Unravelling the biology of SCLC: implications for therapy

Clinical Progresses and Challenges of Bispecific Antibodies for the Treatment of Solid Tumors

In recent years, bispecific antibodies (BsAbs) have emerged as a promising therapeutic strategy against tumors. BsAbs can recruit and activate immune cells, block multiple signaling pathways, and deliver therapeutic payloads directly to tumor sites. This review provides a comprehensive overview of the recent advances in the development and clinical application of BsAbs for the treatment of solid tumors. We discuss the different formats, the unique mechanisms of action, and the clinical outcomes of the most advanced BsAbs in solid tumor therapy. Several studies have also analyzed the clinical progress of bispecific antibodies. However, this review distinguishes itself by exploring the challenges associated with bispecific antibodies and proposing potential solutions. As the field progresses, BsAbs hold promise to redefine cancer treatment paradigms and offer new hope to patients with solid tumors.

Tarlatamab-dlle: A New Hope for Patients with Extensive-Stage Small-Cell Lung Cancer

OPINION STATEMENT

Lung cancer is expected to contribute to about 0.234 million new cases and about 0.125 million mortalities in the United States in the year 2024. Small cell lung cancer (SCLC), a neuroendocrine carcinoma, has lesser prevalence but is more aggressive at an extensive stage where the tumor is not only confined to hemithorax, mediastinum, and supraclavicular region but spread beyond the supraclavicular region. The prognosis of SCLC, irrespective of the limited or extensive stage, is very poor. Only a 5-10% overall survival rate in five years is expected and with extensive-stage SCLC, long-term disease-free survival is rare. In May 2024, the USFDA approved Tarlatamab-dlle, a DLL3 targeted bi-specific T-cell engager, for treating extensive-stage SCLC in adult patients, on or after platinum-based chemotherapy or on progression. Before the approval of Tarlatamab-dlle, only a few drugs, such as Atezolizumab and Durvalumab, received FDA approval for treating extensive-stage SCLC. It might be possible that Tarlatamab-dlle received accelerated FDA approval for extensive-stage SCLC, leaving some questions unanswered at this stage. This manuscript is focused on clinical, pre-clinical, and other pharmacological aspects of Tarlatamab-dlle for extensive-stage SCLC.

A biomarker exploration in small-cell lung cancer for brain metastases risk and prophylactic cranial irradiation therapy efficacy

BACKGROUND

Small-cell lung cancer (SCLC) is an aggressive malignancy with a poor prognosis. Limited-stage (LS)-SCLC comprises only one-third of SCLC cases, resulting in limited molecularly targeted therapies and treatment options. Despite advances in thoracic and cranial irradiation leading to improved outcomes, a notable proportion of patients develop brain metastasis (BM), highlighting the importance of identifying high-risk patients for tailored screening and treatment strategies.

MATERIALS AND METHODS

We analyzed baseline tumor biopsies from 180 LS-SCLC patients who received frontline definitive chemoradiotherapy (dCRT) using a 474-gene pan-cancer panel. The cumulative incidence of BM was calculated with death scored as a competing risk. Independent prognostic factors for BM risk were identified using the Fine-Gray model.

RESULTS

Alterations in the cell cycle pathway, particularly RB1 mutations, were more common in patients with BM, while FLT4 mutations were more frequent in those without BM (P=0.002 and P=0.021, respectively). Significant risk factors for BM include smoking (subdistribution hazard ratio [SHR]: 1.73; 95 % confidence interval [CI]: 1.11-2.70; P=0.016), RB1 mutations (SHR: 2.19; 95 % CI: 1.27-3.81; P=0.005), and BCL3 amplification (SHR: 2.27; 95 % CI: 1.09-4.71; P=0.028). Conversely, prophylactic cranial irradiation (PCI) (SHR: 0.39; 95 % CI: 0.25-1.60; P<0.001), FLT4 mutations (SHR: 0.26; 95 % CI: 0.07-0.98; P=0.047), and NOTCH pathway alterations (SHR: 0.65; 95 % CI: 0.43-1.00; P=0.049) were associated with a lower incidence of BM in LS-SCLC. Notably, consolidation PCI therapy did not reduce the BM risk in patients with baseline RB1 mutations, with BM occurrence probabilities of 34.7 % at 20 months and 62.6 % at 40 months.

CONCLUSION

Our study yields valuable insights into the genetic characteristics of LS-SCLC patients with and without BM, aiding the development of personalized treatment strategies. Identifying risk factors associated with the incidence and timing of BM, within the standard regimen of dCRT followed by PCI, may help optimize clinical decision-making for LS-SCLC.

Treatment-related Adverse Events, Including Fatal Toxicities, in Patients With Extensive-stage Small-cell Lung Cancer Receiving Adjuvant Programmed Cell Death 1/Programmed Cell Death Ligand 1 Inhibitors: A Meta-analysis and Trial Sequential Analysis of Randomized Controlled Trials

BACKGROUND/AIMS

The safety profile of programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1) inhibitors when associated with chemotherapy for the treatment of patients with extensive-stage small-cell lung cancer is still not fully unraveled.

METHODS

We performed a comprehensive searrch of the PubMed, Embase, and Cochrane databases for randomized controlled trials that investigated the addition of PD-1 or PD-L1 inhibitors to standard investigator choice chemotherapy. We used risk -ratios (RRs) with 95% confidence intervals (CIs) for all endpoints.

RESULTS

Six studies and 2,995 patients were included. At the baseline, the median age of the patients varied from 62 to 65 years, 311 (10.4%) had brain metastases, and 1,060 (35.4%) had liver metastases. PD-1/PD-L1 inhibitors were found to reduce fatal toxicities-related mortality (RR: 0.85; 95% CI: 0.80-0.91; p < 0.001; I2 = 49%). The intervention group had a higher incidence of decreased appetite (RR: 1.19; 95% CI: 1.02-1.40; p = 0.03; I2 = 0%), hyponatremia (RR: 1.51; 95% CI: 1.08-2.12; p = 0.02; I2 = 0%), and hypothyroidism (RR: 3.14; 95% CI: 1.10-8.95; p = 0.03; I2 = 81%) of any grade. Regarding adverse events of grade 3-4, there was no association of the addition of PD-1/PD-L1 inhibitors with an increased occurrence of any of the evaluated outcomes.

CONCLUSION

In this systematic review and meta-analysis, the incorporation of PD-1/PD-L1 inhibitors to chemotherapy demonstrated an excellent safety profile and to be a promising prospect for reshaping the established treatment paradigms for patients with extensive-stage small cell lung cancer.

CDK4/6 Inhibitors Impede Chemoresistance and Inhibit Tumor Growth of Small Cell Lung Cancer

Small cell lung cancer (SCLC) is characterized by rapid development of chemoresistance and poor outcomes. Cyclin-dependent kinase 4/6 inhibitors (CDK4/6is) are widely used in breast cancer and other cancer types. However, the molecular mechanisms of CDK4/6 in SCLC chemoresistance remain poorly understood. Here, Rb1flox/flox, Trp53flox/flox, Ptenflox/flox (RTP) and Rb1flox/flox, Trp53flox/flox, MycLSL/LSL (RPM) spontaneous SCLC mouse models, SCLC cell line-derived xenograft (CDX) models, and SCLC patient-derived xenograft (PDX) models are established to reveal the potential effects of CDK4/6is on SCLC chemoresistance. In this study, it is found that CDK4/6is palbociclib (PD) or ribociclib (LEE) combined with chemotherapeutic drugs significantly inhibit SCLC tumor growth. Mechanistically, CDK4/6is do not function through the classic Retionblastoma1 (RB) dependent axis in SCLC. CDK4/6is induce impair autophagy through the AMBRA1-lysosome signaling pathway. The upregulated AMBRA1 protein expression leads to CDK6 degradation via autophagy,  and the following TFEB and TFE3 nuclear translocation inhibition leading to the lysosome-related genes levels downregulation. Moreover, it is found that the expression of CDK6 is higher in SCLC tumors than in normal tissue and it is associated with the survival and prognosis of SCLC patients. Finally, these findings demonstrate that combining CDK4/6is with chemotherapy treatment may serve as a potential therapeutic option for SCLC patients.

Efficacy and safety of anlotinib plus penpulimab as second-line treatment for small cell lung cancer: A multicenter, open-label, single-arm phase II trial

Background

Currently, the need for new therapeutic strategies involving programmed cell death protein-1 (PD-1) monoclonal antibodies in the second-line setting of small cell lung cancer (SCLC) is urgent. This study aimed to evaluate the efficacy and safety of anlotinib plus penpulimab as a second-line treatment for patients with SCLC who progressed after first-line platinum-based chemotherapy.

Methods

This study included the patients from Cohort 4 of a single-arm, open-label, multicenter, phase II clinical trial. A safety run-in phase was performed under anlotinib (10/12 mg quaque die [QD], days 1-14) plus penpulimab (200 mg intravenously [IV], day 1) in a 21-day cycle, followed by the formal trial in which the patients received anlotinib (12 mg QD, days 1-14) plus penpulimab (200 mg IV, day 1) in a 21-day cycle. The primary endpoint of the safety run-in phase was safety. The primary endpoint of the formal trial phase was the objective response rate (ORR).

Results

From April 28, 2020, to November 24, 2020, 21 patients were enrolled from 11 hospitals, including 2 in the safety run-in phase and 19 in the formal trial phase. In the formal trial phase, the ORR was 42.1% (8/19; 95% confidence interval [CI]: 17.7-66.6%). The median progression-free survival was 4.8 months (95% CI: 2.9-11.3 months), and the median overall survival was 13.0 months (95% CI: 4.6-not applicable [NA] months). The incidence of ≥grade 3 treatment-related adverse events (TRAEs) was 52.4% (11/21), and the incidence of treatment-related serious adverse events (AEs) was 28.6% (6/21). Two AE-related deaths occurred. The most common AEs were hypertension (57.1%, 12/21), hypothyroidism (42.9%, 9/21), and hypertriglyceridemia (38.1%, 8/21).

Conclusions

In patients with SCLC who progressed after first-line platinum-based chemotherapy, the second-line anlotinib plus penpulimab treatment demonstrates promising anti-cancer activity and a manageable safety profile, which warrants further investigation.

Trial registration

No. NCT04203719, https://clinicaltrials.gov/.

Recent treatment patterns and real-world survival following first-line anti-PD-L1 treatment for extensive-stage small cell lung cancer

BACKGROUND

The landscape of small cell lung cancer (SCLC) has changed since the 2019 and 2020 approvals of anti-PD-L1 atezolizumab and durvalumab for first-line (1L) treatment in combination with chemotherapy. We studied treatment patterns and real-world overall survival (rwOS) following 1L-3L therapy.

PATIENTS AND METHODS

A nationwide electronic health record (EHR)-derived de-identified database was used to describe treatment patterns, characteristics, and survival of patients with extensive-stage (ES)-SCLC by 1L anti-PD-L1 treatment. Patients with ES-SCLC who initiated ≥1 line of systemic therapy from 2013 to 2021, with potential follow-up through 2022, were included.

RESULTS

Among 9952 patients with SCLC, there were 4308 patients with ES-SCLC treated during the study period who met eligibility criteria. Etoposide + platinum (EP) chemotherapy was most common in the 1L, with addition of anti-PD-L1 therapy to most regimens by 2019. Second-line regimens varied by platinum sensitivity status and shifted from topotecan to lurbinectedin over time. Median rwOS following 1L therapy was 8.3 months (95% CI, 7.9-8.8) in those treated with 1L anti-PD-L1 and 8.0 months (95% CI, 7.8-8.2) in those who were not. Following 2L and 3L, median rwOS was 5.6 (95% CI, 4.9-6.3) and 4.9 months (95% CI, 3.4-6.0), respectively, among 1L anti-PD-L1-treated, and 4.5 (95% CI, 4.2-4.9) and 4.0 months (95% CI, 3.7-4.5), respectively, among those who were not.

CONCLUSION

Despite the introduction of frontline anti-PD-L1 therapy, survival remains dismal among patients with ES-SCLC treated in the real-world setting.

ATR inhibition activates cancer cell cGAS/STING-interferon signaling and promotes antitumor immunity in small-cell lung cancer

Patients with small-cell lung cancer (SCLC) have poor prognosis and typically experience only transient benefits from combined immune checkpoint blockade (ICB) and chemotherapy. Here, we show that inhibition of ataxia telangiectasia and rad3 related (ATR), the primary replication stress response activator, induces DNA damage-mediated micronuclei formation in SCLC models. ATR inhibition in SCLC activates the stimulator of interferon genes (STING)-mediated interferon signaling, recruits T cells, and augments the antitumor immune response of programmed death-ligand 1 (PD-L1) blockade in mouse models. We demonstrate that combined ATR and PD-L1 inhibition causes improved antitumor response than PD-L1 alone as the second-line treatment in SCLC. This study shows that targeting ATR up-regulates major histocompatibility class I expression in preclinical models and SCLC clinical samples collected from a first-in-class clinical trial of ATR inhibitor, berzosertib, with topotecan in patients with relapsed SCLC. Targeting ATR represents a transformative vulnerability of SCLC and is a complementary strategy to induce STING-interferon signaling-mediated immunogenicity in SCLC.

Identification of HEPACAM2 as a novel and specific marker of small cell carcinoma

BACKGROUND

Small cell lung cancer (SCLC) is the most aggressive neuroendocrine lung cancer, with a dismal 5-year survival rate. No reliable biomarkers or imaging are available for early SCLC detection. In a search for a specific marker of SCLC, this study identified that hepatocyte cell adhesion molecule 2 (HEPACAM2), a member of the immunoglobulin-like superfamily, is highly and specifically expressed in SCLC.

METHODS

This study investigated HEPACAM2 expression in patients with SCLC via RNA sequencing and evaluated its relationship to progression-free survival (PFS) and overall survival (OS). Immunofluorescence microscopy was used to assess the cellular location of HEPACAM2 and to conduct in vitro and in vivo studies to understand its expression and functional significance. These findings were integrated with databases of patients with SCLC.

RESULTS

HEPACAM2 is highly expressed and specific to SCLC. HEPACAM2 levels are inversely correlated with PFS and OS in patients with SCLC and are expressed at all stages. Moreover, HEPACAM2 messenger RNA and its peptides can be detected in the secretomes in cell lines. Positively correlated with ASCL1 expression in SCLC tumors, HEPACAM2 is localized primarily to the plasma membrane and linked to extracellular matrix signaling and cellular migration. A loss of HEPACAM2 in SCLC cells attenuated ASCL1 and MYC expression. Consistent with clinical data, in vitro and in vivo studies suggested that HEPACAM2 promotes cancer cell growth.

CONCLUSIONS

With its remarkable specificity, high expression, presence in early disease, and extracellular secretion, HEPACAM2 could be a potential diagnostic cell surface biomarker for early SCLC detection. These findings warrant further investigation into its role in the pathobiology of SCLC.

Deciphering the role of claudins in lung cancer

Lung cancer remains a major global health challenge, characterized by aggressive malignancy and poor prognostic outcomes. This review article focuses on the pivotal role of claudins, a family of tight junction proteins, in the pathophysiology of lung cancer. Claudins are integral to maintaining epithelial barrier function and cellular polarity, yet they are intricately involved in the progression and metastasis of lung cancer. The aberrant expression of claudins has been observed across various histological subtypes of lung cancer, indicating their potential as diagnostic and prognostic biomarkers. Specifically, claudins such as claudin-1, -2, -3, -4, and -7 exhibit diverse expression patterns that correlate with tumor aggressiveness, patient survival rates, and response to therapies. Inflammation and cytokine modulation significantly influence claudin expression, affecting tumor microenvironment dynamics and cancer progression. This review also highlights the therapeutic implications of targeting claudins, particularly in cases resistant to conventional treatments. Recent advances in this area suggest that claudin-modulating agents may enhance the efficacy of existing therapies and offer new avenues for targeted interventions. By integrating the latest research, this article aims to provide a comprehensive understanding of claudin's roles in lung cancer and encourages further clinical trials to explore claudin-targeting therapies. This could pave the way for more effective management strategies, improving outcomes for lung cancer patients.

Early Circulating Tumor DNA Shedding Kinetics for Prediction of Platinum Sensitivity in Patients With Small Cell Lung Cancer

PURPOSE

Small cell lung cancer (SCLC) is characterized by rapid progression after platinum resistance. Circulating tumor (ctDNA) dynamics early in treatment may help determine platinum sensitivity.

MATERIALS AND METHODS

Serial plasma samples were collected from patients receiving platinum-based chemotherapy for SCLC on the first 3 days of cycle one and on the first days of subsequent cycles with paired samples collected both before and again after infusions. Tumor-informed plasma analysis was carried out using CAncer Personalized Profiling by deep Sequencing (CAPP-Seq). The mean variant allele frequency (VAF) of all pretreatment mutations was tracked in subsequent blood draws and correlated with radiologic response.

RESULTS

ctDNA kinetics were assessed in 122 samples from 21 patients. Pretreatment VAF did not differ significantly between patients who did and did not respond to chemotherapy (mean 22.5% v 4.6%, P = .17). A slight increase in ctDNA on cycle 1, day 1 immediately post-treatment was seen in six of the seven patients with available draws (fold change from baseline: 1.01-1.44), half of whom achieved a response. All patients who responded had a >2-fold decrease in mean VAF on cycle 2 day 1 (C2D1). Progression-free survival (PFS) and overall survival (OS) were significantly longer in patients with a >2-fold decrease in mean VAF after one treatment cycle (6.8 v 2.6 months, log-rank P = .0004 and 21.7 v 6.4 months, log rank P = .04, respectively).

CONCLUSION

A >2-fold decrease in ctDNA concentration was observed by C2D1 in all patients who were sensitive to platinum-based therapy and was associated with longer PFS and OS.

Challenges and future perspectives for the use of temozolomide in the treatment of SCLC

Small-cell lung cancer (SCLC), accounting for 10-20 % of all lung tumors, represents the most aggressive high-grade neuroendocrine carcinoma. Most patients are diagnosed with extensive-stage SCLC (ES-SCLC), with brian metastases identified in ∼ 80 % of cases during the disease cours, and the prognosis is dismal, with a 5-year survival rate of less than 5 %. Current available treatments in the second-line setting are limited, and topotecan has long been the only FDA-approved drug in relapsed or refractory ES-SCLC, until the recent approval of lurbinectedin, a selective inhibitor of RNA polymerase II. Temozolomide (TMZ) is an oral alkylating agent, which showed single-agent activity in SCLC, particularly among patients with O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation. Several studies have revealed the synergistic activity of temozolomide with poly-ADP-ribose polymerase (PARP) inhibitors, that prevent repair of TMZ-induced DNA damage. This review focuses on the rationale for the use of TMZ in ES-SCLC and provides an overview of the main trials that have evaluated and are currently investigating its role, both as a single-agent and in combinations, in relapse or refractory disease.

Exploring public cancer gene expression signatures across bulk, single-cell and spatial transcriptomics data with signifinder Bioconductor package

Understanding cancer mechanisms, defining subtypes, predicting prognosis and assessing therapy efficacy are crucial aspects of cancer research. Gene-expression signatures derived from bulk gene expression data have played a significant role in these endeavors over the past decade. However, recent advancements in high-resolution transcriptomic technologies, such as single-cell RNA sequencing and spatial transcriptomics, have revealed the complex cellular heterogeneity within tumors, necessitating the development of computational tools to characterize tumor mass heterogeneity accurately. Thus we implemented signifinder, a novel R Bioconductor package designed to streamline the collection and use of cancer transcriptional signatures across bulk, single-cell, and spatial transcriptomics data. Leveraging publicly available signatures curated by signifinder, users can assess a wide range of tumor characteristics, including hallmark processes, therapy responses, and tumor microenvironment peculiarities. Through three case studies, we demonstrate the utility of transcriptional signatures in bulk, single-cell, and spatial transcriptomic data analyses, providing insights into cell-resolution transcriptional signatures in oncology. Signifinder represents a significant advancement in cancer transcriptomic data analysis, offering a comprehensive framework for interpreting high-resolution data and addressing tumor complexity.

Characteristics of molecular subtypes and cinical outcomes in the immunotherapy Queue of extensive-stage small cell lung cancer patients

BACKGROUND

With a series of clinical trials confirming the sensitivity of small cell lung cancer (SCLC) to immunotherapy, research on personalized treatment for SCLC has gained increasing attention. Currently, the most widely accepted subtype of SCLC is based on the expression levels of Achaete-Scute Family BHLH Transcription Factor 1 (ASCL1), neurogenic differentiation factor 1 (NEUROD1), and POU class 2 homeobox 3 (POU2F3). However, real-world studies on this classification remain limited.

METHODS

We retrospectively collected biopsy specimens from patients who received immunotherapy at Shandong Provincial Hospital between January 2019 and July 2021. After determining the patient subtypes using immunohistochemistry, we analyzed the relationships between each subtype and survival as well as some clinical characteristics.

RESULTS

In our study, we found that the subtype I achieved a significant survival advantage compared to the other groups. Additionally, the subtype A demonstrated a significant survival disadvantage. Among patients in the subtype I, there was a higher proportion of early brain metastasis and patients with a family history of tumors, while the subtype A had a lower proportion. Furthermore, the subtype A exhibited relatively poor immune infiltration.

CONCLUSION

In a diverse cohort of SCLC patients receiving immunotherapy, the subtype-I showed significant survival advantages while the subtype-A experienced a worse survival.

Mitochondrial VDAC1 Silencing in Urethane-Induced Lung Cancer Inhibits Tumor Growth and Alters Cancer Oncogenic Properties

Alterations in cellular metabolism are vital for cancer cell growth and motility. Here, we focused on metabolic reprogramming and changes in tumor hallmarks in lung cancer by silencing the expression of the mitochondrial gatekeeper VDAC1. To better mimic the clinical situation of lung cancer, we induced lung cancer in A/J mice using the carcinogen urethane and examined the effectiveness of si-m/hVDAC1-B encapsulated in PLGA-PEI nanoparticles. si-m/hVDAC1-B, given intravenously, induced metabolism reprogramming and inhibited tumor growth as monitored using MRI. Mice treated with non-targeted (NT) PLGA-PEI-si-NT showed many large size tumors in the lungs, while in PLGA-PEI-si-m/hVDAC-B-treated mice, lung tumor number and area were markedly decreased. Immunofluorescence staining showed decreased expression of VDAC1 and metabolism-related proteins and altered expression of cancer stem cell markers. Morphological analysis showed two types of tumors differing in their morphology; cell size and organization within the tumor. Based on specific markers, the two tumor types were identified as small cell (SCLC) and non-small cell (NSCLC) lung cancer. These two types of tumors were found only in control tumors, suggesting that PLGA-PEI-si-m/hVDAC1-B also targeted SCLC. Indeed, using a xenograft mouse model of human-derived SCLC H69 cells, si-m/hVDAC1-B inhibited tumor growth and reduced the expression of VDAC1 and energy- and metabolism-related enzymes, and of cancer stem cells in the established xenograft. Additionally, intravenous treatment of urethane-induced lung cancer mice with the VDAC1-based peptide, Retro-Tf-D-LP4, showed inhibition of tumor growth, and decreased expression levels of metabolism- and cancer stem cells-related proteins. Thus, silencing VDAC1 targeting both NSCLC and SCLC points to si-VDAC1 as a possible therapeutic tool to treat these lung cancer types. This is important as target NSCLC tumors undergo transformation to SCLC.

Predictive Signatures for Responses to Checkpoint Blockade in Small-Cell Lung Cancer in Second-Line Therapy Do Not Predict Responses in First-Line Patients

Although immune checkpoint blockade (ICB) is currently approved for the treatment of extensive-stage small-cell lung cancer (SCLC) in combination with chemotherapy, relatively few patients have demonstrated durable clinical benefit (DCB) to these therapies. Biomarkers predicting responses are needed. Biopsies from 35 SCLC patients treated with ICB were subjected to transcriptomic analysis; gene signatures were assessed for associations with responses. Twenty-one patients were treated with ICB in the first-line setting in combination with platinum-based chemotherapy; fourteen patients were treated in the second-line setting with ICB alone. DCB after ICB in SCLC in the second-line setting (3 of 14 patients) was associated with statistically higher transcriptomic levels of genes associated with inflammation (p = 0.003), antigen presentation machinery (p = 0.03), interferon responses (p < 0.05), and increased CD8 T cells (p = 0.02). In contrast, these gene signatures were not significantly different in the first-line setting. Our data suggest that responses to ICB in SCLC in the second-line setting can be predicted by the baseline inflammatory state of the tumor; however, this strong association with inflammation was not seen in the first-line setting. We postulate that chemotherapy alters the immune milieu allowing a response to ICB. Other biomarkers will be needed to predict responses in first-line therapy patients.

Small cell lung cancer: emerging subtypes, signaling pathways, and therapeutic vulnerabilities

Small cell lung cancer (SCLC) is a recalcitrant cancer characterized by early metastasis, rapid tumor growth and poor prognosis. In recent decades, the epidemiology, initiation and mutation characteristics of SCLC, as well as abnormal signaling pathways contributing to its progression, have been widely studied. Despite extensive investigation, fewer drugs have been approved for SCLC. Recent advancements in multi-omics studies have revealed diverse classifications of SCLC that are featured by distinct characteristics and therapeutic vulnerabilities. With the accumulation of SCLC samples, different subtypes of SCLC and specific treatments for these subtypes were further explored. The identification of different molecular subtypes has opened up novel avenues for the treatment of SCLC; however, the inconsistent and uncertain classification of SCLC has hindered the translation from basic research to clinical applications. Therefore, a comprehensives review is essential to conclude these emerging subtypes and related drugs targeting specific therapeutic vulnerabilities within abnormal signaling pathways. In this current review, we summarized the epidemiology, risk factors, mutation characteristics of and classification, related molecular pathways and treatments for SCLC. We hope that this review will facilitate the translation of molecular subtyping of SCLC from theory to clinical application.

Identification of effective diagnostic genes and immune cell infiltration characteristics in small cell lung cancer by integrating bioinformatics analysis and machine learning algorithms

OBJECTIVES

To identify potential diagnostic markers for small cell lung cancer (SCLC) and investigate the correlation with immune cell infiltration.

METHODS

GSE149507 and GSE6044 were used as the training group, while GSE108055 served as validation group A and GSE73160 served as validation group B. Differentially expressed genes (DEGs) were identified and analyzed for functional enrichment. Machine learning (ML) was used to identify candidate diagnostic genes for SCLC. The area under the receiver operating characteristic curves was applied to assess diagnostic efficacy. Immune cell infiltration analyses were carried out.

RESULTS

There were 181 DEGs identified. The gene ontology analysis showed that DEGs were enriched in 455 functional annotations, some of which were associated with immunity. The kyoto encyclopedia of genes and genomes analysis revealed that there were 9 signaling pathways enriched. The disease ontology analysis indicated that DEGs were related to 116 diseases. The gene set enrichment analysis results displayed multiple items closely related to immunity. ZWINT and NRCAM were screened using ML and further validated as diagnostic genes. Significant differences were observed in SCLC with normal lung tissue samples among immune cell infiltration characteristics. Strong associations were found between the diagnostic genes and immune cell infiltration.

CONCLUSION

This study identified 2 diagnostic genes, ZWINT and NRCAM, that were related to immune cell infiltration by integrating bioinformatics analysis and ML algorithms. These genes could serve as potential diagnostic biomarkers and provide possible molecular targets for immunotherapy in SCLC.

BRCA1 orchestrates the response to BI-2536 and its combination with alisertib in MYC-driven small cell lung cancer

PLK1 is currently at the forefront of mitotic research and has emerged as a potential target for small cell lung cancer (SCLC) therapy. However, the factors influencing the efficacy of PLK1 inhibitors remain unclear. Herein, BRCA1 was identified as a key factor affecting the response of SCLC cells to BI-2536. Targeting AURKA with alisertib, at a non-toxic concentration, reduced the BI-2536-induced accumulation of BRCA1 and RAD51, leading to DNA repair defects and mitotic cell death in SCLC cells. In vivo experiments confirmed that combining BI-2536 with alisertib impaired DNA repair capacity and significantly delayed tumor growth. Additionally, GSEA analysis and loss- and gain-of-function assays demonstrated that MYC/MYCN signaling is crucial for determining the sensitivity of SCLC cells to BI-2536 and its combination with alisertib. The study further revealed a positive correlation between RAD51 expression and PLK1/AURKA expression, and a negative correlation with the IC50 values of BI-2536. Manipulating RAD51 expression significantly influenced the efficacy of BI-2536 and restored the MYC/MYCN-induced enhancement of BI-2536 sensitivity in SCLC cells. Our findings indicate that the BRCA1 and MYC/MYCN-RAD51 axes govern the response of small cell lung cancer to BI-2536 and its combination with alisertib. This study propose the combined use of BI-2536 and alisertib as a novel therapeutic strategy for the treatment of SCLC patients with MYC/MYCN activation.

Distinct Regulation of ASCL1 by the Cell Cycle and Chemotherapy in Small Cell Lung Cancer

Small cell lung cancer (SCLC) is an aggressive and lethal malignancy. Achaete-scute homolog 1 (ASCL1) is essential for the initiation of SCLC in mice and the development of pulmonary neuroendocrine cells (PNEC), which are the major cells of origin for SCLC. However, the regulatory mechanism of ASCL1 in SCLC remains elusive. Here, we found that ASCL1 expression gradually increases as the tumors grow in a mouse SCLC model, and is regulated by the cell cycle. Mechanistically, CDK2-CyclinA2 complex phosphorylates ASCL1, which results in increased proteasome-mediated ASCL1 protein degradation by E3 ubiquitin ligase HUWE1 during mitosis. TCF3 promotes the multisite phosphorylation of ASCL1 through the CDK2-CyclinA2 complex and the interaction between ASCL1 and TCF3 protects ASCL1 from degradation. The dissociation of TCF3 from ASCL1 during mitosis accelerates the degradation of ASCL1. In addition, chemotherapy drugs greatly reduce the transcription of ASCL1 in SCLC cells. Depletion of ASCL1 sensitizes SCLC cells to chemotherapy drugs. Together, our study demonstrates that ASCL1 is a cell-cycle-regulated protein and provides a theoretical basis for applying cell-cycle-related antitumor drugs in SCLC treatment. Implications:Our study revealed a novel regulatory mechanism of ASCL1 by cell cycle and chemotherapy drugs in SCLC. Treating patients with SCLC with a combination of ASCL1-targeting therapy and chemotherapy drugs could potentially be beneficial.

Patterns and prognostic values of programmed cell death-ligand 1 expression and CD8 + T-cell infiltration in small cell carcinoma of the esophagus: a retrospective analysis of 34 years of National Cancer Center data in China

BACKGROUND

Small cell carcinoma of the esophagus (SCCE) is an extremely rare and highly aggressive neuroendocrine malignancy with a strikingly poor prognosis. Given the great clinical successes of checkpoint immunotherapies, we explored the expression profile and clinical significance of programmed cell death-ligand 1 (PD-L1) and CD8 + T cell in SCCE for the first time.

MATERIALS AND METHODS

Tumor-infiltrating immune cells (TIICs) and tumor cells in postoperative, whole tumor sections from 147 SCCE patients were stained for PD-LI expression. We also evaluated each patient's Combined Positive Score (CPS). Multiplex immunofluorescence staining (CD3, CD20, CD68, and PD-L1) was introduced to clarify the location of PD-L1. CD8 density was analyzed by digital imaging and analysis of entire slides. Clinical outcomes were tested for correlations with both PD-L1 expression and CD8 density.

RESULTS

No patients had PD-L1 expressed in their tumor cells. PD-L1 + expression in TIICs was detected in 65 patients (44.2%) and 42 (28.6%) exhibited CPS positivity. Multiplex immunofluorescence staining demonstrated that most of the PD-L1 was expressed on the CD68 + monocytes/macrophages. PD-L1 expression in the TIICs and CPS was found to be correlated with paraffin block age, tumor length, macroscopic type, T stage, and increased overall survival (OS). Expression of PD-L1 in TIICs showed significantly prolonged relapse-free survival (RFS). Increasing CD8 densities were associated with increased PD-L1 expression ( Ptrend <0.0001). Multivariate regression confirmed that PD-L1 in TIICs and CD8 states were independent predictors of OS, and CD8 status were found to be independently predictive of RFS. A stratification based on PD-L1 and CD8 status was also significantly associated with both OS and RFS.

CONCLUSION

Expression of PD-L1 was only detected in TIICs from approximately half of the patients with SCCEs. In SCCEs, PD-L1 and CD8 status are novel prognostic biomarkers and may inform the implementation of risk-related therapeutic strategies. SCCEs with higher CD8 infiltration also had higher expression of PD-L1, suggesting the development of resistance against adaptive immunity. These findings support the assertion that PD-L1/programmed cell death 1 inhibitors should be investigated in this rare malignancy.

Long-term, 13-year survival after immune cell therapy combined with chemotherapy for extensive-stage small-cell lung cancer: a case report

While the incidence of small-cell lung cancer is low, it has a poor prognosis. Patients with extensive small-cell lung cancer account for about 70% of all cases of small-cell lung cancer, with a median overall survival duration of 8-13 months and a 5-year overall survival rate of only 1%-5%. Herein, we report small-cell lung cancer diagnosed by bronchoscopic biopsy in an adult male patient in 2011. The patient had a clinical stage of cT2N2M1 and stage IV disease (i.e., extensive small-cell lung cancer). Still, he survived for 13 years through a combination of chemotherapy, radiotherapy, and cytokine-induced killer (CIK) immunocell thera. Comprehensive tumor markers, lymphocyte subsets, and lung CT images were obtained through long-term follow-up. After 12 cycles of chemotherapy (CE/IP regimen) and 5940cgy/33f radiotherapy, we found that the patient was in an immunosuppressive state, so the patient was given CIK cell therapy combined with chemotherapy. After 2 years of immunocell-combined chemotherapy, there were no significant changes in the primary lesion or other adverse events. In the 13 years since the patient's initial diagnosis, we monitored the changes in the patient's indicators such as CEA, NSE, CD4/CD8 ratio, and CD3+CD4+ lymphocytes, suggesting that these may be the factors worth evaluating regarding the patient's immune status and the effectiveness of combination therapy. In this case, CIK cell immunotherapy combined with chemotherapy was applied to control tumor progression. With a good prognosis, we concluded that CIK cell immunotherapy combined with chemotherapy can prolong patient survival in cases of extensive small-cell lung cancer, and the advantages of combined therapy are reflected in improving the body's immune capacity and enhancing the killing effect of immune cells.

The predictive value of delta-like3 and serum NSE in evaluating chemotherapy response and prognosis in patients with advanced small cell lung carcinoma: An observational study

Lung cancer is one of the most malignant tumors with fastest morbidity and mortality. Small cell lung cancer (SCLC) is the most malignant pathological type of lung cancer with early metastasis and poor prognosis. At present, there is a lack of effective indicators to predict prognosis of SCLC patients. Delta-like 3 protein (DLL3) is selectively expressed on the surface of SCLC and is involved in proliferation and invasion. Neuron-specific enolase (NSE) is an enolase isoenzyme that is generally regarded as a biomarker for SCLC and may correlate with stage of SCLC, prognosis and chemotherapy response. NSE can be influenced by different types of factors. To explore the associations between expression levels of DLL3 in tumor tissues with platinum/etoposide chemotherapy response, and assess the prognostic values of DLL3, NSE and other potential prognostic factors in advanced SCLC patients were herein studied. Ninety-seven patients diagnosed with SCLC in Zhongda Hospital from 2014 to 2020 were enrolled in the study. Serum NSE levels were tested using ELISA methods before any treatment. The expression of DLL3 in tumor tissue was detected by Immunohistochemistry (IHC). We investigated the relationship of DLL3 expression with chemotherapy and survival. Progression free survival (PFS) and overall survival (OS) were estimated by the Kaplan-Meier method. Multivariate Cox-proportional hazard regression was used to identify predictors of PFS and OS. DLL3 was detected in 84.5% (82/97) of all patients' tumor samples by IHC, mainly located on the surface of SCLC cells. Lower DLL3 expression was associated with longer PFS and better chemotherapy response. OS had no significant differences. Multivariate analysis by Cox Hazard model showed that, high DLL3 expression and maximum tumor size >5 cm were independent risk factors for PFS, where NSE < 35 ng/mL and age < 70 were independent prognostic factors for OS. Early stage was independent prognostic factors for PFS and OS (P < .05 log-rank). DLL3 was expressed in the most of SCLCs. DLL3 expression level in the tumor and NSE level in the serum may be useful biomarkers to predict the prognosis of SCLC. DLL3 may be a potential therapeutic target for SCLC in the future.

Serum albumin and derived neutrophil-to-lymphocyte ratio are potential predictive biomarkers for immune checkpoint inhibitors in small cell lung cancer

Background

Immune checkpoint inhibitors (ICIs) have reshaped the treatment landscape of small cell lung cancer (SCLC), but only a minority of patients benefit from this therapy. Therefore, it is critical to identify potential risk factors that could predict the efficacy of ICI treatment in SCLC patients and identify patient subgroups who may benefit the most from ICI therapy.

Methods

Our study included a total of 183 SCLC patients who had received at least one dose of ICI treatment. We utilized both logistic regression and Cox proportional hazard regression to evaluate whether various patient clinical factors and serum biomarkers could serve as predictors of patient response to treatment and overall survival (OS) during ICI therapy.

Results

Logistic regression showed that patients with a history of surgery (p=0.003, OR 9.06, 95% CI: (2.17, 37.9)) and no metastasis (p=0.008, OR 7.82, 95% CI: (1.73, 35.4)) exhibited a higher odds of response to ICI treatment. Cox regression analyses demonstrated that pretreatment blood albumin (p=0.003, HR 1.72, 95% CI: (1.21, 2.45)) and derived neutrophil to lymphocyte ratio (dNLR) (p=0.003, HR 1.71, 95% CI: (1.20-2.44)) were independent predictors for OS in SCLC patients. By establishing a pre-treatment prognostic scoring system based on baseline albumin and dNLR, we found that patients with high albumin and low dNLR exhibited a significantly better prognosis than those with low albumin and high dNLR in both the full (P<.0001, HR 0.33, 95% CI: 0.20-0.55) and the metastatic cohort (P<.0001, HR 0.28, 95% CI: 0.15-0.51). The better prognostic group also had younger age, higher BMI and lower systemic inflammatory biomarker values than the unfavorable group (P<.0001).

Conclusion

Our data reveals the significant role of metastasis status and treatment history in predicting the initial response of SCLC patients to ICI treatment. However, baseline serum albumin and dNLR provide a more precise prognostic prediction for patient OS. The scoring system based on albumin and dNLR enhances the ability to stratify patient prognosis and holds the potential to guide clinical decision-making for SCLC patients undergoing ICI therapy.

EHMT2-mediated transcriptional reprogramming drives neuroendocrine transformation in non-small cell lung cancer

The transformation of lung adenocarcinoma to small cell lung cancer (SCLC) is a recognized resistance mechanism and a hindrance to therapies using epidermal growth factor receptor tyrosine kinase inhibitors (TKIs). The paucity of pretranslational/posttranslational clinical samples limits the deeper understanding of resistance mechanisms and the exploration of effective therapeutic strategies. Here, we developed preclinical neuroendocrine (NE) transformation models. Next, we identified a transcriptional reprogramming mechanism that drives resistance to erlotinib in NE transformation cell lines and cell-derived xenograft mice. We observed the enhanced expression of genes involved in the EHMT2 and WNT/β-catenin pathways. In addition, we demonstrated that EHMT2 increases methylation of the SFRP1 promoter region to reduce SFRP1 expression, followed by activation of the WNT/β-catenin pathway and TKI-mediated NE transformation. Notably, the similar expression alterations of EHMT2 and SFRP1 were observed in transformed SCLC samples obtained from clinical patients. Importantly, suppression of EHMT2 with selective inhibitors restored the sensitivity of NE transformation cell lines to erlotinib and delayed resistance in cell-derived xenograft mice. We identify a transcriptional reprogramming process in NE transformation and provide a potential therapeutic target for overcoming resistance to erlotinib.

CD3, CD8, IFN-γ, tumor and stroma inflammatory cells as prognostic indicators for surgically resected SCLC: evidences from a 10-year retrospective study and immunohistochemical analysis

Current clinical guidelines limit surgical intervention to patients with cT1-2N0M0 small cell lung cancer (SCLC). Our objective was to reassess the role of surgery in SCLC management, and explore novel prognostic indicators for surgically resected SCLC. We reviewed all patients diagnosed with SCLC from January 2011 to April 2021 in our institution. Survival analysis was conducted using the Kaplan-Meier method, and independent prognostic factors were assessed through the Cox proportional hazard model. In addition, immunohistochemistry (IHC) staining was performed to evaluate the predictive value of selected indicators in the prognosis of surgically resected SCLC patients. In the study, 177 SCLC patients undergoing surgical resection were ultimately included. Both univariate and multivariate Cox analysis revealed that incomplete postoperative adjuvant therapy emerged as an independent risk factor for adverse prognosis (p < 0.001, HR 2.96). Survival analysis revealed significantly superior survival among pN0-1 patients compared to pN2 patients (p < 0.0001). No significant difference in postoperative survival was observed between pN1 and pN0 patients (p = 0.062). Patients with postoperative stable disease (SD) exhibited lower levels of tumor inflammatory cells (TIC) (p = 0.0047) and IFN-γ expression in both area and intensity (p < 0.0001 and 0.0091, respectively) compared to those with postoperative progressive disease (PD). Conversely, patients with postoperative SD showed elevated levels of stromal inflammatory cells (SIC) (p = 0.0453) and increased counts of CD3+ and CD8+ cells (p = 0.0262 and 0.0330, respectively). Survival analysis indicated that high levels of SIC, along with low levels of IFN-γ+ cell area within tumor tissue, may correlate positively with improved prognosis in surgically resected SCLC (p = 0.017 and 0.012, respectively). In conclusion, the present study revealed that the patients with pT1-2N1M0 staging were a potential subgroup of SCLC patients who may benefit from surgery. Complete postoperative adjuvant therapy remains an independent factor promoting a better prognosis for SCLC patients undergoing surgical resection. Moreover, CD3, CD8, IFN-γ, TIC, and SIC may serve as potential indicators for predicting the prognosis of surgically resected SCLC.

Achieving long-term survival in extensive-stage SCLC: a case report and mini literature review

Managing extensive-stage SCLC (ES-SCLC) has long been challenging for clinicians and oncologists due to its aggressive nature and poor prognosis. We report a case of a 41-year-old female with ES-SCLC who survived for six years, defying the disease's typically poor prognosis. Through a heavy treatment strategy involving chemotherapy, targeted therapy, and immunotherapy, the patient experienced robust responses and avoided distant metastasis, including brain involvement. The long-term survival case in SCLC highlights the need for further research into personalized strategies and prognostic biomarkers. This case holds significant value for both clinicians and researchers as it challenges the conventional strategies for ES-SCLC and sets the stage for future evidence-based studies aimed at extending survival in SCLC.

Efficacy and safety of novel immune checkpoint inhibitor-based combinations versus chemotherapy as first-line treatment for patients with extensive-stage small cell lung cancer: A network meta-analysis

BACKGROUND

Patients with extensive-stage small cell lung cancer (ES-SCLC) have an exceptionally poor prognosis and immune checkpoint inhibitors (ICIs) combined with etoposide-platinum is recommended as standard first-line therapy. However, which combination pattern is the best still remains unknown. This network meta-analysis was performed to compare the efficacy and safety of currently available patterns including an antiangiogenic agent containing regimen and probed into the most appropriate therapy for patients.

METHODS

Hazard ratios (HRs) and odds ratios (ORs) were generated using R software. The outcomes of overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and adverse events of grade 3 or higher (grade ≥ 3 adverse events [AEs]) were analyzed.

RESULTS

A total of 10 randomized controlled trials (RCTs) involving 5544 patients were included for analysis. Drug combination patterns included adebrelimab, atezolizumab, durvalumab, durvalumab plus tremelimumab, ipilimumab, pembrolizumab, serplulimab, benmelstobart plus anlotinib, tislelizumab, tiragolumab plus atezolizumab and toripalimab in combination with chemotherapy. The novel antiangiogenic agent containing regimen benmelstobart + anlotinib + chemotherapy showed the highest possibility to present the best PFS and OS versus chemotherapy. Compared with ICI plus chemotherapy, it also achieved significantly better PFS and presented a tendency of OS benefit. As for safety and toxicity, patients treated with benmelstobart + anlotinib + chemotherapy and durvalumab + tremelimumab + chemotherapy suffered a higher likelihood of more grade ≥ 3 AEs without unexpected AEs.

CONCLUSION

PD-1/PD-L1 inhibitors-based combinations are associated with significant improvement in both PFS and OS for treatment-naïve ES-SCLC patients. Benmelstobart plus anlotinib with chemotherapy (CT) yielded better survival benefit versus CT alone or other ICIs + CT with caution for more adverse effects along with the addition of an antiangiogenic agent.

WITHDRAWN: Supinoxin blocks Small Cell Lung Cancer Progression by Inhibiting Mitochondrial Respiration through the RNA Helicase DDX5

The authors have requested that this preprint be removed from Research Square.

Phosphorylation of AGO2 by TBK1 Promotes the Formation of Oncogenic miRISC in NSCLC

Non-small-cell lung cancer (NSCLC) is a highly lethal tumor that often develops resistance to targeted therapy. It is shown that Tank-binding kinase 1 (TBK1) phosphorylates AGO2 at S417 (pS417-AGO2), which promotes NSCLC progression by increasing the formation of microRNA-induced silencing complex (miRISC). High levels of pS417-AGO2 in clinical NSCLC specimens are positively associated with poor prognosis. Interestingly, the treatment with EGFR inhibitor Gefitinib can significantly induce pS417-AGO2, thereby increasing the formation and activity of oncogenic miRISC, which may contribute to NSCLC resistance to Gefitinib. Based on these, two therapeutic strategies is developed. One is jointly to antagonize multiple oncogenic miRNAs highly expressed in NSCLC and use TBK1 inhibitor Amlexanox reducing the formation of oncogenic miRISC. Another approach is to combine Gefitinib with Amlexanox to inhibit the progression of Gefitinib-resistant NSCLC. This findings reveal a novel mechanism of oncogenic miRISC regulation by TBK1-mediated pS417-AGO2 and suggest potential therapeutic approaches for NSCLC.

GPNMB Expression Associates with Inferior Prognosis in Patients with Small Cell Lung Cancer

Purpose: Small cell lung cancer (SCLC) is widely recognized for its propensity for early and frequent metastases, which contribute to its status as a refractory malignancy. While the high expression of GPNMB in SCLC is well-documented, the precise correlation between GPNMB expression and the prognosis of SCLC remains undetermined. Methods: HTG Edge-seq was used to screen the differential gene expression between primary SCLC lesions and paired metastatic lymph nodes (LN). The plasma concentration of GPNMB was measured using enzyme-linked immunosorbent assay (ELISA). The relationship between GPNMB concentration and clinical characteristics, as well as overall survival (OS) was assessed. One-to-one propensity score matching (PSM) was performed to reduce bias from confounding factors between groups. The invasive, migratory, proliferative, and apoptotic abilities of SCLC cells were evaluated using migration and matrigel invasion assays, CCK8 assay and flow cytometry respectively. Results: GPNMB exhibited a significant up-regulation in LN compared to primary SCLC lesions as determined by HTG Edge-seq. Furthermore, patients with extensive disease demonstrated a significantly elevated plasma GPNMB concentration compared to those with local disease (P = 0.043). Additionally, patients with a high baseline plasma GPNMB level exhibited a shorter OS (10.32 vs. 16.10 months, P = 0.0299). Following PSM analysis, the statistical significance of the difference between the two groups persisted (9.43 vs. 15.27 months, P = 0.0146). Notably, both univariate and multivariate analyses confirmed that higher expression of GPNMB served as an independent biomarker for OS before PSM (P = 0.033, HR = 2.304) and after PSM (P = 0.003, HR = 6.190). Additionally, our study revealed that the inhibition of GPNMB expression through the use of siRNA effectively diminished the metastatic and proliferative capabilities of SCLC. Furthermore, this inhibition resulted in an enhanced ability to induce apoptosis. Conclusions: In light of our findings, it can be inferred that the expression of GPNMB is linked to metastasis and an unfavorable prognosis, thus suggesting its potential as a novel therapeutic target in the treatment of SCLC.

Expression patterns and clinical implications of PDL1 and DLL3 biomarkers in small cell lung cancer retrospectively studied: Insights for therapeutic strategies and survival prediction

Lung cancer is a leading cause of cancer-related deaths globally, includes small cell lung cancer (SCLC), characterized by its aggressive nature and advanced disease at diagnosis. However, the identification of reliable biomarkers for SCLC has proven challenging, as no consistent predictive biomarker has been established. Nonetheless, certain tumor-associated antigens, including programmed death-ligand 1 (PDL1) and Delta-Like Ligand 3 (DLL3), show promise for targeted antibody-based immunotherapy. To ensure optimal patient selection, it remains crucial to comprehend the relationship between PDL1 and DLL3 expression and clinicopathological characteristics in SCLC. In this study, we investigated the expression patterns of PDL1 and DLL3 biomarkers in endobronchial samples from 44 SCLC patients, examining their association with clinical characteristics and survival. High PDL1 expression (>1%) was observed in 14% of patients, while the majority the SCLC patients (73%) exhibited high DLL3 expression (>75%). Notably, we found a positive correlation between high PDL1 expression (>1%) and overall survival. However, we did not observe any significant differences in the biomarkers expression concerning age, sex, disease status, smoking status, or distant metastases. Further subgroup analysis revealed that a high co-expression of both PDL1 (>1%) and DLL3 (100%) antigens was associated with improved overall survival. This suggests that SCLC expressing PDL1 and DLL3 antigens may exhibit increased sensitivity to therapy, indicating their potential as therapeutic targets. Thus, our findings provide novel insights into the simultaneous evaluation of PDL1 and DLL3 biomarkers in SCLC patients. These insights have significant clinical implications for therapeutic strategies, survival prediction, and development of combination immunotherapies.

Immune heterogeneity in small-cell lung cancer and vulnerability to immune checkpoint blockade

Atezolizumab (anti-PD-L1), combined with carboplatin and etoposide (CE), is now a standard of care for extensive-stage small-cell lung cancer (ES-SCLC). A clearer understanding of therapeutically relevant SCLC subsets could identify rational combination strategies and improve outcomes. We conduct transcriptomic analyses and non-negative matrix factorization on 271 pre-treatment patient tumor samples from IMpower133 and identify four subsets with general concordance to previously reported SCLC subtypes (SCLC-A, -N, -P, and -I). Deeper investigation into the immune heterogeneity uncovers two subsets with differing neuroendocrine (NE) versus non-neuroendocrine (non-NE) phenotypes, demonstrating immune cell infiltration hallmarks. The NE tumors with low tumor-associated macrophage (TAM) but high T-effector signals demonstrate longer overall survival with PD-L1 blockade and CE versus CE alone than non-NE tumors with high TAM and high T-effector signal. Our study offers a clinically relevant approach to discriminate SCLC patients likely benefitting most from immunotherapies and highlights the complex mechanisms underlying immunotherapy responses.

Expression levels of key immune indicators and immune checkpoints in manganese-exposed rats

Manganese is essential trace elements, to participate in the body a variety of biochemical reactions, has important physiological functions, such as stimulate the immune cell proliferation, strengthen the cellular immunity, etc. However, excessive manganese exposure can cause damage to multiple systems of the body.The immune system is extremely vulnerable to external toxicants, however manganese research on the immune system are inadequate and biomarkers are lacking. Therefore, here we applied a manganese-exposed rat model to make preliminary observations on the immunotoxic effects of manganese. We found that manganese exposure inhibited humoral immune function in rats by decreasing peripheral blood IgG (ImmunoglobulinG, IgG), IgM (ImmunoglobulinM, IgM) and complement C3 levels; It also regulates rat cellular immune activity by influencing peripheral blood, spleen, and thymus T cell numbers and immune organ ICs (Immune Checkpoints, ICs) and cytokine expression. Furthermore, it was revealed that the impact of manganese exposure on the immune function of rats exhibited a correlation with both the dosage and duration of exposure. Notably, prolonged exposure to high doses of manganese had the most pronounced influence on rat immune function, primarily manifesting as immunosuppression.The above findings suggest that manganese exposure leads to impaired immune function and related changes in immune indicators, or may provide clues for the discovery of its biomarkers.

Functional Characterisation of the ATOH1 Molecular Subtype Indicates a Pro-Metastatic Role in Small Cell Lung Cancer

Molecular subtypes of Small Cell Lung Cancer (SCLC) have been described based on differential expression of transcription factors (TFs) ASCL1, NEUROD1, POU2F3 and immune-related genes. We previously reported an additional subtype based on expression of the neurogenic TF ATOH1 within our SCLC Circulating tumour cell-Derived eXplant (CDX) model biobank. Here we show that ATOH1 protein was detected in 7/81 preclinical models and 16/102 clinical samples of SCLC. In CDX models, ATOH1 directly regulated neurogenesis and differentiation programs consistent with roles in normal tissues. In ex vivo cultures of ATOH1-positive CDX, ATOH1 was required for cell survival. In vivo, ATOH1 depletion slowed tumour growth and suppressed liver metastasis. Our data validate ATOH1 as a bona fide oncogenic driver of SCLC with tumour cell survival and pro-metastatic functions. Further investigation to explore ATOH1 driven vulnerabilities for targeted treatment with predictive biomarkers is warranted.

Biomarker-driven phase 2 umbrella trial: Clinical efficacy of olaparib monotherapy and combination with ceralasertib (AZD6738) in small cell lung cancer

BACKGROUND

Based on a high incidence of genomic alteration in the cell cycle and DNA damage and response (DDR)-related pathways in small cell lung cancer (SCLC), the clinical efficacy of the DDR-targeting agent olaparib (PARP inhibitor) as monotherapy and in combination with ceralasertib (ATR inhibitor) in relapsed or refractory SCLC was evaluated.

METHODS

As part of a phase 2 biomarker driven umbrella study, patients with SCLC and predefined DDR gene alterations who failed to benefit from prior platinum-based regimens were allocated to the olaparib monotherapy arm and nonbiomarker-selected patients were allocated to the olaparib and ceralasertib combination arm.

RESULTS

In the olaparib monotherapy arm (n = 15), the objective response rate was 6.7% (one partial response), and the disease control rate was 33.3%, including three patients with stable disease. The median progression-free survival was 1.3 months (95% CI, 1.2-NA). In the combination arm (n = 26), the objective response rate and disease control rate were 3.8% and 42.3%, respectively, with one partial response and 10 patients with stable disease. The median progression-free survival was 2.8 months (95% CI, 1.8-5.4). Treatment was generally well tolerated except for one fatal case of neutropenic fever in the combination arm.

CONCLUSIONS

Targeting DDR pathways with olaparib as a single agent or in combination with ceralasertib did not meet the predefined efficacy end point. However, disease stabilization was more evident in the combination arm. Further investigation of the combination of olaparib in SCLC should be performed with diverse combinations and patient selection strategies to maximize efficacy.

Clinical utility of immunohistochemical subtyping in patients with small cell lung cancer

OBJECTIVES

Molecular subtyping of small cell lung cancer (SCLC) tumors based on the expression of four transcription factors (ASCL1, NEUROD1, POU2F3, and YAP1) using immunohistochemical (IHC) staining has recently emerged as a proposed approach. This study was aimed to examine this subtyping method in Asian patients with SCLC and investigate its correlation with treatment efficacy.

MATERIALS AND METHODS

Seventy-two tumor samples from patients with SCLC, including de novo cases and those transformed from EGFR-mutant tumors, were analyzed. IHC staining was used to measure the expression of the four transcription factors and conventional SCLC markers. Subtypes were defined based on relative expression levels. The treatment response and outcome of patients receiving immune checkpoint inhibitors and chemotherapy were also reviewed.

RESULTS

ASCL1 was the most common subtype, observed in 55.2 % of the samples, followed by NEUROD1 (26.9 %) and POU2F3 (9 %). No tumor exhibited predominant YAP1 positivity, while 41.8 % of the samples demonstrated positivity for two subtype markers. Approximately 50 % of the patients experienced a subtype switch after disease progression. Patients with the ASCL1/NEUROD1 (SCLC-A/N) subtype had similar progression-free survival (PFS) compared to non-SCLC-A/N patients after treatment with immune checkpoint inhibitors plus chemotherapy. Transformed SCLC patients had significantly worse PFS than de novo SCLC patients after chemoimmunotherapy. (2.1 vs. 5.4 months, P = 0.023) CONCLUSIONS: This study revealed the challenges associated with using IHC alone for molecular subtyping, highlighting the frequent co-expression of subtypes and temporal changes following treatment. Further research is warranted to explore the prognostic and therapeutic implications of IHC subtyping in patients with SCLC.

The inhibitory effect of apatinib on different small cell lung cancer cells and in lung cancer-bearing mice and patients

PURPOSE

To observe the inhibitory effect of the small molecule tyrosine kinase inhibitor apatinib on small cell lung cancer in vitro and vivo.

MATERIAL AND METHODS

Three small lung cancer cells were selected CCK-8 and monoclonal assay was used to determine the effect of apatinib on proliferation. The effects on cell cycle and apoptosis were detected by flow cytometry and TUNEL. We observed the inhibitory effect of different doses of apatinib on xenograft tumor. The efficacy and safety of apatinib in 20 patients with advanced small cell lung cancer were observed.

RESULTS

For small cell lung cancer with high expression of VEGFR2, apatinib has a significant inhibitory effect both in vitro and in vivo. It can play an inhibitory role by promoting apoptosis and cell cycle arrest pathways. For small cell lung cancer with low expression of VEGFR, the inhibitory effect on cells in vitro was not significant. It has certain inhibitory effect on nude mouse transplanted tumor and small cell lung cancer patients, but the effect is weaker than that of animal models and patients with small cell lung cancer cells with high expression of VEGFR2.

CONCLUSION

Apatinib has a significant inhibitory effect on small cell lung cancer with high expression of VEGFR2 and may be a treatment for small cell lung cancer patients.

Genetically-engineered mouse models of small cell lung cancer: the next generation

Small cell lung cancer (SCLC) remains the most fatal form of lung cancer, with patients in dire need of new and effective therapeutic approaches. Modeling SCLC in an immunocompetent host is essential for understanding SCLC pathogenesis and ultimately discovering and testing new experimental therapeutic strategies. Human SCLC is characterized by near universal genetic loss of the RB1 and TP53 tumor suppressor genes. Twenty years ago, the first genetically-engineered mouse model (GEMM) of SCLC was generated using conditional deletion of both Rb1 and Trp53 in the lungs of adult mice. Since then, several other GEMMs of SCLC have been developed coupling genomic alterations found in human SCLC with Rb1 and Trp53 deletion. Here we summarize how GEMMs of SCLC have contributed significantly to our understanding of the disease in the past two decades. We also review recent advances in modeling SCLC in mice that allow investigators to bypass limitations of the previous generation of GEMMs while studying new genes of interest in SCLC. In particular, CRISPR/Cas9-mediated somatic gene editing can accelerate how new genes of interest are functionally interrogated in SCLC tumorigenesis. Notably, the development of allograft models and precancerous precursor models from SCLC GEMMs provides complementary approaches to GEMMs to study tumor cell-immune microenvironment interactions and test new therapeutic strategies to enhance response to immunotherapy. Ultimately, the new generation of SCLC models can accelerate research and help develop new therapeutic strategies for SCLC.

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.

RNA-based Therapeutics: Past, Present and Future Prospects, Challenges in Cancer Treatment

It is becoming more and harder in today's climate to disregard the impact of cancer on social health. Even though a significant amount of money is spent annually on cancer research, it still ranks as the second leading cause of death worldwide. Additionally, only about half of the patients suffering from complex forms of cancer survive a year after receiving traditional cancer therapies. A method for silencing genes is called RNA interference (RNAi). Such a method is very effective in focusing on genes linked to cancer. Most gene products implicated in cancer have recently been used as RNA interference (RNAi) therapeutic targets. According to the findings from this research, RNAi application is necessary for today's cancer treatment to target functioning carcinogenic molecules and tumor resistance to chemotherapy and radiation. Proapoptotic and antiproliferative activity has been reported from previous research studies on cell culture systems, animal models, and clinical trials through the knockdown of gene products from RNAi technology. Numerous novel RNAi-based medications are now in the clinical trial stages thanks to the discovery of the RNAi mechanism and advancements in the area. In the future, genomic-based personalized medicines can be developed through this RNAi therapy. Hopefully, cancer sufferers will find this sort of therapy to be one of the most effective ones. Various kinds of RNA-based treatments, such as aptamers, small interfering RNAs, microRNAs, antisense oligonucleotides, and messenger RNA, are covered in broad terms in this study. We also present an overview of the RNA-based therapies that have received regulatory approval in the past or are now undergoing clinical studies.

Entinostat Enhances the Efficacy of Chemotherapy in Small Cell Lung Cancer Through S-phase Arrest and Decreased Base Excision Repair

PURPOSE

Acquired chemoresistance is a frequent event in small cell lung cancer (SCLC), one of the deadliest human malignancies. Histone deacetylase inhibitors (HDACi) have been shown to synergize with different chemotherapeutic agents including cisplatin. Accordingly, we aimed to investigate the dual targeting of HDAC inhibition and chemotherapy in SCLC.

EXPERIMENTAL DESIGN

The efficacy of HDACi and chemotherapy in SCLC was investigated both in vitro and in vivo. Synergistic drug interactions were calculated based on the HSA model (Combenefit software). Results from the proteomic analysis were confirmed via ICP-MS, cell-cycle analysis, and comet assays.

RESULTS

Single entinostat- or chemotherapy significantly reduced cell viability in human neuroendocrine SCLC cells. The combination of entinostat with either cisplatin, carboplatin, irinotecan, epirubicin, or etoposide led to strong synergy in a subset of resistant SCLC cells. Combination treatment with entinostat and cisplatin significantly decreased tumor growth in vivo. Proteomic analysis comparing the groups of SCLC cell lines with synergistic and additive response patterns indicated alterations in cell-cycle regulation and DNA damage repair. Cell-cycle analysis revealed that cells exhibiting synergistic drug responses displayed a shift from G1 to S-phase compared with cells showing additive features upon dual treatment. Comet assays demonstrated more DNA damage and decreased base excision repair in SCLC cells more responsive to combination therapy.

CONCLUSIONS

In this study, we decipher the molecular processes behind synergistic interactions between chemotherapy and HDAC inhibition. Moreover, we report novel mechanisms to overcome drug resistance in SCLC, which may be relevant to increasing therapeutic success.

Efficacy and safety of high-dose ilaprazole-amoxicillin dual therapy for Helicobacter pylori eradication: a prospective, single-center, randomized trial

Background: Until now, there have been no randomized controlled trials directly evaluating the efficacy of high-dose ilaprazole-amoxicillin dual therapy (HT) in comparison to other standard treatments for H. pylori (Helicobacter pylori) infection. This study aimed to compare the effectiveness and safety of HT with bismuth quadruple therapy (BQT) as an initial treatment for H. pylori. Methods: This single-center, prospective, randomized clinical controlled trial recruited 225 consecutive patients. They were assigned to either HT group (ilaprazole, 10 mg, twice daily; amoxicillin 1,000 mg, three times daily) or BQT group (compound bismuth aluminate granules, 2.6 g, three times daily; ilaprazole, 5 mg, twice daily; amoxicillin, 1,000 mg, twice daily; clarithromycin, 500 mg, twice daily) for 14 days. The 13C-urea breath test assessed eradication success 4 weeks after treatment. The primary outcome focused on the eradication rate, with secondary outcomes including safety and compliance. Results: From February 2023 to March 2023, 228 subjects were screened, and 225 were randomized. The HT and BQT groups showed eradication rates of 76.3% and 61.3% (p = 0.015) both by intention-to-treat (ITT) analysis and per-protocol (PP) analysis. HT was associated with fewer adverse events than BQT (27.2% vs. 81.8%, p = 0.002). The most commonly reported adverse events was bitter taste of mouth (3.5% vs. 60.4%, p < 0.001). There was no significant difference in compliance between the two groups (89.5% vs. 92.8%, p = 0.264). Conclusion: The 14-day HT treatment demonstrates better efficacy in H. pylori eradication treatment and improved safety and compliance compared to BQT. The results provide supporting evidence for 14-day HT can be potentially considered as a first-line regimen for empirical treatment. Clinical Trial Registration: https://www.chictr.org.cn/showproj.html?proj=186562, identifier ChiCTR2200066284.

Identification of Immune Subtypes and Candidate mRNA Vaccine Antigens in Small Cell Lung Cancer

BACKGROUND

Immune checkpoint inhibitors (ICIs) have demonstrated promising outcomes in small cell lung cancer (SCLC), but not all patients benefit from it. Thus, developing precise treatments for SCLC is a particularly urgent need. In our study, we constructed a novel phenotype for SCLC based on immune signatures.

METHODS

We clustered patients with SCLC hierarchically in 3 publicly available datasets according to the immune signatures. ESTIMATE and CIBERSORT algorithm were used to evaluate the components of the tumor microenvironment. Moreover, we identified potential mRNA vaccine antigens for patients with SCLC, and qRT-PCR were performed to detect the gene expression.

RESULTS

We identified 2 SCLC subtypes and named Immunity High (Immunity_H) and Immunity Low (Immunity_L). Meanwhile, we obtained generally consistent results by analyzing different datasets, suggesting that this classification was reliable. Immunity_H contained the higher number of immune cells and a better prognosis compared to Immunity_L. Gene-set enrichment analysis revealed that several immune-related pathways such as cytokine-cytokine receptor interaction, programmed cell death-Ligand 1 expression and programmed cell death-1 checkpoint pathway in cancer were hyperactivated in the Immunity_H. However, most of the pathways enriched in the Immunity_L were not associated with immunity. Furthermore, we identified 5 potential mRNA vaccine antigens of SCLC (NEK2, NOL4, RALYL, SH3GL2, and ZIC2), and they were expressed higher in Immunity_L, it indicated that Immunity_L maybe more suitable for tumor vaccine development.

CONCLUSIONS

SCLC can be divided into Immunity_H and Immunity_L subtypes. Immunity_H may be more suitable for treatment with ICIs. NEK2, NOL4, RALYL, SH3GL2, and ZIC2 may be act as potential antigens for SCLC.

Establishment and characterization of BMC-PDC-019: a novel patient-derived cell line of EGFR-mutant pulmonary adenocarcinoma transformed into small-cell lung cancer

Transformed small-cell lung cancer (tSCLC) from EGFR-mutant adenocarcinoma is a rare and aggressive form of lung cancer that can occur when the tumor develops resistance to EGFR targeted therapy and the cancer cells acquire additional genomic alterations that cause them to transform into SCLC. Treatment for tSCLC has not been established yet, and chemotherapy regimens for de novo SCLC are mostly recommended. However, these treatments showed disappointing outcome, and novel anti-cancer agents and immunological approaches are currently being developed. The patient-derived cell line is a critical tool for pre-clinical and translational research, but cell line models for tSCLC are not publicly available from cell banks. The aim of this study was to establish and characterize a novel cell line for tSCLC. Using a lymph-node biopsy tissue from a 58-year-old female patient, whose tumor was EGFR-mutant lung adenocarcinoma progressed on afatinib, we successfully established a cell line, named BMC-PDC-019. The tumor sample and cell line showed a typical expression of SCLC markers, such as CD56 and synaptophysin. The population doubling-time of BMC-PDC-019 cells was 48 h. We examined a range of proliferation-inhibiting effects of anti-cancer drugs currently used for de novo SCLC, using BMC-PDC-019 cells. We concluded that BMC-PDC-019 would be a useful tool for pre-clinical and translational research.

Treatment and survival of patients with small cell lung cancer and brain metastasis

PURPOSE

To elucidate treatment patterns and their outcomes in patients with small cell lung cancer (SCLC) and brain metastasis (BM).

METHODS

In this retrospective study, patients with SCLC and BM were stratified by treatment modality into three groups: those treated with systemic therapy only, those treated with stereotactic radiosurgery (SRS) and systemic therapy, and those treated with whole-brain radiotherapy (WBRT) and systemic therapy. The primary outcomes were overall survival (OS) and time to central nervous system progression (TTCP).

RESULTS

The analysis included 149 patients. After BM diagnosis, 48 patients (32.2%) received systemic therapy alone, 33 received SRS with systemic therapy, and 68 received WBRT with systemic therapy. The median OS and TTCP were 7.2 months and 8.7 months, respectively. Patients receiving WBRT with systemic therapy exhibited better intracranial control, but not better OS, than did the other patients. Key prognostic factors affecting OS were age, BM lesion count, chemotherapy, and immunotherapy. Notably, the Eastern Cooperative Oncology Group performance status and BM lesion count significantly influenced intracranial control in patients treated with SRS and systemic therapy.

CONCLUSION

Although WBRT combined with systemic therapy offer better intracranial control in patients with SCLC and BM, this approach is not superior to the other approaches in terms of OS benefits. Emerging systemic therapies, such as immunotherapy, may be used as alternative or adjunctive treatments for specific patient populations. Further studies are warranted to refine treatment selection.

A plasma miRNA-based classifier for small cell lung cancer diagnosis

Introduction

Small cell lung cancer (SCLC) is characterized by poor prognosis and challenging diagnosis. Screening in high-risk smokers results in a reduction in lung cancer mortality, however, screening efforts are primarily focused on non-small cell lung cancer (NSCLC). SCLC diagnosis and surveillance remain significant challenges. The aberrant expression of circulating microRNAs (miRNAs/miRs) is reported in many tumors and can provide insights into the pathogenesis of tumor development and progression. Here, we conducted a comprehensive assessment of circulating miRNAs in SCLC with a goal of developing a miRNA-based classifier to assist in SCLC diagnoses.

Methods

We profiled deregulated circulating cell-free miRNAs in the plasma of SCLC patients. We tested selected miRNAs on a training cohort and created a classifier by integrating miRNA expression and patients' clinical data. Finally, we applied the classifier on a validation dataset.

Results

We determined that miR-375-3p can discriminate between SCLC and NSCLC patients, and between SCLC and Squamous Cell Carcinoma patients. Moreover, we found that a model comprising miR-375-3p, miR-320b, and miR-144-3p can be integrated with race and age to distinguish metastatic SCLC from a control group.

Discussion

This study proposes a miRNA-based biomarker classifier for SCLC that considers clinical demographics with specific cut offs to inform SCLC diagnosis.

Risk factors of early mortality in patients with small cell lung cancer: a retrospective study in the SEER database

BACKGROUND

Small cell lung cancer (SCLC) is a highly aggressive neuroendocrine cancer with a high risk of early mortality (i.e., survival time less than 1 month). This study aimed to identify relevant risk factors and predict early mortality in SCLC patients.

METHODS

A total of 27,163 SCLC cases registered between 2010 and 2019 were extracted from the Surveillance, Epidemiology, and End Results (SEER) data. Significant independent risk factors were identified by univariate and multivariate logistic regression analyses. Nomograms for all-causes and cancer-specific early death were constructed and evaluated.

RESULTS

Age, sex, clinical stage, presence of metastasis (liver and lung), and absence of treatment (surgery, radiotherapy and chemotherapy) were identified for significant association with all-causes and cancer-specific early death. Nomograms based on these predictors exhibited high accuracy (area under ROC curve > 0.850) and potential clinical practicality in the prediction of early mortality.

CONCLUSION

We identified a set of factors associated with early mortality from SCLC and developed a clinically useful nomogram to predict high-risk patients. This nomogram could aid oncologists in the administration of individualized treatment regimens, potentially improving clinical outcomes of SCLC patients.