Overview of the multifaceted resistances toward EGFR-TKIs and new chemotherapeutic strategies in non-small cell lung cancer

Rational design and synthesis of 2,4-dichloro-6-methyl pyrimidine derivatives as potential selective EGFRT790M/L858R inhibitors for the treatment of non-small cell lung cancer

Many patients with non-small cell lung cancer (NSCLC) initially benefit from epidermal growth factor receptor (EGFR) targeted therapy. Unfortunately, varying degrees of resistance or side effects eventually develop. Overcoming and preventing the resistance and side effects of EGFR inhibitors has become a hot topic of research today. Based on the previous studies on AZD-9291, we designed and synthesized two series of 2,4-dichloro-6-methylpyrimidine derivatives, 19 compounds in total, as potential inhibitors of the EGFR kinase. The most promising compound, L-18, showed better inhibitory activity (81.9%) and selectivity against EGFRT790M/L858R kinase. In addition, L-18 showed strong antiproliferative activity against H1975 cells with an IC50 value of 0.65 ± 0.06 μM and no toxicity to normal cells (LO-2). L-18 was able to dose-dependently induce the apoptosis of H1975 cells and produced a cell-cycle-blocking effect, and it can also dose-dependently inhibit the migration and invasion of H1975 cells. L-18 also showed in vivo anticancer efficacy in H1975 cells xenograft mice. We also performed a series of in vivo and in vitro toxicological evaluations of compound L-18, which did not cause obvious injury in mice during administration. These results suggest that L-18 may be a promising drug candidate that warrants further investigation.

Single cell lineage tracing reveals clonal dynamics of anti-EGFR therapy resistance in triple negative breast cancer

BACKGROUND

Most primary Triple Negative Breast Cancers (TNBCs) show amplification of the Epidermal Growth Factor Receptor (EGFR) gene, leading to increased protein expression. However, unlike other EGFR-driven cancers, targeting this receptor in TNBC yields inconsistent therapeutic responses.

METHODS

To elucidate the underlying mechanisms of this variability, we employ cellular barcoding and single-cell transcriptomics to reconstruct the subclonal dynamics of EGFR-amplified TNBC cells in response to afatinib, a tyrosine kinase inhibitor (TKI) that irreversibly inhibits EGFR.

RESULTS

Integrated lineage tracing analysis revealed a rare pre-existing subpopulation of cells with distinct biological signature, including elevated expression levels of Insulin-Like Growth Factor Binding Protein 2 (IGFBP2). We show that IGFBP2 overexpression is sufficient to render TNBC cells tolerant to afatinib treatment by activating the compensatory insulin-like growth factor I receptor (IGF1-R) signalling pathway. Finally, based on reconstructed mechanisms of resistance, we employ deep learning techniques to predict the afatinib sensitivity of TNBC cells.

CONCLUSIONS

Our strategy proved effective in reconstructing the complex signalling network driving EGFR-targeted therapy resistance, offering new insights for the development of individualized treatment strategies in TNBC.

PRKCSH serves as a potential immunological and prognostic biomarker in pan-cancer

Protein kinase C substrate 80K-H (PRKCSH) plays a crucial role in the protein N-terminal glycosylation process, with emerging evidence implicating its involvement in tumorigenesis. To comprehensively assess PRKCSH's significance across cancers, we conducted a pan-cancer analysis using data from The Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), and Cancer Cell Line Encyclopedia (CCLE). We assessed aberrant PRKCSH mRNA and protein expression, examined its prognostic implications, and identified correlations with clinical features, tumor mutational burden (TMB), microsatellite instability (MSI), and tumor immunity across cancer types. We explored PRKCSH gene alterations, DNA methylation, and their impact on patient prognosis. Gene Set Enrichment Analysis (GSEA) and single-cell analysis revealed potential biological roles. Additionally, we investigated drug susceptibility and conducted Connectivity Map (Cmap) analysis. Key findings revealed that PRKCSH exhibited overexpression in most tumors, with a significant association with poor overall survival (OS) in six cancer types. Notably, PRKCSH expression demonstrated variations across disease stages, primarily increasing in advanced stages among eleven tumor types. Moreover, PRKCSH exhibited significant correlations with TMB in five cancer categories, MSI in eight, and displayed associations with immune cell populations in pan-cancer analysis. Genetic variations in PRKCSH were identified across 26 tumor types, suggesting favorable disease-free survival. Furthermore, PRKCSH methylation displayed a significant negative correlation with its expression in 27 tumor types, with a marked decrease compared to normal tissues in ten tumors. Cmap predicted 24 potential therapeutic small molecules in over four cancer types. This study highlights that PRKCSH, as a potential oncogene, may be a promising prognostic marker and therapeutic target of immunotherapy for a range of malignancies.

New Directions for Advanced Targeting Strategies of EGFR Signaling in Cancer

Epidermal growth factor (EGF)-EGF receptor (EGFR) signaling studies paved the way for a basic understanding of growth factor and oncogene signaling pathways and the development of tyrosine kinase inhibitors (TKIs). Due to resistance mutations and the activation of alternative pathways when cancer cells escape TKIs, highly diverse cell populations form in recurrent tumors through mechanisms that have not yet been fully elucidated. In this review, we summarize recent advances in EGFR basic research on signaling networks and intracellular trafficking that may clarify the novel mechanisms of inhibitor resistance, discuss recent clinical developments in EGFR-targeted cancer therapy, and offer novel strategies for cancer drug development.

Epidermal growth factor receptor dual-target inhibitors as a novel therapy for cancer: A review

Overexpression of the epidermal growth factor receptor (EGFR) has been linked to several human cancers, including esophageal cancer, pancreatic cancer, anal cancer, breast cancer, and lung cancer, particularly non-small cell lung cancer (NSCLC). Therefore, EGFR has emerged as a critical target for treating solid tumors. Many 1st-, 2nd-, 3rd-, and 4th-generation EGFR single-target inhibitors with clinical efficacy have been designed and synthesized in recent years. Drug resistance caused by EGFR mutations has posed a significant challenge to the large-scale clinical application of EGFR single-target inhibitors and the discovery of novel EGFR inhibitors. Therapeutic methods for overcoming multipoint EGFR mutations are still needed in medicine. EGFR dual-target inhibitors are more promising than single-target inhibitors as they have a lower risk of drug resistance, higher efficacy, lower dosage, and fewer adverse events. EGFR dual-target inhibitors have been developed sequentially to date, providing new options for remission in patients with previously untreatable malignancies and laying the groundwork for a future generation of compounds. This paper introduces the EGFR family proteins and their synergistic effects with other anticancer targets, and provides a comprehensive review of the development of EGFR dual-target inhibitors in cancer, as well as the opportunities and challenges associated with those fields.

The potential therapeutic regimen for overcoming resistance to osimertinib due to rare mutations in NSCLC

The mechanisms of osimertinib resistance have not been well characterized. We conducted next-generation sequencing to recognize novel resistance mechanism and used cell line-derived xenograft (CDX) and patient-derived xenograft (PDX) models to evaluate the anti-proliferative effects of aspirin in vivo and in vitro. We observed that PIK3CG mutations led to acquired resistance to osimertinib in a patient and further confirmed that both PIK3CG and PIK3CA mutations caused osimertinib resistance. Mechanistically, the expression of PI3Kγ or PI3Kα was up-regulated after PIK3CG or PIK3CA lentivirus transfection, respectively, and which can be effectively suppressed by aspirin. Lastly, our results from in vivo studies indicate that aspirin can reverse osimertinib resistance caused by PIK3CG or PIK3CA mutations in both CDX and PDX models. Herein, we first confirmed that mutations in PIK3CG can lead to resistance to osimertinib, and the combined therapy may be a strategy to reverse PIK3CG/PIK3CA mutation-induced osimertinib resistance.

Long non-coding RNAs in non-small cell lung cancer: implications for EGFR-TKI resistance

Non-small cell lung cancer (NSCLC) is one of the most common types of malignant tumors as well as the leading cause of cancer-related deaths in the world. The application of epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) has dramatically improved the prognosis of NSCLC patients who harbor EGFR mutations. However, despite an excellent initial response, NSCLC inevitably becomes resistant to EGFR-TKIs, leading to irreversible disease progression. Hence, it is of great significance to shed light on the molecular mechanisms underlying the EGFR-TKI resistance in NSCLC. Long non-coding RNAs (lncRNAs) are critical gene modulators that are able to act as oncogenes or tumor suppressors that modulate tumorigenesis, invasion, and metastasis. Recently, extensive evidence demonstrates that lncRNAs also have a significant function in modulating EGFR-TKI resistance in NSCLC. In this review, we present a comprehensive summary of the lncRNAs involved in EGFR-TKI resistance in NSCLC and focus on their detailed mechanisms of action, including activation of alternative bypass signaling pathways, phenotypic transformation, intercellular communication in the tumor microenvironment, competing endogenous RNAs (ceRNAs) networks, and epigenetic modifications. In addition, we briefly discuss the limitations and the clinical implications of current lncRNAs research in this field.