Wen-Qian Zhang

YAP promotes erlotinib resistance in human non-small cell lung cancer cells

Yes-associated protein (YAP) is a main mediator of the Hippo pathway, which promotes cancer development. Here we show that YAP promotes resistance to erlotinib in human non-small cell lung cancer (NSCLC) cells. We found that forced YAP overexpression through YAP plasmid transfection promotes erlotinib resistance in HCC827 (exon 19 deletion) cells. In YAP plasmid-transfected HCC827 cells, GTIIC reporter activity and Hippo downstream gene expression of AREG and CTGF increased significantly (P<0.05), as did ERBB3 mRNA expression (P<0.05). GTIIC reporter activity, ERBB3 protein and mRNA expression all increased in HCC827 erlotinib-resistance (ER) cells compared to parental HCC827 cells. Inhibition of YAP by small interfering RNA (siRNA) increased the cytotoxicity of erlotinib to H1975 (L858R+T790M) cells. In YAP siRNA-transfected H1975 cells, GTIIC reporter activity and downstream gene expression of AREG and CTGF decreased significantly (P<0.05). Verteporfin, YAP inhibitor had an effect similar to that of YAP siRNA; it increased sensitivity of H1975 cells to erlotinib and in combination with erlotinib, synergistically reduced migration, invasion and tumor sphere formation abilities in H1975 cells. Our results indicate that YAP promotes erlotinib resistance in the erlotinib-sensitive NSCLC cell line HCC827. Inhibition of YAP by siRNA increases sensitivity of erlotinib-resistant NSCLC cell line H1975 to erlotinib.

Efficacy of EGFR Tyrosine Kinase Inhibitors in Non-Small-Cell Lung Cancer Patients with/without EGFR-Mutation: Evidence Based on Recent Phase III Randomized Trials

Background EGFR mutation might be a predictive factor for applying EGFR-tyrosine kinase inhibitors (EGFR-TKIs, including gefitinib, erlotinib and afatinib) in non-small-cell lung cancer (NSCLS) patients. Thus, it is necessary to pool previous trials to compare the effect of EGFR-TKIs versus cytotoxic chemotherapy in EGFR mutation positive (mut+) and negative (mut−) patients. Material/Methods This study identified 8 first-line and 9 second-line phase III trials in databases. Hazard ratio (HR) was pooled to assess the risk of progression-free survival (PFS), and overall survival (OS), while odds ratio (OR) was pooled to assess objective response, disease control, and toxicity of EGFR-TKIs verses chemotherapy. Results In EGFR mut+ patients, EGFR-TKIs were associated with significantly lower risk of disease progression in the first-line setting, but this trend was only observed in the gefitinib group, not in the erlotinib group in the second-line setting. In EGFR mut− patients, gefitinib and erlotinib had significantly higher risk of disease progression in first-line and second-line setting, respectively. Compared with chemotherapy, the effects of EGFR-TKIs on OS in both first-line and second-line settings were not evident. Regarding toxicity, EGFR-TKIs had significantly higher risk of rash and lower hematological toxicity compared with chemotherapy. Conclusions All of the 3 EGFR-TKIs and gefitinib alone regimens had better effects in prolonging PFS in EGFR mut+ patients in first-line and second-line setting, respectively, but chemotherapy seemed more effective in EGFR mut− patients than EGFR-TKIs. Therefore, accurate identification of EGFR mutation status is useful to decide on an appropriate regimen for treatment of NSCLC patients.

Targeting YAP in malignant pleural mesothelioma

Malignant mesothelioma is an aggressive cancer that is resistant to current therapy. The poor prognosis of mesothelioma has been associated with elevated Yes‐associated protein (YAP) activity. In this study, we evaluated the effect of targeting YAP in mesothelioma. First, we comprehensively studied YAP activity in five mesothelioma cell lines (211H, H2052, H290, MS‐1 and H2452) and one normal mesothelial cell line (LP9). We found decreased phospho‐YAP to YAP protein ratio and consistently increased GTIIC reporter activity in 211H, H2052 and H290 compared to LP9. The same three cell lines (IC50s < 1 μM) were more sensitive than LP9 (IC50 = 3.5 μM) to the YAP/TEAD inhibitor verteporfin. We also found that verteporfin significantly reduced YAP protein level, mRNA levels of YAP downstream genes and GTIIC reporter activity in the same three cell lines, indicating inhibition of YAP signaling by verteporfin. Verteporfin also impaired invasion and tumoursphere formation ability of H2052 and H290. To validate the effect of specific targeting YAP in mesothelioma cells, we down‐regulated YAP by siRNA. We found siYAP significantly decreased YAP transcriptional activity and impaired invasion and tumoursphere formation ability of H2052 and H290. Furthermore, forced overexpression of YAP rescued GTIIC reporter activity and cell viability after siYAP targeting 3′UTR of YAP. Finally, we found concurrent immunohistochemistry staining of ROCK2 and YAP (P < 0.05). Inhibition of ROCK2 decreased GTIIC reporter activity in H2052 and 211H suggesting that Rho/ROCK signaling also contributed to YAP activation in mesothelioma cells. Our results indicate that YAP may be a potential therapeutic target in mesothelioma.

YAP1 regulates ABCG2 and cancer cell side population in human lung cancer cells

A small population of cancer cells called cancer-initiating cells or cancer stem cells (CSCs) are involved in drug resistance, metastasis, and cancer relapse. Finding pathways that regulate CSC is very important for clinical therapy. ATP-binding cassette sub-family G member 2 (ABCG2) plays a role in side population (SP) cell formation and contributes to chemotherapy resistance in common forms of cancer. Yes-associated protein 1 (YAP1) is a major transcriptional effector of the Hippo pathway, which plays important roles in organ size control and tumorigenesis. In this study, we found ABCG2 and YAP1 were both overexpressed in lung cancer SP cells. Disruption of YAP1 expression by siRNA attenuated the expression of ABCG2 transcript and significantly reduced the percentage of SP cells and sphere formation in lung cancer cells. Overexpression of YAP1 in lung cancers led to an increase in ABCG2 expression and increased the percentage of SP cells. However, overexpression of YAP1 in purified non-SP cells did not increase ABCG2 expression and the percentage of SP cells, which may be due to the inhibition of YAP activity through phosphorylation. YAP1 directly transcriptionally regulated ABCG2 by binding to the promoter of ABCG2. Moreover, the YAP1 inhibitor verteporfin and YAP1 siRNA downregulated ABCG2 level through inhibition of YAP1 in lung cancer cells and sensitized them to the chemotherapy drug doxorubicin. Our study adds a new function for YAP1 that may be relevant to drug resistance and cancer therapy through regulation of ABCG2 and side population cell formation in lung cancer.

Application of Extracorporeal Membrane Oxygenation in Giant Bullae Resection

A patient with chronic obstructive pulmonary disease and lung bullae was admitted to our hospital. He suffered respiratory failure and was given mechanical ventilation. However, the bullae became more and more large and compressed the lungs on both sides. We managed extracorporeal membrane oxygenation (ECMO) to maintain the patients blood oxygenation, and performed bullae resection surgery successfully. The patients pulmonary function recovered gradually after the operation and he returned home. In our experience with this case, ECMO can be used in bullae resection.

A tuberculous abscess of the chest wall in a renal allograft recipient

Tuberculous abscess of the chest wall is a rare localization of tuberculosis. We herein report a case of tuberculosis of the chest wall on a renal allograft recipient and provide discussion on optimal therapeutic management.

Erratum to the significance of perioperative coagulation and fibrinolysis related parameters after lung surgery for predicting venous thromboembolism: a prospective, single center study

Background The high incidence of venous thromboembolism (VTE) has been perceived in post thoracic surgery patients. However, the significance of perioperative coagulation and fibrinolysis related parameters after lung surgery for VTE predicting is not clear. To investigate that, we conducted a prospective single center study. Methods A total of 111 patients undergoing lung surgery were enrolled in this study, included 52 primary lung cancer patients and 59 benign lung disease patients from July 2016 to March 2017. Preoperative and postoperative days 1, 3, and 5 coagulation and fibrinolysis related parameters were tested, including antithrombin (AT), fibrinogen degradation product (FDP), prothrombin time (PT), prothrombin time activity (PA), prothrombin time ratio (PR), international normalized ratio (INR), activated partial thromboplastin time (APTT), plasma fibrinogen (FBG), thrombin time (TT) and D-Dimer. The Doppler ultrasonography was performed before and after surgery for deep venous thrombosis (DVT) confirmation. Patients with new postoperative DVT, unexplained dyspnea, hemoptysis, chest pain, or high Caprini score (≥9) were received further computer tomography pulmonary angiography (CTPA) for pulmonary embolism (PE). We used the area under receiver-operating-characteristic (ROC) curve to discriminate patients between those who developed VTE and those who did not. Single factor analysis was utilized to define risk factors associated with VTE. Results The overall incidence of VTE was 16.2% (18/111). The incidence of VTE in primary lung cancer patients was 23.1% (12/52), much higher than that in benign lung diseases 10.2% (6/59), but did not reach statistical significance (P=0.066). Among 18 VTE patients, 83.3% was DVT, 16.7% was DVT + PE and 72.2% was muscular veins of the calf thrombosis. D-Dimer was much higher in VTE group than that in non-VTE group preoperatively and at postoperative days 1, 3 (0.64±0.24 vs. 0.33±0.06, P=0.007; 3.14±0.75 vs. 1.51±0.09, P=0.005, and 1.88±0.53 vs. 0.76±0.05, P=0.001, respectively). And the ROC curve areas of preoperative and postoperative days 1, 3 of D-Dimer were 0.70, 0.71 and 0.74, respectively. And FDP was much higher in VTE group than that in non-VTE group at postoperative day 3 (6.78±1.43 vs. 3.79±0.15, P=0.004). But AT, PT, PA, PR, INR, APTT, FBG and TT there were no significantly difference. Conclusions The overall incidence of VTE after lung surgery was 16.2%. The patients with preoperative high D-Dimer should receive VTE prophylaxis.

Expression of TGF-beta receptor 1 and Smads in the tissues of primary spontaneous pneumothorax

Background Primary spontaneous pneumothorax (PSP) is a common disease which is often caused by the rupture of bullae in the lungs. The underlying pathogenesis of PSP remains unclear. Some molecules may be involved in the development of PSP potentially. The aim of this study was to investigate the expression of TGF-beta receptor 1 (TβR1), Smad2, Smad3 and Smad4 in the resected bullae of patients with PSP. Methods From May 2015 to May 2016, 34 patients with PSP underwent video-assisted thoracoscopic surgery (VATS) bullectomy. Immunohistochemistry was performed to identify the expression of TβR1, Smad2, Smad3 and Smad4 in the resected pulmonary bullae tissues. The levels of these cytokines were calculated by immunoreactivity scoring system (IRS). Ten patients without pneumothorax associated disease were selected as the control group. Results The analysis showed that the expression levels of TβR1, Smad2 and Smad4 were significantly higher in bullae tissues of patients with PSP than that in normal lung tissues (P=0.012, 0.031, 0.000 respectively). There was no significant difference between the expression level of Smad3 in bullae tissue of PSP patients and that in normal lung tissues of the control group (P=0.140). However, the absolute quantity of Smad3 expression in PSP bullae tissues was (4.2529±1.7193), scored by the IRS, which is higher than that in the control lung tissues (3.2600±2.2132). Also, the expression of TβR1, Smad2, Smad3 and Smad4 were not showed correlation with the clinical characteristics of PSP patients, such as age, sex, body mass index (BMI), recurrence and side of pneumothorax. Conclusions TβR1, Smad2 and Smad4 highly expressed in bullae tissues of PSP patients. Our findings suggested that TβR1, Smad2 and Smad4 may be related to the development of PSP bullae.

Inhibition of yes‐associated protein down‐regulates PD‐L1 (CD274) expression in human malignant pleural mesothelioma

Although tumour PD‐L1 (CD274) expression had been used as a predictive biomarker in checkpoint immunotherapy targeting the PD1/PD‐L1 axis in various cancers, the regulation of PD‐L1 (CD274) expression is unclear. Yes‐associated protein (YAP), an important oncogenic protein in Hippo signalling pathway, reportedly promotes cancer development. We investigated whether inhibition of YAP down‐regulates PD‐L1 (CD274) in human malignant pleural mesothelioma (MPM). Western blotting showed that 2 human MPM cell lines (H2052 and 211H) had increased PD‐L1 protein expression compared to H290, MS‐1 and H28 cells. In H2052 and 211H cells, PD‐L1 mRNA expression was significantly increased compared to other MPM cell lines; YAP knockdown by small interfering RNA decreased PD‐L1 protein and mRNA expression. Forced overexpression of the YAP gene increased PD‐L1 protein expression in H2452 cells. Chromatin immunoprecipitation (ChIP) assay showed the precipitation of PD‐L1 enhancer region encompassing 2 putative YAP‐TEAD‐binding sites in H2052 cells. We found that, in human MPM tissue microarray samples, YAP and PD‐L1 concurrently expressed in immunohistochemistry stain (n = 70, P < .05, chi‐square). We conclude that PD‐L1 is correlated with YAP expression, and inhibition of YAP down‐regulates PD‐L1 expression in human MPM. Further study of how YAP regulates PD‐L1 in MPM is warranted.

Transfer of multiple loci of donor's genes to induce recipient tolerance in organ transplantation

Donor organ rejection remains a significant problem. The present study aimed to assess whether transferring a donors major histocompatibility complex (MHC) genes to the recipient could mitigate rejection in organ transplantation. Seven loci of MHC genes from donor mice were amplified and ligated into vectors; the vectors either contained one K locus, seven loci or were empty (control). The vectors were subsequently injected into the thymus of recipients (in heterotransplants, recipient rats received the vector containing one K locus), following which donor mouse hearts were transplanted. Following the transplantation of allograft and heterograft, electrocardiosignals were viable for a significantly longer duration in recipient mice and rats receiving the donor histocompatibility-2 complex (H-2)d genes compared with those in controls, and in mice that received seven vectors compared with those receiving one vector. Mixed lymphocyte cultures containing cells from these recipients proliferated significantly less compared with mixed lymphocyte cultures containing controls. Also, hearts from H-2d genes-treated recipients demonstrated less lymphocyte infiltration and necrosis compared with the control recipient. The present study concluded that allograft and heterograft rejection may be mitigated by introducing the donors MHC into the recipient; transferring seven loci has been demonstrated to be more effective than transferring one locus.