required for MMP inhibition. This inhibition was associated with internalization of exogenous recombinant TIMP-4. Electroporation-mediated intramuscular injection of TIMP-4 expression plasmid resulted in sustained plasma TIMP-4 levels and significant tumor suppression. Our data demonstrate a tumor suppressive effect of TIMP-4 against Wilms' tumor and the potential utility of intramuscular delivery of TIMP gene for treatment of kidney derived cancers.

An epidemiological investigation of congenital Schistosoma japonicum transmission in Hubei Province, PR China

A cohort study was conducted in Hubei Province, China, following serious flooding of the Yangtze River in the autumn of 1998 to investigate the possibility of congenital transmission of Schistosoma japonicum in humans. The cohort investigated was comprised of 205 women and their 208 infants born between 1 September and 30 December 1998. Blood and fecal samples from all the women and their infants were collected and examined for S. japonicum infection. Positive specific antibody titers were found in 14 (6.8%) of the mothers, but no fecal egg excretion was observed. All infants had negative specific antibody titers and no S. japonicum eggs were found in their feces. Hence, the present study coud not confirm congenital S. japonicum transmission in humans. Further studies are highly wanted to study the impact of prenatal exposure of S. japonicum on the offspring.

Stimulation of mammary tumorigenesis by systemic tissue inhibitor of matrix metalloproteinase 4 gene delivery

Tissue inhibitors of matrix metalloproteinase (TIMPs) are multifunctional proteins with both matrix metalloproteinase (MMP) inhibitory effects and growth-regulatory activity. TIMPs inhibit MMP activity, suggesting a use for cancer gene therapy. However, here we report that systemic administration of human TIMP-4 by electroporation-mediated i.m. injection of naked TIMP-4 DNA stimulates tumorigenesis of human breast cancer cells in nude mice. Consistent with tumor stimulation, TIMP-4 up-regulates Bcl-2 and Bcl-X(L) protein. TIMP-4 also inhibits apoptosis in human breast cancer cells in vitro and mammary tumors in vivo. A synthetic MMP inhibitor BB-94 did not have such antiapoptotic effect. Analysis of TIMP-4 expression in human mammary specimens indicates that TIMP-4 protein is increased in mammary carcinoma cells compared with normal mammary epithelial cells. These data indicate an antiapoptotic activity in breast cancer cells and a tumor-stimulating effect of TIMP-4 when administrated systemically.

Development and characterization of a new polyclonal antibody specifically against tissue inhibitor of metalloproteinases 4 in human breast cancer

Tissue inhibitors of metalloproteinases (TIMPs) may regulate extracellular matrix turnover and cellular functions by modulating matrix metalloproteinase (MMP) activity and cell proliferation and apoptosis. To investigate the locations and functions of TIMP-4 in human breast cancer, a highly specific polyclonal anti-TIMP-4 peptide antibody (pAb-T4-S61) was developed. The potency and specificity of the purified IgG were characterized by an enzyme-linked immunosorbent assay, immunoblot, and immunohistochemistry. The optimal IgG concentration range was 0.1-10 microg/ml. pAb-T4-S61 did not cross-react with TIMP-1 and TIMP-2 and should not react with TIMP-3 according to the sequence analysis. Parental MDA-MB-435 breast cancer cells were TIMP-4 negative and a TIMP-4 transfected clone, TIMP-4-435-12, produced TIMP-4. Membrane type-1 MMP was detected although TIMP-2 was not found in these cells. Interestingly, the TIMP-4 protein was detected by immunohistochemical staining in infiltrating breast carcinoma cells in tumor tissues. Thus, pAb-T4-S61 is a useful tool to investigate expression patterns and functions of TIMP-4 in cancers.

Induction of mammary differentiation by mammary-derived growth inhibitor-related gene that interacts with an omega-3 fatty acid on growth inhibition of breast cancer cells

We previously identified and characterized a novel tumor growth inhibitor and a fatty acid-binding protein in human mammary gland and named it the mammary-derived growth inhibitor-related gene (MRG). Here, the effects of MRG on mammary gland differentiation and its interaction with omega-3 polyunsaturated fatty acids (omega-3 PUFAs) on growth inhibition were investigated. MRG protein expression was associated with human mammary gland differentiation, with the highest expression observed in the differentiated alveolar mammary epithelial cells from the lactating gland. Overexpression of MRG in human breast cancer cells induced differentiation with changes in cellular morphology and a significant increase in the production of lipid droplets. Treatment of mouse mammary gland in organ culture with MRG protein resulted in a differentiated morphology and stimulation of beta-casein expression. Treatment of human breast cancer cells with the omega-3 PUFA docosahexaenoic acid resulted in a differential growth inhibition proportional to their MRG expression. MRG-transfected cells or MRG protein treated cells were much more sensitive to docosahexaenoic acid-induced growth inhibition than MRG-negative or untreated control cells. Our results suggest that MRG is a candidate mediator of the differentiating effect of pregnancy on breast epithelial cells and may play a major role in omega-3 PUFA-mediated tumor suppression.

Pathology and course of natural Schistosoma japonicum infection in pigs: results of a field study in Hubei province, China

In order to obtain information on the natural course of porcine infection with Schistosoma japonicum, pigs were exposed to the cercariae of this parasite in a highly endemic region of China. Five, 5-month-old pigs previously infected with S. japonicum (group A) and 10, schistosome-naïve piglets (group B) were allowed on a pasture infested with Oncomelania snails for one transmission period (approximately 5.5 months). All the piglets rapidly acquired infection, and both groups remained infected throughout the study period. Group B showed fever, diarrhoea and anorexia in the early egg-excretion phase, and marked growth reduction. In both groups, post-mortem examination revealed live schistosomes and lesions associated with dead worms in the intestinal and mesenteric vasculature, and egg-related pathology in the large intestine and liver. Major findings were exudative lesions connected with egg excretion in the intestine, and granulomatous obstruction of portal veins in the liver. Signs of granuloma modulation were found in the liver, but not in the intestine. In conclusion, the study showed that field exposure of pigs to S. japonicum for one transmission period resulted in clinical disease and growth retardation in the youngest pigs, and significant pathology in both groups. Self cure, prominent in experimental porcine infections produced with single, high-dose inocula, was not induced in either group.

Transcriptional suppression of synuclein gamma (SNCG) expression in human breast cancer cells by the growth inhibitory cytokine oncostatin M

Previously, we have shown that synuclein gamma (SNCG), a member of the brain protein synuclein family, is highly expressed in human infiltrating breast carcinomas but not expressed in normal or benign breast tissues. The SNCG mRNA was also detected in several human breast cancer cell lines with the highest expression found in H3922, a cell line derived from an infiltrating ductal carcinoma. In this study, we show that expression of SNCG mRNA in H3922 cells is significantly decreased by treating cells with the cytokine oncostatin M (OM) who has a growth-inhibitory effect on these cells. A decrease in SNCG mRNA level can be detected as early as 30 min after OM addition. By 4 h OM treatment, the level of SNCG mRNA was decreased to 70% of control, and by 24 h the mRNA was below detectable level. Western blot analysis further demonstrated the suppression of SNCG protein expression by OM. The level of SNCG protein in H3922 cells was reduced more than 90% by OM after 2 days. Since OM-induced growth inhibition occurs after 3-4 days, the down-regulation of SNCG expression appears to proceed the effect of OM on cell growth. Additional experiments to measure the transcriptional rates of SNCG indicate that the observed OM-induced down-regulation of SNCG mRNA occurs mainly at the transcriptional level. In an attempt to examine the role of SNCG gene in the proliferation of breast cancer cells, SNCG cDNA was stably transfected into MCF-7 cells that do not express endogenous SNCG gene. Examination of cell growth under anchorage-dependent and anchorage-independent conditions demonstrates that over expression of SNCG gene significantly stimulated the growth of MCF-7 cells both in monolayer culture and in soft agar. These data together suggest that SNCG may play a role in cell proliferation.

Suppression of breast cancer growth and metastasis by a serpin myoepithelium-derived serine proteinase inhibitor expressed in the mammary myoepithelial cells

A serpin was identified in normal mammary gland by differential cDNA sequencing. In situ hybridization has detected this serpin exclusively in the myoepithelial cells on the normal and noninvasive mammary epithelial side of the basement membrane and thus was named myoepithelium-derived serine proteinase inhibitor (MEPI). No MEPI expression was detected in the malignant breast carcinomas. MEPI encodes a 405-aa precursor, including an 18-residue secretion signal with a calculated molecular mass of 46 kDa. The predicted sequence of the new protein shares 33% sequence identity and 58% sequence similarity to plasminogen activator inhibitor (PAI)-1 and PAI-2. To determine whether MEPI can modulate the in vivo growth and progression of human breast cancers, we transfected a full-length MEPI cDNA into human breast cancer cells and studied the orthotopic growth of MEPI-transfected vs. control clones in the mammary fat pad of athymic nude mice. Overexpression of MEPI inhibited the invasion of the cells in the in vitro invasion assay. When injected orthotopically into nude mice, the primary tumor volumes, axillary lymph node metastasis, and lung metastasis were significantly inhibited in MEPI-transfected clones as compared with controls. The expression of MEPI in myoepithelial cells may prevent breast cancer malignant progression leading to metastasis.

TIMP-4 is regulated by vascular injury in rats

The role of basement membrane-degrading matrix metalloproteinases (MMPs) in enabling vascular smooth muscle cell migration after vascular injury has been established in several animal models. In contrast, the role of their native inhibitors, the tissue inhibitors of matrix metalloproteinases (TIMPs), has remained unproven despite frequent coregulation of MMPs and TIMPs in other disease states. We have investigated the time course of expression and localization of TIMP-4 in rat carotid arteries 6 hours, 24 hours, 3 days, 7 days, and 14 days after balloon injury by in situ hybridization, immunohistochemistry, and Western blot analysis. TIMP-4 protein was present in the adventitia of injured carotid arteries from 24 hours after injury. At 7 and 14 days after injury, widespread immunostaining for TIMP-4 was observed throughout the neointima, media, and adventitia of injured arteries. Western blot analysis confirmed the quantitative increase in TIMP-4 protein at 7 and 14 days. In situ hybridization detected increased expression of TIMP-4 as early as 24 hours after injury and a marked induction in neointimal cells 7 days after injury. We then studied the effect of TIMP-4 protein on the migration of smooth muscle cells through a matrix-coated membrane in vitro and demonstrated a 53% reduction in invasion of rat vascular smooth muscle cells. These data and the temporal relationship between the upregulation of TIMP-4, its accumulation, and the onset of collagen deposition suggest an important role for TIMP-4 in the proteolytic balance of the vasculature controlling both smooth muscle migration and collagen accumulation in the injured arterial wall.

Stimulation of breast cancer invasion and metastasis by synuclein gamma

We recently identified and cloned novel breast cancer-specific gene BCSG1 by direct differential cDNA sequencing. BCSG1 has a great sequence homology with the Alzheimer's disease related neural protein synuclein (SNC); thus, it was also named SNC-gamma. Overexpression of SNC-gamma in breast cancer cells leads to a significant increase in motility and invasiveness in vitro and a profound augmentation of metastasis in vivo. Our data suggest that this member of the neural protein SNCs might have important functions outside the central nervous system and may play a role in breast cancer progression.

RIZ1, but not the alternative RIZ2 product of the same gene, is underexpressed in breast cancer, and forced RIZ1 expression causes G2-M cell cycle arrest and/or apoptosis

The retinoblastoma protein-interacting zinc finger gene RIZ maps to the distal short arm of human chromosome 1 (1p36), a region thought to harbor tumor suppressor genes for a variety of human cancers including breast cancer. The RIZ gene normally produces two protein products of different length, RIZ1 and RIZ2. RIZ2 is generated by an internal promoter and lacks an NH2-terminal motif of RIZ1, the PR domain conserved in a subfamily of zinc finger genes that function as negative regulators of tumorigenesis. We have here studied whether the RIZ gene may play a role in human neoplasia. We found that expression of RIZ1 is commonly decreased or at undetectable levels in breast cancer tissues and cell lines. Decreased RIZ1 expression was also found in other tumor types including neuroblastoma and lung cancer. Remarkably, RIZ2 is normally expressed in all cases examined, suggesting that the abnormality observed for RIZ1 is specific. Forced RIZ1 expression in breast cancer cells caused cell cycle arrest in G2-M and/or programmed cell death. These observations suggest an exclusive negative selection for RIZ1 but not RIZ2 in breast cancer and a role for RIZ1 in tumor suppression.

Preparation and characterization of recombinant tissue inhibitor of metalloproteinase 4 (TIMP-4)

TIMP-4, a novel human tissue inhibitor of metalloproteinase, was identified and cloned (Greene, J., Wang, M., Raymond, L. A., Liu, Y. E., Rosen, C., and Shi, Y. E. (1996) J. Biol. Chem. 271, 30375-30380). In this report, the production and characterization of recombinant TIMP-4 (rTIMP4p) are described. rTIMP4p, expressed in baculovirus-infected insect cells, was purified to homogeneity by a combination of cation exchange, hydrophobic, and size-exclusion chromatographies. The purified protein migrated as a single 23-kDa band in SDS-polyacrylamide gel electrophoresis and in Western blot using a specific anti-TIMP-4 antibody. Inhibition of matrix metalloproteinase (MMP) activities by rTIMP4p was demonstrated in five MMPs. Enzymatic kinetic studies revealed IC50 values (concentration at 50% inhibition) of 19, 3, 45, 8, and 83 nM for MMP-1, MMP-2, MMP-3, MMP-7, and MMP-9, respectively. Purified rTIMP4p demonstrated a strong inhibitory effect on the invasion of human breast cancer cells across reconstituted basement membranes. Thus, TIMP-4 is a new enzymatic inhibitor in MMP-mediated extracellular matrix degradation and may have therapeutic potential in treating cancer malignant progression.

Antitumor activity of the novel human breast cancer growth inhibitor, mammary-derived growth inhibitor-related gene, MRG

A novel human tumor growth inhibitor was identified by differential cDNA sequencing. The predicted amino acid sequence of this tumor-suppressing factor has a significant sequence homology to mouse mammary-derived growth inhibitor and thus was named mammary-derived growth inhibitor-related gene (MRG). MRG was found to be expressed in normal and benign human breast tissues but not in breast carcinomas. In situ hybridization analysis demonstrated a stage-specific MRG expression as follows. MRG was barely detectable in breast carcinomas, showed partial and weak expression in benign hyperplasia, but was expressed at a high level in normal breast epithelial cells. To determine if MRG can modulate in vivo growth of human breast cancers, we transfected a full-length MRG cDNA into MDA-MB-231 human breast cancer cells and studied the orthotopic growth of MRG transfectants versus control transfectants in the mammary fat pad of athymic nude mice. Overexpression of MRG in human breast cancer cells significantly suppressed cell proliferation in vitro and tumor growth in an orthotopic nude mouse model. These results suggest that MRG has tumor-suppressing activity, and the loss of MRG expression may be involved in the development and progression of breast cancer.

Specific, high affinity binding of tissue inhibitor of metalloproteinases-4 (TIMP-4) to the COOH-terminal hemopexin-like domain of human gelatinase A. TIMP-4 binds progelatinase A and the COOH-terminal domain in a similar manner to TIMP-2

The binding properties of the newly described tissue inhibitor of metalloproteinases-4 (TIMP-4) to progelatinase A and to the COOH-terminal hemopexin-like domain (C domain) of the enzyme were examined. We present evidence for the first time of a specific, high affinity interaction between TIMP-4 and the C domain of human gelatinase A and show that TIMP-4 binds both progelatinase A and the C domain in a similar manner to that of TIMP-2. Saturable binding of recombinant C domain to TIMP-4 and to TIMP-2 but not to TIMP-1 was demonstrated using a microwell protein binding assay. The recombinant collagen binding domain of gelatinase A, comprised of the three fibronectin type II-like repeats, did not bind to TIMP-4, indicating that binding is mediated selectively by the C domain. Binding to TIMP-4 was of high affinity with an apparent Kd of 1.7 x 10(-7) M but slightly weaker than that to TIMP-2 (apparent Kd of 0.66 x 10(-7) M). Affinity chromatography confirmed the TIMP-4-C domain interaction and also showed that the complex could not be disrupted by 1 M NaCl or 10% dimethyl sulfoxide, thereby further demonstrating the tight binding. To verify the biological significance of this interaction, binding of full-length progelatinase A to TIMP-4 was investigated. TIMP-4 and TIMP-2 but not TIMP-1 bound specifically to purified TIMP-2-free human recombinant full-length progelatinase A and to full-length rat proenzyme from the conditioned culture medium of ROS 17/2.8 cells. Preincubation of the C domain with TIMP-2 was found to reduce subsequent binding to TIMP-4 in a concentration-dependent manner. Competition between TIMP-2 and TIMP-4 for a common or overlapping binding sites on the gelatinase A C domain may occur; alternatively TIMP-2 may prevent the binding of TIMP-4 by steric hindrance or induction of a conformational change in the C domain. We propose that the binding of progelatinase A to TIMP-4 represents a third TIMP-progelatinase interaction in addition to that of progelatinase A with TIMP-2 and progelatinase B with TIMP-1 described previously. This new phenomenon may be of important physiological significance in modulating the cell surface activation of progelatinase A.

Inhibition of tumor growth and metastasis of human breast cancer cells transfected with tissue inhibitor of metalloproteinase 4

We recently identified, cloned, and characterized a novel human tissue inhibitor of metalloproteinases-4, TIMP-4 (Greene et al., 1996). To determine if TIMP-4 can modulate the in vivo growth of human breast cancers, we transfected a full-length TIMP-4 cDNA into MDA-MB-435 human breast cancer cells and studied the orthotopic growth of TIMP-4-transfected (TIMP4-435) versus control (neo-435) clones in the mammary fat pad of athymic nude mice. TIMP4-435 clones expressed TIMP-4 mRNA and produced anti-metalloproteinase (MMP) activity, while neo-435 clones did not express TIMP-4 mRNA or produce detectable anti-MMP activity. Overexpression of TIMP-4 inhibited the invasion potential of the cells in the in vitro invasion assay. When injected orthotopically into nude mice, TIMP-4 transfectants were significantly inhibited in tumor growth by 4-10-fold in primary tumor volumes; and in an axillary lymph node and lung metastasis as compared with controls. These results suggest the therapeutic potential of TIMP-4 in treating cancer malignant progression.

Computational sequence analysis of the tissue inhibitor of metalloproteinase family

The tissue inhibitor of metalloproteinase (TIMP) family regulates extracellular matrix turnover and tissue remodeling by forming tight-binding inhibitory complexes with matrix metalloproteinases (MMPs). MMPs and TIMPs have been implicated in many normal and pathological processes, such as morphogenesis, development, angiogenesis, and cancer metastasis. This minireview provides information that would aid in classification of the TIMP family and in understanding the similarities and differences among TIMP members according to the physical data, primary structure, and homology values. Calculations of molecular weight, isoelectric point values, and molar extinction coefficients are reported. This study also compares sequence similarities and differences among the TIMP members through calculations of homology within their individual loop regions and the mature region of the molecule. Lastly, this report examines structure-function relationships of TIMPs. Thorough knowledge of TIMP primary and tertiary structure would facilitate the uncovering of the molecular mechanisms underlying metalloproteinase, inhibitory activities and biological functions of TIMPs.

Identification of a breast cancer-specific gene, BCSG1, by direct differential cDNA sequencing

A high-throughput direct-differential cDNA sequencing approach was employed to identify genes differentially expressed in normal breast as compared with breast cancer. Approximately 6000 expressed sequence tags (ESTs) from cDNA libraries of normal breast and breast carcinoma were selected randomly and subjected to EST-sequencing analysis. The relative expression levels of more than 2000 unique EST groups were quantitatively compared in normal versus cancerous breast. Of many putative differentially expressed genes, a breast cancer-specific gene, BCSGC1, which was expressed in high abundance in a breast cancer cDNA library but scarcely in a normal breast cDNA library, was identified as a putative breast cancer marker. In situ hybridization analysis demonstrated stage-specific BCSG1 expression as follows: BCSG1 was undetectable in normal or benign breast lesions, showed partial expression in ductal carcinoma in situ, but was expressed at an extremely high level in advanced infiltrating breast cancer. The predicted amino acid sequence of BCSG1 gene has a significant sequence homology to the non-amyloid beta protein fragment of the Alzheimer's disease amyloid protein. BCSG1 overexpression may indicate breast cancer malignant progression from benign breast or in situ carcinoma to the highly infiltrating carcinoma.

Molecular cloning and characterization of human tissue inhibitor of metalloproteinase 4

The tissue inhibitors of metalloproteinases (TIMPs) constitute a family of proteins, of which three members have so far been described. Using the expressed sequence tag sequencing approach, we have identified a novel TIMP-related cDNA fragment and subsequently cloned a fourth human TIMP (TIMP-4) from a human heart cDNA library. The open reading frame encodes a 224-amino acid precursor including a 29-residue secretion signal. The predicted structure of the new protein shares 37% sequence identity with TIMP-1 and 51% identity with TIMP-2 and -3. The protein has a predicted isoelectric point of 7.34. The open reading frame-directed expression of TIMP-4 protein in MDA-MB-435 human breast cancer cells showed metalloproteinase inhibitory activity on reverse zymography. By Northern analysis, only the adult heart showed abundant TIMP-4 transcripts with a 1. 4-kilobase predominant transcript band; very low levels of the transcripts were detected in the kidney, placenta, colon, and testes, and no transcripts were detected in the liver, brain, lung, thymus, and spleen. This unique expression pattern suggests that TIMP-4 may function in a tissue-specific fashion in extracellular matrix homeostasis.

Schistosoma japonicum and S. mansoni: comparison of larval migration patterns in mice

Mice were infected percutaneously with cercariae of Schistosoma japonicum or S. mansoni and parasites recovered by tissue-mincing from the skin or lungs or by perfusion of the mesenteric veins. S. japonicum had a narrow peak of recovery (up to 30%) from the lungs 3 days after infection, whereas lung recovery of S. mansoni peaked only on day 6 and levelled off during the following week. Infection with S. japonicum induced lung petechiae, but only after most of the parasites had left the lungs. The axillary lymph nodes draining the infection site increased in weight after infection and this effect was much greater and longer with S. mansoni than with S. japonicum. S. japonicum was perfusable from the mesenteric veins earlier (from day 3 onwards) and in higher number (40-60% from days 6 to 10) than S. mansoni (20% on day 20). The percentage of cercariae developing to adult worms was 57% for S. japonicum and 33% for S. mansoni. The data demonstrate that S. japonicum might escape from local tissue reactions in the skin and lungs and, due to its rapid migration, might induce only poor lymphocyte proliferation. As a possible consequence, S. japonicum may establish more efficiently in mice than S. mansoni.

Progestins and antiprogestins in mammary tumour growth and metastasis

Growth of the normal mammary gland involves proliferation, differentiation, programmed cell death and remodelling of the basement membrane throughout the cyclic ovarian stimulation of the menstrual cycle and the pregnancy/lactation cycle. The regulation of these processes involves a balance between the actions of oestrogen and progesterone. Although it is generally accepted that oestrogens are the major adverse hormonal factor in onset and progression of human breast cancer, recent studies suggest that progesterone and its synthetic progestins may be more important than oestrogen as an ovarian stimulus in driving proliferation of normal human and rodent mammary epithelium. One might expect that some aspects of these complex progestin-regulated events might be retained in breast cancer. This review focuses on evidence that progesterone has proliferative actions in breast cancers; on the role of progestins in regulation of metastasis-related adhesion molecules on breast cancer cells and on the preliminary data showing that progesterone antagonists may be powerful new tools for the management of metastastic breast cancer. This evidence suggests that progesterone is a stimulus for onset and progression of breast tumours and that antiprogestins can interrupt these processes.

Matrix-degrading proteases in hormone-dependent breast cancer

Proteases have emerged as important modulators of the metastatic capacity of cancer. However, metastasis is regulated by multiple other characteristics of the tumor cell and evidence suggests the participation of multiple classes of proteases. In the present article we review the literature concerning the potential biological roles of multiple proteases in breast cancer. In particular, we focus on the gelatin-degrading metallo proteinase and on a novel 80 KDa matrix-degrading protease that appears to be commonly expressed in hormone dependent breast cancer cell lines.

BCG vaccination in deer: distinctions between delayed type hypersensitivity and laboratory parameters of immunity

Groups of deer were vaccinated with live or killed Bacillus Calmette-Guerin (BCG), with and without oil adjuvant, to compare their immune responses with those found in naturally infected animals. Killed BCG in oil induced strong lymphocyte transformation (LT) and antibody (ELISA) responses specific for Mycobacterium bovis antigens. Serum inflammatory proteins (SIP) were also induced after these animals were skin tested. This pattern of reactivity mirrored that found in naturally infected deer with active tuberculosis. Animals vaccinated with live BCG without oil adjuvant also produced strong LT reactivity but this was directed at common mycobacterial antigens found on both M. bovis and M. avium, although no antibody or SIP were detected at any stage of the experiment. The pattern of immune responsiveness to live BCG was similar to that found in naturally infected, but non-diseased deer, and may represent the immunoprotective response to tuberculosis. Significant differences in specificity of lymphocyte transformation and intradermal skin test reactivity to mycobacterial antigens were also identified. Vaccination with BCG in various formulations provides an experimental probe to evaluate the immunological basis of immunity to tuberculosis.

Pharmacokinetic study of RU 486 and its metabolites after oral administration of single doses to pregnant and non-pregnant women

RU 486 and three of its metabolites (RU 42633-monodemethyl, RU 42848-didemethyl, and RU 42698-hydroxymetabolite) were determined by HPLC in plasma from nine non-pregnant and 36 pregnant women. Each non-pregnant subject took an oral dose of RU 486 (25, 100, 400 and 600 mg consecutively) once per menstrual cycle. Six of the nine women also received a dose of 200 mg. The 36 pregnant women were randomized into four groups which were given a single dose of 25, 100, 400 or 600 mg RU 486. Blood samples were taken up to 120 h after dosing. Peak concentrations of RU 486 occurred on most occasions within 2 h. Plasma concentrations at 1 h and at 24 h increased in proportion to log dose. There was a wide variability (up to ten-fold) in the pharmacokinetic parameters within each dose group. Plasma concentrations of RU 42633 were similar to those of RU 486 but concentrations of RU 42848 and RU 42698 were much lower. As with RU 486, the plasma concentrations of the metabolites were maintained at high levels for up to 48-72 h after dosing. The findings were consistent with a rapid metabolism of RU 486 to RU 42633; removal of the second methyl group leading to RU 42698 occurred much more slowly and to a much less extent than removal of the first. There appeared to be no significant differences between the non-pregnant and pregnant women in either the plasma concentrations or pharmacokinetic parameters of RU 486 and its metabolites.

Immunization of pigs against infection with Schistosoma japonicum using ultraviolet-attenuated cercariae

Since pigs are important in the zoonotic transmission of schistosomiasis japonica in China, a veterinary vaccine might contribute to the control of the disease in humans. Pigs were immunized with three doses each of 10,000 cercariae of Schistosoma japonicum attenuated with ultraviolet light (400 microWatt.min/cm2). The experiment was performed with portable irradiation equipment in a rural area of the Hubei Province (P.R. China). A challenge infection of 1,000 untreated cercariae was given 2.5 or 6 months after the last immunization, and age-matched naive pigs were challenged as a control. Immunized pigs developed about 90% resistance against the challenge. The liver egg load of these animals was reduced by over 90%. Less than 0.01% of the immunizing cercariae developed to adult parasites and the vaccination had no apparent adverse influence on the pigs' health.

Expression of 67 kDa laminin receptor in human breast cancer cells: regulation by progestins

The level of 67 kDa laminin receptor (67LR) expression on breast and colon tumor cell surfaces was previously shown to be correlated with the capacity of tumor cells to metastasize. In the present work we investigate the effects of progestins and estrogen on the expression of 67LR in two sublines of the T47D human breast cancer cells: weakly tumorigenic, poorly invasive parental T47D cells and a highly tumorigenic, more invasive T47Dco subclone. Immunoblotting with an affinity purified antibody directed against a synthetic peptide recognizes the 67LR in these cells. 67LR expression in the T47Dco subclone is 5.5-fold higher than in their parental T47D cells. Treatment of T47D cells with 1 nM of the synthetic progestin R5020 results in a 4-fold increase in 67LR protein expression. Estrogen also induced 67LR expression, but only by 1.5-fold. The progestin-stimulated expression of the 67LR correlates with a 4.3-fold increase in attachment of T47D cells to laminin. A monoclonal antibody, mAb 13, directed against beta 1 integrin, completely blocks the attachment of T47D cells to fibronectin, only partially inhibits the attachment of T47D cells to laminin, and appears not to affect the progestin-stimulated laminin attachment of T47D cells. A new antiprogestin, ZK 112.993, significantly inhibits both progestin-stimulated 67LR expression and the increased attachment to laminin. These results suggest a possible role for progestin in mediating one of the multiple events thought to be important in metastasis of steroid receptor positive human breast cancer cells.

Identification and characterization of a novel matrix-degrading protease from hormone-dependent human breast cancer cells

A novel matrix-degrading enzyme was identified from human breast cancer cells. This enzyme appears as major gelatinase in hormone-dependent breast cancer cell lines and has as an apparent molecular mass of 80 kDa on gelatin zymography. The 80-kDa enzyme has a unique metal ion specificity. In addition to calcium ions, the gelatinolytic activity can be supported by manganese and/or magnesium. Unlike 92- and 72-kDa gelatinases and other known members of the metalloproteinase family, the 80-kDa protease is not activated by p-aminophenylmercuric acetate and its gelatinolytic activity is not inhibited by tissue inhibitor of metalloproteinase 2. It is active over the pH range 7.5-9.5 with an optimum at pH 8.5. The enzyme degrades gelatin and type IV collagen. The proteolytic activity of the enzyme is inhibited by EDTA and leupeptin. These unique features clearly distinguish the 80-kDa protease from the known 92-and 72-kDa gelatinases. The expression of 80-kDa enzyme can be detected in hormone-dependent human breast cancer cell lines in vitro and in tumors grown from these cells in athymic nude mice.

[Purification of 31/32 kDa proteins of adult Schistosoma japonicum and studies on their protective immunity]

Schistosoma japonicum adult worm 31/32 kDa proteins (Sj 31/32) were separated on polyacrylamide slab gels and purified by electrophoretic elution. These purified proteins were used to immunize mice in order to observe their protective immunity against challenge. The results of SDS-PAGE,EITB and ELISA indicated that the 31/32 kDa proteins separated and purified by means of these methods were pure and active. It was assumed that Sj 31/32 proteins could reduce worm burden and inhibit the fecundity of schistosome and formation of egg granuloma. The results suggested that 31/32 kDa S. japonicum proteins might be an important component of a multivalent vaccine against schistosomiasis japonica (Figs. 1-4).

Reactivity of Schistosoma japonicum and S. mansoni antigen preparations in indirect haemagglutination (IHA) with sera of patients with homologous and heterologous schistosomiasis

Sera of patients infected with Schistosoma japonicum, S. mansoni or S. haematobium were tested in an indirect haemagglutination assay (IHA) using soluble S. japonicum egg antigen (SjSEA) and soluble S. mansoni adult antigen prepared either from a Puerto Rican strain (SmAWA) or an Egyptian strain (SmBW; Cellognost-Schistosomiasis Kit). Reactions were best, in terms of titres and sensitivity, in homologous systems. Heterologous systems were less reliable, particularly those using sera from urinary schistosomiasis patients. It is suggested that IHA is a suitable test to detect Schistosoma infections, especially when homologous systems are used.

Schistosoma mansoni and S. japonicum: decline of antibodies against diagnostic adult worm antigens (Sm31/32) following praziquantel treatment of mice

Mice were infected with 10, 100 or 200 cercariae of Schistosoma mansoni or S. japonicum and treated between one and two months later with two doses of praziquantel. At this time, the animals had high levels of antibodies against the adult worm proteins Sm31/32 (schistosome cathepsin B and haemoglobinase). Antibody levels were followed up for about one more year by Western blots and ELISA using purified Sm31/32. Among the 34 surviving mice perfused at the end of the experiments, 14 had between 1 and 4 and one mouse had 8 residual stunted worms. In most mice without detectable worms, anti-Sm31/32 antibodies started to drop within a few months after therapy. In other animals of this group and in those harbouring residual worms, the decrease in titers was not observed or less pronounced. Thus, the presence of even one stunted worm was sufficient to induce continued high titres of antibodies. Decreasing levels of antibody against Sm31/32, however, reflected complete elimination of schistosomes.

A multicenter clinical study on two types of levonorgestrel tablets administered for postcoital contraception

Contraceptive efficacy, cycle control and side effects of two types of 0.75 mg levonorgestrel tablets taken postcoitally during the periovulatory period of one cycle were studied in a multicenter trial involving 361 women. No significant differences were found between the two types of levonorgestrel pills in terms of contraceptive efficacy, cycle control and side effects. The failure rate observed (1.4% per treated cycle) was similar to that reported for other hormonal approaches to emergency postcoital contraception. Intermenstrual bleeding or spotting occurred in 11.5% of the cycles and anovulation as assessed from BBT charts in 14.4% of cycles. One or more side effects were reported by 22.2% of subjects. The relatively frequent occurrence of cycle disturbances and subjective side effects make it unlikely that the repeated postcoital use of levonorgestrel would be an acceptable routine method of contraception for most women.

Synthetic estrogens and tamoxifen as promoters of hepatocarcinogenesis

Previously, we demonstrated that the synthetic estrogens mestranol and ethinyl estradiol (EE) were strong promoters of hepatocarcinogenesis initiated in intact female rats by prior treatment with diethylnitrosamine (J. D. Yager, H. A. Campbell, D. S. Longnecker, B. D. Roebuck, and M. C. Benoit, Cancer Res. 1984; 44:3862-3869). In subsequent studies designed to elucidate possible mechanisms of promotion by EE, we investigated whether the antiestrogen tamoxifen was antagonistic to the effects of EE (J. D. Yager, B. D. Roebuck, T. L. Paluszcyk, and V. A. Memoli, Carcinogenesis 1986; 7:2007-2014). In these and more recent studies we found that tamoxifen inhibited the stimulatory effects of EE on pituitary size, liver DNA synthesis, and, in cultured hepatocytes, the potentiation by EE of epidermal growth factor-induced DNA synthesis. Furthermore, tamoxifen also inhibited the ability of EE to promote hepatocarcinogenesis. However, paradoxically, tamoxifen alone enhanced the appearance of gamma-glutamyl transpeptidase positive foci in diethylnitrosamine-initiated livers indicating that it is a promoter of hepatocarcinogenesis.

Schistosoma mansoni and S. japonicum: comparison of levels of ultraviolet irradiation for vaccination of mice with cercariae

When cercariae of Schistosoma mansoni and of S. japonicum were irradiated with various levels of u.v. light at 254 nm, their development to perfusable worms was reduced to below 1% at about 200 microW min cm-2. Cercariae attenuated with about 300 microW min cm-2 induced partial resistance against an homologous challenge infection in mice. No differences were observed between the two schistosome species when the same treatment was given to the cercariae. Thus the same u.v. dose can confer immunizing ability to cercariae of both S. mansoni and S. japonicum.

Regulation of rat hepatocyte epidermal growth factor receptor by the liver tumor promoter ethinyl estradiol

We have previously demonstrated that the liver tumor promoter ethinyl estradiol (EE) greatly enhanced the DNA synthetic response of rat hepatocytes in primary culture to epidermal growth factor (EGF). This effect was associated with a 2-fold increase in surface EGF receptor number. In this report, we demonstrate that the increase in cell surface [125I]EGF binding caused by EE is time dependent, beginning at 8 h and reaching a plateau at 18 h. This increased EGF binding was accompanied by a comparable increase in the amount of total EGF receptor protein. In vivo, EE treatment also increased the number of EGF binding sites. EE treatment did not increase the rate of [35S]methionine incorporation into immunoprecipitated EGF receptor protein, nor did it appear to affect the steady-state levels of EGF receptor mRNA compared to that found in controls. However, EE treatment did cause an increase in the half-life of EGF receptor protein from 4.5 +/- 0.5 h in control hepatocytes to 10.4 +/- 1.8 h. Taken together, these results indicate that the EE-induced 2-fold increase in EGF receptor levels, which is associated with the potentiation of responsiveness to EGF, was brought about by stabilization of receptor protein.

Schistosoma japonicum: an ultraviolet-attenuated cercarial vaccine applicable in the field for water buffaloes

Water buffaloes were vaccinated three times with 10,000 Schistosoma japonicum cercariae irradiated with ultraviolet (uv) light at a dose of 400 microW x min/cm2. The irradiation was performed with cheap, simple, and portable equipment in a rural area of Hubei Province (People's Republic of China). A challenge infection of 1000 untreated cercariae was given to six vaccinated and six naive control buffaloes, while two vaccinated animals were not challenged. The experiment was terminated 6 weeks after the challenge. Control animals had lost body weight and harbored a mean of 110 worms and 37 eggs per gram of liver. The vaccinated animals gained weight after the challenge and developed 89% resistance to infection with S. japonicum. Since schistosomiasis japonica is nowadays transmitted in China predominantly by domestic livestock, a uv-attenuated cercarial vaccine for bovines may contribute to the control of this disease.

Comparative cross-over pharmacokinetic study on two types of postcoital contraceptive tablets containing levonorgestrel

A pharmaceutical and pharmacokinetic study was carried out on levonorgestrel tablets from two different sources (Hungarian- and Chinese-made). Both preparations contained 0.75 mg levonorgestrel and had been shown to have similar contraceptive efficacy and side effects when used for postcoital contraception. Absorption and bioavailability of the Hungarian-made tablets were greater as evidenced by higher serum concentrations of levonorgestrel, a greater area under the concentration-time curve during the first 24 hours, and a more marked suppressive effect on SHBG levels. These differences most probably reflect differences in their pharmaceutical formulation, in particular the extent of tablet dissolution and the degree of micronisation of levonorgestrel.

Metabolism of the liver tumor promoter ethinyl estradiol by primary cultures of rat hepatocytes

Previously, we reported that relatively high micromolar concentrations of the liver tumor promoter 17 alpha-ethinyl estradiol (EE2) stimulated DNA synthesis and enhanced the DNA synthetic response to epidermal growth factor (EGF) in primary cultures of female rat hepatocytes [J.D. Yager, B.D Roebuck, T.L. Paluszcyk, and V.A. Memoli, Carcinogenesis 7, 2007-2014 (1986); Y.E. Shi and J.D. Yager, Cancer Res. 49, 3574-3580 (1989)]. In this study, our goal was to examine the metabolism of EE2 in cultured hepatocytes. After 4, 24, and 48 hr of culture, hepatocytes maintained their ability to convert up to 95% of a 4 nM concentration of [3H]EE2 to polar conjugates within 4 hr. EE2 at 2 microM was also 95% metabolized within 4 hr. HPLC analysis of the metabolites confirmed the rapid disappearance of [3H]EE2 and the formation of polar conjugates as detected by organic extraction. HPLC separation of hydrolyzed conjugates indicated that the major aglycone was the parent compound, EE2. In general, the metabolites differed both qualitatively and quantitatively from those reported in vivo in the rat. The rapid metabolism of EE2 by hepatocytes in culture may, at least in part, explain the high concentrations of EE2 required to stimulate DNA synthesis in cultured hepatocytes and to potentiate the response to EGF.

Pharmacokinetic study of orally administered RU 486 in non-pregnant women

A method based on HPLC was devised for the estimation of RU 486 in blood and utilised to study the pharmacokinetics of a single dose of 50 mg RU 486 administered orally to 12 women on day 7 of the cycle. The dose was rapidly absorbed with peak plasma concentration between 1 and 2 hours. Distribution was also rapid (mean t1/2 alpha: 1.4h), whereas elimination was slow (mean t1/2 beta: 28.3 h). RU 486 was still detectable in some women at 72 h after administration. The plasma concentrations fitted the equation for a two-compartment open model from which the pharmacokinetic parameters were calculated. The mean total plasma clearance was 3.0 l/h, and the comparison of our data with those published studies suggests that the pharmacokinetics of RU 486 in Chinese women are similar to those of other populations.

Termination of early human pregnancy with RU 486 (mifepristone) and the prostaglandin analogue sulprostone: a multi-centre, randomized comparison between two treatment regimens

A multi-centre, randomized trial was conducted to compare the efficacy and side-effects of two combination regimens of the antiprogestin RU 486 and the intramuscular PGE2 analogue sulprostone for termination of early pregnancy (amenorrhoea up to 49 days). Women in the 3-day group (n = 125) received 25 mg RU 486 twice daily for 3 days plus a single injection of 0.25 mg sulprostone in the morning of the third day of antiprogestin treatment. In the 4-day group (n = 126), RU 486 was given for 4 days and the sulprostone injection in the morning of the fourth day. Treatment outcome in the two groups was similar. Overall, 88.8% had a complete abortion, 6.8% an incomplete abortion and 2.4% were treatment failures; in the remaining 2% treatment outcome could not be determined. Only three of the six women with treatment failure still had detectable fetal heart activity when the pregnancy was terminated by vacuum aspiration two weeks after the start of treatment. Five of the 17 interventions for incomplete abortion were carried out as emergency procedures because of heavy bleeding; two of these five women were given a blood transfusion. The majority of the curettages (10/17) were performed in one centre. If the data from this centre and the women with undetermined treatment outcome were excluded, the rates for complete abortion, incomplete abortion and treatment failure in the remaining six centres were 93.6, 3.7 and 2.7%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of the liver tumor promoter ethinyl estradiol on epidermal growth factor-induced DNA synthesis and epidermal growth factor receptor levels in cultured rat hepatocytes

The objective of this study was to determine whether DNA synthesis induced in the livers of female rats treated with ethinyl estradiol (EE) was due to direct effects of this synthetic estrogen on hepatocytes. Hepatocytes, obtained by collagenase perfusion from female Lewis rats, were cultured in serum-free medium containing low or no phenol red and supplemented with insulin, transferrin, and selenium. When present at 10-15 microM for the initial 30 h of culture, EE caused a subsequent 2-2.7-fold increase in hepatocyte DNA synthesis. Pretreatment of the hepatocytes with EE during the first 30 h of culture caused an EE concentration-dependent enhancement of their subsequent DNA synthetic response to epidermal growth factor (EGF). Pretreatment with EE shifted the EGF dose-response curve, causing a dramatic enhancement of the response to EGF beginning at 2 ng EGF/ml. The response to a saturating (25 ng/ml) dose of EGF was also greatly enhanced. Determination of the effect of EE on hepatocyte surface EGF receptors revealed that the increased responsiveness of DNA synthesis to EGF was accompanied by a twofold increase in EGF receptor number per cell. These results indicate that EE has direct, growth-related effects on hepatocytes which may contribute to liver growth induced in vivo by this tumor promoter.

Enhancement in rats by the liver tumor promoter ethinyl estradiol of a serum factor(s) which is stimulatory for hepatocyte DNA synthesis

Fractionation of female rat serum or plasma on Sephadex G-200 revealed the presence of an activity stimulatory for hepatocyte DNA synthesis. Treatment of female rats with the liver tumor promoter ethinyl estradiol (EE) at 2.5 micrograms/day caused a 1.6 fold increase in the level of this activity at 24 hr in both serum and plasma. The stimulatory activity had a molecular weight of 135 kD, was sensitive to trypsin and heating and was not inhibited by the antiestrogen tamoxifen or antibody to epidermal growth factor (EGF). However, the pooled active fractions from EE-treated rats competed to a greater extent than comparable fractions from control rats for specific [125I]-EGF binding to rat liver membranes. These results demonstrate that treatment of female rats with EE, under conditions known to stimulate liver growth, caused an increase in level of a factor(s) stimulatory for hepatocyte DNA synthesis and whose activity may be mediated through the EGF receptor.

The effect of levonorgestrel administered in large doses at different stages of the cycle on ovarian function and endometrial morphology

In a pharmacokinetic study, levonorgestrel (L-NOG) 0.75 mg was administered orally to 10 swedish women in the early follicular phase of the menstrual cycle. L-NOG levels were measured after L-NOG administration. A peak level of 16 nmol/l was reached after 2 hours, T 1/2 was estimated to be 14.5 hours (8.5-18.5) in the 24-48-hour interval after dosing. Seventy-two women (in Stockholm, Bombay and Shanghai) were assigned to 4 treatment groups and studied during a control cycle, a treatment cycle and a posttreatment cycle when 0.75 mg L-NOG was administered orally for 4 days in the follicular phase, periovulatory period or luteal phase. Peripheral blood was drawn 3 times weekly during the entire study for the assay of estradiol and progesterone. In 22 women in Stockholm, an endometrial biopsy was obtained on cycle day 20-22 in all 3 cycles studied. When L-NOG was administered on periovulatory days 9, 11, 13, and 15, 3 women showed follicular activity only, 7 exhibited follicular activity followed by insufficient luteal function and 7 women ovulated normally. When L-NOG was administered on periovulatory days 11, 12, 16 and 19, 7 women ovulated during treatment, 6 women exhibited follicular activity followed by insufficient luteal function and 5 exhibited follicular activity only. When L-NOG was administered in the follicular or luteal phase, no effect on ovarian function was seen. No significant prolongation of the cycle lengths was seen when L-NOG was taken during the follicular phase. Only minor effects in the endometrium were observed during treatment.