IGFBP-3 methylation-derived deficiency mediates the resistance to cisplatin through the activation of the IGFIR/Akt pathway in non-small cell lung cancer

Although many cancers initially respond to cisplatin (CDDP)-based chemotherapy, resistance frequently develops. Insulin-like growth factor-binding protein-3 (IGFBP-3) silencing by promoter methylation is involved in the CDDP-acquired resistance process in non-small cell lung cancer (NSCLC) patients. Our purpose is to design a translational-based profile to predict resistance in NSCLC by studying the role of IGFBP-3 in the phosphatidyl inositol 3-kinase (PI3K) signaling pathway. We have first examined the relationship between IGFBP-3 expression regulated by promoter methylation and activation of the epidermal growth factor receptor (EGFR), insulin-like growth factor-I receptor (IGFIR) and PI3K/AKT pathways in 10 human cancer cell lines and 25 NSCLC patients with known IGFBP-3 methylation status and response to CDDP. Then, to provide a helpful tool that enables clinicians to identify patients with a potential response to CDDP, we have calculated the association between our diagnostic test and the true outcome of analyzed samples in terms of cisplatin IC50; the inhibitory concentration that kills 50% of the cell population. Our results suggest that loss of IGFBP-3 expression by promoter methylation in tumor cells treated with CDDP may activate the PI3K/AKT pathway through the specific derepression of IGFIR signaling, inducing resistance to CDDP. This study also provides a predictive test for clinical practice with an accuracy and precision of 0.84 and 0.9, respectively, (P=0.0062). We present a biomarker test that could provide clinicians with a robust tool with which to decide on the use of CDDP, improving patient clinical outcomes.

The interstitial lymphatic peritoneal mesothelium axis in portal hypertensive ascites: when in danger, go back to the sea

Portal hypertension induces a splanchnic and systemic low-grade inflammatory response that could induce the expression of three phenotypes, named ischemia-reperfusion, leukocytic, and angiogenic phenotypes.During the splanchnic expression of these phenotypes, interstitial edema, increased lymph flow, and lymphangiogenesis are produced in the gastrointestinal tract. Associated liver disease increases intestinal bacterial translocation, splanchnic lymph flow, and induces ascites and hepatorenal syndrome. Extrahepatic cholestasis in the rat allows to study the worsening of the portal hypertensive syndrome when associated with chronic liver disease. The splanchnic interstitium, the mesenteric lymphatics, and the peritoneal mesothelium seem to create an inflammatory pathway that could have a key pathophysiological relevance in the production of the portal hypertension syndrome complications. The hypothetical comparison between the ascitic and the amniotic fluids allows for translational investigation. From a phylogenetic point of view, the ancestral mechanisms for amniotic fluid production were essential for animal survival out of the aquatic environment. However, their hypothetical appearance in the cirrhotic patient is considered pathological since ultimately they lead to ascites development. But, the adult human being would take advantage of the potential beneficial effects of this “amniotic-like fluid” to manage the interstitial fluids without adverse effects when chronic liver disease aggravates.

Estrogen receptors alpha and beta in the normal, hyperplastic and carcinomatous human prostate

Two different estrogen receptors (ER-alpha and ER-beta) have been described, which are differentially involved in regulating the normal function of reproductive tissues. ER-alpha was considered for a long time to be the only estrogen receptor, and it has been detected in the stromal cells of the human prostate but not in the epithelium. To obtain new information about the differential effects of both receptor types, we have investigated their localization in normal prostates, benign prostatic hyperplasia (BPH), and prostatic cancer (PC) by immunohistochemistry, ELISA and Western blot. Epithelial immunostaining was absent in normal prostates and was present in BPH (10% of cells) and PC (80% of cells), whereas about 15% of stromal cells were positively immunostained for ER-alpha in the three types of prostatic specimens studied. Epithelial immunostaining for ER-beta was detected in normal prostates (13% of cells), BPH (30% of cells) and PC (79% of cells), whereas stromal immunostaining for ER-beta was absent in normal and hyperplastic prostates and was present in PC (12% of cells). The complementary presence of both receptor types in the normal prostate (ER-beta in the epithelium and ER-alpha in the stroma) might explain the mechanism of estrogen action in the development of BPH. The increased epithelial immunostaining for both ER-alpha and ER-beta in BPH and PC suggests that the involvement of estrogen receptors in hyperplasia and cancer concerns mainly the epithelium.

Immunoexpression of tumour necrosis factor-alpha and its receptors 1 and 2 correlates with proliferation/apoptosis equilibrium in normal, hyperplasic and carcinomatous human prostate

Immunohistochemical and semiquantitative study of TNF-alpha, its receptors types 1 (TNFR1) and 2 (TNFR2), cell proliferation (Ki-67 nuclear antigen), and apoptosis (Tunel method) was carried out in human prostates, in normal healthy conditions, as well as in benign prostatic hyperplasia (BPH) and prostatic carcinoma (PC). Cell proliferation was higher in BPH than in normal prostates, and even higher in PC, mainly in neoformations showing a microglandular pattern. The apoptotic index was similar in BPH and normal prostates, and increased significantly in PC with independence of the pattern. In BPH, immunoreaction to TNF-alpha decreased as compared with that of normal prostates, while immunoreactions to both TNF-alpha receptors increased. This suggests a feedback downregulation of the factor, and that the low TNF-alpha activity in BPH are compensated by the increased amount of receptors. In PC, immunoreaction to TNF-alpha and its two receptors increased markedly, suggesting that the TNF-induced effects are also increased. Contrarily to cell proliferation immunoexpression, PC reaction to TNFR2 was stronger in the papillar pattern than in the micrograndular pattern, and this suggests an inverse correlation between TNFR2 expression and cell proliferation.

Interferon-gamma and its functional receptors overexpression in benign prostatic hyperplasia and prostatic carcinoma: parallelism with c-myc and p53 expression

The therapeutic potential of IFN-gamma in prostatic cancer has been documented in several reports, although no immunohistochemical studies of this factor and its receptors in the prostate have been reported. The aim of the present study was to investigate the expression of IFN-gamma and its receptor components (IFN-gamma-Ralpha and IFN-gamma-Rbeta) in normal prostate, benign prostatic hyperplasia (BPH) and prostatic cancer (PC), as well as the possible relationship between this factor and the products of the p53 gene (the wild and mutant forms) and the oncogene c-myc, by means of immunochemical techniques (Western blot, ELISA, and quantification of immunostaining in histological sections). In normal prostate, IFN-gamma and its two receptors were expressed in the basal cells of the epithelium and some stromal cells. In BPH specimens, immunostaining of basal epithelial cells was significantly increased for IFN-gamma and its a receptor, whereas stromal cell immunostaining was significantly increased for IFN-gamma and its b receptor. In addition, columnar epithelial cells immunostained for IFNbeta-Rbeta. PC specimens differed from BPH specimens in the significantly increased immunostaining of epithelial cells for IFN-gamma and its two receptors, and the immunostaining of columnar epithelial cells for IFN-gamma-Ralpha. Immunodetection of wild-p53 was weak and limited to some stromal cells in the three types of specimens. Immunostainings for both mutant-p53 and c-myc were negative in normal prostate, and positive in the epithelium and stromal cells of both BPH and PC specimens. Immunostaining intensity in PC was significantly higher than in BPH. These observations suggest that the expression of both mutant-p53 and c-myc, together with other factors, might be involved in the development of prostatic hyperplasia and neoplasia, while the increased expression of IFN-gamma and its receptors could be regarded as an attempt, although insufficient, to inhibit the uncontrolled cell proliferation.

Distinct roles of oncostatin M and leukemia inhibitory factor in the development of primordial germ cells and sertoli cells in mice

Leukemia inhibitory factor (LIF) stimulates the growth of primordial germ cells (PGCs) in mouse embryo. However, as neither mice lacking LIF nor mice lacking the LIF receptor show defects in PGC growth, an alternate cytokine for PGC growth has been postulated. We investigated the role of mouse oncostatin M (mOSM), which is structurally and functionally related to LIF, in germ cell development. While LIF enhanced the survival of migratory as well as postmigratory PGCs, mOSM acted only on the postmigratory PGCs. Consistent with its biological activity, mOSM was found to be expressed in developing gonads. In the male, Sertoli cells in neonatal testis express mOSM; however, its expression is downregulated in adult testes. Moreover, mOSM enhanced the proliferation of Sertoli cells derived from neonatal testes in vitro more than human OSM or LIF. In contrast, postnatal ovaries do not express mOSM. These results indicate that mOSM is a stage- and sex-specific autocrine growth factor for Sertoli cells.

Intermediate filaments in the Sertoli cells of the ageing human testis

The presence and distribution of intermediate filaments (vimentin, keratin, desmin) was studied in the Sertoli cells of elderly men by means of quantitative immunohistochemical methods. Sertoli cells from young men showed moderate immunogold labelling to vimentin throughout the entire cytoplasm between the cell organelles in tubules showing complete spermatogenesis. Immunogold particles were more numerous in the perinuclear cytoplasm and beneath the plasma membrane in all its faces. The testes from elderly men showed different tubule types; some showed complete spermatogenesis and a normal lamina propria, while others had spermatogenic arrest at different levels (spermatids, spermatocytes, spermatogonia). The immunohistochemical reaction to vimentin in the Sertoli cells of tubules with complete spermatogenesis (type a) was similar to that in the cells of young men. In the Sertoli cells of severely damaged tubules (type b) the immunohistochemical reaction was more intense and immunogold particles extended in similar proportions throughout the whole cytoplasm. When immunolabelling intensity was compared between the three groups of tubules, by counting the number of immunogold particles per square micrometre of cytoplasm, it was found to be significantly higher (P < or = 0.05) in type b tubules of elderly men than either in tubules of young men or in type a tubules of elderly men. Since the average cell surface of Sertoli cells was similar in all tubule types, these data suggest that an actual vimentin increase occurs in Sertoli cells of germ-cell-depleted tubules. Sertoli cell immunogold labelling to keratin was found neither in young men nor in type a tubules of ageing men, whereas a positive immunohistochemical reaction was observed in the Sertoli cells of type b tubules of elderly men. Immunogold particles were localized mainly in the perinuclear cytoplasm, and beneath the lateral and basal cell surfaces. The observation of vimentin increase and keratin re-expression in ageing Sertoli cells only in germ-cell-depleted tubules suggests that the changes in intermediate filaments are related to the local factors associated with completion of spermatogenesis, causing functional changes in Sertoli cells.

Immunomagnetic isolation of fetal rat gonocytes

PROBLEM

An efficient method to obtain highly enriched populations of viable gonocytes from rat embryos at Day 18 and Day 20 postcoitum (pc) is described.

METHOD

Single-cell suspensions with high cell yield were obtained by a collagenase/ trypsin digestion of the decapsulated testis. The gonocytes were purified by a direct immunoseparation technique, using magnetizable beads coated with rat anti-mouse immunoglobulin M (IgM) and a monoclonal antibody 4B6.3E10, which specifically reacted with a differentiation antigen on the fetal germ cells.

RESULTS

Populations of 8.3 +/- 2.7 (x10(3); 18 days pc) or 1.2 +/- 0.25 (x10(4); 20 days pc) viable gonocytes per testis with purities of 91 +/- 6.5% and 92 +/- 4.3%, respectively, as determined by Nomarski microscopy were obtained.

CONCLUSION

The cells were successfully used for culture studies and as starting material for the investigation of gene expression.

Ontogeny and localization of an oncostatin M-like protein in the rat testis: its possible role at the start of spermatogenesis

Oncostatin M (OSM), a member of the interleukin 6 family of cytokines, was found to be highly expressed in the late fetal and early neonatal rat testis, as well as in the maturing and adult testis. Two different forms of OSM were observed, one of M(r) 22,000 and the other of M(r) 36,000. In the prepubertal rat testis [19 days post coitum, 8 days post partum (dpp), and 15 dpp], the form with the higher molecular weight prevailed, whereas in the maturing testis (30 dpp, 45 dpp, and 12 weeks post partum), a shift toward the lower molecular weight form was observed, as well as a decrease in its relative amount. By immunohistochemistry on testicular sections, OSM-specific immunostaining was observed in the interstitial tissue at every age studied. In contrast, OSM immunoreaction was localized in the Sertoli cells exclusively around the start of spermatogenesis, being strongest at 3 dpp. In vitro studies revealed that neonatal Sertoli cells produce OSM. The possible role of OSM at the start of spermatogenesis was investigated by using a coculture of Sertoli cells and gonocytes isolated from newborn rats. OSM significantly increased the survival of both Sertoli cells and gonocytes in a dose-dependent manner. The proliferative activity of the Sertoli cells was not affected by OSM, whereas that of gonocytes was increased by almost 60% after 6 days of culture. Comparison of the effect of OSM on these cocultures with other members of the interleukin 6 family of cytokines demonstrated that this factor is more potent than leukemia inhibitory factor or ciliary neurotrophic factor. On the basis of these findings, it can be concluded that OSM is present in the rat testis, and it is likely to play an important role at the start of spermatogenesis.

Lectin histochemistry in the human epididymis

A histochemical study using lectins to identify glycoconjugates present in the efferent ducts and ductus epididymidis of men without testicular or related disease was carried out. The lectins used and the oligosaccharide residues linked were: wheat germ agglutinin (WGA) for beta-N-acetylglucosamine and sialic acid, concanavalin A (ConA) for alpha-mannose, Ulex europaeus agglutinin (UEA-I) for alpha-fucose, Dolichos biflorus agglutinin (DBA) for alpha-N-acetylgalactosamine, soy bean agglutinin (SBA) for beta-N-acetylgalactosamine, and peanut agglutinin (PNA) for beta-galactose. The lectin-binding pattern in the human epididymis presents similarities and differences to those observed in other mammals which also showed differences between species. The present results revealed that regional differences along the human ductus epididymidis were less pronounced than those reported in other mammals. The epithelial cells in the efferent ducts reacted positively to WGA. All along the length of the ductus epididymidis, the principal cells and the luminal content showed staining affinity for WGA and ConA. The epididymal principal cells and luminal content also reacted positively to DBA for alpha-N-acetylgalactosamine but only in the cauda epididymidis. A positive reaction to UEA-I was observed only in the luminal content of the cauda epididymidis. This finding suggests that changes in the oligosaccharide chains of secretions leading to a positive UEA-I reaction occur in the cauda epididymidis. The epididymal principal cells showed positive reactions to SBA and PNA over the apical microvilli but not in the cytoplasm. The reaction was observed in the caput and corpus epididymidis but not in the cauda. Positive reactions to SBA and PNA were also detected in the epididymal fluid and in the cytoplasm of mitochondria-rich cells (a minor population of epididymal epithelial cells). These cells also reacted to other lectins such as WGA, ConA and DBA, which were also detected in the principal cells.