Biosynthesis of MUC1 mucin in human endometrial adenocarcinoma is modulated by estradiol and tamoxifen.

Polymorphic epithelial mucin MUC1 is expressed by most epithelial cancers, although free natural MUC1 antibodies are present in the circulation of healthy subjects as well as in that of cancer patients. The role of MUC1 mucin molecules in cancer cells of endometrium is not precisely known. The results reported here demonstrate that MUC1 biosynthesis in human endometrial adenocarcinoma cells (Ishikawa line) is stimulated by estradiol hormone and inhibited by tamoxifen, which was measured by [(14)C]threonine or [(3)H]glucosamine incorporation into MUC1 protein. Tamoxifen applied in combination with estradiol also inhibited this process, but pre-incubation of cells with estradiol resulted in a decrease in the inhibitory effect of tamoxifen. Electroblotting and reactions with antibodies against MUC1 core protein epitopes confirmed the presence of MUC1 in cell lysates and culture media of Ishikawa cells. Reactions with lectins showed the presence of oligosaccharide structures demonstrating antigen-T activity and the presence of sialic acid residues. The results confirm that there is downregulation of MUC1 expression in cancer culture cells treated with selective estrogen receptor modulators, which may be essential for reducing the migration of cancer cells and the metastatic properties of tumor cells.

13-cis retinoic acid and all-trans retinoic acid in the regulation of the proliferation and survival of human breast cancer cell line MCF-7.

Retinoids are a group of compounds which inhibit cell proliferation and induce cellular differentiation. The aim of this study was to compare the antiproliferative activity of various concentrations of 13-cis retinoic acid (isotretinoin) and all-trans retinoic acid (tretinoin) in a culture of the estrogen-sensitive human breast cancer cell line MCF-7. Evaluation was based on [3H]thymidine incorporation into the cancer cells and through immunocytochemical analysis of cell cycle-associated PCNA and Ki-67 protein expression. Both retinoids inhibited [3H]thymidine incorporation into the cancer cells most effectively at a concentration of 3x10(-3) M. Two basic substances used for line MCF-7 culture experiments, one stimulating - estradiol - and the other inhibiting - tamoxifen - were applied. Estradiol added to a culture containing decreasing concentrations of isotretinoin (from 3x10(-3) to 3x10(-8) M) caused a statistically significant reduction in the percentage of [3H]thymidine incorporation into the cancer cell line MCF-7, compared to the 17 beta estradiol group (189.25%+/-62.64, control=100%, p<0.05). In the group of decreasing tretinoin concentrations, statistically significant differences were found only at 3x10(-3), 3x10(-4) and 3x10(-8) M. Following culture supplementation with tamoxifen (1 microM), statistically significant differences were observed only at the highest concentrations of both retinoids (3x10(-3) and 3x10(-4) M). The evaluation of breast carcinoma cells with a positive immunocytochemical reaction to PCNA and Ki-67 has revealed that isotretinoin reduces their percentage in the most determined and statistically significant way (38.00%+/-2.58 and 39.25%+/-3.09), compared to the control group (86.50%+/-9.20 and 100%+/-3.87, p<0.001 and p<0.0001) and to the estradiol group (87.00%+/-6.79 and 86.10%+/-7.0, p<0.001). Apart from their blocking effect on the cell cycle, retinoids also induce the apoptotic pathway.

[Prenatal and neonatal diagnosis of osteogenesis imperfecta in obstetrical practice]. / Diagnostyka przed i pourodzeniowa wrodzonej lamliwosci kosci (Osteogenesis imperfecta) w praktyce polozniczej.

Osteogenesis imperfecta (OI types I, II, III, IV) is a heterogeneous group of genetically disorders of connective tissue. Quantitative or qualitative abnormalities of type I collagen form pathogenetical basis of the disease. They are caused by mutations in genes encoding collagen proteins or enzymes involved in collagen biosynthesis. The clinical features of each type usually correspond to the type of mutation. Typical manifestations are fragile bones with multiple bone fractures and bone deformities. Currently applied diagnosis in utero of OI II and sometimes OI III may be performed. Diagnosis of other OI phenotypes cannot be made until after birth. We present three cases of OI II (four children) diagnosed, in utero, by ultrasound examination. The analysis in work include: 1. the prenatal sonographic features of OI type II 2. the biochemical properties of collagen in the above cases 3. genetic counselling of the families affected by OI.

[The role of nitric oxide in carcinogenesis and progression of neoplastic processes]. / Rola tlenku azotu w karcinogenezie i progresji procesu nowotworowego.

The aim of the review is to outline the current knowledge about the role of nitric oxide in the processes of proliferation and apoptosis in tumor. Special emphasis has been placed on its direct cytotoxic influence on a cell where as a highly active free radical it may compromise different cellular functions. Nitric oxide literature, regarding its role in the pathogenesis of some gynecological and breast cancer has been briefly reviewed.

Defects of type I procollagen metabolism correlated with decrease of prolidase activity in a case of lethal osteogenesis imperfecta.

We have studied the structure and metabolism of type I procollagen in a case of perinatal lethal osteogenesis imperfecta (OI) type II. Cultured skin fibroblasts from the proband synthesized both normal and abnormal forms of type I procollagen. Some abnormal, overmodified molecules were secreted by OI cells, although less efficiently than normal molecules from control cells. The OI fibroblasts accumulated large amounts of abnormal proalpha1(I) and proalpha2(I) chains intracellularly. The extracellular collagenolytic activity was decreased compared to control cells. Furthermore, OI cells produced less type I procollagen and demonstrated lower capacity to synthesize DNA than control cells. We have found that in contrast to prolinase activity, the activity of prolidase (an enzyme essential for collagen synthesis and cell growth) is also significantly reduced in OI cells. No differences were found in the amount of the enzyme protein recovered from both the OI and control cells. However, we found that expressions of beta1 integrin and insulin-like growth factor-I receptor (receptors known to play an important role in up regulation of prolidase activity) were decreased in OI cells compared to control cells. The decrease in prolidase activity may provide an important mechanism of altered cell growth and collagen metabolism involved in producing the perinatal lethal form of the OI phenotype.

The influence of glyco-nitric oxide conjugate on proliferation of breast cancer cells in vitro.

The aim of the study was to evaluate the influence of a nitric oxide donor: Glyco-2-SNAP on the proliferation status of two breast cancer cell lines: MDA-MB-231 and MCF-7. The study was performed by the thymidine incorporation method as well as by the immunocytochemical detection of the Ki-67 antigen. We found that the donor significantly inhibits the process of proliferation. The effect of the Glyco-2-SNAP is significant in both lines, however stronger in MDA -MB-231 cells where the donor at 100 microM inhibited DNA synthesis from 70462.000 dpi (SD +/-2066.175, n=4) for control to about 3120.250 dpi (SD +/-971.689 n=4). In UCF-7 cells the control gave 31142.500 dpi (SD +/-712.9214, n=4) and the treatment with 100 microM of Glyco-2 SNAP resulted in 4095.50 dpi. (SD +/-315.723, n=4). In both lines SNAP, classical NO donor also had an inhibitory effect but much higher concentrations. Ki-67 protein expression was significantly influenced by Glyco-2-SNAP at 100 microM (42.5% +/-6.45) concentrations in MDA-MB 231. No effect of G-SNAP was seen in MCF-7 cells. The control staining for both lines was about 90%. Our results presesent the possibility of exploiting a novel kind of NO donor as a potential mode of treatment that may be an alternative to classical therapeutic strategies in breast cancer.

Identification of a pepsin-sensitive type III-like collagen in breast cancer MCF-7 cells.

Electrophoretic analysis of [3H]proline-labeled culture medium proteins of MCF-7 cells revealed the presence of disulfide-bonded, bacterial collagenase-sensitive component which comigrated with pro(alpha)1 chains of type III and type I collagens. However, it was pepsin- and trypsin-sensitive. Within 1 min of pepsin-digestion, a component with a size of alpha1 chain of type I or III collagen was produced which degraded after 5 min of digestion. Similarly, the pepsin-sensitive band was completely degraded by trypsin at 30 degrees C within 5 min. We examined CNBr peptides of the collagenous band and demonstrated that it was alpha1 chain of type III collagen. When MCF-7 cells were cultured in the presence of 2 nM estradiol, a marked increase in the level of collagen secreted into medium was found. The identified proteinase-sensitive type III-like collagen as major protein of extracellular matrix, would be expected to be more susceptible to degradation which might contribute to tumor progression.

[Biochemical mechanism of raloxifen and tamoxifen action for the prevention of breast cancer. Studies in vitro]. / Mechanizmy biochemiczne dzialania tamoxifenu i raloxifenu w prewencji raka sutka. Badania in vitro.

Cancer growth follows fine balance disturbance between cell proliferation, differentiation and death. It has been shown that mutation of 4 to 5 genes controlling cellular proliferation events may be contributive to carcinogenesis. Estrogens play a central role in reproductive physiology. They are also a causative factors in the pathogenesis of neoplastic and non-neoplastic diseases, including breast cancer. The estrogen dependency of human breast cancer has been successfully exploited in the treatment of early and advanced diseases and provides a unique opportunity for chemoprevention of this common malignancy. The aim of present study was to examine the effects of tamoxifen and raloxifen on the induction of apoptosis and proliferative activity of human breast adenocarcinoma MCF-7 cells. It has been found that both tamoxifen and raloxifen decreased the speed of cell cycle in MCF-7 cells and acts as proapoptotic factors. It reduces viability of cancer cells and probability of neoplastic clone multiplification. This effect conducts to limitation of cancer expansion.

Influence of estrogen, antiestrogen and UV-light on the balance between proliferation and apoptosis in MCF-7 breast adenocarcinoma cells culture.

Studies of the mechanism of actions of estrogen, antiestrogen and physical factors may provide clues to an understanding of breast cancer growth and/or regression regulation and thus identify novel targets for therapeutic intervention. Defective control of apoptosis appears to play a central role in the pathogenesis of neoplasia. Conversely, cancer therapy and ionizing radiation can induce cancer cell death by apoptosis and/or necrosis. bcl-2 gene and p-53 gene products have been both linked to programmed cell death pathways. We have analyzed the effect of estradiol, tamoxifen and UV exposure on the induction of apoptosis, expression of p53 and bcl-2 gene products as well as the proliferative activity (expressed as [3H]thymidine incorporation and PCNA and MPM2 antigens involvement) in MCF7. It has been found that estradiol increases the speed of cell cycle in MCF7 and acts as antiapoptotic factor. Tamoxifen has multiple influence on the rate of growth of cancer cells: depends on estrogen receptor (ER), conducts reduction of proliferation rate; depends on ER and other mechanisms conducts to suppressions of Bcl-2 protein expression and induction of cell death through apoptotic pathway. Estradiol prevents the apoptotic influence of tamoxifen probably by enhancement of Bcl-2 protein expression and does not prevent the inhibition of proliferation rate. The irradiation with UV induces apoptosis by over-expression of p53 and down-regulation of bcl-2 gene.

Estrogen-dependent regulation of prolidase activity in breast cancer MCF-7 cells.

Prolidase [EC 3.4.13.9] plays an important role in the recycling of proline for collagen synthesis and cell growth. The increase in the enzyme activity is correlated with the increased intensity of collagen turnover, thus reflecting the intensity of collagen metabolism. Since estrogens alter collagen metabolism, it can be assumed that the changes may be reflected by prolidase activity. The effects of estrogen and antiestrogen (tamoxifen on the prolidase and collagenase activities and collagen biosynthesis) were measured in the estrogen-receptor (ER)-positive breast cancer cell line. Estradiol stimulated collagen biosynthesis and extracellular prolidase and collagenase activities in cultured MCF-7 cells without an effect on collagen accumulation in the extracellular matrix produced by these cells. On the other hand, tamoxifen inhibited the estrogen-dependent stimulatory effect on collagen biosynthesis but did not inhibit the stimulatory effect of estrogen on prolidase and collagenase activities. The inhibitory effect of tamoxifen on estrogen-dependent stimulation of collagen synthesis in MCF-7 cells and lack of its effect on estrogen-dependent stimulation of prolidase and collagenase activities suggest that both processes (collagen synthesis and degradation) are independently regulated in MCF-7 cells, possibly through antagonist, agonist and other estrogen receptor-independent actions of tamoxifen. Increased extracellular prolidase activity in estrogen-stimulated MCF-7 cells indicates potential diagnostic value of tissue prolidase in determining the ER status of breast cancer.

[Pregnancy and delivery after the transfer of one blastocyst with enzymatically removed zona pellucida]. / Ciaza i poród po transferze blastocysty pozbawionej enzymatycznie oslonki przejrzystej.

OBJECTIVES: The embryonic development up to the blastocyst stage and hatching from zona pellucida are prerequisites for implantation and successful pregnancy. It is suggested that one of the possibilities limiting the implantation rate is impaired hatching. To overcome this problem an artificial alteration of the zona pellucida have been carried out in many laboratories. DESIGN: The report of the first pregnancy in Poland obtained after the transfer of enzymatically zona removed blastocyst. MATERIALS AND RESULTS: The patient was previously treated three times in in vitro fertilisation program without success. In the fourth program the embryos were cultured in co-culture of Vero cells to the blastocyst stadium. On the day 5 after insemination the zona of cavitating and expanding blastocyst was removed by pronase. The zona free blastocyst was transferred to the uterus. As a result of implanted blastocyst the ongoing pregnancy developed normally and the patient delivered healthy baby. CONCLUSION: Enzymatic zona pellucida hatching probably increases the rate of implantation. It is simple, safe and economic techniques.