Redoxhigh phenotype mediated by KEAP1/STK11/SMARCA4/NRF2 mutations diminishes tissue-resident memory CD8+ T cells and attenuates the efficacy of immunotherapy in lung adenocarcinoma.

Metabolism reprogramming within the tumor microenvironment (TME) can have a profound impact on immune cells. Identifying the association between metabolic phenotypes and immune cells in lung adenocarcinoma (LUAD) may reveal mechanisms of resistance to immune checkpoint inhibitors (ICIs). Metabolic phenotypes were classified by expression of metabolic genes. Somatic mutations and transcriptomic features were compared across the different metabolic phenotypes. The metabolic phenotype of LUAD is predominantly determined by reductase-oxidative activity and is divided into two categories: redoxhigh LUAD and redoxlow LUAD. Genetically, redoxhigh LUAD is mainly driven by mutations in KEAP1, STK11, NRF2, or SMARCA4. These mutations are more prevalent in redoxhigh LUAD (72.5%) compared to redoxlow LUAD (17.4%), whereas EGFR mutations are more common in redoxlow LUAD (19.0% vs. 0.7%). Single-cell RNA profiling of pre-treatment and post-treatment samples from patients receiving neoadjuvant chemoimmunotherapy revealed that tissue-resident memory CD8+ T cells are responders to ICIs. However, these cells are significantly reduced in redoxhigh LUAD. The redoxhigh phenotype is primarily attributed to tumor cells and is positively associated with mTORC1 signaling. LUAD with the redoxhigh phenotype demonstrates a lower response rate (39.1% vs. 70.8%, p = 0.001), shorter progression-free survival (3.3 vs. 14.6 months, p = 0.004), and overall survival (12.1 vs. 31.2 months, p = 0.022) when treated with ICIs. The redoxhigh phenotype in LUAD is predominantly driven by mutations in KEAP1, STK11, NRF2, and SMARCA4. This phenotype diminishes the number of tissue-resident memory CD8+ T cells and attenuates the efficacy of ICIs.

Correlation of distribution characteristics and dynamic changes of gut microbiota with the efficacy of immunotherapy in EGFR-mutated non-small cell lung cancer.

BACKGROUND: The effects of gut microbiota and metabolites on the responses to immune checkpoint inhibitors (ICIs) in advanced epidermal growth factor receptor (EGFR) wild-type non-small cell lung cancer (NSCLC) have been studied. However, their effects on EGFR-mutated (EGFR +) NSCLC remain unknown. METHODS: We prospectively recorded the clinicopathological characteristics of patients with advanced EGFR + NSCLC and assessed potential associations between the use of antibiotics or probiotics and immunotherapy efficacy. Fecal samples were collected at baseline, early on-treatment, response and progression status and were subjected to metagenomic next-generation sequencing and ultra-high-performance liquid chromatography-mass spectrometry analyses to assess the effects of gut microbiota and metabolites on immunotherapy efficacy. RESULTS: The clinical data of 74 advanced EGFR + NSCLC patients were complete and 18 patients' fecal samples were dynamically collected. Patients that used antibiotics had shorter progression-free survival (PFS) (mPFS, 4.8 vs. 6.7 months; P = 0.037); probiotics had no impact on PFS. Two dynamic types of gut microbiota during immunotherapy were identified: one type showed the lowest relative abundance at the response time point, whereas the other type showed the highest abundance at the response time point. Metabolomics revealed significant differences in metabolites distribution between responders and non-responders. Deoxycholic acid, glycerol, and quinolinic acid were enriched in responders, whereas L-citrulline was enriched in non-responders. There was a significant correlation between gut microbiota and metabolites. CONCLUSIONS: The use of antibiotics weakens immunotherapy efficacy in patients with advanced EGFR + NSCLC. The distribution characteristics and dynamic changes of gut microbiota and metabolites may indicate the efficacy of immunotherapy in advanced EGFR + NSCLC.

Plasma ddPCR for the detection of MET amplification in advanced NSCLC patients: a comparative real-world study.

Background: Mesenchymal-epithelial transition (MET) amplification is a crucial oncogenic driver and a resistance mechanism to epidermal growth factor receptor tyrosine kinase inhibitors (TKIs) of non-small-cell lung cancer (NSCLC). Fluorescence in situ hybridization (FISH) is the gold standard for MET amplification detection. However, it is inapplicable when tissue samples are unavailable. Objective: This study assessed the performance of plasma droplet digital polymerase chain reaction (ddPCR) in MET amplification detection in NSCLC patients. Design and methods: A total of 87 NSCLC patients were enrolled, and 94 paired tissue and plasma samples were analyzed for the concordance between FISH and plasma ddPCR/tissue next-generation sequencing (NGS) in detecting MET amplification. In addition, the efficacy of patients with MET amplification using different detection methods who were treated with MET-TKIs was evaluated. Results: Plasma ddPCR showed substantial concordance with FISH (74.1% sensitivity, 92.5% specificity, and 87.2% accuracy with a kappa value of 0.68) and outperformed tissue NGS (kappa value of 0.64) in MET amplification detection. Combined plasma ddPCR and tissue NGS showed substantial concordance with FISH (92.3% sensitivity, 89.2% specificity, and an accuracy of 90.1% with a kappa value of 0.77). The efficacy is comparable in these NSCLC patients with MET amplification detected by FISH and plasma ddPCR who were treated with MET-TKIs. Conclusion: Plasma ddPCR is a potentially reliable method for detecting MET amplification in advanced NSCLC patients. Combined plasma ddPCR and tissue NGS might be an alternative or complementary method to MET amplification detection.

m6A-Mediated Upregulation of Imprinted in Prader-Willi Syndrome Induces Aberrant Apical-Basal Polarization and Oxidative Damage in RPE Cells.

Purpose: To reveal the clinical significance, pathological involvement and molecular mechanism of imprinted in Prader-Willi syndrome (IPW) in RPE anomalies that contribute to AMD. Methods: IPW expression under pathological conditions were detected by microarrays and qPCR assays. In vitro cultured fetal RPE cells were used to study the pathogenicity induced by IPW overexpression and to analyze its upstream and downstream regulatory networks. Results: We showed that IPW is upregulated in the macular RPE-choroid tissue of dry AMD patients and in fetal RPE cells under oxidative stress, inflammation and dedifferentiation. IPW overexpression in fetal RPE cells induced aberrant apical-basal polarization as shown by dysregulated polarized markers, disrupted tight and adherens junctions, and inhibited phagocytosis. IPW upregulation was also associated with RPE oxidative damages, as demonstrated by intracellular accumulation of reactive oxygen species, reduced cell proliferation, and accelerated cell apoptosis. Mechanically, N6-methyladenosine level of the IPW transcript regulated its stability with YTHDC1 as the reader. IPW mediated RPE features by suppressing MEG3 expression to sequester its inhibition on the AKT serine-threonine kinase (AKT)/mammalian target of rapamycin (mTOR) pathway. We also noticed that the mTOR inhibitor rapamycin suppresses the AKT/mTOR pathway to alleviate the IPW-induced RPE anomalies. Conclusions: We revealed that IPW overexpression in RPE induces aberrant apical-basal polarization and oxidative damages, thus contributing to AMD progression. We also annotated the upstream and downstream regulatory networks of IPW in RPE. Our findings shed new light on the molecular mechanisms of RPE dysfunctions, and indicate that IPW blockers may be a promising option to treat RPE abnormalities in AMD.

Allelic Context of EGFR C797X-Mutant Lung Cancer Defines Four Subtypes With Heterogeneous Genomic Landscape and Distinct Clinical Outcomes.

INTRODUCTION: EGFR C797X (C797S or C797G) mutation is the most frequent on-target mechanism of resistance to osimertinib. The hypothesis that the allelic context of C797X/T790M has implications for treatment is on the basis of sporadic reports and needs validation with larger cohorts. METHODS: We identified patients with EGFR C797X-mutant NSCLC from nine centers who progressed on osimertinib, all analyzed in a single laboratory through next-generation sequencing. We analyzed genomic profiles and assessed associations between clinical outcomes and C797X status. RESULTS: A total of 365 EGFR C797X-mutant cases were categorized into four subtypes on the basis of allelic context: in cis (75.3%), in trans (6.4%), cis&trans (10.4%), and C797X-only (7.9%). Genomically, the cis&trans subtype displayed the highest frequency of concurrent alterations at osimertinib resistance sites (21.1%), while the in cis subtype had the lowest (8.4%). Clinically, cis&trans patients exhibited the worst progression-free survival (PFS) on both previous (median 7.7 mo) and subsequent treatment (median 1.0 mo) and overall survival (median 3.9 mo). In subsequent treatments, in cis patients exhibited superior PFS with combined brigatinib and cetuximab (median 11.0 mo) compared with other regimens (p = 0.005), while in trans patients exhibited variable outcomes with combined first or second- and third-generation EGFR inhibitor (PFS range: 0.7-8.1 mo, median 2.6 mo). Notably, subtype switching was observed after subsequent treatments, predominantly toward the in cis subtype. CONCLUSIONS: Allelic context could define four EGFR C797X-mutant NSCLC subtypes with heterogeneous genetic landscapes and distinct clinical outcomes. Subsequent treatments further complicate the scenario through subtype switching.

Evolutionary overview of sarcopenia - bibliometric study on the Web of science: A review.

Sarcopenia is an age-related degenerative disease associated with adverse outcomes such as falls, functional decline, weakness, and mortality. Exploring the dynamic evolutionary path and patterns of sarcopenia research topics within a temporal framework from the perspective of strategic coordinate maps and data flow can help identify the development rules of sarcopenia themes. After searching, a total of 16,326 articles were obtained. There are few early research topics, but the development maturity of the topics is high; the number of late research topics continues to increase, showing a trend of diversified development. The differentiation and fusion of the theme evolution path are obvious, and the theme inheritance index is high. The development trend of this research field is promising. The mature and stable professional topics such as "RESISTANCE EXERCISE" and "SURVIVAL" that appeared in the late stage belong to the core topics, while newly emerging topics like "FRACTURES" and "PROTEIN" belong to the marginal topics, indicating that the research on muscle and bone metabolism in the field of sarcopenia has yet to be further in-depth, and the "CANCER" topic is a highly promising research topic with strong development potential.

Heterogeneity in the immune microenvironment of bone metastasis in driver-positive non-small cell lung cancer.

Mutations in epidermal growth factor receptor and anaplastic lymphoma kinase are common driver events in non-small cell lung cancer (NSCLC), which are associated with a high frequency of bone metastases (BMs). While the bone marrow represents a specialized immune microenvironment, the immune repertoire of BMs remains unknown. Considering the higher incidence of BMs in driver gene-positive NSCLCs, and the unique biology of the bone, herein, we assessed the infiltrating immune cells and T cell receptor (TCR) profile of BMs in driver-positive NSCLCs. Immune profile of BMs in driver gene-positive NSCLC were assessed in 10 patients, where 6 had driver gene-positive mutation. TCR and bulk RNA sequencing were performed on malignant bone samples. The diversity and clonality of the TCR repertoire were analyzed. The cellular components were inferred from bulk gene expression profiles computationally by CIBERSORT. Although BMs were generally regarded as immune-cold tumors, immune cell composition analyses showed co-existence of cytotoxic and suppressor immune cells in driver-positive BM samples, as compared to primary lung. Analysis of the TCR repertoire indicated a trend of higher diversity and similar clonality in the driver-positive compared with the driver-negative subsets. In addition, we identified two cases that showed the opposite response to immune checkpoint blockade. A comparison of these two patients' BM samples showed more highly amplified clones, fewer M2 macrophages and more activated natural killer cells in the responder. In summary, BMs in NSCLC are heterogeneous in their immune microenvironment, which might be related to differential clinical outcomes to immune checkpoint blockade.

Genomic and immune characteristics of HER2-mutated non-small-cell lung cancer and response to immune checkpoint inhibitor-based therapy.

The efficacy of immunotherapy in advanced HER2-mutated non-small-cell lung cancer (NSCLC) remains incomprehensively studied. A total of 107 NSCLC patients with de novo HER2 mutations were retrospectively studied at Guangdong Lung Cancer Institute [GLCI cohort, exon 20 insertions (ex20ins): 71.0%] to compare clinical/molecular features and immune checkpoint inhibitor (ICI)-based therapy efficacy between patients with ex20ins and non-ex20ins. Two external cohorts (TCGA, n = 21; META-ICI, n = 30) were used for validation. In the GLCI cohort, 68.2% of patients displayed programmed death-ligand 1 (PD-L1) expression < 1%. Compared with ex20ins patients, non-ex20ins patients had more concurrent mutations in the GLCI cohort (P < 0.01) and a higher tumour mutation burden in the TCGA cohort (P = 0.03). Under ICI-based therapy, advanced NSCLC patients with non-ex20ins had potentially superior progression-free survival [median: 13.0 vs. 3.6 months, adjusted hazard ratio (HR): 0.31, 95% confidence interval (CI): 0.11-0.83] and overall survival (median: 27.5 vs. 8.1 months, adjusted HR: 0.39, 95% CI: 0.13-1.18) to ex20ins patients, consistent with findings in the META-ICI cohort. ICI-based therapy may serve as an option for advanced HER2-mutated NSCLC, with potentially better efficacy in non-ex20ins patients. Further investigations are warranted in clinical practice.

Selective RET inhibitors shift the treatment pattern of RET fusion-positive NSCLC and improve survival outcomes.

PURPOSE: Rearranged during transfection (RET) fusions are important genetic drivers in non-small cell lung cancer (NSCLC). Selective RET inhibitors are setting a new paradigm in RET-driven NSCLC. However, the real-world treatment patterns, outcomes and toxicity remain largely unknown. METHODS: Data from RET fusion-positive NSCLC patients treated in our centre were retrospectively analysed. Of them, patients diagnosed before and after August 2018 were included in analysis of treatment patterns; and patients received selective RET inhibitors were eligible for analysis of adverse events (AEs). RESULTS: Patients diagnosed before August 2018 (n = 30) predominantly received chemotherapy and immunotherapy (83%) as initial therapy, while patients diagnosed after August 2018 (n = 39) mainly received selective RET inhibitors (38.5% at first-line; 50.0% at second-line). In the total 69 patients, overall survival (OS) was prolonged in patients treated with selective RET inhibitors versus untreated patients (median 34.3 versus 17.5 months; p = 0.002) during a median follow-up of 28.7 months. But there was no difference between patients treated with immunotherapy versus untreated patients. In the 38 patients received selective RET inhibition, median progression-free survival (PFS) was 11.9 months. AEs ≥ grade 3 occurred in 42.1% patients and were not associated with PFS (p = 0.63) or OS (p = 0.60). Haematological toxicity ≥ grade 3 occurred in 31.6% patients and was the leading cause of drug discontinuation. CONCLUSION: Selective RET inhibitors are increasingly being adopted into clinical practice and are associated with improved OS. However, treatment-related ≥ grade 3 AEs, especially haematologic AEs, occur frequently in real-world setting.

Applications of Circulating Tumor DNA in Immune Checkpoint Inhibition: Emerging Roles and Future Perspectives.

Immune checkpoint inhibitors (ICIs), especially anti-programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) antibodies, have made dramatic progress in the treatment of lung cancer, especially for patients with cancers not driven by oncogenes. However, responses are limited to a subset of patients, and which subset of patients will optimally benefit from ICI remains unknown. With the advantage of being minimally invasive and dynamic, noninvasive biomarkers are promising candidates to predict response, monitor resistance, and track the evolution of lung cancer during ICI treatment. In this review, we focus on the application of circulating tumor DNA (ctDNA) in plasma in immunotherapy. We examine the potential of pre- and on-treatment features of ctDNA as biomarkers, and following multiparameter analysis, we determine the potential clinical value of integrating predictive liquid biomarkers of ICIs to optimize patient management. We further discuss the role of ctDNA in monitoring treatment resistance, as well as challenges in clinical translation.

Angiotensin-(1-7), the product of ACE2 ameliorates NAFLD by acting through its receptor Mas to regulate hepatic mitochondrial function and glycolipid metabolism.

Nonalcoholic fatty liver disease (NAFLD) is the most general liver disease characterized by a continuum of liver abnormalities ranging from simple fatty liver to advanced stage of nonalcoholic steatohepatitis, cirrhosis, and even hepatocellular carcinoma. The pathological drivers of NAFLD are complex and largely undefined. It is increasingly identified that the imbalance between renin-angiotensin system and ACE2/Ang-(1-7)/Mas axis, as well as mitochondrial dysfunction associated with NAFLD. However, no known empirical research has focused on exploring the effect of the regulation of mitochondrial respiration chain activity by Ang-(1-7)/Mas on the prevention of NAFLD. Here, we evaluated the interaction and relevance of hepatic Ang-(1-7)/Mas-axis challenge with glucolipid metabolism and mitochondrial condition in vivo and in vitro. In this context, we found that Mas deletion in mice contributed to the severe glucose intolerance, insulin resistance, and hepatic steatosis which accompanied by elevated levels of serum/ hepatic alanine aminotransferase, aspartate aminotransferase, and triglycerides, as well as the mitochondrial dysfunction. Whereas forced upregulation of Mas or Ang-(1-7) administration could significantly attenuate these consequences by downregulating the expression of hepatic lipogenic proteins and enzymes for gluconeogenesis. Furthermore, activation of Ang-(1-7)/Mas arm could improve the IRS-1/Akt/AMPK pathway and enhance the mitochondrial energy utilization. Considered together, it is becoming extremely hopeful to provide a new perspective for Ang-(1-7)/Mas axis for the therapeutics of NAFLD.

Concomitant genetic alterations having greater impact on the clinical benefit of EGFR-TKIs in EGFR-mutant advanced NSCLC than BIM deletion polymorphism.

BACKGROUND: In previous studies, the predictive role of BIM deletion polymorphism with respect to responses to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) has been controversial. The potential reasons for these inconsistent findings were unknown. METHODS: Data from CTONG0901 clinical trial and medical records of Guangdong Lung Cancer Institute (GLCI) were retrospectively pooled. A total of 194 and 141 EGFR-mutant non-small cell lung cancer (NSCLC) patients treated with first- and second-generation EGFR-TKIs were examined in the CTONG0901 and GLCI cohorts, respectively. Sixty-eight patients were treated with third-generation EGFR-TKIs in the GLCI cohort. The BIM gene status was examined by next-generation sequencing. RESULTS: The frequency of BIM deletion polymorphism was 11.3% and 17.0% in CTONG0901 and GLCI cohorts, respectively. For first- and second-generation EGFR-TKIs in CTONG0901 cohort, objective response (ORR) was 54.5% in BIM deletion group versus 56.4% in wild-type BIM group (P = .87); disease control rate (DCR) was 90.9% versus 88.4% (P = 1.00); progression-free survival (PFS) was 10.5 versus 11.2 months (P = .59); and overall survival (OS) was 20.5 versus 20.5 months (P = .73). In GLCI cohort, ORR was 54.2% versus 60.7% (P = .55); DCR was 91.7% versus 96.6% (P = .27); PFS was 10.1 versus 11.6 months (P = .63); and OS was 58.5 versus 45.0 months (P = .93). For third-generation EGFR-TKIs, ORR was 18.2% versus 63.2% (P = .02); DCR was 81.8% versus 96.5%, (P = .12); PFS was 5.8 versus 9.0 months (P = .13); and OS was 30.0 versus 24.8 months (P = .85). Cox regression analysis showed that concomitant genetic alterations could adversely affect the response to EGFR-TKIs, but not BIM deletion. CONCLUSIONS: The presence of BIM deletion showed no relation to an impaired response to first-, second-, and third-generation EGFR-TKIs in NSCLC patients. The factors influencing the response of EGFR-TKIs were concomitant genetic alterations, but not BIM deletion.

Angiotensin-converting enzyme 2 regulates endoplasmic reticulum stress and mitochondrial function to preserve skeletal muscle lipid metabolism.

OBJECTIVE: Endoplasmic reticulum (ER) stress and mitochondrial function affected intramuscular fat accumulation. However, there is no clear evident on the effect of the regulation of ER stress and mitochondrial function by Angiotensin-converting enzyme 2 (ACE2) on the prevention of intramuscular fat metabolism. We investigated the effects of ACE2 on ER stress and mitochondrial function in skeletal muscle lipid metabolism. METHODS: The triglyceride (TG) content in skeletal muscle of ACE2 knockout mice and Ad-ACE2-treated db/db mice were detected by assay kits. Meanwhile, the expression of lipogenic genes (ACCα, SREBP-1c, LXRα, CPT-1α, PGC-1α and PPARα), ER stress and mitochondrial function related genes (GRP78, eIF2α, ATF4, BCL-2, and SDH6) were analyzed by RT-PCR. Lipid metabolism, ER stress and mitochondrial function related genes were analyzed by RT-PCR in ACE2-overexpression C2C12 cell. Moreover, the IKKß/NFκB/IRS-1 pathway was determined using lysate sample from skeletal muscle of ACE2 knockout mice. RESULTS: ACE2 deficiency in vivo is associated with increased lipid accumulation in skeletal muscle. The ACE2 knockout mice displayed an elevated level of ER stress and mitochondrial dysfunctions in skeletal muscle. In contrast, activation of ACE2 can ameliorate ER stress and mitochondrial function, which slightly accompanied by reduced TG content and down-regulated the expression of skeletal muscle lipogenic proteins in the db/db mice. Additionally, ACE2 improved skeletal muscle lipid metabolism and ER stress genes in the C2C12 cells. Mechanistically, endogenous ACE2 improved lipid metabolism through the IKKß/NFκB/IRS-1 pathway in skeletal muscle. CONCLUSIONS: ACE2 was first reported to play a notable role on intramuscular fat regulation by improving endoplasmic reticulum and mitochondrial function. This study may provide a strategy for treating insulin resistance in skeletal muscle.

Clinical management of third-generation EGFR inhibitor-resistant patients with advanced non-small cell lung cancer: Current status and future perspectives.

Discovery of activating mutations in epidermal growth factor receptor (EGFR) as a predictive biomarker for first-generation EGFR tyrosine kinase inhibitors (TKIs) has initiated an era of precision oncology for the treatment of advanced EGFR-mutant non-small cell lung cancer (NSCLC). Despite the robust efficacy of first- and second-generation EGFR TKIs, disease relapse is inevitable. EGFR T790M mutation is the predominant cause of disease relapse and third-generation, irreversible EGFR inhibitors designed for targeting EGFR T790M and activating mutations have demonstrated promising clinical activity and tolerability. Unfortunately, disease progression inevitably occurs and heterogenous resistance mechanisms have been reported with limited subsequent treatment strategies available. Till now, treatment approaches for patients progressed from third-generation EGFR TKIs have not been clearly established. In this review, we summarize the recent findings in resistance mechanisms to third-generation EGFR TKIs and emerging treatment approaches for EGFR-mutant patients after resistance to third-generation EGFR TKIs. We further discuss clinical challenges and future perspectives for management of EGFR-mutant patients resistant to third-generation EGFR TKIs.

Analysis of resistance mechanisms to abivertinib, a third-generation EGFR tyrosine kinase inhibitor, in patients with EGFR T790M-positive non-small cell lung cancer from a phase I trial.

BACKGROUND: Resistance to third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) presents a major clinical challenge in advanced non-small cell lung cancer (NSCLC). Here, we report resistance mechanisms to abivertinib, a novel third-generation EGFR TKI, from a phase I dose-escalation/expansion study (NCT02330367). METHODS: Patients with EGFR T790M-positive advanced NSCLC and progression on prior EGFR TKIs received abivertinib in dose escalation (50-350 mg twice daily [BID]) or expansion (300 mg BID) cohorts. Patients enrolled at Guangdong Lung Cancer Institute who underwent next-generation sequencing (NGS)-based genomic profiling upon abivertinib progression (prior to October 30, 2018) were enrolled in this exploratory analysis. FINDINGS: Thirty of 73 patients enrolled were eligible for resistance analysis. Upon abivertinib progression, 27 patients provided plasma samples (six patients also provided paired samples from the progression sites) and three patients only provided tissue samples from the progression sites for NGS. A heterogeneous landscape of resistance to abivertinib was observed: 15% (4/27) experienced EGFR T790M loss and 13% (4/30) developing EGFR tertiary mutations including C797S. EGFR amplification was observed in 11 patients (37%), and considered a putative resistance mechanism in seven (23%) patients. Other EGFR-independent resistance mechanisms involved CDKN2A, MET, PIK3CA, HER2, TP53, Rb1 and small-cell lung cancer transformation. INTERPRETATION: Our findings reveal a heterogenous pattern of resistance mechanisms to abivertinib which is distinct from that previously reported with osimertinib. EGFR amplification was the most common resistance mechanism in this cohort. FUND: The National Key R&D Program of China (Grant No. 2016YFC1303800), Key Lab System Project of Guangdong Science and Technology Department - Guangdong Provincial Key Lab of Translational Medicine in Lung Cancer (Grant No. 2012A061400006/2017B030314120).

Angiotensin-converting enzyme 2 inhibits endoplasmic reticulum stress-associated pathway to preserve nonalcoholic fatty liver disease.

BACKGROUND: Previous works indicated that the stress on the endoplasmic reticulum (ER) affected nonalcoholic fatty liver disease (NAFLD). However, there is no clear evident on the effect of the regulation of ER stress by angiotensin-converting enzyme 2 (ACE2) on the prevention of NAFLD. METHODS: HepG2 cells were treated with thapsigargin (Tg) or palmitic acid (PA). We analysed ACE2 expression using Western-blotting analyses. ER stress-related proteins were detected in ACE2 knockout mice and Ad-ACE2-treated db/db mice by immunofluorescence or Western-blotting analyses. In ACE2-overexpression HepG2 cells, the triglyceride (TG), total cholesterol (TC), and glycogen content were detected by assay kits. Meanwhile, the expression of hepatic lipogenic proteins (ACCα, SREBP-1c, FAS, and LXRα), enzymes for gluconeogenesis (PEPCK, G6Pase, and IRS2), and IKKß/NFκB/IRS1/Akt pathway were analysed by Western-blotting analyses. RESULTS: ACE2 was significantly increased in Tg/PA-induced cultured hepatocytes. Additionally, ACE2 knockout mice displayed elevated levels of ER stress, while Ad-ACE2-treated db/db mice showed reduced ER stress in liver. Furthermore, activation of ACE2 can ameliorate ER stress, accompanied by decreased TG content, increased intracellular glycogen, and downregulated expression of hepatic lipogenic proteins and enzymes for gluconeogenesis in Tg/PA-induced hepatocytes. As a consequence of anti-ER stress, the activation of ACE2 led to improved glucose and lipid metabolism through the IKKß/NFκB/IRS1/Akt pathway. CONCLUSIONS: This is the first time documented that ACE2 had a notable alleviating role in ER stress-induced hepatic steatosis and glucose metabolism via the IKKß/NFκB/IRS1/Akt-mediated pathway. This study may further provide insight into a novel underlying mechanism and a strategy for treating NAFLD.

EGFR L792H and G796R: Two Novel Mutations Mediating Resistance to the Third-Generation EGFR Tyrosine Kinase Inhibitor Osimertinib.

BACKGROUND: The third-generation EGFR tyrosine kinase inhibitor osimertinib has been approved in many countries to treat advanced NSCLC in patients with the EGFR T790M mutation. As the development of acquired resistance is inevitable, it is urgent that the mechanisms of such resistance be clarified. METHODS: DNA samples from a cohort of 340 patients with lung adenocarcinoma who were taking osimertinib were subjected to next-generation sequencing and screened in terms of the frequencies of the L792H and G796R mutations. Ba/F3 cells stably expressing the EGFR L858R/T790M mutations (in cis) with either the L792H or G796R mutation were created to investigate the impact of the two novel mutations on EGFR tyrosine kinase inhibitors and other potential drug combinations in vitro. Structural analyses were performed by using Schrödinger/Maestro software (version 11.1.012, Schrödinger LLC, Cambridge, MA). RESULTS: L792H and G796R were detected in 1.76% (six of 340) and 0.56% (two of 340) patients with lung adenocarcinoma treated with osimertinib, respectively. The introduction of L792H or G796R mutations against an L858R/T790M background caused dramatic reductions in osimertinib sensitivity. Structural modeling showed that mutations in cis with T790M either forced the ligand (osimertinib) to rotate out (breaking the binding) or pulled the hinge loop (breaking the hinge). Various other drug combinations. including cetuximab with EAI045, failed to inhibit either cis mutant effectively. CONCLUSIONS: The EGFR L858R/T790M/L792H and L858R/T790M/G796R mutations conferred resistance to osimertinib both in vitro and in silico. For patients in whom the two resistance mutations occur at low frequency, more precise treatment strategies and additional combinational approaches are required.

Liquid biopsy in non-small cell lung cancer: a key role in the future of personalized medicine?

INTRODUCTION: Liquid biopsies, especially the analysis of circulating tumor DNA (ctDNA), as a novel and non-invasive method for the diagnosis and monitoring of non-small cell lung cancer (NSCLC) have already been implemented in clinical settings. The majority of ctDNA is released from apoptotic or necrotic tumor cells, thus reflecting the genetic profile of a tumor. Numerous studies have reported a high concordance in mutation profiles derived from liquid biopsy and tissue biopsy, especially in driver genes. Liquid biopsy could overcome the clonal heterogeneity of tumour biopsy, as it provides a single snapshot of a tumour tissue. Moreover, non-invasiveness is the biggest advantage for liquid biopsy, and the procedure can be repeatedly performed during the treatment for the purpose of monitoring. Therefore, ctDNA could act as a potential complementary method for tissue biopsies in diagnosis, prognostic, treatment response and resistance. Areas covered: This review summarizes the recent advancements in liquid biopsy with a focus on NSCLC, including its applications and technologies associated with assessing ctDNA. The authors conclude the review by discussing the challenges associated with liquid biopsy. Expert commentary: The analysis of ctDNA represents a promising method for liquid biopsy, which will be a novel and potentially complementary method in diagnosis, treatment and prognostic in NSCLC at all stages.

The emerging roles of NGS-based liquid biopsy in non-small cell lung cancer.

The treatment paradigm of non-small cell lung cancer (NSCLC) has evolved into oncogene-directed precision medicine. Identifying actionable genomic alterations is the initial step towards precision medicine. An important scientific progress in molecular profiling of NSCLC over the past decade is the shift from the traditional piecemeal fashion to massively parallel sequencing with the use of next-generation sequencing (NGS). Another technical advance is the development of liquid biopsy with great potential in providing a dynamic and comprehensive genomic profiling of NSCLC in a minimally invasive manner. The integration of NGS with liquid biopsy has been demonstrated to play emerging roles in genomic profiling of NSCLC by increasing evidences. This review summarized the potential applications of NGS-based liquid biopsy in the diagnosis and treatment of NSCLC including identifying actionable genomic alterations, tracking spatiotemporal tumor evolution, dynamically monitoring response and resistance to targeted therapies, and diagnostic value in early-stage NSCLC, and discussed emerging challenges to overcome in order to facilitate clinical translation in future.