Showing papers by "Lance D. Miller published in 2010"

Targeting aldehyde dehydrogenase cancer stem cells in ovarian cancer

Abstract: Aldehyde dehydrogenase-1A1 (ALDH1A1) expression characterizes a subpopulation of cells with tumor-initiating or cancer stem cell properties in several malignancies. Our goal was to characterize the phenotype of ALDH1A1-positive ovarian cancer cells and examine the biological effects of ALDH1A1 gene silencing. In our analysis of multiple ovarian cancer cell lines, we found that ALDH1A1 expression and activity was significantly higher in taxane- and platinum-resistant cell lines. In patient samples, 72.9% of ovarian cancers had ALDH1A1 expression in which the percentage of ALDH1A1-positive cells correlated negatively with progression-free survival (6.05 vs. 13.81 months; P < 0.035). Subpopulations of A2780cp20 cells with ALDH1A1 activity were isolated for orthotopic tumor-initiating studies, where tumorigenicity was approximately 50-fold higher with ALDH1A1-positive cells. Interestingly, tumors derived from ALDH1A1-positive cells gave rise to both ALDH1A1-positive and ALDH1A1-negative populations, but ALDH1A1-negative cells could not generate ALDH1A1-positive cells. In an in vivo orthotopic mouse model of ovarian cancer, ALDH1A1 silencing using nanoliposomal siRNA sensitized both taxane- and platinum-resistant cell lines to chemotherapy, significantly reducing tumor growth in mice compared with chemotherapy alone (a 74%-90% reduction; P < 0.015). These data show that the ALDH1A1 subpopulation is associated with chemoresistance and outcome in ovarian cancer patients, and targeting ALDH1A1 sensitizes resistant cells to chemotherapy. ALDH1A1-positive cells have enhanced, but not absolute, tumorigenicity but do have differentiation capacity lacking in ALDH1A1-negative cells. This enzyme may be important for identification and targeting of chemoresistant cell populations in ovarian cancer.

Ferroportin and iron regulation in breast cancer progression and prognosis.

Abstract: Ferroportin and hepcidin are critical proteins for the regulation of systemic iron homeostasis. Ferroportin is the only known mechanism for export of intracellular non–heme-associated iron; its stability is regulated by the hormone hepcidin. Although ferroportin profoundly affects concentrations of intracellular iron in tissues important for systemic iron absorption and trafficking, ferroportin concentrations in breast cancer and their influence on growth and prognosis have not been examined. We demonstrate here that both ferroportin and hepcidin are expressed in cultured human breast epithelial cells and that hepcidin regulates ferroportin in these cells. Further, ferroportin protein is substantially reduced in breast cancer cells compared to nonmalignant breast epithelial cells; ferroportin protein abundance correlates with metabolically available iron. Ferroportin protein is also present in normal human mammary tissue and markedly decreased in breast cancer tissue, with the highest degree of anaplasia associated with lowest ferroportin expression. Transfection of breast cancer cells with ferroportin significantly reduces their growth after orthotopic implantation in the mouse mammary fat pad. Gene expression profiles in breast cancers from >800 women reveal that decreased ferroportin gene expression is associated with a significant reduction in metastasis-free and disease-specific survival that is independent of other breast cancer risk factors. High ferroportin and low hepcidin gene expression identifies an extremely favorable cohort of breast cancer patients who have a 10-year survival of >90%. Ferroportin is a pivotal protein in breast biology and a strong and independent predictor of prognosis in breast cancer.

Neurotensin receptor 1 determines the outcome of non-small cell lung cancer.

Abstract: Purpose: This study aimed to investigate the role of the neurotensin/neurotensin receptor I (NTSR1) complex in non–small cell lung cancer (NSCLC) progression. Experimental Design: The expression of neurotensin and NTSR1 was studied by transcriptome analysis and immunohistochemistry in two series of 74 and 139 consecutive patients with pathologic stage I NSCLC adenocarcinoma. The findings were correlated with clinic-pathologic features. Experimental tumors were generated from the malignant human lung carcinoma cell line A459, and a subclone of LNM35, LNM-R. The role of the neurotensin signaling system on tumor growth and metastasis was investigated by small hairpin RNA–mediated silencing of NTSR1 and neurotensin. Results: Transcriptome analysis carried out in a series of 74 patients showed that the positive regulation of NTSR1 put it within the top 50 genes related with relapse-free survival. Immunohistochemistry revealed neurotensin- and NTSR1-positive staining in 60.4% and 59.7% of lung adenocarcinomas, respectively. At univariate analysis, NTSR1 expression was strongly associated with worse 5-year overall survival rate (P = 0.0081) and relapse-free survival (P = 0.0024). Multivariate analysis showed that patients over 65 years of age (P = 0.0018) and NTSR1 expression (P = 0.0034) were independent negative prognostic factors. Experimental tumor xenografts generated by neurotensin- and NTSR1-silenced human lung cancer cells revealed that neurotensin enhanced primary tumor growth and production of massive nodal metastasis via autocrine and paracrine regulation loops. Conclusion: NTSR1 expression was identified as a potential new prognostic biomarker for surgically resected stage I lung adenocarcinomas, as NTSR1 activation was shown to participate in lung cancer progression. Clin Cancer Res; 16(17); 4401–10. ©2010 AACR.

Artemin is estrogen regulated and mediates antiestrogen resistance in mammary carcinoma

Abstract: We have previously identified an oncogenic role of artemin (ARTN), a member of glial cell derived neurotrophic factor family of ligands, in mammary carcinoma. We herein report that ARTN is an estrogen-inducible gene. Meta-analysis of gene expression data sets showed that ARTN expression is positively correlated to estrogen receptor (ER) status in human mammary carcinoma. Furthermore, in patients with ER-positive mammary carcinoma treated with tamoxifen, high ARTN expression is significantly correlated with decreased survival. Forced expression of ARTN in ER-positive human mammary carcinoma cells increased ER transcriptional activity, promoted estrogen-independent growth and produced resistance to tamoxifen and fulvestrant in vitro and to tamoxifen in xenograft models. ARTN-stimulated resistance to tamoxifen and fulvestrant is mediated by increased BCL-2 expression. Conversely, depletion of endogenous ARTN by small-interfering RNA or functional antagonism of ARTN by antibody enhanced the efficacy of antiestrogens. Tamoxifen decreased ARTN expression in tamoxifen-sensitive mammary carcinoma cells whereas ARTN expression was increased in tamoxifen-resistant cells and not affected by tamoxifen treatment. Antibody inhibition of ARTN in tamoxifen-resistant cells improved tamoxifen sensitivity. Functional antagonism of ARTN therefore warrants consideration as an adjuvant therapy to enhance antiestrogen efficacy in ER-positive mammary carcinoma.

Establishment and metabolic analysis of a model microbial community for understanding trophic and electron accepting interactions of subsurface anaerobic environments

Abstract: Communities of microorganisms control the rates of key biogeochemical cycles, and are important for biotechnology, bioremediation, and industrial microbiological processes. For this reason, we constructed a model microbial community comprised of three species dependent on trophic interactions. The three species microbial community was comprised of Clostridium cellulolyticum, Desulfovibrio vulgaris Hildenborough, and Geobacter sulfurreducens and was grown under continuous culture conditions. Cellobiose served as the carbon and energy source for C. cellulolyticum, whereas D. vulgaris and G. sulfurreducens derived carbon and energy from the metabolic products of cellobiose fermentation and were provided with sulfate and fumarate respectively as electron acceptors. qPCR monitoring of the culture revealed C. cellulolyticum to be dominant as expected and confirmed the presence of D. vulgaris and G. sulfurreducens. Proposed metabolic modeling of carbon and electron flow of the three-species community indicated that the growth of C. cellulolyticum and D. vulgaris were electron donor limited whereas G. sulfurreducens was electron acceptor limited. The results demonstrate that C. cellulolyticum, D. vulgaris, and G. sulfurreducens can be grown in coculture in a continuous culture system in which D. vulgaris and G. sulfurreducens are dependent upon the metabolic byproducts of C. cellulolyticum for nutrients. This represents a step towards developing a tractable model ecosystem comprised of members representing the functional groups of a trophic network.

Trefoil Factor 3 Is Oncogenic and Mediates Anti-Estrogen Resistance in Human

Abstract: We report herein that trefoil factor 3 (TFF3) is oncogenic and mediates anti–estrogen resistance in human mammary carcinoma. Forced expression of TFF3 in mammary carcinoma cells increased cell proliferation and survival, enhanced anchorage-independent growth, and promoted migration and invasion. Moreover, forced expression of TFF3 increased tumor size in xenograft models. Conversely, depletion of endogenous TFF3 with small interfering RNA (siRNA) decreased the oncogenicity and invasiveness of mammary carcinoma cells. Neutralization of secreted TFF3 by antibody promoted apoptosis, decreased cell growth in vitro ,a nd arrested mammary carcinoma xenograft growth. TFF3 expression was significantly correlated to decreased survival of estrogen receptor (ER)–positive breast cancer patients treated with tamoxifen. Forced expression of TFF3 in mammary carcinoma cells increased ER transcriptional activity, promoted estrogen-independent growth, and produced resistance to tamoxifen and fulvestrant in vitro and to tamoxifen in xenograft models. siRNA-mediated depletion or antibody inhibition of TFF3 significantly enhanced the efficacy of antiestrogens. Increased TFF3 expression was observed in tamoxifen-resistant (TAMR) cells and antibody inhibition of TFF3 in TAMR cells improved tamoxifen sensitivity. Functional antagonism of TFF3 therefore warrants consideration as a novel therapeutic strategy for mammary carcinoma.

Diagnostic and prognostic markers for cancer

Abstract: Methods of predicting the risk of cancer recurrence based on expression levels of at least two iron homeostasis-associated markers are disclosed.

A method for the systematic evaluation of the prognostic properties of gene pairs for medical conditions, and certain gene pairs identified

Abstract: A method is proposed identification of pairs of genes for which the respective gene expression values in a subject are statistically significant in relation to a medical condition, for example cancer, or more particularly breast cancer. Many pairs of genes are generated, and for each pair of genes clinical data is used to fit a statistical model to obtain the statistical significance of the ratio of the corresponding expression values. The clinical data characterizes for each of the patients the level of expressions of the genes and times until a clinical endpoint of interest.

A biomarker and treatment for cancer

Abstract: A correlation between expression of JMJD6 polypeptide and breast cancer metastasis exists accordingly the present invention relates a diagnostic, prognostic and therapeutic biomarker to distinguish between early and advanced/metastatic cancer particularly breast cancer, including compounds and methods to treat the same.

Abstract 4288: Targeted therapy against aldehyde dehydrogenase in ovarian cancer

Abstract: Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC OBJECTIVE. Aldehyde dehydrogenase-1 (ALDH1) expression characterizes a subpopulation of cells with enhanced tumor initiating and differentiating properties in some cancers. We have examined the association of ALDH1 with chemoresistance and whether downregulation of ALDH1 sensitizes cells to chemotherapy in models of ovarian cancer. METHODS. Microarray profiling was performed on SKOV3ip1 and the taxane-resistant SKOV3TRip2 cell lines. Primary ovarian cancer xenografts with and without cisplatin exposure were examined for selection of ALDH1-positive cells. Small interfering RNA (siRNA) was used to downregulate ALDH1 in vitro, and in vivo by incorporation into neutral DOPC liposomes, for evaluation of chemosensitization in an orthotopic model of ovarian cancer. RESULTS. Microarray analysis found 29 genes upregulated and 18 genes downregulated by more than 10-fold when comparing the taxane-resistant SKOV3TRip2 ovarian cancer line compared to its parental SKOV3ip1 line. Included among these was a 92.7-fold higher ALDH1 signature. Increased expression and activity of ALDH1 was confirmed by Western blot and the ALDEFLUOR assay (58% of cells ALDH1-active). In primary ovarian cancer xenografts in NOD-Scid mice, cisplatin treatment resulted in an increase in ALDH1-positive cells, from a baseline of 1% to 38% with therapy (p<0.001). ALDH1-positive cells were not limited to perivascular, hypoxic, or advancing edge regions of the tumor. SiRNA constructs downregulating expression of ALDH1 were identified, and reduced viability of SKOV3TRip2 cells in vitro by 49% (p<0.001). ALDH1 targeting also reduced the docetaxel IC50 from 178nM to 82nM. In the A2780cp20 cell line (a cisplatin-resistant cell line derived from A2780), ALDH1 siRNA alone reduced growth by just 16%, but sensitized cells to cisplatin with a reduction in IC50 from 5.1 to 2.0μM. In an in vivo orthotopic model of ovarian cancer, we treated mice with control siRNA, ALDH1-siRNA incorporated into DOPC liposomes, chemotherapy, or combined chemo/ALDH1-siRNA-DOPC. ALDH1 alone or docetaxel alone had minimal effect on SKOV3TRip2 tumor growth, but ALDH1-siRNA-DOPC plus docetaxel reduced growth by 89.8% compared to docetaxel/control siRNA (p=0.003). Similarly, in the A2780cp20 model, ALDH1-siRNA-DOPC alone or cisplatin had a nonsignificant reduction, while ALDH1-siRNA-DOPC plus cisplatin reduced tumor growth by 73.4% compared to cisplatin/control siRNA (p=0.013). CONCLUSIONS. ALDH1 expression is associated with taxane and cisplatin chemoresistance in ovarian cancer cell lines. ALDH1 expression can be induced by cisplatin treatment in vivo, and targeting ALDH1 sensitizes resistant cell lines to chemotherapy. This enzyme may be important for identification and targeting the chemoresistant population in ovarian cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4288.

Biomarqueur et traitement pour le cancer

Abstract: Une correlation existe entre l'expression du polypeptide JMJD6 et des metastases du cancer du sein. En consequence, l'invention concerne un biomarqueur de diagnostic, de pronostic et therapeutique permettant de faire la distinction entre un cancer precoce et un cancer avance/metastasique, en particulier pour le cancer du sein, y compris des composes et des procedes de traitement correspondants.

A method, system and computer program product for the systematic evaluation of the prognostic properties of gene pairs for medical conditions.

Abstract: A method of obtaining cut-off expression values should be selected so as to maximise the separation of the respective survival curves of the two groups of patients. Pairs of genes are statistically significant genes are generated by generating a plurality of models, each of which represents a way of partitioning a set of subjects based on the optimal cut-off expression values of the pair of genes. Those gene pairs are identified for which one of the models has a high prognostic significance. Novel survival significant gene sets forming functional modules which could be used to develop specific prognostic and predictive tests are derived.