Mutually exclusive expression of DLX2 and DLX5/6 is associated with the metastatic potential of the human breast cancer cell line MDA-MB-231

<p>Abstract</p> <p>Background</p> <p>The <it>DLX </it>gene family encodes for homeobox transcription factors involved in the control of morphogenesis and tissue homeostasis. Their expression can be regulated by Endothelin1 (ET1), a peptide associated with breast cancer invasive phenotype. Deregulation of <it>DLX </it>gene expression was found in human solid tumors and hematologic malignancies. In particular, <it>DLX4 </it>overexpression represents a possible prognostic marker in ovarian cancer. We have investigated the role of <it>DLX </it>genes in human breast cancer progression.</p> <p>Methods</p> <p>MDA-MB-231 human breast carcinoma cells were grown in vitro or injected in nude mice, either subcutaneously, to mimic primary tumor growth, or intravenously, to mimic metastatic spreading. Expression of <it>DLX2</it>, <it>DLX5 </it>and <it>DLX6 </it>was assessed in cultured cells, either treated or not with ET1, tumors and metastases by RT-PCR. <it>In situ </it>hybridization was used to confirm <it>DLX </it>gene expression in primary tumors and in lung and bone metastases. The expression of <it>DLX2 </it>and <it>DLX5 </it>was evaluated in 408 primary human breast cancers examining the GSE1456 and GSE3494 microarray datasets. Kaplan-Meier estimates for disease-free survival were calculated for the patients grouped on the basis of <it>DLX2</it>/<it>DLX5 </it>expression.</p> <p>Results</p> <p>Before injection, or after subcutaneous growth, MDA-MB-231 cells expressed <it>DLX2 </it>but neither <it>DLX5 </it>nor <it>DLX6</it>. Instead, in bone and lung metastases resulting from intravenous injection we detected expression of <it>DLX5/6 </it>but not of <it>DLX2</it>, suggesting that <it>DLX5/6 </it>are activated during metastasis formation, and that their expression is alternative to that of <it>DLX2</it>. The <it>in vitro </it>treatment of MDA-MB-231 cells with ET1, resulted in switch from <it>DLX2 </it>to <it>DLX5 </it>expression. By data mining in microarray datasets we found that expression of <it>DLX2 </it>occurred in 21.6% of patients, and was significantly correlated with prolonged disease-free survival and reduced incidence of relapse. Instead, <it>DLX5 </it>was expressed in a small subset of cases, 2.2% of total, displaying reduced disease-free survival and high incidence of relapse which was, however, non-significantly different from the other groups due to the small size of the <it>DLX+ </it>cohort. In all cases, we found mutually exclusive expression of <it>DLX2 </it>and <it>DLX5</it>.</p> <p>Conclusions</p> <p>Our studies indicate that <it>DLX </it>genes are involved in human breast cancer progression, and that <it>DLX2 </it>and <it>DLX5 </it>genes might serve as prognostic markers.</p

Multifocal Signal Modulation Therapy by Celecoxib: A Strategy for Managing Castration-Resistant Prostate Cancer

Background: Prostate cancer (PCa) is a significant health concern throughout the world. Standard therapy for advanced disease consists of anti-androgens, however, almost all prostate tumors become castration resistant (CRPC). Progression from androgen-sensitive PCa to CRPC is promoted by inflammatory signaling through cyclooxygenase-2 (COX-2) expression and ErbB family receptors/AKT activation, compensating androgen receptor inactivity. Methods: Making use of CRPC cell lines, we investigated the effects of the anti-inflammatory drug celecoxib. Biochemical data obtained using immunoblotting, enzyme-linked immunosorbent assay (ELISA), invasion, and xenografts were further integrated by bioinformatic analyses. Results: Celecoxib reduced cell growth and induced apoptosis through AKT blockade, cleavage of poly (ADP-ribose) polymerase-1 (PARP-1), and proteasomal degradation of the anti-apoptotic protein Mcl-1. Epidermal growth factor receptor (EGFR), ErbB2, and ErbB3 degradation, and heterogeneous nuclear ribonucleoprotein K (hnRNP K) downregulation, further amplified the inhibition of androgen signaling. Celecoxib reduced the invasive phenotype of CRPC cells by modulating NF-&kappa;B activity and reduced tumor growth in mice xenografts when administered in association with the anti-EGFR receptor antibody cetuximab. Bioinformatic analyses on human prostate cancer datasets support the relevance of these pathways in PCa progression. Conclusions: Signaling nodes at the intersection of pathways implicated in PCa progression are simultaneously modulated by celecoxib treatment. In combination therapies with cetuximab, celecoxib could represent a novel therapeutic strategy to curb signal transduction during CRPC progression

Eosinophil Granulocytes Account for Indoleamine 2,3-Dioxygenase-Mediated Immune Escape in Human Non-Small Cell Lung Cancer

Indoleamine 2,3-dioxygenase (IDO), a catabolizing enzyme of tryptophan, is supposed to play a role in tumor immune escape. Its expression in solid tumors has not yet been well elucidated: IDO can be expressed by the tumor cells themselves, or by ill-defined infiltrating cells, possibly depending on tumor type. We have investigated IDO expression in 25 cases of non-small cell lung cancer (NSCLC). Using histochemistry and immunohistochemistry, we found that IDO was expressed not by tumor cells, but by normal cells infiltrating the peritumoral stroma. These cells were neither macrophages nor dendritic cells, and were identified as eosinophil granulocytes. The amount of IDO-positive eosinophils varied in different cases, ranging from a few cells to more than 50 per field at x200 magnification. IDO protein in NSCLC was enzymatically active. Therefore, at least in NSCLC cases displaying a large amount of these cells in the inflammatory infiltrate, IDO-positive eosinophils could exert an effective immunosuppressive action. On analyzing the 17 patients with adequate follow-up, a significant relationship was found between the amount of IDO-positive infiltrate and overall survival. This finding suggests that the degree of IDO-positive infiltrate could be a prognostic marker in NSCLC

Spatio-temporal dynamics of gene expression of the Edn1-Dlx5/6 pathway during development of the lower jaw

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Transgenic mice overexpressing arginase 1 in monocytic cell lineage are affected by lympho-myeloproliferative disorders and disseminated intravascular coagulation

9noneArginase (ARG) is a metabolic enzyme present in two isoforms that hydrolyze l-arginine to urea and ornithine. In humans, ARG isoform 1 is also expressed in cells of the myeloid lineage. ARG activity promotes tumour growth and inhibits T lymphocyte activation. However, the two ARG transgenic mouse lines produced so far failed to show such effects. We have generated, in two different genetic backgrounds, transgenic mice constitutively expressing ARG1 under the control of the CD68 promoter in macrophages and monocytes. Both heterozygous and homozygous transgenic mice showed a relevant increase in mortality at early age, compared with wild-type siblings (67/267 and 48/181 versus 8/149, respectively, both P < 0.005). This increase was due to high incidence of haematologic malignancies, in particular myeloid leukaemia, myeloid dysplasia, lymphomas and disseminated intravascular coagulation (DIC), diseases that were absent in wild-type mice. Atrophy of lymphoid organs due to reduction in T-cell compartment was also detected. Our results indicate that ARG activity may participate in the pathogenesis of lymphoproliferative and myeloproliferative disorders, suggest the involvement of alterations of L-arginine metabolism in the onset of DIC and confirm a role for the enzyme in regulating T-cell homeostasis.noneAstigiano, Simonetta; Morini, Monica; Damonte, Patrizia; Fraternali Orcioni, Giulio; Cassanello, Michela; Puglisi, Andrea; Noonan, Douglas; Bronte, Vincenzo; Barbieri, OttaviaAstigiano, Simonetta; Morini, Monica; Damonte, Patrizia; Fraternali Orcioni, Giulio; Cassanello, Michela; Puglisi, Andrea; Noonan, Douglas; Bronte, Vincenzo; Barbieri, Ottavi