MSR1 repeats modulate gene expression and affect risk of breast and prostate cancer

Background

MSR1 repeats are a 36-38 bp minisatellite element that have recently been implicated in the regulation of gene expression, through copy number variation (CNV).

Patients and methods

Bioinformatic and experimental methods were used to assess the distribution of MSR1 across the genome, evaluate the regulatory potential of such elements and explore the role of MSR1 elements in cancer, particularly non-familial breast cancer and prostate cancer.

Results

MSR1s are predominately located at chromosome 19 and are functionally enriched in regulatory regions of the genome, particularly regions implicated in short-range regulatory activities (H3K27ac, H3K4me1 and H3K4me3). MSR1-regulated genes were found to have specific molecular roles, such as serine-protease activity (P = 4.80 × 10-7) and ion channel activity (P = 2.7 × 10-4). The kallikrein locus was found to contain a large number of MSR1 clusters, and at least six of these showed CNV. An MSR1 cluster was identified within KLK14, with 9 and 11 copies being normal variants. A significant association with the 9-copy allele and non-familial breast cancer was found in two independent populations (P = 0.004; P = 0.03). In the white British population, the minor allele conferred an increased risk of 1.21-3.51 times for all non-familial disease, or 1.7-5.3 times in early-onset disease. The 9-copy allele was also found to be associated with increased risk of prostate cancer in an independent population (odds ratio = 1.27-1.56; P =0.009).

Conclusions

MSR1 repeats act as molecular switches that modulate gene expression. It is likely that CNV of MSR1 will affect risk of development of various forms of cancer, including that of breast and prostate. The MSR1 cluster at KLK14 represents the strongest risk factor identified to date in non-familial breast cancer and a significant risk factor for prostate cancer. Analysis of MSR1 genotype will allow development of precise stratification of disease risk and provide a novel target for therapeutic agents.

Dermoscopy and direct immunofluorescence findings of elastosis perforans serpiginosa

Elastosis perforans serpiginosa (EPS) is a rare skin disorder characterized by transepidermal elimination of abnormal elastic fibres. We present a new case of D-penicillamine (DPA)-induced EPS, and describe the clinical, dermoscopic, histopathological and direct immunofluorescence (DIF) findings. A 33-year-old woman receiving treatment with DPA presented with annular skin lesions. Digital dermoscopy of the lesions showed a central area of pink and yellowish discolouration with keratotic papules in the periphery, surrounded by a white halo, disposed in a way that resembled the islands of an archipelago. Other lesions showed a white to yellow central colouration and 'chrysalides' surrounding the keratotic plugs. Linear and granular deposits of IgG attached to the abnormal elastic fibres were seen with DIF. Dermoscopy can be helpful in the diagnosis of EPS. Moreover, DIF findings in skin biopsies of this case support the immune-mediated pathogenesis of EPS.

Effects of anabolic implants of oestradiol alone or in combination with trenbolone acetate on the ultrastructure of mammary glands in female lambs regarding their interference in prolactin secretion

The side-effects of anabolic steroid implants on mammary gland ultrastructure were evaluated in female lambs treated with oestradiol (n = 10) and with oestradiol plus trenbolone acetate (n = 10). Ten non-implanted lambs were used as controls. Apart from the ultrastructural study of the mammary gland, an assessment of the prolactin pituitary cell population was carried out by immunological methods. Our results showed that oestrogenic implants exert stimulating effects on mammary gland development, both by activating the synthesis process at mammary gland cell levels and by increasing prolactin pituitary production. Nevertheless, there was no evidence of secretory products in the lumen of the gland. Implants containing trenbolone acetate counteracted the mammary stimulus of oestrogens showing ultrastructural images of cell autolysis and necrosis.

Expression of 3 beta-hydroxysteroid dehydrogenase/isomerase in the female rat pituitary

3 beta-Hydroxysteroid dehydrogenase/isomerase (3 beta-HSD) catalyses an essential step in the biosynthesis of steroid hormones and is widely distributed in peripheral steroid target organs. The present report describes for first time the expression of this enzyme in the pituitary of female rats. Immunohistochemistry at the light microscopic level was performed on pro-oestrous and ovariectomized rat pituitaries. Immunoreactive cells were scattered and randomly distributed throughout the anterior lobe, whereas cells located in the posterior lobe and pars intermedia were immunonegative. Differences were observed in cell morphology and in the number of 3 beta-HSD-immunopositive cells between ovariectomized and pro-oestrous female rat pituitaries, suggesting that steroidogenic activity is affected by ovarian endocrine function. Apart from adenohypophyseal immunoreactive cells, 3 beta-HSD immunopositivity was also noted in endothelial cells of almost all pituitary capillaries located in the anterior and posterior lobes.

Changes in estrogen receptor expression and cell activity of lactotropes in female mink (Mustela vison) pituitary in response to variations in the gonadal steroid environment

This study was undertaken to get new information on the role played by estrogen (E) on the activity of mink lactotropes. Immunocytochemistry for estrogen receptor (ER) and prolactin (PRL) was applied to assess modifications in the protein production that occur as a result of in vivo changes in the gonadal steroid environment. Variations in the functional activity of lactotropes were demonstrated from the ultrastructural characteristics and morphometric parameters (cellular area, numerical density, and secretory granular size). The present study documents the presence of ER in mink lactotropes revealing the ability of E to regulate the expression of ER in the mink pituitary. Furthermore, all morphological and morphometric parameters of lactotropes activity appeared significantly increased in intact females, killed during the mating period, compared with castrated females under the same photoperiodic conditions. Castration thus blocks the stimulatory effect of photoperiod on metabolic activity of mink lactotropes suggesting that E may participate in the photoperiodic regulation of PRL.

Simultaneous localization of Pit-1 protein and gonadotropins on the same cell type in the anterior pituitary glands of the rat

Pit-1 is a prototypic member of the POU transcription factor family and plays a critical role in pituitary-specific action of growth hormone (GH), prolactin (PRL), and thyroid-stimulating hormone (TSH) beta-subunit genes. The purpose of the present study was to elucidate the changes in the expression of the Pit-1 product in the pituitary of pregnant rats employing an improved double-immunohistochemical method. The positive cells showed nuclear immunoreactivity and Pit-1 protein was frequently observed in the nuclei of many cells which were also immunopositive for GH, PRL, and betaTSH. Unexpectedly, a significant number of pituitary cells containing both Pit-1 and gonadotropins were also observed. These cells were usually distributed near blood vessels that supply the pituitary. While a prominent increase in the percentage of Pit-1/PRL, Pit-1/beta-luteinizing hormone and Pit-1/beta-follicle-stimulating hormone immunoreactive cells was observed in pregnant rats, the percentage of Pit-1/GH immunoreactive cells was strongly decreased. In contrast, no significant differences in the percentage of Pit-1/betaTSH doubly immunolabeled cells were noticed. Our findings strongly support the hypothesis that PRL could coexist in the Pit-1 immunopositive gonadotropes. Although Pit-1 protein was not detected in the nuclei of corticotropes, the existence of these cells in the rat pituitary cannot be excluded.

Description of two types of mammosomatotropes in mink (Mustela vison) adenohypophysis: changes in the population of mammosomatotropes under different physiological conditions

The present study was undertaken to clarify the existence of mammosomatotropes (MS cells) in the mink adenohypophysis and their possible involvement in the interconversion of mammotrope and somatotrope cells under different physiological conditions: prepubertal, pubertal and adulthood. Electron microscope immunocytochemistry was used to detect growth hormone (GH) and prolactin (PRL) immunoreactivities in the anterior pituitary gland of mink. Primary antisera raised in rabbit (human anti-GH, NIDDK-AFP-1613102481; human anti-PRL, NIDDK-AFP-55781789) were localized with appropriate species-specific antisera coupled to colloidal gold particles of different sizes. MS cells were most frequently observed in adult mink. Double labeling for GH and PRL was presented in two types of MS cells. MS1 cells, observed only in adults, showed an irregular morphology, with many cytoplasmic processes. Within their cytoplasm there were numerous rounded secretory granules of approximately 135 nm mean diameter. In MS1 cells three types of secretory granules were identified. The most numerous contained only PRL. The least frequent contained only GH and the third type contained GH and PRL and appeared in an intermediate quantity. MS2 cells, observed in all age groups, presented a rounded morphology. These cells had a voluminous cytoplasm which showed little development of the organelles and contained a large number of rounded and very electron-dense secretory granules which measured about 160 nm mean diameter. Within MS2 cells two types of secretory granules, according to their immunolabeling, were observed. Monohormonal granules containing GH were the more abundant while bihormonal granules, containing GH and PRL, were present to a lesser degree. Data presented in this report suggest that MS cells could play a role in the interconversion of somatotropes into mammotropes in mink.

Ultrastructural and immunocytochemical studies of prolactin-secreting cells in adenohypophysis of the mink (Mustela vison)

This investigation aimed to identify, by the double immunogold procedure, the ultrastructural characteristics of prolactin (PRL) cells in the mink. Such cells showed a marked pleomorphism and had a close topographic relationship with growth hormone cells. A common morphological characteristic of PRL cells in all stages of mink development was the presence of round secretory granules, in contrast to changes in the ultrastructural characteristics of PRL cells with physiological state and photoperiod. Thus PRL cells in prepubertal, pubertal, and sexually inactive adult mink, killed under a short-day photoperiod, showed little development of the organelles but a significantly increased cytoplasmic electron density. In sexually active mink and in lactating females under long-day conditions, PRL cells had a highly developed cytoplasmic organelle structure consisting mainly of rough endoplasmic reticulum. The morphometric study demonstrated that the mean diameter of the secretory granules similarly varied in both sexes. Pubertal mink had PRL cells with smaller secretory granules (female 74.1 +/- 0.6 nm, male 80.4 +/- 1.7 nm), whereas adult mink killed under a long-day photoperiod presented PRL cells with larger secretory granules (female 194.5 +/- 2.2 nm, male 203.3 +/- 1.7 nm). The changes in the ultrastructural characteristics of PRL cells during the annual cycle suggest a photoperiodic influence upon these cells. In addition the heterogeneity in ultrastructural characteristics and storage characteristics of PRL in some adult mink may suggest a varying metabolic role for PRL under certain, as yet not fully characterized, conditions.

Immunohistochemical identification and morphometric study of ACTH cells of mink (Mustela vison) during growth and different stages of sexual activity in the adult

The morphological characteristics and changes in the cellular area and volume density of ACTH cells have been examined in the mink from the first half of the suckling period to adulthood and in the adult mink at different stages of the sexual cycle. ACTH cells were identified immunohistochemically (avidin-biotin complex) and applied over semithin sections. Unlike in suckling and prepubertal mink, there was a clear topographic relation between adenohypophysial follicles and ACTH cells in pubertal and adult animals. The ACTH cells presented a morphological pleomorphism, appearing from oval or round to stellate or angular. The morphometric study demonstrated that the cellular area and volume density of ACTH cells varied during growth and in adult mink there were sexual variations. Gonadal steroids may influence ACTH cells especially in females, in which there were variations before and after puberty. The heterogeneity in size, shape, secretion, and storage parameters of the ACTH cells could explain the presence, in some of the groups studied, of an increased or decreased cellular area, while the volume density remained unchanged.

Effects of acute administration of growth hormone-releasing hormone (GHRH) and oxytocin on somatotroph cells in sheep: morphometric study and growth hormone (GH) secretion

In this work, the combined use of the morphometric study of somatotroph cells and plasma GH levels provided new data for the interpretation of the role played by OT and GHRH on GH cells. GHRH 1-29 (15 micrograms/kg), oxytocin (2.5 IU animal) or 1 ml saline solution were administered to male lambs. The GH plasma concentration was measured by RIA and for the morphometric study the cellular area, nuclear area and volume density of the somatotroph cells were measured in 1 micron semi-thin sections immunolabeled with avidin-biotin technique (ABC). The area under the GH response curve for 3 hours after injection was similar in both saline and OT-treated animals (24.8 +/- 9.1 and 31.4 +/- 14.7 micrograms/ml, respectively) and much lower than that observed in GHRH-treated animals (445.5 +/- 126.7 micrograms/ml). The cell area of somatotrophs was smaller in the GHRH-treated lambs and larger in the OT-treated lambs than in the control lambs (71.47 +/- 1.56, 91.42 +/- 1.72 and 83.1 +/- 1.74 microns 2, respectively). A similar change was observed in the nuclear area; it decreased in the GHRH-treated lambs (21.61 +/- 0.52 microns 2) and increased in the OT-treated lambs (25.45 +/- 0.68 microns 2) with respect to the control group (23.75 +/- 0.44 microns 2). No significant differences were found in volume density.(ABSTRACT TRUNCATED AT 250 WORDS)

An easy method for the removal of Epon resin from semi-thin sections. Application of the avidin-biotin technique

A simple procedure is described for removing Epon resin from semi-thin 1 micron sections, which permits excellent postembedding immunohistochemical staining (avidin-biotin complex technique). The procedure was developed for the detection of growth hormone and prolactin in bovine adenohypophysis fixed with 2% paraformaldehyde and 0.5% glutaraldehyde in 0.1 M sodium cacodylate buffer pH 7.4-7.6. The results indicate that the removal of the epoxy embedding medium prior to the application of the immunohistochemical reagents was essential for the successful localization of the antigenic determinants of the two hormones. The immunocytochemical reactivity was obtained only after treating the sections with a solution of potassium hydroxide in a mixture of absolute methyl alcohol and propylene oxide (Maxwell's solution). An enhanced immunoreactivity was obtained when this treatment was followed by an additional treatment with either 4% hydrogen peroxide or a saturated aqueous solution of sodium metaperiodate. Because of the easy preparation of the Epon removal solution and the good structural preservation without damage to the antigenic determinants, Maxwell's solution is suggested as a good etching agent which can be used in immunohistochemical studies on semi-thin sections with excellent results.

Presence of mammosomatotropic (MS) cells in mink (Mustela vison) adenohypophysis

This study was undertaken to investigate the presence of mammosomatotrophs (MS) cells in the suckling mink. Using the double immunolabeling procedure, with colloidal gold as label, we demonstrated the existence of MS cells in these animals. Only one type of MS cells has been observed. These cells showed a great morphological similarity to classic prolactin (PRL) cells. MS cells of suckling mink were pleomorphic in appearance with many processes, their nuclei were irregular and their Golgi apparatus and endoplasmic reticulum were poorly developed. Their secretory granules were small (about 144 nm in mean diameter) and round. Two types of secretory granules have been found: monohormonal including PRL (the more frequent) and growth hormone (GH) (very scanty) granules, and bihormonal granules distributed between the former. We propose that MS cells of the mink, like other species, could represent an intermediate cell type in the transformation process of GH cells into PRL cells.

Immunocytochemical study of the growth hormone and prolactin pituitary cells in male and female suckling mink

Adenohypophyseal growth hormone (GH) and prolactin (PRL) cells of suckling mink of both sexes at different stages of lactation were studied by the immunogold method and morphometry for electron microscopy. Hypophyses were perfused with fixative, postfixed in osmium tetroxide, and embedded in Epon 812. Ultrathin sections were labeled by the immunogold method with anti-human GH and anti-human PRL sera. Two PRL cell types were identified based on their morphology and the development of cytoplasmatic organelle. Significant differences in the granular sizes of GH and PRL cells were found between males and females at different stages of suckling. The results suggest that the changes in secretion and storage in GH and PRL cells of suckling mink during lactation depend upon sex and age, and that the granular polymorphism is not an unequivocal criterion for the identification of PRL cells in suckling mink.

[Progeny in women with fetal alcohol syndrome]

Among children referred to our genetic clinics for mental or growth retardation we identified 8 of their mothers with the fetal alcohol syndrome. This was complete in 5 and partial in 3. All of their alcoholic mothers had died. Most of the patients were unwed mothers with mental retardation and no elementary education. One of them was also alcoholic and her third offspring had the syndrome. The etiology of this syndrome and possible preventive measures are discussed.

Antiemetic efficacy of escalating doses of alizapride against chemotherapy-induced emesis

The antiemetic effect of a new benzamide, alizapride, was investigated with escalating doses through four levels starting at 5 mg/kg/cycle up to 20 mg/kg/cycle. 39 patients were accrued who received cancer chemotherapy which included the following drugs in various combinations: cyclophosphamide, adriamycin, fluorouracil, carboplatin and etoposide (VP-16). Complete control of emesis was achieved in a third of the 39 patients. There was no statistically significant difference among the dose levels with regard to the patient's assessment of the incidence and severity of nausea and vomiting. Alizapride was well tolerated at all dose levels tested with minimal toxicity. Mild sedation was reported in 60% of the patients. Neither extrapyramidal reactions nor hypotensive side effects were observed. Thus the therapeutic yield of alizapride could be further studied concerning the optimal dose and schedule as well as its use in combination with other antiemetic drugs.

GNRH induces activation of Leydig-like cells in Pleurodeles waltlii. A morphometric study

The ultrastructure of the interstitial cells of the glandular tissue of Pleurodeles waltlii was studied in testis of animals obtained in early breeding season (January) under gonadotropic releasing hormone (GNRH) treatments and controls. These cells (parenchymal or Leydig-like cells) displayed the structural characteristics of steroid-producing cells. GNRH administration for 24 hours induced a significant decrease of both medial volume and volume density of lipid droplets. On the other hand, cell volume, nucleus, mitochondria, mitochondrial cristae and tubules of smooth endoplasmic reticulum were increased. The surface density of mitochondrial cristae was also increased.

Experimental study on alcoholics with an "inability to stop"

In previous papers (2, 3) we have set forth our neurophysiopathogenic theory of alcoholism, which is an amplification of Jellinek's hypothesis (1) that the gamma and delta types of alcoholism form an addictive disease. The physical dependence characterized by a state of distress and an overpowering desire to consume more ethanol, assumes three forms: (a)“inability to stop” the ingestion (Jellinek's “loss of control”) noted moments after ingesting a small quantity of ethanol following a period of abstinence, which characterizes the gamma or intermittent clinical form of alcoholism; (b)“inability to abstain” from ethanol hours after the last ingestion and after continuous drinking (each 4 to 8 hours during months or years), which characterizes the delta or inveterate clinical form of alcoholism, and (c)primary physical dependence without ethanol having necessarily been ingested previously, which characterizes remittent, or epsilon alcoholism or dipsomania.