Omega-6 Polyunsaturated Fatty Acids Enhance Tumor Aggressiveness in Experimental Lung Cancer Model: Important Role of Oxylipins.

Lung cancer is currently the leading cause of cancer death worldwide; it is often diagnosed at an advanced stage and bears poor prognosis. It has been shown that diet is an important environmental factor that contributes to the risk and mortality of several types of cancers. Intake of ω-3 and ω-6 PUFAs plays an important role in cancer risk and progression. Current Western populations have high consumption of ω-6 PUFAs with a ratio of ω-6/ω-3 PUFAs at 15:1 to 16.7:1 This high consumption of ω-6 PUFAs is related to increased cancer risk and progression. However, whether a diet rich in ω-6 PUFAs can contribute to tumor aggressiveness has not been well investigated. We used a murine model of pulmonary squamous cell carcinoma to study the aggressiveness of tumors in mice fed with a diet rich in ω-6 PUFAs and its relationship with oxylipins. Our results shown that the mice fed a diet rich in ω-6 showed a marked increase in proliferation, angiogenesis and pro-inflammatory markers and decreased expression of pro-apoptotic proteins in their tumors. Oxylipin profiling revealed an upregulation of various pro-tumoral oxylipins including PGs, HETEs, DiHETrEs and HODEs. These results demonstrate for the first time that high intake of ω-6 PUFAs in the diet enhances the malignancy of tumor cells by histological changes on tumor dedifferentiation and increases cell proliferation, angiogenesis, pro-inflammatory oxylipins and molecular aggressiveness targets such as NF-κB p65, YY1, COX-2 and TGF-ß.

Transcriptional Regulation of Yin-Yang 1 Expression through the Hypoxia Inducible Factor-1 in Pediatric Acute Lymphoblastic Leukemia.

Yin-Yang transcription factor 1 (YY1) is involved in tumor progression, metastasis and has been shown to be elevated in different cancers, including leukemia. The regulatory mechanism underlying YY1 expression in leukemia is still not understood. Bioinformatics analysis reveal three Hypoxia-inducible factor 1-alpha (HIF-1α) putative binding sites in the YY1 promoter region. The regulation of YY1 by HIF-1α in leukemia was analyzed. Mutation of the putative YY1 binding sites in a reporter system containing the HIF-1α promoter region and CHIP analysis confirmed that these sites are important for YY1 regulation. Leukemia cell lines showed that both proteins HIF-1α and YY1 are co-expressed under hypoxia. In addition, the expression of mRNA of YY1 was increased after 3 h of hypoxia conditions and affect several target genes expression. In contrast, chemical inhibition of HIF-1α induces downregulation of YY1 and sensitizes cells to chemotherapeutic drugs. The clinical implications of HIF-1α in the regulation of YY1 were investigated by evaluation of expression of HIF-1α and YY1 in 108 peripheral blood samples and by RT-PCR in 46 bone marrow samples of patients with pediatric acute lymphoblastic leukemia (ALL). We found that the expression of HIF-1α positively correlates with YY1 expression in those patients. This is consistent with bioinformatic analyses of several databases. Our findings demonstrate for the first time that YY1 can be transcriptionally regulated by HIF-1α, and a correlation between HIF-1α expression and YY1 was found in ALL clinical samples. Hence, HIF-1α and YY1 may be possible therapeutic target and/or biomarkers of ALL.

High expression of Myosin 1g in pediatric acute lymphoblastic leukemia.

Acute Lymphoblastic Leukemia (ALL) is the most frequent cancer in pediatric population. Although the treatment has improved and almost 85% of the children are cured about 20% suffer relapse, therefore finding molecules that participate in the pathogenesis of the disease for the identification of relapse and patients at risk is an urgent unmet need. Class I myosins are molecular motors involved in membrane tension, endocytosis, phagocytosis and cell migration and recently they have been shown important for development and aggressiveness of diverse cancer types, however Myo1g an hematopoietic specific myosin has not been studied in cancer so far. We evaluated the expression of Myo1g by qRT-PCR, Immunocytochemistry and Immunofluorescence in a cohort of 133 ALL patients and correlated the expression at diagnosis and after treatment with clinical features and treatment outcomes. We found high expression levels of Myo1g in Peripheral Blood Mononuclear Cells (PBMCs) from patients with ALL at diagnosis and those levels decreased after complete remission; furthermore, we found an increase in Myo1g expression on patients with 9:22 translocation and those who relapse. This study show that Myo1g is over expressed in ALL and that may participate in the pathogenesis of the disease specially in high-risk patients.

Expression of YY1 in pro-B and T phenotypes correlation with poor survival in pediatric acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer, constituting 80% of all acute leukemias in minors. Despite the increase in the success of therapies, disease-free survival is over 80% in most cases. For the remaining 20% of patients, new strategies are needed to allow us to know and select those at greatest risk of relapse. We evaluated by immunohistochemistry the expression of the transcription factor YY1 and found that it is overexpressed in peripheral blood leukemia cells of pediatric patients with ALL with Pro-B and T phenotype compared to control samples. Over expression of YY1 was associated with a significantly lower chance of survival. We also evaluated by RT-PCR in bone marrow samples from ALL pediatric patients the association of YY1 expression with the percentage of blasts. High levels of YY1 were present in samples with higher percent of blasts in these patients. In addition, ALL pediatric patients with a poor response to therapy had higher levels at the nuclear level of YY1 than those who responded well to chemotherapy. In conclusion, our data suggest that YY1 could serve in pediatric ALL as markers of evolution and response for this disease, mainly in patients with pro-B and T immunophenotype. It is also suggested that YY1 is implicated in the expanse of blast in these patients.

A Novel Therapeutic Induces DEPTOR Degradation in Multiple Myeloma Cells with Resulting Tumor Cytotoxicity.

Prior work indicates DEPTOR expression in multiple myeloma cells could be a therapeutic target. DEPTOR binds to mTOR via its PDZ domain and inhibits mTOR kinase activity. We previously identified a drug, which prevented mTOR-DEPTOR binding (NSC126405) and induced multiple myeloma cytotoxicity. We now report on a related therapeutic, drug 3g, which induces proteasomal degradation of DEPTOR. DEPTOR degradation followed drug 3g binding to its PDZ domain and was not due to caspase activation or enhanced mTOR phosphorylation of DEPTOR. Drug 3g enhanced mTOR activity, and engaged the IRS-1/PI3K/AKT feedback loop with reduced phosphorylation of AKT on T308. Activation of TORC1, in part, mediated multiple myeloma cytotoxicity. Drug 3g was more effective than NSC126405 in preventing binding of recombinant DEPTOR to mTOR, preventing binding of DEPTOR to mTOR inside multiple myeloma cells, in activating mTOR and inducing apoptosis in multiple myeloma cells. In vivo, drug 3g injected daily abrogated DEPTOR expression in xenograft tumors and induced an antitumor effect although modest weight loss was seen. Every-other-day treatment, however, was equally effective without weight loss. Drug 3g also reduced DEPTOR expression in normal tissues. Although no potential toxicity was identified in hematopoietic or hepatic function, moderate cardiac enlargement and glomerular mesangial hypertrophy was seen. DEPTOR protected multiple myeloma cells against bortezomib suggesting anti-DEPTOR drugs could synergize with proteasome inhibitors (PI). Indeed, combinations of drug NSC126405 + bortezomib were synergistic. In contrast, drug 3g was not and was even antagonistic. This antagonism was probably due to prevention of proteasomal DEPTOR degradation.

Dual role of hypoxia-inducible factor 1 α in experimental pulmonary tuberculosis: its implication as a new therapeutic target.

AIM: Investigate the role of hypoxia-inducible factor-1α (HIF-1α) in pulmonary tuberculosis (TB). METHODS & RESULTS: A model of progressive pulmonary TB in BALB/c mice, immunohistochemistry and digital pathology were used. High HIF-1α expression was observed during early TB in activated macrophages. During late TB, even higher HIF-1α expression was observed in foamy macrophages, which are resistant to apoptosis. Blocking HIF-1α during early infection with 2-methoxyestradiol worsened the disease, while during late TB, it induced macrophage apoptosis and decreased bacillary loads. CONCLUSION: HIF-1α has a dual role in experimental TB. This finding could have therapeutic implications because combined treatment with 2-methoxyestradiol and antibiotics appeared to eliminate mycobacteria more efficiently than conventional chemotherapy during advanced disease.

Role of Yin Yang-1 (YY1) in the transcription regulation of the multi-drug resistance (MDR1) gene.

Resistance to chemotherapy hinders the successful treatment of acute lymphoblastic leukemia (ALL). The multi-drug resistance-1 (MDR1/ABCB1) gene encodes P-glycoprotein (P-gp), which plays an important role in chemoresistance; however, its transcriptional regulation remains unclear. We investigated the role of YY1 in the regulation of MDR1 and its relation to ALL outcomes. Analysis of the MDR1 promoter revealed four putative YY1-binding sites, which we analyzed using a reporter system and ChIP analysis. YY1 silencing resulted in the inhibition of MDR1 expression and function. The clinical roles of YY1 and MDR1 expression were evaluated in children with ALL. Expression of both proteins was increased in ALL patients compared to controls. We identified a positive correlation between YY1 and MDR1 expression. High levels of YY1 were associated with decreased overall survival. Our results demonstrated that YY1 regulates the transcription of MDR1. Therefore, YY1 may serve as a useful prognostic and/or therapeutic target.

[Corrigendum] Death receptor 5 expression is inversely correlated with prostate cancer progression.

During the preparation of the figures in the above article, the authors inadvertently duplicated in Fig. 1B, a and b (high and low magnification images) the images that had already appeared as Figs. 5A, a and c (high and low magnification images), respectively, of the following paper: Huerta-Yepez S, Baritaki S, Baay-Guzman G, Hernandez-Luna MA, Hernandez-Cueto A, Vega MI and Bonavida B: Contribution of either YY1 or BclXL-induced inhibition by the NO-donor DETANONOate in the reversal of drug resistance, both in vitro and in vivo. Nitric Oxide 29: 17-24, 2013. The revised version of Fig. 1 containing the corrected data for Fig. 1B, a and b (high and low magnification images; the YY1 data) is shown opposite protein expression. All those authors whom the corresponding author was able to contact have agreed to this Corrigendum. The authors regret this error, and apologize for any confusion that it may have caused. [the original article was published in the Molecular Medicine Reports 10: 2279-2286, 2014; DOI: 10.3892/mmr.2014.2504 ].

Inhibition of tumor progression during allergic airway inflammation in a murine model: significant role of TGF-ß.

INTRODUCTION: TGF-ß is an important mediator of pulmonary allergic inflammation, and it has been recently reported to be a potential inhibitor of lung tumor progression. The correlation between cancer and allergic inflammatory diseases remains controversial. Thus, the aim of the present study was to evaluate the effects of pulmonary allergic inflammation and in particular the role of TGF-ß on cancer progression. METHODS: Cancer cells were implanted in a BALB/c mice model of allergic airway inflammation, and tumor growth was measured. Apoptosis was evaluated by TUNEL assay, and TGF-ß was measured by ELISA. Expression of proliferating cell nuclear antigen, TGF-ß, TGF-ß receptors I and II, phospho-Smad2 and phospho-Smad4 was evaluated by immunohistochemistry and quantified using digital pathology. The effect of a TGF-ß activity inhibitor and recombinant TGF-ß on tumor growth was analyzed. The effect of exogenous TGF-ß on cell proliferation and apoptosis was evaluated in vitro. RESULTS: Mice with allergic airway inflammation exhibited decreased tumor volumes due to cell proliferation inhibition and increased apoptosis. TGF-ß was increased in the sera and tumor tissues of allergic mice. TGF-ß activity inhibition increased tumor progression in allergic mice by enhancing proliferation and decreasing apoptosis of tumor cells. The administration of TGF-ß resulted in reduced tumor growth. CONCLUSION: This study is the first to establish an inverse relationship between allergic airway inflammation and tumor progression. This effect appears to be mediated by TGF-ß, which is overexpressed in tumor cells during pulmonary allergic inflammation. This study indicates that TGF-ß is a potential target for antitumor therapy.

Salmonella enterica: un aliado en la terapia contra el cáncer / Salmonella enterica: an ally in the therapy of cancer

Salmonella enterica es una especie de bacterias anaeróbicas facultativas que han sido empleadas con gran éxito como vector bacteriano vivo atenuado con fines vacunales. Recientemente se ha documentado que S. enterica tiene propiedades importantes para ser considerada como agente terapéutico contra el cáncer. Estudios preclínicos y clínicos han demostrado que S. enterica coloniza tumores sólidos, semisólidos y metástasis, además de que contribuye a disminuir la resistencia a los tratamientos. En esta revisión se aborda la capacidad de S. enterica atenuada para eliminar células tumorales y su empleo como vector bacteriano vivo acarreador de moléculas heterólogas contra el cáncer.

Salmonella enterica, a species of facultative anaerobic bacteria, has demonstrated success as a live-attenuated bacterial vector for vaccination. S. enterica has also demonstrated promise as a therapeutic agent against cancer. Pre-clinical and clinical trials have shown that S. enterica is localized in both solid and semi-solid tumors as well as in metastatic tumors. Moreover, S. enterica reduces resistance to treatment with other agents. In this review we present the novel therapeutic anti-cancer approaches that use S. enterica both for its ability as a delivery system for heterologous moieties against cancer and for its direct anti-cancer properties.

[Salmonella enterica: an ally in the therapy of cancer]. / Salmonella enterica: un aliado en la terapia contra el cáncer.

Salmonella enterica, a species of facultative anaerobic bacteria, has demonstrated success as a live-attenuated bacterial vector for vaccination. S. enterica has also demonstrated promise as a therapeutic agent against cancer. Pre-clinical and clinical trials have shown that S. enterica is localized in both solid and semi-solid tumors as well as in metastatic tumors. Moreover, S. enterica reduces resistance to treatment with other agents. In this review we present the novel therapeutic anti-cancer approaches that use S. enterica both for its ability as a delivery system for heterologous moieties against cancer and for its direct anti-cancer properties.

Death receptor 5 expression is inversely correlated with prostate cancer progression.

Prostate carcinoma (PCa) is one of the most common cancers in men. Prostate-specific antigen (PSA) has been widely used to predict the outcome of PCa and screening with PSA has resulted in a decline in mortality. However, PSA is not an optimal prognostic tool as its sensitivity may be too low to reduce morbidity and mortality. Consequently, there is a demand for additional robust biomarkers for prostate cancer. Death receptor 5 (DR5) has been implicated in the prognosis of several cancers and it has been previously shown that it is negatively regulated by Yin Yang 1 (YY1) in prostate cancer cell lines. The present study investigated the clinical significance of DR5 expression in a prostate cancer patient cohort and its correlation with YY1 expression. Immunohistochemical analysis of protein expression distribution was performed using tissue microarray constructs from 54 primary PCa and 39 prostatic intraepithelial neoplasia (PIN) specimens. DR5 expression was dramatically reduced as a function of higher tumor grade. By contrast, YY1 expression was elevated in PCa tumors as compared with that in PIN, and was increased with higher tumor grade. DR5 had an inverse correlation with YY1 expression. Bioinformatic analyses corroborated these data. The present findings suggested that DR5 and YY1 expression levels may serve as progression biomarkers for prostate cancer.