Wei Jiang

Despite the widely reported experimental anti‐tumor effects, metformin's role remains exceedingly complex, with contradictory results in clinical trials. Our study, based on metabolomics analysis of lung adenocarcinoma (LUAD) samples, xenografts, and cells, unveils a novel process that metformin promotes the conversion of UDP‐glucose (UDPG) to UDP‐glucuronic acid (UDPGA) in glucuronic acid metabolism. Mechanistically, metformin activates UDP‐glucose 6‐dehydrogenase (UGDH) through AMPK‐mediated phosphorylation of UGDH(S476), a previously unstudied phosphorylation site, impeding the binding of UDP‐Xyl to UGDH and the subsequent allosteric inhibition. Consequently, metformin‐treated cells are more reliant on UXS1, a downstream metabolic enzyme of UGDH, for detoxifying UDPGA based on the “kitchen‐sink” model. Through comprehensive virtual screening of a compound library, we identified that plantainoside is a potent UXS1‐targeting agent. Remarkably, when combined with metformin, plantainoside exhibits a superior synergistic lethal effect in LUAD cells, organoids, xenografts, and spontaneous models. Moreover, this combination not only directly targets tumor cells but also synergistically boosts CD8+ T cells and suppresses the differentiation of macrophages, thereby significantly enhancing immunotherapy efficacy. Collectively, our results shed light on metformin's complicated role by revealing its novel impact on glucuronic acid metabolism and dependence on UXS1; thus, targeting UXS1 combined with metformin represents a highly promising new strategy.

Lung adenocarcinoma, one of the most prevalent malignancies, underscores the urgency of identifying genes linked to its proliferation and prognosis for developing targeted therapies. In this study, we performed genome-wide CRISPR/Cas9 screening both in vitro and in vivo, and subsequently cross-referenced the findings with prognosis-related genes in lung adenocarcinoma. The screening results revealed that DEFB1 promotes lung adenocarcinoma proliferation, while our integrated analysis of single-cell sequencing, multiplex immunohistochemistry, TCGA, and GEO data concurrently demonstrated elevated DEFB1 expression in cancer cells, along with a negative correlation between DEFB1 expression and patient survival. Subsequently, functional studies employing DEFB1 knockout cells, re-expressed DEFB1 cells, and knockout cells supplemented with exogenous DEFB1 revealed that DEFB1 significantly enhances cell proliferation, migration, and invasion. Co-immunoprecipitation combined with mass spectrometry experiments was performed to uncover the mechanism of DEFB1, demonstrating that it interacts with Periplakin (PPL) to induce epithelial-to-mesenchymal transition (EMT) and proliferation, while simultaneously binding to Macrophage Migration Inhibitory Factor (MIF) to enhance M2 macrophage polarization. Furthermore, we developed multiple anti-DEFB1 monoclonal antibodies and found one of them, mAb-5, potently blocked DEFB1’s function and inhibited lung adenocarcinoma progression in cell lines, organoids, xenografts, and spontaneous lung cancer models, while maintaining a favorable safety profile. Overall, our study identifies DEFB1 as a novel driver of lung adenocarcinoma, and the anti-DEFB1 monoclonal antibody mAb-5 emerges as a promising therapeutic candidate with significant potential.

The resistance to KRAS-targeted therapies, particularly due to co-occurring gene mutations, remains a significant challenge. Through a metabolite library screening, we reveal that polyamines sensitize KRAS inhibitors only in KRAS^MU/KEAP1^WT cells but not in KRAS^MU/KEAP1^MU cells. Transcriptome sequencing and metabolome profiling pinpoint SAT1, the key enzyme in polyamine metabolism, as essential for this divergence. In KRAS^MU/KEAP1^WT context, treatment of KRAS inhibitors activates JNK/c-Jun pathway and SAT1 expression, while the augmented SAT1 facilitates polyamine metabolism and KRAS inhibitors-induced ferroptosis. Conversely, in KRAS^MU/KEAP1^MU cells, activated JNK promotes the degradation of NRF2, thereby inhibiting SAT1 expression. Our results further demonstrate that polyamine supplementation enhances KRAS-targeted therapy in KRAS^MU/KEAP1^WT resistant cells, patient-derived organoids, xenografts, and spontaneously tumorigenic mice, while KRAS^MU/KEAP1^MU models require lentivirus or adeno-associated virus-mediated SAT1 overexpression prior to polyamine treatment, to augment ferroptosis and drug sensitivity. Our findings highlight SAT1-mediated polyamine metabolism as a promising target in precision treatments for KRAS-mutant cancers.

Background: Third‐generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) show initial efficacy in EGFR‐mutated lung cancer, but residual disease persists. This study aimed to investigate cluster of differentiation 24 (CD24) as a translational immunotherapeutic target for enhancing third‐generation EGFR‐TKI efficacy. Methods: We conducted RNA‐sequencing (RNA‐seq) on drug‐responsive, drug‐tolerant persister, and drug‐resistant cells to identify therapeutic targets to pair with EGFR‐TKIs. For validation, we integrated single‐cell RNA‐seq data from 29 lung cancer specimens and used single‐nucleus RNA‐seq and immunohistochemistry on clinical residual tumor samples following TKI therapy (TKI‐residual). With CRISPR/Cas9, we studied the effect of CD24 on proliferation and phagocytic clearance during EGFR‐TKI treatment. We tested CD24 knockout or ATG‐031 (a first‐in‐class CD24 antibody) with EGFR‐TKIs in vitro, xenografts, and spontaneous lung cancer models. To explore mechanisms, we used DNA affinity precipitation, chromatin immunoprecipitation sequencing, and luciferase assays to identify transcription factors regulating CD24. Co‐immunoprecipitation combined with mass spectrometry and phosphoproteomics were used to study YIN‐YANG‐1 (YY1) S247 phosphorylation's expression and function, while kinase inhibitors assessed upstream phosphorylation of YY1 S247 and its regulation of CD24. Results: CD24 expression rose in drug‐responsive, ‐resistant, and ‐tolerant lung cancer cells and post‐EGFR‐TKI treatment clinical specimens. This elevation promoted cell proliferation and shielded tumor cells from macrophage‐mediated phagocytosis. Genetic depletion of CD24 or treatment with ATG‐031 significantly enhanced phagocytosis and tumor eradication in vitro, in xenografts, and in mice harboring EGFRL858R·T790M‐driven spontaneous lung tumors. Furthermore, we revealed that YY1 S247 phosphorylation was responsible for the upregulation of CD24 upon EGFR‐TKI treatment, facilitating YY1 dimerization and the formation of promoter‐enhancer loops that regulate CD24 expression. Conclusions: CD24 is a promising target in EGFR‐mutated lung cancers, potentially enhancing efficacy of third‐generation EGFR‐TKIs.

Ferroptosis, an iron-dependent form of cell death, holds promise for cancer therapy. However, the intricate link between ferroptosis and oncogenic mutations remains unclear. Here we show that SMARCA4, a well-established tumour suppressor whose deficiency is associated with poor prognosis and resistance to treatments, sensitizes non-small cell lung cancer (NSCLC) cells to ferroptosis. Mechanistically, SMARCA4 promotes chromatin accessibility and expression of ALDH16A1. Surprisingly, ALDH16A1 lacks ALDH enzymatic activity, but binds to the anti-ferroptotic oxidoreductase thioredoxin (TXN), facilitating its translocation to the lysosome and subsequent degradation. Meanwhile, ALDH16A1 directly inhibits TXN's oxidoreductase function by occluding its active site. We also show that either restoring ALDH16A1 levels or inhibiting TXN significantly enhances the effectiveness of chemo/immunotherapy in a ferroptosis-dependent manner in SMARCA4-deficient NSCLC. Collectively, our findings elucidate an intricate SMARCA4-ALDH16A1-TXN stability/function dual regulatory axis that governs ferroptosis and informs a therapeutic strategy for overcoming resistance to chemotherapy or immunotherapy in SMARCA4-deficient NSCLC.

Human epidermal growth factor receptor 2 (HER2) mutations have been identified as oncogenic drivers and therapeutic targets in Non-small cell lung cancers (NSCLCs). The role of HER2 mutation in lung adenocarcinoma presented as sub-solid nodules (SSNs) have not been distinctly defined. This study comprehensively investigated the clinicopathological characteristics of HER2 mutation in patients with pulmonary SSNs. In total, 717 patients with completely resected NSCLCs presented as SSNs were examined for HER2 mutation from January 2016 to December 2018. Age, sex, smoking history, radiologic features, operative procedure, pleural invasion, histologic subtypes and tumor-node-metastasis stage were collected. Kaplan-Meier method was used to estimate DFS, Log-rank test was used to compare the survival data. Logistic regression model was used to identify the predictors for HER2 mutation and the predictive nomogram was built. In this study, 47(6.6%) SSNs carried HER2 mutations. HER2 mutations were more frequent in subjects with younger age (P < 0.001) and smaller tumor size (P < 0.001), and were prone to occur in AIS and MIA (P < 0.001). The 5- year DFS rates for HER2 mutation and HER2 wild-type groups were similar (P = 0.509). According to the logistic regression analysis, age and maximum tumor size were independent variables correlated with HER2 mutation. A predictive nomogram model was constructed with a concordance statistic of 0.79 (0.71–0.87). HER2 mutation was not uncommon in pulmonary SSNs. Younger age and smaller tumor size were associated with increased odds of HER2 mutation.

Metformin has been found to have inhibitory effects on a variety of tumors. However, its effects on non-small cell lung cancer (NSCLC) remain unclear. We demonstrated that metformin could inhibit the proliferation of A549 and H1299 cells. RNA transcriptome sequencing revealed that PDL1 was significantly downregulated in both cell types following treatment with metformin (P < 0.001). Jaspar analysis and chromatin immunoprecipitation showed that CEBPB could directly bind the promoter region of PDL1. Western blotting showed that protein expression of the isoforms CEBPB-LAP*, CEBPB-LAP, and CEBPB-LIP was significantly upregulated and the LIP/LAP ratio was increased. Gene chip analysis showed that PDL1 was significantly upregulated in A549-CEBPB-LAP cells and significantly downregulated in A549-CEBPB-LIP cells (P < 0.05) compared with CEBPB-NC cells. Dual-luciferase reporter gene assay showed that CEBPB-LAP overexpression could promote transcription of PDL1 and CEBPB-LIP overexpression could inhibit the process. Functional assays showed that the changes in CEBPB isoforms affected the function of NSCLC cells. Western blotting showed that metformin could regulate the function of NSCLC cells via AMPK–CEBPB–PDL1 signaling. Animal experiments showed that tumor growth was significantly inhibited by metformin, and atezolizumab and metformin had a synergistic effect on tumor growth. A total of 1247 patients were retrospectively analyzed, including 166 and 1081 patients in metformin and control groups, respectively. The positive rate of PDL1 was lower than that of the control group (HR = 0.338, 95% CI = 0.235–0.487; P < 0.001). In conclusion, metformin inhibited the proliferation of NSCLC cells and played an anti-tumor role in an AMPK–CEBPB–PDL1 signaling-dependent manner.

OBJECTIVES: The cervicothoracic junction is a special section that connects the neck, thoracic cavity, mediastinum and axilla. Tumours in the region often invade or compress surrounding tissues and organs, which makes the surgical treatment difficult. METHODS: A retrospective analysis involving 69 patients with tumours at the cervicothoracic junction. Clinical data with regard to manifestation, surgical approach, resection degree, outcome and pathological types were collected. RESULTS: A total of 48 cases of asymptomatic patients and 21 cases of patients with ≥1 clinical manifestation were enrolled in the study. Twenty-seven patients received radical resection with video-assisted thoracoscopic surgery. Anterior approach was the predominant treatment method in open surgery (25 cases, 36.2%), while the anterolateral approach was used in 8 cases (6 cases of hemiclamshell incisions and 2 cases of trap-door incisions). In addition, we observed 1 case of posterior approach, 2 cases of posterolateral approach and 1 case of supraclavicular approach combined with posterolateral approach. Pathological examination results revealed 67 cases of radical resection and 2 cases of microscopic residual. Neurilemmoma was the most widespread pathological type (30 cases, 43.5%), followed by tumour originating from fibrous tissues (5 cases, 7.2%). A 3-year overall survival rate of the 69 patients was 89.9%, while a 5-year overall survival rate was 85.5%. CONCLUSIONS: Tumours associated with the cervicothoracic junction are characterized by their unique location, complex anatomy and various histopathological subtypes. An individualized approach during surgery enhances safety and standardized of treatments for patients with tumours located at the cervicothoracic junction.