Lung cancer is the malignancy with the highest incidence and mortality burden globally, ranking first in both morbidity and mortality among all types of malignant tumors. Pathologically, lung cancer is classified into non-small cell lung cancer (NSCLC) and small cell lung cancer, with NSCLC accounting for approximately 85% of cases. Due to the often subtle or nonspecific clinical manifestations in early-stage disease, many patients are diagnosed at a locally advanced or metastatic stage, where treatment options are limited and prognosis remains poor. Therefore, molecular targeted therapy focusing on driver genes has become a key strategy to improve the survival outcomes of patients with advanced NSCLC. The epidermal growth factor receptor (EGFR) is one of the most common driver genes in NSCLC. While EGFR mutations occur in approximately 12% of advanced NSCLC patients globally, the incidence rises to 55.9% in Chinese patients. Among EGFR mutations, P-loop and αC-helix compressing (PACC) mutations account for about 12.5%. Currently, EGFR tyrosine kinase inhibitors (TKIs) have become the first-line standard treatment for advanced NSCLC patients with classical EGFR mutations, with efficacy well-established through clinical studies and real-world evidence. However, with rapid advancements in NSCLC precision medicine and deeper exploration of the EGFR mutation spectrum, EGFR PACC mutations have emerged as a key clinical focus. The structural characteristics of these mutations lead to significant variability in responses to EGFR TKIs, leaving therapeutic options still limited, while detection challenges persist due to the sensitivity constraints of current testing technologies, driving increasing demand for improved diagnostic and treatment approaches. The current clinical evidence primarily stems from retrospective analyses and small-scale exploratory studies, while prospective, large-scale, high-level evidence-based medical research specifically targeting this mutation subtype remains notably insufficient. This evidence gap has consequently led to the absence of standardized guidelines or expert consensus regarding optimal treatment strategies for advanced NSCLC with EGFR PACC mutations. As a clinical consensus specifically addressing EGFR PACC-mutant NSCLC, this document provides a comprehensive framework encompassing the clinical rationale for EGFR PACC mutation testing, therapeutic strategies for advanced-stage disease, management of treatment-related adverse events, and follow-up protocols. The consensus underscores the pivotal role of EGFR PACC mutation detection in precision medicine implementation while offering evidence-based recommendations to guide personalized therapeutic decision-making. By establishing clear clinical pathways encompassing molecular testing, therapeutic intervention, and long-term monitoring for EGFR PACC-mutant NSCLC, this consensus aims to meaningfully improve patient survival outcomes while serving as a robust, evidence-based foundation for developing personalized clinical management approaches.
Humans ; Carcinoma, Non-Small-Cell Lung/pathology* ; ErbB Receptors/antagonists & inhibitors* ; Mutation ; Lung Neoplasms/pathology* ; Protein Kinase Inhibitors/therapeutic use* ; Molecular Targeted Therapy ; Consensus

Cancer multidrug resistance (MDR) impairs the therapeutic efficacy of various chemotherapeutics. Novel approaches, particularly the development of MDR reversal agents, are critically needed to address this challenge. This study demonstrates that tenacissoside I (TI), a compound isolated from Marsdenia tenacissima (Roxb.) Wight et Arn, traditionally used in clinical practice as an ethnic medicine for cancer treatment, exhibits significant MDR reversal effects in ABCB1-mediated MDR cancer cells. TI reversed the resistance of SW620/AD300 and KBV200 cells to doxorubicin (DOX) and paclitaxel (PAC) by downregulating ABCB1 expression and reducing ABCB1 drug transport function. Mechanistically, protein arginine methyltransferase 1 (PRMT1), whose expression correlates with poor prognosis and shows positive association with both ABCB1 and EGFR expressions in tumor tissues, was differentially expressed in TI-treated SW620/AD300 cells. SW620/AD300 and KBV200 cells exhibited elevated levels of EGFR asymmetric dimethylarginine (aDMA) and enhanced PRMT1-EGFR interaction compared to their parental cells. Moreover, TI-induced PRMT1 downregulation impaired PRMT1-mediated aDMA of EGFR, PRMT1-EGFR interaction, and EGFR downstream signaling in SW620/AD300 and KBV200 cells. These effects were significantly reversed by PRMT1 overexpression. Additionally, TI demonstrated resistance reversal to PAC in xenograft models without detectable toxicities. This study establishes TI's MDR reversal effect in ABCB1-mediated MDR human cancer cells through inhibition of PRMT1-mediated aDMA of EGFR, suggesting TI's potential as an MDR modulator for improving chemotherapy outcomes.
Humans ; Protein-Arginine N-Methyltransferases/antagonists & inhibitors* ; Drug Resistance, Neoplasm/drug effects* ; ErbB Receptors/genetics* ; Animals ; Cell Line, Tumor ; Drug Resistance, Multiple/drug effects* ; Methylation/drug effects* ; Saponins/administration & dosage* ; Mice ; Mice, Nude ; Mice, Inbred BALB C ; ATP Binding Cassette Transporter, Subfamily B/genetics* ; Doxorubicin/pharmacology* ; Paclitaxel/pharmacology* ; Female ; Repressor Proteins

With the rapid development of epidermal growth factor receptor (EGFR) gene testing of lung adenocarcinoma patients has been routinely carried out, EGFR mutations are also possible for some small samples of non-smoking female lung squamous cell carcinoma patients. This increases the opportunity for targeted therapy for this group of patients. However, drug resistance in patients with lung squamous cell carcinoma during targeted therapy is an important factor affecting subsequent treatment. There are multiple mechanisms of acquired drug resistance in targeted therapy, and the alteration of mesenchymal-epithelial transition factor (MET) signaling pathway is one of the common mechanisms of drug resistance. At present, some selective tyrosine kinase inhibitors (TKIs) of MET has been approved for non-small cell lung cancer with MET gene 14 exon skipping mutation, such as Glumetinib, Savolitinib, Tepotinib, Capmatinib, etc. Drugs that target secondary MET amplification are still in clinical trials. This paper retrospectively analyzed the clinical data of a female patient with EGFR-TKIs resistant secondary MET amplified squamous cell lung cancer, and reviewed relevant literature to explore how to optimize the treatment of lung squamous cell carcinoma patients with EGFR mutation, so as to provide clinical reference for the diagnosis and treatment of such patients.
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Female ; Humans ; Carcinoma, Squamous Cell/drug therapy* ; Drug Resistance, Neoplasm/genetics* ; ErbB Receptors/antagonists & inhibitors* ; Gene Amplification ; Lung Neoplasms/drug therapy* ; Protein Kinase Inhibitors/pharmacology* ; Proto-Oncogene Proteins c-met/genetics*

CUDC-101, an effective and multi-target inhibitor of epidermal growth factor receptor (EGFR), histone deacetylase (HDAC), and human epidermal growth factor receptor 2 (HER2), has been reported to inhibit many kinds of cancers, such as acute promyelocytic leukemia and non-Hodgkin's lymphoma. However, no studies have yet investigated whether CUDC-101 is effective against myeloma. Herein, we proved that CUDC-101 effectively inhibits the proliferation of multiple myeloma (MM) cell lines and induces cell apoptosis in a time- and dose-dependent manner. Moreover, CUDC-101 markedly blocked the signaling pathway of EGFR/phosphoinositide-3-kinase (PI3K) and HDAC, and regulated the cell cycle G2/M arrest. Moreover, we revealed through in vivo experiment that CUDC-101 is a potent anti-myeloma drug. Bortezomib is one of the important drugs in MM treatment, and we investigated whether CUDC-101 has a synergistic or additive effect with bortezomib. The results showed that this drug combination had a synergistic anti-myeloma effect by inducing G2/M phase blockade. Collectively, our findings revealed that CUDC-101 could act on its own or in conjunction with bortezomib, which provides insights into exploring new strategies for MM treatment.
Humans ; Antineoplastic Agents/therapeutic use* ; Apoptosis ; Bortezomib/pharmacology* ; Cell Line, Tumor ; Cell Proliferation ; ErbB Receptors/antagonists & inhibitors* ; G2 Phase Cell Cycle Checkpoints ; Histone Deacetylase Inhibitors/pharmacology* ; Histone Deacetylases/metabolism* ; M Cells ; Multiple Myeloma/drug therapy*

BACKGROUND: Long noncoding RNAs (lncRNAs) play pivotal roles in various malignant tumors. Epidermal growth factor receptor (EGFR) signaling is associated with the pathogenesis of cutaneous squamous cell carcinoma (cSCC). This study aimed to explore the role of LINC00520 in the development of cSCC via EGFR and phosphoinositide 3-kinase-protein kinase B (PI3K/Akt) signaling pathways. METHODS: A microarray analysis was applied to screen differentially expressed lncRNAs in cSCC samples. The A431 cSCC cell line was transfected and assigned different groups. The expression patterns of LINC00520, EGFR, and intermediates in the PI3K/Akt pathway were characterized using reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blotting analysis. Cell proliferation, migration, and invasion were detected using the MTT assay, scratch test, and Transwell assay, respectively. Cell-based experiments and a tumorigenicity assay were conducted to assess the effect of LINC00520 on cSCC progression. This study was ended in September 2017. Comparisons between two groups were analyzed with t-test and comparisons among multiple groups were analyzed using one-way analysis of variance. The nonparametric Wilcoxon rank sum test was used to analyze skewed data. The enumerated data were analyzed using the chi-square test or Fisher exact test. RESULTS: Data from chip GSE66359 revealed depletion of LINC00520 in cSCC. Cells transfected with LINC00520 vector and LINC00520 vector + si-EGFR showed elevated LINC00520 level but decreased levels of the EGFR, PI3K, AKT, VEGF, MMP-2 and MMP-9 mRNAs and proteins, and inhibition of the growth, migration and adhesion of cSCC cells, while the si-LINC00520 group showed opposite trends (all P < 0.05). Compared with the LINC00520 vector group, the LINC00520 vector + si-EGFR group showed decreased levels of the EGFR, PI3K, AKT, VEGF, MMP-2 and MMP-9 mRNAs and proteins, and inhibition of the growth, migration and adhesion of cSCC cells, while the LINC00520 vector + EGFR vector group showed opposite results (all P < 0.05). CONCLUSION Based on our results, LINC00520-targeted EGFR inhibition might result in the inactivation of the PI3K/Akt pathway, thus inhibiting cSCC development.
Animals ; Carcinoma, Squamous Cell ; pathology ; prevention & control ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Disease Progression ; ErbB Receptors ; antagonists & inhibitors ; Female ; Humans ; Lymphatic Metastasis ; Mice ; Neoplasm Invasiveness ; Phosphatidylinositol 3-Kinases ; physiology ; Proto-Oncogene Proteins c-akt ; physiology ; RNA, Long Noncoding ; physiology ; Signal Transduction ; physiology ; Skin Neoplasms ; pathology ; prevention & control

With the development of sequencing technology, the detection rate of de novo T790M mutation is increasing. The emergence of the third generation of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) provide treatment opportunities. Secondary T790M mutation is often emphasized in clinic, but de novo T790M mutation is neglected. This review found that the incidence of de novo T790M mutation fluctuated greatly, which was mainly affected by sequencing techniques. The de novo T790M mutation is mainly low in mutation abundance, easy to combine with other gene changes, a poor predictor and prognostic factor and the efficacy of the first and second generation EGFR-TKIs is limited. The therapeutic value of osimertinib needs to be studied.
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Carcinoma, Non-Small-Cell Lung ; diagnosis ; drug therapy ; enzymology ; genetics ; ErbB Receptors ; antagonists & inhibitors ; genetics ; Humans ; Lung Neoplasms ; diagnosis ; drug therapy ; enzymology ; genetics ; Mutation ; Prognosis ; Protein Kinase Inhibitors ; pharmacology ; therapeutic use

BACKGROUND: Advanced epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma had a high overall incidence of brain metastasis during the full course, and local brain radiotherapy combined with systemic targeted therapy may be a better strategy. This study aimed to identify the prognostic factors of EGFR-mutant brain-metastatic lung adenocarcinoma patients who received EGFR-tyrosine kinase inhibitors (EGFR-TKIs) in combination with gamma knife radiosurgery. METHODS: Retrospective analysis of EGFR-mutant lung adenocarcinoma patients with brain metastases which developed at initial diagnosis or during EGFR-TKIs treatment period were performed. Intracranial progression free survival (PFS) was statistically analyzed between different subgroups to find out the prognostic factors including gender, age, smoking history, extracranial metastasis, EGFR mutation type, size and number of intracranial lesions, carcino-embryonic antigen (CEA) level, lung-molGPA score and so on. RESULTS: A total of 74 EGFR-mutant brain-metastatic lung adenocarcinoma patients were enrolled in this study, with median intracranial PFS of 14.7 months. One-year intracranial-progression-free rate was 58.5%, and two-year rate was 22.2%. Univariate survival analysis showed that patients with lower CEA level at initial diagnosis (<10 ng/L)(16.9 months vs 12.6 months, P=0.012) and smaller intracranial lesions (<2 cm)(15.4 months vs 10.8 months, P=0.021) and higher lung-molGPA score (>3)(15 months vs 12.6 months, P=0.041) were prone to have a superior intracranial PFS. Multivariate analysis showed that CEA≥10 ng/mL and intracranial lesion≥2 cm were the independent risk factors of intracranial PFS. CONCLUSIONS EGFR-TKIs in combination with gamma knife radiosurgery was an efficient treatment option to control the cranial tumor lesion. CEA≥10 μg/L at initial diagnosis and intracranial lesion≥2 cm were the risk factors of EGFR-mutant brain-metastatic lung adenocarcinoma patients receiving EGFR-TKIs in combination with gamma knife radiosurgery.
Adenocarcinoma of Lung ; drug therapy ; pathology ; radiotherapy ; therapy ; Adult ; Aged ; Brain Neoplasms ; secondary ; Combined Modality Therapy ; ErbB Receptors ; antagonists & inhibitors ; genetics ; Female ; Humans ; Male ; Middle Aged ; Mutation ; Prognosis ; Protein Kinase Inhibitors ; pharmacology ; therapeutic use ; Radiosurgery ; Retrospective Studies

BACKGROUND: Adenocarcinoma is the most common type of lung cancer. It has been clinically evaluated that therapiestargeting against the epidermal growth factor receptor (EGFR) as the clinical standard first-line treatment. The response and outcome of EGFR-tyrosine kinase inhibitors (TKIs) in patients harboring common mutations in EGFR kinase domain (deletion in exon19 and L858R in exon 21) has been well demonstrated, but not in rare or complex mutations. METHODS: A total of 150 patients that harbored rare or complex mutations in EGFR diagnosed by histopathology were included in this retrospective study. The clinical-pathological characteristics of all 150 patients as well as the response and progression-free survival (PFS) in 48 patients that received EGFR-TKIs in first/second/third line treatments weredescribed and analyzed. RESULTS: Patients were divided into four groups based on the mutation types: single G719X point mutation in exon 18 (n=46, 30.7%), single L861Q point mutation in exon 21 (n=45, 30.0%), other single rare mutation (n=14, 9.3%) and complex mutations (n=45, 30.0%). The result indicated thatthere was no correlation of EGFR mutation typeswith other parameters such as gender, age, clinical stage, pathology and smoking history. For the 48 patients that received EGFR-TKIs treatment, there were no significant differencesamong 4 groups in terms of objective response rate (ORR) and disease control rate (DCR) (54.5% vs 30.0% vs 0.0% vs 35.7%, χ²=3.200, P=0.34; 90.9% vs 85.0% vs 66.7% vs 92.9%, χ²=2.162, P=0.59). The median progress-free survival (mPFS) was 11.0 months (95%CI: 4.4-17.6), and in each group of different EGFR mutation types are 15.8 months (95%CI: 9.5-22.2), 8.0 months (95%CI: 5.1-11.0), 4.9 months (95%CI: 1.4-8.4) and 23.1 months (95%CI: 15.8-30.4)(χ²=7.876, P=0.049). CONCLUSIONS The efficiency of targeting EGFR-TKIs on different types of rare or complex mutations was heterogeneous. The PFS may be better in patients that harbored complex mutations than those with single rare mutations. Further studies with larger sample size are necessary. Moreover, to discover novel therapeutic targets and develop new drugs are imminentfor those patientswith no response to the existing treatments.
Carcinoma, Non-Small-Cell Lung ; drug therapy ; genetics ; Disease-Free Survival ; ErbB Receptors ; antagonists & inhibitors ; genetics ; Exons ; genetics ; Female ; Humans ; Lung Neoplasms ; drug therapy ; genetics ; Male ; Middle Aged ; Mutation ; Protein Kinase Inhibitors ; pharmacology ; therapeutic use ; Retrospective Studies ; Treatment Outcome

BACKGROUND: Lung cancer is one of the common malignant tumors that impair human health. With the development of epigenetics, the researchers found that enhancer of Zeste homolog 2 (EZH2) is highly expressed in lung cancer tissue and its expression is closely related to the prognosis. EZH2 inhibitor can also enhance the sensitivity of tumor cells to a variety of anti-tumor drugs. The purpose of this study is to investigate the effect of combination of EZH2 inhibitor and gefitinib on the proliferation, apoptosis and migration of Gefitinib-resistant lung cancer cells. METHODS: PC9 and PC9/AB2 cells were used for this study. CCK-8 and EdU experiment were used to detect combined treatment on cell viability and proliferation activity; Wound healing assay and Transwell chamber experiment were used to determine the effects of combination therapy on cell migration ability; Flow cytometry was used to detect the effect of combination therapy on EZH2 and apoptosis; Western blot was used to observe the effect of combination therapy on epidermal growth factor receptor (EGFR) signaling pathway-related proteins expression. RESULTS: In gefitinib-resistant cell line PC9/AB2, gefitinib combined with EZH2 inhibitor GSK343 can significantly inhibit cell viability, reduce cell migration and increase cell apoptosis. At the same time, combination therapy can significantly inhibit the expression of EZH2 and phosphorylation EGFR proteins. CONCLUSIONS The combination of EZH2 inhibitor GSK343 and gefitinib sensitize PC9/AB2 cell to gefitinib response. This study also suggests that synergistic therapy plays a role in the reversal of EGFR-tyrosine kinase inhibitor (EGFR-TKIs) resistance in lung cancer.
Antineoplastic Agents ; pharmacology ; Cell Line, Tumor ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Drug Resistance, Neoplasm ; drug effects ; Drug Synergism ; Enhancer of Zeste Homolog 2 Protein ; antagonists & inhibitors ; ErbB Receptors ; antagonists & inhibitors ; Gefitinib ; pharmacology ; Humans ; Lung Neoplasms ; pathology ; Protein Kinase Inhibitors ; pharmacology

ErbB receptor tyrosine kinase inhibitors (EGFR-TKI), gefitinib, erlotinib, icotinib and aftinib, which are approved as a frontline treatment for patients with non-small cell lung cancer (NSCLC) who have tumors harboring EGFR mutations in China. And osimertinib was approved in second line setting for patients with EGFRT 790M-positive NSCLC. Rash, paronychia, diarrhea, stomatitis, liver dysfunction and (interstitial lung disease, ILD) are frequently observed in patients treated with EGFR-TKI. Chinese Society of Lung Cancer, Chinese Anti-Cancer Association, organized Chinese experts to develop the Chinese expert consensus on EGFR-TKI adverse event (AE) management based on domestic diagnosis and treatment of ADR and also incorporating international updated theory and recommendations.
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Antineoplastic Agents ; adverse effects ; therapeutic use ; Carcinoma, Non-Small-Cell Lung ; drug therapy ; enzymology ; genetics ; China ; Diarrhea ; etiology ; ErbB Receptors ; antagonists & inhibitors ; genetics ; metabolism ; Humans ; Liver Diseases ; etiology ; Lung Diseases ; etiology ; Lung Neoplasms ; drug therapy ; enzymology ; genetics ; Protein Kinase Inhibitors ; adverse effects ; therapeutic use ; Stomatitis ; etiology