The effect of cilostazol on the platelet-derived growth factor-beta/beta isoform reduction on venous hyperplasia in an experimental balloon-induced injury model.

BACKGROUND: Intimal hyperplasia is the response to endothelial injury. Platelet-derived growth factor is released early and favors the formation of intimal hyperplasia. Although multiple treatments, from open surgery to endovascular techniques, have been used they remain controversial. There is currently interest in developing pharmacological strategies to address this pathology. Local vascular inflammation induced by vessel barotrauma generates intimal hyperplasia due to mechanical stress over the venous endothelium. Cilostazol is a selective phosphodiesterase type 3 (PDE3) selective inhibitor with a regulatory effect over intimal hyperplasia. The objective was to investigate cilostazol's role in inhibiting smooth muscle cell proliferation due to changes in the expression and release of PDGF-BB isoform and the effect on developing IH using an experimental model of vascular barotrauma (balloon-induced injury model). METHODS: We included 12 New Zealand rabbits. The balloon-induced injury model (BIIM) and experimental group cilostazol (20 mg/kg/day) included 6 rabbits each. Contralateral veins from 6 rabbits used in BIIM model has been taken as control group. We measured and compared the expression of PDGF-BB and the development of IH. A pathologist board chooses a PDGFRα antibody to localized its expression by immunohistochemistry analysis. Subsequently, using an automated immunohistochemical staining machine, the PDGFR expression was evaluated using a Zeiss Primo Star 4 light microscope. RESULTS: The measurement obtained in the intimal layer was: 126.12 µm2 in the CG, 232 µm2 in the BIIM group, and 178 µm2 in the EG. A statistically significant difference was observed. Baseline serum concentrations of PDGF-BB in the BIIM group were 0.22 pg/mL. At 12 h 0.42 pg/mL, and 0.17 pg/mL at seven days. In the experimental group, the basal levels were 0.33 pg/mL. With the use of cilostazol, a lower peak was obtained at 12 h (0.08 pg/mL). This difference was statistically significant. CONCLUSIONS: Cilostazol induced a significant reduction of IH caused by barotrauma in the venous endothelium, which correlates with decrease in the PDGF-BB in serum. This could be attributed to the pharmacologic effect on PDGFR expression.

Examining the Role of Histaminergic, Orexinergic, and Cannabinergic Systems in Redox Regulation in Gastric Adenocarcinoma.

Histaminergic, orexinergic, and cannabinoid systems play a role in both physiologic and oncogenic mechanisms in digestive tissues. These three systems are important mediators of tumor transformation, as they are associated with redox alterations, which are key aspects in oncological disorders. The three systems are known to promote alterations in the gastric epithelium through intracellular signaling pathways, such as oxidative phosphorylation, mitochondrial dysfunction, and increased Akt, which might promote tumorigenesis. Histamine promotes cell transformation through redox-mediated alterations in the cell cycle, DNA repair, and immunological response. The increase in histamine and oxidative stress generates angiogenic and metastatic signals through the VEGF receptor and H2R-cAMP-PKA pathway. Immunosuppression in the presence of histamine and ROS is linked to a decrease in dendritic and myeloid cells in gastric tissue. These effects are counteracted by histamine receptor antagonists, such as cimetidine. Regarding orexins, overexpression of the Orexin 1 Receptor (OX1R) induces tumor regression through the activation of MAPK-dependent caspases and src-tyrosine. OX1R agonists are candidates for the treatment of gastric cancer by stimulating apoptosis and adhesive interactions. Lastly, cannabinoid type 2 (CB2) receptor agonists increase ROS, leading to the activation of apoptotic pathways. In contrast, cannabinoid type 1 (CB1) receptor agonists decrease ROS formation and inflammation in gastric tumors exposed to cisplatin. Overall, the repercussion of ROS modulation through these three systems on tumor activity in gastric cancer depends on intracellular and/or nuclear signals associated with proliferation, metastasis, angiogenesis, and cell death. Here, we review the role of these modulatory systems and redox alterations in gastric cancer.

Characterization of triple negative breast cancer gene expression profiles in Mexican patients.

Triple negative breast cancer (TNBC) is an aggressive type of cancer that accounts for ~23% of breast tumors in Mexico. In an attempt to understand in an improved way the behavior of TNBC, throughout the years, gene expression in these tumors has been studied. Lehman et al identified 6 subtypes of gene expression in TNBC with distinct characteristics. In the present study, it was aimed to assess clinical, pathological and prognostic characteristics of TNBC in a Mexican-based cohort. A total of 55 patients diagnosed with TNBC at Mexico's National Institute of Cancer (INCan) were included. Tumor needle biopsy samples were obtained and subjected to microarray analysis. Patients were thus classified into one of the 6 TNBC molecular subtypes. The prognostic, clinical and pathological information of patients was obtained, and differences across molecular subtypes were sought. Out of the 55 included patients, the following subtypes were identified: 9 basal-like-1, 11 basal-like-2 (BSL2), 16 immunomodulatory (IM), 12 mesenchymal, 6 androgen receptor-like and 1 mesenchymal stem-like. Mean follow-up time was 47.1 months. The IM molecular subtype had the best overall survival (OS) (median OS was not reached). BSL2 had the worst OS (15 months). A complete pathologic response to neoadjuvant chemotherapy was obtained more often in the IM subtype (P=0.032). No significant associations were found between any of the clinical or pathological characteristics and the TNBC molecular subtypes. The results obtained from the present study should be considered when seeking to implement a clinical-molecular model for TNBC patient care, particularly in Hispanic-based populations, as they have been frequently underrepresented in clinical studies assessing TNBC molecular subtypes.

Clinical and pathological characteristics associated with the presence of the IS6110 Mycobacterim tuberculosis transposon in neoplastic cells from non-small cell lung cancer patients.

Lung cancer (LC) and pulmonary tuberculosis (TB) are the deadliest neoplastic and bacterial infectious diseases worldwide, respectively. Clinicians and pathologists have long discussed the co-existence of LC and TB, and several epidemiologic studies have presented evidence indicating that TB could be associated with the development of LC, particularly adenocarcinoma. Nonetheless, this data remains controversial, and the mechanism which could underlie the association remains largely unexplored. Some bioinformatic studies have shown that human cancer biopsies have a very high frequency of bacterial DNA integration; since Mycobacterium Tuberculosis (MTb) is an intracellular pathogen, it could play an active role in the cellular transformation. Our group performed an exploratory study in a cohort of 88 LC patients treated at the Instituto Nacional de Cancelorogía (INCan) of Mexico City to evaluate the presence of MTb DNA in LC tissue specimens. For the first time, our results show the presence of the MTb IS6110 transposon in 40.9% (n = 36/88) of patients with lung adenocarcinomas. Additionally, through in-situ PCR we identified the presence of IS6110 in the nuclei of tumor cells. Furthermore, shotgun sequencing from two samples identified traces of MTb genomes present in tumor tissue, suggesting that similar Mtb strains could be infecting both patients.

Immune Milieu and Genomic Alterations Set the Triple-Negative Breast Cancer Immunomodulatory Subtype Tumor Behavior.

Triple-negative breast cancer (TNBC) is an aggressive and heterogeneous disease. Seven subtypes have been described based on gene expression patterns. Herein, we characterized the tumor biology and clinical behavior of the immunomodulatory (IM) subtype. METHODS: Formalin-fixed paraffin-embedded tumor samples from 68 high-risk (stage III-IV) TNBC patients were analyzed through microarrays, immunohistochemistry, and DNA sequencing. RESULTS: The IM subtype was identified in 24% of TNBC tumor samples and characterized by a higher intratumoral (intT) and stromal (strml) infiltration of FOXP3+ TILs (Treg) compared with non-IM subtypes. Further, PD-L1+ (>1%) expression was significantly higher, as well as CTLA-4+ intT and strml expression in the IM subtype. Differential expression and gene set enrichment analysis identified biological processes associated with the immune system. Pathway analysis revealed enrichment of the ß-catenin signaling pathway. The non-coding analysis led to seven Long Intergenic Non-Protein Coding RNAs (lincRNAs) (6 up-regulated and 1 down-regulated) that were associated with a favorable prognosis in the TNBC-IM subtype. The DNA sequencing highlighted two genes relevant to immune system responses: CTNNB1 (Catenin ß-1) and IDH1. CONCLUSION: the IM subtype showed a distinct immune microenvironment, as well as subtype-specific genomic alterations. Characterizing TNBC at a molecular and transcriptomic level might guide immune-based therapy in this subgroup of patients.

Oleamide Induces Cell Death in Glioblastoma RG2 Cells by a Cannabinoid Receptor-Independent Mechanism.

The endocannabinoid system has been associated with antiproliferative effects in several types of tumors through cannabinoid receptor-mediated cell death mechanisms. Oleamide (ODA) is a CB1/CB2 agonist associated with cell growth and migration by adhesion and/or ionic signals associated with Gap junctions. Antiproliferative mechanisms related to ODA remain unknown. In this work, we evaluated the effects of ODA on cell viability and morphological changes in a rat RG2 glioblastoma cell line and compared these effects with primary astrocyte cultures from 8-day postnatal rats. RG2 and primary astrocyte cultures were treated with ODA at increasing concentrations (25, 50, 100, and 200 µM) for different periods of time (12, 24, and 48 h). Changes in RG2 cell viability and morphology induced by ODA were assessed by viability/mitochondrial activity test and phase contrast microscopy, respectively. The ratios of necrotic and apoptotic cell death, and cell cycle alterations, were evaluated by flow cytometry. The roles of CB1 and CB2 receptors on ODA-induced changes were explored with specific receptor antagonists. ODA (100 µM) induced somatic damage, detachment of somatic bodies, cytoplasmic polarization, and somatic shrinkage in RG2 cells at 24 and 48 h. In contrast, primary astrocytes treated at the same ODA concentrations exhibited cell aggregation but not cell damage. ODA (100 µM) increased apoptotic cell death and cell arrest in the G1 phase at 24 h in the RG2 line. The effects induced by ODA on cell viability of RG2 cells were independent of CB1 and CB2 receptors or changes in intracellular calcium transient. Results of this novel study suggest that ODA exerts specific antiproliferative effects on RG2 glioblastoma cells through unconventional apoptotic mechanisms not involving canonical signals.

Endocannabinoids as Therapeutic Targets.

Most of the drugs of abuse affect the brain by interacting with naturally expressed molecular receptors. Marihuana affects a series of receptors including cannabinoid receptor 1 (CB1R) and CB2R, among others. Endogenous molecules with cannabinoid activity interact with these receptors naturally. Receptors, ligands, synthesizing and degrading enzymes, as well as transporters, have been described. This endocannabinoid system modulates behaviors and physiological processes, i.e. food intake, the sleep-waking cycle, learning and memory, motivation, and pain perception, among others. The rather broad distribution of endocannabinoids in the brain explains the different effects marihuana induces in its users. However, this very same anatomical and physiological distribution makes this system a useful target for therapeutic endeavors. In this review, we briefly discuss the potential of small molecules that target the endocannabinoids as therapeutic tools to improve behaviors and treat illnesses. We believe that under medical supervision, endocannabinoid targets offer new advantages for patients for controlling multiple medical disorders.

Long non-coding RNAs: implications in targeted diagnoses, prognosis, and improved therapeutic strategies in human non- and triple-negative breast cancer.

Triple-negative breast cancer (TNBC) has been clinically difficult to manage because of tumor aggressiveness, cellular and histological heterogeneity, and molecular mechanisms' complexity. All this in turn leads us to evaluate that tumor biological behavior is not yet fully understood. Additionally, the heterogeneity of tumor cells represents a great biomedicine challenge in terms of the complex molecular-genetical-transcriptional and epigenetical-mechanisms, which have not been fully elucidated on human solid tumors. Recently, human breast cancer, but specifically TNBC is under basic and clinical-oncology research in the discovery of new molecular biomarkers and/or therapeutic targets to improve treatment responses, as well as for seeking algorithms for patient stratification, seeking a positive impact in clinical-oncology outcomes and life quality on breast cancer patients. In this sense, important knowledge is emerging regarding several cancer molecular aberrations, including higher genetic mutational rates, LOH, CNV, chromosomal, and epigenetic alterations, as well as transcriptome aberrations in terms of the total gene-coding ribonucleic acids (RNAs), known as mRNAs, as well as non-coding RNA (ncRNA) sequences. In this regard, novel investigation fields have included microRNAs (miRNAs), as well as long ncRNAs (lncRNAs), which have been importantly related and are likely involved in the induction, promotion, progression, and/or clinical therapeutic response trackers of TNBC. Based on this, in general terms according with the five functional archetype classification, the lncRNAs may be involved in the regulation of several molecular mechanisms which include genetic expression, epigenetic, transcriptional, and/or post-transcriptional mechanisms, which are nowadays not totally understood. Here, we have reviewed the main dis-regulated and functionally non- and well-characterized lncRNAs and their likely involvement, from a molecular enrichment and mechanistic point of view, as tumor biomarkers for breast cancer and its specific histological subtype, TNBC. In reference to the abovementioned, it has been described that some lncRNA expression profiles correspond or are associated with the TNBC histological subtype, potentially granting their use for TNBC malignant progression, diagnosis, tumor clinical stage, and likely therapy. Based on this, lncRNAs have been proposed as potential biomarkers which might represent potential predictive tools in the differentiated breast carcinomas versus TNBC malignant disease. Finally, elucidation of the specific or multi-functional archetypal of lncRNAs in breast cancer and TNBC could be fundamental, as these molecular intermediary-regulator "lncRNAs" are widely involved in the genome expression, epigenome regulation, and transcriptional and post-transcriptional tumor biology, which in turn will probably represent a new prospect in clinical and/or therapeutic molecular targets for the oncological management of breast carcinomas in general and also for TNBC patients.

Differential gene expression profiles according to the Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society histopathological classification in lung adenocarcinoma subtypes.

The current lung cancer classification from the Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society has considerably changed the pathologic diagnosis of lung invasive adenocarcinoma, identifying disease subtypes with substantial implications for medical practice, such as clinical, radiological, molecular, and prognostic differences. We analyzed the differences in the genetic expression of adenocarcinoma subtypes according to the new classification. Microarray gene expression analysis was performed on a cohort of 29 adenocarcinoma patients treated at the Instituto Nacional de Cancerología of Mexico from 2008 to 2011. All patients had an available biopsy sample and were classified into 4 different subtypes of adenocarcinoma (2015 World Health Organization classification). Lepidic-predominant adenocarcinoma was the only pattern that exhibited a marked gene expression difference compared with other predominant histologic patterns, revealing genes with significant expression (P < .01). Moreover, we identified 13 genes with specific differential expression in the lepidic-predominant adenocarcinoma that could be used as a gene signature. The lepidic-predominant histologic pattern has a differential gene expression profile compared with all predominant histologic patterns. Additionally, we identified a gene expression signature of 13 genes that have a unique behavior in the lepidic histologic pattern; these 13 genes are candidates for follow-up studies for their potential use as biomarkers or therapeutic targets. Results from this study highlight the importance of the new Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification and exemplify the potential clinical implications of correlating histopathology with exclusive molecular beacons.

Gene-expression profiles in lung adenocarcinomas related to chronic wood smoke or tobacco exposure.

BACKGROUND: Tobacco-smoke is the major etiological factor related to lung cancer. However, other important factor is chronic wood smoke exposure (WSE). Approximately 30 % of lung cancer patients in Mexico have a history of WSE, and present different clinical, pathological and molecular characteristics compared to tobacco related lung cancer, including differences in mutational profiles. There are several molecular alterations identified in WSE associated lung cancer, however most studies have focused on the analysis of changes in several pathogenesis related proteins. METHODS: Our group evaluated gene expression profiles of primary lung adenocarcinoma, from patients with history of WSE or tobacco exposure. Differential expression between these two groups were studied through gene expression microarrays. RESULTS: Results of the gene expression profiling revealed 57 statistically significant genes (p < 0.01). The associated biological functional pathways included: lipid metabolism, biochemistry of small molecules, molecular transport, cell morphology, function and maintenance. A highlight of our analysis is that three of the main functional networks represent 37 differentially expressed genes out of the 57 found. These hubs are related with ubiquitin C, GABA(A) receptor-associated like protein; and the PI3K/AKT and MEK/ERK signaling pathways. CONCLUSION: Our results reflect the intrinsic biology that sustains the development of adenocarcinoma related to WSE and show that there is a different gene expression profile of WSE associated lung adenocarcinoma compared to tobacco exposure, suggesting that they arise through different carcinogenic mechanisms, which may explain the clinical and mutation profile divergences between both lung adenocarcinomas.

Phase II randomized, double-blind, placebo-controlled study of whole-brain irradiation with concomitant chloroquine for brain metastases.

BACKGROUND AND PURPOSE: Chloroquine (CLQ), an antimalarial drug, has a lysosomotropic effect associated with increased radiationsensibility, which is mediated by the leakage of hydrolytic enzymes, increased apoptosis, autophagy and increased oxidative stress in vitro. In this phase II study, we evaluated the efficacy and safety of radiosensibilization using CLQ concomitant with 30 Gray (Gy) of whole-brain irradiation (WBI) to treat patients with brain metastases (BM) from solid tumors. METHODS: Seventy-three eligible patients were randomized. Thirty-nine patients received WBI (30 Gy in 10 fractions over 2 weeks) concomitant with 150 mg of CLQ for 4 weeks (the CLQ arm). Thirty-four patients received the same schedule of WBI concomitant with a placebo for 4 weeks (the control arm). All the patients were evaluated for quality of life (QoL) using the EORTC Quality of Life (QoL) Questionnaire (EORTC QLQ-C30) (Mexican version) before beginning radiotherapy and one month later. RESULTS: The overall response rate (ORR) was 54% for the CLQ arm and 55% for the control arm (p=0.92). The progression-free survival of brain metastases (BMPFS) rates at one year were 83.9% (95% CI 69.4-98.4) for the CLQ arm and 55.1% (95% CI 33.6-77.6) for the control arm. Treatment with CLQ was independently associated with increased BMPFS (RR 0.31,95% CI [0.1-0.9], p=0.046).The only factor that was independently associated with increased overall survival (OS) was the presence of< 4 brain metastases (RR 1.9, 95% CI [1.12-3.3], p=0.017). WBI was associated with improvements in cognitive and emotional function but also with worsened nausea in both patients groups. No differences in QoL or toxicity were found between the study arms. CONCLUSION: Treatment with CLQ plus WBI improved the control of BM (compared with the control arm) with no increase in toxicity; however, CLQ did not improve the RR or OS. A phase III clinical trial is warranted to confirm these findings.

Myosin Va is proteolysed in rat cerebellar granule neurons after excitotoxic injury.

Cerebellar granule neurons when exposed to glutamate die through an excitotoxic mechanism induced by overactivation of glutamate receptors. This kind of cell death is mediated by an overload of intracellular calcium involving calpain activation, a Ca2+ -dependent intracellular cysteine protease, among other intracellular responses. On the other hand, class V myosins are proteins that move cargo along actin filaments and one of its members, myosin Va, is involved in vesicles transport. Here we studied the effect of excitotoxicity on myosin Va in cultured cerebellar granule neurons. Western blot analysis of control cultures shows a band corresponding to myosin Va as well as an 80 kDa band corresponding to its proteolytic product by calpain. When cells are exposed to glutamate (500 microM), kainate (100 microM) or NMDA (150 microM) during 3-24 h, the proteolytic processing of myosin Va is markedly increased. This proteolysis is inhibited by leupeptin (100 microM) and calpain inhibitor I (50 microM). These inhibitors also significantly improve the morphological appearance of the neurons possibly through the preservation of the cytoskeleton integrity. Our results suggest that myosin Va is a target for calpain I during an excitotoxic injury and could lead to a new area of research to address the participation of molecular motors in neurotoxicity.