EURO-MUSCULUS/USPRM Basic Scanning Protocols for wrist and hand

In this protocol, the patient/probe positionings, anatomical drawings and ultrasound images of commonly scanned wrist/hand structures are described. This practical guide is prepared (with an international consensus of several expert physiatrists) to serve as a uniform/standard approach especially for beginner sonographers.

EURO-MUSCULUS/USPRM Basic Scanning Protocols for shoulder

In this protocol, the patient/probe positionings, anatomical drawings and ultrasound images of commonly scanned shoulder structures are described. This practical guide is prepared (with an international consensus of several expert physiatrists) to serve as a uniform/standard approach especially for beginner sonographers.

CYP2J2 and EETs Protect Against Lung Ischemia/Reperfusion Injury via Anti-Inflammatory Effects in Vivo and in Vitro

Background: Injurious inflammatory response is critical to the development of lung ischemia/reperfusion injury (LIRI). The cytochrome P450 epoxygenase 2J2 (CYP2J2) metabolizes arachidonic acid to epoxyeicosatrienoic acids (EETs), which exert an anti-inflammatory effect on the cardiovascular system. We therefore cytochrome hypothesized that CYP2J2 overexpression and pretreatment with exogenous EETs may have the potential to reduce LIRI. Methods: A rat model was used to mimic the condition of LIRI by clamping the left pulmonary hilum for 60 minutes, followed by reperfusion for 2 hours. Moreover, we developed a cell model using human pulmonary artery endothelial cells by anoxia for 8 hours, followed by reoxygenation for 16 hours to determine the anti-inflammatory effect and mechanism of CYP2J2 overexpression and exogenous 11,12-EET. Results: Lung ischemia/reperfusion increased lung wet/dry and lung weight/body weight ratios, protein concentration in bronchoalveolar lavage fluid and concentrations of pro-inflammatory, including mediators in serum IL-1ß, IL-8, TNF-a, sP- and sE-selectin, and decreased concentration of anti-inflammatory mediator IL-10. Ischemia/reperfusion also leaded to pulmonary edema and inflammation under light microscopy. Furthermore, activation of NF-γB p65 and degradation of IγBa were remarkably increased in ischemia/reperfusion lung tissues. While CYP2J2 overexpression significantly inhibited the above effects (p<0.05). In vitro data further confirmed the anti-inflammatory effect of CYP2J2 overexpression and 11,12-EET, an effect that may probably be mediated by PPARγ activation. Conclusion: CYP2J2 overexpression and administration of exogenous EETs can protect against LIRI via anti-inflammatory effects. This can be a novel potential strategy for prevention and treatment of LIRI.

Use of lung-preserving surgery in left inflammatory bronchial occlusion and distal atelectasis: preliminary results

OBJECTIVES

Lung-preserving surgery was proved to be effective and safe to treat patients with benign bronchial strictures. However, this surgical treatment has been rarely reported in patients with complete occlusion in the left main bronchus. The aim of this study was to assess the value of this procedure and report our experience in the treatment of these patients with left atelectasis caused by inflammatory bronchial occlusion.

METHODS

We reviewed and analysed the medical records of 8 patients who had undergone left main bronchus sleeve resection for symptomatic left atelectasis caused by inflammatory bronchial occlusion from May 2007 to April 2011.

RESULTS

Eight patients (3 men and 5 women) with a medical history of active pulmonary tuberculosis were involved in this study. The median age was 23 years. Parenchyma-sparing left main bronchus resection was performed in 4 patients, 1 of whom received partial wedge resection in the lingual lobe. Left main bronchus sleeve resection plus superior lobectomy was performed in 2 patients and left main bronchus sleeve resection plus left inferior lobectomy in 2 patients, 1 of whom received additional partial wedge resection of the lingual lobe. The procedure was completed successfully in all 8 patients without postoperative deaths. The mean follow-up time was 49.3 months, ranging from 23 to 69 months. No major complications, including stenosis and atelectasis, were observed during the follow-up period. The symptoms of pulmonary atelectasis disappeared and pulmonary ventilation function improved significantly.

CONCLUSIONS

In symptomatic patients with left atelectasis caused by inflammatory bronchial occlusion, lung-preserving surgery is an effective and safe surgical treatment.

Radiation doses of cerebral blood volume measurements using C-arm CT: A phantom study

BACKGROUND AND PURPOSE

Parenchymal blood volume measurement by C-arm CT facilitates in-room peritherapeutic perfusion evaluation. However, the radiation dose remains a major concern. This study aimed to compare the radiation dose of parenchymal blood volume measurement using C-arm CT with that of conventional CTP using multidetector CT.

MATERIALS AND METHODS

A biplane DSA equipped with C-arm CT and a Rando-Alderson phantom were used. Slab parenchymal blood volume (8-cm scanning range in a craniocaudal direction) and whole-brain parenchymal blood volume with identical scanning parameters, except for scanning ranges, were undertaken on DSA. Eighty thermoluminescent dosimeters were embedded into 22 organ sites of the phantom. We followed the guidelines of the International Commission on Radiation Protection number 103 to calculate the effective doses. For comparison, 8-cm CTP with the same phantom and thermoluminescent dosimeter distribution was performed on a multidetector CT. Two repeat dose experiments with the same scanning parameters and phantom and thermoluminescent dosimeter settings were conducted.

RESULTS

Brain-equivalent dose in slab parenchymal blood volume, whole-brain parenchymal blood volume, and CTP were 52.29 ± 35.31, 107.51 ± 31.20, and 163.55 ± 89.45 mSv, respectively. Variations in the measurement of an equivalent dose for the lens were highest in slab parenchymal blood volume (64.5%), followed by CTP (54.6%) and whole-brain parenchymal blood volume (29.0%). The effective doses of slab parenchymal blood volume, whole-brain parenchymal blood volume, and CTP were 0.87 ± 0.55, 3.91 ± 0.78, and 2.77 ± 1.59 mSv, respectively.

CONCLUSIONS

The dose measurement conducted in the current study was reliable and reproducible. The effective dose of slab parenchymal blood volume is about one-third that of CTP. With the advantages of on-site and immediate imaging availability and saving procedural time and patient transportation, slab parenchymal blood volume measurement using C-arm CT can be recommended for clinical application.

CYP2J2 and EETs Protect against Oxidative Stress and Apoptosis in Vivo and in Vitro Following Lung Ischemia/Reperfusion

BACKGROUND

Cytochrome P450 epoxygenase 2J2 (CYP2J2) metabolizes arachidonic acids to epoxyeicosatrienoic acids (EETs). EETs exert various biological effects, including anti-inflammatory, anti-apoptotic, pro-proliferation, pro-angiogenesis, anti-oxidation, and anti-fibrosis effects. However, little is known about the role of CYP2J2 and EETs in lung ischemia/reperfusion injury. In this study, we examined the effects of exogenous EETs or CYP2J2 overexpression on lung ischemia/reperfusion injury in vivo and in vitro.

METHODS AND RESULTS

CYP2J2 gene was stably transfected into rat lungs via pcDNA3.1-CYP2J2 plasmid delivery, resulting in increased EETs levels in the serum and lung. A rat model of lung ischemia/reperfusion injury was developed by clamping the left lung hilum for 1 hour, followed by reperfusion for 2 hours. We found that CYP2J2 overexpression markedly decreased the levels of oxidative stress and cell apoptosis in lung tissues induced by ischemia/reperfusion. Moreover, we observed that exogenous EETs, or CYP2J2 overexpression, enhanced cell viability, decreased intracellular reactive oxygen species (ROS) generation, inhibited mitochondrial dysfunction, and attenuated several apoptotic signaling events in a human pulmonary artery endothelial cells (HPAECs)-based anoxia/reoxygenation model. These apoptotic events included activation of NADPH oxidase, collapse of mitochondrial transmembrane potential, and activation of pro-apoptotic proteins and caspase-3. These effects were mediated, at least partially, by the PI3K/Akt signaling pathway.

CONCLUSION

These results reveal that CYP2J2 overexpression and exogenous EETs can protect against oxidative stress and apoptosis following lung ischemia/reperfusion in vivo and in vitro, suggesting that increasing the level of EETs may be a novel promising strategy to prevent and treat lung ischemia/reperfusion injury.

Physician Scientist Training in the United States: A Survey of the Current Literature

The declining number of physician scientists is an alarming issue. A systematic review of all existing programs described in the literature was performed, so as to highlight which programs may serve as the best models for the training of successful physician scientists. Multiple databases were searched, and 1,294 articles related to physician scientist training were identified. Preference was given to studies that looked at number of confirmed publications and/or research grants as primary outcomes. Thirteen programs were identified in nine studies. Eighty-three percent of Medical Scientist Training Program (MSTP) graduates, 77% of Clinician Investigator Training Program (CI) graduates, and only 16% of Medical Fellows Program graduates entered a career in academics. Seventy-eight percent of MSTP graduates succeeded in obtaining National Institute of Health (NIH) grants, while only 15% of Mayo Clinic National Research Service Award-T32 graduates obtained NIH grants. MSTP physician scientists who graduated in 1990 had 13.5 ± 12.5 publications, while MSTP physician scientists who graduated in 1975 had 51.2 ± 38.3 publications. Additionally, graduates from the Mayo Clinic's MD-PhD Program, the CI Program, and the NSRA Program had 18.2 ± 20.1, 26.5 ± 24.5, and 17.9 ± 26.3 publications, respectively. MSTP is a successful model for the training of physician scientists in the United States, but training at the postgraduate level also shows promising outcomes. An increase in the number of positions available for training at the postgraduate level should be considered.

Receptor-interacting protein 1 increases chemoresistance by maintaining inhibitor of apoptosis protein levels and reducing reactive oxygen species through a microRNA-146a-mediated catalase pathway

Although receptor-interacting protein 1 (RIP1) is well known as a key mediator in cell survival and death signaling, whether RIP1 directly contributes to chemotherapy response in cancer has not been determined. In this report, we found that, in human lung cancer cells, knockdown of RIP1 substantially increased cytotoxicity induced by the frontline anticancer therapeutic drug cisplatin, which has been associated with robust cellular reactive oxygen species (ROS) accumulation and enhanced apoptosis. Scavenging ROS dramatically protected RIP1 knockdown cells against cisplatin-induced cytotoxicity. Furthermore, we found that, in RIP1 knockdown cells, the expression of the hydrogen peroxide-reducing enzyme catalase was dramatically reduced, which was associated with increased miR-146a expression. Inhibition of microRNA-146a restored catalase expression, suppressed ROS induction, and protected against cytotoxicity in cisplatin-treated RIP1 knockdown cells, suggesting that RIP1 maintains catalase expression to restrain ROS levels in therapy response in cancer cells. Additionally, cisplatin significantly triggered the proteasomal degradation of cellular inhibitor of apoptosis protein 1 and 2 (c-IAP1 and c-IAP2), and X-linked inhibitor of apoptosis (XIAP) in a ROS-dependent manner, and in RIP1 knockdown cells, ectopic expression of c-IAP2 attenuated cisplatin-induced cytotoxicity. Thus, our results establish a chemoresistant role for RIP1 that maintains inhibitor of apoptosis protein (IAP) expression by release of microRNA-146a-mediated catalase suppression, where intervention within this pathway may be exploited for chemosensitization.

Novel diagnosis and treatment of esophageal granular cell tumor: report of 14 cases and review of the literature

BACKGROUND

Granular cell tumors (GCT), especially in the esophagus, are rare neoplasms originating from the nervous system. There is still some controversy regarding the diagnosis and treatment of esophageal GCT.

METHODS

We report 14 cases of esophageal GCT diagnosed and treated from January 2004 to March 2013. Their clinical manifestations, endoscopic image, endoscopic ultrasonography (EUS) appearance, pathology, immunohistochemistry, treatment, and prognosis were reviewed.

RESULTS

The typical images of EUS were hypoechoic, homogenous, and smooth-edged tumors restricted to deep mucosal and submucosal layers. However, there were 2 cases with tumors invading muscular layer. Endoscopic ultrasonography was valuable to assess the tumor size, location, depth of invasion, and nature. According to EUS manifestation, 11 cases with lesions 3 cm or less in diameter without muscular layer invasion underwent endoscopic resection without complication and the other 3 cases underwent surgical resection. A new technique of submucosal tunnel endoscopic resection was performed in 3 submucosal cases with lesions ranging from 2 cm to 3 cm in diameter. All of these cases were benign and histology was necessary for differential diagnosis.

CONCLUSIONS

Endoscopic ultrasonography plays an important guiding role in the diagnosis and treatment of esophageal GCT. Submucosal tunnel endoscopic resection is safe and effective. Further study is needed to determine whether this technique can be expanded into other applications.

RIP1 potentiates BPDE-induced transformation in human bronchial epithelial cells through catalase-mediated suppression of excessive reactive oxygen species

Cell survival signaling is important for the malignant phenotypes of cancer cells. Although the role of receptor-interacting protein 1 (RIP1) in cell survival signaling is well documented, whether RIP1 is directly involved in cancer development has never been studied. In this report, we found that RIP1 expression is substantially increased in human non-small cell lung cancer and mouse lung tumor tissues. RIP1 expression was remarkably increased in cigarette smoke-exposed mouse lung. In human bronchial epithelial cells (HBECs), RIP1 was significantly induced by cigarette smoke extract or benzo[a]pyrene diol epoxide (BPDE), the active form of the tobacco-specific carcinogen benzo(a)pyrene. In RIP1 knockdown HBECs, BPDE-induced cytotoxicity was significantly increased, which was associated with induction of cellular reactive oxygen species (ROS) and activation of mitogen-activated protein kinases (MAPKs), including c-jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and p38. Scavenging ROS suppressed BPDE-induced MAPK activation and inhibiting ROS or MAPKs substantially blocked BPDE-induced cytotoxicity, suggesting ROS-mediated MAPK activation is involved in BPDE-induced cell death. The ROS-reducing enzyme catalase is destabilized in an ERK- and JNK-dependent manner in RIP1 knockdown HBECs and application of catalase effectively blocked BPDE-induced ROS accumulation and cytotoxicity. Importantly, BPDE-induced transformation of HBECs was significantly reduced when RIP1 expression was suppressed. Altogether, these results strongly suggest an oncogenic role for RIP1, which promotes malignant transformation through protecting DNA-damaged cells against carcinogen-induced cytotoxicity associated with excessive ROS production.

Abstract 2910: Suppressing excessive reactive oxygen species accumulation by RIP1 potentiates BPDE-induced transformation of human bronchial epithelial cells

Cell survival signaling is important for the malignant phenotypes of cancer cells. Although the role of receptor-interacting protein 1 (RIP1) in cell survival signaling is well documented, whether RIP1 is directly involved in cancer development has never been studied. In this report, we found that RIP1 expression is substantially increased in human non-small cell lung cancer (NSCLC) tissues and cell lines. RIP1 expression in human bronchial epithelial cells (HBECs) was significantly induced by cigarette smoke extract (CSE) or benzo[a]pyrene diol epoxide (BPDE), the active form of the tobacco-specific carcinogen benzo (a) pyrene (BaP). In RIP1 knockdown HBECs, BPDE-induced cytotoxicity was significantly increased, which was associated with induction of cellular reactive oxygen species (ROS), mainly hydrogen peroxide (H2O2), and activation of mitogen-activated protein kinases (MAPKs) including JNK, ERK and p38. Scavenging ROS suppressed BPDE-induced MAPK activation and inhibiting ROS or MAPKs substantially blocked BPDE-induced cytotoxicity, suggesting ROS-mediated MAPK activation is involved in BPDE-induced cell death. The H2O2-reducing enzyme catalase is destabilized in an ERK- and JNK-dependent manner in RIP1 knockdown HBECs and application of catalase effectively blocked BPDE-induced H2O2 accumulation and cytotoxicity. Importantly, BPDE-induced transformation of HBECs was significantly reduced when RIP1 expression was suppressed. Altogether, these results strongly suggest an oncogenic role for RIP1, which promotes malignant transformation through protecting DNA-damaged cells against carcinogen-induced cytotoxicity associated with excessive ROS production.

Citation Format: Qiong Wang, Wenshu Chen, Xiuling Xu, Bilan Li, Weiyang He, Mabel T. Padilla. Suppressing excessive reactive oxygen species accumulation by RIP1 potentiates BPDE-induced transformation of human bronchial epithelial cells. [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 2910. doi:10.1158/1538-7445.AM2013-2910

Low-dose gamma-irradiation inhibits IL-6 secretion from human lung fibroblasts that promotes bronchial epithelial cell transformation by cigarette-smoke carcinogen

Despite decades of research in defining the health effects of low-dose (<100 mGy) ionizing photon radiation (LDR), the relationship between LDR and human cancer risk remains elusive. Because chemical carcinogens modify the tumor microenvironment, which is critical for cancer development, we investigated the role and mechanism of LDR in modulating the response of stromal cells to chemical carcinogen-induced lung cancer development. Secretion of proinflammatory cytokines such as interleukin-6 (IL-6), CXCL1 and CXCL5 from human lung fibroblasts was induced by cigarette-smoke carcinogen benzo[a]pyrene diol epoxide (BPDE), which was inhibited by a single dose of LDR. The activation of NF-κB, which is important for BPDE-induced IL-6 secretion, was also effectively suppressed by LDR. In addition, conditioned media from BPDE-treated fibroblasts activated STAT3 in the immortalized normal human bronchial epithelial cell line Beas-2B, which was blocked with an IL-6 neutralizing antibody. Conditioned medium from LDR-primed and BPDE-treated fibroblast showed diminished capacity in activating STAT3. Furthermore, IL-6 enhanced BPDE-induced Beas-2B cell transformation in vitro. These results suggest that LDR inhibits cigarette smoke-induced lung carcinogenesis by suppressing secretion of cytokines such as IL-6 from fibroblasts in lung tumor-prone microenvironment.

Protein-losing enteropathy and premature ovarian failure in a young woman with systemic lupus erythematosus

Protein-losing enteropathy (PLE) and autoimmune oophoritis are unusual manifestations of systemic lupus erythematosus (SLE). Autoimmune oophoritis may result in menstrual disturbance and spontaneous premature ovarian failure. However, there is no validated examination to confirm the diagnosis and it is easily neglected in patients with ovarian insufficiency. A 31-year-old woman with SLE presented with PLE and autoimmune oophoritis during the long course of flares and remissions in her lupus activity. The synchronism implied the association between the two. Moreover, both conditions simultaneously had a good response to cyclosporine A (CsA) therapy.

Abstract 393: Low-dose gamma-irradiation inhibits IL-6 secretion from human lung fibroblasts to suppress bronchial epithelial cell transformation by cigarette smoke carcinogen

The relationship between low-dose (&lt;100 mSv) ionizing radiation (LDR) and human cancer risk is controversial. While microenvironment consisting of stromal cells, cytokines and growth factors is modulated by carcinogens to favor carcinogenesis, how LDR impacts this oncogenic process is not well understood. In this study, we investigated the role and mechanism of low-dose ionizing radiation in modulating the response of human lung fibroblasts to carcinogen stimulation and the impacts of which on bronchial epithelial cell transformation. Using a human cytokine antibody array, we found that secretion of proinflammatory cytokines IL-6, CXCL1 and CXCL5 from human lung fibroblasts was induced by cigarette smoke carcinogen benzo[a]pyrene diol epoxide (BPDE), which was inhibited by a low dose of γ-ray irradiation. BPDE induced IL-6 secretion from lung fibroblasts in a dose-dependent manner, which was suppressed when the NF-κB and ERK pathways were blocked. LDR effectively inhibited NF-κB but not ERK activated by BPDE, suggesting that NF-κB is the target for LDR in fibroblasts. In addition, conditioned media from BPDE-treated fibroblasts activated STAT3 in the immortalized human bronchial epithelial cell line Beas-2B, which was blocked with an IL-6 neutralizing antibody as well as by pretreating fibroblasts with LDR. Furthermore, IL-6 significantly enhanced BPDE-induced Beas-2B cell transformation in vitro. These results suggest that LDR inhibits cigarette smoke carcinogen-induced lung carcinogenesis through suppressing secretion of protumorigenic cytokines such as IL-6 from fibroblasts in the tumor-prone microenvironment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 393. doi:1538-7445.AM2012-393

Abstract 2277: Autophagy-associated necroptosis contributes to cancer cell cytotoxicity induced by the chalcone compound SBC2

Chalcone-based compounds are potential agents for cancer chemoprevention and chemotherapy. The recently developed chalcone-based compound SBC2 suppresses xenograft tumor growth in nude mice, however, the mechanisms by which SBC2 kills cancer cells are elusive. In this study, we have investigated the cellular signaling pathways involved in SBC2's cytotoxicity in cancer cells derived from lung and bladder tumors. SBC2 potently killed different cancer cells, which was effectively blocked by the necroptosis inhibitor Necrostatin-1 and knockdown of the necroptosis pathway components RIP1 and RIP3, suggesting that SBC2-induced cytotoxicity is associated with necroptosis. SBC2 robustly activated JNK and ERK through activation of their upstream activating kinases MEKK1 and MKK7. Blocking JNK and ERK effectively blocked SBC2-induced cytotoxicity, implying an important role of these MAPKs in SBC2-induced cancer cell death. In addition, SBC2 strongly induced autophagy, which was suppressed when JNK was blocked. Furthermore, SBC2 triggered BCL-XL phosphorylation that was dependent on JNK. Importantly, suppression of autophagy with either pharmacological inhibitors or a siRNA targeting the essential autophagy component ATG7 effectively attenuated SBC2-induced cell death. These results suggest that SBC2 kills cancer cells through activating JNK-mediated and autophagy-associated necroptosis. Taken together, our observations substantiate SBC2 as a potential anticancer therapeutic and identify a novel pathway for cancer cell killing by SBC2 that involves autophagy and necroptosis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2277. doi:1538-7445.AM2012-2277

Abstract 385: Potentiating MUC1 expression in human bronchial epithelial cells by cigarette smoke carcinogens through induction of TNF-α secretion from macrophages

Although an important role of inflammation in the development of lung cancer has been recognized, how inflammation promotes lung epithelial cell transformation and lung cancer development has not been well elucidated. Cigarette smoke (CS), the major cause of lung cancers, potently elicits chronic pulmonary inflammation. Our recent studies have found that CS significantly induces Muc1 (MUC1 for human and Muc1 for nonhuman species) expression in mouse bronchial epithelial cells and macrophages, and MUC1 facilitates Benzo(a)pyrene diolepoxide (BPDE)-induced human lung epithelial cell transformation. In this study, we investigated the role of inflammatory cells in regulating CS carcinogen-induced MUC1 expression in bronchial epithelial cells. BPDE and N-Nitroso-N-methylurea (MNU), an active CS carcinogen and a mimic, strongly induced tumor necrosis factor-alpha (TNF-α) secretion from human macrophages. The TNF-α induction was effectively blocked when ERK, JNK, and NF-κB were blocked, suggesting these pathways are involved in the induction of TNF-α from macrophages by BPDE and MNU. Interestingly, knockdown of MUC1 in macrophages suppressed BPDE- or MNU-induced TNF-α secretion, suggesting MUC1 plays a role in modulating carcinogen-induced and macrophage-mediated inflammatory responses. Conditioned media from BPDE- or MNU-treated macrophages potently induced MUC1 expression in human bronchial epithelial cells (HBECs), which was inhibited by a TNF-α neutralizing antibody, suggesting that TNF-α derived from macrophages contributes to CS carcinogen-induced MUC1 expression in HBECs. Thus, our results establish a dual role of MUC1 in CS-induced and inflammation-associated lung cancer development: to facilitate TNF-α secretion from macrophages and to potentiate transformation of HBECs. Note: This work is supported by NIH/NIEHS grant 1R01ES017328.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 385. doi:1538-7445.AM2012-385

MUC1 contributes to BPDE-induced human bronchial epithelial cell transformation through facilitating EGFR activation

Although it is well known that epidermal growth factor receptor (EGFR) is involved in lung cancer progression, whether EGFR contributes to lung epithelial cell transformation is less clear. Mucin 1 (MUC1 in human and Muc1 in animals), a glycoprotein component of airway mucus, is overexpressed in lung tumors; however, its role and underlying mechanisms in early stage lung carcinogenesis is still elusive. This study provides strong evidence demonstrating that EGFR and MUC1 are involved in bronchial epithelial cell transformation. Knockdown of MUC1 expression significantly reduced transformation of immortalized human bronchial epithelial cells induced by benzo[a]pyrene diol epoxide (BPDE), the active form of the cigarette smoke (CS) carcinogen benzo(a)pyrene (BaP)s. BPDE exposure robustly activated a pathway consisting of EGFR, Akt and ERK, and blocking this pathway significantly increased BPDE-induced cell death and inhibited cell transformation. Suppression of MUC1 expression resulted in EGFR destabilization and inhibition of the BPDE-induced activation of Akt and ERK and increase of cytotoxicity. These results strongly suggest an important role for EGFR in BPDE-induced transformation, and substantiate that MUC1 is involved in lung cancer development, at least partly through mediating carcinogen-induced activation of the EGFR-mediated cell survival pathway that facilitates cell transformation.

A superoxide-mediated mitogen-activated protein kinase phosphatase-1 degradation and c-Jun NH(2)-terminal kinase activation pathway for luteolin-induced lung cancer cytotoxicity

Although luteolin is identified as a potential cancer therapeutic and preventive agent because of its potent cancer cell-killing activity, the molecular mechanisms by which its cancer cell cytotoxicity is achieved have not been well elucidated. In this report, luteolin-induced cellular signaling was systematically investigated, and a novel pathway for luteolin's lung cancer killing was identified. The results show that induction of superoxide is an early and crucial step for luteolin-induced apoptotic and nonapoptotic death in lung cancer cells. The c-Jun N-terminal kinase (JNK) was potently activated after superoxide accumulation. Suppression of superoxide completely blocked luteolin-induced JNK activation, which was well correlated to alleviation of luteolin's cytotoxicity. Although luteolin slightly stimulated the JNK-activating kinase mitogen-activated protein kinase kinase 7, the latter was not dependent on superoxide. We further found that luteolin triggers a superoxide-dependent rapid degradation of the JNK-inactivating phosphatase mitogen-activated protein kinase phosphatase-1 (MKP-1). Introduction of a degradation-resistant MKP-1 mutant effectively attenuated luteolin-induced JNK activation and cytotoxicity, suggesting that inhibition of the JNK suppressor MKP-1 plays a major role in luteolin-induced lung cancer cell death. Taken together, our results unveil a novel pathway consisting of superoxide, MKP-1, and JNK for luteolin's cytotoxicity in lung cancer cells, and manipulation of this pathway could be a useful approach for applying luteolin for lung cancer prevention and therapy.

Oxidized phospholipid-induced inflammation is mediated by Toll-like receptor 2

Oxidative tissue damage is a hallmark of many chronic inflammatory diseases. However, the precise mechanisms linking oxidative changes to inflammatory reactions remain unclear. Herein we show that Toll-like receptor 2 (TLR2) translates oxidative tissue damage into inflammatory responses by mediating the effects of oxidized phospholipids. Intraperitoneal injection of oxidized 1-palmitoyl-2-arachidonyl-sn-3-glycerophosphorylcholine (OxPAPC) resulted in upregulation of inflammatory genes in wild-type, but not in TLR2(-/-) mice. In vitro, OxPAPC induced TLR2 (but not TLR4)-dependent inflammatory gene expression and JNK and p38 signaling in macrophages. Induction of TLR2-dependent gene expression required reducible functional groups on sn-2 acyl chains of oxidized phospholipids, as well as serum cofactors. Finally, TLR2(-/-) mice were protected against carbon tetrachloride-induced oxidative tissue damage and inflammation, which was accompanied by accumulation of oxidized phospholipids in livers. Together, our findings demonstrate that TLR2 mediates cellular responses to oxidative tissue damage and they provide new insights into how oxidative stress is linked to acute and chronic inflammation.

Small interference RNA targeting tissue factor inhibits human lung adenocarcinoma growth in vitro and in vivo

Background

The human coagulation trigger tissue factor (TF) is overexpressed in several types of cancer and involved in tumor growth, vascularization, and metastasis. To explore the role of TF in biological processes of lung adenocarcinoma, we used RNA interference (RNAi) technology to silence TF in a lung adenocarcinoma cell line A549 with high-level expression of TF and evaluate its antitumor effects in vitro and in vivo.

Methods

The specific small interfering RNA (siRNA) designed for targeting human TF was transfected into A549 cells. The expression of TF was detected by reverse transcription-PCR and Western blot. Cell proliferation was measured by MTT and clonogenic assays. Cell apoptosis was assessed by flow cytometry. The metastatic potential of A549 cells was determined by wound healing, the mobility and Matrigel invasion assays. Expressions of PI3K/Akt, Erk1/2, VEGF and MMP-2/-9 in transfected cells were detected by Western blot. In vivo, the effect of TF-siRNA on the growth of A549 lung adenocarcinoma xenografts in nude mice was investigated.

Results

TF -siRNA significantly reduced the expression of TF in the mRNA and protein levels. The down-regulation of TF in A549 cells resulted in the suppression of cell proliferation, invasion and metastasis and induced cell apoptosis in dose-dependent manner. Erk MAPK, PI3K/Akt pathways as well as VEGF and MMP-2/-9 expressions were inhibited in TF-siRNA transfected cells. Moreover, intratumoral injection of siRNA targeting TF suppressed the tumor growth of A549 cells in vivo model of lung adenocarcinoma.

Conclusions

Down-regulation of TF using siRNA could provide a potential approach for gene therapy against lung adenocarcinoma, and the antitumor effects may be associated with inhibition of Erk MAPK, PI3K/Akt pathways.

Epidermal growth factor receptor-mediated tissue transglutaminase overexpression couples acquired tumor necrosis factor-related apoptosis-inducing ligand resistance and migration through c-FLIP and MMP-9 proteins in lung cancer cells

Acquired chemoresistance not only blunts anticancer therapy but may also promote cancer cell migration and metastasis. Our previous studies have revealed that acquired tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance in lung cancer cells is associated with Akt-mediated stabilization of cellular caspase 8 and Fas-associated death domain (FADD)-like apoptosis regulator-like inhibitory protein (c-FLIP) and myeloid cell leukemia 1 (Mcl-1). In this report, we show that cells with acquired TRAIL resistance have significantly increased capacities in migration and invasion. By gene expression screening, tissue transglutaminase (TGM2) was identified as one of the genes with the highest expression increase in TRAIL-resistant cells. Suppressing TGM2 dramatically alleviated TRAIL resistance and cell migration, suggesting that TGM2 contributes to these two phenotypes in TRAIL-resistant cells. TGM2-mediated TRAIL resistance is likely through c-FLIP because TGM2 suppression significantly reduced c-FLIP but not Mcl-1 expression. The expression of matrix metalloproteinase 9 (MMP-9) was suppressed when TGM2 was inhibited, suggesting that TGM2 potentiates cell migration through up-regulating MMP-9 expression. We found that EGF receptor (EGFR) was highly active in the TRAIL-resistant cells, and suppression of EGFR dramatically reduced TGM2 expression. We further determined JNK and ERK, but not Akt and NF-κB, are responsible for EGFR-mediated TGM2 expression. These results identify a novel pathway that involves EGFR, MAPK (JNK and ERK), and TGM2 for acquired TRAIL resistance and cell migration in lung cancer cells. Because TGM2 couples TRAIL resistance and cell migration, it could be a molecular target for circumventing acquired chemoresistance and metastasis in lung cancer.

Abstract 2338: EGFR-mediated TGM2 overexpression couples acquired TRAIL-resistance and migration involving c-FLIP and MMP9 in NSCLC cells

Acquired chemoresistance not only blunts cancer chemotherapy, but may also promote cancer cell migration and metastasis. Our previous studies have revealed that acquired tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) resistance in non-small cell lung cancer (NSCLC) cells was associated with Akt-mediated stabilization of cellular FLICE-like inhibitory protein (c-FLIP) and myeloid cell leukemia 1 (Mcl-1). The cells with acquired TRAIL-resistance have significantly increased migration and invasion potential. Gene expression array assay was used to explore the mechanism underlying TRAIL-resistance associated migration, and tissue transglutaminase 2 (TGM2) was identified as one of the genes with the highest expressing increase in TRAIL-resistant cells. Suppressing TGM2 activity or expression dramatically alleviated TRAIL-resistance and cell migration, suggesting TGM2 contributes to the both phenotypes in the TRAIL-resistant cells. TGM2 suppression significantly reduced c-FLIPL but not Mcl-1L expression, suggesting that TGM2 mediates TRAIL-resistance through c-FLIP. The expression of MMP9, a matrix metalloproteinase involved in cancer cell migration, was suppressed when TGM2 was inhibited, suggesting that TGM2 potentiates cell migration through upregulating MMP-9 expression. Furthermore, we found that EGFR was highly upregulated and activated and suppression of which dramatically reduced the expression level of TGM2 in the TRAIL-resistant cells. With chemical inhibitors, we further determined MAPKs (JNK and ERK), but not Akt and NF-κB, are responsible for EGFR-mediated TGM2 expression. Conversely, suppression of TGM2 had no effect on ERK, JNK and Akt activity. These results identify a novel pathway that involves EGFR, MAPK and TGM2 for acquired TRAIL-resistance and cell migration in NSCLC cells. Because TGM2 converges acquired TRAIL-resistance and cell migration, it could be a molecular target for circumventing acquired chemoresistance and metastasis in lung cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2338. doi:10.1158/1538-7445.AM2011-2338

Abstract 1337: MUC1 facilitates BPDE-induced EGFR activation and malignant transformation in human bronchial epithelial cells

Inflammation has emerged as an important factor for the development of lung cancer. However, the gene targets and pathways that are involved in inflammation-associated lung cancer development have not been clearly elucidated. Cigarette smoke (CS), which causes chronic pulmonary inflammation, is an established risk factor for lung cancer. MUC1 (MUC in human and Muc in animals), a mucin-like glycoprotein expressed on the surface of airway epithelial cells, is inducible during lung inflammation. MUC1 is also overexpressed as a tumor antigen in lung tumors. We found that chronic CS exposure significantly increased Muc1 expression in mouse airway epithelial cells associated with infiltration of inflammatory cells to the lung. The role of MUC1 in lung epithelial cell transformation induced by benzo[a]pyrene diol epoxide (BPDE), the active form of the CS carcinogen benzo(a)pyrene (BaP), was examined in an in vitro cell transformation assay. Knockdown of MUC1 by shRNA significantly reduced the efficacy of BPDE-induced transformation of BEAS-2B, an SV40 large T antigen immortalized human bronchial epithelial cell line. BPDE strongly activated EGFR and Akt in BEAS-2B cells. Akt activation was blocked with an EGFR inhibitor, suggesting that BPDE activates the EGFR/Akt cascade. Blocking this cascade with inhibitors for either EGFR or Akt significantly inhibited BPDE-induced cell transformation, supporting a critical role for EGFR and Akt activation in BPDE-induced cell transformation. Interestingly, the BPDE-induced activation of EGFR and Akt was attenuated when MUC1 expression was knocked down. Suppression of EGFR or Akt significantly increased BPDE's cytotoxicity. Consistently, the MUC1-suppressed BEAS-2B cells were more sensitive to BPDE-induced death. Taken together, these results suggest that MUC1 plays an oncogenic role in the early stages of inflammation-associated lung cancer development, at least partly through mediating carcinogen-induced activation of the EGFR/Akt pathway that potentiates survival in immortalized bronchial epithelial cells.

This work is supported by 1R01ES017328.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1337. doi:10.1158/1538-7445.AM2011-1337

NF-kappaB in lung cancer, a carcinogenesis mediator and a prevention and therapy target

Lung cancer ranks as the first malignant tumor killer worldwide. Despite the knowledge that carcinogens from tobacco smoke and the environment constitute the main causes of lung cancer, the mechanisms for lung carcinogenesis are still elusive. Cancer development and progression depend on the balance between cell survival and death signals. Common cell survival signaling pathways are activated by carcinogens as well as by inflammatory cytokines, which contribute substantially to cancer development. As a major cell survival signal, nuclear factor-kappaB (NF-kappaB) is involved in multiple steps in carcinogenesis and in cancer cell's resistance to chemo- and radio-therapy. Recent studies with animal models and cell culture systems have established the links between NF-kappaB and lung carcinogenesis, highlighting the significance of targeting NF-kappa signaling pathway for lung cancer treatment and chemoprevention. In this review, we summarize progresses in understanding the NF-kappaB pathway in lung cancer development as well as in modulating NF-kappaB for lung cancer prevention and therapy.