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C-myc and tumor suppressor gene product expression in developing and term human trophoblast
96
Citations from the literature /International
Journal of Gynecology & Obstetrics 49 (1995) 87-97
in isolated human endometrial glands and stromal cells in culture. Stromal cells and glands were obtained from endometrial tissue by collagenase dispersion followed by sieve filtration. They were plated into 24-well multiwell plates in Ham’s FIO medium supplemented with 5% fetal calf serum and used at 70-80% confluence. Scatchard analysis revealed a single class of high-affinity binding sites in both cell types with apparent dissociation constants of 1.17 0.6 (n = 15) and 1.200.3 (n = 8) nmol I-I for stromal cells and glands, respectively. The concentration of receptors was higher in stromal cells than in glands, 719 377(n = 16)and 310 177(n = 8) fmol mg-1 protein, respectively. Epidennal growth factor labelled with “sI was displaced from the receptor by EGF and transforming growth factor, but not insulin, insulin-like growth factor, fibroblast growth factor, or platelet-derived growth factor. Binding was shown to be dependent on time and temperature. Downregulation of the receptor was demonstrated by preincubating cells with 5 nmol EGF l-l, which reduced receptor concentrations by 75%. 12-OTetradecanoylphorbol-13-acetate decreasedthe affinity of the receptor for EGF changing the dissociation constant from I .8 to 3.9 nmol I- I. A suitable system for investigating the regulation of this receptor in human endometrium was established.
Improved detection of fetal ceils from maternal blood with polymerase chain reaction
characteristics and endothelium-dependent and endotheliumindependent relaxation were examined. STUDY DESIGN: By meansof a small vesselmyograph arteries of mean normalized internal diameter 353.22 * 13.14 pm were studied under isometric conditions. Contractile function was assessedwith a variety of agonists, including angiotensin II, endothelin-I. the thromboxane mimetic U46619, prostaglandin E,, and prostaglandin F (2o). The effect of physiologic and supraphysiologic PO2 on vascular function was also examined. Relaxation was assessedin response to known endotheliumdependent vasodilators, including acetylcholine, bradykinin, histamine, and A23187 and to sodium nitroprusside (endothelium independent). The effect of indomethacin and the nitric oxide synthase inhibitor, N(G)-nitro-L-arginine methyl ester on contractile function was also evaluated. RESULTS: Sensitivity to sodium nitroprusside was reduced by a high POz. U46619 was the most potent constrictor agonist studied. The response of precontracted arteries to known endotheliumdependent vasodilators was minimal, other than for histamine, which led to modest relaxation. The constrictor response to U46619was increasedin the presenceof N(G)-nitro-L-arginine methyl ester. CONCLUSIONS: Oxygen tension may be an important determinant of relaxation in small placental arteries. Receptor-mediated release of endothelium-derived relaxing factor is not a major mechanism in the fetoplacental circulation.
Adkison L.R.; Andrews R.H.; Vowel] N.L.; Koontz W.L. USA
AM J OBSTET GYNECOL 1994 170/3(952-955) OBJECTIVE: The objective was to test the reliability of new deoxyribonucleic acid primers that have previously been used very efficiently by this laboratory with amniolysate samples to amplify a 248 bp Y-specific, repeated sequencefrom maternal blood during pregnancy. STUDY DESIGN: Blood samples were obtained from 50 women during weeks I I and I6 of pregnancy and were analyzed for the presence of the Y chromosome-specificsequences.RESULTS: Y-specific fragments were identified in I9 of 24 (79.2%) women after one complete amplification. A second amplification of these samples negative for Y-specific fragments revealed three additional samplespositive for the Y chromosome-specific fragment. Only two male fetusesremained unidentified. Overall, 91.7% male fetusesand 96% of all fetuses(48/50) in these women were correctly identified. CONCLUSIONS: The primers described in this study provide an additional or alternative tool for the determination, by meansof the polymerase chain reaction, of Y chromosomebearing cells in maternal circulation.
Fuoctioaal characteristics of small placental arteries
McCarthy A.L.; Woolfson R.G.; Evans B.J.; Davies D.R.; Raju SK.; Poston L. GBR
AM J OBSTET GYNECOL 1994 170/3(945-951) OBJECTIVES: The aim of this study was to investigate characteristics of placental arteries capable of influencing vasomotor tone in the fetoplacental vascular bed. Contractile
C-myc ami tomor suppressor gene product expression in develop ing aml term human trophoblast
Roncalli M.; Bulfamante G.; Viale G.; Springall D.R.;Alfano R.; Comi A.; Maggioni M.; Polak J.M.; Coggi G. ITA
PLACENTA 1994 I5/4 (399-409) Proliferation and differentiation of villous trophoblast during placental development, from an early stage to full-term, were investigated in routinely fixed and processedtissues, by meansof the immunocytochemical localization of the cell cyclerelated proto-oncogene c-myc and the ~53 and retinoblastoma susceptibility (Rb) tumor-suppressorgene products. The proliferative activity of the trophoblast was determined using an antibody against proliferating cell nuclear antigen (PCNA) which stains all proliferating cells in paraffin-embedded tissues. Diffuse nuclear immunoreactivity for PCNA, c-myc and Rb geneproducts was a consistent finding in early cytotrophoblast: c-myc product expression was also detectable in both layers of mid-gestation trophoblast. Only scattered cytotrophoblastic nuclei of early gestational placenta displayed immunostaining for ~53 gene product. In full-term placenta c-myc expression was undetectable while Rb gene product and PCNA immunoreactivity declined markedly. These results indicate that the expressionof the above genesis spatio-temporally regulated during placental development. A potential involvement of the oncosuppressorgeneproducts ~53 and Rb in the control of trophoblastic proliferation and of c-myc in the control of both the proliferative and differentiation pathways of trophoblastic cells is suggested.
Citations from the literature /International
Journal of Gynecology & Obstetrics 49 (1995) 87-97
in isolated human endometrial glands and stromal cells in culture. Stromal cells and glands were obtained from endometrial tissue by collagenase dispersion followed by sieve filtration. They were plated into 24-well multiwell plates in Ham’s FIO medium supplemented with 5% fetal calf serum and used at 70-80% confluence. Scatchard analysis revealed a single class of high-affinity binding sites in both cell types with apparent dissociation constants of 1.17 0.6 (n = 15) and 1.200.3 (n = 8) nmol I-I for stromal cells and glands, respectively. The concentration of receptors was higher in stromal cells than in glands, 719 377(n = 16)and 310 177(n = 8) fmol mg-1 protein, respectively. Epidennal growth factor labelled with “sI was displaced from the receptor by EGF and transforming growth factor, but not insulin, insulin-like growth factor, fibroblast growth factor, or platelet-derived growth factor. Binding was shown to be dependent on time and temperature. Downregulation of the receptor was demonstrated by preincubating cells with 5 nmol EGF l-l, which reduced receptor concentrations by 75%. 12-OTetradecanoylphorbol-13-acetate decreasedthe affinity of the receptor for EGF changing the dissociation constant from I .8 to 3.9 nmol I- I. A suitable system for investigating the regulation of this receptor in human endometrium was established.
Improved detection of fetal ceils from maternal blood with polymerase chain reaction
characteristics and endothelium-dependent and endotheliumindependent relaxation were examined. STUDY DESIGN: By meansof a small vesselmyograph arteries of mean normalized internal diameter 353.22 * 13.14 pm were studied under isometric conditions. Contractile function was assessedwith a variety of agonists, including angiotensin II, endothelin-I. the thromboxane mimetic U46619, prostaglandin E,, and prostaglandin F (2o). The effect of physiologic and supraphysiologic PO2 on vascular function was also examined. Relaxation was assessedin response to known endotheliumdependent vasodilators, including acetylcholine, bradykinin, histamine, and A23187 and to sodium nitroprusside (endothelium independent). The effect of indomethacin and the nitric oxide synthase inhibitor, N(G)-nitro-L-arginine methyl ester on contractile function was also evaluated. RESULTS: Sensitivity to sodium nitroprusside was reduced by a high POz. U46619 was the most potent constrictor agonist studied. The response of precontracted arteries to known endotheliumdependent vasodilators was minimal, other than for histamine, which led to modest relaxation. The constrictor response to U46619was increasedin the presenceof N(G)-nitro-L-arginine methyl ester. CONCLUSIONS: Oxygen tension may be an important determinant of relaxation in small placental arteries. Receptor-mediated release of endothelium-derived relaxing factor is not a major mechanism in the fetoplacental circulation.
Adkison L.R.; Andrews R.H.; Vowel] N.L.; Koontz W.L. USA
AM J OBSTET GYNECOL 1994 170/3(952-955) OBJECTIVE: The objective was to test the reliability of new deoxyribonucleic acid primers that have previously been used very efficiently by this laboratory with amniolysate samples to amplify a 248 bp Y-specific, repeated sequencefrom maternal blood during pregnancy. STUDY DESIGN: Blood samples were obtained from 50 women during weeks I I and I6 of pregnancy and were analyzed for the presence of the Y chromosome-specificsequences.RESULTS: Y-specific fragments were identified in I9 of 24 (79.2%) women after one complete amplification. A second amplification of these samples negative for Y-specific fragments revealed three additional samplespositive for the Y chromosome-specific fragment. Only two male fetusesremained unidentified. Overall, 91.7% male fetusesand 96% of all fetuses(48/50) in these women were correctly identified. CONCLUSIONS: The primers described in this study provide an additional or alternative tool for the determination, by meansof the polymerase chain reaction, of Y chromosomebearing cells in maternal circulation.
Fuoctioaal characteristics of small placental arteries
McCarthy A.L.; Woolfson R.G.; Evans B.J.; Davies D.R.; Raju SK.; Poston L. GBR
AM J OBSTET GYNECOL 1994 170/3(945-951) OBJECTIVES: The aim of this study was to investigate characteristics of placental arteries capable of influencing vasomotor tone in the fetoplacental vascular bed. Contractile
C-myc ami tomor suppressor gene product expression in develop ing aml term human trophoblast
Roncalli M.; Bulfamante G.; Viale G.; Springall D.R.;Alfano R.; Comi A.; Maggioni M.; Polak J.M.; Coggi G. ITA
PLACENTA 1994 I5/4 (399-409) Proliferation and differentiation of villous trophoblast during placental development, from an early stage to full-term, were investigated in routinely fixed and processedtissues, by meansof the immunocytochemical localization of the cell cyclerelated proto-oncogene c-myc and the ~53 and retinoblastoma susceptibility (Rb) tumor-suppressorgene products. The proliferative activity of the trophoblast was determined using an antibody against proliferating cell nuclear antigen (PCNA) which stains all proliferating cells in paraffin-embedded tissues. Diffuse nuclear immunoreactivity for PCNA, c-myc and Rb geneproducts was a consistent finding in early cytotrophoblast: c-myc product expression was also detectable in both layers of mid-gestation trophoblast. Only scattered cytotrophoblastic nuclei of early gestational placenta displayed immunostaining for ~53 gene product. In full-term placenta c-myc expression was undetectable while Rb gene product and PCNA immunoreactivity declined markedly. These results indicate that the expressionof the above genesis spatio-temporally regulated during placental development. A potential involvement of the oncosuppressorgeneproducts ~53 and Rb in the control of trophoblastic proliferation and of c-myc in the control of both the proliferative and differentiation pathways of trophoblastic cells is suggested.