Conventional neoadjuvant chemotherapy provides limited benefit for patients with resectable non-small cell lung cancer (NSCLC). Recently, neoadjuvant chemoimmunotherapy (NCIT) has transformed the perioperative management of NSCLC by priming systemic anti-tumor immunity before surgery, yet it remains ineffective for at least 50% of patients. Through single-cell sequencing analysis of our NCIT cohort, we identify that antigen-presenting cancer-associated fibroblasts (apCAFs) can impede the efficacy of NCIT. Using a custom cancer-associated fibroblast biobank, we uncover that interferon (IFN)-γ stimulates apCAF expansion via the JAK1/2-STAT1-IFI6/27 pathway. Mechanistically, apCAFs significantly contribute to PD-L2 expression in the tumor microenvironment (TME), triggering the accumulation of FOXP1⁺regulatory T cells (Tregs) through the PD-L2-RGMB axis. Reprogramming apCAFs by inhibiting the IFN-γ pathway or blocking the PD-L2-RGMB axis substantially mitigates apCAFs-mediated FOXP1⁺Tregs' expansion. In summary, we reveal the role of apCAFs in compromising NCIT efficacy and propose applications for anti-PD-L2/RGMB regimens to synergize with anti-PD1 therapies by targeting apCAFs.

Background: Epithelial-to-mesenchymal transition (EMT) contributes to the invasion and metastasis of epithelial tumors. Sirtuin 6 (SIRT6), an NAD-dependent deacetylase, is known to promote metastasis of non-small cell lung cancer (NSCLC). Methods: In this work, we determined the role of SIRT6 in the EMT of NSCLC cells and identified the key EMT-related genes involved in the oncogenic activity of SIRT6. Results: We report that depletion of SIRT6 inhibits transforming growth factor-β1 (TGF-β1)-induced EMT in A549 and H1299 NSCLC cells, which is rescued by ectopic expression of SIRT6. Knockdown of SIRT6 leads to a reduction in Snail protein without affecting the mRNA level. Immunoprecipitation experiments demonstrate a physical association between SIRT6 and Snail. SIRT6 deacetylates Snail and prevents its proteasomal degradation. Silencing of Snail blunts SIRT6-induced NSCLC cell migration and invasion, while overexpression of Snail restores the invasion and EMT in SIRT6-depleted NSCLC cells. SIRT6 depletion leads to an upregulation of kruppel-like factor 4 (KLF4) and reduced Snail binding to the promoter of Klf4 in NSCLC cells. Knockdown of KLF4 rescues the invasive capacity in SIRT6-depleted NSCLC cells. Conversely, co-expression of KLF4 impairs SIRT6-induced aggressive behavior. In vivo data further demonstrate that SIRT6-induced NSCLC metastasis is antagonized by overexpression of KLF4. Conclusions: These findings provide mechanistic insights into the pro-metastatic activity of SIRT6 and highlight the role of the SIRT6/Snail/KLF4 axis in regulating EMT and invasion of NSCLC cells.

For patients with advanced/metastatic non-small-cell lung cancer (NSCLC) without actionable genomic alterations and low (<50%) PD-L1 expression, pembrolizumab plus pemetrexed and platinum chemotherapy is a preferred first-line treatment. These patients have comparatively worse outcomes than those with higher PD-L1 expression, underscoring the need for new combination strategies. Datopotamab deruxtecan (Dato-DXd), a TROP2-directed antibody-drug conjugate, has demonstrated encouraging antitumor activity and safety in this patient population. We describe the rationale and design of TROPION-Lung07, a randomized, open-label Phase III study assessing Dato-DXd in combination with pembrolizumab with/without platinum-based chemotherapy versus pembrolizumab plus pemetrexed and platinum-based chemotherapy in patients with advanced/metastatic non-squamous NSCLC without actionable genomic alterations and <50% PD-L1 expression. Primary study objectives are progression-free survival and overall survival.Clinical Trial Registration: NCT05555732 (ClinicalTrials.gov).

With the revolutionary progress of immune checkpoint inhibitors (ICIs) in non–small cell lung cancer, identifying patients with cancer who would benefit from ICIs has become critical and urgent. Here, we report protein tyrosine phosphatase receptor type T (PTPRT) loss as a precise and convenient predictive marker independent of PD-L1 expression for anti–PD-1/PD-L1 axis therapy. Anti–PD-1/PD-L1 axis treatment markedly increased progression-free survival in patients with PTPRT-deficient tumors. PTPRT-deficient tumors displayed cumulative DNA damage, increased cytosolic DNA release, and higher tumor mutation burden. Moreover, the tyrosine residue 240 of STING was identified as a direct substrate of PTPRT. PTPRT loss elevated phosphorylation of STING at Y240 and thus inhibited its proteasome-mediated degradation. PTPRT-deficient tumors released more IFN-β, CCL5, and CXCL10 by activation of STING pathway and increased immune cell infiltration, especially of CD8 T cells and natural killer cells, ultimately enhancing the efficacy of anti–PD-1 therapy in multiple subcutaneous and orthotopic tumor mouse models. The response of PTPRT-deficient tumors to anti–PD-1 therapy depends on the tumor-intrinsic STING pathway. In summary, our findings reveal the mechanism of how PTPRT-deficient tumors become sensitive to anti–PD-1 therapy and highlight the biological function of PTPRT in innate immunity. Considering the prevalence of PTPRT mutations and negative expression, this study has great value for patient stratification and clinical decision-making.

Accurate detection of circulating tumor cells (CTCs) in blood and non-blood body fluids enables generation of deterministic cancer diagnosis and represent a less invasive and safer liquid biopsy approach. Although genomic alternations have been widely used in circulating tumor DNA (ctDNA) analysis, studies on cell-based genomic alternations profiling for CTC detection are rare due to major technical limitations in single-cell whole genome sequencing (WGS) including low throughput, low accuracy and high cost. We report a single-cell low-pass WGS-based protocol (scMet-Seq) for sensitive and accurate CTC detection by combining a metabolic function-associated marker Hexokinase 2 (HK2) and a Tn5 transposome-based WGS method with improved cell fixation strategy. To explore the clinical use, scMet-Seq has been investigated with blood and non-blood body fluids in diagnosing metastatic diseases, including ascites-based diagnosis of malignant ascites (MA) and blood-based diagnosis of metastatic small-cell lung cancer (SCLC). ScMet-Seq shows high diagnostic sensitivity (MA: 79% in >10 cancer types; metastatic SCLC: 90%) and ~100% of diagnostic specificity and positive predictive value, superior to clinical cytology that exhibits diagnostic sensitivity of 52% in MA diagnosis and could not generate blood-based diagnosis. ScMet-Seq represents a liquid biopsy approach for deterministic cancer diagnosis in different types of cancers and body fluids.

Purpose: SMARCA4‐deficient thoracic tumors, characterized by distinct clinicopathological, morphological, immunohistochemical, and genetic features, differ significantly from conventional non‐small‐cell lung carcinomas (NSCLCs). This group encompasses both SMARCA4‐deficient NSCLCs (SMARCA4‐NSCLCs) and SMARCA4‐deficient undifferentiated tumors (SMARCA4‐UTs). The efficacy of PD‐1 inhibitors in treating SMARCA4‐deficient thoracic tumors remains uncertain.Methods: Medical records of 36 patients diagnosed with stage IIIB, IIIC, or IV SMARCA4‐deficient thoracic tumors were analyzed. We assessed the clinical, pathological, and genetic features of these patients through immunohistochemistry (IHC) and a 68‐gene panel next‐generation sequencing (NGS). We compared the differences between SMARCA4‐NSCLCs and SMARCA4‐UTs, and evaluated the impact of chemotherapy and immunotherapy on patient outcomes.Results: The majority of patients with SMARCA4‐deficient thoracic tumors were heavy‐smoking males, averaging 64.6 years in age. IHC predominantly showed weak or negative staining for markers such as TTF‐1, CK5/6, p40, synaptophysin, chromogranin A, and CD56, which are often associated with adenocarcinoma, squamous cell carcinoma, and neuroendocrine tumors. The most common genetic mutations identified via NGS included TP53, CDKN2A, KRAS, STK11, NF1, and PTEN. No significant overall survival (OS) difference was observed between SMARCA4‐NSCLCs and SMARCA4‐UTs (p = 0.366). The median OS for patients treated with chemotherapy (n = 9) was 447 days, while the median OS for patients undergoing PD‐1‐inhibitor‐based therapy (n = 16) was not reached (p = 0.105).Conclusion: SMARCA4‐deficient thoracic tumors exhibit distinct characteristics from conventional NSCLCs, and PD‐1 inhibitors show promise in treating advanced SMARCA4‐deficient thoracic tumors.