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

TTC7A-ALK, a novel ALK fusion variant identified in a patient with metastatic lung adenocarcinoma, exhibits excellent response to crizotinib

Non-small cell lung cancer (NSCLC) remains a leading cause of cancer-related mortality worldwide. ALK gene rearrangement has been identified in 3 % to 5 % of the patients with NSCLC. Thanks to the advancements in second-generation sequencing technology, an increasing number of novel fusion partners have been identified. In our research, we discovered a rare ALK fusion, TTC7A-ALK, in a patient with advanced lung adenocarcinoma using targeted next-generation sequencing (NGS). After being diagnosed with advanced lung adenocarcinoma with TTC7A-ALK fusion, the patient received crizotinib treatment and achieved a progression-free survival of 29 months. Additonanlly, we conducted further functional analyses on this fusion protein to assess its oncogenic potential. Similar to EML4-ALK, the TTC7A-ALK fusion protein can promote the growth of Ba/F3 cells under IL-3-independent conditions in vitro. In vivo studies demonstrate that the TTC7A-ALK fusion protein could enhance the tumorigenesis of NIH3T3 cells in nude mice, which can be suppressed by crizotinib. Mechanistic studies indicated that the ectopic expression of TTC7A-ALK in 293T cells led to the hyperactivation of downstream MAPK and PI3K/Akt pathways, which can be inhibited by crizotinib. Furthermore, upon tumor progression, the patient transitioned to alectinib, which provided rapid symptom relief and controlled the majority of lesions. Conclusionly, we identified and validated TTC7A-ALK as a oncogenic fusion in NSCLC. The patient demonstrated a significant clinical benefit from sequential treatment with crizotinib and alectinib, highlighting TTC7A-ALK as a novel therapeutic target for ALK inhibitors. These findings extend the spectrum of actionable ALK fusions and promote the inclusion of rare fusion detection in clinical diagnostic processes and treatment strategies.

Identifying potential therapeutic targets in lung adenocarcinoma: a multi-omics approach integrating bulk and single-cell RNA sequencing with Mendelian randomization

Our research aimed to identify new therapeutic targets for Lung adenocarcinoma (LUAD), a major subtype of non-small cell lung cancer known for its low 5-year survival rate of 22%. By employing a comprehensive methodological approach, we analyzed bulk RNA sequencing data from 513 LUAD and 59 non-tumorous tissues, identifying 2,688 differentially expressed genes. Using Mendelian randomization (MR), we identified 74 genes with strong evidence for a causal effect on risk of LUAD. Survival analysis on these genes revealed significant differences in survival rates for 13 of them. Our pathway enrichment analysis highlighted their roles in immune response and cell communication, deepening our understanding. We also utilized single-cell RNA sequencing (scRNA-seq) to uncover cell type-specific gene expression patterns within LUAD, emphasizing the tumor microenvironment's heterogeneity. Pseudotime analysis further assisted in assessing the heterogeneity of tumor cell populations. Additionally, protein-protein interaction (PPI) network analysis was conducted to evaluate the potential druggability of these identified genes. The culmination of our efforts led to the identification of five genes (tier 1) with the most compelling evidence, including SECISBP2L, PRCD, SMAD9, C2orf91, and HSD17B13, and eight genes (tier 2) with convincing evidence for their potential as therapeutic targets.

Concomitant double-fusion of PLEKHA7-ALK and INPP5D-ALK reveals favorable alectinib sensitivity in lung adenocarcinoma: a case report and literature review

Anaplastic lymphoma kinase (ALK) gene fusion is a classic driver mutation in non-small cell lung cancer (NSCLC); however, ALK double-fusion variants in NSCLC have rarely been reported. In this study, we reported a case with extremely uncommon ALK double-fusion variants. A 32-year-old female diagnosed with lung adenocarcinoma, who had developed multiple intrapulmonary and brain metastases, experienced worsening of her condition despite undergoing prior chemotherapy. Subsequent testing using next-generation sequencing (NGS) detected the presence of PLEKHA7-ALK and INPP5D-ALK double-fusion. The prescription of alectinib revealed potent efficacy and resulted in an increase in the survival rate. This case presented two uncommon and concomitant ALK fusion partners in NSCLC; more importantly, the INPP5D-ALK subtype has not been reported, therefore this study broadens the spectrum of ALK double-fusion variants and provides insight into the use of ALK inhibitors for the treatment of NSCLC in patients with double ALK fusions.