Proteogenomic characterization of small cell lung cancer identifies biological insights and subtype-specific therapeutic strategies.

We performed comprehensive proteogenomic characterization of small cell lung cancer (SCLC) using paired tumors and adjacent lung tissues from 112 treatment-naive patients who underwent surgical resection. Integrated multi-omics analysis illustrated cancer biology downstream of genetic aberrations and highlighted oncogenic roles of FAT1 mutation, RB1 deletion, and chromosome 5q loss. Two prognostic biomarkers, HMGB3 and CASP10, were identified. Overexpression of HMGB3 promoted SCLC cell migration via transcriptional regulation of cell junction-related genes. Immune landscape characterization revealed an association between ZFHX3 mutation and high immune infiltration and underscored a potential immunosuppressive role of elevated DNA damage response activity via inhibition of the cGAS-STING pathway. Multi-omics clustering identified four subtypes with subtype-specific therapeutic vulnerabilities. Cell line and patient-derived xenograft-based drug tests validated the specific therapeutic responses predicted by multi-omics subtyping. This study provides a valuable resource as well as insights to better understand SCLC biology and improve clinical practice.

The impact of oncogenic driver mutations on neoadjuvant immunotherapy outcomes in patients with resectable non-small cell lung cancer.

BACKGROUND: Neoadjuvant immunotherapy has been demonstrated to be effective and safe in resectable non-small cell lung cancer (NSCLC) patients. However, the presence of different oncogenic driver mutations may affect the tumor microenvironment and consequently influence the clinical benefit from immunotherapy. METHODS: This retrospective study included consecutive NSCLC patients (stage IIA to IIIB) who underwent radical surgery after receiving neoadjuvant immunotherapy at a single high-volume center between December 2019 and August 2022. Pathological response and long-term outcomes were compared based on the driver oncogene status, and RNA sequencing analysis was conducted to investigate the transcriptomic characteristics before and after treatment. RESULTS: Of the 167 patients included in this study, 47 had oncogenic driver mutations. KRAS driver mutations were identified in 28 patients, representing 59.6% of oncogenic driver mutations. Of these, 17 patients had a major pathological response, which was significantly higher than in the non-KRAS driver mutation group (60.7% vs. 31.6%, P = 0.049). Multivariate Cox regression analysis further revealed that the KRAS driver mutation group was an independent prognostic factor for prolonged disease-free survival (hazard ratio: 0.10, P = 0.032). The median proportion of CD8+ T cells was significantly higher in the KRAS driver mutation NSCLCs than in the non-driver mutation group (18% vs. 13%, P = 0.030). Furthermore, immune-related pathways were enriched in the KRAS driver mutation NSCLCs and activated after immunotherapy. CONCLUSION: Our study suggests that NSCLC patients with KRAS driver mutations have a superior response to neoadjuvant immunotherapy, possibly due to their higher immunogenicity. The findings highlight the importance of considering oncogenic driver mutations in selecting neoadjuvant treatment strategies for NSCLC patients.

Correction: RNF111-facilitated neddylation potentiates cGAS-mediated antiviral innate immune response.

[This corrects the article DOI: 10.1371/journal.ppat.1009401.].

RNF111-facilitated neddylation potentiates cGAS-mediated antiviral innate immune response.

The cytosolic DNA sensor cyclic GMP-AMP (cGAMP) synthetase (cGAS) has emerged as a fundamental component fueling the anti-pathogen immunity. Because of its pivotal role in initiating innate immune response, the activity of cGAS must be tightly fine-tuned to maintain immune homeostasis in antiviral response. Here, we reported that neddylation modification was indispensable for appropriate cGAS-STING signaling activation. Blocking neddylation pathway using neddylation inhibitor MLN4924 substantially impaired the induction of type I interferon and proinflammatory cytokines, which was selectively dependent on Nedd8 E2 enzyme Ube2m. We further found that deficiency of the Nedd8 E3 ligase Rnf111 greatly attenuated DNA-triggered cGAS activation while not affecting cGAMP induced activation of STING, demonstrating that Rnf111 was the Nedd8 E3 ligase of cGAS. By performing mass spectrometry, we identified Lys231 and Lys421 as essential neddylation sites in human cGAS. Mechanistically, Rnf111 interacted with and polyneddylated cGAS, which in turn promoted its dimerization and enhanced the DNA-binding ability, leading to proper cGAS-STING pathway activation. In the same line, the Ube2m or Rnf111 deficiency mice exhibited severe defects in innate immune response and were susceptible to HSV-1 infection. Collectively, our study uncovered a vital role of the Ube2m-Rnf111 neddylation axis in promoting the activity of the cGAS-STING pathway and highlighted the importance of neddylation modification in antiviral defense.

The E3 ubiquitin ligase AMFR and INSIG1 bridge the activation of TBK1 kinase by modifying the adaptor STING.

Stimulator of interferon genes (STING, also known as MITA, ERIS, or MPYS) is essential for host immune responses triggered by microbial DNAs. However, the regulatory mechanisms underlying STING-mediated signaling are not fully understood. We report here that, upon cytoplasmic DNA stimulation, the endoplasmic reticulum (ER) protein AMFR was recruited to and interacted with STING in an insulin-induced gene 1 (INSIG1)-dependent manner. AMFR and INSIG1, an E3 ubiquitin ligase complex, then catalyzed the K27-linked polyubiquitination of STING. This modification served as an anchoring platform for recruiting TANK-binding kinase 1 (TBK1) and facilitating its translocation to the perinuclear microsomes. Depletion of AMFR or INSIG1 impaired STING-mediated antiviral gene induction. Consistently, myeloid-cell-specific Insig1(-/-) mice were more susceptible to herpes simplex virus 1 (HSV-1) infection than wild-type mice. This study uncovers an essential role of the ER proteins AMFR and INSIG1 in innate immunity, revealing an important missing link in the STING signaling pathway.

Safety and effectiveness of neoadjuvant PD-1 inhibitor (toripalimab) plus chemotherapy in stage II-III NSCLC (LungMate 002): an open-label, single-arm, phase 2 trial.

BACKGROUND: This trial aimed to analyse the safety, effectiveness and transcriptomic characteristics of neoadjuvant toripalimab plus chemotherapy in II-III non-small-cell lung cancer (NSCLC). METHODS: Patient eligibility mainly involved treatment-naive, clinical stage II-III and wild-type EGFR/ALK NSCLC. The patients received 2-4 cycles of toripalimab (240 mg q3w) plus carboplatin-based chemotherapy. After the second treatment cycle, all patients were re-evaluated by a multidisciplinary team. Candidates eligible for surgery underwent surgery; otherwise, patients received the remaining treatment cycles. The primary endpoints were safety and major pathological response (MPR). Secondary endpoints were R0 resection rate, progression-free survival (PFS) and overall survival (OS). RNA sequencing of baseline and post-treatment samples was conducted to explore the transcriptomic characteristics of the therapeutic response. RESULTS: In total, 50 eligible patients were enrolled, including 12 (24.0%) with resectable disease (RD) and 38 (76.0%) with potentially resectable disease (PRD). Treatment-related adverse events (TRAEs) were recorded in 48 cases (96.0%). Severe TRAEs occurred in 3 (6.0%) cases, including myelosuppression, drug-induced liver injury and death related to haemoptysis. The objective response rate (ORR) was 76.0%, with 8 (16.0%) patients having a complete response (CR), 30 (60.0%) partial response (PR), 10 (20.0%) stable disease (SD) and 2 (4.0%) progressive disease (PD). Surgery could be achieved in 12 (100%) patients with RD and 25 (65.8%) with PRD; 1 (2.0%) with PRD refused surgery. Therefore, R0 resection was performed for all 36 (100%) patients who underwent surgery; 20 (55.6%) achieved MPR, including 10 (27.8%) with a complete pathological response (pCR). The CHI3L1 (chitinase-3-like protein 1) immunohistochemistry (IHC) expression of baseline tumour samples could predict the therapeutic response (AUC=0.732), OS (P=0.017) and PFS (P=0.001). Increased PD-1 expression, T cell abundance and immune-related pathway enrichment were observed in post-treatment samples compared to baseline in the response group (CR+PR) but not in the non-response group (SD+PD). CONCLUSIONS: Neoadjuvant toripalimab plus chemotherapy was safe and effective, with a high MPR and manageable TRAEs for II-III NSCLC, even converting initially PRD to RD. Disparate transcriptomic characteristics of therapeutic efficiency were observed, and CHI3L1 expression predicted therapeutic response and survival. TRIAL REGISTRATION: ChiCTR1900024014, June 22, 2019.

Comparative profiling of single-cell transcriptome reveals heterogeneity of tumor microenvironment between solid and acinar lung adenocarcinoma.

BACKGROUND: The diversity of histologic composition reflects the inter- and intra-tumor heterogeneity of lung adenocarcinomas (LUADs) macroscopically. Insights into the oncological characteristics and tumor microenvironment (TME) of different histologic subtypes of LUAD at the single-cell level can help identify potential therapeutic vulnerabilities and combinational approaches to improve the survival of LUAD patients. METHODS: Through comparative profiling of cell communities defined by scRNA-seq data, we characterized the TME of LUAD samples of distinct histologic subtypes, with relevant results further confirmed in multiple bulk transcriptomic, proteomic datasets and an independent immunohistochemical validation cohort. RESULTS: We find that the hypoxic and acidic situation is the worst in the TME of solid LUADs compared to other histologic subtypes. Besides, the tumor metabolic preferences vary across histologic subtypes and may correspondingly impinge on the metabolism and function of immune cells. Remarkably, tumor cells from solid LUADs upregulate energy and substance metabolic activities, particularly the folate-mediated one-carbon metabolism and the key gene MTHFD2, which could serve as a potential therapeutic target. Additionally, ubiquitination modifications may also be involved in the progression of histologic patterns. Immunologically, solid LUADs are characterized by a predominance of exhausted T cells and immunosuppressive myeloid cells, where the hypoxic, acidified and nutrient-deprived TME has a non-negligible impact. Discrepancies in stromal cell function, evidenced by varying degrees of stromal remodeling and fibrosis, may also contribute to the specific immune phenotype of solid LUADs. CONCLUSIONS: Overall, our research proposes several potential entry points to improve the immunosuppressive TME of solid LUADs, thereby synergistically potentiating their immunotherapeutic efficacy, and may provide precise therapeutic strategies for LUAD patients of distinct histologic subtype constitution.

Lymph Node Examination for Stage I Second Primary Lung Cancer Patients Who Received Second Surgical Treatment.

PURPOSE: This study aims to investigate the effect of lymph node examination on overall survival (OS) and lung cancer-specific survival (LCSS) in stage I second primary lung cancer (SPLC) patients who underwent second pulmonary resection. PATIENTS AND METHODS: We conducted a retrospective study with the Surveillance, Epidemiology, and End Results (SEER) database to identify stage I SPLC patients who received surgery from 1998 to 2015. The Kaplan-Meier method with landmark analysis and multivariable Cox regression analysis were performed to evaluate the prognostic value of lymph node examination. RESULTS: A total of 842 patients from the SEER database with stage I SPLC who underwent a second surgical treatment were included. The 5-year survival rate was 54.8% for the whole cohort. Multivariable analysis revealed that the number of lymph nodes examined (LNE) was associated with better OS and LCSS in SPLC patients after 12 months postoperatively. Patients with contralateral SPLC had significantly more nodes removed than those with ipsilateral SPLC. For contralateral SPLC, more than 10 LNE was correlated with improved long-term survival outcomes. Ipsilateral SPLC patients benefited from 4 or more LNE. However, the current analysis did not show a significant survival benefit from lymph node examination within 12 months after surgery. CONCLUSIONS: For stage I SPLC patients who received surgical treatment after initial resection, an adequate number of LNE would improve both OS and LCSS. We recommend more than 10 LNE for contralateral SPLC and at least 4 LNE for ipsilateral SPLC.

The deubiquitinase CYLD is a specific checkpoint of the STING antiviral signaling pathway.

Stimulator of interferon genes (STING) is critical for cytosolic DNA-triggered innate immunity. STING is modified by several types of polyubiquitin chains. Here, we report that the deubiquitinase CYLD sustains STING signaling by stabilizing the STING protein. CYLD deficiency promoted the K48-linked polyubiquitination and degradation of STING, attenuating the induction of IRF3-responsive genes after HSV-1 infection or the transfection of DNA ligands. Additionally, CYLD knockout mice were more susceptible to HSV-1 infection than their wild-type (WT) littermates. Mechanistically, STING translocated from the ER to the Golgi upon HSV-1 stimulation; CYLD partially accumulated with STING and interacted selectively with K48-linked polyubiquitin chains on STING, specifically removing the K48-linked polyubiquitin chains from STING and ultimately boosting the innate antiviral response. Our study reveals that CYLD is a novel checkpoint in the cGAS-STING signaling pathway and sheds new light on the dynamic regulation of STING activity by ubiquitination.

SENP7 Potentiates cGAS Activation by Relieving SUMO-Mediated Inhibition of Cytosolic DNA Sensing.

Cyclic GMP-AMP (cGAMP) synthase (cGAS, a.k.a. MB21D1), a cytosolic DNA sensor, catalyzes formation of the second messenger 2'3'-cGAMP that activates the stimulator of interferon genes (STING) signaling. How the cGAS activity is modulated remains largely unknown. Here, we demonstrate that sentrin/SUMO-specific protease 7 (SENP7) interacted with and potentiated cGAS activation. The small ubiquitin-like modifier (SUMO) was conjugated onto the lysine residues 335, 372 and 382 of cGAS, which suppressed its DNA-binding, oligomerization and nucleotidyl-transferase activities. SENP7 reversed this inhibition via catalyzing the cGAS de-SUMOylation. Consistently, silencing of SENP7 markedly impaired the IRF3-responsive gene expression induced by cGAS-STING axis. SENP7-knockdown mice were more susceptible to herpes simplex virus 1 (HSV-1) infection. SENP7 was significantly up-regulated in patients with SLE. Our study highlights the temporal modulation of the cGAS activity via dynamic SUMOylation, uncovering a novel mechanism for fine-tuning the STING signaling in innate immunity.

Endoplasmic Reticulum Protein SCAP Inhibits Dengue Virus NS2B3 Protease by Suppressing Its K27-Linked Polyubiquitylation.

Dengue viruses (DENVs) are an emerging threat to global public health. The NS2B3 protease complex of DENV has recently been shown to cleave the antiviral protein STING and thereby subvert the innate immune signaling to facilitate virus replication. Whether host cells have a mechanism to counteract this virus-mediated immunosuppression is unclear. We discovered that the K27-linked polyubiquitination of NS3 protein facilitates its recruitment of NS2B, the formation of NS2B3, and consequently the enhanced cleavage of STING. However, an endoplasmic reticulum (ER) protein, SCAP, through binding to NS2B protein, inhibits the ubiquitination of NS3, rendering NS2B3 protease incapable of binding and cleaving STING. Importantly, ectopic expression of SCAP impaired DENV infection, whereas silencing of SCAP potentiated DENV infection. Collectively, this study uncovered a novel function of SCAP of counteracting the inhibitory action of DENV NS2B3 protease on STING signaling, suggesting that modulation of SCAP levels may have therapeutic implications.IMPORTANCE This study reports the first ubiquitylation target protein in DENV, the NS3 protein, and the unique role of K27-linked polyubiquitylation in NS3's ability to recruit NS2B and formation of the NS2B3 protease complex. Additionally, this study identified novel functions of the ER protein SCAP: one is to compete with NS2B for binding to STING, and the other is to inhibit the ubiquitination of NS3. Both of these functions protect STING from being cleaved by the NS2B3 protease and thus contribute to host antiviral response.

ER Adaptor SCAP Translocates and Recruits IRF3 to Perinuclear Microsome Induced by Cytosolic Microbial DNAs.

Stimulator of interferon genes (STING, also known as MITA, ERIS or MPYS) induces the activation of TBK1 kinase and IRF3 transcription factor, upon sensing of microbial DNAs. How IRF3 is recruited onto the STING signalosome remains unknown. We report here that silencing of the ER adaptor SCAP markedly impairs the IRF3-responsive gene expression induced by STING. Scap knockdown mice are more susceptible to HSV-1 infection. Interestingly, SCAP translocates from ER, via Golgi, to perinuclear microsome in a STING-dependent manner. Mechanistically, the N-terminal transmembrane domain of SCAP interacts with STING, and the C-terminal cytosolic domain of SCAP binds to IRF3, thus recruiting IRF3 onto STING signalosome. Mis-localization of SCAP abolishes its antiviral function. Collectively, this study characterizes SCAP as an essential adaptor in the STING signaling pathway, uncovering a critical missing link in DNAs-triggered host antiviral responses.

MAVS-MKK7-JNK2 defines a novel apoptotic signaling pathway during viral infection.

Viral infection induces innate immunity and apoptosis. Apoptosis is an effective means to sacrifice virus-infected host cells and therefore restrict the spread of pathogens. However, the underlying mechanisms of this process are still poorly understood. Here, we show that the mitochondrial antiviral signaling protein (MAVS/VISA/Cardif/IPS-1) is critical for SeV (Sendai virus)-induced apoptosis. MAVS specifically activates c-Jun N-terminal kinase 2 (JNK2) but not other MAP kinases. Jnk2-/- cells, but not Jnk1-/- cells, are unable to initiate virus-induced apoptosis and SeV further fails to trigger apoptosis in MAPK kinase 7 (MKK7) knockout (Mkk7-/-) cells. Mechanistically, MAVS recruits MKK7 onto mitochondria via its 3D domain, which subsequently phosphorylates JNK2 and thus activates the apoptosis pathway. Consistently, Jnk2-/- mice, but not Jnk1-/- mice, display marked inflammatory injury in lung and liver after viral challenge. Collectively, we have identified a novel signaling pathway, involving MAVS-MKK7-JNK2, which mediates virus-induced apoptosis and highlights the indispensable role of mitochondrial outer membrane in host defenses.

Spread Through Air Spaces in Stage I Pulmonary Large Cell Neuroendocrine Carcinoma.

BACKGROUND: Pulmonary large cell neuroendocrine carcinoma (LCNEC) represents an exceptionally aggressive and infrequent variant within the realm of non-small cell lung cancer, necessitating surgical intervention as the primary therapeutic approach. However, the postoperative management strategy for early-stage patients continues to be a subject of intense debate and uncertainty. METHODS: A retrospective analysis was conducted on a cohort of patients diagnosed with LCNEC who underwent surgical resection at Shanghai Pulmonary Hospital between July 2018 and June 2022. Comprehensive assessments, encompassing univariate and multivariate analyses, were performed to evaluate the prognostic significance of these indicators in patient clinical profiles, overall survival (OS), and disease-free survival (DFS). RESULTS: A comprehensive screening effort identified 171 patients with LCNEC, with 70 stage I patients meeting the criteria for inclusion in the final cohort. Of these, 11 patients (15.7%) presented with combined LCNEC, and 59 (84.3%) exhibited pure LCNEC. Univariate and multivariate analyses both unveiled that spread through air spaces (STAS) status emerged as an independent prognostic determinant for both DFS (P = .003) and OS (P = .013), whereas histologic subtype independently predicted OS (P = .011). Subgroup survival analyses further underscored that the advantageous effects of postoperative chemotherapy were significantly pronounced exclusively among STAS-positive patients, showcasing a statistically significant enhancement in DFS (P = .047) and OS (P = .018). CONCLUSIONS: STAS may serve as an adverse prognostic factor in stage I LCNEC patients, potentially offering guidance for postoperative chemotherapy decisions.

Prognostic factors of resectable anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC) patients: a retrospective analysis based on a single center.

Background: Anaplastic lymphoma kinase (ALK)-rearranged non-small cell lung cancer (NSCLC) exhibited a higher propensity for lymph node metastasis (LNM). This study aimed to investigate risk factors of occult lymph node metastasis (OLNM) and recurrence in resectable ALK-rearranged NSCLC patients. Methods: This retrospective analysis included patients with ALK-rearranged NSCLC receiving lung resections at Shanghai Pulmonary Hospital from June 2016 to August 2021. Logistic regression analysis was used to ascertain predictors of OLNM, and Cox regression analysis to identify risk factors of recurrence. Results: A total of 603 resectable ALK-rearranged NSCLC patients were included. The mean age was 55 years old. There were 171 patients (28.4%) pathologically confirmed to have LNM, 51.5% of which were occult. Logistic regression analysis identified clinical tumor size and computed tomography (CT) density as independent factors for OLNM. Cox regression analysis showed that pleural invasion and pathological tumor size were independent prognosticators for recurrence in pathologically nodal negative patients. Among pathologically nodal positive patients, adjuvant ALK-tyrosine kinase inhibitors (TKI) showed a similar recurrence-free survival (RFS) to chemotherapy (hazard ratio, 0.454; 95% confidence interval, 0.111-1.864). Conclusions: Assessing the potential risk of OLNM is required for ALK-rearranged NSCLC patients with large tumors characterized by high CT densities. Patients with large pathological tumor size or pleural infiltration should be closely monitored despite being pathologically nodal negative. Additionally, adjuvant ALK-TKI may present a comparable RFS to chemotherapy in pathologically nodal positive patients.

Neoadjuvant camrelizumab (an anti-PD-1 antibody) plus chemotherapy or apatinib (a VEGFR-2 inhibitor) for initially unresectable stage II-III non-small-cell lung cancer: a multicentre, two-arm, phase 2 exploratory study.

This multicentre, two-arm, phase 2 study aimed to explore the efficacy and safety of neoadjuvant camrelizumab plus chemotherapy or apatinib in patients with initially unresectable stage II-III non-small-cell lung cancer (NSCLC). Eligible patients regardless of PD-L1 expression received neoadjuvant camrelizumab 200 mg and platinum-doublet chemotherapy every 3 weeks (arm A) or those with PD-L1-positive tumors received neoadjuvant camrelizumab and apatinib 250 mg once daily (arm B), for 2-4 cycles, followed by surgery. The primary endpoint was major pathological response (MPR) rate. Thirty patients in arm A and 21 in arm B were enrolled. Surgery rates were 50.0% (15/30) in arm A and 42.9% (9/21) in arm B, with all patients achieving R0 resections. Of these patients, the MPR and pathological complete response rates were both 20.0% (95% CI 4.3-48.1) in arm A and were 55.6% (95% CI 21.2-86.3) and 11.1% (95% CI 0.3-48.2) in arm B, respectively. The corresponding objective response rates were 33.3% (95% CI 11.8-61.6) and 55.6% (95% CI 21.2-86.3). With a median follow-up of 22.4 months (95% CI 19.0-26.0), the median event-free survival was not reached (NR; 95% CI 13.6-NR) in arm A and 16.8 months (95% CI 8.6-NR) in arm B. Grade 3 or above treatment-related adverse events occurred in eight (26.7%) patients in arm A and three (14.3%) in arm B. Biomarker analysis showed baseline TYROBP expression was predictive of treatment response in arm B. Neoadjuvant camrelizumab plus chemotherapy or apatinib exhibits preliminary efficacy and manageable toxicity in patients with initially unresectable stage II-III NSCLC.

The efficacy of neoadjuvant EGFR-TKI therapy combined with radical surgery for stage IIIB lung adenocarcinoma harboring EGFR mutations: A retrospective analysis based on single center.

Background: Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) could provide survival benefits for locally advanced EGFR-mutant (EGFRm) non-small cell lung cancer (NSCLC). However, the role of radical surgery for EGFR-TKI treated stage IIIB EGFRm NSCLC remains controversial. This study attempted to assess the feasibility of neoadjuvant EGFR-TKI followed by radical surgery for stage IIIB EGFRm NSCLC. Patients and Methods: Between 2013 and 2020, EGFRm lung adenocarcinoma (LUAD) patients in clinical stage IIIB undergoing neoadjuvant EGFR-TKI followed by surgery (T-S-Arm) and EGFR-TKI alone (T-Arm) were reviewed retrospectively in Shanghai Pulmonary Hospital (SPH). The chi-square test, Student's t-test or Fisher's exact test was performed for analysis of baseline characteristics. Progression-free survival (PFS) was estimated using the Kaplan-Meier analysis. Multivariate Cox regression analysis was used to identify independent predictors of progression. Results: A total of 43 patients were divided into T-S-Arm (n = 21) and T-Arm (n = 22). Patients were well-balanced between the two arms. The majority of patients were female (n = 25, 58.1%), non-smokers (n = 35, 81.4%), first-generation of EGFR-TKI treatment (n = 39, 90.7%), and exon 19 deletions (19-DEL) (n = 26, 60.5%). The median diagnostic age was 63.0 years [interquartile range (IQR), 54.0-67.5 years). At the cut-off date with June 30th 2022, median follow-up time was 28 months (IQR, 20-39 months). Neoadjuvant EGFR-TKI treatment followed by radical surgery could significantly improve the median PFS compared with patients underwent EGFR-TKI alone (23.0 months vs 14.5 months, P = 0.002). Multivariate Cox regression analysis demonstrated that radical surgery (T-S-Arm vs. T-Arm, HR: 0.406; 95% CI: 0.207-0.793, P = 0.027) was the only independent predictor for disease progression. The stratified analysis demonstrated patients with N2 disease could benefit from radical surgery (HR, 0.258; 95% CI, 0.107-0.618), especially for patients harboring L858R mutation (HR, 0.188; 95% CI, 0.059-0.604). Conclusions: For stage IIIB EGFRm NSCLC patients, the prognosis might be improved by neoadjuvant EGFR-TKI followed by radical surgery versus EGFR-TKI alone, especially for those with N2 disease and harboring L858R mutation.

The efficacy and safety of wedge resection for peripheral stage IA lung adenocarcinoma: a real-world study based on a single center.

Background: The effectiveness of segmentectomy for stage IA lung adenocarcinoma (IA-LUAD) has been well-documented. However, the efficacy and safety of wedge resection for peripheral IA-LUAD remains controversial. This study evaluated the feasibility of wedge resection in patients with peripheral IA-LUAD. Methods: Patients with peripheral IA-LUAD who underwent wedge resection by video-assisted thoracoscopic surgery (VATS) at Shanghai Pulmonary Hospital were reviewed. Cox proportional hazards modeling was performed to identify predictors of recurrence. Receiver operating characteristic (ROC) curve analysis was used to calculate the optimal cutoffs of identified predictors. Results: A total of 186 patients (female/male, 115/71; mean age, 59.9 years) were included. Mean maximum dimension of consolidation component (MCD) was 5.6 mm, consolidation-to-tumor ratio (CTR) was 37%, and mean computed tomography value of tumor (CTVt) was -285.4 HU. With a median follow-up of 67 months (interquartile range, 52-72 months), the 5-year recurrence rate was 4.84%. Ten patients occurred recurrence postoperatively. No recurrence was observed adjacent to the surgical margin. Increasing MCD, CTR, and CTVt were associated with a higher risk of recurrence, with corresponding hazard ratios (HRs) of 1.212 [95% confidence interval (CI): 1.120-1.311], 1.054 (95% CI: 1.018-1.092), and 1.012 (95% CI: 1.004-1.019) with optimal cutoffs for predicting recurrence of 10 mm, 60%, and -220 HU, respectively. When a tumor had characteristics under these respective cutoffs, no recurrence was observed. Conclusions: Wedge resection can be considered to be a safe and efficacious management strategy for patients with peripheral IA-LUAD, especially for MCD less than 10 mm, CTR less than 60% and CTVt less than -220 HU.

ASS1-Mediated Reductive Carboxylation of Cytosolic Glutamine Confers Ferroptosis Resistance in Cancer Cells.

Induction of ferroptosis, a recently defined form of nonapoptotic cell death caused by iron-dependent lipid peroxidation, has emerged as an anticancer strategy. Erastin is a ferroptosis activator that promotes cell death that not only depends on the depletion of cellular cysteine but also relies on mitochondrial oxidative metabolism of glutamine. Here, we demonstrate that ASS1, a key enzyme involved in the urea cycle, plays a crucial role in ferroptosis resistance. Loss of ASS1 increased the sensitivity of non-small cell lung cancer (NSCLC) cells to erastin in vitro and decreased tumor growth in vivo. Metabolomics analysis with stable isotope-labeled glutamine showed that ASS1 promotes reductive carboxylation of cytosolic glutamine and compromises the oxidative tricarboxylic acid cycle from glutamine anaplerosis, reducing mitochondrial-derived lipid reactive oxygen species. Moreover, transcriptome sequencing showed that ASS1 activates the mTORC1-SREBP1-SCD5 axis to promote de novo monounsaturated fatty acid synthesis by using acetyl-CoA derived from the glutamine reductive pathway. Treating ASS1-deficient NSCLC cells with erastin combined with arginine deprivation significantly enhanced cell death compared with either treatment alone. Collectively, these results reveal a previously unknown regulatory role of ASS1 in ferroptosis resistance and provide a potential therapeutic target for ASS1-deficient NSCLC. SIGNIFICANCE: ASS1 promotes reductive carboxylation of glutamine and confers ferroptosis resistance, providing multiple treatment options for ASS1-deficient non-small cell lung cancer.