Morte súbita e angina vasoespástica

Variant angina is defined by chest pain occurring at rest associated with transitory ST segment elevation on ECG, and is caused by a spasm of a coronary artery. Frequently, variant angina is associated with atherosclerotic coronary obstruction and patients with normal coronary arteries are rare. Patients with variant angina and normal coronary arteries have good prognosis, and the development of ventricular arrhythmias or sudden death is rare. The authors present two cases of sudden cardiac death in patients with variant angina and normal coronary arteries

Activation of the orphan receptor GPR55 by lysophosphatidylinositol promotes metastasis in triple-negative breast cancer

The orphan G protein-coupled receptor GPR55 has been directly or indirectly related to basic alterations that drive malignant growth: uncontrolled cancer cell proliferation, sustained angiogenesis, and cancer cell adhesion and migration. However, little is known about the involvement of this receptor in metastasis. Here, we show that elevated GPR55 expression in human tumors is associated with the aggressive basal/triple-negative breast cancer population, higher probability to develop metastases, and therefore poor patient prognosis. Activation of GPR55 by its proposed endogenous ligand lysophosphatidylinositol confers pro-invasive features on breast cancer cells both in vitro and in vivo. Specifically, this effect is elicited by coupling to Gq/11 heterotrimeric proteins and the subsequent activation, through ERK, of the transcription factor ETV4/PEA3. Together, these data show that GPR55 promotes breast cancer metastasis, and supports the notion that this orphan receptor may constitute a new therapeutic target and potential biomarker in the highly aggressive triple-negative subtypeThis work was supported by grants from Spanish Ministry of Economy and Competitiveness [PI11/00295 to CS, PI14/01101 to CS and EP-G, SAF2013-46183-R to MQ, and SAF2014-54705-R to MV-M, supported with European Regional Development (FEDER) funds] and Madrid Regional Government (S2010/BMD-2308 to MG, and 2010/BMD-2359 to MQ). EPG was a recipient of a Postdoctoral Research Contract from Fundación Científica Asociación Española Contra el Cáncer and a Federation of the Societies of Biochemistry and Molecular Biology (FEBS) Short-term Fellowship. SB-B and SC-L are recipients of a Formación de Profesorado Universitario (FPU) fellowship and a Ramón y Cajal research contract, respectively, from the Spanish Ministry of Economy and Competitivenes

Angiotensin II Facilitates Breast Cancer Cell Migration and Metastasis

Breast cancer metastasis is a leading cause of death by malignancy in women worldwide. Efforts are being made to further characterize the rate-limiting steps of cancer metastasis, i.e. extravasation of circulating tumor cells and colonization of secondary organs. In this study, we investigated whether angiotensin II, a major vasoactive peptide both produced locally and released in the bloodstream, may trigger activating signals that contribute to cancer cell extravasation and metastasis. We used an experimental in vivo model of cancer metastasis in which bioluminescent breast tumor cells (D3H2LN) were injected intra-cardiacally into nude mice in order to recapitulate the late and essential steps of metastatic dissemination. Real-time intravital imaging studies revealed that angiotensin II accelerates the formation of metastatic foci at secondary sites. Pre-treatment of cancer cells with the peptide increases the number of mice with metastases, as well as the number and size of metastases per mouse. In vitro, angiotensin II contributes to each sequential step of cancer metastasis by promoting cancer cell adhesion to endothelial cells, trans-endothelial migration and tumor cell migration across extracellular matrix. At the molecular level, a total of 102 genes differentially expressed following angiotensin II pre-treatment were identified by comparative DNA microarray. Angiotensin II regulates two groups of connected genes related to its precursor angiotensinogen. Among those, up-regulated MMP2/MMP9 and ICAM1 stand at the crossroad of a network of genes involved in cell adhesion, migration and invasion. Our data suggest that targeting angiotensin II production or action may represent a valuable therapeutic option to prevent metastatic progression of invasive breast tumors

Resveratrol and quercetin cooperate to induce senescence-like growth arrest in C6 rat glioma cells

Glioma is the most frequent and malignant primary human brain tumor with dismal prognosis despite multimodal therapy. Resveratrol and quercetin, two structurally related and naturally occurring polyphenols, are proposed to have anticancer effects. We report here that resveratrol and quercetin decreased the cell number in four glioma cell lines but not in rat astrocytes. Low doses of resveratrol (10 mu M) or quercetin (25 mu M) separately had no effect on apoptosis induction, but had a strong effect on caspase 3/7 activation when administered together. Western blot analyses showed that resveratrol (10 mu M) and quercetin (25 mu M) caused a reduction in phosphorylation of Akt, but this reduction was not sufficient by itself to mediate the effects of these polyphenols. Most important, resveratrol and quercetin chronically administered presented a strong synergism in inducing senescence-like growth arrest. These results suggest that the combination of polyphenols can potentialize their antitumoral activity, thereby reducing the therapeutic concentration needed for glioma treatment. (Cancer Sci 2009; 100: 1655-1662).CNPqFAPERGSPROPESQ/UFRG

Participation of kallikrein-kinin system in different pathologies

The general description of kinins refers to these peptides as molecules involved in vascular tone regulation and inflammation. Nevertheless, in the last years a series of, evidences has shown that local hormonal systems, such as the kallikrein-kinin system, may be differently regulated and are of pivotal importance to pathophysiological control. The combined interpretations of many recent studies allow us to conclude that the kallikrein-kinin system plays broader and richer roles than those classically described until recently. In this review, we report findings concerning the participation of the kallikrein-kinin system in inflammation, cancer, and in pathologies related to cardiovascular, renal and central nervous systems. (c) 2007 Elsevier B.V. All rights reserved

SDF-1/CXCL12 induces directional cell migration and spontaneous metastasis via a CXCR4/Gαi/mTORC1 axis.

Multiple human malignancies rely on C-X-C motif chemokine receptor type 4 (CXCR4) and its ligand, SDF-1/CXCL12 (stroma cell-derived factor 1/C-X-C motif chemokine 12), to metastasize. CXCR4 inhibitors promote the mobilization of bone marrow stem cells, limiting their clinical application for metastasis prevention. We investigated the CXCR4-initiated signaling circuitry to identify new potential therapeutic targets. We used HeLa human cancer cells expressing high levels of CXCR4 endogenously. We found that CXCL12 promotes their migration in Boyden chamber assays and single cell tracking. CXCL12 activated mTOR (mechanistic target of rapamycin) potently in a pertussis-sensitive fashion. Inhibition of mTOR complex 1 (mTORC1) by rapamycin [drug concentration causing 50% inhibition (IC50) = 5 nM] and mTORC1/mTORC2 by Torin2 (IC50 = 6 nM), or by knocking down key mTORC1/2 components, Raptor and Rictor, respectively, decreased directional cell migration toward CXCL12. We developed a CXCR4-mediated spontaneous metastasis model by implanting HeLa cells in the tongue of SCID-NOD mice, in which 80% of the animals develop lymph node metastasis. It is surprising that mTORC1 disruption by Raptor knockdown was sufficient to reduce tumor growth by 60% and spontaneous metastasis by 72%, which were nearly abolished by rapamycin. In contrast, disrupting mTORC2 had no effect in tumor growth or metastasis compared with control short hairpin RNAs. These data suggest that mTORC1 may represent a suitable therapeutic target in human malignancies using CXCR4 for their metastatic spread.

AngII increases breast cancer cell adhesion and migration.

<p>(<b>A</b>). MDA-MB-231 breast cancer cell adhesion to HCMEC/D3 endothelial cells monolayer following exposure of cancer cells to AngII (100 nM) for 24 hrs. Results are means +/− SEM of 7 independent experiments performed in quadruplicate, and expressed as fold increase of untreated cells (control, Ctrl). *p<0.05. (<b>B, C</b>). Boyden chamber assays of tumor cell migration across 8 µm-pore filters either non coated (B) or coated with matrigel to mimic cell invasion (C). Results are means +/− SEM of 3 separate experiments performed in triplicate, and expressed as fold increase of control. *p<0.05. (<b>D, E</b>). Wound healing assay. Results are from 2 independent experiments performed in quintuplicate, and expressed as fold increase of wound closure at time 16 hrs (T16) compared to control (vehicle-treated cells). *p<0.05. (E). Representative pictures of wounds from control and AngII-treated cells (100 nM, 24 hrs) at T0 and T16. Magnification, 100x. (<b>F</b>). Trans-endothelial migration. Results are mean +/− SEM of 3 independent experiments performed in triplicate, and expressed as fold increase of control. *p<0.05.</p

AngII increases the time-course, incidence and number of metastases in an experimental model <i>in vivo</i>.

<p>(<b>A</b>). Percentage of mice showing at least one detectable metastasis over time after intracardiac injection of D3H2LN cells treated with AngII (red dotted line, n = 14) or vehicle (black line, n = 15). (<b>B</b>). Number of metastases per mouse at indicated days. Results are mean +/− SEM of 15 control (white bar) and 14 AngII-treated (black bar) groups. (<b>C</b>). Number of photons/s per mouse at indicated days. Results are expressed as in B. (<b>D</b>). Histological analysis of metastases developing at the brain (left panel), the lung (middle panel) and the bone (right panel), obtained from 3 µm sections of formalin-fixed, paraffin-embedded tissue blocks stained with hematoxylin/eosin. Arrows indicate tumor cells. Magnification, 200x. (<b>E</b>). Representative pictures of 5 mice taken at day 9 after injection of control cells (upper panel) or AngII-treated cells (lower panel). * p<0.05, ** p<0.01.</p