[TMPRSS2-Erg/AR-V7: Prognostic value of tests in urine and biopsy rince material in prostate cancer]. / TMPRSS2-Erg/AR-V7 : valeur diagnostique des tests urinaires et sur liquides biopsiques dans le cancer prostatique.

INTRODUCTION: Nowadays, diagnostic biomarker research is oriented on a genomic characterisation of prostate cancer (PCa). This study evaluated diagnostic values of TMPRSS2-Erg fusion transcripts expression (TE) and androgen receptor variant 7 (AR-V7) on urine (tU) and biopsic rince material (tLRB) samples. MATERIALS AND METHODS: TE and AR-V7 have been tested by RT-PCR and RT-qPCR on urine and biopsies' rince liquid on 372 patients referred for prostate biopsies. RESULTS: Two hundred thirty-three patients (62%) were diagnosed with PCa. tU.AR-V7 was positive for 15 healthy patients (28%) and 30 patients diagnosed with PCa (37%). tLRB.AR-V7 was positive for 66 patients (42%) diagnosed with PCa. Concerning TE for patients diagnosed with PCa, tU was positive for 59 patients (54%) and tLRB for 132 (55%). TE and TE/AR-V7 combination were significantly associated with PCa (P<0.001), as tLRB.AR-V7 (P<0.001). Sensitivity and specificity for TE/AR-V7 combination for PCa were respectively: tU.TE/AR-V7 67% and 70%, tLRB.TE/AR-V7 68.8% and 71%, and, tUtLRB.TE/AR-V7 83% and 60%. There was no benefit for AR-V7 and TE association versus TE alone when comparing AUC. CONCLUSION: AR-V7 is not specific of PCa because of detection on healthy patients. This study did not managed to show a sufficient diagnostic value for TE/AR-V7 combination on urine and biospic rince material tests. LEVEL OF EVIDENCE: 3.

Prolactin decreases LPS-induced inflammatory cytokines by inhibiting TLR-4/NFκB signaling in the human placenta.

Prolactin (PRL) plays an important role in trophoblast growth, placental angiogenesis and immunomodulation within the feto-maternal interface, where different cell types secrete PRL and express its receptor. During pregnancy, inflammatory signalling is a deleterious event that has been associated with poor fetal outcomes. The placenta is highly responsive to the inflammatory stimulus; however, the actions of PRL in placental immunity and inflammation remain largely unknown. The aim of this study was to evaluate PRL effects on the TLR4/NFkB signalling cascade and associated inflammatory targets in cultured explants from healthy term human placentas. An in utero inflammatory scenario was mimicked using lipopolysaccharides (LPS) from Escherichia coli. PRL significantly reduced LPS-dependent TNF-α, IL-1ß and IL-6 secretion and intracellular levels. Mechanistically, PRL prevented LPS-mediated upregulation of TLR-4 expression and NFκB phosphorylation. In conclusion, PRL limited inflammatory responses to LPS in the human placenta, suggesting that this hormone could be critical in inhibiting exacerbated immune responses to infections that could threaten pregnancy outcome. This is the first evidence of a mechanism for anti-inflammatory activity of PRL in the human placenta, acting as a negative regulator of TLR-4/NFkB signaling.

Prolactin (PRL) and its receptor: actions, signal transduction pathways and phenotypes observed in PRL receptor knockout mice.

PRL is an anterior pituitary hormone that, along with GH and PLs, forms a family of hormones that probably resulted from the duplication of an ancestral gene. The PRLR is also a member of a larger family, known as the cytokine class-1 receptor superfamily, which currently has more than 20 different members. PRLRs or binding sites are widely distributed throughout the body. In fact, it is difficult to find a tissue that does not express any PRLR mRNA or protein. In agreement with this wide distribution of receptors is the fact that now more than 300 separate actions of PRL have been reported in various vertebrates, including effects on water and salt balance, growth and development, endocrinology and metabolism, brain and behavior, reproduction, and immune regulation and protection. Clearly, a large proportion of these actions are directly or indirectly associated with the process of reproduction, including many behavioral effects. PRL is also becoming well known as an important regulator of immune function. A number of disease states, including the growth of different forms of cancer as well as various autoimmune diseases, appear to be related to an overproduction of PRL, which may act in an endocrine, autocrine, or paracrine manner, or via an increased sensitivity to the hormone. The first step in the mechanism of action of PRL is the binding to a cell surface receptor. The ligand binds in a two-step process in which site 1 on PRL binds to one receptor molecule, after which a second receptor molecule binds to site 2 on the hormone, forming a homodimer consisting of one molecule of PRL and two molecules of receptor. The PRLR contains no intrinsic tyrosine kinase cytoplasmic domain but associates with a cytoplasmic tyrosine kinase, JAK2. Dimerization of the receptor induces tyrosine phosphorylation and activation of the JAK kinase followed by phosphorylation of the receptor. Other receptor-associated kinases of the Src family have also been shown to be activated by PRL. One major pathway of signaling involves phosphorylation of cytoplasmic State proteins, which themselves dimerize and translocate to nucleus and bind to specific promoter elements on PRL-responsive genes. In addition, the Ras/Raf/MAP kinase pathway is also activated by PRL and may be involved in the proliferative effects of the hormone. Finally, a number of other potential mediators have been identified, including IRS-1, PI-3 kinase, SHP-2, PLC gamma, PKC, and intracellular Ca2+. The technique of gene targeting in mice has been used to develop the first experimental model in which the effect of the complete absence of any lactogen or PRL-mediated effects can be studied. Heterozygous (+/-) females show almost complete failure to lactate after the first, but not subsequent, pregnancies. Homozygous (-/-) females are infertile due to multiple reproductive abnormalities, including ovulation of premeiotic oocytes, reduced fertilization of oocytes, reduced preimplantation oocyte development, lack of embryo implantation, and the absence of pseudopregnancy. Twenty per cent of the homozygous males showed delayed fertility. Other phenotypes, including effects on the immune system and bone, are currently being examined. It is clear that there are multiple actions associated with PRL. It will be important to correlate known effects with local production of PRL to differentiate classic endocrine from autocrine/paracrine effects. The fact that extrapituitary PRL can, under some circumstances, compensate for pituitary PRL raises the interesting possibility that there may be effects of PRL other than those originally observed in hypophysectomized rats. The PRLR knockout mouse model should be an interesting system by which to look for effects activated only by PRL or other lactogenic hormones. On the other hand, many of the effects reported in this review may be shared with other hormones, cytokines, or growth factors and thus will be more difficult to study. (ABSTRACT TRUNCATED)

Bone homeostasis in growth hormone receptor-null mice is restored by IGF-I but independent of Stat5.

Growth hormone (GH) regulates both bone growth and remodeling, but it is unclear whether these actions are mediated directly by the GH receptor (GHR) and/or IGF-I signaling. The actions of GH are transduced by the Jak/Stat signaling pathway via Stat5, which is thought to regulate IGF-I expression. To determine the respective roles of GHR and IGF-I in bone growth and remodeling, we examined bones of wild-type, GHR knockout (GHR(-/-)), Stat5ab(-/-), and GHR(-/-) mice treated with IGF-I. Reduced bone growth in GHR(-/-) mice, due to a premature reduction in chondrocyte proliferation and cortical bone growth, was detected after 2 weeks of age. Additionally, although trabecular bone volume was unchanged, bone turnover was significantly reduced in GHR(-/-) mice, indicating GH involvement in the high bone-turnover level during growth. IGF-I treatment almost completely rescued all effects of the GHR(-/-) on both bone growth and remodeling, supporting a direct effect of IGF-I on both osteoblasts and chondrocytes. Whereas bone length was reduced in Stat5ab(-/-) mice, there was no reduction in trabecular bone remodeling or growth-plate width as observed in GHR(-/-) mice, indicating that the effects of GH in bone may not involve Stat5 activation.

A four-generation Ehlers-Danlos syndrome with vascular dissections. Skin ultrastructure and biomechanical properties.

Ehlers-Danlos syndrome (EDS) is heterogenous with regard to genetic traits, clinical manifestation, the biomechanical and microscopic properties of connective tissues, and basic molecular defects. We report on nine relatives of four generations who suffered from large vessel dissections and cutaneous microscopic changes consistent with EDS. Measurements of the mechanical properties of skin were performed using a computerized suction device (Cutometer). Morphological and biomechanical alterations suggestive of EDS were present in all examined subjects. A loose network of collagen bundles was admixed with clumsy elastic fibres. Factor XIIIa-positive dermal dendrocytes looked almost normal but were slim and rarefied in four subjects. The severity in ultrastructural alterations of the collagen network differed among the subjects. The group with the most prominent changes showed the most striking biomechanical alterations characterized by increased biologic elasticity without any excess in skin extensibility. A positive correlation was found between skin extensibility and elasticity. In conclusion, distinct alterations in the collagen scaffolding were found to be correlated to variable severity in biomechanical alterations of the skin. The predictive value of these changes for large vessel dissections in some families at risk remains to be settled.

[How I explore...cheilitis]. / Comment j'explore...une chéilite.

A cheilitis is an inflammatory disease confined to the lips. Several origins are recognized. Their nature is often different in children and adults. Some are spongiotic due to irritation or allergic reaction. Other lesions are keratotic and can evolve to leucoplasia and epidermoid carcinoma.

[How I treat...acne in adolescents: a strategic algorithm without antibiotic]. / Comment je traite...l'acné de l'adolescent: un algorithme stratégique sans antibiotique.

Acne is a multifaceted disorder. Its clinical presentation differs according to the age and gender of the subjects. Acne of the adolescent is a frequent disorder. Some topical and oral antibiotics have proven their efficacy. However, the risk of bacterial resistance may be a concern for the clinicians and their patients. Hence, a therapeutic strategy without antibiotics merits to be considered. Retinoids have a place of choice in this therapeutic strategy. Benzoyl peroxide and miconazole are also active and valuable agents in this therapeutic algorithm.

Human prolactin (hPRL) antagonists inhibit hPRL-activated signaling pathways involved in breast cancer cell proliferation.

The involvement of human prolactin (hPRL) in breast cancer has been recently reconsidered based on its autocrine/paracrine proliferative effect described in human mammary tumor epithelial cells. Therefore, there is growing interest in the development of potent hPRL antagonists that may inhibit this effect. We previously designed hPRL analogs displaying antagonistic properties in a human transcriptional bioassay. We now report that the most potent of those analogs, G129R-hPRL, antagonizes all hPRL-induced effects analysed in various breast cancer cell lines, including cell proliferation. The analog per se lacks intrinsic agonistic activity on PRL receptor-activated signaling cascades, cell proliferation and apoptosis, indicating that its mode of action only occurs through competitive inhibition of hPRL. We provide some molecular basis of this antagonistic effect by demonstrating that G129R-hPRL competitively inhibits hPRL-activation of the JAK-STAT and MAPK pathways, two signaling cascades involved in the mitogenic effect of hPRL in mammary epithelial cells. This competitive inhibition persists for at least 48 h, as evidenced by long term analysis of STAT5b activation or of progression through cell cycle. These results are the first demonstration at the molecular level that hPRL antagonists interfering with receptor dimerization disrupt signaling events in breast cancer cells, which prevents hPRL-induced cell proliferation.

Breast inflammatory gigantomastia in a context of immune-mediated diseases.

CONTEXT: Localized breast lesions have been described in lupic or diabetic patients. However, the description of breast gigantomastia in women presenting with autoimmune diseases has not been reported. SETTING: The study took place within the Department of Endocrinology and Reproductive Medicine, Necker Hospital, Paris, France. PATIENTS: We describe eight patients with inflammatory gigantomastia, occurring in a context of immune-mediated diseases: myasthenia, chronic arthritis, or thyroiditis. MAIN OUTCOME MEASURES: Together with hormonal, immunological, and breast magnetic resonance imaging (MRI) evaluation, breast histology enabled us to perform immunocytochemical and indirect immunofluorescence studies. Control sera were obtained from patients with (n = 10) and without (n = 7) antinuclear antibodies. RESULTS: Six of the eight patients developed gigantomastia either at puberty or during pregnancy. Neither a hormonal oversecretion nor a specific immunological pattern was observed. All patients except one presented antinuclear antibodies. Histological study revealed a diffuse, stromal hyperplasia and a severe atrophy of the lobules. A rarefaction of adipocytes was also noted, as previously suggested on MRI. There was a perilobular lymphocytic infiltrate made of CD3+ lymphocytes. Study of sera from five of six cases of gigantomastia showed a nuclear immunofluorescence pattern in normal mammary ductal and lobular glandular epithelium, as well as in kidney and intestine epithelial cells. In control sera, a nuclear signal was observed only when antinuclear antibodies were present. CONCLUSIONS: We suggest that breast tissue may be a target tissue in autoimmune diseases, this process being favored by the hormonal milieu. However, the precise mechanism of such association is not individualized. The fact that stromal hyperplasia is the main histological feature justifies the search for the involvement of growth factors in such a process.

Alanine-scanning mutagenesis of human prolactin: importance of the 58-74 region for bioactivity.

We have generated 10 alanine mutants of human PRL (hPRL), a member of the PRL/GH family, to investigate the involvement of the highly conserved 58-74 region in the biological behavior of the protein. When treated with polyclonal anti-hPRL antibodies, all mutants were immunologically indistinguishable from the unmodified hPRL, and circular dichroism analyses indicated that their alpha-helix content was similar to that of the unmodified hormone. Mutations C58A, K69A, and, to a lesser extent, P66A affected drastically the ability of hPRL first to bind to the lactogenic receptor and second to stimulate the proliferation of Nb2 lymphoma cells, proving the importance of the 58-74 peptide segment for hPRL bioactivity. Binding affinities of these mutants to the Nb2 lactogenic receptor have been compared to lactogenic binding data previously obtained for several mutants of hGH. The comparison reveals that the residues involved in the biological properties of the two proteins are not at topologically equivalent positions. Hence, we suggest that the binding of these hormones to the lactogenic receptors occurs through a different molecular mechanism having distinct requirements at the residue level.

Convergence of signaling transduced by prolactin (PRL)/cytokine chimeric receptors on PRL-responsive gene transcription.

Ligand binding to cytokine receptors rapidly triggers tyrosine phosphorylation of Janus family tyrosine kinases (Jaks) and signal transducers and activators of transcription (Stats). Jak2 activation is mediated by PRL receptor homodimers as well as by receptors for the interleukin (IL)-3, IL-5, and granulocyte macrophage-colony stimulating factor, which share the common beta c-subunit. Otherwise, Jak1 and Jak3 are involved in IL-2 signaling through heterodimerization of the IL-2 receptor-beta (IL-2R beta) and gamma c-chains. Stat5, a member of the Stat family, confers the PRL response on milk protein genes. Here we show that chimeric PRL receptors that contain the transmembrane and cytoplasmic domains of the IL-2R beta or beta c-chains transduce in response to PRL tyrosine phosphorylation and activation of Jak1 and Jak2, respectively. Tyrosine phosphorylation of Stat5, activation of its DNA-binding activity assessed in bandshift experiments using a lactogenic hormone responsive region (LHRR) probe, and transcriptional induction of a beta-casein promoter luciferase construct in stably transfected CHO cells are observed with both chimeras upon PRL stimulation. Our results demonstrate that distinct cytoplasmic domains of these cytokine receptors elicit convergent signaling pathways and provide evidence that beta c and IL-2R beta function as a complete signal transducer. Our data strengthen previous observations that Stat5 activation is not dependent on the activation of a specific Jak kinase and also suggest that neither Jak3 nor gamma c have a specific role in this process.

[Photoexacerbated dermatoses]. / Dermatoses photo-aggravées.

A series of viral and bacterial diseases are photoaggravated. Some autoimmune connective tissue disorders including lupus erythematosus and dermatomyositis are also affected. This category of photoexacerbated diseases also encompasses some cases of atopic dermatitis, lichen and rosacea.

[Laser and pulsed light treatments]. / Traitements par lasers et lumiere pulsée.

Numerous types of lasers can exert different and specific effects in the skin. Devices delivering high intensity of pulsed light can exert similar effect.

The human growth hormone antagonist B2036 does not interact with the prolactin receptor.

The human growth hormone (hGH) antagonist B2036 combines a single amino acid substitution impairing receptor binding site 2 (G120K) with eight additional amino acid substitutions that improve binding site 1 affinity. This hGH antagonist is being tested for treating pathologies linked to excess hGH levels. B2036-PEG is a polyethylene glycol (PEG) conjugated form of B2036 that has an increased half-life due to reduced renal clearance. It is currently in phase III trials for acromegaly. Human GH is also able to bind to the receptor of prolactin (PRLR). Since activation of PRLR can promote an array of pathological states (reproduction disorders, breast cancer), the ability of B2036-PEG to interact with the PRLR had to be determined. In this study, we compared four hGH antagonists (G120K, G120K-PEG, B2036 and B2036-PEG) in three bioassays: proliferation of rat Nb2 cells, binding to the human PRLR and activation of human PRLR-mediated signaling in a cell line stably expressing this receptor and a luciferase reporter gene. Agonistic and antagonistic properties were characterized. Our data show that B2036-PEG does not bind, activate or antagonize PRLRs, either from rat or human origin. These observations further demonstrate that the eight amino acid substitutions within binding site 1 provide binding specificity directed towards the human GH receptor.

Biological activity and immunological reactivity of human prolactin mutants.

We examined the biological activity and immunological reactivity of four mutants of human PRL. Two were mutants that changed the ability of human PRL to inhibit rat PRL storage when transfected into a rat pituitary cell line:mutations S34A and N31T. Two mutations were in regions of PRL that are highly conserved. One, des(3-11)-PRL, removed the N-terminal cystine loop that most PRLs, except those from certain fish, have, and no GHs have. The other, S90A, mutated a serine that is present in all PRLs but those from some fish and in all GHs. The immunological properties of des(3-11)-PRL were reduced 10-fold compared to those of wildtype human PRL in a RIA using NIH antihuman PRL-3, AFP C11580; the others were similar to those of wild-type PRL. The biological activity of des(3-11)-PRL was the most affected; activity was reduced about 8-fold compared to that of wild-type PRL in the Nb2 cell assay. The activities of the others were similar to that of the wild type. Serine 90 may be partially buried by loops connecting the alpha-helixes. The mutation of serine 90 did not affect the stability of the molecule in vitro, determined by comparing the red shift in tryptophan fluorescence that occurs with increasing concentrations of urea in S90A and wild-type PRL. The activity of S34A and N31T mutations indicates there is no correlation between biological activity and ability to affect storage. The N-terminal cystine loop may be conserved because it is needed for biological activity, but the conservation of serine 90 in GH and PRL must be determined by other properties, such as spacial requirements.

S179D-human PRL, a pseudophosphorylated human PRL analog, is an agonist and not an antagonist.

For many years, our group has been involved in the development of human PRL antagonists. In two recent publications, S179D-human PRL, a human PRL analog designed to mimic a putative S179-phosphorylated human PRL, was reported to be a highly potent antagonist of human PRL-induced proliferation and signaling in rat Nb2 cells. We prepared this analog with the aim of testing it in various bioassays involving the homologous, human PRL receptor. In our hands, S179D- human PRL was able to stimulate 1) the proliferation of rat Nb2 cells and of human mammary tumor epithelial cells (T-47D), 2) transcriptional activation of the lactogenic hormone response element-luciferase reporter gene, and 3) activation of the Janus kinase/signal transducer and activator of transcription and MAPK pathways. Using the previously characterized antagonist G129R-human PRL as a control, we failed to observe any evidence for antagonism of S179D-human PRL toward any of the human PRL-induced effects analyzed, including cell proliferation, transcriptional activation, and signaling. In conclusion, our data argue that S179D-human PRL is an agonist displaying slightly reduced affinity and activity due to local alteration of receptor binding site 1, and that the antagonistic properties previously attributed to S179D-human PRL cannot be confirmed in any of the assays analyzed in this study.

Osteoblasts are a new target for prolactin: analysis of bone formation in prolactin receptor knockout mice.

Bone development is a multistep process that includes patterning of skeletal elements, commitment of hematopoietic and/or mesenchymental cells to chondrogenic and osteogenic lineages, and further differentiation into three specialized cell types: chondrocytes in cartilage and osteoblasts and osteoclasts in bone. Although PRL has a multitude of biological actions in addition to its role in the mammary gland, very little is known about its effect on bone. Mice carrying a germline null mutation for the PRL receptor gene have been produced in our laboratory and used to study the role of PRL in bone formation. In -/- embryos, we observed an alteration in bone development of calvaria. In adults, histomorphometric analysis showed that the absence of PRL receptors leads to a decrease in bone formation rate using double calcein labeling and a reduction of bone mineral density, measured by dual energy x-ray absorptiometry. In addition, serum estradiol, progesterone, testosterone, and PTH levels were analyzed. We also established that osteoblasts, but not osteoclasts, express PRL receptors. This suggests that an effect of PRL on osteoblasts could be required for normal bone formation and maintenance of bone mass. Thus, the PRL receptor knockout mouse model provides a new tool to investigate the involvement of PRL in bone metabolism.

Homodimerization of IL-2 receptor beta chain is necessary and sufficient to activate Jak2 and downstream signaling pathways.

Cytokine receptor signaling involves the Jak/Stat pathways. Heterotrimeric IL-2R (alpha, beta, gamma[c] chains) activates Jak1 and Jak3, whereas homodimeric PRLR activates Jak2. The requirements directing such specificity of Jak activation are unknown. We show that chimeric receptors containing the intracellular domain of IL-2Rbeta chain fused to the extracellular domain of either EPOR or Kit, a non-cytokine receptor, activate Jak2. This observation provides evidence that IL-2Rbeta intrinsically possesses the ability to activate Jak2, but that this property is only displayed in homodimerized complexes. Our data suggest a role for the stoichiometry of cytokine receptors in selective activation of Janus kinases.

A mutant receptor with enhanced dominant-negative activity for the blockade of human prolactin signalling.

An effective mechanism for interfering with prolactin signalling would provide a powerful tool for clarifying the importance of prolactin in breast cancer, as well as for investigating functions of prolactin in other tissues. Based on our previous identification of a dominant-negative mutation in the growth hormone receptor that causes familial short stature, we investigated the potential for using a similar truncated mutant of the prolactin receptor (PRLR1-242). Like the mutant growth hormone receptor, PRLR1-242 exerts an exceptionally powerful dominant-negative effect. A probable explanation for the strong dominant-negative activity of this class of mutation is that, lacking internalisation motifs, the truncated mutants accumulate at the cell surface and form non-functional heterodimers with wild-type receptors. In accordance with evidence for heterodimer formation between the two receptors, PRLR1-242 also blocks signalling by the growth hormone receptor. When expressed from an adenoviral vector, PRLR1-242 inhibits activation of STAT5 (signal transducer and activator of transcription 5) by prolactin in T47-D breast cancer cells, and blocks the ability of prolactin to induce proliferation in these cells. Thus PRLR1-242 provides an effective means of blocking the responsiveness of target tissues to human prolactin.

Involvement of prolactin in breast cancer: redefining the molecular targets.

The mammary gland is the major target tissue of prolactin (PRL) in mammals. Although this pituitary hormone has been long suspected to be involved in the progression of human breast cancer, the failure of clinical improvement by treatment with dopamine agonists (which lower circulating levels of PRL) rapidly reduced the interest of oncologists concerning a potential role of PRL in the development of breast cancer. Within the last few years, however, several studies reported first, that PRL is also synthesized by mammary epithelial cells, and second that it may exert a proliferative action in an autocrine/paracrine manner. In agreement with a recent epidemiological study, these observations have led to a reconsideration of the role of PRL as an active participant in breast cancer, and are an impetus to redefine the molecular targets of anti-prolactin strategies since dopamine analogs are assumed to be inefficient on extrapituitary PRL synthesis. In this review, we briefly summarize the current knowledge of PRL effects on both normal and tumor mammary cells, and we discuss the most relevant articles supporting the autocrine-paracrine action of PRL in the breast. With the aim of defining putative new molecular targets, we propose an overview of the main PRL receptor signaling cascades known to be triggered by PRL in mammary epithelial cells or, when not available, in other cell types. Finally, because proteolytic fragments of rat PRL have been shown to inhibit the angiogenic process, which may be relevant for preventing the progression of solid tumors such as breast tumors, we discuss the hypothesis that the enzymatic cleavage of human PRL could also represent a new molecular target in the search for alternative strategies in the treatment of breast cancer.