Therapeutic Potential of Regorafenib in Cisplatin-Resistant Bladder Cancer with High Epithelial-Mesenchymal Transition and Stemness Properties.

Bladder cancer is becoming one of the most common malignancies across the world. Although treatment strategy has been continuously improved, which has led to cisplatin-based chemotherapy becoming the standard medication, cancer recurrence and metastasis still occur in a high proportion of patients because of drug resistance. The high efficacy of regorafenib, a broad-spectrum kinase inhibitor, has been evidenced in treating a variety of advanced cancers. Hence, this study investigated whether regorafenib could also effectively antagonize the survival of cisplatin-resistant bladder cancer and elucidate the underlying mechanism. Two types of cisplatin-resistant bladder cancer cells, T24R1 and T24R2, were isolated from T24 cisplatin-sensitive bladder cancer cells. These cells were characterized, and T24R1- and T24R2-xenografted tumor mice were created to examine the therapeutic efficacy of regorafenib. T24R1 and T24R2 cells exhibited higher expression levels of epithelial-mesenchymal transition (EMT) and stemness markers compared to the T24 cells, and regorafenib could simultaneously inhibit the viability and the expression of EMT/stemness markers of both T24R1 and T24R2 cells. Moreover, regorafenib could efficiently arrest the cell cycle, promote apoptosis, and block the transmigration/migration capabilities of both types of cells. Finally, regorafenib could significantly antagonize the growth of T24R1- and T24R2-xenografted tumors in mice. These results demonstrated the therapeutic efficacy of regorafenib in cisplatin-resistant bladder cancers. This study, thus, provides more insights into the mechanism of action of regorafenib and demonstrates its great potential in the future treatment of cisplatin-resistant advanced bladder cancer patients.

Modulation of mitochondrial apoptosis by ß2-adrenergic receptor blockage in colorectal cancer after radiotherapy: an in-vivo and in-vitro study.

Colorectal cancer (CRC) is one of the leading causes of malignancy-related deaths worldwide. Radiotherapy is often combined with surgery to treat patients with more advanced CRC. Despite impressive initial clinical responses, radiotherapy resistance is the main reason for most treatment failures in colorectal cancer. The G protein-coupled adrenergic receptor (AR) has shown to involve in the development and radiotherapy resistance of CRC. The ß2-AR blockage (ICI-118,551) can use to inhibit the progression of CRC through downregulating EGFR-Akt-ERK1/2 signaling. Since catecholamines-activated the G protein-coupled AR activation has been shown to result in radioresistant, co-treatment with both ß2-AR blockage and radiation may be improved the clinical outcome of CRC. We demonstrated that selective ß2-AR blockage, but not selective ß1-AR blockage, significantly enhanced radiation-induced apoptosis in CRC cells with wild-type p53 in vitro. The molecular mechanism of the apoptotic pathway was possibly triggered by a change in the mitochondrial membrane permeability and release of cytosolic cytochrome C through phospho-P53 mitochondrial translocation. We also found that a P53 knockout in the HCT116 cells was correlated with reversing ß2-AR blockage-mediated apoptosis induction after radiation treatment. Furthermore, the ß2-AR blockage significantly inhibited CRC cell-xenograft growth in vivo. Our study suggests that ß2-AR blockage may be used as adjunct agent for improving the clinical outcomes of CRC following radiotherapy by inducing apoptosis in CRC cells.

The impact of sarcopenia on overall survival in patients with pan-RAS wild-type colorectal liver metastasis receiving hepatectomy.

Sarcopenia has been associated with conventional chemotherapy-related toxicity, postoperative complications and poor overall survival in patients with genotype-unselected metastatic colorectal cancer (mCRC). This study aimed to evaluate the prognostic implications of sarcopenia and its change after perioperative cetuximab plus doublet chemotherapy and hepatectomy in patients with RAS wild-type colorectal liver metastasis (CRLM). Patients with CRLM from 2007 to 2018 in Chang Gung Research Database were retrospectively analyzed. Baseline characteristics as well as skeletal muscle index (SMI) at baseline and dynamic changes after interventions were collected. A multivariate Cox proportional hazard model was used to evaluate the effect of each parameter on overall survival (OS), and the Kaplan-Meier method was used to establish survival curves. A two-sided p value < 0.05 was considered statistically significance. Of 214 RAS wild-type mCRC patients who received both cetuximab and doublet chemotherapy, 77 who received upfront or subsequent hepatectomy were included in this study. The median follow-up time was 2.3 years. The rate of sarcopenia was higher in the patients who received neoadjuvant cetuximab-containing regimens than in those who received upfront hepatectomy (95% versus 63%, p = 0.001). Increased SMI after perioperative systemic therapy remained independently associated with better OS in multivariate analysis [hazard ratio (HR) = 0.27/10% increase, p = 0.013). The patients with sarcopenia had a trend of worse OS than those without sarcopenia (median OS: 4.5 versus 3.6 years, log-rank p = 0.282). Improvement in sarcopenia ([SMI after intervention - initial SMI]/initial SMI × 100%) is an important prognostic factor for OS. Future research is warranted to investigate direct interventions for sarcopenia and the impact on OS.

The cancer stemness inhibitor napabucasin suppresses small cell lung cancer growth through SOX2 expression.

Small cell lung cancer (SCLC) is a high-grade malignancy of neuroendocrine origin characterized by aggressive cell growth and a poor survival rate of patients. Currently, the treatment options for SCLC remain limited despite platinum-based chemotherapy. Systemic chemotherapy is effective for SCLC, but most patients eventually acquire drug resistance, which leads to treatment failure. Stemness-high cancer cells show characteristics of advanced tumorigenesis and metastasis and have high potential in promoting treatment resistance and disease relapse. Napabucasin (BBI608), a novel small-molecule drug targeting on signal transducer and activator of transcription 3 (STAT3), was shown to suppress the progression and metastasis of stemness-high cancer stem cells in various cancers. Here, we demonstrated that napabucasin significantly decreased viability and colony formation and induced the arrest of S-phase cell cycle and apoptosis in cisplatin-resistant SCLC cells. Findings from mechanistic studies further indicated that napabucasin directly downregulated the expression of SOX2 in cisplatin-resistant SCLC cells; however, dysfunctional SOX2 expression in SCLC cells was associated with interference in the napabucasin-mediated reduction of cell viability. In contrast, napabucasin-induced viability reduction was restored in these cells when SOX2 expression was upregulated. Furthermore, napabucasin significantly inhibited cisplatin-resistant SCLC cell xenograft growth in vivo by downregulating SOX2 and inducing apoptosis. These data demonstrate that napabucasin may be a novel drug for the clinical treatment of cisplatin-resistant SCLC.

Inhibition of Neddylation Suppresses Osteoclast Differentiation and Function In Vitro and Alleviates Osteoporosis In Vivo.

Neddylation, or the covalent addition of NEDD8 to specific lysine residue of proteins, is a reversible posttranslational modification, which regulates numerous biological functions; however, its involvement and therapeutic significance in osteoporosis remains unknown. Our results revealed that during the soluble receptor activator of nuclear factor-κB ligand (sRANKL)-stimulated osteoclast differentiation, the neddylation and expression of UBA3, the NEDD8-activating enzyme (NAE) catalytic subunit, were dose- and time-dependently upregulated in RAW 264.7 macrophages. UBA3 knockdown for diminishing NAE activity or administering low doses of the NAE inhibitor MLN4924 significantly suppressed sRANKL-stimulated osteoclast differentiation and bone-resorbing activity in the macrophages by inhibiting sRANKL-stimulated neddylation and tumor necrosis factor receptor-associated factor 6 (TRAF6)-activated transforming growth factor-ß-activated kinase 1 (TAK1) downstream signaling for diminishing nuclear factor-activated T cells c1 (NFATc1) expression. sRANKL enhanced the interaction of TRAF6 with the neddylated proteins and the polyubiquitination of TRAF6's lysine 63, which activated TAK1 downstream signaling; however, this process was inhibited by MLN4924. MLN4924 significantly reduced osteoporosis in an ovariectomy- and sRANKL-induced osteoporosis mouse model in vivo. Our novel finding was that NAE-mediated neddylation participates in RANKL-activated TRAF6-TAK1-NFATc1 signaling during osteoclast differentiation and osteoporosis, suggesting that neddylation may be a new target for treating osteoporosis.

Perioperative Complications and Oncologic Outcomes after Radical Cystectomy in End-Stage Renal Disease Patients with Bladder Cancer Obtained Using a Standardized Reporting System.

Background: We investigated the use of a standardized reporting system to study perioperative complications and oncologic outcomes after radical cystectomy in end-stage renal disease (ESRD) patients with bladder cancer. Methods: We reviewed retrospective outcomes in 141 ESRD patients with bladder cancer who underwent radical cystectomy between 2004 and 2015. Complications were graded using the Clavien−Dindo classification system with 0−2 classified as "No Major Complications" and Clavien 3−5 as "Major Complications". Low-volume surgeons were classified as those performing fewer than nine cases during the study. Fisher's exact test along with the chi-squared test, two-tailed t tests, logistic regression, and the Cox proportional hazard model were used to evaluate all clinically meaningful covariates. Results: Ninety-nine (99, 70.2%) patients had no major complications, and forty-two (29.8%) patients had major complications. Patients in the major complications group were older, had a higher Charlson comorbidity index (CCI), and had a longer hospitalization duration than those in the no major complications group (all, p < 0.05). Major complications were also more common when the procedure was performed by low-volume surgeons (p = 0.003). In multivariate logistic regression models, CCI ≥ 5 (p = 0.006) and low-volume surgeon (p = 0.004) were independent predictors of major complications. According to multivariate analysis with the Cox hazards regression, male sex, age > 70 years, CCI ≥ 5, bladder cancer stage ≥ 3, lymphovascular invasion, and experiencing major complications were significant poor prognostic factors for overall survival (all, p < 0.05). Conclusions: Accurate reporting of complications is necessary for preoperative counseling, identifying modifiable risk factors, and planning risk mitigation strategies. High comorbidity and low-volume surgeons were interrelated as notable risk factors for major complications. In addition to tumor-related factors, male sex, older age, and major complications significantly influence overall survival.

N-acetylcysteine alleviates fine particulate matter (PM2.5)-induced lung injury by attenuation of ROS-mediated recruitment of neutrophils and Ly6Chigh monocytes and lung inflammation.

BACKGROUND: Exposure to particulate matter (PM) may contribute to lung inflammation and injury. The therapeutic effect of N-acetylcysteine (NAC), a well-known antioxidant, with regards to the prevention and treatment of fine PM (PM2.5)-induced lung injury is poorly understood. This study aimed to determine the effect of PM2.5 on the recruitment of neutrophils and Ly6Chigh monocytes into lung alveoli and the production of proinflammatory proteins by stimulating the generation of reactive oxygen species (ROS), and to investigate the therapeutic effect of NAC on PM2.5-induced lung injury. METHODS: C57BL/6 mice were exposed to a single administration of PM2.5 (200 µg/100 µl/mouse) or phosphate-buffered saline (control) via intratracheal instillation. The mice were injected intratracheally via a microsprayer aerosolizer with NAC (20 or 40 mg/kg) 1 h before PM2.5 instillation and 24 h after PM2.5 instillation. Total protein, VEGF, IL-6, and TNF-α in bronchoalveolar lavage fluid (BALF) were measured. Oxidative stress was evaluated by determining levels of malondialdehyde (MDA) and nitrite in BALF. Flow cytometric analysis was used to identify and quantify neutrophils and Ly6Chigh and Ly6Clow monocyte subsets. RESULTS: Neutrophil count, total protein, and VEGF content in BALF significantly increased after PM2.5 exposure and reached the highest level on day 2. Increased levels of TNF-alpha, IL-6, nitrite, and MDA in BALF were also noted. Flow cytometric analysis showed increased recruitment of neutrophils and Ly6Chigh, but not Ly6Clow monocytes, into lung alveoli. Treatment with NAC via the intratracheal spray significantly attenuated the recruitment of neutrophils and Ly6Chigh monocytes into lung alveoli in PM2.5-treated mice in a dose-dependent manner. Furthermore, NAC significantly attenuated the production of total protein, VEGF, nitrite, and MDA in the mice with PM2.5-induced lung injury in a dose-dependent manner. CONCLUSION: PM2.5-induced lung injury caused by the generation of oxidative stress led to the recruitment of neutrophils and Ly6Chigh monocytes, and production of inflammatory proteins. NAC treatment alleviated PM2.5-induced lung injury by attenuating the ROS-mediated recruitment of neutrophils and Ly6Chigh monocytes and lung inflammation.

Different impacts of common risk factors associated with thrombocytopenia in patients with hepatitis B virus and hepatitis C virus infection.

BACKGROUND: Thrombocytopenia is a common extrahepatic manifestation in chronic liver disease. However, there have been rare studies of impacts of risk for hepatitis C virus-associated thrombocytopenia (HCV-TP) and hepatitis B virus-associated thrombocytopenia (HBV-TP). The aim of this study is to evaluate different impacts of risk factors for HCV-TP and HBV-TP. METHODS: We retrospectively collected 1803 HCV patients and 1652 HBV patients to examine the risk factors for time to moderate and severe thrombocytopenia (platelet counts <100 × 109/L and <50 × 109/L, respectively) by Cox proportional hazards models. Moreover, we prospectively enrolled 63 HCV-TP patients, 11 HBV-TP patients, and 27 HCV controls to detect specific antiplatelet antibodies by enzyme-linked immunosorbent assay and analyze their effects. RESULTS: Prevalence of platelet <100 × 109/L was 11.86% and 6.35% in HCV and HBV patients without cancer history, respectively. HCV-to-HBV incidence rate ratio for thrombocytopenia was 6.95. Initial thrombocytopenia was the most significant risk factor for HCV-TP and HBV-TP regardless of thrombocytopenia severity. Splenomegaly and cirrhosis were significant risk factors for moderate, but not severe HCV-TP. Hyperbilirubinemia was an important moderate and severe HBV-TP risk factor. Antiplatelet antibodies were correlated with HCV-TP severity, of which anti-glycoprotein IIb/IIIa antibody being associated with smaller spleen size. The antiplatelet autoantibody might contribute to thrombocytopenia either independently or with splenomegaly as the important risk in HCV-TP patients without advanced cirrhosis. CONCLUSION: HCV was associated with higher thrombocytopenia incidence than HBV. Thrombocytopenia risk factors varied with virus type and severity. Different management for HCV-TP and HBV-TP was suggested.

Roles of lung-recruited monocytes and pulmonary Vascular Endothelial Growth Factor (VEGF) in resolving Ventilator-Induced Lung Injury (VILI).

Monocytes and vascular endothelial growth factor (VEGF) have profound effects on tissue injury and repair. In ventilator-induced lung injury (VILI), monocytes, the majority of which are Ly6C+high, and VEGF are known to initiate lung injury. However, their roles in post-VILI lung repair remain unclear. In this study, we used a two-hit mouse model of VILI to identify the phenotypes of monocytes recruited to the lungs during the resolution of VILI and investigated the contributions of monocytes and VEGF to lung repair. We found that the lung-recruited monocytes were predominantly Ly6C+low from day 1 after the insult. Meanwhile, contrary to inflammatory cytokines, pulmonary VEGF decreased upon VILI but subsequently increased significantly on days 7 and 14 after the injury. There was a strong positive correlation between VEGF expression and proliferation of alveolar epithelial cells in lung sections. The expression pattern of VEGF mRNA in lung-recruited monocytes was similar to that of pulmonary VEGF proteins, and the depletion of monocytes significantly suppressed the increase of pulmonary VEGF proteins on days 7 and 14 after VILI. In conclusion, during recovery from VILI, the temporal expression patterns of pulmonary growth factors are different from those of inflammatory cytokines, and the restoration of pulmonary VEGF by monocytes, which are mostly Ly6C+low, is associated with pulmonary epithelial proliferation. Lung-recruited monocytes and pulmonary VEGF may play crucial roles in post-VILI lung repair.

The influence of smoking exposure and cessation on penile hemodynamics and corporal tissue in a rat model.

BACKGROUND: While epidemiological studies have clearly documented that smoking cessation significantly enhances sexual health, the underlying mechanism remains largely unknown. Thus, we wished to explore possible mechanisms by using a rat model of smoking-associated erectile dysfunction (ED). METHODS: Forty 8-week old male Sprague-Dawley rats were divided into 4 groups. Ten rats were exposed only to room air (N group). The remaining 30 rats were passively exposed to cigarette smoke over a 12-week period. At the end of 12 weeks, the smoking (S, n=10) group underwent immediate erectile function testing and were sacrificed. The remaining 20 rats were exposed to room air only for 4 (Q4W, n=10) or 8 (Q8W, n=10) weeks and then underwent erectile function testing and sacrifice. Erectile function was evaluated by measuring intracavernous pressure (ICP) and mean arterial pressure (MAP). After blood collection for serum testosterone determination, rats were sacrificed to obtain corporal tissue for immunohistochemistry. RESULTS: Mean ICP/MAP ratio was significantly lower in the S group compared to the N and Q8W groups (0.52±0.11, 0.94±0.05, and 0.94±0.12, respectively, P=0.0189). Smooth muscle/collagen ratio was also significantly lower in the S group compared to the N and Q8W groups (11.8±0.94, 17.5±1.82, and 16.4±0.60, respectively, P=0.0008). Oxidative stress and apoptotic indices were significantly higher in the S group compared to the N and Q8W groups. Neuronal and endothelial nitric oxide synthases were significantly less expressed in the S group compared to the N and Q8W groups. CONCLUSIONS: Smoking cessation is associated with partial recovery of penile hemodynamics in a rat model of smoking associated ED.

Neddylation inhibitor, MLN4924 suppresses angiogenesis in huvecs and solid cancers: in vitro and in vivo study.

Cullin-RING E3 ligases are involved in the ubiquitination of substrates that regulate important biological processes and are a potential therapeutic target in many types of cancer. MLN4924, a small molecule of NEDD8-activating enzyme inhibitor, inactivates CRL by blocking cullin neddylation and has been reported to elicit anti-tumor effect. In this study, In this study, we aimed to investigate the effects of MLN4924 on angiogenesis in human umbilical vascular endothelial cells (HUVECs) and four types of cancer cells. Our results showed that MLN4924 inhibits cell viability and induced apoptosis in HUVECs in a dose-dependent manner. MLN4924 inhibits proliferation and interferes with the cell cycle checkpoint regulators, p21, p27, and phospho-histone H3. Vascular endothelial growth factor (VEGF) treatment increased the level of UBC12 in HUVECs, indicating that neddylation pathway is involved in VEGF-activated angiogenesis. MLN4924 decreased VEGF-activated cell proliferation via neddylation inhibition. MLN4924 inhibited VEGF-activated cell migration, capillary tube formation and VEGF-mediated Erk1/2 activation in HUVECs. We also examined antitumor effect of MLN4924 using xenograft SCID mouse models of four different types of cancer cells. The in vivo results showed MLN4924 inhibited tumor growth in all four types of cancers with decreasing CD31 expression in xenograft tumor. In conclusion, MLN4924 inhibited viability, migration, and VEGF-promoted angiogenic activity in HUVECs; consistently, MLN4924 inhibited tumor growth in four types of cancers with suppression of angiogenesis. These findings provide evidence to develop therapeutic strategy for cancer treatment through anti-angiogenesis through neddylation inhibition.

Honokiol Is a Potential Therapeutic Agent and Has a Synergistic Effect With 5-FU in Human Urothelial Cell Carcinoma Cells.

BACKGROUND/AIM: Honokiol is a biphenolic component of the bark of Magnolia, and has been shown to exert several activities, including anti-depressant, anti-emetic, anti-oxidative, anti-thrombotic, anti-angiogenesis, anti-anxiolytic, anti-inflammatory and anti-tumor effects. MATERIALS AND METHODS: The anti-tumor activities of honokiol and its synergistic effect with 5-fluorouracil (5-FU) in human urothelial cell carcinoma (UCC) cells were investigated. RESULTS: Honokiol significantly suppressed the proliferation of UCC cells in a dose- and time-dependent manner. Moreover, honokiol inhibited the tumorigenesis of UCC cells in vitro. In addition, honokiol induced cell cycle arrest at G0/G1 phase and caused apoptosis of UCC cells through the intrinsic pathway. Importantly, we demonstrated that honokiol potentiated the cytotoxic effect of 5-FU, and displayed a synergistic effect with 5-FU in UCC cells. CONCLUSION: Honokiol causes growth inhibition, tumorigenesis suppression, cell cycle arrest, apoptosis, and importantly has a synergistic effect with 5-FU in human UCC cells. Therefore, this agent displays a therapeutic potential for treating human UCC.

Suppression of Angiogenesis by Targeting Cyclin-Dependent Kinase 7 in Human Umbilical Vein Endothelial Cells and Renal Cell Carcinoma: An In Vitro and In Vivo Study.

Cancer cells rely on aberrant transcription for growth and survival. Cyclin-dependent kinases (CDKs) play critical roles in regulating gene transcription by modulating the activity of RNA polymerase II (RNAPII). THZ1, a selective covalent inhibitor of CDK7, has antitumor effects in several human cancers. In this study, we investigated the role and therapeutic potential of CDK7 in regulating the angiogenic activity of endothelial cells and human renal cell carcinoma (RCC). Our results revealed that vascular endothelial growth factor (VEGF), a critical activator of angiogenesis, upregulated the expression of CDK7 and RNAPII, and the phosphorylation of RNAPII at serine 5 and 7 in human umbilical vein endothelial cells (HUVECs), indicating the transcriptional activity of CDK7 may be involved in VEGF-activated angiogenic activity of endothelium. Furthermore, through suppressing CDK7 activity, THZ1 suppressed VEGF-activated proliferation and migration, as well as enhanced apoptosis of HUVECs. Moreover, THZ1 inhibited VEGF-activated capillary tube formation and CDK7 knockdown consistently diminished tube formation in HUVECs. Additionally, THZ1 reduced VEGF expression in human RCC cells (786-O and Caki-2), and THZ1 treatment inhibited tumor growth, vascularity, and angiogenic marker (CD31) expression in RCC xenografts. Our results demonstrated that CDK7-mediated transcription was involved in the angiogenic activity of endothelium and human RCC. THZ1 suppressed VEGF-mediated VEGFR2 downstream activation of angiogenesis, providing a new perspective for antitumor therapy in RCC patients.

The Deubiquitinating Enzyme Inhibitor PR-619 Enhances the Cytotoxicity of Cisplatin via the Suppression of Anti-Apoptotic Bcl-2 Protein: In Vitro and In Vivo Study.

After chemotherapy for the treatment of metastatic bladder urothelial carcinoma (UC), most patients inevitably encounter drug resistance and resultant treatment failure. Deubiquitinating enzymes (DUBs) remove ubiquitin from target proteins and play a critical role in maintaining protein homeostasis. This study investigated the antitumor effect of PR-619, a DUBs inhibitor, in combination with cisplatin, for bladder UC treatment. Our results showed that PR-619 effectively induced dose- and time-dependent cytotoxicity, apoptosis, and ER-stress related apoptosis in human UC (T24 and BFTC-905) cells. Additionally, co-treatment of PR-619 with cisplatin potentiated cisplatin-induced cytotoxicity in UC cells and was accompanied by the concurrent suppression of Bcl-2. We also proved that Bcl-2 overexpression is related to the chemo-resistant status in patients with metastatic UC by immunohistochemistry (IHC) staining. In a xenograft mice model, we confirmed that PR-619 enhanced the antitumor effect of cisplatin on cisplatin-naïve and cisplatin-resistant UCs. Our results demonstrated that PR-619 effectively enhanced the cisplatin-induced antitumor effect via concurrent suppression of the Bcl-2 level. These findings provide promising insight for developing a therapeutic strategy for UC treatment.

VEGF mediates fat embolism-induced acute lung injury via VEGF receptor 2 and the MAPK cascade.

Fat embolism (FE) is a lethal medical emergency often caused by fracture of long bones and amputation of limbs. Vascular endothelial growth factor (VEGF) promotes angiogenesis and increases vascular permeability. We tested the hypothesis that VEGF plays a critical role in FE-induced acute respiratory distress syndrome (ARDS) and acute lung injury (ALI). Fat tissues were collected from male Sprague-Dawley rats, and animal oil was extracted and mixed with water to form fatty micelles. The micelles were then injected into the tail vein to produce FE and ALI in rats. Lung weight gain was measured as the index of pulmonary edema. The expression of pulmonary VEGF was evaluated by real-time PCR and western blot analysis. Inducible nitric oxide synthase (iNOS) and phosphorylation of mitogen-activated protein kinase (MAPK) were determined by western blot analyses. Interleukin-1ß (IL-1ß) was quantified by ELISAs. Hematoxylin and eosin staining was used to evaluate the pathological damage of ALI. In this study, we found that animal oil-induced FE significantly increased pulmonary VEGF expression and MAPK phosphorylation. We also evaluated the inflammatory response after FE and found that iNOS and IL-1ß significantly increased after FE. Systemic administration of SU-1498, an antagonist of VEGF receptor 2 (VEGFR-2), significantly attenuated the FE-induced inflammatory response and histological damage. This study suggested that VEGF is involved in FE-induced ARDS via the VEGFR-2 and MAPK cascades, which induce IL-1ß release and iNOS upregulation. Blockade of could be used to treat FE-induced pulmonary damage.

Flavopereirine Suppresses the Growth of Colorectal Cancer Cells through P53 Signaling Dependence.

Colorectal cancer (CRC) is a significant cause of morbidity and mortality worldwide. The outcome of CRC patients remains poor. Thus, a new strategy for CRC treatment is urgently needed. Flavopereirine is a ß-carboline alkaloid extracted from Geissospermum vellosii, which can reduce the viability of various cancer cells through an unknown mode of action. The aim of the present study was to investigate the functional mechanism and therapeutic potential of flavopereirine on CRC cells in vitro and in vivo. Our data showed that flavopereirine significantly lowered cellular viability, caused intrinsic and extrinsic apoptosis, and induced G2/M-phase cell cycle arrest in CRC cells. Flavopereirine downregulated Janus kinases-signal transducers and activators of transcription (JAKs-STATs) and cellular myelocytomatosis (c-Myc) signaling in CRC cells. In contrast, the enforced expressions of constitutive active STAT3 and c-Myc could not restore flavopereirine-induced viability reduction. Moreover, flavopereirine enhanced P53 expression and phosphorylation in CRC cells. CRC cells with P53 knockout or loss-of-function mutation significantly diminished flavopereirine-mediated viability reduction, indicating that P53 activity plays a major role in flavopereirine-mediated CRC cell growth suppression. Flavopereirine also significantly repressed CRC cell xenograft growth in vivo by upregulating P53 and P21 and inducing apoptosis. In conclusion, flavopereirine-mediated growth suppression in CRC cells depended on the P53-P21, but not the JAKs-STATs-c-Myc signaling pathway. The present study suggests that flavopereirine may be efficacious in the clinical treatment of CRC harboring functional P53 signaling.

Trifluoperazine, an Antipsychotic Drug, Effectively Reduces Drug Resistance in Cisplatin-Resistant Urothelial Carcinoma Cells via Suppressing Bcl-xL: An In Vitro and In Vivo Study.

Cisplatin-based chemotherapy is the primary treatment for metastatic bladder urothelial carcinoma (UC). Most patients inevitably encounter drug resistance and resultant disease relapse. Reduced apoptosis plays a critical role in chemoresistance. Trifluoperazine (TFP), an antipsychotic agent, has demonstrated antitumor effects on various cancers. This study investigated the efficacy of TFP in inhibiting cisplatin-resistant bladder UC and explored the underlying mechanism. Our results revealed that cisplatin-resistant UC cells (T24/R) upregulated the antiapoptotic factor, B-cell lymphoma-extra large (Bcl-xL). Knockdown of Bcl-xL by siRNA resensitized cisplatin-resistant cells to the cisplatin cytotoxic effect. TFP (10-45 µM) alone elicited dose-dependent cytotoxicity, apoptosis, and G0/G1 arrest on T24/R cells. Co-treatment of TFP potentiated cisplatin-induced cytotoxicity in T24/R cells. The phenomenon that TFP alleviated cisplatin resistance to T24/R was accompanied with concurrent suppression of Bcl-xL. In vivo models confirmed that TFP alone effectively suppressed the T24/R xenograft in nude mice. TFP co-treatment enhanced the antitumor effect of cisplatin on the T24/R xenograft. Our results demonstrated that TFP effectively inhibited cisplatin-resistant UCs and circumvented cisplatin resistance with concurrent Bcl-xL downregulation. These findings provide a promising insight to develop a therapeutic strategy for chemoresistant UCs.

Cyclooxygenase-2 Activity Regulates Recruitment of VEGF-Secreting Ly6Chigh Monocytes in Ventilator-Induced Lung Injury.

Mechanical ventilation is usually required for saving lives in critically ill patients; however, it can cause ventilator-induced lung injury (VILI). As VEGF-secreting Ly6Chigh monocytes are involved in VILI pathogenesis, we investigated whether cyclooxygenase-2 (COX-2) activity regulates the recruitment of VEGF-secreting Ly6Chigh monocytes during VILI. The clinically relevant two-hit mouse model of VILI, which involves the intravenous injection of lipopolysaccharide prior to high tidal volume (HTV)-mechanical ventilation, was used in this study. To investigate the role of COX-2 in the recruitment of VEGF-secreting Ly6Chigh monocytes during VILI, celecoxib, which is a clinical COX-2 inhibitor, was administered 1 h prior to HTV-mechanical ventilation. Pulmonary vascular permeability and leakage, inflammatory leukocyte infiltration, and lung oxygenation levels were measured to assess the severity of VILI. HTV-mechanical ventilation significantly increased the recruitment of COX-2-expressing Ly6Chigh, but not Ly6Clow, monocytes. Celecoxib significantly diminished the recruitment of Ly6Chigh monocytes, attenuated the levels of VEGF and total protein in bronchoalveolar lavage fluid, and restored pulmonary oxygenation during VILI. Our findings demonstrate that COX-2 activity is important in the recruitment of VEGF-secreting Ly6Chigh monocytes, which are involved in VILI pathogenesis, and indicate that the suppression of COX-2 activity might be a useful strategy in mitigating VILI.

Histone Deacetylase Inhibitor, Trichostatin A, Synergistically Enhances Paclitaxel-Induced Cytotoxicity in Urothelial Carcinoma Cells by Suppressing the ERK Pathway.

Trichostatin A (TSA), an antifungal antibiotic derived from Streptomyces, inhibits mammalian histone deacetylases, and especially, selectively inhibits class I and II histone deacetylase (HDAC) families of enzymes. TSA reportedly elicits an antiproliferative response in multifarious tumors. This study investigated the antitumor effects of TSA alone and in combination with paclitaxel when applied to two high-grade urothelial carcinoma (UC) cell lines (BFTC-905 and BFTC-909). Fluorescence-activated cell sorting, flow cytometry, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium assay were used to assess TSA's cytotoxicity and effects on apoptosis induction. TSA induced synergistic cytotoxicity, when combined with paclitaxel (combination index < 1), resulted in concomitant suppression of paclitaxel-induced activation of phospho-extracellular signal-regulated kinase (ERK) 1/2. A xenograft nude mouse model confirmed that TSA enhances the antitumor effects of paclitaxel. These findings demonstrate that the administration of TSA in combination with paclitaxel elicits a synergistic cytotoxic response. The results of this study indicate that the chemoresistance of UC could be circumvented by combining HDAC inhibitors to target the ERK pathway.

Correction to: Trichostatin A, a histone deacetylase inhibitor, induces synergistic cytotoxicity with chemotherapy via suppression of Raf/MEK/ERK pathway in urothelial carcinoma.

In Fig. 1b, upper part, the cell viability counts after treatment with cisplatin and TSA in T24 cells was by mistake a duplication of the image for NTUB1 on the left. In the corrected version of Fig. 1, the image was replaced appropriately.