Rosalie Ber

Growth hormone (GH) receptors in prostate cancer: gene expression in human tissues and cell lines and characterization, GH signaling and androgen receptor regulation in LNCaP cells

Various hormones and growth factors have been implicated in progression of prostate cancer, but their role and the underlying molecular mechanism(s) involved remain poorly understood. In this study, we investigated the role of human growth hormone (GH) and its receptor (GHR) in human prostate cancer. We first demonstrated mRNA expression of GHR and of its exon 9-truncated isoform (GHR(tr)) in benign prostate hyperplasia (BPH) and prostate adenocarcinoma patient tissues, as well as in LNCaP, PC3 and DU145 human prostate cancer cell lines. GHR mRNA levels were 80% higher and GHR(tr) only 25% higher, in the carcinoma tissues than in BPH. Both isoforms were also expressed in LNCaP and PC3 cell lines and somewhat less so in DU145 cells. The LNCaP cell GHR protein was further characterized, on the basis of its M(r) of 120kDa, its binding to two different GHR monoclonal antibodies, its high affinity and purely somatogenic binding to (125)I-hGH and its ability to secrete GH binding protein, all characteristic of a functional GHR. Furthermore, GH induced rapid, time- and dose-dependent signaling events in LNCaP cells, including phosphorylation of JAK2 tyrosine kinase, of GHR itself and of STAT5A (JAK2-STAT5A pathway), of p42/p44 MAPK and of Akt/PKB. No effect of GH (72h) could be shown on basal or androgen-induced LNCaP cell proliferation nor on PSA secretion. Interestingly, however, GH caused a rapid (2-12h) though transient striking increase in immunoreactive androgen receptor (AR) levels (< or =5-fold), followed by a slower (24-48h) reduction (< or = 80%), with only modest parallel changes in serine-phosphorylated AR. In conclusion, the GH-induced activation of signaling pathways, its effects on AR protein in LNCaP cells and the isoform-specific regulation of GHR in prostate cancer patient tissues, suggest that GH, most likely in concert with other hormones and growth factors, may play an important role in progression of human prostate cancer.

Ethical Issues in Gestational Surrogacy

The introduction of contraceptive technologies hasresulted in the separation of sex and procreation. Theintroduction of new reproductive technologies (mainlyIVF and embryo transfer) has led not only to theseparation of procreation and sex, but also to there-definition of the terms mother and family.For the purpose of this essay, I will distinguishbetween:1. the genetic mother – the donor of the egg;2. the gestational mother – she who bears and gives birth to the baby;3. the social mother – the woman who raises the child.This essay will deal only with the form of gestationalsurrogacy in which the genetic parents intend to bethe social parents, and the surrogate mother has nogenetic relationship to the child she bears anddelivers. I will raise questions regarding medicalethical aspects of surrogacy and the obligation(s) ofthe physician(s) to the parties involved. I will arguethat the gestational surrogate is “a womb to rent,”that there is great similarity between gestationalcommercial surrogacy and organ transplant marketing.Furthermore, despite claims to freedom of choice andfree marketing, I will claim that gestationalsurrogacy is a form of prostitution and slavery,exploitation of the poor and needy by those who arebetter off. The right to be a parent, although notconstitutional, is intuitive and deeply rooted.However, the issue remains whether this rightoverrules all other rights, and at what price to theparties involved. I will finally raise the followingprovocative question to society: In the interim periodbetween todays limited technology and tomorrowsextra-corporeal gestation technology (ectogenesis),should utilizing females in PVS (persistent vehetativestate) for gestational surrogacy be sociallyacceptable/permissible – provided they have leftpermission in writing?

Increasing empathy among medical students

Summary. The objective of the research was to evaluate the short‐ and long‐term effectiveness of teaching medical students interviewing skills. Methods of teaching communication skills included a workshop for clinical instructors, as an indirect approach, a workshop for medical students, as a direct approach, and a combination of both. Results demonstrated that in order to stimulate medical students to use supporting‐interview skills, they themselves should participate in an interpersonal skills workshop. Being taught these skills by teachers who have participated in the workshop does not have the same positive effect.

An evaluation of the short-term effects of an interpersonal skills course

A course on interpersonal skills (IPS) has been introduced as part of the clerkship in internal medicine. The course is given in small groups (8‐10 students) with two tutors attached to each group. The use of trigger films in the IPS course has been described previously ( Alroy & Ber, 1982 ). An evaluation of the short‐term (2‐month) effects of the method is now reported.

Twenty Years of Experience Using Trigger Films as a Teaching Tool

Trigger films or trigger videos that depict patient—physician encounters can be used to provoke reflection, stimulate discussion, help learners confront their feelings and give learners practice in responding to challenges. For more than 20 years at the B. Rappaport Faculty of Medicine, the authors have used trigger films to teach/demonstrate the doctor—patient relationship, medical ethics, diagnostic thinking, professional behavior, and the application of the principles of the Israeli Patient Bill of Rights, and have found them to be an excellent tool for provoking active participation in small-group discussions. The authors describe how they have effectively produced and used trigger films in an Introduction to Clinical Medicine course. They highly recommend the “homemade” production of trigger films.

Extinction of Ig genes expression in myeloma x fibroblast somatic cell hybrids is accompanied by repression of the oct-2 gene encoding a B-cell specific transcription factor.

In most instances, fusion of differentiated cell types with fibroblasts has resulted in the extinction of differentiation‐specific traits of the nonfibroblast parental cell. To explore the genetic basis of this phenomenon, we have used a series of somatic cell hybrids between myeloma cells and fibroblasts. Previous findings show that in these hybrids expression of the immunoglobulin (Ig) genes was extinguished at the transcriptional level. Our present results show that NF‐kappa B transcription factor, known to be critical for kappa‐chain enhancer activity, is present although in a lower amount, in the nucleus and in the cytosolic fraction of most of these hybrids (probably attached to the previously postulated I‐kappa B inhibitor). In contrast, the expression of the NF‐A2/OTF‐2 transcription factor encoded by the oct‐2 gene, which binds to the octameric motif located in the Ig promoters and heavy chain gene enhancer, is extinguished at the transcriptional level. Our data thus suggest that extinction of Ig genes expression occurs via an indirect mechanism in which a fibroblast factor suppresses transcription factor(s) which are critical for Ig transcription.

Extinction of expression of immunoglobulin genes in myeloma X fibroblast somatic cell hybrids.

Adherent hybrids between immunoglobulin-producing mouse myeloma cells and fibroblasts do not produce immunoglobulin polypeptide chains. These hybrids retained the actively rearranged immunoglobulin genes of the myeloma parental cells but lacked immunoglobulin heavy- and light-chain RNA transcripts. We conclude that the shutoff of immunoglobulin production in these hybrids occurs at the transcription or early processing level.

Teaching the cultural dimensions of the patient-physician relationship: a novel approach using didactic trigger films

The use of trigger films (TFs) for undergraduate teaching is well established in the Technion School of Medicine and elsewhere. These are typically based on a written script highlighting diverse issues within the patient-physician relationship (PPR). We report here on the staging of a filmed script-free encounter between a physician and an actress-patient as a further development of the TF approach. This involved the creation of a clinical interaction in which the patients revealed cultural background demanded an adaptive response from the physician in order to achieve a stable PPR and to institute effective treatment. Considerable improvisation was thus required. Prior directorial manipulation of the conditions of the interview enhanced the didactic power and goals of the TF. After completion of the filming, the physician and the actress studied the video and then repeated the interview within the same situation free of directorial input. The two sequential videotaped interviews constitute the final product. These TFs appear to carry a wide spectrum of didactic messages at many levels including the need to relate effectively to the cultural aspects in the PPR, and the importance of self-observation as a tool for change and learning.

Prolactin and Testicular Leydig Cell Function: Characterization of Prolactin Receptors in the Murine MA-10 Testicular Leydig Cell Line

Abstract The direct role of prolactin (PRL) in testicular function is still unclear, mostly because of lack of a suitable in vitro model. To establish the suitability of the MA-10 murine tumor Leydig cell line for the study of PRL receptors (PRLR) and effects on steroidogenesis, we initially characterized PRLR on cultured MA-10 cells. The specific binding (Bs) of [125l]human growth hormone (hGH) depends on time, temperature, and Mg2+ ion and protein concentrations, with absolute specificity for the lactogenic hormones hGH and ovine PRL. Bs is saturable and is to a single class of high-affinity (Ka = 3.6 × 109 M -1) low-capacity (B max = 19.5 fmol/mg protein) binding sites. The molecular weight of PRLR, determined by cross-linking to [125l]hGH, SDS-PAGE and autoradiography, is 35 kDa for the free receptor, suggesting that the short-form PRLR protein, previously described in liver and mammary glands, is that primarily found in MA-10 cells. Thus, the demonstration of specific PRL binding sites on MA-10 Leydig cells, with characteristics similar to primary Leydig cell PRLR, suggests that this cell line can serve as a good model for both the study of PRLR mechanism of action and the role of PRL in Leydig cell function.

Characterization and regulation of prolactin receptors in MA-10 Leydig cells

The aim of this study is to further characterize the prolactin receptors (PRL-R) previously reported in the murine Leydig tumor MA-10 cell line, as well as to study their homologous and heterologous regulation. Two forms of PRL-R, a high and a low molecular weight form, were revealed by studies of covalent crosslinking of 125I-human GH to cultured MA-10 cells or cell membranes and immunoprecipitation of the solubilized PRL-R complexes with polyclonal anti PRL-R antibody, followed by SDS-PAGE and autoradiography. The long form had a molecular weight of 101 kDa and was predominant when the study was performed in the presence of protease inhibitors. The short form, with a molecular weight of 39 kDa, appeared, at least in part, to be a proteolytic product of the longer form. The same size forms of PRL-R were detected by crosslinking studies in the parental C57BL/6 mouse testicular Leydig cells, indicating the physiological relevance of the MA-10 cell model to the study of Leydig cell PRL-R. Homologous down-regulation of PRL-R was demonstrated in cultured MA-10 cells exposed for 24 h to increasing concentrations of PRL. In contrast, heterologous, 3 5-fold up-regulation of PRL-R was induced by various cAMP-elevating agents, including 8-bromo-cAMP (10(-4) -10(-3) M), dibutyryl cAMP (3 x 10(-3) M) and cholera toxin (1-10 ng/ml), although not by hCG (up to 100 ng/ml). This up-regulatory effect was apparently the result of a change in affinity, since cholera toxin caused a 2.4-fold increase in PRL-R affinity, with no change in the number of binding sites. In summary, these studies provide further evidence that MA-10 Leydig cells can serve as a physiologically relevant model for the study of PRL and PRL-R interactions, both at the functional level, as shown in our previous study, and at the structural and regulatory levels as shown in the current study.