Nicotine in tobacco smoke is considered carcinogenic in several malignancies including lung cancer. The high incidence of lung adenocarcinoma (LAC) in non-smokers, however, remains unexplained. Although LAC has long been less associated with smoking behavior based on previous epidemiological correlation studies, the effect of environmental smoke contributing to low-dose nicotine exposure in non-smoking population could be underestimated. Here we provide experimental evidence of how low-dose nicotine promotes LAC growth in vitro and in vivo. Screening of nicotinic acetylcholine receptor subunits in lung cancer cell lines demonstrated a particularly high expression level of nicotinic acetylcholine receptor subunit α5 (α 5-nAChR) in LAC cell lines. Clinical specimen analysis revealed up-regulation of α 5-nAChR in LAC tumor tissues compared to non-tumor counterparts. In LAC cell lines α 5-nAChR interacts with epidermal growth factor receptor (EGFR), positively regulates EGFR pathway, enhances the expression of epithelial-mesenchymal transition markers, and is essential for low-dose nicotine-induced EGFR phosphorylation. Functionally, low-dose nicotine requires α 5-nAChR to enhance cell migration, invasion, and proliferation. Knockdown of α 5-nAChR inhibits the xenograft tumor growth of LAC. Clinical analysis indicated that high level of tumor α 5-nAChR is correlated with poor survival rates of LAC patients, particularly in those expressing wild-type EGFR. Our data identified α 5-nAChR as an essential mediator for low-dose nicotine-dependent LAC progression possibly through signaling crosstalk with EGFR, supporting the involvement of environmental smoke in tumor progression in LAC patients.

Lung adenocarcinoma has a strong propensity to metastasize to the brain. The brain metastases are difficult to treat and can cause significant morbidity and mortality. Identifying patients with increased risk of developing brain metastasis can assist medical decision-making, facilitating a closer surveillance or justifying a preventive treatment. We analyzed 27 lung adenocarcinoma patients who received a primary lung tumor resection and developed metastases within 5 years after the surgery. Among these patients, 16 developed brain metastases and 11 developed non-brain metastases only. We performed targeted DNA sequencing, RNA sequencing and immunohistochemistry to characterize the difference between the primary tumors. We also compared our findings to the published data of brain-tropic and non-brain-tropic lung adenocarcinoma cell lines. The results demonstrated that the targeted tumor DNA sequencing did not reveal a significant difference between the groups, but the RNA sequencing identified 390 differentially expressed genes. A gene expression signature including CDKN2A could identify 100% of brain-metastasizing tumors with a 91% specificity. However, when compared to the differentially expressed genes between brain-tropic and non-brain-tropic lung cancer cell lines, a different set of genes was shared between the patient data and the cell line data, which include many genes implicated in the cancer-glia/neuron interaction. Our findings indicate that it is possible to identify lung adenocarcinoma patients at the highest risk for brain metastasis by analyzing the primary tumor. Further investigation is required to elucidate the mechanism behind these associations and to identify potential treatment targets.

Background: Breast cancer is a leading cause of cancer-related deaths in women, particularly those with the triple-negative (TN) phenotype. Although novel therapeutic options are emerging, most are biomarker driven. This study utilized comprehensive genomic profiling (CGP) via targeted sequencing to identify actionable alterations in a TN subcohort of the VGH-TAYLOR study. Method: The study included patients with either early-stage (defined by first-line surgery or neoadjuvant therapy) or late-stage (defined by relapse or de novo metastatic disease) breast cancer. CGP was performed using the Illumina TruSight Oncology 500 assay. The level of actionability was assessed using the European Society for Medical Oncology (ESMO) Scale of Clinical Actionability of Molecular Targets (ESCAT) criteria, with additional annotations provided by the PierianDx software and OncoKB database. Results: CGP was successfully performed on 104 TN breast cancer samples. The most common actionable genes (occurring in >10% of cases) were PIK3CA (38%), BRCA2 (25%), PTEN (13%), BRCA1 (13%), ERBB2 (12%), and ERBB3 (11%). After applying a stringent per-variant filter, these frequencies were reduced to 22%, 6%, 5%, 4%, 4%, and 1% for PIK3CA, PTEN, BRCA2, BRCA1, AKT1, and PALB2, respectively. Based on the standard cut-off of 10 mutations/megabase, 24 samples were classified as tumor mutation burden (TMB)-high, whereas 80 were TMB-low. The proportion of TMB-high cases was lower among the early-stage patients compared to the late-stage patients (19% vs. 36%, p < 0.05). Conclusion: This study demonstrates the clinical feasibility and utility of large-scale CGP, enabling the investigation of a broad range of genes and multi-gene signatures, such as TMB and microsatellite instability (MSI). The identification of actionable biomarkers offers the potential to expand therapeutic opportunities for TN breast cancer patients.

Background: Common demographic risk factors are identified in colorectal cancer (CRC) and type 2 diabetes mellitus (DM), nevertheless, the molecular link and mechanism for CRC-DM comorbidity remain elusive. Dysregulated glycogen synthase kinase-3 beta under metabolic imbalance is suggested to accelerate CRC pathogenesis/progression via regulating collpasin response mediator protein-2 (CRMP2). Accordingly, roles of CRMP2 in CRC and CRC-DM patients were investigated for elucidating the molecular convergence of CRC and DM. Methods: CRMP2 profile in tumor tissues from CRC and CRC-DM patients was investigated to explore the link between CRC and DM etiology. Meanwhile, molecular mechanism of glucose to regulate CRMP2 profile and CRC characteristics was examined in vitro and in vivo. Results: CRMP2 was significantly lower in tumor lesions and associated with advanced tumor stage in CRC-DM patients. Physiological hyperglycemia suppressed CRMP2 expression/activity and augmented malignant characteristics of CRC cells. Hyperglycemia promotes actin de-polymerization, cytoskeleton flexibility and cell proliferation/metastasis by downregulating CRMP2 profile and thus contributes to CRC disease progression. Conclusions: This study uncovers molecular evidence to substantiate and elucidate the link between CRC and T2DM, as well as characterizing the roles of CRMP2 in CRC-DM. Accordingly, altered metabolic adaptations are promising targets for anti-diabetic and cancer strategies.

The advent of novel therapeutic agents has advanced biomarker characterization in non-small-cell lung cancer (NSCLC), driving increased adoption of next-generation sequencing (NGS) technologies for molecular testing. However, comprehensive data addressing the clinical utility of different NGS platforms for NSCLC remains limited. This retrospective study analyzed real-world data from 478 Taiwanese NSCLC patients over five years, using the Oncomine Focus Assay (OFA) to assess genetic alterations. The evaluation focused on assay accuracy, limit of detection (LoD), sequencing performance, and the genetic landscape of NSCLC. The OFA achieved an NGS success rate of 80.5% (385/478), with tumor cell percentage, specimen source and FFPE block age identified as key factors affecting success. Quality metrics demonstrated robust sequencing performance, including 97.0 ± 9.6% on-target alignment, 94.7 ± 6.4% uniformity, and ≥ 500 × coverage for 98.0 ± 6.6% of amplicons. Among the 385 patients analyzed, 86.8% (334/385) were found to harbor pathogenic or likely pathogenic variants, of which 78.4% (262/334) were SNVs/Indels, 41.6% (139/334) were CNVs, 2.7% (9/334) were exon skipping alterations, and 10.2% (34/334) were gene fusions. Actionable driver mutations included EGFR mutations (46.2%, 178/385), KRAS mutations (9.4%, 36/385), ERBB2 mutations (6.8%, 26/385), ALK fusions (4.4%, 17/385), MET exon 14 skipping (2.3%, 9/385), BRAF mutations (2.3%, 9/385), ROS1 and RET fusions (1.8%, 7/385 each), and NTRK1 fusions (0.5%, 2/385). Notably, KRAS G12 C mutation was detected in 2.8% (11/385) of cases. This study demonstrates the robust performance of the OFA in identifying clinically relevant genetic alterations in NSCLC. The findings support its clinical utility in precision oncology and provide valuable insights into the genetic landscape of Asian NSCLC, enhancing personalized treatment strategies for lung cancer patients.