Akt2 deficiency protects from acute lung injury via alternative macrophage activation and miR-146a induction in mice.

Acute respiratory distress syndrome (ARDS) is a major cause of respiratory failure, with limited effective treatments available. Alveolar macrophages participate in the pathogenesis of ARDS. To investigate the role of macrophage activation in aseptic lung injury and identify molecular mediators with therapeutic potential, lung injury was induced in wild-type (WT) and Akt2(-/-) mice by hydrochloric acid aspiration. Acid-induced lung injury in WT mice was characterized by decreased lung compliance and increased protein and cytokine concentration in bronchoalveolar lavage fluid. Alveolar macrophages acquired a classical activation (M1) phenotype. Acid-induced lung injury was less severe in Akt2(-/-) mice compared with WT mice. Alveolar macrophages from acid-injured Akt2(-/-) mice demonstrated the alternative activation phenotype (M2). Although M2 polarization suppressed aseptic lung injury, it resulted in increased lung bacterial load when Akt2(-/-) mice were infected with Pseudomonas aeruginosa. miR-146a, an anti-inflammatory microRNA targeting TLR4 signaling, was induced during the late phase of lung injury in WT mice, whereas it was increased early in Akt2(-/-) mice. Indeed, miR-146a overexpression in WT macrophages suppressed LPS-induced inducible NO synthase (iNOS) and promoted M2 polarization, whereas miR-146a inhibition in Akt2(-/-) macrophages restored iNOS expression. Furthermore, miR-146a delivery or Akt2 silencing in WT mice exposed to acid resulted in suppression of iNOS in alveolar macrophages. In conclusion, Akt2 suppression and miR-146a induction promote the M2 macrophage phenotype, resulting in amelioration of acid-induced lung injury. In vivo modulation of macrophage phenotype through Akt2 or miR-146a could provide a potential therapeutic approach for aseptic ARDS; however, it may be deleterious in septic ARDS because of impaired bacterial clearance.

TPL2 kinase is a suppressor of lung carcinogenesis.

Lung cancer is a heterogeneous disease at both clinical and molecular levels, posing conceptual and practical bottlenecks in defining key pathways affecting its initiation and progression. Molecules with a central role in lung carcinogenesis are likely to be targeted by multiple deregulated pathways and may have prognostic, predictive, and/or therapeutic value. Here, we report that Tumor Progression Locus 2 (TPL2), a kinase implicated in the regulation of innate and adaptive immune responses, fulfils a role as a suppressor of lung carcinogenesis and is subject to diverse genetic and epigenetic aberrations in lung cancer patients. We show that allelic imbalance at the TPL2 locus, up-regulation of microRNA-370, which targets TPL2 transcripts, and activated RAS (rat sarcoma) signaling may result in down-regulation of TPL2 expression. Low TPL2 levels correlate with reduced lung cancer patient survival and accelerated onset and multiplicity of urethane-induced lung tumors in mice. Mechanistically, TPL2 was found to antagonize oncogene-induced cell transformation and survival through a pathway involving p53 downstream of cJun N-terminal kinase (JNK) and be required for optimal p53 response to genotoxic stress. These results identify multiple oncogenic pathways leading to TPL2 deregulation and highlight its major tumor-suppressing function in the lung.

Akt1 and Akt2 protein kinases differentially contribute to macrophage polarization.

Activated macrophages are described as classically activated or M1 type and alternatively activated or M2 type, depending on their response to proinflammatory stimuli and the expression of genetic markers including iNOS, arginase1, Ym1, and Fizz1. Here we report that Akt kinases differentially contribute to macrophage polarization, with Akt1 ablation giving rise to an M1 and Akt2 ablation resulting in an M2 phenotype. Accordingly, Akt2(-/-) mice were more resistant to LPS-induced endotoxin shock and to dextran sulfate sodium (DSS)-induced colitis than wild-type mice, whereas Akt1(-/-) mice were more sensitive. Cell depletion and reconstitution experiments in a DSS-induced colitis model confirmed that the effect was macrophage-dependent. Gene-silencing studies showed that the M2 phenotype of Akt2(-/-) macrophages was cell autonomous. The microRNA miR-155, whose expression was repressed in naive and in LPS-stimulated Akt2(-/-) macrophages, and its target C/EBPß appear to play a key role in this process. C/EBPß, a hallmark of M2 macrophages that regulates Arg1, was up-regulated upon Akt2 ablation or silencing. Overexpression or silencing of miR-155 confirmed its central role in Akt isoform-dependent M1/M2 polarization of macrophages.

APRIL binding to BCMA activates a JNK2-FOXO3-GADD45 pathway and induces a G2/M cell growth arrest in liver cells.

The TNF superfamily ligands APRIL and BAFF bind with different affinity to two receptors, BCMA and TACI, and induce cell survival and/or proliferation, whereas BAFF also binds specifically to BAFFR. These molecules were considered specific for the immune system. Recently, however, they were also found in epithelial and mesenchymal noncancerous and cancerous tissues and cell lines. In this article, we report that hepatocellular carcinoma (HCC) cell lines HepG2 and Hep3B and HCC specimens express APRIL and BAFF and their receptors BCMA and BAFFR, but not TACI; APRIL/BCMA is enhanced in HCC, compared with normal liver tissue. In contrast to previous reports, APRIL binding to BCMA decreases cell proliferation by inducing G(2)/M cell cycle arrest, whereas BAFF has no effect on cell growth. HCC cells therefore represent a rare system in which these two ligands (APRIL and BAFF) exert a differential effect and may serve as a model for specific APRIL/BCMA actions. We show that the effect of APRIL is mediated via BCMA, which does not activate the classical NF-κB pathway, whereas it induces a novel signaling pathway, which involves JNK2 phosphorylation, FOXO3A activation, and GADD45 transcription. In addition, JNK2 mediates the phosphorylation of Akt, which is activated but does not participate in the antiproliferative effect of APRIL. Furthermore, transcriptome analysis revealed that APRIL modifies genes specifically related to cell cycle modulation, including MCM2/4/5/6, CDC6, PCNA, and POLE2. Our data, therefore, identify a novel APRIL/BCMA signaling pathway in HCC and suggest that APRIL could have a pleiotropic role in tumor biology.

LKB1 Loss Correlates with STING Loss and, in Cooperation with ß-Catenin Membranous Loss, Indicates Poor Prognosis in Patients with Operable Non-Small Cell Lung Cancer.

To investigate the incidence and prognostically significant correlations and cooperations of LKB1 loss of expression in non-small cell lung cancer (NSCLC), surgical specimens from 188 metastatic and 60 non-metastatic operable stage I-IIIA NSCLC patients were analyzed to evaluate their expression of LKB1 and pAMPK proteins in relation to various processes. The investigated factors included antitumor immunity response regulators STING and PD-L1; pro-angiogenic, EMT and cell cycle targets, as well as metastasis-related (VEGFC, PDGFRα, PDGFRß, p53, p16, Cyclin D1, ZEB1, CD24) targets; and cell adhesion (ß-catenin) molecules. The protein expression levels were evaluated via immunohistochemistry; the RNA levels of LKB1 and NEDD9 were evaluated via PCR, while KRAS exon 2 and BRAFV600E mutations were evaluated by Sanger sequencing. Overall, loss of LKB1 protein expression was observed in 21% (51/248) patients and correlated significantly with histotype (p < 0.001), KRAS mutations (p < 0.001), KC status (concomitant KRAS mutation and p16 downregulation) (p < 0.001), STING loss (p < 0.001), and high CD24 expression (p < 0.001). STING loss also correlated significantly with loss of LKB1 expression in the metastatic setting both overall (p = 0.014) and in lung adenocarcinomas (LUACs) (p = 0.005). Additionally, LKB1 loss correlated significantly with a lack of or low ß-catenin membranous expression exclusively in LUACs, both independently of the metastatic status (p = 0.019) and in the metastatic setting (p = 0.007). Patients with tumors yielding LKB1 loss and concomitant nonexistent or low ß-catenin membrane expression experienced significantly inferior median overall survival of 20.50 vs. 52.99 months; p < 0.001 as well as significantly greater risk of death (HR: 3.32, 95% c.i.: 1.71-6.43; p <0.001). Our findings underscore the impact of the synergy of LKB1 with STING and ß-catenin in NSCLC, in prognosis.

Expression of miRNAs involved in angiogenesis, tumor cell proliferation, tumor suppressor inhibition, epithelial-mesenchymal transition and activation of metastasis in bladder cancer.

PURPOSE: miRNAs are noncoding RNAs that posttranscriptionally regulate gene expression. Altered expression and function have been observed in bladder cancer. We analyzed the expression profile of a group of miRNAs involved in bladder cancer angiogenesis, tumor cell proliferation, tumor suppressor inhibition, epithelial-mesenchymal transition and metastasis activation. Prognostic and diagnostic value, and validated targets were further examined. MATERIALS AND METHODS: Using quantitative real-time polymerase chain reaction 77 bladder cancer cases and 77 matched tumor associated normal samples were investigated to determine the expression of miR-10b, 19a, 19b, 21, 126, 145, 205, 210, 221, 296-5p and 378. The relationship between miRNA expression, patient survival and tumor pathological features was also examined. RESULTS: miR-10b, 19a, 126, 145, 221, 296-5p and 378 were significantly down-regulated in bladder cancer compared to adjacent normal urothelium. miR-145 was the most down-regulated microRNA of this group. miR-19b, 21, 205 and 210 showed no significant difference between the 2 tissue types. High miR-21 expression correlated with worse overall patient survival (p = 0.0099). Multivariate analysis revealed that miR-21, 210 and 378 may serve as independent prognostic factors for overall patient survival (p = 0.005, 0.033 and 0.012, respectively). miR-21 and 378 may serve as independent prognostic factors for recurrence (p = 0.030 and 0.031, respectively). miR-145, 221, 296-5p and 378 showed the best combined ROC curves for specificity and sensitivity. miRWalk analysis was used to identify validated miRNA target genes. Further Gene Ontology enrichment revealed the main classes of biological functions of these validated targets. CONCLUSIONS: Most miRNAs analyzed are down-regulated in bladder cancer. They may serve as candidate biomarkers for diagnostic and prognostic purposes in the future.

Role of platelet-derived growth factor-AB in tumour growth and angiogenesis in relation with other angiogenic cytokines in multiple myeloma.

Angiogenesis is a complex process essential for the growth, invasion, and metastasis of various malignant tumours, including multiple myeloma (MM). Various angiogenic cytokines have been implicated in the angiogenic process. Among them, platelet-derived growth factor-AB (PDGF-AB) has been reported to be a potent stimulator of angiogenesis in many solid tumours and haematological malignancies, including MM. The aim of the study was to investigate the relationship between PDGF-AB, microvascular density (MVD), and various angiogenic cytokines, such as basic fibroblast growth factor (b-FGF), angiogenin (ANG), and interleukin-6 (IL-6), in MM patients. Forty-seven MM patients before treatment, 22 of whom were in plateau phase, were studied. We determined the serum levels of the aforementioned cytokines and MVD in bone marrow biopsies before and after treatment. Mean serum values of PDGF-AB, b-FGF, ANG, and MVD were significantly higher in patients compared with controls and with increasing disease stage. Significant positive correlations were observed between serum PDGF-AB, ANG, and IL-6 levels and MVD. Furthermore, we found significant positive correlations between PDGF-AB and b-FGF, IL-6, ANG, and ß2 microglobulin. We also found that patients with high MVD had statistically significantly higher serum levels of PDGF-AB when a median MVD value of 7.7 was used as the cutoff point. Furthermore, a significant difference was found in serum levels of PDGF-AB between pre- and post-treatment patients. Finally, survival time was significantly higher in the low MVD group versus the high MVD group (76 vs 51 months). Our results showed that there is a strong positive correlation between PDGF-AB and the studied angiogenic cytokines and MVD. It seems that PDGF-AB plays a role in the complex network of cytokines inducing bone marrow neovascularization in patients with MM.

KIT receptor activation by autocrine and paracrine stem cell factor stimulates growth of merkel cell carcinoma in vitro.

The co-expression of KIT receptor and its ligand stem cell factor (SCF) has been reported in biopsy specimens of Merkel cell carcinoma (MCC). However, the functional role of SCF/KIT in the pathogenesis of this aggressive tumor has not been elucidated. The present study reports expression and effects of SCF and KIT in the Merkel cell carcinoma cell line MCC-1 in vitro. SCF and KIT were endogenously co-expressed in MCC-1 cells. Exogenous soluble SCF modulated KIT receptor mRNA and protein expression, stimulated growth of MCC-1 cells, upregulated endogenous activation of KIT, AKT, and of extracellular signal-regulated kinase (ERK) 1/2 signaling pathway. On the contrary, an inhibitory antibody that neutralized the KIT ligand binding site, reduced growth of MCC-1 cells, as did high doses of the KIT kinase inhibitors imatinib and nilotinib. Also, inhibitors of KIT downstream effectors, U0126 that blocks MEK1/2 as well as wortmannin and LY294002 that inhibit phosphatidylinositol 3-kinase-dependent AKT phosphorylation, inhibited the proliferation of MCC-1 cells. These data support the hypothesis that KIT is activatable by paracrine or autocrine tumor cell-derived SCF and stimulates growth of Merkel cell carcinoma in vitro. Blockade of KIT and the downstream signaling cascade at various levels results in inhibition of Merkel cell carcinoma growth in vitro, suggesting targets for therapy of this cancer.

Novel oligomeric proanthocyanidin derivatives interact with membrane androgen sites and induce regression of hormone-independent prostate cancer.

Prostate cancer is the most common malignancy among men in Western societies, and current therapeutic approaches are evolving to manage growth, recurrence, and mortality neoplasia. Membrane androgen receptors (mARs) have been characterized in human prostate cancer, being preferentially expressed in tumor rather than benign gland areas. Furthermore, mAR agonists (protein-conjugated testosterone) decrease in vitro prostate cancer cell growth and induce apoptosis, whereas in vivo they regress growth of tumor xenografts alone or in combination with taxane drugs. In this respect, targeting mARs might be a novel therapeutic approach in prostate cancer. In our search for new small-molecule ligands of mAR, we report that flavanol dimers B1-B4 (oligomeric procyanidins) decrease in vitro growth of the androgen-sensitive (LnCaP) and androgen-resistant (DU145) human prostate cancer cell lines in the following order: B3 = B4 > B2 ≫ B1 (LnCaP) and B2 ≫ B3 = B4 ≫ B1 (DU145). Some of these analogs were previously shown to trigger signaling cascades similar to testosterone-bovine serum albumin (BSA) conjugate. Galloylation does not confer an additional advantage; however, oleylation increases the dimers' antiproliferative potency by a factor of 100. In addition, we report that B2, oleylated or not, displaces testosterone from mARs with an IC(50) value at the nanomolar range and induces DU145 tumor xenograft regression by 50% (testosterone-BSA 40%). In this respect, oleylated B2 is a potent small-molecule agonist of mAR and could be a novel therapeutic agent for advanced prostate cancer, especially when taking into account the absence of androgenic actions and (liver) toxicity.

Death ligand TRAIL, secreted by CD1a+ and CD14+ cells in blister fluids, is involved in killing keratinocytes in toxic epidermal necrolysis.

Toxic epidermal necrolysis (TEN) is characterized by an acute detachment and destruction of keratinocytes, affecting large areas of the skin. It is often related to adverse drug reactions. Previous studies have shown that effector CD8+ T cells, which accumulate in the blister fluid, are functionally cytotoxic and act through a classical perforin/granzyme B pathway. It has recently been shown that these cytotoxic T cells also secrete granulysin peptide, which is lethal to keratinocytes. These cytotoxic T cells exert their killer activity against autologous keratinocytes in the presence of the drug. However, they are unlikely to be the only effectors of TEN. We therefore searched for soluble death factors in the blister fluids that might kill keratinocytes. We found that the amounts of interferon-γ, TRAIL and TNF-α proteins were significantly greater in TEN blister fluids than in all controls (normal sera, TEN sera, burns and Eosinophilic pustular folliculitis blister fluids) and TNF-like weak inducer of apoptosis (TWEAK) amounts are also greater in all controls except burns. We showed that these proteins acted in synergy to induce the death of keratinocytes in vitro. We also found that TRAIL and TWEAK were secreted by CD1a+ and CD14+ cells present in the blister fluids. Thus, in addition to MHC class I-restricted cytotoxic T lymphocytes (CTLs), which lyse keratinocytes, ligands secreted by non-lymphoid cells capable of inducing keratinocyte death in an MHC class I-independent manner, also seem to be present in the blister fluids of patients with TEN.

Adipocytes as immune cells: differential expression of TWEAK, BAFF, and APRIL and their receptors (Fn14, BAFF-R, TACI, and BCMA) at different stages of normal and pathological adipose tissue development.

Adipose tissue represents a rich source of multipotent stem cells. Mesenchymal cells, isolated from this source, can differentiate to other cell types in vitro and therefore can be used for a number of regenerative therapies. Our view of adipose tissue has recently changed, establishing adipocytes as new members of the immune system, as they produce a number of proinflammatory cytokines (such as IL-6 and TNFalpha and chemokines, in addition to adipokines (leptin, adiponectin, resistin) and molecules associated with the innate immune system. In this paper, we report the differential expression of TNF-superfamily members B cell activating factor of the TNF Family (BAFF), a proliferation inducing ligand (APRIL), and TNF-like weak inducer of apoptosis (TWEAK) in immature-appearing and mature adipocytes and in benign and malignant adipose tissue-derived tumors. These ligands act through their cognitive receptors, BAFF receptor, transmembrane activator and calcium signal-modulating cyclophilic ligand (TACI), B cell maturation Ag (BCMA), and fibroblast growth factor-inducible 14 (Fn14), which are also expressed in these cells. We further report the existence of functional BCMA, TACI, and Fn14 receptors and their ligands BAFF, APRIL, and TWEAK on adipose tissue-derived mesenchymal cells, their interaction modifying the rate of adipogenesis. Our data integrate BAFF, APRIL, and TWEAK and their receptors BCMA, TACI, and Fn14 as novel potential mediators of adipogenesis, in addition to their specific role in immunity, and define immature and mature adipocytes as source of immune mediators.

The impact of stress on tumor growth: peripheral CRF mediates tumor-promoting effects of stress.

INTRODUCTION: Stress has been shown to be a tumor promoting factor. Both clinical and laboratory studies have shown that chronic stress is associated with tumor growth in several types of cancer. Corticotropin Releasing Factor (CRF) is the major hypothalamic mediator of stress, but is also expressed in peripheral tissues. Earlier studies have shown that peripheral CRF affects breast cancer cell proliferation and motility. The aim of the present study was to assess the significance of peripheral CRF on tumor growth as a mediator of the response to stress in vivo. METHODS: For this purpose we used the 4T1 breast cancer cell line in cell culture and in vivo. Cells were treated with CRF in culture and gene specific arrays were performed to identify genes directly affected by CRF and involved in breast cancer cell growth. To assess the impact of peripheral CRF as a stress mediator in tumor growth, Balb/c mice were orthotopically injected with 4T1 cells in the mammary fat pad to induce breast tumors. Mice were subjected to repetitive immobilization stress as a model of chronic stress. To inhibit the action of CRF, the CRF antagonist antalarmin was injected intraperitoneally. Breast tissue samples were histologically analyzed and assessed for neoangiogenesis. RESULTS: Array analysis revealed among other genes that CRF induced the expression of SMAD2 and ß-catenin, genes involved in breast cancer cell proliferation and cytoskeletal changes associated with metastasis. Cell transfection and luciferase assays confirmed the role of CRF in WNT- ß-catenin signaling. CRF induced 4T1 cell proliferation and augmented the TGF-ß action on proliferation confirming its impact on TGFß/SMAD2 signaling. In addition, CRF promoted actin reorganization and cell migration, suggesting a direct tumor-promoting action. Chronic stress augmented tumor growth in 4T1 breast tumor bearing mice and peripheral administration of the CRF antagonist antalarmin suppressed this effect. Moreover, antalarmin suppressed neoangiogenesis in 4T1 tumors in vivo. CONCLUSION: This is the first report demonstrating that peripheral CRF, at least in part, mediates the tumor-promoting effects of stress and implicates CRF in SMAD2 and ß-catenin expression.

PTEN-loss and nuclear atypia of EIN in endometrial biopsies can predict the existence of a concurrent endometrial carcinoma.

AIM: The objective of the present study was to evaluate whether nuclear atypia or PTEN-loss in endometrial intraepithelial neoplasia (EIN), could help to predict in endometrial curettage material, the prevalence of concurrent carcinoma in hysterectomy specimens. MATERIALS AND METHODS: This retrospective single-institution study included women who were diagnosed with endometrial hyperplasia (simple or complex) and underwent hysterectomy within 12weeks from the initial diagnosis without interval treatment. All endometrial curettage slides were reviewed by three experienced pathologists and only cases that fulfilled the criteria of EIN were used for further analysis. For each case, the nuclear atypia and the immunohistochemically detected expression of PTEN were evaluated. The hysterectomy slides were also reviewed and the findings were used in the subsequent analysis. RESULTS: Out of 83 cases that were enrolled in the study, 33 (39.76%), had a concurrent endometrial carcinoma. Nuclear atypia in EIN cases with a final histology of endometrial cancer was found in 31 out of 33 cases (93.94%) but only in 27 out of 50 benign cases (54%). There was no PTEN-loss in 8 out of 33 EIN cases (24.24%) that proved to be cancer and 22 out of 50 EIN cases (44%) that proved to be benign. Either atypia or PTEN-loss or both were found in 33/33 (100%) cancer cases and in 39/50 (78%) benign cases; this difference was statistically significant (Fisher exact test, p < 0.05). CONCLUSION: PTEN-loss, as an independent variable, was not found to be a predictor of endometrial cancer in the final histology. However, biopsies presented with EIN, featuring nuclear atypia and recognized as PTEN-null are more likely to be finally diagnosed with endometrial cancer.

A pre-tailored panel of antibodies in the study of cervical mesonephric remnants.

AIMS: To investigate the immunohistochemical profile of cervical mesonephric remnants. METHODS AND RESULTS: Cases of mesonephric remnants, microglandular hyperplasia, tunnel clusters, tuboendometrioid metaplasia and cervical adenocarcinomas were immunohistochemically stained with Ki-67, CD10, bcl2 and p16. All 26 cases of mesonephric remnants were strongly positive for bcl2 and weakly to moderately positive for p16. CD10 was positive in 19 cases. Seven cases were negative and 19 weakly positive for Ki-67. All 10 cases of tuboendometrioid metaplasia showed high positivity for bcl2. Two cases were negative for p16; seven cases presented low and one case moderate positivity. Five cases were negative for CD10, while in five the staining was low. Six cases of tuboendometrioid metaplasia were negative for Ki-67, while four showed low staining. Tunnel clusters were negative for all antibodies, except one, which showed focal positivity for Ki-67 and p16. All cases of microglandular hyperplasia were negative for bcl2, p16 and CD10 and only 5/12 showed focal positivity for Ki-67. All adenocarcinomas were negative for bcl2 and CD10, and highly positive for p16 and Ki-67. CONCLUSIONS: bcl2 is more constantly and strongly expressed in mesonephric remnants than CD10. p16 is weakly to moderately positive, while Ki-67 is negative to weakly positive.

The TNFSF Members APRIL and BAFF and Their Receptors TACI, BCMA, and BAFFR in Oncology, With a Special Focus in Breast Cancer.

Tumor necrosis factor (TNF) superfamily consists of 19 ligands and 29 receptors and is related to multiple cellular events from proliferation and differentiation to apoptosis and tumor reduction. In this review, we overview the whole system, and we focus on A proliferation-inducing ligand (APRIL, TNFSF13) and B cell-activating factor (BAFF, TNFSF13B) and their receptors transmembrane activator and Ca2+ modulator (CAML) interactor (TACI, TNFRSF13B), B cell maturation antigen (BCMA, TNFRSF17), and BAFF receptor (BAFFR, TNFRSF13C). We explore their role in cancer and novel biological therapies introduced for multiple myeloma and further focus on breast cancer, in which the modulation of this system seems to be of potential interest, as a novel therapeutic target. Finally, we discuss some precautions which should be taken into consideration, while targeting the APRIL-BAFF system.

Co-expression of KIT receptor and its ligand stem cell factor in Merkel cell carcinoma.

BACKGROUND/AIMS: KIT receptor has been implicated in the pathogenesis of cancer, either by mutation or autocrine activation. Merkel cell carcinoma (MCC) is a rare KIT-positive cutaneous tumor. We investigated the co-expression of KIT and its ligand stem cell factor (SCF) in MCC. METHODS: Sixteen specimens from 13 MCC patients of various tumor stages were examined by immunohistochemistry for SCF, KIT, Ki67/MIB-1 and cleaved caspase 3 expression, and for apoptosis by TUNEL. RESULTS: KIT was expressed in 13 of 16 tumors, and SCF in 15 of 16 specimens. Co-expression of KIT and SCF was detected in 12 of 16 tumors. KIT and SCF immunoreactivity scores were independent of tumor stage. Ki67/MIB-1 proliferation rates were high, whereas apoptosis rates were low, and did not depend on KIT or SCF expression. CONCLUSION: Co-expression of KIT and SCF in a high percentage of MCC tumors hints to an autocrine mechanism. KIT and SCF expression in primary tumors and in metastases suggests an early event in Merkel cell transformation.

Histological expression of angiogenic factors: VEGF, PDGFRalpha, and HIF-1alpha in Hodgkin lymphoma.

Angiogenesis is a prerequisite for solid tumor growth, but there is relatively limited data regarding Hodgkin lymphoma. The purpose of this study was to examine the immunohistochemical expression of angiogenic and proliferation markers in Hodgkin biopsies in relation to clinical parameters. Immunostaining was performed on 65 Hodgkin biopsies with vascular endothelial growth factor (VEGF), hypoxia inducible factor-1 alpha (HIF-1alpha), platelet-derived growth factor receptor alpha (PDGFRalpha), Ki-67, and p53. Microvessel density (MVD) was determined by CD31 staining. In all cases, neoplastic cells and reactive background cells were evaluated. The neoplastic population expressed VEGF in 48% of the cases, HIF-1alpha in 54% of the cases, and PDGFRalpha in 95% of the cases. Both Ki-67 and p53 were positive in neoplastic cells in over 60% of the cases. The MVD had a median of 2.6/0.0625mm(2) which was not different from normal lymph nodes. VEGF in the non-neoplastic compartment showed increased staining in Ann Arbor stage I-II versus III-IV. In conclusion, VEGF, HIF-1alpha, and predominantly PDGFRalpha are expressed in neoplastic cells in the majority of Hodgkin lymphomas. As microvessel formation is not increased in Hodgkin, additional functions of these angiogenic molecules should be investigated.

Membrane androgen receptors (OXER1, GPRC6A AND ZIP9) in prostate and breast cancer: A comparative study of their expression.

Accumulating evidence during the last decades revealed that androgens exert membrane-initiated actions leading to the modulation of significant cellular processes, important for cancer cell growth and metastasis (including prostate and breast), that involve signaling via specific kinases. Collectively, many nonclassical, cell surface-initiated androgen actions are mediated by novel membrane androgen receptors (mARs), unrelated to nuclear androgen receptors. Recently, our group identified the G protein coupled oxo-eicosanoid receptor 1 (OXER1) (a receptor of the arachidonic acid metabolite, 5-oxoeicosatetraenoic acid, 5-oxoETE) as a novel mAR involved in the rapid effects of androgens. However, two other membrane proteins, G protein-coupled receptor family C group 6 member A (GPRC6A) and zinc transporter member 9 (ZIP9) have also been portrayed as mARs, related to the extranuclear action of androgens. In the present work, we present a comparative study of in silico pharmacology, gene expression and immunocytochemical data of the three receptors in various prostate and breast cancer cell lines. Furthermore, we analyzed the immunohistochemical expression of these receptors in human tumor and non-tumoral specimens and provide a pattern of expression and intracellular distribution.

Estrogen receptor-alpha isoforms are the main estrogen receptors expressed in non-small cell lung carcinoma.

The expression profile of estrogen receptors (ER) in Non-Small Cell Lung Carcinoma (NSCLC) remains contradictory. Here we investigated protein and transcriptome expression of ERα wild type and variants. Tissue Micro-Arrays of 200 cases of NSCLC (paired tumor/non-tumor) were assayed by immunohistochemistry using a panel of ERα antibodies targeting different epitopes (HC20, 6F11, 1D5, ERα36 and ERα17p). ERß epitopes were also examined for comparison. In parallel we conducted a probe-set mapping (Affymetrix HGU133 plus 2 chip) meta-analysis of 12 NSCLC tumor public transcriptomic studies (1418 cases) and 39 NSCLC cell lines. Finally, we have investigated early transcriptional effects of 17ß-estradiol, 17ß-estradiol-BSA, tamoxifen and their combination in two NSCLC cell lines (A549, H520). ERα transcript and protein detection in NSCLC specimens and cell lines suggests that extranuclear ERα variants, like ERα36, prevail, while wild-type ERα66 is minimally expressed. In non-tumor lung, the wild-type ERα66 is quasi-absent. The combined evaluation of ERα isoform staining intensity and subcellular localization with sex, can discriminate NSCLC subtypes and normal lung. Overall ERα transcription decreases in NSCLC. ERα expression is sex-related in non-tumor tissue, but in NSCLC it is exclusively correlating with tumor histologic subtype. ERα isoform protein expression is higher than ERß. ERα isoforms are functional and display specific early transcriptional effects following steroid treatment. In conclusion, our data show a wide extranuclear ERα-variant expression in normal lung and NSCLC that is not reported by routine pathology ER evaluation criteria, limited in the nuclear wild type receptor.