Ni Zhang

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.

Thoracoscopic Lobectomy versus Open Lobectomy in Stage I Non-Small Cell Lung Cancer: A Meta-Analysis

The objective of the present meta-analysis was to evaluate the survival, recurrence rate, and complications in patients with stage I non-small cell lung cancer (NSCLC) who received video-assisted thoracoscopic surgery (VATS) or open lobectomy. A literature search was conducted on June 31, 2012 using combinations of the search terms video-assisted thoracic surgery, open thoracotomy, lobectomy, and non-small-cell lung cancer (NSCLC). Inclusion criteria were: 1) Compared video-assisted thoracic surgery (VATS) lobectomy with open lobectomy. 2) Stage I NSCLC. 2) No previous treatment for lung cancer. 4) Outcome data included 5-year survival rate, complication, and recurrence rate. Tests of heterogeneity, sensitivity, and publication bias were performed. A total of 23 studies (21 retrospective and 2 prospective) met the inclusion criteria. VATS was associated with a longer 5-year survival (odds ratio [OR] = 1.622, 95% confidence interval [CI] 1.272 to 2.069; P<0.001), higher local recurrence rate (OR = 2.152, 95% CI 1.349 to 3.434; P = 0.001), similar distant recurrence rate (OR = 0.91, 95% CI 0.33 to 2.48; P = 0.8560), and lower total complication rate (OR = 0.45, 95% CI 0.24 to 0.84; P = 0.013) compared to open lobectomy. VATS was also associated with lower rates arrhythmias, prolonged air leakage, and pneumonia but it did not show any statistical significance. Patients with stage I NSCLC undergoing VATS lobectomy had longer survival and fewer complications than those who received open lobectomy.

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

BackgroundThe 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.MethodsThe 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.ResultsTF -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.ConclusionsDown-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.

Effects of TGF-β signaling blockade on human A549 lung adenocarcinoma cell lines.

Transforming growth factor β (TGF-β) is overexpressed in a wide variety of cancer types including lung adenocarcinoma (LAC), and the TGF-β signaling pathway plays an important role in tumor development. To determine whether blockade of the TGF-β signaling pathway can inhibit the malignant biological behavior of LAC, RNA interference (RNAi) technology was used to silence the expression of TGF-β receptor, type II (TGFβRII) in the LAC cell line, A549, and its effects on cell proliferation, invasion and metastasis were examined. Three specific small interfering RNAs (siRNAs) designed for targeting human TGFβRII were transfected into A549 cells. The expression of TGFβRII was detected by Western blot analysis. Cell proliferation was measured by MTT and clonogenic assays. Cell apoptosis was assessed by flow cytometry. The invasion and metastasis of A549 cells were investigated using the wound healing and Matrigel invasion assays. The expression of PI3K, phosphorylated Smad2, Smad4, Akt, Erk1/2, P38 and MMPs was detected by Western blot analysis. The TGFβRII siRNA significantly reduced the expression of TGFβRII in A549 cells. The knockdown of TGFβRII in A549 cells resulted in the suppression of cell proliferation, invasion and metastasis and induced cell apoptosis. In addition to the Smad-dependent pathway, independent pathways including the Erk MAPK, PI3K/Akt and p38 MAPK pathways, as well as the expression of MMPs and VEGF, were inhibited. In conclusion, TGF-β signaling is required for LAC progression. Therefore, the blockade of this signaling pathway by the down-regulation of TGFβRII using SiRNA may provide a potential gene therapy for LAC.

USP2a Supports Metastasis by Tuning TGF-β Signaling

TGF-β has been demonstrated to promote tumor metastasis, and the regulatory mechanisms are poorly understood. Here, we report the role of USP2a in promoting metastasis by facilitating TGF-β-triggered signaling. USP2a interacts with TGFBR1 and TGFBR2 upon TGF-β stimulation and removes K33-linked polyubiquitin chains from Lys502 of TGFBR1, promoting the recruitment of SMAD2/3. Simultaneously, TGFBR2 phosphorylates Ser207/Ser225 of USP2a, leading to the disassociation of SMAD2/3 from TGFBR1. The phosphorylation of USP2a and SMAD2 is positively correlated in human tumor biopsies, and USP2a is hyper-phosphorylated in lung adenocarcinomas with lymph node invasion. Depletion or pharmacologic inhibition of USP2a dampens TGF-β-triggered signaling and metastasis. Our findings have characterized an essential role of USP2a as a potential target for treatment of metastatic cancers.

Lipopolysaccharide-induced toll-like receptor 4 signaling in esophageal squamous cell carcinoma promotes tumor proliferation and regulates inflammatory cytokines expression

Emerging evidence suggests toll-like receptor 4 (TLR4) signaling contributes to cancer development and progression. However, the consequences of signaling via the TLR4 pathway in esophageal squamous cell carcinoma (ESCC) are still unclear. Here, we investigated the impact of Lipopolysaccharide (LPS)-induced TLR4 signaling on ESCC cell proliferation, inflammatory cytokines expression, and downstream molecular mechanisms. Seventy-eight ESCC and 26 normal esophageal specimens were analyzed by immunohistochemistry, and two cell lines (Eca-109 and TE-1) were used for in vitro studies. LPS, a natural agonist of TLR4, was used to activate TLR4 signaling. The effects of LPS-TLR4 signaling on cell proliferation and inflammatory cytokines regulation were examined. Specific inhibitors of mitogen-activated protein kinase (MAPK) (extracellular regulated protein kinase [ERK] and p38) signaling pathways were used to investigate the role of each pathway in LPS-TLR4 signaling. TLR4 protein was increased in ESCC tumor tissues compared with the adjacent normal tissues. TLR4 over-expression was significantly correlated with tumor differentiation grade, lymph node metastasis, and UICC stage. LPS-induced activation of TLR4 signaling promoted cancer cell proliferation, increased production of proinflammatory or immunosuppressive cytokines TNF-α, TGF-β and inhibited the anti-inflammatory cytokine IL-10. LPS-TLR4 signaling was associated with the activation of ERK and p38 MAPK signaling pathways. Further inactivation of the two pathways by specific inhibitors attenuated cell proliferation and inflammatory cytokines expression induced by LPS. Our results indicate that LPS-TLR4 signaling in cancer cells contributes to the progression of human ESCC.

Use of a Pedicled Omental Flap in the Treatment of Chest Wall Tuberculosis

The most effective way to treat the chest wall tuberculosis is to fill the residual space with a muscle flap after complete resection of the lesion. However, in some situations a muscle flap cannot be used. The greater omentum has been widely used for reconstruction and the treatment of infections. We describe our technique of using a pedicled omental transposition flap in the management of chest wall tuberculosis for closing the dead space created by excision of the lesion.

A Novel Tracheobronchial Reconstruction for Right Upper Lung Carcinoma Involving the Lower Trachea: Preliminary Results

BACKGROUND We developed a novel technique for tracheobronchial reconstruction after resection of carcinoma of the right upper lung involving the right main bronchus and lower trachea. Preliminary results of the technique are reported. METHODS Between December 2007 and October 2011, 9 patients underwent treatment with our new technique. The right upper lobe was resected together with the involved right main bronchus and right lateral wall of the lower trachea. Closure of the trachea was started at the level of the carina and continued upward, leaving an oval opening at the upper end of the tracheal defect, to which the bronchus intermedius was reimplanted. The sutured lower trachea became the extension of the left main bronchus. RESULTS The procedure was completed successfully in all 9 patients. Two patients underwent partial carinal resection, 2 underwent replacement of the superior vena cava by interposition graft, 2 underwent partial resection of the superior vena cava, and 1 underwent partial resection of the esophageal wall. There were no perioperative deaths. No major complications, including dehiscence, stenosis, and adult respiratory distress syndrome, were observed. Arrhythmia occurred in 2 patients, and vocal cord paresis and pneumonia occurred in 1 patient. One patient died 31 months after operation, and 1 patient was lost to follow-up 28 months after operation, without tumor recurrence. The other 7 are alive to date. CONCLUSIONS Despite this being a small series and short follow-up, this tracheobronchial reconstruction shows encouraging preliminary results with low mortality and morbidity, and could be an alternative to other methods for the treatment of carefully selected patients with advanced carcinoma of the right upper lobe.

Modular 3-cm uniportal video-assisted thoracoscopic left upper lobectomy with systemic lymphadenectomy

Uniportal video-assisted thoracoscopic lobectomy for non-small-cell lung cancer is accepted worldwide, with incisions ranging from 4 to 6 cm. We believed in less invasive and more precise that uniportal video-assisted thoracoscopic lobectomy could be. Therefore, we performed modular uniportal thoracoscopic lobectomy with systemic lymphadenectomy on left upper lobe using a 3-cm-diameter port. And the modular surgical route was arranged in seven modules. Anesthesia, patient positioning and instruments play an important role in the surgery. From October 2014 to June 2015, 96 patients underwent this modular surgery and all patient were discharged uneventfully with no postoperative deaths. Compared with multi-port VATS, the operation time were longer than multiport video-assisted thoracoscopic surgery (VATS) (164.70±12.50 vs. 160.70±11.60 min, P>0.05), and the mean lymphadenectomy station was 6.00±0.77, and the mean lymphadenectomy number was 17.58±5.33. There is no significant difference on lymphadenectomy. Thus, modular uniportal video-assisted thoracoscopic lobectomy with systemic lymphadenectomy on left upper lobe using a 3-cm-diameter port is a safe, feasible, and less painful technique for select patients with lung disease.

Application of pulmonary venoplasty in the surgical treatment of lung cancer

SummaryPresented in this study were three cases of lung cancer undergoing pulmonary venoplasty. In the 3 patients with central type of carcinoma of lung involving pulmonary vein, the main branch of right superior pulmonary vein and the distal end of the superior-lobe vein were occluded. The root part of the vein of right-middle lobe, plus part of vessel of of right superior vein was resected. The right superior vein was reconstructed by continuous 6-0 Prolene sutures. After the operation, the reconstructed was patent and the surgical margin was tumor-free. Postoperatively, clinical manifestations and plain chest films did not show any signs of venous blockade. The patients were discharged healed 3 weeks after the operation. The technical details of the surgery were presented, the improvements on the basis of traditional methods were discussed and its clinical application was evaluated. It is concluded that pulmonary venoplasty is a safe and feasible operation. Further improvement of the surgery will help conserve more lung tissue and benefit more patients because of expanded indications.Presented in this study were three cases of lung cancer undergoing pulmonary venoplasty. In the 3 patients with central type of carcinoma of lung involving pulmonary vein, the main branch of right superior pulmonary vein and the distal end of the superior-lobe vein were occluded. The root part of the vein of right-middle lobe, plus part of vessel of of right superior vein was resected. The right superior vein was reconstructed by continuous 6-0 Prolene sutures. After the operation, the reconstructed was patent and the surgical margin was tumor-free. Postoperatively, clinical manifestations and plain chest films did not show any signs of venous blockade. The patients were discharged healed 3 weeks after the operation. The technical details of the surgery were presented, the improvements on the basis of traditional methods were discussed and its clinical application was evaluated. It is concluded that pulmonary venoplasty is a safe and feasible operation. Further improvement of the surgery will help conserve more lung tissue and benefit more patients because of expanded indications.