Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors Research Articles

Plasma metabolomics profiling of EGFR-mutant NSCLC patients treated with third-generation EGFR-TKI

Third-generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are the latest and a vital treatment option for non-small cell lung cancer (NSCLC) patients. Although EGFR-sensitive mutations are an indication for third-generation EGFR-TKI therapy, 30% of NSCLC patients lack response and all patients inevitably progress. There is a lack of biomarkers to predict the efficacy of EGFR-TKI therapy. In this report, we performed comprehensive plasma metabolomic profiling on 186 baseline and 20 post-treatment samples, analyzing 1,019 metabolites using four ultrahigh performance liquid chromatography-tandem mass spectroscopy (UPLC-MS/MS) methods. The dataset contains detailed clinical and metabolic information for 186 patients. Rigorous quality control measures were implemented. No significant differences in body mass index and biochemical metabolic parameters were observed between responders and non-responders. The datasets were utilized to characterize the responsive metabolic traits of third-generation EGFR-TKI therapy. All datasets are available for download on the OMIX website. We anticipate that these datasets will serve as valuable resources for future studies investigating NSCLC metabolism and for the development of personalized therapeutic strategies.

PFKFB3-dependent redox homeostasis and DNA repair support cell survival under EGFR-TKIs in non-small cell lung carcinoma

BackgroundThe efficacy of tyrosine kinase inhibitors (TKIs) targeting the EGFR is limited due to the persistence of drug-tolerant cell populations, leading to therapy resistance. Non-genetic mechanisms, such as metabolic rewiring, play a significant role in driving lung cancer cells into the drug-tolerant state, allowing them to persist under continuous drug treatment.MethodsOur study employed a comprehensive approach to examine the impact of the glycolytic regulator 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB3) on the adaptivity of lung cancer cells to EGFR TKI therapies. We conducted metabolomics to trace glucose rerouting in response to PFKFB3 inhibition during TKI treatment. Live cell imaging and DCFDA oxidation were used to quantify levels of oxidation stress. Immunocytochemistry and Neutral Comet assay were employed to evaluate DNA integrity in response to therapy-driven oxidative stress.ResultsOur metabolic profiling revealed that PFKFB3 inhibition significantly alters the metabolic profile of TKI-treated cells. It limited glucose utilization in the polyol pathway, glycolysis, and TCA cycle, leading to a depletion of ATP levels. Furthermore, pharmacological inhibition of PFKFB3 overcome TKI-driven redox capacity by diminishing the expression of glutathione peroxidase 4 (GPX4), thereby exacerbating oxidative stress. Our study also unveiled a novel role of PFKFB3 in DNA oxidation and damage by controlling the expression of DNA-glycosylases involved in base excision repair. Consequently, PFKFB3 inhibition improved the cytotoxicity of EGFR-TKIs by facilitating ROS-dependent cell death.ConclusionsOur results suggest that PFKFB3 inhibition reduces glucose utilization and DNA damage repair, limiting the adaptivity of the cells to therapy-driven oxidative stress and DNA integrity insults. Inhibiting PFKFB3 can be an effective strategy to eradicate cancer cells surviving under EGFR TKI therapy before they enter the drug-resistant state. These findings may have potential implications in the development of new therapies for drug-resistant cancer treatment.

Postoperative adjuvant therapy with molecularly targeted agents for non-small cell lung cancer.

The efficacy of molecularly targeted agents has been established in advanced lung cancer, and their indications have recently expanded to include perioperative treatment of resectable lung cancer. For epidermal growth factor receptor (EGFR) mutation-positive patients, postoperative adjuvant therapy with EGFR-tyrosine kinase inhibitors (EGFR-TKIs) is available in Japan following the results of the ADAURA trial. In addition to EGFR-TKIs, postoperative adjuvant therapy with TKIs targeting anaplastic lymphoma kinase (ALK) and rearranged during transfection (RET) is expected to be established. On the other hand, because adjuvant chemotherapy is ineffective in patients who have been completely cured of cancer through surgery alone, the balance between efficacy and adverse effects must be considered, and further studies will be needed to determine the necessary and sufficient dosage and the appropriateduration of administration. In addition, the cost of adjuvant chemotherapy has recently become an issue that cannot be overlooked. Therefore, it will be imperative to develop biomarkers to effectively narrow down the patients who benefit from adjuvant chemotherapy.

Persist or resist: Immune checkpoint inhibitors in EGFR-mutated NSCLC.

Although epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), especially third-generation TKIs, have significantly improved the progression-free survival and overall survival of non-small cell lung cancer (NSCLC) patients with EGFR mutation, TKI resistance is inevitable for most patients. Over the past few years, immune checkpoint inhibitors (ICIs) have significantly improved the survival for EGFR-wild type NSCLC patients. However, no significantly improved benefits were observed with ICI monotherapy in EGFR-mutated patients. EGFR-mutated NSCLC shows more heterogeneity in tumor mutational burden (TMB), programmed cell death-ligand 1 (PD-L1), and immune microenvironment characteristics. Whether ICIs are suitable for EGFR-mutated NSCLC patients remains to be elucidated. In this review, we summarized clinical trials of ICIs or combined therapy in EGFR-mutated NSCLC patients. We further discussed the factors determining the efficacy of ICIs in EGFR-mutated NSCLC patients, the mutation subtypes and microenvironment characteristics of potential responders. More importantly, we provided insights into areas worth further investigation in the future.

The Resistance to EGFR-TKIs in Non-Small Cell Lung Cancer

Lung cancer has emerged as a highly aggressive malignancy posing a significant global health hazard, with a particular concern for the rising incidence and mortality of gene-altered non-small cell lung cancer (NSCLC). As the prevalence of NSCLC rises, the investigation and selection of tumor treatment techniques are gaining significance. The treatment of individuals with genetic mutations in advanced NSCLC has emphasized the application of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). Early and subsequent generations of EGFR-TKIs have demonstrated clinical efficacy in NSCLC patients carrying select genetic alterations. Osimertinib, a third-generation EGFR-TKI, has been sanctioned as the standard first-line therapy and is also utilized as a second-line option for individuals who develop the T790M resistance mutation following prior EGFR-TKI treatment. Approximately 10 to 30 percent of patients diagnosed with NSCLC exhibit EGFR mutations. This leads to abnormal activation of cancer genes and inactivation of tumor suppressor genes, resulting in poor prognosis for patients. This paper aims to analyze the development and resistance processes of EGFR inhibitors, thereby enhancing the comprehension of the resistance pathways to EGFR-TKIs.

Efficacy and safety of lenvatinib plus gefitinib in lenvatinib-resistant hepatocellular carcinomas: a prospective, single-arm exploratory trial

Lenvatinib, a multi-kinase inhibitor, has been approved as first-line treatment for advanced hepatocellular carcinoma (HCC), but its efficacy is limited. We have shown previously that lenvatinib and epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) combination therapy overcomes lenvatinib resistance in HCC with high level of EGFR expression (EGFRhigh). We present here the results of a single-arm, open-label, exploratory study of lenvatinib plus the EGFR-TKI gefitinib for patients with HCC resistance to lenvatinib (NCT04642547; n = 30). Only patients with EGFRhigh HCC and progressive disease after lenvatinib treatment were recruited in the study. The most frequent adverse events of all grades were fatigue (27 patients; 90%), followed by rash (25 patients; 83.3%), diarrhea (24 patients; 80%), and anorexia (12 patients; 40%). Among 30 patients, 9 (30%) achieved a confirmed partial response and 14 (46.7%) had stable disease according to mRECIST criteria. Based on RECIST1.1, 5 (16.7%) achieved a confirmed partial response and 18 (60%) had stable disease. The estimated median progression free survival (PFS) and overall survival (OS) time were 4.4 months (95% CI: 2.5 to 5.9) and13.7 months (95% CI: 9.0 to NA), respectively. The objective response rate (ORR) of the patients in the present study compares very favorable to that seen for the two approved second line treatments for HCC (cabozantinib ORR of 4%; regorafenib ORR of 11%). Given that this combination was well-tolerated, a further clinical study of this combination is warranted.

Osimertinib exacerbates immune checkpoint inhibitor-related severe adverse events by activating the IL-6/JAK/STAT3 pathway in macrophages.

The combination of epithelial growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) and immune checkpoint inhibitors (ICIs) leads to an increased incidence of severe immune-related adverse events (irAEs). However, the mechanisms underlying macrophages in irAEs have not been elucidated. An osimertinib and ICI-induced irAE mouse model was constructed. Lung micro-CT scans were used to assess the degree of inflammatory infiltration. Hematoxylin-eosin staining was used to analyze the histopathologic inflammatory infiltration in mouse liver and lung tissues. Flow cytometry was used to detect the percentages of T cells, NK cells, and macrophages and the expression of EGFR. Enzyme-linked immunosorbent assay (ELISA) was used to detect the serum interleukin (IL)-6, alanine transaminase (ALT), ferritin, and tumor necrosis factor (TNF)-α levels. Total RNA extracted from mouse liver macrophages was analyzed by RNA-seq. Simple Western blot analysis was used to detect the IL-6/JAK/STAT3 pathway activation state. Osimertinib combined with ICIs upregulated EGFR expression on macrophages with increased serum IL-6, ALT, and ferritin levels. RNA-seq and simple Western blot analysis of mouse liver macrophages confirmed that that the IL-6/JAK/STAT3 pathway was activated in the combination treatment group. Ruxolitinib blocked the IL-6/JAK/STAT3 pathway and significantly decreased the serum IL-6, ALT, and ferritin levels in the combination treatment group. An osimertinib and ICI-induced irAE mouse model was constructed that showed osimertinib combined with ICIs inhibited EGFR phosphorylation and activated the IL-6/JAK/STAT3 signaling pathway in mouse liver macrophages, which led to the release of relevant cytokines.

Real-World Study of EGFR-TKI Rechallenge With Another TKI After First-Line Osimertinib Discontinuation in Patients With EGFR-Mutated Non-Small Cell Lung Cancer: A Subset Analysis of the Reiwa Study.

First-line osimertinib is widely used to treat patients with epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancers (NSCLC). In clinical practice, rechallenge therapy with another EGFR-tyrosine kinase inhibitor (TKI) is often performed after first-line TKI discontinuation owing to resistance or toxicity; however, the efficacy and toxicity of EGFR-TKI rechallenge after first-line osimertinib have not been adequately investigated. This study aimed to examine the efficacy and safety of EGFR-TKI rechallenge with another TKI. This multicenter prospective observational study enrolled patients with EGFR-mutated NSCLC who received first-line osimertinib and another EGFR-TKI as second- or third-line treatment between September 2018 and August 2020. Fifty-three patients received rechallenge with another EGFR-TKI in the second-line (n = 38, 71.7%) or third-line (n = 15, 28.3%) setting. The primary reason for first-line osimertinib discontinuation was toxicity in 32 (60.4%, 17 patients with pneumonitis) and disease progression in 20 (37.7%) patients. The most common rechallenge EGFR-TKI was afatinib (n = 24, 45.3%), followed by gefitinib (n = 16, 30.2%) and erlotinib (n = 8, 15.1%). The real-world time to treatment failure (rwTTF) was 7.3 months. The rwTTF for the toxicity discontinuation and progressive disease discontinuation groups was 9.3 months and 5.1 months, respectively, (HR 1.61, p = 0.119). EGFR-TKI rechallenge was discontinued due to toxicity in nine patients (17.0%), but no patient developed pneumonitis. EGFR-TKI rechallenge with another TKI is well tolerated in patients with EGFR-mutated NSCLC. Thus, it may be a useful treatment option after first-line osimertinib failure, especially after osimertinib discontinuation due to toxicity.

CXCR1+ neutrophil infiltration orchestrates response to third-generation EGFR-TKI in EGFR mutant non-small-cell lung cancer

Although third-generation Epidermal growth factor receptor—tyrosine kinase inhibitors (EGFR-TKI) is standard of care for patients with EGFR-mutant Non-small cell lung cancer (NSCLC), little is known about the predictors of response or resistance. Here, we integrated single-cell RNA (scRNA) sequencing, bulk RNA sequencing, multiplexed immunofluorescence and flow cytometry data from pretreatment and post-resistant tumor samples of EGFR-mutant NSCLC patients received third-generation EGFR-TKIs. We show that resistant samples had a markedly enriched CXCR1+ neutrophils infiltration (P < 0.01) than pretreatment samples, which were distinguished from other subtypes of neutrophils and displayed immunosupressive characteristics. Spatial analysis showed that increased CXCR1+ neutrophils predominantly infiltrated into the tumor core in resistant samples and the average distance of neutrophils to tumor cells markedly reduced from 33 to 19 μm. Deep analysis of scRNA and bulk RNA sequencing data revealed the increased interactions between CXCR1+ neutrophils and tumor cells and activated TNF-α/NF-κB signaling pathway in tumor cells of resistant samples. In vitro and in vivo experiments validated that CXCR1+ neutrophils resulted in resistance to third-generation EGFR-TKI via activating TNF-α/NF-κB signaling pathway in tumor cells. Importantly, patients with low pretreatment CXCR1+ neutrophil infiltration abundance had a dramatically longer progression-free survival (11.8 vs. 7.5 months; P = 0.019) and overall survival (33.0 vs. 23.5 months; P = 0.029) than those with high infiltration abundance. Collectively, these findings suggest that CXCR1+ neutrophils infiltration was associated with the efficacy of third-generation EGFR-TKI in patients with EGFR-mutant NSCLC.

Comparison of treatment regimens for unresectable stage III epidermal growth factor receptor (EGFR)mutant non-small cell lung cancer.

Durvalumab after chemoradiotherapy (CRT) failed to bring survival benefits to patients with epidermal growth factor receptor (EGFR) mutations in PACIFIC study ( evaluating durvalumab in patients with stage III, unresectable NSCLC who did not have disease progression after concurrent chemoradiotherapy). We aimed to explore whether locally advanced inoperable patients with EGFR mutations benefit from tyrosine kinase inhibitors (TKIs) and the optimal treatment regimen. We screened the PubMed, Embase, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov databases from January 1, 2000 to December 31, 2022 and performed a meta-analysis based on a Bayesian framework, with progression-free survival (PFS) and overall survival (OS) as the primary endpoints. A total of 1156 patients were identified in 16studies that included 6 treatment measures, including CRT, CRT followed by durvalumab (CRT-Durva), TKI monotherapy, radiotherapy combined with TKI (RT-TKI), CRT combined with TKI (CRT-TKI), and TKI combined with durvalumab (TKI-Durva). The PFS after the TKI-containing treatments was significantly longer than after the TKI-free treatments (hazard ratio [HR]=0.37, 95% confidence interval [CI],0.20-0.66). The PFS of TKI monotherapy was significantly longer than CRT (HR=0.66, 95% CI, 0.50-0.87) but shorter than RT-TKI (HR=1.78, 95% CI,1.17-2.67). Furthermore, the PFS of RT-TKI or CRT-TKI were both significantly longer than that of CRT or CRT-Durva. RT-TKI ranked first in the Bayesian ranking, with the longest OS (60.8months, 95% CI=37.2-84.3 months) and the longest PFS (21.5months, 95% CI,15.4-27.5 months) in integrated analysis. For unresectable stage III EGFR mutant NSCLC, RT and TKI are both essential. Based on the current evidence, RT-TKI brings the best survival advantage, while CRT-TKI needs further estimation. Large randomized clinical trials are urgently needed to explore the appropriate application sequences of TKI, radiotherapy, and chemotherapy. PROSPERO; https://www.crd.york.ac.uk/PROSPERO/; No. CRD42022298490.

Ivacaftor, a CFTR potentiator, synergizes with osimertinib against acquired resistance to osimertinib in NSCLC by regulating CFTR-PTEN-AKT axis.

Osimertinib, a third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), has demonstrated significant clinical benefits in the treatment of EGFR-mutated non-small cell lung cancer (NSCLC). However, inevitable acquired resistance to osimertinib limits its clinical utility, and there is a lack of effective countermeasures. Here, we established osimertinib-resistant cell lines and performed drug library screening. This screening identified ivacaftor, a cystic fibrosis transmembrane conductance regulator (CFTR) potentiator, as a synergistic enhancer of osimertinib-induced anti-tumor activity both in vitro and in vivo. Mechanistically, ivacaftor facilitated the colocalization of CFTR and PTEN on the plasma membrane to promote the function of PTEN, subsequently inhibiting the PI3K/AKT signaling pathway and suppressing tumor growth. In summary, our study suggests that activating CFTR enhances osimertinib-induced anti-tumor activity by regulating the PTEN-AKT axis. Furthermore, ivacaftor and osimertinib constitute a potential combination strategy for treating osimertinib-resistant EGFR-mutated NSCLC patients.

Revolutionizing NSCLC Treatment: Immunotherapy Strategies for EGFR-TKIs Resistance.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are the standard treatment choice for advanced non-small cell lung cancer (NSCLC) patients with EGFR mutations. EGFR-TKIs have made significant progress in the treatment of advanced NSCLC patients, but drug resistance issues still inevitably arise. The mechanism of drug resistance and subsequent treatment has been current research challenge and priority. Immune checkpoint inhibitors (ICIs) are a new choice for late-stage NSCLC patients without druggable molecular alterations. Currently, several studies have applied ICIs therapy for NSCLC patients with EGFR-TKIs resistance and explored the potential efficacy of ICIs. This review elaborates on the current status of immunotherapy after EGFR-TKIs resistance, including ICIs monotherapy, combined with EGFR-TKIs, chemotherapy, antiangiogenic drugs, and other therapies.

Clinical and Preclinical Activity of EGFR Tyrosine Kinase Inhibitors in Non-Small-Cell Lung Cancer Harboring BRAF Class 3 Mutations.

Patients with tumors harboring BRAF class 3 mutations lack targeted therapies. These mutations are characterized by low/absent BRAF kinase domain activation and are believed to amplify already active RAS signaling, potentially triggered by receptor tyrosine kinases like EGFR. Two patients with BRAF class 3-mutated metastatic non-small-cell lung cancer (NSCLC) were treated with erlotinib at our Institution after failure of standard therapies. Two cell lines were established from patients with BRAF class 3-mutated NSCLC, and their sensitivity to EGFR tyrosine kinase inhibitors (EGFR-TKIs) was assessed using EGFR-mutated, BRAF class 1 and 2-mutated, and KRAS-mutated NSCLC cell lines as controls. Patient 1, a 60-year-old male with BRAFD594N-mutated NSCLC, achieved complete response to erlotinib after progression on first- and second-line chemotherapy. Patient 2, a 60-year-old female with BRAFD594G-mutated NSCLC, achieved partial response to erlotinib after progression on first-line chemoimmunotherapy. High baseline phosphorylated EGFR values and reduced EGFR activation following erlotinib were observed in BRAF class 3-mutated and EGFR-mutated cell lines, but not in BRAF class 1-mutated, BRAF class 2-mutated, or KRAS-mutated lines. Erlotinib inhibited 2-dimensional growth in BRAF class 3-mutated cell lines (IC50 6.33 and 7.11 µM) and in the BRAF class 2-mutated cell line (IC50 5.51 µM), albeit at higher concentrations than in EGFR-mutated lines, whereas it showed no effect on BRAF class 1-mutated (IC50, >25 µM) or KRAS-mutated (IC50, >25 µM) lines. These findings were corroborated by 3-dimensional and sphere formation assays. In the Cancer Cell Line Encyclopedia, BRAF class 3-mutated NSCLC cell lines showed greater sensitivity to EGFR-TKIs compared with BRAF class 2-mutated and KRAS-mutated lines. BRAF class 3 mutations in NSCLC may identify a novel targetable population sensitive to EGFR-TKIs.

Exploration of the key active ingredients and mechanisms of Sparganii Rhizoma-Curcumae Rhizoma compatible formulation against human colorectal cancer through network pharmacology and in vitro experiments

IntroductionSparganii Rhizoma-Curcumae Rhizoma (SR-CR) formulation may offer an effective treatment for human colorectal cancer (CRC). However, the active ingredients and underlying mechanisms of this herbal formulation remain unclear. MethodsThis study integrates network pharmacology, molecular docking and experimental verification to identify key active ingredients and elucidate the mechanisms of SR-CR in CRC treatment. ResultsTwenty-three active components of SR-CR were identified using the TCMSP, UniProt and Gene Cards databases. These components were associated with 178 targets, of which 118 are directly related to CRC. Protein-protein interaction (PPI) network analysis identified protein kinase B (AKT) 1, epidermal growth factor receptor (EGFR), SRC, Bcl2 and CASP3 as core anti-CRC targets. Gene Ontology (GO) and KEGG pathway analyses were performed on these 178 intersecting targets, and the results showed that these targets are involved in EGFR tyrosine kinase inhibitor resistance and AGE-RAGE signaling pathway in diabetic complications. At the same time, five compounds, including bisdemethoxycurcumin, formononetin, β-sitosterol, stigmasterol and hederagenin, were selected based on the target number of effective components and tested for cytotoxicity against human CRC cell lines HT-29, HCT-8 and HCT-116 in vitro. The results showed that bisdemethoxycurcumin exhibited significant anti-proliferative activity against HCT-116 cells. Molecular docking results indicated that bisdemethoxycurcumin effectively binds with AKT, EGFR, Bcl-2 and CASP3. Further pharmacological experiments demonstrated that bisdemethoxycurcumin inhibits HCT-116 cell proliferation and migration via inhibiting EGFR-AKT pathway, and induces apoptosis by up-regulating Bcl-2 expression. DiscussionBased on our study, inhibiting the EGFR-AKT pathway and upregulating Bcl2 may be one of the mechanisms by which SR-CR inhibits the growth of CRC. The main active ingredients of SR-CR include bisdemethoxycurcumin, formononetin, β-sitosterol, stigmasterol and hederagenin, which may exert anti-colon cancer activity by targeting the regulation of AKT, EGFR, Bcl-2 and CASP3. However, we need more in vitro and in vivo evidence to confirm this conclusion. This study lays the foundation for further research on the pharmacological mechanism of SR-CR in the treatment of CRC.

Almonertinib and alflutinib show novel inhibition on rare EGFR S768I mutant cells.

EGFR classical mutations respond well to EGFR tyrosine kinase inhibitors. However, it is uncertain whether currently available EGFR-TKIs are effective against rare EGFR mutations and compound mutations. Herein, the effectiveness of almonertinib and alflutinib, the third-generation tyrosine kinase inhibitors developed in China, on rare EGFR S768I mutations and compound mutations is identified. In this study, using CRISPR method, four EGFR S768I mutation cell lines were constructed, and the sensitivity of EGFR to almonertinib and alflutinib was tested, with positive controls being the 1st (gefitinib), 2nd (afatinib), and 3rd (osimertinib) generation drugs. The present results indicate that almonertinib and alflutinib can effectively inhibit cell viability and proliferation in rare EGFR S768I mutations through the ERK or AKT pathways in a time-dependent manner, by blocking the cell cycle and inhibiting apoptosis. These findings suggest that almonertinib and alflutinib may be potential therapeutic options for non-small cell lung cancer patients with the EGFR S768I mutation.

The changing treatment landscape of EGFR-mutant non-small-cell lung cancer.

The discovery of the association between EGFR mutations and the efficacy of EGFR tyrosine-kinase inhibitors (TKIs) has revolutionized the treatment paradigm for patients with non-small-cell lung cancer (NSCLC). Currently, third-generation EGFR TKIs, which are often characterized by potent central nervous system penetrance, are the standard-of-care first-line treatment for advanced-stage EGFR-mutant NSCLC. Rational combinations of third-generation EGFR TKIs with anti-angiogenic drugs, chemotherapy, the EGFR-MET bispecific antibody amivantamab or local tumour ablation are being investigated as strategies to delay drug resistance and increase clinical benefit. Furthermore, EGFR TKIs are being evaluated in patients with early stage or locally advanced EGFR-mutant NSCLC, with the ambitious aim of achieving cancer cure. Despite the inevitable challenge of acquired resistance, emerging treatments such as new TKIs, antibody-drug conjugates, new immunotherapeutic approaches and targeted protein degraders have shown considerable promise in patients with progression of EGFR-mutant NSCLC on or after treatment with EGFR TKIs. In this Review, we describe the current first-line treatment options for EGFR-mutant NSCLC, provide an overview of the mechanisms of acquired resistance to third-generation EGFR TKIs and explore novel promising treatment strategies. We also highlight potential avenues for future research that are aimed at improving the survival outcomes of patients with this disease.

CCDC34 maintains stemness phenotype through β-catenin-mediated autophagy and promotes EGFR-TKI resistance in lung adenocarcinoma.

Despite recent advances in treatment strategy, lung cancer remains the leading cause of cancer-related mortality worldwide, and it is a serious threat to human health. Lung adenocarcinoma (LUAD) is the most common histological type of lung cancer, and approximately 40-50% of patients with LUAD in Asian populations have epidermal growth factor receptor (EGFR) mutations. The use of EGFR tyrosine kinase inhibitors (EGFR-TKIs) has revolutionarily improved the prognosis of patients with EGFR-mutated LUAD. However, acquired drug resistance is the main cause of treatment failure. Therefore, new therapeutic strategies are necessary to address the resistance to EGFR-TKIs in patients with LUAD. Cancer stemness-related factors lead to multiple-drug resistance in cancer treatment, including EGFR-TKI resistance. Coiled-coil domain-containing 34 (CCDC34) serves as an oncogene in several types of cancer. However, the role and molecular mechanism of CCDC34 in the malignant progression of LUAD have not been reported to date. In the present study, we found that CCDC34 may be associated with LUAD stemness through weighted gene co-expression network analysis (WGCNA). Furthermore, we demonstrated that CCDC34 promoted LUAD stemness properties through β-catenin-mediated regulation of ATG5-induced autophagy, which was conducive to acquired EGFR-TKI resistance in LUAD in vitro and in vivo. Knockdown CCDC34 can synergistically inhibit tumor growth when combined with EGFR-TKIs. This study reveals a positive association between CCDC34 and the stemness phenotype of LUAD, providing new insights into overcoming EGFR-TKI resistance in LUAD by inhibiting CCDC34 expression.

Prognostic impact of PD-L1 expression in surgically resected EGFR-mutant lung adenocarcinoma: A real-world database study in Japan (CReGYT-01 EGFR study).

The expression of programmed cell death-ligand 1 (PD-L1) and mutation in epidermal growth factor receptor (EGFR) are biomarkers used for perioperative treatment of lung adenocarcinoma. However, the clinical significance of PD-L1 expression in surgically resected EGFR-mutant lung adenocarcinoma remains unclear. We conducted a real-world database of patients with surgically resected lung adenocarcinoma from 2015 to 2018 was constructed across 21 centers in Japan. The association among PD-L1 expression, EGFR mutations, and prognosis was evaluated. Among 847 patients, PD-L1 expression was negative (tumor proportion score [TPS] < 1%) in 429 (51%), weakly positive (TPS = 1%-49%) in 275 (32%), and strongly positive (TPS ≥50%) in 143 (17%) patients. EGFR mutations were detected in 331 (39%) patients. PD-L1 expression was associated with poor recurrence-free survival (RFS) (p < .001) in both EGFR-mutant and wild-type patients. However, in EGFR-mutant patients, PD-L1 expression was not associated with overall survival (OS) (p = .506). Multivariable analysis confirmed an association between PD-L1 expression and RFS but not OS. Furthermore, in EGFR-mutant patients treated with EGFR-tyrosine kinase inhibitor (EGFR-TKI) treatment post-relapse, PD-L1 expression was not associated with overall response rate (p = .714), disease control rate (p = .554), or progression-free survival (p = .660). In conclusion, PD-L1 expression predicted poor RFS-independent EGFR status but did not show any association with OS in EGFR-mutant patients. The efficacy of post-relapse EGFR-TKI treatment was independent of PD-L1 expression. The significance of PD-L1 expression in perioperative EGFR-TKI therapy should be evaluated.

Exosomes derived from IFNγ-stimulated mesenchymal stem cells protect photoreceptors in RCS rats by restoring immune homeostasis through tsRNAs

BackgroundRetinitis pigmentosa is a neurodegenerative disease with major pathologies of photoreceptor apoptosis and immune imbalance. Mesenchymal stem cells (MSCs) have been approved for clinical application for treating various immune-related or neurodegenerative diseases. The objective of this research was to investigate the mechanisms underlying the safeguarding effects of MSC-derived exosomes in a retinal degenerative disease model.MethodsInterferon gamma-stimulated exosomes (IFNγ-Exos) secreted from MSCs were isolated, purified, and injected into the vitreous body of RCS rats on postnatal day (P) 21. Morphological and functional changes in the retina were examined at P28, P35, P42, and P49 in Royal College of Surgeons (RCS) rats. The mechanism was explored using high-throughput sequencing technology and confirmed in vitro.ResultsTreatment with IFNγ-Exo produced better protective effects on photoreceptors and improved visual function in RCS rats. IFNγ-Exo significantly suppressed the activated microglia and inhibited the inflammatory responses in the retina of RCS rats, which was also confirmed in the lipopolysaccharide-activated microglia cell line BV2. Furthermore, through tRNA-derived small RNA (tsRNA) sequencing, we found that IFNγ-Exos from MSCs contained higher levels of Other-1_17-tRNA-Phe-GAA-1-M3, Other-6_23-tRNA-Lys-TTT-3, and TRF-57:75-GLN-CGG-2-m2 than native exosomes, which mainly regulated inflammatory and immune-related pathways, including the mTOR signaling pathway and EGFR tyrosine kinase inhibitor resistance.ConclusionsIFNγ stimulation enhanced the neuroprotective effects of MSC-derived exosomes on photoreceptors of the degenerative retina, which may be mediated by immune regulatory tsRNAs acting on microglia. In conclusion, IFNγ-Exo is a promising nanotherapeutic agent for the treatment of retinitis pigmentosa.Graphical

Pyrrolo[2,3-D]Pyrimidines as EGFR and VEGFR Kinase Inhibitors: A Comprehensive SAR Review.

Tyrosine kinases are implicated in a wide array of cellular physiological processes, including cell signaling. The discovery of the BCR-ABL tyrosine kinase inhibitor imatinib and its FDA approval in 2001 paved the way for the development of small molecule chemical entities of diverse structural backgrounds as tyrosine kinase inhibitors for the treatment of various ailments. Two of the most prominent tyrosine kinases as drug targets are the epidermal growth factor receptor (EGFR) and the vascular endothelial growth factor receptor (VEGFR), as evidenced by the clinical success of their many inhibitors in the drug market. Among several other physiological roles, EGFR regulates epithelial tissue development and homeostasis, while VEGFR regulates tumor-induced angiogenesis. The pyrrolo[2,3-d]pyrimidine nucleus represents a deaza-isostere of adenine, the nitrogenous base of ATP. The recent introduction of many pyrrolo[2,3-d]pyrimidines to the drug market as tyrosine kinase inhibitors makes them a hot topic in the medicinal chemistry research area at the present time. This review article comprehensively sheds light on the structure-activity relationship (SAR) of pyrrolo[2,3-d]pyrimidines as EGFR and VEGFR tyrosine kinase inhibitors, aiming to provide help medicinal chemists in the design of future pyrrolopyrimidine kinase inhibitors.