I2/CF3CO2Ag-mediated iodolactonization of various allenoic acids to access versatile 6- to 9-membered ring vinylic iodolactones.

Medium-sized lactones are important structural units, but their synthesis remains a great challenge. Herein, we report I2/CF3CO2Ag-mediated iodolactonization of allenoic acids to synthesize various 6- to 9-membered ring vinylic iodolactones in 16-89% yield. This protocol not only develops a new cyclization strategy of allenoic acids, but also provides highly functionalized medium-sized lactones containing alkene and halogen groups.

Overall signature of acquired KRAS gene changes in advanced non-small cell lung cancer patient with EGFR-TKI resistance.

OBJECTIVE: Numerous scattered case studies continue to demonstrate a strong correlation between acquired KRAS mutations and epidermal growth factor receptor-tyrosine kinase inhibitor resistance in non-small cell lung cancer. However, the comprehensive understanding of the KRAS pathway following the failure of epidermal growth factor receptor-tyrosine kinase inhibitor therapy remains limited. METHODS: We conducted a retrospective evaluation of the next generation sequencing data from 323 patients with advanced non-small cell lung cancer and EGFR-activating mutations after experiencing progression with epidermal growth factor receptor-tyrosine kinase inhibitor therapy. Our analysis specifically focused on the acquired changes to the KRAS gene. RESULTS: Among the 323 patients with advanced non-small cell lung cancer and EGFR-activating mutations who experienced resistance to epidermal growth factor receptor-tyrosine kinase inhibitor therapy, 14 individuals (4.3%) developed resistance due to acquired KRAS alterations. Of these 14 patients, 10 cases (71.4%) were due to KRAS missense mutations, 1 case (7.2%) was due to KRAS gene fusion and 3 cases (21.4%) were due to KRAS amplification. Notably, we identified one newly demonstrated KRAS gene fusion (KRAS and LMNTD1), one KRAS G13D and one KRAS K117N. The emergence of acquired KRAS alterations was often accompanied by novel mutations and high tumor mutation burden, with TP53, CNKN2A, PIK3CA, MYC, STK11, CDK4, BRCA2 and ERBB2 being the most frequently observed concurrent mutations. The median progression-free survival and overall survival for the 14 patients were 5.2 and 7.3 months, respectively. Acquired KRAS missense variants were associated with significantly worse progression-free survival compared with other KRAS variant subtypes (P < 0.028). CONCLUSIONS: This study provides significant evidence of the role of acquired KRAS variants in the development of resistance to epidermal growth factor receptor-tyrosine kinase inhibitor therapy. Our results contribute to the growing body of knowledge on the mutational profiles associated with resistance to epidermal growth factor receptor-tyrosine kinase inhibitor treatment. Furthermore, our study highlights the KRAS gene change as a significant mechanism of resistance to epidermal growth factor receptor-tyrosine kinase inhibitor therapy.

Tumor immune microenvironment predicts the pathologic response of neoadjuvant chemoimmunotherapy in non-small-cell lung cancer.

The clinical outcome of resectable non-small-cell lung cancer (NSCLC) patients receiving neoadjuvant chemoimmunotherapy is good but varies greatly. In addition, the pathological response after neoadjuvant chemoimmunotherapy is significantly associated with survival outcomes. The aim of this retrospective study was to identify which population of patients with locally advanced and oligometastatic NSCLC has a favorable pathological response after neoadjuvant chemoimmunotherapy. NSCLC patients treated with neoadjuvant chemoimmunotherapy were enrolled between February 2018 and April 2022. Data on clinicopathological features were collected and evaluated. Multiplex immunofluorescence was performed on pre-treatment puncture specimens and surgically resected specimens. In total, 29 patients with stages III and IV locally advanced or oligometastatic NSCLC who received neoadjuvant chemoimmunotherapy and R0 resection were enrolled. The results showed that 55% (16/29) of patients had a major pathological response (MPR) and 41% (12/29) of patients had a complete pathological response (pCR). In the stroma area of the pre-treatment specimen, the higher infiltration of CD3+ PD-L1+ tumor-infiltrating lymphocytes (TILs) and the lower infiltration of CD4+ and CD4+ FOXP3+ TILs were more likely to appear in patients with pCR. However, in the tumor area, the higher infiltration of CD8+ TILs was more likely to appear in patients with non-MPR. In the post-treatment specimen, we found increased infiltration of CD3+ CD8+ , CD8+ GZMB+ , and CD8+ CD69+ TILs and decreased infiltration of PD-1+ TILs both in the stroma and tumor areas. Neoadjuvant chemoimmunotherapy achieved an MPR rate of 55% and induced greater immune infiltration. In addition, we observed that the baseline TILs and their spatial distribution correlate to the pathological response.

Comparative Analysis on the Codon Usage Pattern of the Chloroplast Genomes in Malus Species.

Codon usage bias of coding sequences has been usually used for exploring the evolutionary factors that affect the variation of genes. We took 20 chloroplast genomes of Malus species into account to explore the codon usage patterns, including the composition, relationship between GC3s and effective number of codons, the parity rule two analyses, the relative synonymous codon usage, the codon adaptation index, the frequency of optimal codons, the codon bias index, etc., of their coding genes. The relationship between GC3 and the ENC values showed that when the separate genes are concerned, the distribution of their GC3 contents is relatively concentrated and the distribution of the ENC values are from 35 to 61 or so. The neutrality plot showed that the correlation coefficient between GC12 and GC3 is 0.095, revealing the mutation factor played a weak role in codon pattern formation. Correspondence analysis results revealed that the codon usage patterns in the chloroplast genomes of Malus species are similar. All these results showed that all Malus chloroplast genomes are AT rich ones, the third bases of the codons are affected by the natural selection pressure, the first two nucleotide base of the codon are affected by mutation pressure. Some genes, such as the rsp7, psbA and ycf2 are of lower codon usage divergences, while the rps12, rps16 and ndhD are of higher codon usage divergences. Codon usage bias exists in the Malus genomes could be used for exploring the evolutionary characteristics in chloroplast genomes and for further study on evolutionary phenomenon in other species.

Identification of miRNAs encoded by Autographa californica nucleopolyhedrovirus.

Two Autographa californica nucleopolyhedrovirus (AcMNPV) encoded miRNAs, AcMNPV-miR-1 and AcMNPV-miR-3, have been reported by us in 2013 and 2019, respectively. Here, we present an integrated investigation of AcMNPV-encoded miRNAs, which include the above two miRNAs and three additional newly identified miRNAs. Six candidate miRNAs were predicted through small RNA deep sequencing and bioinformatics, of which, five were validated. Three miRNAs are located opposite the coding sequences, the other two are located in the coding sequences of viral genes. Targets in both virus and host were predicted and subsequently tested using dual-luciferase reporter assays. The validated targets were found mainly in AcMNPV, except for the targets of AcMNPV-miR-4, which are all host genes. Based on reporter assays, the five miRNAs predominantly function by down-regulating their targets. The transcription start sites of these miRNAs were bioinformatic screened based on known baculovirus promoter motifs. Our study reveals that AcMNPV-encoded miRNAs function as fine modulators of the interactions between host and virus by regulating viral and/or host genes.

Online Multiple Athlete Tracking with Pose-Based Long-Term Temporal Dependencies.

This paper addresses the Multi-Athlete Tracking (MAT) problem, which plays a crucial role in sports video analysis. There exist specific challenges in MAT, e.g., athletes share a high similarity in appearance and frequently occlude with each other, making existing approaches not applicable for this task. To address this problem, we propose a novel online multiple athlete tracking approach which make use of long-term temporal pose dynamics for better distinguishing different athletes. Firstly, we design a Pose-based Triple Stream Network (PTSN) based on Long Short-Term Memory (LSTM) networks, capable of modeling long-term temporal pose dynamics of athletes, including pose-based appearance, motion and athletes' interaction clues. Secondly, we propose a multi-state online matching algorithm based on bipartite graph matching and similarity scores produced by PTSN. It is robust to noisy detections and occlusions due to the reliable transitions of multiple detection states. We evaluate our method on the APIDIS, NCAA Basketball and VolleyTrack databases, and the experiment results demonstrate its effectiveness.

Functional Regulation of an Autographa californica Nucleopolyhedrovirus-Encoded MicroRNA, AcMNPV-miR-1, in Baculovirus Replication.

UNLABELLED: An Autographa californica nucleopolyhedrovirus-encoded microRNA (miRNA), AcMNPV-miR-1, downregulates the ac94 gene, reducing the production of infectious budded virions and accelerating the formation of occlusion-derived virions. In the current study, four viruses that constitutively overexpress AcMNPV-miR-1 were constructed to further explore the function of the miRNA. In addition to the ac94 gene, two new viral gene targets (ac18 and ac95) of AcMNPV-miR-1 were identified, and the possible interacting proteins were verified and tested. In the context of AcMNPV-miR-1 overexpression, ac18 was slightly upregulated, and ac95 was downregulated. Several interacting proteins were identified, and a functional pathway for AcMNPV-miR-1 was deduced. AcMNPV-miR-1 overexpression decreased budded virus infectivity, reduced viral DNA replication, accelerated polyhedron formation, and promoted viral infection efficiency in Trichoplusia ni larvae, suggesting that AcMNPV-miR-1 restrains virus infection of cells but facilitates virus infection of larvae. IMPORTANCE: Recently, microRNAs (miRNAs) have been widely reported as moderators or regulators of mammalian cellular processes, especially disease-related pathways in humans. However, the roles played by miRNAs encoded by baculoviruses, which infect numerous beneficial insects and agricultural pests, have rarely been described. To explore the actions of virus-encoded miRNAs, we investigated an miRNA encoded by Autographa californica nucleopolyhedrovirus (AcMNPV-miR-1). We previously identified this miRNA through the exogenous addition of AcMNPV-miR-1 mimics. In the current study, we constitutively overexpressed AcMNPV-miR-1 and analyzed the resultant effects to more comprehensively assess what is indeed the function of this miRNA during viral infection. In addition, we widely explored the target genes for the miRNA in the viral and host genomes and proposed a possible functional network for AcMNPV-miR-1, which provides a better general understanding of virus-encoded miRNAs. In brief, our study implied that AcMNPV-miR-1 constrains viral replication and cellular infection but enhances larval infection.

miR-200b suppresses invasiveness and modulates the cytoskeletal and adhesive machinery in esophageal squamous cell carcinoma cells via targeting Kindlin-2.

To further our understanding of the pathobiology of esophageal squamous cell carcinoma (ESCC), we previously performed microRNA profiling that revealed downregulation of miR-200b in ESCC. Using quantitative real-time PCR applied to 88 patient samples, we confirmed that ESCC tumors expressed significantly lower levels of miR-200b compared with the respective adjacent benign tissues (P = 0.003). Importantly, downregulation of miR-200b significantly correlated with shortened survival (P = 0.025), lymph node metastasis (P = 0.002) and advanced clinical stage (P = 0.020) in ESCC patients. Quantitative mass spectrometry identified 57 putative miR-200b targets, including Kindlin-2, previously implicated in the regulation of tumor invasiveness and actin cytoskeleton in other cell types. Enforced expression of miR-200b mimic in ESCC cells led to a decrease of Kindlin-2 expression, whereas transfection of miR-200b inhibitor induced Kindlin-2 expression. Furthermore, transfection of miR-200b mimic or knockdown of Kindlin-2 in ESCC cells decreased cell protrusion and focal adhesion (FA) formation, reduced cell spreading and invasiveness/migration. Enforced expression of Kindlin-2 largely abrogated the inhibitory effects of miR-200b on ESCC cell invasiveness. Mechanistic studies revealed that Rho-family guanosine triphosphatases and FA kinase mediated the biological effects of the miR-200b-Kindlin-2 axis in ESCC cells. To conclude, loss of miR-200b, a frequent biochemical defect in ESCC, correlates with aggressive clinical features. The tumor suppressor effects of miR-200b may be due to its suppression of Kindlin-2, a novel target of miR-200b that modulates actin cytoskeleton, FA formation and the migratory/invasiveness properties of ESCC.

A microRNA encoded by Autographa californica nucleopolyhedrovirus regulates expression of viral gene ODV-E25.

Baculovirus-encoded microRNAs (miRNAs) have been described in Bombyx mori nucleopolyhedrovirus; however, most of their functions remain unclear. Here we report the identification and characterization of an miRNA encoded by Autographa californica nucleopolyhedrovirus. The identified miRNA, AcMNPV-miR-1, perfectly matched a segment in the coding sequence of the viral gene ODV-E25 and downregulated ODV-E25 mRNA expression, which likely resulted in a reduction of infectious budded virions and accelerated the formation of occlusion-derived virions.

Down-regulated desmocollin-2 promotes cell aggressiveness through redistributing adherens junctions and activating beta-catenin signalling in oesophageal squamous cell carcinoma.

In contrast to the well-recognized loss of adherens junctions in cancer progression, the role of desmosomal components in cancer development has not been well explored. We previously demonstrated that desmocollin-2 (DSC2), a desmosomal cadherin protein, is reduced in oesophageal squamous cell carcinoma (ESCC), and is associated with enhanced tumour metastasis and poor prognosis. Here, we report that restoration of DSC2 in ESCC cells impeded cell migration and invasion both in vitro and in vivo, whereas siRNA-mediated suppression of DSC2 expression increased cell motility. In E-cadherin-expressing ESCC cells, DSC2 restoration strengthened E-cadherin-mediated adherens junctions and promoted the localization of ß-catenin at these junctions, which indirectly inhibited ß-catenin-dependent transcription. These effects of DSC2 were not present in EC109 cells that lacked E-cadherin expression. ESCC patients with tumours that had reduced E-cadherin and negative DSC2 had poorer clinical outcomes than patients with tumours that lacked either E-cadherin or DSC2, implying that the invasive potential of ESCC cells was restricted by both DSC2 and E-cadherin-dependent junctions. Further studies revealed that DSC2 was a downstream target of miR-25. Enhanced miR-25 promoted ESCC cell invasiveness, whereas restoration of DSC2 abolished these effects. Collectively, our work suggests that miR-25-mediated down-regulation of DSC2 promotes ESCC cell aggressiveness through redistributing adherens junctions and activating beta-catenin signalling.

Inverted U-Shaped relationship between team size and citation impact: Mediating role of responsibility diffusion.

Despite the increasing prominence of research collaboration, a growing number of studies have confirmed that increasing team size can have limited performance benefits. However, the mechanism of this phenomenon has yet to be established. This study, therefore, quantified responsibility diffusion based on author contribution information and explored its mediating role in the relationship between collaboration size and citation impact (citation count in a four-year window). The results show the following: (1) An inverted U-shaped relationship exists between team size and citation count. (2) Responsibility diffusion plays a partial mediating role between team size and citation count. (3) As team size increases, the degree of responsibility diffusion increases. Lastly, (4) responsibility diffusion has an inverted U-shaped curvilinear relationship with citation count (e.g., a moderate degree of responsibility diffusion has the highest impact). These findings offer a new understanding of the mechanism by which collaboration size influences research performance. This study also has practical implications for solving research collaboration dilemmas based on a group-cognition perspective.

The increased effective connectivity from left middle occipital gyrus to right medial septum/diagonal bands in AD patients after donepezil intervention.

Introduction: Donepezil enhances the function of cholinergic nerves by increasing the concentration of acetylcholine, thereby improving clinical symptoms in patients with Alzheimer's disease (AD). However, the neural mechanisms of how donepezil modulates the effective connectivity (EC) network of cholinergic system in AD patients remain unknown. We speculated that the effective network of the cholinergic system changes in AD patients after donepezil intervention. Methods: We employed resting-state functional magnetic resonance imaging and Granger causality analysis approach to explore changes in the effective connectivity network of the basal forebrain in AD patients before and after donepezil intervention. This study included 32 participants, including 16 healthy controls (HCs) and 16 AD patients. In a 3T MRI scanner, the 16 AD patients were scanned before and after the donepezil intervention. To compare EC differences between the three groups of participants, ANOVA and post-hoc t-tests analysis were employed. Results: Compared to baseline status, AD patients after donepezil intervention had an increased EC from left middle occipital gyrus to right medial septum/diagonal bands. Compared to HCs, AD patients after donepezil intervention had an increased EC from right inferior frontal gyrus/orbit part to right medial septum/diagonal bands, AD patients before donepezil intervention had a reduced EC from right precuneus to right medial septum/diagonal bands. A significant positive correlation was found between EC values in right precuneus and Mini-Mental State Examination in pre-intervention AD patients (r = 0.7338, p = 0.0012). Discussion: Our study showed that effective connectivity of brain regions associated with the default mode network in the cholinergic pathway was enhanced after donepezil intervention. The results of this study will help us to better understand the neural mechanisms of donepezil intervention in AD and to find clinical targets for intervention.

Altered functional connectivity of the locus coeruleus in Alzheimer's disease patients with depression symptoms.

Studies have shown that functional abnormalities in the locus coeruleus (LC) are strongly associated with depressive symptoms, but the pattern of LC functional connectivity in Alzheimer's disease patients with depressive symptoms (D-AD) remains unclear. The current study aimed to investigate the characteristics of LC functional connectivity (FC) in D-AD using resting-state functional magnetic resonance imaging (rsfMRI). We obtained rsfMRI data in 24 D-AD patients (aged 66-76 years), 14 non-depressive AD patients (nD-AD) (aged 69-79 years) and 20 normal controls (aged 67-74 years) using a 3 T scanner. We used the FC approach to investigate abnormalities in the LC brain network of D-AD patients. One-way ANCOVA and post-hoc two-sample t-tests were performed to compare the strength of functional connectivity from the LC among the three groups. Our results showed that, compared with normal controls, D-AD showed decreased left LC FC with the right caudate and left fusiform gyrus, whereas nD-AD showed decreased left LC FC with the right caudate, right middle frontal gyrus and left fusiform gyrus. Compared to nD-AD, D-AD showed increased left LC FC with right superior frontal gyrus and right precentral gyrus. These findings contribute to our understanding of the neural mechanisms of D-AD.

The rational application of liquid biopsy based on next-generation sequencing in advanced non-small cell lung cancer.

BACKGROUND: Plasma and tissue biopsy have both used for targeting actionable driver gene mutations in lung cancer, whose concordance is imperfect. A reliable method to predict the concordance is urgently needed to ease clinical application. METHODS: A total of 1012 plasma samples, including 519 with paired-tissue biopsy samples, derived from lung adenocarcinoma patients were retrospectively enrolled. We assessed the associations of several clinicopathological characteristics and serum tumor markers with the concordance between plasma and tissue biopsies. RESULTS: When carcinoembryonic antigen (CEA) levels were higher than thresholds of 15.01 ng/ml and 51.15 ng/ml, the positive predictive value of concordance reached 90% and 95%, respectively. When CEA levels were lower than thresholds of 5.19 ng/ml and 3.26 ng/mL, the negative predictive value of concordance reached 45% and 50%. The performance of CYFRA21-1 in predicting concordance was similar but inferior to CEA (AUC: 0.727 vs. 0.741, p = 0.633). The performance of CEA combined with CYFRA21-1 in predicting the concordance was similar to that of the combination of independent factors derived from the LASSO regression model (AUC: 0.796 vs. 0.818, p = 0.067). CEA (r = 0.47, p < 0.01) and CYFRA21-1 levels (r = 0.45, p < 0.05) were significantly correlated with the maximum variant allele frequency, respectively. CONCLUSIONS: CEA combined with CYFRA21-1 could effectively predict the concordance between plasma and tissue biopsies, which could be used for evaluating the priority of plasma and tissue biopsies for gene testing to timely guide clinical applications in advanced lung adenocarcinoma patients.

Case Report: Durable Response to the Combination of Brigatinib and Cetuximab Plus Icotinib in a NSCLC Patient Harboring EGFR L858R-T790M-cis-G796S and L718Q Resistance Mutations Following Progression With Osimertinib.

The efficacy of osimertinib is severely limited by the emergence of EGFR C797S, which is detected in either the cis or trans position with T790M when osimertinib is used as a second-line treatment, and which is largely identified in combination with an EGFR 19 deletion. The EGFR T790M-cis-G796S mutation, which also occurs in exon 20 as C797S, participates in osimertinib resistance. To date, limited data for overcoming this resistance mutation have been reported. Here, we report data for an advanced NSCLC patient who developed EGFR L858R-T790M-cis-G796S and EGFR L718Q resistance co-mutations following progression with osimertinib. Such a case has rarely been reported, and under chemotherapy guidelines for this situation, no other effective treatment is recommended. The patient in our case experienced remarkable clinical improvement and good tolerance to the combination target therapy of brigatinib and cetuximab plus icotinib. At the time of our patient's last follow-up and prior to publication, our patient had reached more than 9 months of progression-free survival (PFS) and felt very well. Our finding provides clinical evidence that the combined target therapy of brigatinib and cetuximab may potentially be an effective treatment strategy for patients with an acquired EGFR T790M-cis-G796S resistance mutation following osimertinib treatment.

Genotyping of cerebrospinal fluid in lung cancer patients with leptomeningeal metastasis.

BACKGROUND: The prognosis of non-small-cell lung cancer (NSCLC) with leptomeningeal metastasis (LM) is poor. Detection of cell-free DNA (cfDNA) by next generation sequencing (NGS) in cerebrospinal fluid (CSF) may facilitate diagnosis of LM and identification of drug resistance mechanisms, yet its clinical use needs to be further verified. METHODS: We performed a retrospective cohort study to assess the genetic profiles of paired CSF and plasma samples in lung cancer patients with LM. Of 17 patients screened, a total of 14 patients with LM and paired NGS tests were enrolled. RESULTS: All patients harbor driver gene mutations, including 12 epidermal growth factor receptor (EGFR) activating mutations, 1 anaplastic lymphoma kinase (ALK) rearrangement, and 1 ROS-1 fusion. Genetic mutations were detected in CSF cfDNA from 92.9% patients (13/14), which was significantly higher than that from the plasma (9/14, 64.2%). The mutations were highly divergent between CSF and plasma cfDNA, with a concordance rate of 24.38% and 10 mutations shared by the two media. CSF cfDNA could also benefit the analysis of resistance mechanisms to targeted therapies. In five patients who experienced progression on 1st or 2nd generation EGFR-tyrosine kinase inhibitors (TKIs), RB1 mutation, and amplification of MET and EGFR were detected in CSF cfDNA only. In eight patients with LM progression on osimertinib resistance, EGFR amplification was detected in CSF cfDNA from four patients, whereas no CNVs were detected in the matched plasma samples. CONCLUSIONS: In conclusion, CSF could be superior to plasma in providing a more comprehensive genetic landscape of LM to find out drug resistance mechanisms and guide subsequent treatments.

Predictive value of early kinetics of ctDNA combined with cfDNA and serum CEA for EGFR-TKI treatment in advanced non-small cell lung cancer.

BACKGROUND: Circulating tumor DNA (ctDNA) has made a breakthrough as an early biomarker in operable early-stage cancer patients. However, the function of ctDNA combined with cell-free DNA (cfDNA) as a predictor in advanced non-small cell lung cancer (NSCLC) remains unknown. Here, we explored its potential as a biomarker for predicting the efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in patients with advanced NSCLC. METHODS: A retrospective analysis was undertaken. Plasma collected from 51 patients with advanced NSCLC prior to and serially after starting treatment with EGFR-TKIs was analyzed by next-generation sequencing (NGS). The performance of ctDNA, cfDNA, and combining ctDNA with cfDNA were evaluated for their ability to predict survival outcomes. RESULTS: Patients with early undetectable ctDNA and increasing cfDNA had a markedly better progression-free survival (PFS) (p < 0.001) and overall survival (OS) (p = 0.001) than those with early detectable ctDNA and decreasing cfDNA. Patients with early ctDNA clearance were more likely to have the ctDNA persistent clearance (p = 0.006). The early clearance rate of ctDNA in the normal carcinoembryonic antigen (CEA) group was significantly higher than in the low and high groups (p = 0.028). Patients with greater CEA decline had a higher early clearance rate of ctDNA than those with minor CEA change (p = 0.016). CONCLUSIONS: We based this study on ctDNA and cfDNA, explored its prognostic predictive ability, and combined CEA to monitor EGFR-TKI efficacy. This study may provide new perspectives and insights into the precise treatment strategies for NSCLC patients.

First-Line Osimertinib in Patients With EGFR-Mutated Non-Small Cell Lung Cancer: Effectiveness, Resistance Mechanisms, and Prognosis of Different Subsequent Treatments.

Background: Although the clinical application of osimertinib, a third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), has been a new step forward in the first-line treatment of non-small cell lung cancer (NSCLC), an increasing number of patients with progression on osimertinib represents a great challenge clinically. The patterns of resistance mechanisms and subsequent treatment strategies after first-line osimertinib resistance are not well established. Methods: Between January 1, 2016 and October 31, 2020, a consecutive of 56 EGFR-mutant lung cancer patients treated with osimertinib as first-line therapy at Daping Hospital (Chongqing, China) were retrospective screened. The samples of pre-osimertinib and osimertinib-resistance were all detected by next-generation sequencing (NGS) panels. Statistical analyses were carried out using SPSS 23.0 software. Survival analyses were performed using the Kaplan-Meier method and compared using a log-rank test between groups. Results: Among 47 patients with osimertinib effectiveness analysis, the median progression free survival (mPFS) was 15.4 months (95% confidence interval [CI]: 12.2-24.9 months), and median overall survival (mOS) was 35.5 months (95% CI: 23.9 months -NA). A total of 21 patients underwent repeated NGS tests upon osimertinib resistance. MET amplification was the most common resistance mechanism (6/21, 28.6%), followed by C797S mutation (5/21, 23.8%). A total of 15 patients received subsequent treatments, with mPFS of 7.3 months (95% CI 5.0 months -NA). Among them, 7 patients with EGFR C797 S or/and MET amplification received subsequent second-line targeted therapy, achieving mPFS of 7.3 months (95% CI 4.5 months -NA). Of note, 3 patients received immunotherapy as second- or third-line treatment after osimertinib resistance, achieving median clinical benefit of 37.3 months. Conclusions: MET amplification and C797S mutation are main resistance mechanisms, which could be targeted by crizotinib and gefitinib, respectively. More than 50% patients could receive subsequent anticancer targetable therapies after first-line osimertinib resistance. Immunotherapy may also be an acceptable choice after osimertinib resistance.

Effective Treatment of Lung Adenocarcinoma Harboring EGFR-Activating Mutation, T790M, and cis-C797S Triple Mutations by Brigatinib and Cetuximab Combination Therapy.

INTRODUCTION: Acquired resistance to osimertinib mediated by EGFR cis-C797S is now a growing challenge. No effective treatment strategy is currently available to overcome cis-C797S-mediated resistance. METHODS: In this retrospective cohort study, 15 patients with advanced lung adenocarcinoma and EGFR-activating mutation, T790M, and cis-C797S after osimertinib progression were identified by targeted next-generation sequencing. Five of these patients received a combined therapy of brigatinib and cetuximab, and 10 patients received cisplatin-based doublet chemotherapy. RESULTS: Among the five patients who were positive for EGFR 19del-T790M-cis-C797S mutations, and who received brigatinib and cetuximab combination therapy, three patients achieved partial response, and two had stable disease, resulting in an overall objective response rate of 60% and disease control rate of 100%. Among the 10 patients who were positive for EGFR 19del or L858R-T790M-cis-C797S mutations and received chemotherapy, only one patient achieved partial response, five had stable disease, and the other four did not benefit from chemotherapy, resulting in an overall objective response rate and disease control rate of 10% and 60%, respectively. The median progression-free survival of patients who received combined targeted therapy was 14 months, and 3 months for those treated with chemotherapy. No grade III to IV adverse events were observed in any patient. CONCLUSIONS: Our retrospective study provides clinical evidence that a combined targeted therapy of brigatinib and cetuximab could be of benefit and may potentially be an effective treatment strategy to improve survival outcomes in patients who acquire EGFR T790M-cis-C797S-mediated resistance to osimertinib.

The clinical efficacy of combinatorial therapy of EGFR-TKI and crizotinib in overcoming MET amplification-mediated resistance from prior EGFR-TKI therapy.

BACKGROUND: MET amplification is one of the EGFR-independent mechanisms of EGFR tyrosine kinase inhibitor (TKI) resistance. Combinatorial therapy of EGFR-TKI and crizotinib has been explored as a strategy to overcome resistance by simultaneously targeting both EGFR and MET pathways; however, no consensus still exists on the optimal combination regimen with the most benefit. METHODS: Retrospective analysis was performed on the clinical and sequencing data obtained from eleven patients with lung adenocarcinoma who acquired MET amplification at progression from prior EGFR-TKI therapy and received a combination of EGFR-TKI and crizotinib. RESULTS: Acquired MET amplification was detected in four and seven patients who progressed from first-line gefitinib and second-line osimertinib, respectively. Six and five patients received a combination of either first-generation (gefitinib, erlotinib, or icotinib) or third-generation (osimertinib) EGFR-TKI and crizotinib, respectively. Nine patients achieved partial response, resulting in an overall response rate of 81.8 %. The median progression-free survival of the cohort was 5.8 months. Moreover, analysis of acquired resistance mechanisms from nine patients identified EGFR T790 M from three patients who progressed from first-generation EGFR-TKI and crizotinib, while EGFR T790 M/trans-C797S and L718Q, EGFR G724S, and CCDC6-RET fusion were detected from one patient each who progressed from osimertinib and crizotinib regimen. Loss of MET amplification was also observed in a majority of the patients at progression from the combination therapy. CONCLUSIONS: Our study provides clinical evidence of the efficacy of combinatorial regimen with either first- or third-generation EGFR-TKI and crizotinib after the emergence of MET amplification-mediated EGFR-TKI resistance in patients with EGFR-mutant NSCLC.