PQR309, a dual PI3K/mTOR inhibitor, synergizes with gemcitabine by impairing the GSK-3ß and STAT3/HSP60 signaling pathways to treat nasopharyngeal carcinoma.

End-stage nasopharyngeal carcinoma (NPC) has unsatisfactory survival. The limited benefit of chemotherapy and the scarcity of targeted drugs are major challenges in NPC. New approaches to treat late-stage NPC are urgently required. In this study, we explored whether the dual PI3K/mTOR inhibitor, PQR309, exerted a favorable antineoplastic effect and sensitized the response to gemcitabine in NPC. We observed that PI3K expression was positive and elevated in 14 NPC cell lines compared with that in normal nasopharygeal cell lines. Patients with NPC with higher PI3K levels displayed poorer prognosis. We subsequently showed that PQR309 alone effectively decreased the viability, invasiveness, and migratory capability of NPC cells and neoplasm development in mice xenograft models, and dose-dependently induced apoptosis. More importantly, PQR309 remarkably strengthened the anti-NPC function of gemcitabine both in vivo and in vitro. Mechanistically, PQR309 sensitized NPC to gemcitabine by increasing caspase pathway-dependent apoptosis, blocking GSK-3ß and STAT3/HSP60 signaling, and ablating epithelial-mesenchyme transition. Thus, targeting PI3K/mTOR using PQR309 might represent a treatment option to promote the response to gemcitabine in NPC, and provides a theoretical foundation for the study of targeted drugs combined with chemotherapy for NPC.

Genomic and transcriptomic profiling of combined small-cell lung cancer through microdissection: unveiling the transformational pathway of mixed subtype.

BACKGROUND: Combined small-cell lung carcinoma (cSCLC) represents a rare subtype of SCLC, the mechanisms governing the evolution of cancer genomes and their impact on the tumor immune microenvironment (TIME) within distinct components of cSCLC remain elusive. METHODS: Here, we conducted whole-exome and RNA sequencing on 32 samples from 16 cSCLC cases. RESULTS: We found striking similarities between two components of cSCLC-LCC/LCNEC (SCLC combined with large-cell carcinoma/neuroendocrine) in terms of tumor mutation burden (TMB), tumor neoantigen burden (TNB), clonality structure, chromosomal instability (CIN), and low levels of immune cell infiltration. In contrast, the two components of cSCLC-ADC/SCC (SCLC combined with adenocarcinoma/squamous-cell carcinoma) exhibited a high level of tumor heterogeneity. Our investigation revealed that cSCLC originated from a monoclonal source, with two potential transformation modes: from SCLC to SCC (mode 1) and from ADC to SCLC (mode 2). Therefore, cSCLC might represent an intermediate state, potentially evolving into another histological tumor morphology through interactions between tumor and TIME surrounding it. Intriguingly, RB1 inactivation emerged as a factor influencing TIME heterogeneity in cSCLC, possibly through neoantigen depletion. CONCLUSIONS: Together, these findings delved into the clonal origin and TIME heterogeneity of different components in cSCLC, shedding new light on the evolutionary processes underlying this enigmatic subtype.

Real-Time Observation of Conformational Changes and Translocation of Endogenous Cytochrome c within Intact Mitochondria.

Cytochrome c (cyt c) is a multifunctional protein with varying conformations. However, the conformation of cyt c in its native environment, mitochondria, is still unclear. Here, we applied NMR spectroscopy to investigate the conformation and location of endogenous cyt c within intact mitochondria at natural isotopic abundance, mainly using widespread methyl groups as probes. By monitoring time-dependent chemical shift perturbations, we observed that most cyt c is located in the inner mitochondrial membrane and partially unfolded, which is distinct from its native conformation in solution. When suffering oxidative stress, cyt c underwent oxidative modifications due to increasing reactive oxygen species (ROS), weakening electrostatic interactions with the membrane, and gradually translocating into the inner membrane spaces of mitochondria. Meanwhile, the lethality of oxidatively modified cyt c to cells was reduced compared with normal cyt c. Our findings significantly improve the understanding of the molecular mechanisms underlying the regulation of ROS by cyt c in mitochondria. Moreover, it highlights the potential of NMR to monitor high-concentration molecules at a natural isotopic abundance within intact cells or organelles.

Real-Time NMR-Based Drug Discovery to Identify Inhibitors against Fatty Acid Synthesis in Living Cancer Cells.

Abnormal fatty acid metabolism is recognized as a key driver of tumor development and progression. Although numerous inhibitors have been developed to target this pathway, finding drugs with high specificity that do not disrupt normal cellular metabolism remains a formidable challenge. In this paper, we introduced a novel real-time NMR-based drug screening technique that operates within living cells. This technique provides a direct way to putatively identify molecular targets involved in specific metabolic processes, making it a powerful tool for cell-based drug screening. Using 2-13C acetate as a tracer, combined with 3D cell clusters and a bioreactor system, our approach enables real-time detection of inhibitors that target fatty acid metabolism within living cells. As a result, we successfully demonstrated the initial application of this method in the discovery of traditional Chinese medicines that specifically target fatty acid metabolism. Elucidating the mechanisms behind herbal medicines remains challenging due to the complex nature of their compounds and the presence of multiple targets. Remarkably, our findings demonstrate the significant inhibitory effect of P. cocos on fatty acid synthesis within cells, illustrating the potential of this approach in analyzing fatty acid metabolism events and identifying drug candidates that selectively inhibit fatty acid synthesis at the cellular level. Moreover, this systematic approach represents a valuable strategy for discovering the intricate effects of herbal medicine.

The BCL-2 inhibitor APG-2575 resets tumor-associated macrophages toward the M1 phenotype, promoting a favorable response to anti-PD-1 therapy via NLRP3 activation.

The main challenges in the use of immune checkpoint inhibitors (ICIs) are ascribed to the immunosuppressive tumor microenvironment and the lack of sufficient infiltration of activated CD8+ T cells. Transforming the tumor microenvironment (TME) from "cold" to "hot" and thus more likely to potentiate the effects of ICIs is a promising strategy for cancer treatment. We found that the selective BCL-2 inhibitor APG-2575 can enhance the antitumor efficacy of anti-PD-1 therapy in syngeneic and humanized CD34+ mouse models. Using single-cell RNA sequencing, we found that APG-2575 polarized M2-like immunosuppressive macrophages toward the M1-like immunostimulatory phenotype with increased CCL5 and CXCL10 secretion, restoring T-cell function and promoting a favorable immunotherapy response. Mechanistically, we demonstrated that APG-2575 directly binds to NF-κB p65 to activate NLRP3 signaling, thereby mediating macrophage repolarization and the activation of proinflammatory caspases and subsequently increasing CCL5 and CXCL10 chemokine production. As a result, APG-2575-induced macrophage repolarization could remodel the tumor immune microenvironment, thus improving tumor immunosuppression and further enhancing antitumor T-cell immunity. Multiplex immunohistochemistry confirmed that patients with better immunotherapeutic efficacy had higher CD86, p-NF-κB p65 and NLRP3 levels, accompanied by lower CD206 expression on macrophages. Collectively, these data provide evidence that further study on APG-2575 in combination with immunotherapy for tumor treatment is required.

Predictive value of immunotherapy-induced inflammation indexes: dynamic changes in patients with nasopharyngeal carcinoma receiving immune checkpoint inhibitors.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have achieved substantial advancements in clinical care. However, there is no strong evidence for identified biomarkers of ICIs in NPC. METHODS: In this retrospective study, 284 patients were enrolled into a training or validation cohort. Inflammatory indexes based on peripheral blood parameters were evaluated, including the systemic immune-inflammation index (SII), the neutrophil-lymphocyte ratio (NLR), the platelet-lymphocyte ratio (PLR), the lymphocyte-to-C-reactive protein ratio (LCR), and the lymphocyte-monocyte ratio (LMR). The optimum cut-off value for patient stratification was identified using X-tile. The Kaplan-Meier method and Cox's proportional regression analyses were used to identify prognostic factors. RESULTS: Immunotherapy significantly changed the levels of SII, NLR, PLR, LCR and LMR in NPC patients. Patients with lower SII, NLR, and PLR, as well as those with higher LCR and LMR, before immunotherapy had superior PFS (all p < 0.05). Moreover, PFS in the decreased SII, reduced NLR and increased LMR group was significantly longer than in the opposite group (all p < 0.05). Both univariate and multivariate analyses validated that baseline SII and LMR, and the immunotherapy-related SII reduction and LMR elevation were independent prognostic factors for PFS in advanced NPC patients receiving ICIs. CONCLUSIONS: Immune checkpoint inhibitor treatments significantly changed the levels of SII, NLR, PLR, LCR and LMR in NPC patients treated with immunotherapy. A lower baseline SII and a higher baseline LMR, and a reduction in SII and an elevation in LMR after immunotherapy are favorable factors for predicting survival among advanced NPC patients.

There is no strong evidence for identified biomarkers of immune checkpoint inhibitors (ICIs) in nasopharyngeal carcinoma (NPC).Lower baseline SII and higher baseline LMR were related to better PFS. The dynamic changes of SII and LMR were independent prognostic factors for the survival of NPC patients receiving ICIs.Neutrophils, platelets, lymphocytes, and monocytes can be used as cheap and valuable biomarkers for predicting tumor response in NPC on immunotherapy.

Machine learning for prediction of delirium in patients with extensive burns after surgery.

AIMS: Machine learning-based identification of key variables and prediction of postoperative delirium in patients with extensive burns. METHODS: Five hundred and eighteen patients with extensive burns who underwent surgery were included and randomly divided into a training set, a validation set, and a testing set. Multifactorial logistic regression analysis was used to screen for significant variables. Nine prediction models were constructed in the training and validation sets (80% of dataset). The testing set (20% of dataset) was used to further evaluate the model. The area under the receiver operating curve (AUROC) was used to compare model performance. SHapley Additive exPlanations (SHAP) was used to interpret the best one and to externally validate it in another large tertiary hospital. RESULTS: Seven variables were used in the development of nine prediction models: physical restraint, diabetes, sex, preoperative hemoglobin, acute physiological and chronic health assessment, time in the Burn Intensive Care Unit and total body surface area. Random Forest (RF) outperformed the other eight models in terms of predictive performance (ROC:84.00%) When external validation was performed, RF performed well (accuracy: 77.12%, sensitivity: 67.74% and specificity: 80.46%). CONCLUSION: The first machine learning-based delirium prediction model for patients with extensive burns was successfully developed and validated. High-risk patients for delirium can be effectively identified and targeted interventions can be made to reduce the incidence of delirium.

An overview of current research on nutritional support for burn patients: A bibliometric analysis from 1983 to 2022.

OBJECTIVES: Burn patients are reportedly prone to complications, such as skeletal muscle wasting, anemia, and slow wound healing, during treatment, due to disease and metabolic depletion, which affect prognosis. Nutritional support is essential in treating burns and can significantly improve patient survival and reduce complications such as infection. This study aimed to perform a bibliometric analysis of the existing literature on nutritional support for burns and to explore possible future research trends. METHODS: The literature related to nutritional support for burns from 1983 to 2022 was searched on Web of Science. The included literature was used for bibliometric analysis using VOSviewer and CiteSpace software. RESULTS: There were 260 publications on nutritional support for burns. The United States contributes significantly to research in this area. The United States has the highest number of publications (n = 119) and citations (n = 4424). Nutrition support was the keyword with strongest burst intensity. A diet of ≥ 60% carbohydrates and 12% to 15% fat is suitable for burn patients, but the optimal ratios have not been fully determined. CONCLUSIONS: An optimal nutritional support program is essential for treating burn patients. Individualized nutritional support programs are the trend in this field. At present, more rigorous multicenter prospective studies with large samples are needed to explore the optimal ratios for specific dietary programs, especially macronutrients, to achieve satisfactory nutritional support and improve patient prognosis.

Research progress on risk factors of delirium in burn patients: A narrative review.

Delirium, an acute brain dysfunction, is a common and serious complication in burn patients. The occurrence of delirium increases the difficulty of patient treatment, is associated with various adverse outcomes, and increases the burden on the patient's family. Many scholars have studied the factors that cause delirium, but the causes, pathogenesis, and treatment of delirium in burn patients have not been fully revealed. There is no effective pharmacological treatment for delirium, but active preventive measures can effectively reduce the incidence of delirium in burn patients. Therefore, it is necessary to study the relevant factors affecting the occurrence of delirium in burn patients. This study was conducted on December 20, 2021 by searching the PubMed database for a narrative review of published studies. The search strategy included keywords related to "burns," "delirium," and "risk factors." We reviewed the characteristics of delirium occurrence in burn patients and various delirium assessment tools, and summarized the risk factors for the development of delirium in burn patients in terms of personal, clinical, and environmental factors, and we found that although many risk factors act on the development of delirium in burn patients, some of them, such as clinical and environmental factors, are modifiable, suggesting that we can estimate the exposure of burn patients to risk factors by assessing their likelihood of delirium occurring and to make targeted interventions that provide a theoretical basis for the prevention and treatment of burn delirium.

A bibliometric analysis of publications on burn sepsis using VOSviewer.

Background: Sepsis is one of the most common complications in burn patients and causes high morbidity, especially in those with severe burns. Nevertheless, there are no formal criteria for diagnosing and treating burn sepsis. Therefore, this bibliometric analysis is applied to reveal research trends in this field and predicts its possible hot spots. Methods: We screened relevant literature on burn sepsis that met the inclusion criteria of the Web of Sciences (WOS) database and analyzed publication trends and research hot spots in related fields using VOSviewer software. Results: From 1981 to 2022, we screened 2,486 documents that met the requirements and analyzed them bibliometrically. The American scholar Herndon DN had a much higher h-index [47] than other authors. Most published, cited, and h-indexed publications are from the USA (Np: 1193, Nc: 42154, H: 98). The second most publishing country is China, but the second most cited and h-indexed country is Germany. Burns also outperforms other journals in this field (Np: 376, Nc: 8019, H: 46). "Biomarkers" is a newly emerging keyword (cluster "clinical research," APY was 2018.16), and clinically relevant research in burn sepsis maybe a future research trend. Conclusions: Sepsis in burn patients has unique pathophysiological characteristics and the general diagnostic criteria for sepsis lack specificity. Consequently, we must establish a database and construct an intelligent predictive model to help achieve a more individualized and precise early diagnosis and treatment of burn sepsis. This may also be an important development direction for future research in this field.

Prognostic effects of health-related quality of life at baseline and early change in health-related quality of life on response to treatment and survival in patients with advanced lung cancer: a prospective observational study in China.

OBJECTIVES: To investigate the relationship among baseline health-related quality of life (HRQoL), early changes in HRQoL from baseline to completion of the first cycle of chemotherapy, and prognosis in patients with advanced lung cancer. DESIGN: This was a prospective, observational study. SETTING: The study was conducted in a national cancer centre in South China. PARTICIPANTS: A total of 243 patients with chemo-naïve with advanced lung cancer were enrolled. INTERVENTION: None. PRIMARY AND SECONDARY OUTCOME MEASURES: The Functional Assessment of Cancer Therapy-Lung was used to assess HRQoL at baseline and at the end of the first cycle of chemotherapy. The Trial Outcome Index (TOI) and Lung Cancer Scale (LCS) were calculated as predictive indicators. Response to treatment was evaluated as per the Response Evaluation Criteria in Solid Tumors (RECIST) V.1.1. Survival data were gathered from follow-up to September 2019. RESULTS: Patients with 5-point or greater decreases in TOI (65% vs 48%, adjusted risk ratio (aRR)=2.19, 95% CI 1.09 to 4.41) or 2-point or greater decreases in LCS (72% vs 48%, aRR=3.29, 95% CI 1.50 to 7.22) from baseline to completion of the first cycle of chemotherapy were more likely to show stable or progressive disease than those whose HRQoL had improved. Baseline TOI ≤54 (80.0% vs 69.9%, adjusted hazard risk (aHR)=1.36, 95% CI 1.01 to 1.84) and LCS ≤21 (77.6% vs 72.5%, aHR=1.36, 95% CI 1.01 to 1.83) were associated with higher risk for death compared with TOI>54 and LCS>21. Area under the curve analysis indicated that early changes in LCS and baseline LCS scores could better predict response to treatment and overall survival than the corresponding TOI values. CONCLUSIONS: Higher pretreatment HRQoL scores could predict longer survival, while declining HRQoL values could predict unfavourable treatment outcome among patients with advanced lung cancer. The use of the LCS is recommended for the routine collection of patient-reported HRQoL. TRIAL REGISTRATION NUMBER: NCT01914120.

HIF-1α inhibition promotes the efficacy of immune checkpoint blockade in the treatment of non-small cell lung cancer.

The response to immune checkpoint inhibitors (ICIs) monotherapy remains unsatisfactory in patients with NSCLC. Thus, combining ICIs with other potential modalities is of great significance to enhance the response of single drug alone. Here, we identified that HIF-1α inhibition was capable of promoting anti-tumor immunity in NSCLC. We applied NSCLC cell lines and mouse models to evaluate the synergy of combined HIF-1α inhibition and PD-1 blockade on tumor growth and the function of tumor infiltrating lymphocytes (TILs). Public datasets were utilized to investigate patients' prognosis based on expressions of HIF-1α and LOXL2 as well as EMT-associated markers and CD8+ TILs. Moreover, we explored the correlation between HIF-1α and LOXL2 levels and CD8+ TILs in tumor samples from patients with NSCLC by immunohistochemistry, as well as their association to patients' survival. In vitro, PX-478, an HIF-1α inhibitor, promoted tumor cell apoptosis induced by T cells when combined with ICIs. Furthermore, mice treated with PX-478 and anti-PD-1 antibodies exhibited a marked delay in tumor growth and prolonged survival, which correlated with increased TILs and granzyme B secretion. Besides, patients with high HIF-1α expression exhibited high levels of EMT-related markers and low TILs, indicating an immunosuppressive phenotype. Mechanistically, we observed that HIF-1α inhibition suppressed the EMT phenotypes induced by hypoxia and further alleviated tumor immunosuppression, which was related to blockage of HIF-1α/LOXL2 signaling pathway. In summary, we identified that HIF-1α inhibition could synergize with anti-PD-1 to impair tumor growth in vitro and in vivo. Our data suggest that HIF-1α inhibitors represent a promising treatment to enhance anti-tumor immunity and provide preclinical rationale to evaluate the combination of ICIs with HIF-1α inhibition clinically in NSCLC.

Utility of comprehensive genomic profiling in directing treatment and improving patient outcomes in advanced non-small cell lung cancer.

BACKGROUND: With the identification of new targetable drivers and the recent emergence of novel targeted drugs, using comprehensive genomic profiling in lieu of the routine testing for classic drivers in the clinical care for advanced NSCLC has been increasingly advocated. However, the key assumption justifying this practice, that comprehensive genomic profiling could lead to effective anticancer therapies and improve patient outcomes, remains unproved. METHODS: Comprehensive genomic profiling was prospectively applied in 1564 advanced NSCLC patients to identify potentially actionable genomic alterations. Patients were assigned to genotype-matched targeted therapies or nonmatched therapies based on the profiling results. Its utility in directing treatments was determined by the proportion of patients receiving genotype-matched targeted therapies and the proportion of patients being enrolled into genotype-matched clinical trials. Its impacts on patient outcomes were assessed by comparing progression-free survival (PFS) and overall survival (OS) between patients who received a genotype-matched and nonmatched therapy. RESULTS: From October 2016 to October 2019, tumor genomic profiles were established in 1166 patients, leading to a matched targeted therapy in 37.7% (n = 440) and a genotype-matched trial enrollment in 20.9% of patients (n = 244). Potentially actionable alterations were detected in 781 patients (67.0%). For these patients, a genomic profiling-directed matched therapy significantly improved PFS (9.0 months vs 4.9 months, P < 0.001) and OS (3.9 years vs 2.5 years, P < 0.001) compared with a nonmatched therapy. Excluding patients with standard targeted therapies, genomic profiling led to a matched targeted therapy in 16.7% (n = 24) and a matched trial enrollment in 11.2% (n = 16) of patients. No PFS (4.7 months vs 4.6 months, P = 0.530) or OS (1.9 years vs 2.4 years, P = 0.238) benefit was observed with the use of genotype-matched targeted therapies in this population. CONCLUSIONS: Comprehensive genomic profiling is of clinical utility in assisting treatment selection, facilitating clinical trial enrollment, and improving patient outcomes in advanced NSCLC. However, for patients carrying alterations without standard-of-care targeted drugs, the interpretation of genomic profiling results should be careful given the low likelihood of benefit from the investigational or off-label use of targeted therapies in this population in the current treatment landscape. TRIAL REGISTRATION: ChiCTR1900027582 (retrospectively registered on 19 November 2019).

NMR Reveals the Conformational Changes of Cytochrome C upon Interaction with Cardiolipin.

Conformational change of cytochrome c (cyt c) caused by interaction with cardiolipin (CL) is an important step during apoptosis, but the underlying mechanism is controversial. To comprehensively clarify the structural transformations of cyt c upon interaction with CL and avoid the unpredictable alias that might come from protein labeling or mutations, the conformation of purified yeast iso-1 cyt c with natural isotopic abundance in different contents of CL was measured by using NMR spectroscopy, in which the trimethylated group of the protein was used as a natural probe. The data demonstrate that cyt c has two partially unfolded conformations when interacted with CL: one with Fe-His33 coordination and the other with a penta-coordination heme. The Fe-His33 coordination conformation can be converted into a penta-coordination heme conformation in high content of CL. The structure of cyt c becomes partially unfolded with more exposed heme upon interaction with CL, suggesting that cyt c prefers a high peroxidase activity state in the mitochondria, which, in turn, makes CL easy to be oxidized, and causes the release of cyt c into the cytoplasm as a trigger in apoptosis.

Long non-coding RNA TPT1-AS1 alleviates cell injury and promotes the production of extracellular matrix by targeting the microRNA-324-5p/CDK16 axis in human dermal fibroblasts after thermal injury.

Long non-coding RNAs (lncRNAs) are associated with the healing of burn wounds in the dermis. The present study aimed to probe the role and regulatory network of the lncRNA TPT1 antisense RNA 1 (TPT1-AS1) in human dermal fibroblasts (HDFs) following thermal injury. A model of thermally injured cells was constructed with HDFs. The levels of TPT1-AS1, microRNA (miR)-324-5p and cyclin-dependent kinase (CDK)16 were determined through reverse transcription-quantitative PCR. Cell viability, cell cycle distribution, cell apoptosis rate and extracellular matrix (ECM) synthesis were assessed with a series of in vitro gain-of-function experiments and MTT, flow cytometry and western blot analyses. The binding ability of miR-324-5p and TPT1-AS1 (or the 3' untranslated region of CDK16) was identified via bioinformatics analysis and luciferase reporter assay. It was found that TPT1-AS1 and CDK16 were downregulated, but miR-324-5p was upregulated, in the HDFs after thermal injury. TPT1-AS1 elevation induced cell viability and ECM synthesis but attenuated cell cycle arrest at the G0/G1 stage and decreased the cell apoptosis rate of thermally injured HDFs. In addition, TPT1-AS1 sponged miR-324-5p to modulate CDK16 expression. Moreover, silencing CDK16 weakened the impacts of TPT1-AS1 upregulation on cell function and ECM synthesis in heat-treated HDFs. In summary, TPT1-AS1 relieved cell injury and induced ECM synthesis by sponging miR-324-5p and targeting CDK16 in the HDFs after thermal injury, implying a protective role for TPT1-AS1 in the burn wound healing process.

Cholesterol synthesis disruption combined with a molecule-targeted drug is a promising metabolic therapy for EGFR mutant non-small cell lung cancer.

BACKGROUND: Acquired resistance is a challenge for epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer. Here, we propose a novel treatment strategy based on recent lipid metabolism work. METHODS: We applied a variety of experimental methods such as immunoblotting, MTT, si-RNA, and animal models, to demonstrate the relationship between EGFR and low-density lipoprotein receptor (LDLR) and the effects of statin monotherapy, and TKI monotherapy, and their combination on cell proliferation at the cell level and animal level. RESULTS: LDLR has a positive correlation with EGFR, EGFR signaling upregulates LDLR expression through the SREBP-1 dependent pathway, EGFR mutation cells count on lipids to survive and grow. Combined with a molecule-targeted drug, atorvastatin not only enhances the treatment effect in vitro, but also mitigates the growth of NSCLC in vivo. In this animal experiment, the combination medicine (atorvastatin with TKI) has a better tumor suppression effect on NSCLC. In HCC827 cell line, the average tumor shrinkage is about 68% in Gefitinib group, and about 49% in atorvastatin group, but about 89% in combination group. In H1975 cell line, the average tumor shrinkage is about 18% in Osimertinib group, and about 8% in atorvastatin group, but about 44% in combination group. CONCLUSIONS: the combination of an EGFR-TKI and a statin for EGFR mutant NSCLC may be a novel tumor inhibiting treatment.

PI3K-AKT-mTOR pathway alterations in advanced NSCLC patients after progression on EGFR-TKI and clinical response to EGFR-TKI plus everolimus combination therapy.

BACKGROUND: Several mechanisms including abnormal activation of PI3K-AKT-mTOR pathway have been proved to generate acquired resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC). In this study, we investigated the genomic characteristics of PI3K pathway activated in NSCLC patients after progression on EGFR-TKIs and whether both targeting EGFR and PI3K pathway could overcome resistance. METHODS: A total of 605 NSCLC cases with a history of EGFR TKI treatment were reviewed, in which 324 patients harboring EGFR mutations were confirmed progression on at least one EGFR TKI and finally enrolled. Tumor tissues or blood samples were collected at the onset of TKI progression for next generation sequencing (NGS). Six EGFR mutant patients with co-occurring mutations in PI3K pathway were retrospectively collected to assess the effect of EGFR TKI plus everolimus, a mTOR inhibitor. RESULTS: Forty-nine (14.9%) patients resistant to EGFR TKIs have at least one genetic variation in PI3K pathway. PIK3CA, PTEN and AKT1 variations were detected in 31 (9.5%), 18 (5.5%) and 3 (0.9%) of patients, respectively. No significant differences were observed in distribution of PI3K pathway alterations among patients with different EGFR mutations (EGFR exon19 deletion mutations/EGFR L858R/uncommon EGFR mutations) and among patients resistant to different EGFR TKIs. For patients treated with everolimus and EGFR-TKI, five (5/6, 83.3%) achieved stable disease (SD) and one (1/6, 16.7%) didn't receive disease control. The median progression-free survival (PFS) was 2.1 months (95% confidence interval, 1.35-4.3 months, range, 0.9-4.4 months). The most common adverse events were dental ulcer (6/6), rash (1/6). CONCLUSIONS: Our study revealed that PI3K pathway was activated in at least 14.9% in EGFR-TKI resistant patients. EGFR-TKIs plus everolimus showed limited antitumor activity in EGFR mutant NSCLC patients with PI3K pathway aberrations.

Conformational Landscapes of HER2 Exon 20 Insertions Explain Their Sensitivity to Kinase Inhibitors in Lung Adenocarcinoma.

INTRODUCTION: HER2 exon 20 insertion (ex20ins) is one of the most intractable problems in lung cancer. Most ex20ins are resistant to available EGFR or pan-HER tyrosine kinase inhibitors (TKIs), with the exception of a few mutants. However, the mechanism for TKI response and resistance of HER2 ex20ins remains poorly understood. METHODS: Next-generation sequencing-based genomic profiling data of 4139 patients with lung cancer were interrogated for HER2 ex20ins. Structural modeling and molecular dynamics simulations of common HER2 ex20ins were carried out to provide insights into the mechanism of activation and response heterogeneity of ex20ins. Molecular docking was performed to predict affinity to TKIs. Therapeutic decisions for patients were made on the basis of the results of genomic profiling. RESULTS: From 155 HER2-mutant lung cancer cases, Y772_A775dup and G778_P780dup were identified in 74 (47.7%) and 18 (11.6%) cases, respectively. Molecular dynamics simulations revealed that HER2 ex20ins led to ligand-independent kinase activation by changing the conformational landscape of HER2 kinase and restricting kinase conformation in the active state. G778_P780dup had a three-amino acid extension in the αC-ß4 loop and retained the HER2-characteristic G776 and G778. Compared with Y772_A775dup, it had less restriction on kinase conformational sampling and higher affinity to afatinib, dacomitinib, pyrotinib, and poziotinib. Treating lung adenocarcinomas carrying G778_P780dup with these inhibitors led to sustained tumor responses in six of the 10 patients. CONCLUSIONS: The kinase conformational landscape dictated by the length of the αC-ß4 loop and residues at HER2 776 and 778 position explains TKI sensitivity in ex20ins. This finding could guide therapeutic decisions with currently available therapies and future drug development strategies.