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TRK fusions are rare but targetable mutations which occur across a wide variety of cancer types. We report the prevalence of approximately 0.7% for NTRK-positive colorectal cancer (CRC) by genetically profiling 2519 colonic and rectal tumors. The aberrations of APC and TP53 frequently co-occurred with NTRK gene fusions, whereas RAS/BRAF oncogenic alterations and NTRK fusions were almost always mutually exclusive. NTRK-driven colorectal cancer patients demonstrated increased TMB (median = 53 mut/MB, 95% CI: 36.8-68.0 mut/MB), high microsatellite instability, and an enrichment for POLE/POLD1 mutations when compared to molecularly unstratified colorectal cancer population. These data shed light on possible future approach of multimodality treatment regimen including TRK-targeted therapy and immune checkpoint inhibitor therapy in NTRK-positive CRCs.

Transmembrane domain (TMD) mutations of ERBB2 have previously been reported in lung cancer patients in addition to well-studied kinase domain (KD) mutations, which may stabilize ERBB2 heterodimerization with other EGFR family members and favor a kinase active conformation. However, the frequency and clinical significance of ERBB2 TMD mutations in Chinese population is unknown. We prospectively analyzed the next-generation sequencing data of 34 368 Chinese lung cancer patients with different sample types, including tumor tissue, plasma, cerebrospinal fluid, and pleural effusion. Patients clinical characteristics and treatment history were retrieved from the database for further evaluation. Our findings show that ERBB2 V659/G660 mutations were detected at a frequency of 0.13% (45/34 368), of which the most frequent was V659D/E (88.9%), with a trend in nonsmokers and male. Moreover, 18% of patients (8/45) showed EGFR and/or ERBB2 amplification, whereas nine patients presented EGFR L858R or exon19 deletion. Interestingly, novel ERBB3 TMD mutation I646R was found coexisting in three patients with ERBB2 V659D and one patient with ERBB2 G660D, which might influence its heterodimerization with ERBB2 and further activate ERBB2. Four ERBB2 TMD mutation-positive patients received afatinib monotherapy or combination therapy, but showed variable responses. One patient with V659E responded well to ERBB2 inhibitor lapatinib plus capecitabine as well as subsequent afatinib treatment upon progression. Our study provides valuable insights into the distribution of ERBB2 TMD mutations by employing the largest Asian lung cancer cohort thus far. Patients with ERBB2 TMD mutations who received afatinib, a pan-ERBB inhibitor, demonstrated mixed responses, posing the urgent need to develop more effective therapeutic strategy for patients who carry ERBB2 TMD mutations.

B‐cell acute lymphoblastic leukaemia (B‐ALL) is the most prevalent hematologic malignancy in children and a leading cause of mortality. Managing B‐ALL remains challenging due to its heterogeneity and relapse risk. This study aimed to delineate the molecular features of paediatric B‐ALL and explore the clinical utility of circulating tumour DNA (ctDNA). We analysed 146 patients with paediatric B‐ALL who received systemic chemotherapy. The mutational landscape was profiled in bone marrow (BM) and plasma samples using next‐generation sequencing. Minimal residual disease (MRD) testing on day 19 of induction therapy evaluated treatment efficacy. RNA sequencing identified gene fusions in 61% of patients, including 37 novel fusions. Specifically, the KMT2A‐TRIM29 novel fusion was validated in a boy who responded well to initial therapy but relapsed after 1 year. Elevated mutation counts and maximum variant allele frequency in baseline BM were associated with significantly poorer chemotherapy response (p = 0.0012 and 0.028, respectively). MRD‐negative patients exhibited upregulation of immune‐related pathways (p < 0.01) and increased CD8+ T cell infiltration (p = 0.047). Baseline plasma ctDNA exhibited high mutational concordance with the paired BM samples and was significantly associated with chemotherapy efficacy. These findings suggest that ctDNA and BM profiling offer promising prognostic insights for paediatric B‐ALL management. [ABSTRACT FROM AUTHOR]

The article discusses the potential of using early postoperative plasma circulating tumor DNA (ctDNA) to predict tumor relapse in patients with resectable non-small cell lung cancer (NSCLC), with a focus on regional susceptibility. The study analyzes genetic attributes influencing lung cancer in the Xuanwei region of China due to high incidence linked to indoor air pollution. The research reveals distinct clinicopathological features and highlights the prognostic value of ctDNA-based molecular residue disease (MRD) in surgical NSCLC patients, emphasizing the need for personalized treatment strategies. [Extracted from the article]

Steroid hormones control important developmental processes and are linked to many diseases. To systematically identify genes and pathways required for steroid production, we performed a Drosophila genome-wide in vivo RNAi screen and identified 1,906 genes with potential roles in steroidogenesis and developmental timing. Here, we use our screen as a resource to identify mechanisms regulating intracellular levels of cholesterol, a substrate for steroidogenesis. We identify a conserved fatty acid elongase that underlies a mechanism that adjusts cholesterol trafficking and steroidogenesis with nutrition and developmental programs. In addition, we demonstrate the existence of an autophagosomal cholesterol mobilization mechanism and show that activation of this system rescues Niemann-Pick type C1 deficiency that causes a disorder characterized by cholesterol accumulation. These cholesterol-trafficking mechanisms are regulated by TOR and feedback signaling that couples steroidogenesis with growth and ensures proper maturation timing. These results reveal genes regulating steroidogenesis during development that likely modulate disease mechanisms.

Steroid hormones are ancient signaling molecules found in vertebrates and insects alike. Both taxa show intriguing parallels with respect to how steroids function and how their synthesis is regulated. As such, insects are excellent models for studying universal aspects of steroid physiology. Here, we present a comprehensive genomic and genetic analysis of the principal steroid hormone-producing organs in two popular insect models, Drosophila and Bombyx. We identified 173 genes with previously unknown specific expression in steroid-producing cells, 15 of which had critical roles in development. The insect neuropeptide PTTH and its vertebrate counterpart ACTH both regulate steroid production, but molecular targets of these pathways remain poorly characterized. Identification of PTTH-dependent gene sets identified the nuclear receptor HR4 as a highly conserved target in both Drosophila and Bombyx. We consider this study to be a critical step toward understanding how steroid hormone production and release are regulated in all animal models.

This article explores the role of Polo-like kinase 1 (PLK1) in tumorigenesis, specifically in colorectal cancer (CRC) and lung cancer. The study analyzes the mutational landscape of PLK1 and concomitant mutations in these cancers. The findings suggest that PLK1 may have tumor-suppressor features and caution should be exercised when using PLK1 inhibitors. The study also identifies different mutation subtypes of PLK1 and their associations with other genetic abnormalities in CRC. However, the study has limitations, such as missing information on cancer stage and treatment data, and further research is needed to validate the findings. [Extracted from the article]