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E.R. Parra



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    P1.20 - Poster Session 1 - Early Detection and Screening (ID 172)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Imaging, Staging & Screening
    • Presentations: 1
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      P1.20-009 - New potential marker for the diagnosis of lung cancer: Hyaluronan. (ID 3087)

      09:30 - 09:30  |  Author(s): E.R. Parra

      • Abstract

      Background
      HA concentration is elevated in several cancers, but there is no data regarding its concentration in the sputum of lung cancer patients. In this study, we examined the HA concentrations in tissue and sputum samples and its impact on the screening and diagnosis of lung cancer patients.

      Methods
      Hyaluronic Acid (HA) was examined in lung cancer tissue of 14 patients through immunohistochemistry using a HA-probe. The analysis was performed using ImageProPlus 7.0. The HA concentration in sputum samples of 90 lung cancer patients, 25 COPD patients and 15 healthy controls was also analyzed. All the patients and healthy controls selected underwent a sputum induction. Sputum samples were incubated with urea 7M at 60[o]C and afterwards incubated with a proteolytic enzyme. The levels of HA were measured by a noncompetitive ELISA-like fluorometric assay.

      Results
      It was observed a different expression pattern of HA in squamous cell carcinomas vs. adenocarcinomas specimens (p<0.05). In sputum, a significant different concentration pattern of HA was found among lung cancer, COPD and healthy individuals (p<0.001; Fig1A). Equally significant was the difference between HA in the sputum from lung cancer and healthy volunteers (p<0.001), as well as lung cancer and COPD patients (p=0.002). ROC curve between lung cancer and healthy volunteers furnished an area of 0.821 (0.727–0.915). Assuming a cut off value of 31,44ng/mg, the specificity was 100% and the sensitivity was 51% (Fig1B). ROC curve to distinguish COPD patients from lung cancer patients showed an area of 0.698 (0.600-0.797) and the cut off value of 48.3ng/mg presented 100% of specificity and 33% of sensitivity (Fig1C). Figure 1

      Conclusion
      The results presented suggest a promising role of HA in the developing and progression of lung cancer and its concentration in the sputum as a novel diagnostic marker for differentiating normal from lung cancer patients.

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    P2.01 - Poster Session 2 - Cancer Biology (ID 145)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Biology
    • Presentations: 1
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      P2.01-012 - Pequi fruit (Caryocar brasiliense Camb) protects against oxidative stress induced by urethane in a experimental model of lung cancer. (ID 1479)

      09:30 - 09:30  |  Author(s): E.R. Parra

      • Abstract

      Background
      Pequi (Caryocar brasiliense Camb) is a Brazilian fruit that has high concentrations of antioxidants, such as vitamin C and E, carotenoids, phenolic compounds and essential oils. Consumption of foods high in antioxidants, particularly carotenoids and phenolic compounds have been associated in the prevention of oxidative damage caused by reactive species (ROS), including DNA damage, and can reduce the risk of cancer, atherosclerosis and other degenerative diseases. The aim of this study was to estimate the antioxidant enzyme activity of catalase, superoxide dismutase and glutathione peroxidase and to evaluate the antioxidant activity of the pequi oil, measuring lipid peroxidation, DNA damage and nitric oxid synthases expression.

      Methods
      The study was performed in 40 male BALB/c mices: 35 animals were submitted to two doses of 1,5g/kg intraperitoneal of urethane (U=5), 10 of these mices received by gavage 15μL of pequi pulp oil (U+O), 10 animals received by gavage 15μL of ethanolic extract of pequi pulp (U+E=10) and the other 10 animals received by gavage 3μg/kg of betacarotene (U+B). 5 mices didn’t receive the urethane doses neither the gavage (C=5). After 60 days, the groups were sacrificed. The enzymatic antioxidant defense was measured by biochemical test. The antioxidant activity of pequi oil was evaluated in the lung tissues by the biochemical TBARS test (Thiobarbituric acid-reactive substances) and the DNA damage by the comet test method. Nitric Synthase expression was analyzed by imunohistochemestry.

      Results
      The lung parenchyma from the Urethane groups that received and didn’t receive gavage, showed neoplasic formations induced by the chemical carcinogenesis in contrast with control group (C). The results of the TBARS test showed a significant decreased of the lipid peroxidation in the groups that were treated by gavage (U+O)(U+E)(U+B), when compared with Urethane group (U) (p<0,05). In the same way, the image analysis of the comet assay showed a statistical significant decreased of the DNA damage cells in the groups that received treatment by gavage (U+O)(U+E)(U+B) when compared with urethane group (p<0.001). The nitric oxid synthases expression was higher in the urethane group (U), but showed a significant decrease in groups that received the gavage (p<0,05). The catalase, glutathione peroxidase and superoxide dismutase test, as well as the ratio between then, didn’t show a significant difference.

      Conclusion
      We conclude that because of its composition, high in antioxidants, pequi fruit is efficient to diminish the oxidative stress status (DNA damage and lipid peroxidation) and the nitric oxid synthases expression in chemical carcinogenesis induced by urethane. Our results also suggest that the antioxidant enzyme defense are not envolved in this process, suggesting that antioxidants present in pequi fruit may have a greater impact in lung cancer treatment.