Feasibility and Tolerability of Anlotinib Plus PD-1 Blockades for Patients with Treatment-Refractory Metastatic Colorectal Cancer: A Retrospective Exploratory Study.

Objective: Therapeutic regimens are relatively scarce among patients with treatment-refractory metastatic colorectal cancer (CRC). This study aimed to determine the feasibility and tolerability of anlotinib plus PD-1 blockades in patients with treatment-refractory metastatic CRC retrospectively. Methods: A total of 68 patients with previously treated metastatic CRC who received anlotinib plus PD-1 blockades in clinical practice were included in this study retrospectively. Demographic and clinical characteristics of the patients, therapeutic outcomes and safety profile during administration were collected and briefly analyzed. All subjects were followed up regularly. Therapeutic outcomes, including drug response and prognosis, were presented, and a safety profile was depicted to illustrate the adverse reactions. Results: A total of 68 patients with treatment-refractory metastatic CRC who received anlotinib plus PD-1 blockades in clinical practice were included in the final analysis. Best therapeutic response during treatment indicated that partial response was observed in 11 patients, stable disease was noted in 41 patients, and progressive disease was found in 16 patients, producing an objective response rate of 16.2% (95% CI: 8.4%-27.1%) and a disease control rate of 76.5% (95% CI: 64.6%-85.9%). Prognostic analysis suggested that the median progression-free survival (PFS) of the 68 patients was 5.3 months (95% CI: 3.01-7.59), and the median overall survival (OS) was 12.5 months (95% CI: 9.40-15.60). Of the 11 patients who responded, the median duration of response was 6.7 months (95% CI: 2.89-10.53). Safety profile during treatment showed that patients experienced adverse reactions regardless of grade, and grade ≥3 adverse reactions were found in 61 patients (89.7%) and 41 patients (60.3%), respectively. Common adverse reactions were hypertension, myelosuppression (including leukopenia, neutropenia, thrombocytopenia, and anemia), fatigue, and hand-foot syndrome. Conclusion: Anlotinib plus PD-1 blockades demonstrated encouraging efficacy and acceptable safety profile in patients with treatment-refractory metastatic CRC preliminarily in clinical practice. This conclusion should be confirmed in prospective clinical trials.

The Role of Autophagy in Human Uveal Melanoma and the Development of Potential Disease Biomarkers and Novel Therapeutic Paradigms.

Autophagy is a form of programmed cell degradation that enables the maintenance of homeostasis in response to extracellular stress stimuli. Autophagy is primarily activated by starvation and mediates the degradation, removal, or recycling of cell cytoplasm, organelles, and intracellular components in eukaryotic cells. Autophagy is also involved in the pathogenesis of human diseases, including several cancers. Human uveal melanoma (UM) is the primary intraocular malignancy in adults and has an extremely poor prognosis; at present there are no effective therapies. Several studies have suggested that autophagy is important in UM. By understanding the mechanisms of activation of autophagy in UM it may be possible to develop biomarkers to provide more definitive disease prognoses and to identify potential drug targets for the development of new therapeutic strategies. This article reviews the current information regarding autophagy in UM that could facilitate biomarker and drug development.

Structure-Interaction Relationship of Polymyxins with Lung Surfactant.

Multidrug-resistant Gram-negative bacteria present an urgent and formidable threat to the global public health. Polymyxins have emerged as a last-resort therapy against these 'superbugs'; however, their efficacy against pulmonary infection is poor. In this study, we integrated chemical biology and molecular dynamics simulations to examine how the alveolar lung surfactant significantly reduces polymyxin antibacterial activity. We discovered that lung surfactant is a phospholipid-based permeability barrier against polymyxins, compromising their efficacy against target bacteria. Next, we unraveled the structure-interaction relationship between polymyxins and lung surfactant, elucidating the thermodynamics that govern the penetration of polymyxins through this critical surfactant layer. Moreover, we developed a novel analog, FADDI-235, which exhibited potent activity against Gram-negative bacteria, both in the presence and absence of lung surfactant. These findings shed new light on the sequestration mechanism of lung surfactant on polymyxins and importantly pave the way for the rational design of new-generation lipopeptide antibiotics to effectively treat Gram-negative bacterial pneumonia.

Lapatinib dysregulates HER2 signaling and impairs the viability of human uveal melanoma cells.

Uveal melanoma (UM) is the principal type of intraocular malignancy in adults. Up to 50% of UM patients develop metastatic disease with very poor survival. There are few drugs available to treat the primary or metastatic UM. This study was undertaken to evaluate the anti-cancer effect of lapatinib and corroborate the potential of HER2 inhibition in the treatment of UM. The anti-UM activity of lapatinib was assessed using cell viability, cell death and cell cycle analysis, and its anti-metastatic actions were evaluated using would healing, invasion and colony formation assays. Immunoblotting was used to substantiate the actions of lapatinib on apoptotic and HER2 signaling. The anti-UM activity of lapatinib was further evaluated in a UM xenograft mouse model. Lapatinib decreased the viability of four UM cell lines (IC50: 3.67-6.53 µM). The antiproliferative activity of lapatinib was corroborated in three primary cell lines isolated from UM patient tumors. In UM cell lines, lapatinib promoted apoptosis and cell cycle arrest, and strongly inhibited cell migration, invasion and reproductive cell growth. Lapatinib dysregulated HER2-AKT/ERK/PI3K signalling leading to the altered expression of apoptotic factors and cell cycle mediators in UM cell lines. Importantly, lapatinib suppressed tumourigenesis in mice carrying UM cell xenografts. Together the present findings are consistent with the assertion that HER2 is a viable therapeutic target in UM. Lapatinib is active in primary and metastatic UM as a clinically approved HER2 inhibitor. The activity of lapatinib in UM patients could be evaluated in future clinical trials.

Molecular Insights to the Structure-Interaction Relationships of Human Proton-Coupled Oligopeptide Transporters (PepTs).

Human proton-coupled oligopeptide transporters (PepTs) are important membrane influx transporters that facilitate the cellular uptake of many drugs including ACE inhibitors and antibiotics. PepTs mediate the absorption of di- and tri-peptides from dietary proteins or gastrointestinal secretions, facilitate the reabsorption of peptide-bound amino acids in the kidney, and regulate neuropeptide homeostasis in extracellular fluids. PepT1 and PepT2 have been the most intensively investigated of all PepT isoforms. Modulating the interactions of PepTs and their drug substrates could influence treatment outcomes and adverse effects with certain therapies. In recent studies, topology models and protein structures of PepTs have been developed. The aim of this review was to summarise the current knowledge regarding structure-interaction relationships (SIRs) of PepTs and their substrates as well as the potential applications of this information in therapeutic optimisation and drug development. Such information may provide insights into the efficacy of PepT drug substrates in patients, mechanisms of drug-drug/food interactions and the potential role of PepTs targeting in drug design and development strategies.

Single-cell RNA sequencing reveals the dynamics of hepatic non-parenchymal cells in autoprotection against acetaminophen-induced hepatotoxicity.

Gaining a better understanding of autoprotection against drug-induced liver injury (DILI) may provide new strategies for its prevention and therapy. However, little is known about the underlying mechanisms of this phenomenon. We used single-cell RNA sequencing to characterize the dynamics and functions of hepatic non-parenchymal cells (NPCs) in autoprotection against DILI, using acetaminophen (APAP) as a model drug. Autoprotection was modeled through pretreatment with a mildly hepatotoxic dose of APAP in mice, followed by a higher dose in a secondary challenge. NPC subsets and dynamic changes were identified in the APAP (hepatotoxicity-sensitive) and APAP-resistant (hepatotoxicity-resistant) groups. A chemokine (C-C motif) ligand 2+ endothelial cell subset almost disappeared in the APAP-resistant group, and an R-spondin 3+ endothelial cell subset promoted hepatocyte proliferation and played an important role in APAP autoprotection. Moreover, the dendritic cell subset DC-3 may protect the liver from APAP hepatotoxicity by inducing low reactivity and suppressing the autoimmune response and occurrence of inflammation. DC-3 cells also promoted angiogenesis through crosstalk with endothelial cells via vascular endothelial growth factor-associated ligand-receptor pairs and facilitated liver tissue repair in the APAP-resistant group. In addition, the natural killer cell subsets NK-3 and NK-4 and the Sca-1-CD62L+ natural killer T cell subset may promote autoprotection through interferon-γ-dependent pathways. Furthermore, macrophage and neutrophil subpopulations with anti-inflammatory phenotypes promoted tolerance to APAP hepatotoxicity. Overall, this study reveals the dynamics of NPCs in the resistance to APAP hepatotoxicity and provides novel insights into the mechanism of autoprotection against DILI at a high resolution.

Ginkgo biloba extract ameliorates hyperglycaemia-induced enteric glial cell injury via regulation of the TLR2-related pathway.

BACKGROUND: Diabetic gastrointestinal dysfunction (DGD) is a common complication in diabetic patients, and enteric glial cells (EGCs) found in the gastrointestinal tract have been shown to play an essential role in gastrointestinal dysfunction. Thus, targeting EGCs may be helpful for the control of DGD. This study aimed to evaluate the protective effect of Ginkgo biloba extract (GBE) from G. biloba dropping pills against hyperglycaemic stress-induced EGCs injury and its underlying mechanism. METHODS: In vitro, the protective effect of GBE on CRL-2690 cells was evaluated by MTT assay and TUNEL assay. The expression of related markers was evaluated by RNA sequencing and validated by using western blotting. In vivo, STZ-induced C57BL/6J WT mice were used as models to evaluate the effects of GBE on blood glucose, body weight, and EGCs' activity and relevant signalling pathways were validated by immunofluorescence. RESULTS: The results showed that GBE (25 µg/ml) treatment significantly attenuated hyperglycaemic stress-induced cytotoxicity and cell apoptosis in CRL-2690 cells, which was verified in an STZ-induced (100 mg/kg, 3 days) diabetic mouse model with continuous GBE administration (25/100 mg/kg/day, 6/12 weeks). Further mechanistic study based on transcriptomic data revealed that GBE exerted its beneficial effect by regulating immune-related pathways, and TLR2/BTK/NF-κB/IL-1α/IL-10 comprised the main targets of this drug. CONCLUSIONS: This study demonstrates the protective effect of GBE against hyperglycaemic stress-induced EGCs injury using both in vitro and in vivo models and further reveals that the effect was achieved by targeting TLR2 and its downstream molecules BTK/NF-κB/IL-1α/IL-10. This study may be helpful for expanding the clinical application of GBE in treating DGD.

Depression status and functional outcome of patients with ischemic stroke and the impact on caregivers living in Chengdu: a cross-sectional study.

Objectives: To investigate the associations between risk factors and depression symptoms in ischemic stroke (IS) survivors and the effect of IS survivors' depression status and functional outcomes on caregiver burden in Chengdu, China. Methods: In this cross-sectional study, we recruited a convenience sample of patients with IS and paired caregivers living in Chengdu from February 2022 to May 2022. Depression symptoms were assessed using the 17-item Chinese Hamilton Depression Rating Scale, the social support of patients was assessed using the perceived social support scale (PSSS), caregiver burden was assessed using the Zarit burden interview (ZBI). Multivariable logistic regression analysis was used to analyze the data between risk factors and depression symptoms, and multiple linear regression models were constructed to examine the depression symptoms and functional outcomes of stroke survivors, and caregiver burden. Results: In total, 966 IS survivors and paired caregivers were included in this study. Among IS survivors, 35.51% (343/966) experienced depression. Age [adjusted odds ratio (aOR), 1.02; 95% confidence interval (CI), 1.00-1.04; p = 0.036], the National Institutes of Health Stroke Scale (NIHSS) score (aOR, 1.57; 95% CI, 1.47-1.68; p < 0.001), and PSSS score (aOR, 0.86; 95% CI, 0.84-0.89; p < 0.001) were associated with an increased risk of depression. The NIHSS score (b = 2.57, p < 0.001), patients' depression status (b = 2.54, p < 0.001), duration of care (b = 0.359, p = 0.006), and social support of caregivers (b = -0.894, p = 0.038) were significantly associated with the ZBI score. Conclusion: The PSSS score was a major risk factor for the development of depression in IS survivors, and patients' depression status and severe functional deficits had a negative impact on the ZBI score of the main caregivers. Social support can reduce the ZBI score.

Recent advances and prospects for lipid-based nanoparticles as drug carriers in the treatment of human retinal diseases.

The delivery of cures for retinal diseases remains problematic. There are four main challenges: passing through multiple barriers of the eye, the delivery to particular retinal cell types, the capability to carry different forms of therapeutic cargo and long-term therapeutic efficacy. Lipid-based nanoparticles (LBNPs) are potent to overcome these challenges due to their unique merits: amphiphilic nanoarchitectures to pass biological barriers, vary modifications with specific affinity to target cell types, flexible capacity for large and mixed types of cargos and slow-release formulations for long-term treatment. We have reviewed the latest research on the applications of LBNPs for treating retinal diseases and categorized them by different payloads. Furthermore, we identified technical barriers and discussed possible future development for LBNPs to expand the therapeutic potential in treating retinal diseases.

The Role of Nrf2/sMAF Signalling in Retina Ageing and Retinal Diseases.

Age-related diseases, such as Parkinson's disease, Alzheimer's disease, cardiovascular diseases, cancers, and age-related macular disease, have become increasingly prominent as the population ages. Oxygen is essential for living organisms, but it may also cause disease when it is transformed into reactive oxygen species via biological processes in cells. Most of the production of ROS occurs in mitochondrial complexes I and III. The accumulation of ROS in cells causes oxidative stress, which plays a crucial role in human ageing and many diseases. Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a key antioxidant transcription factor that plays a central role in many diseases and ageing in general. It regulates many downstream antioxidative enzymes when cells are exposed to oxidative stress. A basic-region leucine zipper (bZIP) transcription factor, MAF, specifically the small MAF subfamily (sMAFs), forms heterodimers with Nrf2, which bind with Maf-recognition elements (MAREs) in response to oxidative stress. The role of this complex in the human retina remains unclear. This review summarises the current knowledge about Nrf2 and its downstream signalling, especially its cofactor-MAF, in ageing and diseases, with a focus on the retina. Since Nrf2 is the master regulator of redox homeostasis in cells, we hypothesise that targeting Nrf2 is a promising therapeutic approach for many age-related diseases.

An update on inflammation in uveal melanoma.

Uveal melanoma (UM) is the primary ocular cancer with upto 50% of patients dying from metastasis. Although rare, it is deadly as patients with metastatic UM seldom survive beyond 18 months after diagnosis. Chemotherapeutics have no proven efficacy, including immunotherapies that have been tried as current treatment options but produce marginal improvement in overall survival for UM patients. While therapeutics are low in efficacy, there is an urgent need to explore novel targets in the treatment of UM. This review provides an update on the contribution of inflammation to UM with a focus on exploring potential therapeutic targets related to the inflammatory tumour microenvironment. As a tumour promoting event, inflammation is one of the hallmarks of cancers. The presence of the inflammatory phenotype characterised by the abundance of immune mediators and proinflammatory cytokines surrounding UM tumours, is a potential area to explore novel therapeutic targets. Despite decades of investigation regarding the role UM tumour microenvironment has played, that of inflammation in UM progression remains poorly understood. With advancement of technologies, an understanding of the prognosis of UM has been accelerated. Excitingly, novel therapeutic targets related to the inflammatory tumour microenvironment have been identified and relevant studies are underway in their preliminary phases, illustrating optimistic results.

Ginkgo biloba extracts (GBE) protect human RPE cells from t-BHP-induced oxidative stress and necrosis by activating the Nrf2-mediated antioxidant defence.

OBJECTIVES: Age-related macular degeneration (AMD) is a prevalent ocular disease. Dry AMD accounts for most cases of blindness associated with AMD but there are no treatments. Oxidative stress-induced damage to retinal pigment epithelial (RPE) cells is a major contributor to the pathogenesis of dry AMD. This study investigated the protective actions of Ginkgo biloba extracts (GBE) in human RPE cells subjected to tert-butyl hydroperoxide (t-BHP)-mediated oxidative stress. METHODS: The human ARPE-19 cells were pre-treated with or without GBE before the exposure to t-BHP. Cell viability, cell death profile and lipid peroxidation were assessed. The findings were verified using human primary RPE cultures. KEY FINDINGS: GBE pre-treatment prevented the increase in lipid peroxidation and necrosis/ferroptosis, and the concurrent viability decrease in RPE cells exposed to t-BHP. It enabled the pronounced activation of Nrf2 and its downstream genes. We found that ERK1/2 phosphorylation was increased to a similar extent by t-BHP and GBE. CONCLUSION: This study revealed that GBE pre-treatment attenuates pro-oxidant stress and protects human RPE cells from oxidative injury by modulating ERK1/2-Nrf2 axis. These findings suggest that GBE has the potential to be developed as a agent that may be valuable in decreasing AMD progression.

Ginkgo biloba extracts protect human retinal Müller glial cells from t-BHP induced oxidative damage by activating the AMPK-Nrf2-NQO-1 axis.

OBJECTIVES: Retinal Müller glial cell loss is almost involved in all retinal diseases, especially diabetic retinopathy (DR). Oxidative stress significantly contributes to the development of Müller glial cell loss. Ginkgo biloba extracts (GBE) have been reported to possess antioxidant property, beneficial in treating human retinal diseases. However, little is known about its role in Müller glial cells. This study investigated the protective effect of GBE (prepared from ginkgo biloba dropping pills) in human Müller glial cells against tert-butyl hydroperoxide (t-BHP)-induced oxidative stress and its underlying molecular mechanism. METHODS: MIO-M1 cells were pretreated with or without GBE prior to the exposure to t-BHP-induced oxidative stress. Cell viability, cell death profile and lipid peroxidation were subsequently assessed. Protein expression of the key anti-oxidative signalling factors were investigated. KEY FINDINGS: We showed that GBE can effectively protect human MIO-M1 cells from t-BHP-induced oxidative injury by improving cell viability, reducing intracellular ROS accumulation and suppressing lipid peroxidation, which effect is likely mediated through activating AMPK-Nrf2-NQO-1 antioxidant respondent axis. CONCLUSIONS: Our study is the first to reveal the great potentials of GBE in protecting human retinal Müller glial cell loss against oxidative stress. GBE might be used to prevent human retinal diseases particularly DR.

Inhibiting the activation of MAPK (ERK1/2) in stressed Müller cells prevents photoreceptor degeneration.

Rationale: Müller cells play an essential role in maintaining the health of retinal photoreceptors. Dysfunction of stressed Müller cells often results in photoreceptor degeneration. However, how these cells communicate under stress and the signalling pathways involved remain unclear. In this study, we inhibited the MAPK (ERK1/2) signalling, mainly activated in Müller cells, evaluated the protective effects on the photoreceptors and further explored the signalling communication between stressed Müller cells and degenerating photoreceptors. Methods: We evaluated the changes of MAPK (ERK1/2) signalling and its downstream targets in human retinal explants treated with PD98059, a specific phosphorylated ERK1/2 inhibitor, by western blot and immunostaining. We further assessed photoreceptor degeneration by TUNEL staining and outer nuclear layer thickness. We also injected PD98059 into the eyes of mice exposed to photo-oxidative stress. We evaluated the protective effects on photoreceptor degeneration by optical coherence tomography (OCT) and electroretinography (ERG). The crosstalk between Müller cells and photoreceptors was further dissected based on the changes of transcription factors by RNA sequencing and protein profiles of multiple signalling pathways. Results: We found that MAPK (ERK1/2) signalling was mainly activated in Müller cells under stress, both ex vivo and in vivo. PD98059 inhibited the phosphorylation of ERK1/2, reduced expression of the gliotic marker glial fibrillary acidic protein (GFAP) in Müller cells and increased levels of the neuroprotective factor, interphotoreceptor retinoid-binding protein (IRBP) in photoreceptors. Inhibition of pERK1/2 also reduced retinal photo-oxidative damage in mice retinas assessed by OCT and ERG. We also identified that the JAK/STAT3 signalling pathway might mediate signalling transduction from Müller cells to photoreceptors. Conclusion: MAPK (ERK1/2) deactivation through chemical inhibition, mainly in stressed Müller cells, can alleviate gliosis in Müller cells and restore the expression of IRBP in photoreceptors, which appears to prevent retinal degeneration. Our findings suggested a new way to prevent photoreceptor degeneration by manipulating the stress response in Müller cells.

The potential of Ginkgo biloba in the treatment of human diseases and the relationship to Nrf2-mediated antioxidant protection.

OBJECTIVES: This review summarises the current findings regarding the therapeutic effects of GBE and its active ingredients in relation to the Nrf2 antioxidant cascade, to provide scientific insights into the clinical applications of GBE in treating oxidative stress-induced diseases. KEY FINDINGS: We found that GBE or its active ingredients activate several signalling mechanisms in cells, including the Nrf2 pathway, which is the master controller of the antioxidant defence that detoxifies reactive oxygen species (ROS). ROS-mediated cell and tissue damage contributes to ageing and pathological conditions that underlie several important human diseases, such as diabetic nephropathy (DN), ischemic stroke and age-related macular degeneration (AMD). SUMMARY: GBE or its component antioxidants could be applied for the treatment and/or prevention of DN, ischemic stroke and AMD due to their capacity to activate Nrf2 signalling. These strategies may also be applicable to the treatment of other similar conditions that are induced by oxidative stress. Thus, the therapeutic applications of GBE could be expanded.

The ixabepilone and vandetanib combination shows synergistic activity in docetaxel-resistant MDA-MB-231 breast cancer cells.

BACKGROUND: The lack of drug targets is an obstacle to the treatment of patients with triple-negative breast cancer (TNBC). At present, non-specific cytotoxic drugs are first-line agents, but the development of resistance is a major problem with these agents. The epidermal growth factor receptor (EGFR) is a potential target in some TNBCs, because its tyrosine kinase activity drives tumorigenesis. Thus, small molecule inhibitors of the EGFR in combination with cytotoxic agents could be important for the treatment of TNBCs. METHODS: The present study evaluated the efficacies of clinically approved EGFR inhibitors in combination with the cytotoxic agent ixabepilone in parental and docetaxel-resistant MDA-MB-231 cells (231C and TXT cells, respectively). Cell viability was assessed using MTT reduction assays, cell death pathways were evaluated using annexin V/7-aminoactinomycin D staining and flow cytometry and Western immunoblotting was used to assess the expression of pro- and anti-apoptotic proteins in cells. RESULTS: Ixabepilone and the EGFR inhibitors gefitinib and vandetanib inhibited 231C and TXT cell proliferation, but the alternate EGFR inhibitors erlotinib and lapatinib were poorly active. Using combination analysis, ixabepilone/vandetanib was synergistic in both cell types, whereas the ixabepilone/gefitinib combination exhibited antagonism. By flow cytometry, ixabepilone/vandetanib enhanced 231C and TXT cell death over that produced by the single agents and also enhanced caspase-3 cleavage and the pro/anti-apoptotic Bcl-2 protein ratios over ixabepilone alone. CONCLUSIONS: These findings suggest that the ixabepilone/vandetanib combination may have promise for the treatment of patients with drug-resistant TNBC.

Procyanidin B2 suppresses hyperglycemia-induced renal mesangial cell dysfunction by modulating CAV-1-dependent signaling.

The dysfunction of renal mesangial cells (MCs) is a hallmark of diabetic kidney disease (DKD), which triggers glomerulosclerosis leading to end-stage renal disease. Procyanidin B2 (PB2), the main component of proanthocyanidin, is well known for its antioxidant and anti-inflammatory effects; however, it remains unclear as to whether it has protective effects on DKD. The present study investigated the protective effect of PB2 against hyperglycemia-induced renal MC dysfunction in mouse SV40-Mes13 (Mes13) cells. The Mes13 cells were treated with or without PB2 under HG conditions. Cell proliferation was assessed using an MTT assay and oxidative stress was assessed by examining intracellular ROS generation and H2O2 production. The changes in extracellular matrix accumulation- and cellular inflammation-related proteins were measured by western blot analysis, ELISA and immunofluorescence analysis. The results showed that PB2 treatment markedly attenuated hyperglycemia-induced cell proliferation, oxidative stress, extracellular matrix accumulation and cellular inflammation in Mes13 cells, which was accompanied by an inactivation of redoxosomes, TGF-ß1/SMAD and IL-1ß/TNF-α/NF-κB signaling pathways. The present study also demonstrated that hyperglycemia upregulated and activated caveolin-1 (CAV-1), whereas PB2 treatment potently reversed this effect. In accordance, CAV-1 overexpression abolished the protective effects of PB2 against hyperglycemia in Mes13 cells, indicating that the cytoprotective effect of PB2 was CAV-1-dependent. These findings form the basis of the potential clinical applications of PB2 in the treatment of DKD.

Ginkgo biloba Extract Attenuates Light-Induced Photoreceptor Degeneration by Modulating CAV-1-Redoxosome Signaling.

The clinical potential of Ginkgo biloba extract (GBE) in the prevention and/or treatment of retinal degenerative diseases has been widely explored; however, the underlying molecular mechanism is poorly understood. Photoreceptor degeneration is the hallmark of retinal degenerative diseases and leads to vision impairment or loss. In this study, the effect of GBE against white light (WL) illumination-induced photoreceptor degeneration was investigated, as well as its underlying mechanism. To evaluate the in vitro activity of GBE, analysis of cell viability, cell apoptosis, oxidative stress, NOX (NADH oxidase) activity and mitochondrial membrane potential (MMP), as well as Western blotting and transcriptome sequencing and analysis, were conducted. To evaluate the in vivo activity of GBE, HE staining, electroretinography (ERG), Terminal-deoxynucleoitidyl transferase (TdT)-mediated nick end labeling (TUNEL) assay and immunofluorescence analysis were conducted. Our study showed that GBE treatment significantly attenuated WL illumination-induced oxidative damage in photoreceptor 661W cells-a finding that was also verified in C57BL/6J mice. Further molecular study revealed that WL illumination downregulated caveolin-1 (CAV-1) expression, interrupted CAV-1-NOX2 interaction, re-located NOX2 from the cell membrane to the cytoplasm and induced the formation of redoxosomes, which led to cell death. However, these cytotoxic events were significantly alleviated by GBE treatment. Interestingly, CAV-1 overexpression showed a consistent protective effect with GBE, while CAV-1 silencing impacted the protective effect of GBE against WL illumination-induced oxidative damage in in vitro and in vivo models. Thus, GBE was identified to prevent photoreceptor cell death due to CAV-1-dependent redoxosome activation, oxidative stress and mitochondrial dysfunction resulting from WL illumination. Overall, our study reveals the protective effect of GBE on photoreceptors against WL illumination-induced oxidative damage in in vitro and in vivo models, which effect is mediated through the modulation of CAV-1-redoxosome signaling. Our findings contribute to better understanding the therapeutic effect of GBE in preventing photoreceptor degeneration in retinal degenerative diseases, and GBE may become a novel therapeutic agent that is effective in reducing the morbidity of these diseases.

The multi-kinase inhibitor afatinib serves as a novel candidate for the treatment of human uveal melanoma.

PURPOSE: Uveal melanoma (UM) is the most common intraocular malignancy in adults with a poor prognosis and a high recurrence rate. Currently there is no effective treatment for UM. Multi-kinase inhibitors targeting dysregulated pro-tumorigenic signalling pathways have revolutionised anti-cancer treatment but, as yet, their efficacy in UM has not been established. Here, we identified the multi-kinase inhibitor afatinib as a highly effective agent that exerts anti-UM effects in in vitro, ex vivo and in vivo models. METHODS: We assessed the anti-cancer effects of afatinib using cell viability, cell death and cell cycle assays in in vitro and ex vivo UM models. The signaling pathways involved in the anti-UM effects of afatinib were evaluated by Western blotting. The in vivo activity of afatinib was evaluated in UM xenograft models using tumour mass measurement, PET scan, immunohistochemical staining and TUNEL assays. RESULTS: We found that afatinib reduced cell viability and activated apoptosis and cell cycle arrest in multiple established UM cell lines and in patient tumour-derived primary cell lines. Afatinib impaired cell migration and enhanced reproductive death in these UM cell models. Afatinib-induced cell death was accompanied by activation of STAT1 expression and downregulation of Bcl-xL and cyclin D1 expression, which control cell survival and cell cycle progression. Afatinib attenuated HER2-AKT/ERK/PI3K signalling in UM cell lines. Consistent with these observations, we found that afatinib suppressed tumour growth in UM xenografted mice. CONCLUSION: Our data indicate that afatinib activates UM cell death and targets the HER2-mediated cascade, which modulates STAT1-Bcl-xL/cyclin D1 signalling. Thus, targeting HER2 with agents like afatinib may be a novel therapeutic strategy to treat UM and to prevent metastasis.

Preclinical Evaluation of Ixabepilone in Combination with VEGF Receptor and PARP Inhibitors in Taxane-Sensitive and Taxane-Resistant MDA-MB-231 Breast Cancer Cells.

Long-term use of cytotoxic agents promotes drug-resistance in triple-negative breast cancer (TNBC). The identification of new drug combinations with efficacy against drug-resistant TNBC cells in vitro is valuable in developing new clinical strategies to produce further cancer remissions. We undertook combination analysis of the cytotoxic agent ixabepilone with small molecule inhibitors of vascular endothelial growth factor receptor (VEGFR) and poly (ADP-ribose) polymerase (PARP) in taxane-sensitive (231C) and taxane-resistant (TXT) MDA-MB-231-derived cells. As single agents, the VEGFR inhibitors cediranib and bosutinib decreased both 231C and TXT cell viability, but four other VEGFR inhibitors and two PARP inhibitors were less effective. Combinations of ixabepilone with either cediranib or bosutinib synergistically decreased 231C cell viability. However, only the ixabepilone/cediranib combination was synergistic in TXT cells, with predicted 15.3-fold and 1.65-fold clinical dose reductions for ixabepilone and cediranib, respectively. Flow cytometry and immunoblotting were used to further evaluate the loss of cell viability. Thus, TXT cell killing by ixabepilone/cediranib was enhanced over ixabepilone alone, and expression of proapoptotic cleaved caspase-3 and the Bak/Bcl-2 protein ratio were increased. These findings suggest that the synergistic activity of the ixabepilone/cediranib combination in taxane-sensitive and taxane-resistant cells may warrant clinical evaluation in TNBC patients.