RSK3 switches cell fate: from stress-induced senescence to malignant progression.

Background: TGFβ induces several cell phenotypes including senescence, a stable cell cycle arrest accompanied by a secretory program, and epithelial-mesenchymal transition (EMT) in normal epithelial cells. During carcinogenesis cells lose the ability to undergo senescence in response to TGFβ but they maintain an EMT, which can contribute to tumor progression. Our aim was to identify mechanisms promoting TGFβ-induced senescence escape.

Ephrin-B1 Is a Novel Biomarker of Bladder Cancer Aggressiveness. Studies in Murine Models and in Human Samples.

Bladder cancer (BC) is the ninth most common cancer worldwide, but molecular changes are still under study. During tumor progression, Epithelial cadherin (E-cadherin) expression is altered and β-catenin may be translocated to the nucleus, where it acts as co-transcription factor of tumor invasion associated genes. This investigation further characterizes E-cadherin and β-catenin associated changes in BC, by combining bioinformatics, an experimental murine cell model (MB49/MB49-I) and human BC samples.

Inhibition of breast tumor growth by N(G)-nitro-l-arginine methyl ester (l-NAME) is accompanied by activation of fibroblasts.

Nitric Oxide (NO) is involved in many physiological and pathological processes. It is generated by a family of NO synthases (NOS), being the inducible isoform, iNOS, responsible for higher amounts of NO. Here, we report that pharmacological inhibition of NO production by l-NAME reduces both viability and MAPK activated signalling pathways in iNOS positive human and murine cancer cell lines.

Coronin 1C promotes triple-negative breast cancer invasiveness through regulation of MT1-MMP traffic and invadopodia function.

Membrane type 1-matrix metalloproteinase (MT1-MMP), a membrane-tethered protease, is key for matrix breakdown during cancer invasion and metastasis. Assembly of branched actin networks by the Arp2/3 complex is required for MT1-MMP traffic and formation of matrix-degradative invadopodia. Contrasting with the well-established role of actin filament branching factor cortactin in invadopodia function during cancer cell invasion, the contribution of coronin-family debranching factors to invadopodia-based matrix remodeling is not known.

Social networking in tumor cell communities is associated with increased aggressiveness.

Extracellular vesicles (EVs) are lipid-bilayer-enclosed vesicles that contain proteins, lipids and nucleic acids. EVs produced by cells from healthy tissues circulate in the blood and body fluids, and can be taken up by unrelated cells. As they have the capacity to transfer cargo proteins, lipids and nucleic acids (mostly mRNAs and miRNAs) between different cells in the body, EVs are emerging as mediators of intercellular communication that could modulate cell behavior, tissue homeostasis and regulation of physiological functions.

Cellular and Molecular Mechanisms of MT1-MMP-Dependent Cancer Cell Invasion.

Metastasis is responsible for most cancer-associated deaths. Accumulating evidence based on 3D migration models has revealed a diversity of invasive migratory schemes reflecting the plasticity of tumor cells to switch between proteolytic and nonproteolytic modes of invasion. Yet, initial stages of localized regional tumor dissemination require proteolytic remodeling of the extracellular matrix to overcome tissue barriers.

LIN7A is a major determinant of cell-polarity defects in breast carcinomas.

Background: Polarity defects are a hallmark of most carcinomas. Cells from invasive micropapillary carcinomas (IMPCs) of the breast are characterized by a striking cell polarity inversion and represent an interesting model for the analysis of polarity abnormalities.

Methods: In-depth investigation of polarity proteins in 24 IMPCs and a gene expression profiling, comparing IMPC (n = 73) with invasive carcinomas of no special type (ICNST) (n = 51) have been performed.

ARF6-JIP3/4 regulate endosomal tubules for MT1-MMP exocytosis in cancer invasion.

Invasion of cancer cells into collagen-rich extracellular matrix requires membrane-tethered membrane type 1-matrix metalloproteinase (MT1-MMP) as the key protease for collagen breakdown. Understanding how MT1-MMP is delivered to the surface of tumor cells is essential for cancer cell biology. In this study, we identify ARF6 together with c-Jun NH2-terminal kinase-interacting protein 3 and 4 (JIP3 and JIP4) effectors as critical regulators of this process.

p63/MT1-MMP axis is required for in situ to invasive transition in basal-like breast cancer.

The transition of ductal carcinoma in situ (DCIS) to invasive breast carcinoma requires tumor cells to cross the basement membrane (BM). However, mechanisms underlying BM transmigration are poorly understood. Here, we report that expression of membrane-type 1 (MT1)-matrix metalloproteinase (MMP), a key component of the BM invasion program, increases during breast cancer progression at the in situ to invasive breast carcinoma transition.

Hypoxia-induced nitric oxide release by luminal cells stimulates proliferation and uPA secretion of myoepithelial cells in a bicellular murine mammary tumor.

Introduction: LM38 murine mammary adenocarcinoma model is formed by LM38-LP (myoepithelial and luminal), LM38-HP (luminal) and LM38-D2 (myoepithelial) cell lines. In a previous work, we had shown that LM38-HP and LM38-D2 cell lines are less malignant than the bicellular LM38-LP cell line.

Purpose: To study the role of nitric oxide (NO) as one of the mediators of functional interactions between malignant luminal and myoepithelial cells.

Control of MT1-MMP transport by atypical PKC during breast-cancer progression.

Dissemination of carcinoma cells requires the pericellular degradation of the extracellular matrix, which is mediated by membrane type 1-matrix metalloproteinase (MT1-MMP). In this article, we report a co-up-regulation and colocalization of MT1-MMP and atypical protein kinase C iota (aPKCι) in hormone receptor-negative breast tumors in association with a higher risk of metastasis. Silencing of aPKC in invasive breast-tumor cell lines impaired the delivery of MT1-MMP from late endocytic storage compartments to the surface and inhibited matrix degradation and invasion.

An essential role for decorin in bladder cancer invasiveness.

Muscle-invasive forms of urothelial carcinomas are responsible for most mortality in bladder cancer. Finding new treatments for invasive bladder tumours requires adequate animal models to decipher the mechanisms of progression, in particular the way tumours interact with their microenvironment. Herein, using the murine bladder tumour cell line MB49 and its more aggressive variant MB49-I, we demonstrate that the adaptive immune system efficiently limits progression of MB49, whereas MB49-I has lost tumour antigens and is insensitive to adaptive immune responses.

Role of peroxisome proliferator activated receptor-gamma in bacillus Calmette-Guérin bladder cancer therapy.

Purpose: We evaluated the effects of combined PPARg agonist with bacillus Calmette-Guérin in bladder cancer growth in vitro and in vivo, focusing on the tissue remodeling mechanisms induced by bacillus Calmette-Guérin.

Materials And Methods: PPARs are a superfamily of nuclear receptors that are transcription factors activated by ligands. Activation of PPARg, the γ subtype, causes proliferation inhibition or differentiation of tumor cells.

Inducible nitric oxide synthase and PPARγ are involved in bladder cancer progression.

Purpose: We evaluated the role of inducible nitric oxide synthase and PPARγ as prognostic factors for bladder cancer.

Materials And Methods: Inducible nitric oxide synthase and PPARγ were evaluated by Western blot and immunohistochemistry in a mouse bladder cancer model of nonmuscle invasive and invasive MB49-I tumor cells, and in human bladder cancer samples.

Results: Inducible nitric oxide synthase expression was negative in mouse normal urothelium and higher in invasive than in noninvasive MB49 tumors.

Cytogenetic characterization of the murine bladder cancer model MB49 and the derived invasive line MB49-I.

Bladder cancer is frequently associated with chromosomal abnormalities, and the complexity of karyotypes increases with tumor progression. The murine model MB49 is one of the most widely studied models of bladder cancer. We developed the invasive cell line MB49-I by successive in vivo passages of MB49 primary tumors.

Bacillus Calmette Guerin induces fibroblast activation both directly and through macrophages in a mouse bladder cancer model.

Background: Bacillus Calmette-Guerin (BCG) is the most effective treatment for non-muscle invasive bladder cancer. However, a failure in the initial response or relapse within the first five years of treatment has been observed in 20% of patients. We have previously observed that in vivo administration of an inhibitor of nitric oxide improved the response to BCG of bladder tumor bearing mice.

Novel invasive orthotopic bladder cancer model with high cathepsin B activity resembling human bladder cancer.

Purpose: We developed and characterized an orthotopic invasive bladder tumor model.

Material And Methods: The MB49-I invasive bladder tumor cell line was obtained after 13 consecutive in vivo passages of primary tumor obtained by subcutaneous inoculation of MB49 bladder tumor cells in C57Bl/6J male mice.

Results: MB49-I tumor local invasiveness, tumor weight and spontaneous metastatic capacity were higher than in MB49 tumors.

Cathepsin B is involved in the apoptosis intrinsic pathway induced by Bacillus Calmette-Guérin in transitional cancer cell lines.

Bacillus Calmette-Guérin (BCG) is the most effective treatment for superficial and in situ transitional bladder cancer. Although the complete mechanisms for its effect are not fully understood yet, both immunological and direct effects on tumor cells have been proposed. It has been proposed that apoptotic tumor cells could be better inducers of immunity than necrotic ones.

Bacillus Calmette-Guérin induces the expression of peroxisome proliferator-activated receptor gamma in bladder cancer cells.

Bacillus Calmette-Guérin (BCG) is considered to be one of the most effective treatments for superficial and in situ bladder cancer. The exact mechanism of the antitumor activity of BCG is not completely understood. Peroxisome proliferator-activated receptor gamma (PPARgamma) is a member of the nuclear receptor superfamily of ligand-activated transcription factors that is involved in cell growth and differentiation as well as inflammatory processes.

Inhibition of bacillus Calmette-Guérin-induced nitric oxide in bladder tumor cells may improve BCG treatment.

Bacillus Calmette-Guérin (BCG) is considered to be one of the most effective treatments for superficial and in situ bladder cancer. However, either failure to respond initially or relapse within the first 5 years of treatment has been observed in some patients. As nitric oxide (NO) has been detected in the bladder of BCG-treated patients, we analyzed the role of endogenous NO generated after BCG treatments on human (T24) and murine (MB49 and MBT2) bladder tumor cells in the viability of tumor and immune cells, both in vitro and in vivo.