Cesar E. Ochoa

Nontypeable Haemophilus influenzae in chronic obstructive pulmonary disease and lung cancer.

Chronic obstructive pulmonary disease (COPD) is predicted to become the third leading cause of death in the world by 2020. It is characterized by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lungs to noxious particles and gases, most commonly cigarette smoke. Among smokers with COPD, even following withdrawal of cigarette smoke, inflammation persists and lung function continues to deteriorate. One possible explanation is that bacterial colonization of smoke-damaged airways, most commonly with nontypeable Haemophilus influenzae (NTHi), perpetuates airway injury and inflammation. Furthermore, COPD has also been identified as an independent risk factor for lung cancer irrespective of concomitant cigarette smoke exposure. In this article, we review the role of NTHi in airway inflammation that may lead to COPD progression and lung cancer promotion.

Interleukin 6, but Not T Helper 2 Cytokines, Promotes Lung Carcinogenesis

Several epidemiologic studies have found that smokers with chronic obstructive pulmonary disease (COPD), an inflammatory disease of the lung, have an increased risk of lung cancer compared with smokers without COPD. We have shown a causal role for COPD-like airway inflammation in lung cancer promotion in the CCSPCre/LSL-K-rasG12D mouse model (CC-LR). In contrast, existing epidemiologic data do not suggest any definite association between allergic airway inflammation and lung cancer. To test this, CC-LR mice were sensitized to ovalbumin (OVA) and then challenged with an OVA aerosol weekly for 8 weeks. This resulted in eosinophilic lung inflammation associated with increased levels of T helper 2 cytokines and mucous metaplasia of airway epithelium, similar to what is seen in asthmatic patients. However, this type of inflammation did not result in a significant difference in lung surface tumor number (49 ± 9 in OVA vs. 52 ± 5 in control) in contrast to a 3.2-fold increase with COPD-like inflammation. Gene expression analysis of nontypeable Haemophilus influenzae (NTHi)-treated lungs showed upregulation of a different profile of inflammatory genes, including interleukin 6 (IL-6), compared with OVA-treated lungs. Therefore, to determine the causal role of cytokines that mediate COPD-like inflammation in lung carcinogenesis, we genetically ablated IL-6 in CC-LR mice. This not only inhibited intrinsic lung cancer development (1.7-fold) but also inhibited the promoting effect of extrinsic COPD-like airway inflammation (2.6-fold). We conclude that there is a clear specificity for the nature of inflammation in lung cancer promotion, and IL-6 has an essential role in lung cancer promotion. Cancer Prev Res; 4(1); 51–64. ©2010 AACR.

Promoting effect of neutrophils on lung tumorigenesis is mediated by CXCR2 and neutrophil elastase

BackgroundTumor cells produce various cytokines and chemokines that attract leukocytes. Leukocytes can amplify parenchymal innate immune responses, and have been shown to contribute to tumor promotion. Neutrophils are among the first cells to arrive at sites of inflammation, and the increased number of tumor-associated neutrophils is linked to poorer outcome in patients with lung cancer.ResultsWe have previously shown that COPD-like airway inflammation promotes lung cancer in a K-ras mutant mouse model of lung cancer (CC-LR). This was associated with severe lung neutrophilic influx due to the increased level of neutrophil chemoattractant, KC. To further study the role of neutrophils in lung tumorigenesis, we depleted neutrophils in CC-LR mice using an anti-neutrophil antibody. This resulted in a significant reduction in lung tumor number. We further selectively inhibited the main receptor for neutrophil chemo-attractant KC, CXCR2. Similarly, this resulted in suppression of neutrophil recruitment into the lung of CC-LR mice followed by significant tumor reduction. Neutrophil elastase (NE) is a potent elastolytic enzyme produced by neutrophils at the site of inflammation. We crossed the CC-LR mice with NE knock-out mice, and found that lack of NE significantly inhibits lung cancer development. These were associated with significant reduction in tumor cell proliferation and angiogenesis.ConclusionWe conclude that lung cancer promotion by inflammation is partly mediated by activation of the IL-8/CXCR2 pathway and subsequent recruitment of neutrophils and release of neutrophil elastase. This provides a baseline for future clinical trials using the IL-8/CXCR2 pathway or NE inhibitors in patients with lung cancer.

IL6 Blockade Reprograms the Lung Tumor Microenvironment to Limit the Development and Progression of K-ras–Mutant Lung Cancer

Activating mutations of K-ras are the most common oncogenic alterations found in lung cancer. Unfortunately, attempts to target K-ras-mutant lung tumors have thus far failed, clearly indicating the need for new approaches in patients with this molecular profile. We have previously shown NF-κB activation, release of IL6, and activation of its responsive transcription factor STAT3 in K-ras-mutant lung tumors, which was further amplified by the tumor-enhancing effect of chronic obstructive pulmonary disease (COPD)-type airway inflammation. These findings suggest an essential role for this inflammatory pathway in K-ras-mutant lung tumorigenesis and its enhancement by COPD. Therefore, here we blocked IL6 using a monoclonal anti-IL6 antibody in a K-ras-mutant mouse model of lung cancer in the absence or presence of COPD-type airway inflammation. IL6 blockade significantly inhibited lung cancer promotion, tumor cell-intrinsic STAT3 activation, tumor cell proliferation, and angiogenesis markers. Moreover, IL6 inhibition reduced expression of protumor type 2 molecules (arginase 1, Fizz 1, Mgl, and IDO), number of M2-type macrophages and granulocytic myeloid-derived suppressor cells, and protumor T-regulatory/Th17 cell responses. This was accompanied by increased expression of antitumor type 1 molecule (Nos2), and antitumor Th1/CD8 T-cell responses. Our study demonstrates that IL6 blockade not only has direct intrinsic inhibitory effect on tumor cells, but also reeducates the lung microenvironment toward an antitumor phenotype by altering the relative proportion between protumor and antitumor immune cells. This information introduces IL6 as a potential druggable target for prevention and treatment of K-ras-mutant lung tumors. Cancer Res; 76(11); 3189-99. ©2016 AACR.

Tumor necrosis factor links chronic obstructive pulmonary disease and K-ras mutant lung cancer through induction of an immunosuppressive pro-tumor microenvironment

ABSTRACT Tumor necrosis factor (TNF) is known as an important regulator of tumor microenvironment and inflammation. TNF levels are markedly elevated in the bronchoalveolar lavage fluid (BALF) of patients with chronic obstructive pulmonary disease (COPD), which is an independent risk factor for lung cancer. We have previously shown that COPD-like airway inflammation promotes lung cancer in a K-ras mutant mouse model (CC-LR mouse). This was associated with a significant increase of neutrophils in BALF, accompanied by a marked increase in TNF level, suggesting a link between COPD, TNF, and lung cancer promotion. Therefore, we first overexpressed TNF in the airway epithelium of CC-LR mice, which promoted lung cancer by ∼2-fold. This was associated with increased numbers of Ki67 and CD31 positive cells in lung tumors of CC-LR/TNF-Tg mice. We also found a robust increase in NF-κB activation, and numbers of neutrophils and myeloid-derived suppressor cells (MDSCs) in lung. Accordingly, we depleted MDSCs in CC-LR/TNF-Tg mice, which lead to significant tumor suppression emphasizing on the role of TNF-induced MDSCs in K-ras induced lung tumorigenesis. Finally, we targeted TNF expression by crossing CC-LR mice with TNF knock-out mice (CC-LR/TNF-KO), which resulted in a significant decrease in lung tumor burden in the absence or presence of COPD-like airway inflammation. Interestingly, there were less MDSCs and lower Ki67 and CD31 expression in the lung of the CC-LR/TNF-KO mice. We conclude that TNF links COPD to lung cancer promotion by induction of an immunosuppressive MDSC response, and subsequent amplification of proliferation and angiogenesis in tumors.

Abstract B43: Targeting tumor microenvironment for treatment of K-ras mutant lung cancer

Activating mutations of K-ras are one of the most common molecular alterations associated with lung cancer development. Several attempts to develop therapies directly targeting K-ras have been failed thus far, clearly state the need for new strategies to bring clinical benefits to patients displaying such a molecular profile. Using a conditional K-ras mutant lung cancer mouse model (CC-LR) we previously showed that K-ras mutated lung tumors have intrinsic inflammatory characteristics associated with NF-κB pathway activation. Therefore, CC-LR mice were crossed with IKK-β f/f mice to develop a K-ras mutant mouse with lack of NF-κB activity in airway epithelium. This changed the bronchoalveolar lavage fluid (BALF) cellular component of the CC-LR mice (mostly by reduction of macrophages), and resulted in a ∼70% (3.4-fold) reduction in lung surface tumor number. Lung of CC-LR mice also shows high protein level of IL-6 (downstream to NF-κB activation) and increased STAT3 gene expression (downstream signal to IL-6) plus infiltration of myeloid and Th17 cells. Accordingly, we genetically ablated IL-6 in the CC-LR mice. This significantly inhibited lung cancer development (1.7-fold, 41%) suggesting a role for IL-6 mediated signaling in tumor promotion probably through STAT3 pathway activation. IL-6 and STAT3 are required for differentiation of Th17 cells from naive T cells. Th17 cells mostly produce IL-17A that binds to the IL-17 receptor (IL-17R). IL-17R signaling is required for lung CXC chemokine expression and myeloid cell recruitment. Furthermore, IL-17A induces more production of IL-6 by epithelial cells. So, CC-LR mice were crossed with IL-17A KO mice. Lack of IL-17A in CC-LR mice resulted in a ∼70% (3.4-fold) tumor reduction. It also decreased the expression of pro-inflammatory mediators and reduced recruitment of myeloid cells. These reults suggest that K-ras initiated airway inflammation through NF-κB mediated activation of the IL-6/STAT3/Th17 signaling promotes lung tumorigenesis, and introduce IL-6 as a potential druggable target for lung cancer patients who harbor K-ras mutations. This prompted us to block IL-6 pathway using a monoclonal anti-IL-6 immunotherapy in our K-ras mutant model. Six week old CC-LR mice were injected intraperitoneally with 20 mg/kg dose of an anti-IL-6 monoclonal IgG1 antibody, twice a week, for a period of 8 weeks. Flowcytometry and qPCR analysis of total lung in non-treated CC-LR mice showed 2-fold increase in the population of tumor associated macrophage (TAM) and Arginase-1 mRNA expression (3 fold) during tumor progression from age 6 weeks to 14 weeks suggesting that epithelial signal initiated by K-ras mutation dictates an inflammatory type 2 pro-tumor fate for lung microenvironment. We further found that anti-IL-6 treatment suppressed tumor development by ∼78% (4.6-fold) in CC-LR mice with a significant reduction in the expression levels of Ki-67, VEGF, MMP9, CD31 and phospho-STAT3 in lung tissue. It also reduced TGFβ and KC protein levels in BALF with a significant decrease in Arginase1 mRNA expression (3-fold) and TAM population (5-fold) in total lung homogenate. We conclude that K-ras mutation drives an immunosuppressive pro-tumor response and blocking IL-6 shifts this to an anti-tumor lung microenvironment. Therefore we propose pharmacological targeting of IL-6 as a potential therapeutic strategy alone or in combination with conventional cytotoxic therapy for lung cancer patients with K-ras mutation. Funded by: American Cancer Society, RSG-11-115-01-CNE, and American Lung Association/LUNGevity Foundation, LCD-114696-N Citation Format: Mauricio da Silva Caetano, Seon Hee Chang, Amber M. Cumpian, Soudabeh Daliri, Maria Miguelina De La Garza, Cesar E. Ochoa, Chen Dong, Seyed Javad Moghaddam. Targeting tumor microenvironment for treatment of K-ras mutant lung cancer. [abstract]. In: Proceedings of the AACR Special Conference on RAS Oncogenes: From Biology to Therapy; Feb 24-27, 2014; Lake Buena Vista, FL. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(12 Suppl):Abstract nr B43. doi: 10.1158/1557-3125.RASONC14-B43

Abstract A13: Pharmacologic targeting of IL-6 suppresses tumor progression in a non-small cell lung cancer mouse model with K-ras mutation through re-educating the tumor microenvironment.

Activating mutations of K-ras are one of the most common molecular alterations associated with lung cancer development. Several attempts to develop therapies directly targeting K-ras have failed thus far, clearly state the need for new strategies to bring clinical benefits to patients displaying such molecular profile. Using a conditional K-ras mutated lung cancer mouse model (CC-LR) we previously showed that K-ras mutated lung tumors have intrinsic inflammatory characteristics and we also demonstrated that chronic obstructive pulmonary disease (COPD)-like airway inflammation, an independent risk factor for lung cancer, promotes lung tumor in this model. CC-LR mice shows high protein level of interleukin 6 (IL-6) and increased STAT3 (downstream signal to IL6) gene expression, and we have further shown that genetic ablation of IL-6 in CC-LR mice results in significant tumor reduction. High levels of IL-6 and up-regulation of STAT3 and its target genes have been observed in the lungs of smokers with COPD, and in 50% of human lung adenocarcinomas. These indicate an essential role for IL-6 in lung cancer promotion, and introduce IL-6 as a potential druggable target for lung cancer patients who harbor K-ras mutations. This prompted us to block IL-6 pathway using a monoclonal anti-IL-6 immunotherapy in our K-ras mutated lung cancer mouse model. Six week old CC-LR mice were injected intraperitoneally (I.P.) with 20 mg/kg dose of an anti-IL-6 monoclonal IgG1 antibody, twice a week, for a period of eight weeks. Flowcytometry analysis of total lung inflammatory cell population in non-treated CC-LR mice showed 2-fold increase in the population of tumor associated macrophage (TAM) (CD45+/CD11b+/GR1+/F4/80+/MCSFR+) during tumor progression from age 6 weeks to 14 weeks. qPCR analysis of total lung RNA from non-treated CC-LR mice showed that there is an increase in the level of Arginase-1 (3 fold) with no change in the level of inducible Nitric Oxide Synthetize (NOS2). This suggests that epithelial signal initiated by K-ras mutation may dictate the fate of lung microenvironment by creating an inflammatory pro-tumor type 2 response. Then we found that anti-IL-6 treatment suppresses tumor progression by ~78% (4.6-fold) in CC-LR mice which is associated with a significant reduction in the quantity of inflammatory cells in bronchoalveolar lavage fluid (BALF). It also decreased the expression of proliferation marker: Ki-67, and pro angiogenic factors: VEGF, MMP9 and CD31 and phospho-STAT3 in lung tissue. ELISA analysis of BALF from CC-LR mice also showed that anti-IL-6 treatment reduces TGFβ and KC protein levels with no change in level of IL-17. qPCR and flowcytometry analysis of total lung homogenate of CC-LR mice further showed that IL-6 blockade induces a significant decrease in Arginase1 expression (3-fold) and TAM population (5-fold). Taking together here we showed that K-ras mutated lung tumor drives an immunosuppressive pro-tumor microenvironment, with an M2 TAM polarization and blocking the suppressive actions of IL-6 shifts this to an anti-tumor lung microenvironment. Therefore we propose pharmacological targeting of IL-6 as a potential therapeutic strategy alone or in combination with conventional cytotoxic therapy for lung cancer patients with K-ras mutation. Funded by: American Cancer Society, RSG-11-115-01-CNE, and American Lung Association/LUNGevity Foundation, LCD-114696-N Citation Format: Mauricio S. Caetano, Amber M. Cumpian, Lei Gong, Cesar E. Ochoa, Seon H. Chang, Huiyuan Zhang, Stephanie Watowich, Cinthya Sternberg, Carlos G. Ferreira, Seyed J. Moghaddam. Pharmacologic targeting of IL-6 suppresses tumor progression in a non-small cell lung cancer mouse model with K-ras mutation through re-educating the tumor microenvironment. [abstract]. In: Proceedings of the AACR-IASLC Joint Conference on Molecular Origins of Lung Cancer; 2014 Jan 6-9; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2014;20(2Suppl):Abstract nr A13.

Abstract 4977: An essential role for neutrophils in lung cancer promotion .

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Lung cancer is the leading cause of cancer death worldwide, and cigarette smoking is the principal cause of it. Cigarette smoke-induced lung cancer is characterized by a deregulated inflammatory tumor microenvironment. Tumor cells produce various cytokines and chemokines that attract leukocytes. Leukocytes (innate and adaptive immune cells) can amplify parenchymal innate immune responses, and have been shown to contribute to tumor promotion. In addition, smokers with chronic obstructive pulmonary disease (COPD), an inflammatory disease of the lung, have an increased risk of lung cancer compared to smokers without COPD. These facts suggest a strong link between COPD-type inflammation and lung cancer promotion. In histopathologic specimens of lung and in bronchoalveolar lavage fluid (BALF) from COPD patients, neutrophils and macrophages are prominent. Neutrophils are among the first cells to arrive at sites of inflammation, and the increased number of tumor-associated neutrophils is linked to poorer outcome in patients with lung cancer. We have previously shown that COPD-like airway inflammation promotes lung cancer in a K-ras mutant mouse model of lung cancer (CC-LR). This was associated with severe neutrophilic influx due to increased level of neutrophil chemoattractant, KC, which was partially inhibited by using a natural non-specific anti-inflammatory agent, curcumin 1% in diet, and resulted in significant tumor suppression. To further study the role of neutrophil in lung tumorigenesis, we depleted neutrophils in CC-LR mice using an anti-neutrophil antibody, mLy6G, 5mg/kg twice a week by intraperitoneal injection. This resulted in complete lung neutrophil depletion and 68% (3.2-fold) reduction in lung surface tumor number. Neutrophil elastase (NE) is a potent elastolytic enzyme produced by neutrophils at the site of inflammation. It participates actively in COPD development and might contribute to tumor progression by activating proteolytic cascades. The concentration of NE in tumor extracts was also found to be linked to the invasiveness of lung cancer. Therefore, we crossed the CC-LR mice with NE knock out (KO) mice. We have found that lack of NE significantly inhibited lung cancer development by 43% (1.7-fold) without changing the BALF inflammatory cell component of the CC-LR mice. We further inhibited the main receptor for neutrophil chemo-attractant KC, CXCR2, using a selective inhibitor, SB332235Z, 50 mg/kg orally twice daily by gavage. Similarly, this also resulted in significant suppression of neutrophil recruitment into the lung of CC-LR mice followed by significant (∼64%, 2.8-fold) tumor reduction. We conclude that lung cancer promotion by inflammation partly mediated by activation of IL-8/CXCR2 pathway and subsequent recruitment of neutrophils and release of neutrophil elastase. This provides a baseline for future clinical trails using IL-8/CXCR2 pathway or NE inhibitors in patients with lung cancer. Citation Format: Lei Gong, Amber C. Cumpian, Cesar E. Ochoa, Daniel J. Lapid, Seyedeh Golsar Mirabolfathinejad, Maria Miguelina De la Garza, Seyed Javad Moghaddam. An essential role for neutrophils in lung cancer promotion . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4977. doi:10.1158/1538-7445.AM2013-4977

Abstract A32: Mechanistic Dissection of Lung Cancer Promotion by Airway Inflammation

Cigarette smoking is the principal cause of lung carcinogenesis, however, smokers with chronic obstructive pulmonary disease (COPD) have an increased risk of lung cancer (3 to 10 fold) compared to smokers with comparable cigarette exposure but without COPD. Histopathologic studies have clearly demonstrated lung inflammation in COPD, and it persists even after cessation of cigarette smoking. These facts suggest a strong link between COPD-related airway inflammation and lung cancer promotion independent of smoking but the precise mechanistic link is not known. We developed a COPD-like mouse model of airway inflammation through repeated aerosol challenge to a lysate of non-typeable Haemophilus influenzae (NTHi) which commonly colonizes the airways of COPD patients. Then, we showed that this type of airway inflammation, but not asthma-like airway inflammation, promotes lung cancer in a K-ras mutant mouse model of lung cancer (CC-LR). This was associated with NF-kB pathway activation, and up-regulation of its downstream target genes, including IL-6 and T helper 17 (Th17) response. Therefore, we studied the role of NF-kB in lung cancer promotion by targeting its expression in airway epithelium. CC-LR mice were crossed with IKK-βf/f mice to develop a mouse with lack of NF-kB activity in airway secretory cells (CC-LR-IKKβ mice). NF-kB deficiency in the airway epithelium changed the bronchoalveolar lavage fluid (BALF) cellular component (mostly reduction in macrophage number) of the CC-LR mice, and resulted in a ∼70% (3.4-fold) reduction in lung surface tumor number compared to age and sex matched control CC-LR mice. It also significantly reduced the number of visible tumors on the lung surface of the CC-LR mice by >60% (2.6-fold) after inducing COPD-like airway inflammation using weekly NTHi exposure for 8 weeks. We then genetically ablated IL-6 in the CC-LR mice. Lack of IL-6 did not change the BALF inflammatory cell component of the CC-LR mice. However, it not only inhibited intrinsic lung cancer development (1.7-fold, 41%), but also inhibited the promoting effect of extrinsic NTHi-induced COPD-like airway inflammation (2.6-fold, 62%) on lung carcinogenesis, suggesting a role for IL-6 mediated epithelial cell signaling in tumor promotion by COPDlike airway inflammation. This is under further investigation by our group. IL-6 is required for differentiation of Th17 cells from naive T cells. Th17 cells mostly produce IL-17A, and IL-17F. These both bind to the IL-17 receptor (IL-17R), and IL-17R signaling is required for lung CXC chemokine expression and neutrophil recruitment, however, we found that only the IL-17R KO and IL-17A KO but not IL-17F KO mice showed lower levels of neutrophilic influx into the BALF and less inflammatory cell infiltration in lung tissue in response to NTHi. Furthermore, IL-17A induces more production of IL-6 by epithelial cells. So, CC-LR mice were crossed with IL-17A KO mice. Lack of IL-17A resulted in a ∼70% (3.4-fold) reduction in lung surface tumor number compared to age and sex matched control CC-LR mice. It also significantly reduced the number of visible tumors on the lung surface of the CCLR mice by ∼54% (2.2-fold) after inducing COPD-like airway inflammation using weekly NTHi exposure for 4 weeks from the age of 10 weeks. We conclude that airway inflammation through NF-kB mediated activation of the IL-6/Th17 signaling pathway promotes lung carcinogenesis.