Genomic characterisation of de novo EGFR copy number gain and its impact on the efficacy of first-line EGFR-tyrosine kinase inhibitors for EGFR mutated non-small cell lung cancer

Implications of EGFR expression on EGFR signaling dependency and adaptive immunity against EGFR-mutated lung adenocarcinoma

BACKGROUND

In EGFR-mutated lung adenocarcinoma (EGFRm LUAD), EGFR mutations do not necessarily result in increased EGFR expression (EGFR-exp), which differs among patients. However, the factors influencing EGFR-exp and the impact of EGFR-exp on tumor characteristics in patients with EGFRm LUAD remain unclear.

PATIENTS AND METHODS

Whole-exome and RNA sequencing were performed for patients with early- and advanced-stage EGFRm LUAD. The patients were classified into low or high EGFR-exp groups based on the median transcripts per million. We retrospectively examined the association between EGFR-exp, genomic characteristics, downstream EGFR signaling activity, tumor microenvironment (TME) status, and clinical outcomes.

RESULTS

This study included 450 and 45 patients in the early- and advanced-stage cohorts, respectively. In both cohorts, the EGFR-exp low group exhibited a lower incidence of TP53 co-mutations and EGFR amplification and a higher incidence of EGFR subclonal mutations than the EGFR-exp high group. Furthermore, downstream EGFR signaling pathways, such as the MAPK signaling, were less activated in the EGFR-exp low group. However, this group showed significantly enriched adaptive immune response pathways (Q < 0.0001) and an immune-inflamed TME. Additionally, a low EGFR-exp was a significantly favorable factor for postoperative relapse (odds ratio [OR], 0.6; P = 0.04). However, in the advanced-stage cohort, a low EGFR-exp was a significant risk factor for non-responders to osimertinib (OR, 17.5; P = 0.03).

CONCLUSIONS

In EGFRm LUAD, significant associations were observed between EGFR-exp levels and both EGFR signaling pathways and adaptive immune status, which in turn influence clinical outcomes. This large-scale multi-omics analysis highlights the heterogeneity among patients with EGFRm LUAD and emphasizes the need to assess EGFR-exp levels alongside mutation status for optimal treatment strategies in EGFRm LUAD.

Epidemiological characteristics and therapeutic advances of EGFR exon 20 insertion mutations in non-small cell lung cancer

The third most prevalent type of epidermal growth factor receptor (EGFR) mutation, EGFR exon 20 insertions (EGFRex20ins), involves 2%-12% of all cases of EGFR-positive non-small cell lung cancer (NSCLC). Approximately 90% of the mutations occur within the loop structure region, and the most frequently reported subtypes are A767_V769dup and S768_D770dup, which together account for almost 50% of instances. Apart from the unique subtype of A763_Y764insFQEA, NSCLCs with EGFRex20ins are resistant to approved EGFR tyrosine kinase inhibitors (TKIs) and are also insensitive to chemotherapy or immunotherapy. A new modality of treatment for NSCLC patients with EGFRx20ins has been established with the approval of mobocertinib and amivantamab. There are also numerous novel targeted treatments for NSCLC with EGFRex20ins in development, which are anticipated to improve this patient population's survival even further. This review provides a reference for the clinical management of these patients by summarizing the most recent epidemiological, and clinicopathological characteristics, diagnostic techniques, and therapeutic advances of EGFRex20ins in NSCLC.

Novel PPFIA1-ALK, ALK-C2orf91(intergenic) double-fusion responded well to alectinib in an advanced lung adenocarcinoma patient: a case report

Non-small cell lung cancers (NSCLCs) with anaplastic lymphoma kinase (ALK)-rearrangement have favorable responses to ALK inhibitors. However, ALK fusion mutations harbored approximately 90 distinct fusion partners. Patients with different ALK fusions might respond distinctly to different-generation ALK inhibitors. In this case report, we identified a novel non-reciprocal ALK fusion, ALK-C2orf91(intergenic) (A19: intergenic) and PPFIA1-ALK (P2:A20), by next-generation DNA sequencing in an advanced lung adenocarcinoma patient. After 2 months of alectinib, the targeted lung lesion regressed significantly, and evaluation of therapeutic efficiency indicated partial response. To date, the patient had achieved 12 months of progression-free survival from alectinib treatment. Our study extended the spectrum of ALK fusion partners in ALK-positive NSCLC, and we reported a new ALK fusion, PPFIA1-ALK and ALK-C2orf91(intergenic), and its sensitivity to alectinib firstly in lung cancer. We believe that this case report has an important clinical reference.

Raddeanin A Improves the Therapeutic Effect of Osimertinib in NSCLC by Accelerating ROS/NLRP3-mediated Pyroptosis

BACKGROUND

Osimertinib (Osm) is the preferred treatment for non-small cell lung cancer (NSCLC) patients with the epidermal growth factor receptor (EGFR) T790M mutation. Nevertheless, the resistance of NSCLC cells to Osm will eventually develop, which remains the biggest obstacle to treating such diseases. Raddeanin A (RA) exhibits a potent anti-tumor effect on various types of cancer cells. In this study, we aimed to investigate whether RA suppresses NSCLC growth and increases the therapeutic effect of Osm.

METHODS

The effects of RA on inhibiting NSCLC cell viability and proliferation were tested using cell counting kit 8 (CCK-8) and EdU assay. The roles of RA in improving the anti-tumor effect of Osm were tested with CCK-8 and colony formation assays. The roles of RA in regulating reactive oxygen species (ROS)/NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3)-mediated pyroptosis were assessed using quantitative real- time PCR (qRT-PCR) and western blotting analysis.

RESULTS

RA treatment decreased A549 and H1975 cell viability in a dose- and time-dependent way. RA inhibited NSCLC cell proliferation and tumor growth in vivo. Mechanistically, RA induced ROS overgeneration and resulted in subsequent NLRP3-mediated pyroptosis. In particular, combination treatment with Osm and RA reduced cell viability and clonogenic growth capacity more efficiently than Osm mono treatment in A549 and H1975 cells. Combination treatment also promoted NLRP3-mediated pyroptosis more efficiently than Osm mono treatment.

CONCLUSION

RA inhibited the NSCLC growth and increased the anti-tumor role of Osm in NSCLC by facilitating ROS/NLRP3-mediated pyroptosis. These results suggested that combination therapy with RA and Osm might be an effective strategy to treat Osm-resistant NSCLC.