Inhibition of Notch and HIF enhances the antitumor effect of radiation in Notch expressing lung cancer

Background: The Notch receptor plays an important role in various cell fate decisions during development and in cancer. We have previously reported that Notch3 is upregulated by radiation in non-small cell lung cancer (NSCLC) cell lines and that the Notch pathway inhibitor γ secretase inhibitor GSI (gamma-secretase inhibitor), when combined with radiation therapy, significantly suppressed the growth of lung cancer cells. However, little is known about the mechanism of Notch upregulation induced by radiation. Based on reports of Notch expression being activated through the hypoxia inducible factor 1 (HIF-1) under hypoxic conditions, we hypothesized that HIF-1 would be involved in radiation-induced Notch activation in NSCLC. Methods: Changes in HIF-1 and Notch expression in two Notch expressing NSCLC cells line after radiation treatment were examined using Western blotting. Notch expression was evaluated after the suppression of HIF-1α by small interfering RNA. The cytotoxic effect of YC-1, a HIF inhibitor, GSI and radiation was examined using the MTT assay in vitro and the xenograft model. Result: We found radiation-induced expression of HIF-1α protein at 2-6 h after treatment and upregulated expression of Notch3 protein at 24 h after treatment under hypoxic conditions. Specific suppression of HIF-1α expression downregulated the radiation-induced Notch3 activation, suggesting that the Notch pathway is activated though HIF-1α after radiation. An antitumor effect of YC-1 was evident under hypoxic conditions only when there was simultaneous radiation treatment. GSI and YC-1 had a synergistic antitumor effect in vitro, and the combination of GSI and YC-1 showed the greatest radiosensitivity in vivo. Conclusion: Radiation-induced upregulation of the Notch pathway and HIF-1α protein may be potential therapeutic targets for more effective radiation therapy

Expression of Bim, Noxa, and Puma in non-small cell lung cancer

Background: The BH3-only members of the Bcl-2 protein family have been proposed to play a key role in the control of apoptosis and in the initiation of the apoptotic pathways. In this study, we evaluated the expression of Bim, Noxa, and Puma in non-small cell lung cancer (NSCLC). Methods: A total of 135 surgically resected NSCLCs were immunohistochemically assessed for Bim, Noxa, and Puma expression. The immunoscores were determined, and then its correlation with either the clinicopathological variables or the survival outcomes were analyzed. Results: Immunohistochemical reactivity for Bim, Noxa, and Puma was detected in the cytoplasm of the tumor cells. Bim expression was associated with several clinicopathological factors, including sex (p < 0.001), smoking habit (p = 0.03), pathological histology (p = 0.001), pathological T stage (p = 0.03), pathological disease stage (p = 0.02), and differentiation of tumor (p < 0.001). Multivariate logistic regression analysis showed a significant correlation between low Bim expression and squamous cell carcinoma (p = 0.04), in addition to a correlation between high Bim expression and well differentiated tumors (p = 0.02). Analysis of cellular biological expression demonstrated a link between low Bim expression and high Ki67. While Noxa expression was also shown to be correlated with both smoking habit (p = 0.02) and the pathological histology (p = 0.03), there was no strong association observed between the expression and the clinical features when they were examined by a multivariate logistic regression analysis. No correlations were noted between Puma expression and any of the variables. Our analyses also indicated that the expression levels of the BH3-only proteins were not pertinent to the survival outcome. Conclusions: The current analyses demonstrated that Bim expression in the NSCLCs was associated with both squamous cell carcinoma histology and tumor proliferation

Combining transbronchial biopsy using endobronchial ultrasonography with a guide sheath and positron emission tomography for the diagnosis of small peripheral pulmonary lesions

To evaluate the combination of transbronchial biopsy (TBB) using endobronchial ultrasonography with a guide sheath (EBUS-GS) and positron emission tomography with fluorodeoxyglucose (FDG-PET) for the diagnosis of small peripheral pulmonary lesions (PPLs) 20 mm and ≤30 mm and for malignant lesions. Combination of TBB using EBUS-GS and FDG-PET is useful for the diagnosis of small PPLs

Expression of Bim, Noxa, and Puma in non-small cell lung cancer

Abstract Background The BH3-only members of the Bcl-2 protein family have been proposed to play a key role in the control of apoptosis and in the initiation of the apoptotic pathways. In this study, we evaluated the expression of Bim, Noxa, and Puma in non-small cell lung cancer (NSCLC). Methods A total of 135 surgically resected NSCLCs were immunohistochemically assessed for Bim, Noxa, and Puma expression. The immunoscores were determined, and then its correlation with either the clinicopathological variables or the survival outcomes were analyzed. Results Immunohistochemical reactivity for Bim, Noxa, and Puma was detected in the cytoplasm of the tumor cells. Bim expression was associated with several clinicopathological factors, including sex (p  Conclusions The current analyses demonstrated that Bim expression in the NSCLCs was associated with both squamous cell carcinoma histology and tumor proliferation.</p