Metabolic Footprinting of a Clear Cell Renal Cell Carcinoma in Vitro Model for Human Kidney Cancer Detection.

A protocol for harvesting and extracting extracellular metabolites from an in vitro model of human renal cell lines was developed to profile the exometabolome by means of a discovery-based metabolomics approach using ultraperformance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry. Metabolic footprints provided by conditioned media (CM) samples ( n = 66) of two clear cell Renal Cell Carcinoma (ccRCC) cell lines with different genetic backgrounds and a nontumor renal cell line, were compared with the human serum metabolic profile of a pilot cohort ( n = 10) comprised of stage IV ccRCC patients and healthy individuals. Using a cross-validated orthogonal projection to latent structures-discriminant analysis model, a panel of 21 discriminant features selected by iterative multivariate classification, allowed differentiating control from tumor cell lines with 100% specificity, sensitivity, and accuracy. Isoleucine/leucine, phenylalanine, N-lactoyl-leucine, and N-acetyl-phenylalanine, and cysteinegluthatione disulfide (CYSSG) were identified by chemical standards, and hydroxyprolyl-valine was identified with MS and MS/MS experiments. A subset of 9 discriminant features, including the identified metabolites except for CYSSG, produced a fingerprint of classification value that enabled discerning ccRCC patients from healthy individuals. To our knowledge, this is the first time that N-lactoyl-leucine is associated with ccRCC. Results from this study provide a proof of concept that CM can be used as a serum proxy to obtain disease-related metabolic signatures.

Bromopyrrole alkaloids isolated from the Patagonian bryozoan Aspidostoma giganteum.

Nine new bromopyrrole alkaloids, aspidostomides A-H and aspidazide A (1-9), were isolated from the Patagonian bryozoan Aspidostoma giganteum. Aspidostomides A-H have dibromotyrosine- or bromotryptophan-derived moieties forming either linear amides or pyrroloketopiperazine-type lactams with a bromopyrrole carboxylic acid as a common structural motif. On the other hand, aspidazide A is a rare asymmetric acyl azide formed by an N-N link of two different pyrroloketopiperazine lactams and is the first isolated compound of this class from marine invertebrates. This work is the first report of secondary metabolites isolated from a bryozoan from the Patagonian region. The structures of compounds 1-9 were elucidated by spectroscopic methods and chemical transformations. One of these compounds, aspidostomide E (5), was moderately active against the 786-O renal carcinoma cell line.

Clinical relevance of galectin-1 expression in non-small cell lung cancer patients.

BACKGROUND: Identification of biomarkers in lung cancer, a leading cause of cancer-related mortality, has a meaningful clinical relevance in the quest of novel prognostic factors and therapeutic targets. The glycan-binding protein galectin-1 (Gal-1) modulates tumor progression by mediating cell-cell and cell-extracellular matrix interactions, as well as angiogenesis and tumor immune-escape. Previous works reported the expression of Gal-1 in lung cancer, although its clinical significance remains uncertain. OBJECTIVE: To assess the clinicopathologic relevance and prognostic value of Gal-1 expression in a cohort of 103 Stage I-III non-small cell lung cancer (NSCLC) patients. METHODS: Gal-1 expression was determined by immunohistochemistry in tumor tissue samples. The percentage of immunoreactive tumor cells and stroma, as well as the presence of blood vessels with positively stained endothelium in the tumor and surrounding normal tissue, were recorded. Results were correlated with the clinicopathologic factors of the patients (Spearman's rank correlation coefficient, chi-square test) and overall survival by univariate (Kaplan Meier) and multivariate analyses (Cox regression hazard model). RESULTS: We did not observe significant associations between Gal-1 expression and relevant clinicopathologic features at diagnosis of NSCLC. However, Kaplan Meier analysis revealed a significant association between Gal-1 expression and overall survival, when Gal-1 expression was analyzed on tumor cells alone ("tumor cell percentage") or when an integrated score accounting for tumor cell as well as stromal expression of Gal-1 ("total score") was assessed. Patients showing high Gal-1 expression evidenced a poorer clinical outcome. Furthermore, "total score" remained significantly associated with survival by multivariate Cox regression analysis in the whole cohort of patients, even when controlling for the classical predictors and prognostic factors of NSCLC. CONCLUSION: We conclude that Gal-1 expression may be a useful biomarker for better prediction of the clinical outcome and management of NSCLC patients.

'Reduced malignancy as a mechanism for longevity in mice with adenylyl cyclase type 5 disruption'.

Disruption of adenylyl cyclase type 5 (AC5) knockout (KO) is a novel model for longevity. Because malignancy is a major cause of death and reduced lifespan in mice, the goal of this investigation was to examine the role of AC5KO in protecting against cancer. There have been numerous discoveries in genetically engineered mice over the past several decades, but few have been translated to the bedside. One major reason is that it is difficult to alter a gene in patients, but rather a pharmacological approach is more appropriate. The current investigation employs a parallel construction to examine the extent to which inhibiting AC5, either in a genetic knockout (KO) or by a specific pharmacological inhibitor protects against cancer. This study is unique, not only because a combined genetic and pharmacological approach is rare, but also there are no prior studies on the extent to which AC5 affects cancer. We found that AC5KO delayed age-related tumor incidence significantly, as well as protecting against mammary tumor development in AC5KO × MMTV-HER-2 neu mice, and B16F10 melanoma tumor growth, which can explain why AC5KO is a model of longevity. In addition, a Food and Drug Administration approved antiviral agent, adenine 9-ß-D-arabinofuranoside (Vidarabine or AraAde), which specifically inhibits AC5, reduces LP07 lung and B16F10 melanoma tumor growth in syngeneic mice. Thus, inhibition of AC5 is a previously unreported mechanism for prevention of cancers associated with aging and that can be targeted by an available pharmacologic inhibitor, with potential consequent extension of lifespan.

TGF-beta specifically enhances the metastatic attributes of murine lung adenocarcinoma: implications for human non-small cell lung cancer.

Lung cancer is the most frequent and one of the most deadly cancer types and is classified into small cell lung cancer and non-small cell lung cancer (NSCLC). Transforming growth factor beta (TGFß) regulates a wide array of cell functions and plays a major role in lung diseases, including NSCLC. TGFß signals through the complex of TGFß type I and type II receptors, triggering Smad and non-Smad signaling pathways such as PI3K/Akt and MEK1/ERK. We investigated the role of TGFß1 on the progression of the murine lung adenocarcinoma cell line LP07. Furthermore, we undertook a retrospective study with tissue samples from stage I and II NSCLC patients to assess the clinical pathologic role and prognostic significance of TßRI expression. We demonstrated that although lung cancer cell monolayers responded to TGFß1 anti-mitogenic effects and TGFß1 pulse (24 h treatment) delayed tumor growth at primary site; a switch towards malignant progression upon TGFß1 treatment was observed at the metastatic site. In our model, TGFß1 modulated in vitro clonogenicity, protected against stress-induced apoptosis and increased adhesion, spreading, lung retention and metastatic outgrowth. PI3K and MEK1 signaling pathways were involved in TGFß1-mediated metastasis stimulation. Several of these TGFß responses were also observed in human NSCLC cell lines. In addition, we found that a higher expression of TßRI in human lung tumors is associated with poor patient's overall survival by univariate analysis, while multivariate analysis did not reach statistical significance. Although additional detailed analysis of the endogenous signaling in vivo and in vitro is needed, these studies may provide novel molecular targets for the treatment of lung cancer.

Modulation of pancreatic tumor potential by overexpression of protein kinase C ß1.

OBJECTIVE: This study aimed to investigate whether the overexpression of protein kinase C ß1 (PKCß1) is able to modulate the malignant phenotype displayed by the human ductal pancreatic carcinoma cell line PANC1. METHODS: PKCß1 overexpression was achieved using a stable transfection approach. PANC1-PKCß1 and control cells were analyzed both in vitro and in vivo. RESULTS: PANC1-PKCß1 cells displayed a lower growth capacity associated with the down-regulation of the MEK/ERK pathway and cyclin expression. Furthermore, PKCß1 overexpression was associated with an enhancement of cell adhesion to fibronectin and with reduced migratory and invasive phenotypes. In agreement with these results, PANC1-PKCß1 cells showed an impaired ability to secrete proteolytic enzymes. We also found that PKCß1 overexpressing cells were more resistant to cell death induced by serum deprivation, an event associated with G0/G1 arrest and the modulation of PI3K/Akt and NF-κB pathways. Most notably, the overexpression of PKCß1 completely abolished the ability of PANC1 cells to induce tumors in nude mice. CONCLUSIONS: Our results established an important role for PKCß1 in PANC1 cells suggesting it would act as a suppressor of tumorigenic behavior in pancreatic cancer.

A clinically relevant bi-cellular murine mammary tumor model as a useful tool for evaluating the effect of retinoic acid signaling on tumor progression.

BACKGROUND: The effect of retinoic acid (RA) on breast cancer progression is controversial. Our objective was to obtain information about breast cancer progression, taking advantage of the ER-negative murine mammary adenocarcinoma model LM38 (LM38-LP constituted by luminal (LEP) and myoepithelial-like cells (MEP), LM38-HP mainly composed of spindle-shaped epithelial cells, and LM38-D2 containing only large myoepithelial cells), and to validate the role of the retinoic acid receptors (RARs) in each cell-type compartment. MATERIALS AND METHODS: We studied the expression and functionality of the RARs in LM38 cell lines. We analyzed cell growth and cell cycle distribution, apoptosis, the activity of proteases, motility properties, and expression of the molecules involved in these pathways. We also evaluated tumor growth and dissemination in vivo under retinoid treatment. RESULTS: LM38 cell lines expressed most retinoic receptor isotypes that were functional. However, only the bi-cellular LM38-LP cells responded to retinoids by increasing RARß2 and CRBP1 expression. The growth of LM38 cell sublines was inhibited by retinoids, first by inducing arrest in MEP cells, then apoptosis in LEP cells. Retinoids induced inhibitory effects on motility, invasiveness, and activity of proteolytic enzymes, mainly in the LM38-LP cell line. In in-vivo assays with the LM38-LP cell line, RA treatment impaired both primary tumor growth and lung metastases dissemination. CONCLUSION: These in-vivo and in-vitro results show that to achieve maximum effects of RA on tumor progression both the LEP and MEP cell compartments have to be present, suggesting that the interaction between the LEP and MEP cells is crucial to full activation of the RARs.

TGF-ß autocrine pathway and MAPK signaling promote cell invasiveness and in vivo mammary adenocarcinoma tumor progression.

Breast cancer progression and metastasis have been linked to abnormal signaling by transforming growth factor-ß (TGF-ß) cytokines. In early-stage breast cancers, TGF-ß exhibits tumor suppressor activity by repressing cell proliferation and inducing cell death, whereas in advanced-stage tumors, TGF-ß promotes invasion and metastatic dissemination. The molecular mechanisms underlying pro-oncogenic activities of TGF-ß are not fully understood. The present study validates the role of TGF-ß signaling in cancer progression and explores mediators of pro-oncogenic TGF-ß activities using the LM3 mammary adenocarcinoma cell line, derived from a spontaneous murine mammary adenocarcinoma. Expression of kinase-inactive TGF-ß receptors decreased both basal and TGF-ß-induced invasion. Analysis of signal transduction mediators showed that p38MAPK and MEK contribute to TGF-ß stimulation of cell motility and invasion. TGF-ß disrupted the epithelial actin structures supporting cell-cell adhesions, and increased linear actin filaments. Moreover, MEK and p38MAPK pathways showed opposite effects on actin remodeling in response to TGF-ß. Blockade of Raf-MEK signaling enhanced TGF-ß induction of actin stress-fibers whereas p38MAPK inhibitors blocked this effect. A novel observation was made that TGF-ß rapidly activates the actin nucleation Arp2/3 complex. In addition, TGF-ß stimulated matrix metalloproteinase MMP-9 secretion via a MAPK-independent pathway. Experiments using syngeneic mice showed that kinase-inactive TGF-ß receptors inhibit the first stages of LM3 tumor growth in vivo. Our studies demonstrate that autocrine TGF-ß signaling contributes to the invasive behavior of mammary carcinoma cells. Moreover, we show that both MAPK-dependent and -independent pathways are necessary for TGF-ß-induced effects. Therefore, MEK-ERK and p38 MAPK pathways are potential venues for therapeutic intervention in pro-oncogenic TGF-ß signaling.

Synthesis of steroidal quinones and hydroquinones from bile acids by Barton radical decarboxylation and benzoquinone addition. Studies on their cytotoxic and antifungal activities.

Twelve new hydroquinones and quinones (4a-c to 7a-c) derived from free or peracetylated bile acids were prepared by a Barton decarboxylation reaction, with subsequent trapping of the resulting free radical by benzoquinone. All new compounds were completely characterized by 2D NMR techniques and screened for antifungal and cytotoxic activity. One of the new hydroquinones (7b) showed promising results against the human pancreatic ductal carcinoma cell line PANC1, with similar cytotoxic activity as the commercial chemotherapy drug doxorubicin.

Estrogen receptor ß and epidermal growth factor receptor as early-stage prognostic biomarkers of non-small cell lung cancer.

As 20% of stage I NSCLC patients develop recurrent and often incurable cancer, the identification of prognostic markers has a meaningful clinical application. The biological significance of steroid hormone and EGF receptors, able to regulate key physiological functions, remains elusive in NSCLC. Our aim was to investigate the prognostic input of estrogen receptors (ERα, ERß), progesterone receptors (PR) and EGFR in tumors from 58 stage I NSCLC patients. Antigen expression was analyzed by immunohistochemistry. Prognostic evaluation was performed with the multivariate Cox model. We found that about 70 and 40% of samples expressed ERα or ERß at cytoplasmic or nuclear level, respectively. Besides, only 12.1% of samples weakly expressed nuclear PR and 62.7% showed membrane EGFR staining. Correlation studies indicated an inverse association between EGFR expression and smoking status (p<0.01). Multivariate studies showed that the lack of nuclear ERß or the loss of EGFR expression were independent prognosis markers associated with shorter overall survival. We also found that patients whose tumors were negative for these two biomarkers presented the worst outcome. In conclusion, our findings could be useful for selecting stage I NSCLC patients with poor prognosis to apply an earlier treatment that impacts on survival.

Dolabellane Diterpenoids from the South Atlantic Gorgonian Convexella magelhaenica.

Two new dolabellane diterpenoids (1 and 2) were isolated from a small sample of the deep water gorgonian octocoral Convexella magelhaenica collected as a nontarget by-catch by dredging (-93 m) in commercial Patagonian scallop fishing grounds in the South Atlantic. The structures of the new compounds, which are major metabolites in the extract, were established by spectroscopic techniques and chemical transformations. Both compounds were cytotoxic against a human pancreatic adenocarcinoma cell line at micromolar concentrations.

Cytotoxic terpenoids from Nardophyllum bryoides.

The investigation of the ethanol extract of fresh aerial parts of the Patagonian shrub Nardophyllum bryoides collected in the province of Chubut, Argentina, yielded eleven terpenoids. These include: three seco-ent-halimane diterpenoids (1-3), two ent-halimanes (4-5) and six pentacyclic oleanane and ursane triterpenoids (6-11). Four of these compounds (2, 6, 8 and 11) are hitherto unknown, while two others (1 and 4) have been previously reported but only as synthetic products. Several of these compounds showed moderate cytotoxicity against a human pancreatic adenocarcinoma cell line while compounds 4 and 5 were active at micromolar concentrations. The main component, seco-chiliolidic acid (1), could be isolated from this extract in large amounts, turning N. bryoides into a sustainable source of this bioactive compound.

The neural cell adhesion molecule is involved in the metastatic capacity in a murine model of lung cancer.

Neural cell adhesion molecule (NCAM) is involved in cell growth, migration, and differentiation. Its expression and/or polysialylation appear to be deregulated in many different cancer types. We employed the lung tumor cell line LP07, syngeneic in BALB/c mice to investigate the role of NCAM in malignant progression. LP07 cells express the three main NCAM isoforms, all of them polysialylated. This cells line, pretreated with an anti-NCAM antibody and inoculated intravenously (i.v.) into syngeneic mice, developed less and smaller lung metastases. In vitro studies showed that NCAM bound antibody inhibited cell growth, mainly due to an increase in apoptosis, associated with a decrease of cyclin D1 and enhanced expression of active caspase 3 and caspase 9. Anti-NCAM-treated LP07 cells showed impairment in their ability to migrate and adhere to several extracellular matrix components. Secreted uPA activity was also reduced. NCAM-140 knocked-down by siRNA in LP07 cells pretreated or not with anti-NCAM showed an impaired metastasizing ability upon i.v. inoculation into mice. These results suggest that anti-NCAM treatment could be mimicking homophilic trans-interactions and NCAM-140 knocked-down impairs heterophilic interactions, both leading to inhibition of metastatic dissemination. The involvement of NCAM in lung tumor progression was confirmed in human NSCLC tumors. Sixty percent of the cases expressed NCAM at tumor cell level. A multivariate analysis indicated that NCAM expression was associated with a shorter overall survival in this homogeneous series of Stages I and II NSCLC patients. NCAM may be able to modulate mechanisms involved in lung carcinoma progression and represents an attractive target to control metastatic progression.

Mast cell phenotypes and microvessels in non-small cell lung cancer and its prognostic significance.

The impact of interstitial inflammatory cells, such as mast cells, and angiogenesis on the prognosis of cancer patients has been reported in many solid tumors, although there is disagreement about their role. We undertook a retrospective study with tissue samples from 65 patients with stage I and II non-small cell lung cancer to assess the clinical pathologic role and prognostic significance of mast cells. Mast cell phenotypes were identified by immunohistochemistry for tryptase and chymase. In addition, we identified microvessels using the endothelial marker CD34. Mast cell and microvessel density was quantified by assessing immunopositive cells in the intratumoral and peritumoral zones of tumor specimens. Both mast cell and microvessel density was higher in the peritumoral zone than the intratumoral zone (P

PKC Delta (PKCdelta) promotes tumoral progression of human ductal pancreatic cancer.

OBJECTIVE: Our objective was to study the role of protein kinase C delta (PKCdelta) in the progression of human pancreatic carcinoma. METHODS: Protein kinase C delta expression in human ductal carcinoma (n = 22) was studied by immunohistochemistry. We analyzed the effect of PKCdelta overexpression on in vivo and in vitro properties of human ductal carcinoma cell line PANC1. RESULTS: Human ductal carcinomas showed PKCdelta overexpression compared with normal counterparts. In addition, in vitro PKCdelta-PANC1 cells showed increased anchorage-independent growth and higher resistance to serum starvation and to treatment with cytotoxic drugs. Using pharmacological inhibitors, we determined that phosphatidylinositol-3-kinase and extracellular receptor kinase pathways were involved in the proliferation of PKCdelta-PANC1. Interestingly, PKCdelta-PANC1 cells showed a less in vitro invasive ability and an impairment in their ability to migrate and to secrete the proteolytic enzyme matrix metalloproteinase-2. In vivo experiments indicated that PKCdelta-PANC1 cells were more tumorigenic, as they developed tumors with a significantly lower latency and a higher growth rate with respect to the tumors generated with control cells. Besides, only PKCdelta-PANC1 cells developed lung metastasis. CONCLUSION: Our results showed that the overexpression of PKCdelta in PANC1 cells induced a more malignant phenotype in vivo, probably through the modulation of cell proliferation and survival, involving phosphatidylinositol-3-kinase and extracellular receptor kinase signaling pathways.

Generation and characterization of human insulin-releasing cell lines.

BACKGROUND: The in vitro culture of insulinomas provides an attractive tool to study cell proliferation and insulin synthesis and secretion. However, only a few human beta cell lines have been described, with long-term passage resulting in loss of insulin secretion. Therefore, we set out to establish and characterize human insulin-releasing cell lines. RESULTS: We generated ex-vivo primary cultures from two independent human insulinomas and from a human nesidioblastosis, all of which were cultured up to passage number 20. All cell lines secreted human insulin and C-peptide. These cell lines expressed neuroendocrine and islets markers, confirming the expression profile found in the biopsies. Although all beta cell lineages survived an anchorage independent culture, none of them were able to invade an extracellular matrix substrate. CONCLUSION: We have established three human insulin-releasing cell lines which maintain antigenic characteristics and insulin secretion profiles of the original tumors. These cell lines represent valuable tools for the study of molecular events underlying beta cell function and dysfunction.

Glypican-3 regulates migration, adhesion and actin cytoskeleton organization in mammary tumor cells through Wnt signaling modulation.

Glypican-3 (GPC3) is a proteoglycan involved in migration, proliferation and cell survival modulation in several tissues. There are many reports demonstrating a downregulation of GPC3 expression in some human tumors, including mesothelioma, ovarian and breast cancer. Previously, we determined that GPC3 reexpression in the murine mammary adenocarcinoma LM3 cells induced an impairment of their in vivo invasive and metastatic capacities together with a higher susceptibility to in vitro apoptosis. Currently, the signaling mechanism of GPC3 is not clear. First, it was speculated that GPC3 regulates the insulin-like growth factor (IGF) signaling system. This hypothesis, however, has been strongly challenged. Recently, several reports indicated that at least in some cell types GPC3 serves as a selective regulator of Wnt signaling. Here we provide new data demonstrating that GPC3 regulates Wnt pathway in the metastatic adenocarcinoma mammary LM3 cell line. We found that GPC3 is able to inhibit canonical Wnt signals involved in cell proliferation and survival, as well as it is able to activate non canonical pathway, which directs cell morphology and migration. This is the first report indicating that breast tumor cell malignant properties can be reverted, at least in part, by GPC3 modulation of Wnt signaling. Our results are consistent with the potential role of GPC3 as a metastasis suppressor.

Expression pattern of glypican-3 (GPC3) during human embryonic and fetal development.

Glypicans represent a family of cell surface proteoglycans. Loss-of-function mutations in the human glypican-3 (GPC3) gene results in the Simpson-Golabi-Behmel syndrome, characterized by severe malformations and pre- and postnatal overgrowth. Because the expression of GPC3 during human embryonic and fetal periods remains largely unknown, we investigated by immunohistochemistry its pattern of expression during four periods of human development covering the embryonic period (P1) from 5 to 8 weeks of development, and the fetal periods (P2, P3 and P4) from 9 to 28 weeks of development. Hepatocytes were homogeneously positive for GPC3 during the four periods while pancreatic acini and ducts showed a rather high staining only during P1. GPC3 was also detected in several kidney structures and in the genital system where the sex cords were weakly positive in P1 and P2. In later developmental stages the male's genital system expressed GPC3 while the female's did not. While the mesenchyme in the limbs showed positive staining in P1, GPC3 was not detected during the following stages. The mesenchymal tissue localized between the most caudal vertebrae was also positive in P1. A strong GPC3 signal was observed in neurons of the spinal cord and dorsal root ganglia in P2 and P3, while the brain was negative. In sum our studies revealed that GPC3 expression is highly tissue- and stage-specific during human development. The expression pattern of GPC3 is consistent with the abnormalities seen in the Simpson-Golabi-Behmel syndrome.

[Retinoid expression (RARbeta and CRBP1) in non-small-cell lung carcinoma]. / Retinoides (RARbeta y CRBP1) en carcinoma de pulmón a celulas no pequeñas.

Although early-stage non-small-cell lung carcinoma (NSCLC) patients have a relative by favorable prognosis, the risk of a bad outcome remains substantial. Identification of reliable prognostic markers for disease recurrence and death has meaningful clinical application. Retinoids are involved in cell growth and differentiation and may antagonize cancer progression. Their effects are mediated through nuclear receptors called Retinoic Acid Receptor (RAR) and regulated by molecules such as Cellular Retinol-Binding Protein 1 (CRBP1) that function in retinol storage. The aim of this work was to analyze by immunohistochemistry the expression patterns of RARbeta and CRBP1, involved in retinoid-mediated signaling, in the tumoral tissue of a cohort of stage I/II NSCLC patients (n = 49) who underwent a successful surgical resection. Prognostic evaluation was performed with the multivariate Cox proportional hazard model: 44.9% of tumors were positive for RARbeta staining at cytoplasmic level, while 34.7% showed nuclear staining. CRBP1 staining was observed in 61.2% of the lung tumors. No relationship was found between the number of cells expressing the studied molecules and clinical pathological features, including sex, T and N (stage), histopathology and p53 expression. Univariate analysis showed a significant association between positive cytoplasmatic expression of RARbeta with shorter overall survival (Log-rank test 4.17, p = 0.0412). Multivariate studies indicated that RARbeta expression was not influenced by other clinical pathological parameters. In conclusion, in this cohort of stage I and II NSCLC, only the expression of RARbeta at cytoplasmatic level is a significant independent unfavorable prognostic factor.