DOCK2 Promotes Atherosclerosis by Mediating the Endothelial Cell Inflammatory Response.

The pathology of atherosclerosis, a leading cause of mortality in patients with cardiovascular disease, involves inflammatory phenotypic changes in vascular endothelial cells. This study explored the role of the dedicator of cytokinesis (DOCK)-2 protein in atherosclerosis. Mice with deficiencies in low-density lipoprotein receptor and Dock2 (Ldlr-/-Dock2-/-) and controls (Ldlr-/-) were fed a high-fat diet (HFD) to induce atherosclerosis. In controls, Dock2 was increased in atherosclerotic lesions, with increased intercellular adhesion molecule (Icam)-1 and vascular cell adhesion molecule (Vcam)-1, after HFD for 4 weeks. Ldlr-/-Dock2-/- mice exhibited significantly decreased oil red O staining in both aortic roots and aortas compared to that in controls after HFD for 12 weeks. In control mice and in humans, Dock2 was highly expressed in the ECs of atherosclerotic lesions. Dock2 deficiency was associated with attenuation of Icam-1, Vcam-1, and monocyte chemoattractant protein (Mcp)-1 in the aortic roots of mice fed HFD. Findings in human vascular ECs in vitro suggested that DOCK2 was required in TNF-α-mediated expression of ICAM-1/VCAM-1/MCP-1. DOCK2 knockdown was associated with attenuated NF-κB phosphorylation with TNF-α, partially accounting for DOCK2-mediated vascular inflammation. With DOCK2 knockdown in human vascular ECs, TNF-α-mediated VCAM-1 promoter activity was inhibited. The findings from this study suggest the novel concept that DOCK2 promotes the pathogenesis of atherosclerosis by modulating inflammation in vascular ECs.

MARCH8 downregulation modulates profibrotic responses including myofibroblast differentiation.

Interstitial lung diseases can result in poor patient outcomes, especially in idiopathic pulmonary fibrosis (IPF), a severe interstitial lung disease with unknown causes. The lack of treatment options requires further understanding of the pathological process/mediators. Membrane-associated RING-CH 8 (MARCH8) has been implicated in immune function regulation and inflammation, however, its role in the development of pulmonary fibrosis and particularly the fibroblast to myofibroblast transition (FMT) remains a gap in existing knowledge. In this study, we demonstrated decreased MARCH8 expression in patients with IPF compared with non-PF controls and in bleomycin-induced PF. TGF-ß dose- and time-dependently decreased MARCH8 expression in normal and IPF human lung fibroblast (HLFs), along with induction of FMT markers α-SMA, collagen type I (Col-1), and fibronectin (FN). Interestingly, overexpression of MARCH8 significantly suppressed TGF-ß-induced expression of α-SMA, Col-1, and FN. By contrast, the knockdown of MARCH8 using siRNA upregulated basal expression of α-SMA/Col-1/FN. Moreover, MARCH8 knockdown enhanced TGF-ß-induced FMT marker expression. These data clearly show that MARCH8 is a critical "brake" for FMT and potentially affects PF. We further found that TGF-ß suppressed MARCH8 mRNA expression and the proteasome inhibitor MG132 failed to block MARCH8 decrease induced by TGF-ß. Conversely, TGF-ß decreases mRNA levels of MARCH8 in a dose- and time-dependent manner, suggesting the transcriptional regulation of MARCH8 by TGF-ß. Mechanistically, MARCH8 overexpression suppressed TGF-ß-induced Smad2/3 phosphorylation, which may account for the observed effects. Taken together, this study demonstrated an unrecognized role of MARCH8 in negatively regulating FMT and profibrogenic responses relevant to interstitial lung diseases.NEW & NOTEWORTHY MARCH8 is an important modulator of inflammation, immunity, and other cellular processes. We found that MARCH8 expression is downregulated in the lungs of patients with idiopathic pulmonary fibrosis (IPF) and experimental models of pulmonary fibrosis. Furthermore, TGF-ß1 decreases MARCH8 transcriptionally in human lung fibroblasts (HLFs). MARCH8 overexpression blunts TGF-ß1-induced fibroblast to myofibroblast transition while knockdown of MARCH8 drives this profibrotic change in HLFs. The findings support further exploration of MARCH8 as a novel target in IPF.

Dedicator of Cytokinesis 2 (DOCK2) Deficiency Attenuates Lung Injury Associated with Chronic High-Fat and High-Fructose Diet-Induced Obesity.

Obesity is a major risk factor for lung disease development. However, little is known about the impact of chronic high-fat and high-fructose (HFHF) diet-induced obesity on lung inflammation and subsequent pulmonary fibrosis. Herein we hypothesized that dedicator of cytokinesis 2 (DOCK2) promotes a proinflammatory phenotype of lung fibroblasts (LFs) to elicit lung injury and fibrosis in chronic HFHF diet-induced obesity. An HFHF diet for 20 weeks induced lung inflammation and profibrotic changes in wild-type C57BL/6 mice. CD68 and monocyte chemoattractant protein-1 (MCP-1) expression were notably increased in the lungs of wild-type mice fed an HFHF diet. An HFHF diet further increased lung DOCK2 expression that co-localized with fibroblast-specific protein 1, suggesting a role of DOCK2 in regulating proinflammatory phenotype of LFs. Importantly, DOCK2 knockout protected mice from lung inflammation and fibrosis induced by a HFHF diet. In primary human LFs, tumor necrosis factor-α (TNF-α) and IL-1ß induced DOCK2 expression concurrent with MCP-1, IL-6, and matrix metallopeptidase 2. DOCK2 knockdown suppressed TNF-α-induced expression of these molecules and activation of phosphatidylinositol 3-kinase/AKT and NF-κB signaling pathways, suggesting a mechanism of DOCK2-mediated proinflammatory and profibrotic changes in human LFs. Taken together, these findings reveal a previously unrecognized role of DOCK2 in regulating proinflammatory phenotype of LFs, potentiation of lung inflammation, and pulmonary fibrosis in chronic HFHF diet-caused obesity.

Retrospective analysis of pulmonary cryptococcosis and extrapulmonary cryptococcosis in a chinese tertiary hospital.

Cryptococcosis is an invasive fungal disease with increased morbidity in China over the past two decades. Cryptococci can infect immunocompromised hosts as well as immunocompetent ones. In this study, we reviewed data of 71 inpatients with cryptococcosis at Ningbo First Hospital from May 2010 to May 2020 and compared the clinical profiles of pulmonary cryptococcosis (PC) and extrapulmonary cryptococcosis (EPC). Of 71 patients (38 males, 33 females), 70 were non-HIV. The annual inpatient population increased dramatically, especially in the PC group. PC was confirmed in 77.46% (55/71) of cases by pathology. The rest were EPC including intracranial infection (15.49%, 11/71) and cryptococcemia (7.04%, 5/71). Compared with PC, a larger proportion of EPC patients were found to have immunocompromised conditions judged by predisposing factors (p < 0.01), or detectable humoral or cellular immunodeficiency. Fever and headache were more common in EPC patients (p < 0.001). Patients with EPC had lower serum sodium level (p = 0.041), lower monocyte counts (p = 0.025) and higher C-reactive protein (p = 0.012). In our study, the sensitivity of cryptococcus antigen detection for EPC was 100% regardless of sample type, while serum lateral flow assay (LFA) tested negative in 25% (5/20) of PC. Immunocompromised hosts are more likely to suffer from EPC than PC.

BRD4 as a Therapeutic Target in Pulmonary Diseases.

Bromodomain and extra-terminal domain (BET) proteins are epigenetic modulators that regulate gene transcription through interacting with acetylated lysine residues of histone proteins. BET proteins have multiple roles in regulating key cellular functions such as cell proliferation, differentiation, inflammation, oxidative and redox balance, and immune responses. As a result, BET proteins have been found to be actively involved in a broad range of human lung diseases including acute lung inflammation, asthma, pulmonary arterial hypertension, pulmonary fibrosis, and chronic obstructive pulmonary disease (COPD). Due to the identification of specific small molecular inhibitors of BET proteins, targeting BET in these lung diseases has become an area of increasing interest. Emerging evidence has demonstrated the beneficial effects of BET inhibitors in preclinical models of various human lung diseases. This is, in general, largely related to the ability of BET proteins to bind to promoters of genes that are critical for inflammation, differentiation, and beyond. By modulating these critical genes, BET proteins are integrated into the pathogenesis of disease progression. The intrinsic histone acetyltransferase activity of bromodomain-containing protein 4 (BRD4) is of particular interest, seems to act independently of its bromodomain binding activity, and has implication in some contexts. In this review, we provide a brief overview of the research on BET proteins with a focus on BRD4 in several major human lung diseases, the underlying molecular mechanisms, as well as findings of targeting BET proteins using pharmaceutical inhibitors in different lung diseases preclinically.

DOCK2 Promotes Pleural Fibrosis by Modulating Mesothelial to Mesenchymal Transition.

Mesothelial to mesenchymal transition (MesoMT) is one of the crucial mechanisms underlying pleural fibrosis, which results in restrictive lung disease. DOCK2 (dedicator of cytokinesis 2) plays important roles in immune functions; however, its role in pleural fibrosis, particularly MesoMT, remains unknown. We found that amounts of DOCK2 and the MesoMT marker α-SMA (α-smooth muscle actin) were significantly elevated and colocalized in the thickened pleura of patients with nonspecific pleuritis, suggesting the involvement of DOCK2 in the pathogenesis of MesoMT and pleural fibrosis. Likewise, data from three different pleural fibrosis models (TGF-ß [transforming growth factor-ß], carbon black/bleomycin, and streptococcal empyema) consistently demonstrated DOCK2 upregulation and its colocalization with α-SMA in the pleura. In addition, induced DOCK2 colocalized with the mesothelial marker calretinin, implicating DOCK2 in the regulation of MesoMT. Our in vivo data also showed that DOCK2-knockout mice were protected from Streptococcus pneumoniae-induced pleural fibrosis, impaired lung compliance, and collagen deposition. To determine the involvement of DOCK2 in MesoMT, we treated primary human pleural mesothelial cells with the potent MesoMT inducer TGF-ß. TGF-ß significantly induced DOCK2 expression in a time-dependent manner, together with α-SMA, collagen 1, and fibronectin. Furthermore, DOCK2 knockdown significantly attenuated TGF-ß-induced α-SMA, collagen 1, and fibronectin expression, suggesting the importance of DOCK2 in TGF-ß-induced MesoMT. DOCK2 knockdown also inhibited TGF-ß-induced Snail upregulation, which may account for its role in regulating MesoMT. Taken together, the current study provides evidence that DOCK2 contributes to the pathogenesis of pleural fibrosis by mediating MesoMT and deposition of neomatrix and may represent a novel target for its prevention or treatment.

DOCK2 contributes to pulmonary fibrosis by promoting lung fibroblast to myofibroblast transition.

Idiopathic pulmonary fibrosis (IPF) is the most common chronic interstitial lung disease and is characterized by progressive scarring of the lung. Transforming growth factor-ß (TGF-ß) signaling plays an essential role in IPF and drives fibroblast to myofibroblast transition (FMT). Dedicator of cytokinesis 2 (DOCK2) is known to regulate diverse immune functions by activating Rac and has been recently implicated in pleural fibrosis. We now report a novel role of DOCK2 in pulmonary fibrosis development by mediating FMT. In primary normal and IPF human lung fibroblasts (HLFs), TGF-ß induced DOCK2 expression concurrent with FMT markers, smooth muscle α-actin (α-SMA), collagen-1, and fibronectin. Knockdown of DOCK2 significantly attenuated TGF-ß-induced expression of these FMT markers. In addition, we found that the upregulation of DOCK2 by TGF-ß is dependent on both Smad3 and ERK pathways as their respective inhibitors blocked TGF-ß-mediated induction. TGF-ß also stabilized DOCK2 protein, which contributes to increased DOCK2 expression. In addition, DOCK2 was also dramatically induced in the lungs of patients with IPF and in bleomycin, and TGF-ß induced pulmonary fibrosis in C57BL/6 mice. Furthermore, increased lung DOCK2 expression colocalized with the FMT marker α-SMA in the bleomycin-induced pulmonary fibrosis model, implicating DOCK2 in the regulation of lung fibroblast phenotypic changes. Importantly, DOCK2 deficiency also attenuated bleomycin-induced pulmonary fibrosis and α-SMA expression. Taken together, our study demonstrates a novel role of DOCK2 in pulmonary fibrosis by modulating FMT and suggests that targeting DOCK2 may present a potential therapeutic strategy for the prevention or treatment of IPF.

Synergistic influence of air temperature and vaccination on COVID-19 transmission and mortality in 146 countries or regions.

OBJECTIVE: We aimed to determine the influence of vaccination and air temperature on COVID-19 transmission and severity. METHODS: The study data in 146 countries from January 6, 2020 to July 28, 2022 were aggregated into 19,856 weeks. Country-level weekly incidence, time-varying reproduction number (Rt), mortality, and infection-fatality ratio (IFR) were compared among groups of these weeks with different vaccination rates and air temperatures. RESULTS: Weeks with <15 °C air temperature and 60% vaccination showed the highest incidence (mean, 604; SD, 855; 95% CI, 553-656, unit, /100,000 persons; N = 1073) and the highest rate of weeks with >1 Rt (mean, 41.6%; SD, 1.49%; 95% CI, 39.2-45.2%; N = 1090), while weeks with >25 °C and <20% showed the lowest incidence (mean, 24; SD, 75; 95% CI, 22-26; N = 5805) and the lowest rate of weeks with >1 Rt (mean, 15.3%; SD, 0.461%; 95% CI, 14.2-16.2%; N = 6122). Mortality in weeks with <15 °C (mean, 2.1; SD, 2.8; 95% CI, 2.0-2.2, unit, /100,000 persons; N = 4365) was five times of the mortality in weeks with >25 °C (mean, 0.44; SD, 1; 95% CI, 0.41-0.46; N = 7741). IFR ranged between 2% and 2.6% (SD, 1.9%-2.4%; 95% CI, 2.0-2.7%) at < 20% vaccination level, 1.8% (SD, 2%-2.2%; 95% CI, 1.7-2.0%) at 20-60% vaccination level, and 0.7%-1% (SD, 1%-1.8%; 95% CI, 0.7-1.1%) at > 60% vaccination level and at all air temperatures (all P < 0.001). CONCLUSIONS: Vaccination was insufficient to mitigate the transmission since the significantly elevated weekly incidence and >1 Rt rate in weeks with high vaccination, while IFR was reduced by high vaccination. Countries with long-term low air temperature were affected by high transmission and high mortality.

Serum uric acid to creatinine ratio is associated with higher prevalence of NAFLD detected by FibroScan in the United States.

BACKGROUND: The association between the serum uric acid (sUA) to creatinine ratio (sUA/Cr) and non-alcoholic fatty liver disease (NAFLD) has not been sufficiently clarified. In this study, we investigated the relationship between sUA/Cr and NAFLD among participants in the United States. METHODS: We performed a cross-sectional study based on data from the National Health and Nutrition examination Survey (NHANES) 2017-2018. A measured controlled attenuation parameter (CAP) value of ≥274 dB/m detected by Fibroscan was used to identify hepatic steatosis. SUA/Cr was calculated as sUA divided by serum creatinine. Multivariate logistic regression analysis was used to estimate the association between sUA/Cr and NAFLD. The adjusted odds ratio (OR) of sUA/Cr for NAFLD was estimated, and subgroup analysis stratified by sex was also conducted. The nonlinear relationship between sUA/Cr and NAFLD was further described using smooth curve fittings and threshold-effect analysis. RESULTS: We found that sUA/Cr was positively correlated with NAFLD status after fully adjustment for confounding factors. In subgroup analysis stratified by sex, the positive interaction between sUA/Cr and NAFLD status only existed in women but not in men. Moreover, the nonlinear association between sUA/Cr and NAFLD status was an inverted U-shaped curve with an inflection point at 9.7 among men. CONCLUSIONS: Our study identified that sUA/Cr was positively associated with the risk of NAFLD among individuals in the United States. Moreover, the correlation between sUA/Cr and NAFLD differed according to sex.

Fc-MBL-modified Fe3O4 magnetic bead enrichment and fixation in Gram stain for rapid detection of low-concentration bacteria.

Functional bacterial enrichment magnetic beads (Fe3O4@SiO2@Fc-MBL) and Gram staining were combined for the fast diagnosis of infecting bacteria in meningitis. Fe3O4@SiO2@Fc-MBL has excellent microbial binding ability and can be used for bacterial enrichment from cerebrospinal fluid (CSF). The enriched bacteria are recognized by Gram stain at very low concentrations (10 CFU·mL-1). The feasibility of this method was verified by five common bacteria in meningitis infection (Gram-positive: Staphylococcus epidermidis, Staphylococcus haemolyticus, and Staphylococcus capitis; Gram-negative: Klebsiella pneumoniae and Escherichia coli). The extraction efficiency of Fc-MBL-modified Fe3O4 magnetic beads was approximately 90% in artificial CSF for the selected bacteria, with the exception of E. coli (~ 60%). The bacteria were successfully recognized by Gram staining and microscopic observation. Fe3O4@SiO2@Fc-MBL acts by capturing and fixing the bacteria in a magnetic field throughout the experiment. Compared with traditional CSF Gram staining, this new method avoids interference by inflammatory cells and red blood cells during microscopic examination. Furthermore, the sensitivity of this method is much better than the centrifugation smear method. The whole process can be accomplished within 30 min. This novel method may have potential as a clinical tool for analysis of bacteria in the CSF.

NOX1 Promotes Mesothelial-Mesenchymal Transition through Modulation of Reactive Oxygen Species-mediated Signaling.

Pleural organization may occur after empyema or complicated parapneumonic effusion and can result in restrictive lung disease with pleural fibrosis (PF). Pleural mesothelial cells (PMCs) may contribute to PF through acquisition of a profibrotic phenotype, mesothelial-mesenchymal transition (MesoMT), which is characterized by increased expression of α-SMA (α-smooth muscle actin) and other myofibroblast markers. Although MesoMT has been implicated in the pathogenesis of PF, the role of the reactive oxygen species and the NOX (nicotinamide adenine dinucleotide phosphate oxidase) family in pleural remodeling remains unclear. Here, we show that NOX1 expression is enhanced in nonspecific human pleuritis and is induced in PMCs by THB (thrombin). 4-Hydroxy-2-nonenal, an indicator of reactive oxygen species damage, was likewise increased in our mouse model of pleural injury. NOX1 downregulation blocked THB- and Xa (factor Xa)-mediated MesoMT, as did pharmacologic inhibition of NOX1 with ML-171. NOX1 inhibition also reduced phosphorylation of Akt, p65, and tyrosine 216-GSK-3ß, signaling molecules previously shown to be implicated in MesoMT. Conversely, ML-171 did not reverse established MesoMT. NOX4 downregulation attenuated TGF-ß- and THB-mediated MesoMT. However, NOX1 downregulation did not affect NOX4 expression. NOX1- and NOX4-deficient mice were also protected in our mouse model of Streptococcus pneumoniae-mediated PF. These data show that NOX1 and NOX4 are critical determinants of MesoMT.

Rictor, an essential component of mTOR complex 2, undergoes caspase-mediated cleavage during apoptosis induced by multiple stimuli.

Caspase-mediated cleavage of proteins ensures the irreversible commitment of cells to undergo apoptosis, and is thus a hallmark of apoptosis. Rapamycin-insensitive companion of mTOR (rictor) functions primarily as a core and essential component of mTOR complex 2 (mTORC2) to critically regulate cellular homeostasis. However, its role in the regulation of apoptosis is largely unknown. In the current study, we found that rictor was cleaved to generate two small fragments at ~ 50 kD and ~ 130 kD in cells undergoing apoptosis upon treatment with different stimuli such as the death ligand, TRAIL, and the small molecule, AZD9291. This cleavage was abolished when caspases were inhibited and could be reproduced when directly incubating rictor protein and caspase-3 in vitro. Furthermore, the cleavage site of caspase-3 on rictor was mapped at D1244 (VGVD). These findings together robustly demonstrate that rictor is a substrate of caspase-3 and undergoes cleavage during apoptosis. These results add new information for understanding the biology of rictor in the regulation of cell survival and growth.

Clinical features and predictors for patients with severe SARS-CoV-2 pneumonia at the start of the pandemic: a retrospective multicenter cohort study.

BACKGROUND: This study was performed to investigate clinical features of patients with severe SARS-CoV-2 pneumonia and identify risk factors for converting to severe cases in those who had mild to moderate diseases at the start of the pandemic in China. METHODS: In this retrospective, multicenter cohort study, patients with mild to moderate SARS-CoV-2 pneumonia were included. Demographic data, symptoms, laboratory values, and clinical outcomes were collected. Data were compared between non-severe and severe patients. RESULTS: 58 patients were included in the final analysis. Compared with non-severe cases, severe patients with SARS-CoV-2 pneumonia had a longer: time to clinical recovery (12·9 ± 4·4 vs 8·3 ± 4·7; P = 0·0011), duration of viral shedding (15·7 ± 6·7 vs 11·8 ± 5·0; P = 0·0183), and hospital stay (20·7 ± 1·2 vs 14·4 ± 4·3; P = 0·0211). Multivariate logistic regression indicated that lymphocyte count was significantly associated with the rate of converting to severe cases (odds ratio 1·28, 95%CI 1·06-1·54, per 0·1 ×  109/L reduced; P = 0·007), while using of low-to-moderate doses of systematic corticosteroids was associated with reduced likelihood of converting to a severe case (odds ratio 0·14, 95%CI 0·02-0·80; P = 0·0275). CONCLUSIONS: The low peripheral blood lymphocyte count was an independent risk factor for SARS-CoV-2 pneumonia patients converting to severe cases. However, this study was carried out right after the start of the pandemic with small sample size. Further prospective studies are warranted to confirm these findings. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2000029839 . Registered 15 February 2020 - Retrospectively registered.

Differential diagnosis of coronavirus disease 2019 pneumonia or influenza A pneumonia by clinical characteristics and laboratory findings.

BACKGROUND: Pneumonia caused by the 2019 novel Coronavirus (COVID-2019) shares overlapping signs and symptoms, laboratory findings, imaging features with influenza A pneumonia. We aimed to identify their clinical characteristics to help early diagnosis. METHODS: We retrospectively retrieved data for laboratory-confirmed patients admitted with COVID-19-induced or influenza A-induced pneumonia from electronic medical records in Ningbo First Hospital, China. We recorded patients' epidemiological and clinical features, as well as radiologic and laboratory findings. RESULTS: The median age of influenza A cohort was higher and it exhibited higher temperature and higher proportion of pleural effusion. COVID-19 cohort exhibited higher proportions of fatigue, diarrhea and ground-glass opacity and higher levels of lymphocyte percentage, absolute lymphocyte count, red-cell count, hemoglobin and albumin and presented lower levels of monocytes, c-reactive protein, aspartate aminotransferase, alkaline phosphatase, serum creatinine. Multivariate logistic regression analyses showed that fatigue, ground-glass opacity, and higher level of albumin were independent risk factors for COVID-19 pneumonia, while older age, higher temperature, and higher level of monocyte count were independent risk factors for influenza A pneumonia. CONCLUSIONS: In terms of COVID-19 pneumonia and influenza A pneumonia, fatigue, ground-glass opacity, and higher level of albumin tend to be helpful for diagnosis of COVID-19 pneumonia, while older age, higher temperature, and higher level of monocyte count tend to be helpful for the diagnosis of influenza A pneumonia.

COVID-19 Transmission Within a Family Cluster by Presymptomatic Carriers in China.

We report a family cluster of coronavirus disease 2019 (COVID-19) caused by a presymptomatic case. There were 9 family members, including 8 laboratory-confirmed with COVID-19, and a 6-year-old child had no evidence of infection. Among the 8 patients, 1 adult and a 13-month-old infant were asymptomatic, and 1 adult was diagnosed as having severe pneumonia.

ERK inhibition effectively overcomes acquired resistance of epidermal growth factor receptor-mutant non-small cell lung cancer cells to osimertinib.

BACKGROUND: Osimertinib (AZD9291), a third-generation, mutation-selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (EGFR-TKI), is an approved drug for patients who have non-small cell lung cancer (NSCLC) with activating EGFR mutations or those harboring a resistant T790M mutation. Unfortunately, all patients eventually relapse and develop resistance to osimertinib. The current study addressed whether ERK inhibition exerts effects similar to those produced by MEK inhibition in overcoming acquired resistance to osimertinib. METHODS: Drug effects on cell and tumor growth were assessed by measuring cell number alterations and colony formation in vitro and with xenografts in nude mice in vivo. Apoptosis was assessed with annexin V/flow cytometry and protein cleavage. Protein alterations in cells were detected with Western blot analysis. Gene overexpression and knockout were achieved with lentiviral infection and CRISPR/Cas9, respectively. RESULTS: The combination of osimertinib with an ERK inhibitor synergistically decreased the survival of osimertinib-resistant cell lines with enhanced induction of apoptosis and effectively inhibited the growth of osimertinib-resistant xenografts in nude mice. Moreover, the combination of an MEK or ERK inhibitor with a first-generation (eg, erlotinib) or second-generation (eg, afatinib) EGFR-TKI also very effectively inhibited the growth of osimertinib-resistant cells in vitro and of tumors in vivo, although these cell lines were cross-resistant to first-generation or second-generation EGFR-TKIs. CONCLUSIONS: The current findings emphasize the importance of targeting MEK/ERK signaling in maintaining the long-term benefit of osimertinib through overcoming acquired resistance to osimertinib, warranting further investigation of this therapeutic strategy to improve the therapeutic efficacy of osimertinib in the clinic.

Overcoming acquired resistance of epidermal growth factor receptor-mutant non-small cell lung cancer cells to osimertinib by combining osimertinib with the histone deacetylase inhibitor panobinostat (LBH589).

BACKGROUND: The major clinical obstacle that limits the long-term benefits of treatment with osimertinib (AZD9291) in patients with epidermal growth factor receptor-mutant non-small cell lung cancer is the development of acquired resistance. Therefore, effective strategies that can overcome acquired resistance to osimertinib are urgently needed. The authors' current efforts in this direction have identified LBH589 (panobinostat), a clinically used histone deacetylase inhibitor, as a potential agent in overcoming osimertinib resistance. METHODS: Cell growth and apoptosis in vitro were evaluated by measuring cell numbers and colony formation and by detecting annexin V-positive cells and protein cleavage, respectively. Drug effects on tumor growth in vivo were assessed with xenografts in nude mice. Alterations of tested proteins in cells were monitored with Western blot analysis. Gene knockout was achieved using the CRISPR/Cas9 technique. RESULTS: The combination of LBH589 and osimertinib synergistically decreased the survival of different osimertinib-resistant cell lines, including those harboring C797S mutations, with greater inhibition of cell colony formation and growth. The combination enhanced the induction of apoptosis in osimertinib-resistant cells. Importantly, the combination effectively inhibited the growth of osimertinib-resistant xenograft tumors in nude mice. Mechanistically, the combination of LBH589 and osimertinib enhanced the elevation of Bim in osimertinib-resistant cells. Knockout of Bim in osimertinib-resistant cells substantially attenuated or abolished apoptosis enhanced by the LBH589 and osimertinib combination. These results collectively support a critical role of Bim elevation in the induction of apoptosis of osimertinib-resistant cells for this combination. CONCLUSIONS: The current findings provide strong preclinical evidence in support of the potential for LBH589 to overcome osimertinib resistance in the clinic.

[Recent advances in nephronectin].

Nephronectin (NPNT) is a novel extracellular matrix protein and a new ligand of integrin α8ß1. Recent studies showed that NPNT is highly expressed in kidney, lung, thyroid, etc, and it may play an important role in many pathological conditions. NPNT is involved in the process of kidney development and acute kidney injury, regulates proliferation and differentiation of osteoblast, and induces the vasculogenesis in vitro. NPNT may play a key role in pathological osteoporosis and therefore be a new therapeutic target of bone diseases. NPNT gene variants are not only associated with lung function, but also potentially implicated in chronic airway diseases development. Moreover, NPNT is also an important factor that mediates pathology of cardiac, epidermis, breast, liver and teeth diseases. In this paper, we reviewed some research progresses on the structure, distribution, physiological and pathophysiological functions of NPNT.

HMG-CoA synthase 1 is a synthetic lethal partner of BRAFV600E in human cancers.

Contributions of metabolic changes to cancer development and maintenance have received increasing attention in recent years. Although many human cancers share similar metabolic alterations, it remains unclear whether oncogene-specific metabolic alterations are required for tumor development. Using an RNAi-based screen targeting the majority of the known metabolic proteins, we recently found that oncogenic BRAFV600E up-regulates HMG-CoA lyase (HMGCL), which converts HMG-CoA to acetyl-CoA and a ketone body, acetoacetate, that selectively enhances BRAFV600E-dependent MEK1 activation in human cancer. Here, we identified HMG-CoA synthase 1 (HMGCS1), the upstream ketogenic enzyme of HMGCL, as an additional "synthetic lethal" partner of BRAFV600E Although HMGCS1 expression did not correlate with BRAFV600E mutation in human melanoma cells, HMGCS1 was selectively important for proliferation of BRAFV600E-positive melanoma and colon cancer cells but not control cells harboring active N/KRAS mutants, and stable knockdown of HMGCS1 only attenuated colony formation and tumor growth potential of BRAFV600E melanoma cells. Moreover, cytosolic HMGCS1 that co-localized with HMGCL and BRAFV600E was more important than the mitochondrial HMGCS2 isoform in BRAFV600E-expressing cancer cells in terms of acetoacetate production. Interestingly, HMGCL knockdown did not affect HMGCS1 expression levels, whereas HMGCS1 knockdown caused a compensating increase in HMGCL protein level because of attenuated protein degradation. However, this increase did not reverse the reduced ketogenesis in HMGCS1 knockdown cells. Mechanistically, HMGCS1 inhibition decreased intracellular acetoacetate levels, leading to reduced BRAFV600E-MEK1 binding and consequent MEK1 activation. We conclude that the ketogenic HMGCS1-HMGCL-acetoacetate axis may represent a promising therapeutic target for managing BRAFV600E-positive human cancers.

A novel prediction model for human papillomavirus-associated oropharyngeal squamous cell carcinoma using p16 and subcellular ß-catenin expression.

BACKGROUND: p16 overexpression is a highly sensitive yet moderately specific biomarker for predicting human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC). Nuclear ß-catenin translocation has been linked to HPV-positive OPSCC. However, whether the strategy of combining ß-catenin with p16 can better predict HPV-associated OPSCC remains unknown. METHODS: We evaluated the expression of p16 and ß-catenin (nuclear and membrane) by immunohistochemistry staining in 101 OPSCC tissues and HPV status by HPV DNA in situ hybridization. Logistic regression models were used to evaluate single or multiple biomarkers for HPV prediction. The prediction power, sensitivity, and specificity were determined by receiver operating characteristic (ROC) analyses. RESULTS: Our data showed that upon univariate analysis, p16 and nuclear ß-catenin were positively correlated with HPV status, while membrane ß-catenin was inversely correlated with HPV status (P < 0.01). p16 showed the highest HPV predictive power, with area under the curve (AUC) of 0.9074 compared to 0.6762 for nuclear ß-catenin and 0.7635 for membrane ß-catenin, respectively, indicating differential accuracies for HPV prediction. Multivariable analysis showed that p16 was significantly correlated with HPV, while nuclear and membrane ß-catenin showed marginal significance. The three-biomarker model was similarly sensitive (98.9% vs. 100%) but more specific (88.9% vs. 81%) than p16 alone, which also showed a good predictive value for overall (P = 0.0002) survival and disease-free (P = 0.0158) survival. CONCLUSION: Our study suggests a novel model of combining p16 and subcellular ß-catenin for prediction of HPV-associatred OPSCC, and this finding deserves further validation.