Expression In Small Cell Lung Cancer Research Articles

RHBDF1 modulates cisplatin sensitivity of small cell lung cancer through YAP1/Smad2 signaling pathway

Small cell lung cancer (SCLC) is a fatal tumor type that is prone to drug resistance. In our previous study, we showed that human rhomboid-5 homolog-1 (RHBDF1) was differentially expressed in 5 intrinsic cisplatin-resistant SCLC tissues compared with 5 intrinsic cisplatin-sensitive SCLC tissues by RNA sequencing, which intrigued us. We performed gain- and loss-of-function experiments to investigate RHBDF1 function, bioinformatics analysis, qRT-PCR, western blotting, and immunoprecipitation to elucidate the molecular mechanisms as well as detect RHBDF1 expression in SCLC by immunohistochemistry. We found that RHBDF1 knockdown promoted cell proliferation and cisplatin chemoresistance and inhibited apoptosis in vitro and in vivo. These effects could be reversed by overexpressing RHBDF1 in vitro. Mechanistically, RHBDF1 interacted with YAP1, which increased the phosphorylation of Smad2 and transported Smad2 to the nucleus. Among clinical specimens, the RHBDF1 was a low expression in SCLC and was associated with clinicopathological features and prognosis. We are the first to reveal that RHBDF1 inhibited cell proliferation and promoted cisplatin sensitivity in SCLC and elucidate a novel mechanism through RHBDF1/YAP1/Smad2 signaling pathway which played a crucial role in cisplatin chemosensitivity. Targeting this pathway can be a promising therapeutic strategy for chemotherapy resistance in SCLC.

Multidimensional analysis of B7 homolog 3 (B7-H3) RNA expression in small-cell lung cancer (SCLC) molecular subtypes.

8088 Background: SCLC is an aggressive cancer with a poor prognosis. B7-H3, a transmembrane protein showing low expression in normal tissues but overexpression in SCLC and other tumors, is a promising target for antibody–drug conjugates. We performed a multidimensional analysis of B7-H3/ CD276 expression in SCLC molecular subtypes (SCLC-A, -N, -P, and -I) and its relationship with expression of other immune-related genes. Methods: Clinical and molecular data for a cohort of patients (pts) with SCLC were derived from a real-world database (Caris Life Sciences, Irving, TX, USA). Tumor RNA expression was used to assign the SCLC molecular subtype derived from non-negative matrix factorization. Programmed death ligand-1 (PD-L1) protein expression was assessed by immunohistochemistry (IHC; antibody 22c3; positive cut-off: tumor proportion score >1%). Demographic, clinical, and molecular data were summarized by SCLC subtype or B7-H3 expression quartile (Q). Spearman’s r evaluated correlations between expression of B7-H3 and other immune-related genes/signatures. Results: The cohort included 1721 pts (52.5% female; 98.9% [434/439] smokers; median age, 67 years [range, 18–90+]). Across the subtypes, B7-H3 expression was high and remarkably consistent ( q>0.05; Table). Other biomarker genes, including DLL3 (q<0.05), had lower and more variable expression. Median (range) B7-H3 expression across all samples was 16.75 (0–68.2) transcripts per million (TPM). Across B7-H3 expression Qs, the proportion of PD-L1-positive pts by IHC was similar (Q1, 39.8%; Q2, 46.5%; Q3, 40.7%; Q4, 39.2%). Median (95% confidence interval) B7-H3 expression was similar between pts with prior immunotherapy ( n=24; 14.43 [11.64–21.17] TPM) and pts without ( n=208; 14.20 [13.00–15.91] TPM); treatment information was not available for the remaining samples in this cohort. B7-H3 expression was not strongly correlated with any other immune-related genes/signatures, although several had moderate correlation ( HAVCR2/ TIM3, r=0.59; PDCD1LG2/ PD-L2, r=0.56; M2 macrophages, r=0.56; CD86, r=0.56). Conclusions: In pts with SCLC, B7-H3 showed high and consistent expression across subgroups defined by molecular subtype or prior immunotherapy. The relative expression of B7-H3 was higher and less variable among molecular subtypes than for other key molecular targets in this tumor type, including DLL3. B7-H3 expression had limited association with PD-L1 expression, supporting a role as a distinct therapeutic target. [Table: see text]

The genomic, transcriptomic, and immunologic landscape of TEM8 (ANTXR1) in small-cell lung cancer (SCLC).

3128 Background: The TEM8 receptor (coded by ANTXR1) plays several roles in oncogenesis. Novel oncolytic therapies, such as the SVV-01 virus, uniquely bind this protein in tumor histologies such as small-cell lung cancer (SCLC). Emerging pre-clinical data suggest that TEM8-targeting therapies may convert immunologically “cold” tumor microenvironments (TME) into “hot” milieu with greater responses to immune checkpoint inhibitors (ICIs). Methods: NextGen sequencing of DNA (592 genes or whole exome)/RNA (whole transcriptome) was performed on SCLC ( N=1404) submitted to Caris Life Sciences (Phoenix, AZ). Mutations were defined as pathogenic SNVs/indels. ANTXR1H and ANTXR1L samples included those with >75th and <25th percentile expression, respectively. PD-L1 expression (22c3; Positive (+):TPS ³1%) was assessed by IHC. High tumor mutational burden (TMB-H) was defined as ≥10 mutations per MB. Cell infiltration in the TME was estimated by QuantiSEQ. Gene expression profiles were analyzed for transcriptional signatures predictive of response to immunotherapy (T cell-inflamed) and MAPK pathway activation score (MPAS). Real-world median overall survival (mOS) was assessed from insurance claims data, and Kaplan-Meier estimates were calculated for molecularly defined subpopulations of patients. Mann-Whitney U and X2/Fisher-Exact tests were applied where appropriate, with P-values adjusted for multiple comparisons ( p<0.05). Results: No pathogenic mutations were significantly associated with ANTXR1H vs L tumors ( p>0.05 for all), along with no differences in the prevalence of TMB-H (28.6% vs 36.3%, p=1) or PDL1+ (45.0%: vs 35.0%, p=1). However, a greater proportion of B cells (6.53 % vs 5.12%, p<0.001), M1 (1.63% vs 0.37%, p<0.001) and M2 macrophages (3.40% vs 1.50%, p<0.001) were observed in ANTXR1H TME, which were more frequently classified as T cell-inflamed compared to ANTXR1L TME (23% vs 5%, p<0.001). ANTXR1H tumors also had higher MPAS compared to ANTXR1L (1.36 vs -1.86 arbitrary units, p<0.001). There was no significant difference in mOS between ANTXR1H vs L tumors (12.2 vs 10.5 months, HR: 0.95, p=0.678). Conclusions: Increased B cell, M1 and M2 macrophage infiltrates, and increased prevalence of T-cell inflamed tumors in ANTXR1H TME suggest that these patients with SCLC may respond preferentially to ICI. A Phase 1 trial incorporating SVV-01 along with ICI is underway. Prospective investigation of molecular associations and clinical outcomes related to ANTXR1 expression in SCLC is warranted.

Clinical significance and prospective mechanism of increased CDKN2A expression in small cell lung cancer

BackgroundAlthough it has been shown that cyclin dependent kinase inhibitor 2A (CDKN2A) plays a significant role in a number of malignancies, its clinicopathological value and function in small cell lung cancer (SCLC) is unclear and warrants additional research.MethodsThe clinical significance of CDKN2A expression in SCLC was examined by multiple methods, including comprehensive integration of mRNA level by high throughput data, Kaplan–Meier survival analysis for prognostic value, and validation of its protein expression using in-house immunohistochemistry.ResultsThe expression of CDKN2A mRNA in 357 cases of SCLC was evidently higher than that in the control group (n = 525) combing the data from 20 research centers worldwide. The standardized mean difference (SMD) was 3.07, and the area under the curve (AUC) of summary receiver operating characteristic curve (sROC) was 0.97 for the overexpression of CDKN2A. ACC, COAD, KICH, KIRC, PCPG, PRAD, UCEC, UVM patients with higher CDKN2A expression had considerably worse overall survival rates than those with lower CDKN2A expression with the hazard ratio (HR) > 1.ConclusionCDKN2A upregulation extensively enhances the carcinogenesis and progression of SCLC.

Abstract LB_A22: Advancing personalized therapies for small cell lung cancer: Exploring HER2-targeting antibody-drug conjugates (ADCs) and SLFN11 biomarker insights

Abstract Background: Small-cell lung cancer (SCLC) is a highly aggressive malignancy constituting 15% of all lung cancers, with a 5-year survival rate of less than 7%. Our group has established four transcriptionally defined subtypes of SCLC, each with distinct cell surface targets (Gay et al, Cancer Cell 2021). Further, we identified SLFN11 (a putative DNA/RNA helicase) as a candidate biomarker of sensitivity to DNA-damaging agents, including topoisomerase I inhibitors. Despite these advances, SCLC is still treated clinically with a “one-size-fits-all” approach. Human epidermal growth factor receptor 2 (HER2/ERBB2) has been previously described in a subset of SCLCs and has been linked to poor prognosis. Notably, HER2-targeting antibody-drug conjugates (ADCs) like Trastuzumab Deruxtecan (T-DXd) (where the payload is a topoisomerase I inhibitor) have received FDA approval for various solid tumors, highlighting their therapeutic potential. Methods: We analyzed ERBB2 mRNA expression in publicly available patient datasets and profiled HER2 protein expression in cell lines and patient-derived xenograft models by flow cytometry and IHC. We then assessed the cytotoxicity of Trastuzumab Deruxtecan in a panel of cell lines representative of the heterogeneity of SCLC to test whether levels of HER2 and/or SLFN11 predicted response. Results: Analyses of HER2/ERBB2 in SCLC cell lines and patient-derived xenograft (PDX) models revealed an enrichment in the SCLC-POU2F3 (SCLC-P) subtype. HER2 expression was validated by IHC and flow cytometry in a subset of SCLC cell lines and PDX models. ERBB2 mRNA expression data was analyzed using publicly available SCLC patient datasets, where we uncovered high expression of ERBB2 in a subset of patient tumors. Consistent with this, single-cell RNA-Seq data revealed ERBB2 expression in POU2F3+ cells in tumors from patients with relapsed SCLC. As predicted, we found a strong correlation between the in vitro cytotoxicity of Trastuzumab Deruxtecan and both the level of surface HER2 expression and SLFN11 level. Importantly, the SCLC cell lines with the highest HER2 surface expression exhibited the lowest IC50 of Trastuzumab Deruxtecan, and the response was predicted by the presence of SLFN11. Conclusion: We demonstrate HER2/ERBB2 mRNA and protein expression in a subset of SCLC, with enrichment in the SCLC-P subtype. Further, the FDA-approved HER2-targeting ADC Trastuzumab Deruxtecan had significant cytotoxicity, correlating with expression of the surface target (HER2) as well as with SLFN11 (a candidate predictive biomarker for the topoisomerase inhibitor payload). These findings suggest the potential of tailoring HER2-targeting strategies based on HER2 and SLFN11 expression in SCLC as an effective and personalized approach for tackling SCLC. Citation Format: Ali H. Ibrahim, Bingnan Zhang, C. Allison Stewart, Alejandra Serrano, Luisa M. Solis, Wei-Lien Wang, Kavya Ramkumar, Robert J. Cardnell, Runsheng Wang, Alberto Duarte Jr, Lixia Diao, Yuanxin Xi, Jing Wang, Lauren A. Byers, Carl M. Gay. Advancing personalized therapies for small cell lung cancer: Exploring HER2-targeting antibody-drug conjugates (ADCs) and SLFN11 biomarker insights [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr LB_A22.

Tumor microenvironment-mediated immune profiles and efficacy of anti-PD-L1 antibody plus chemotherapy stratified by DLL3 expression in small-cell lung cancer.

Delta-like ligand 3 (DLL3) is a therapeutic target in small-cell lung cancer (SCLC). However, how DLL3 expression status affects the tumor microenvironment (TME) and clinical outcomes in SCLC remains unclear. This retrospective study included patients with postoperative limited-stage (LS)-SCLC and extensive-stage (ES)-SCLC treated with platinum and etoposide (PE) plus anti-programmed cell death ligand 1 (PD-L1) antibody. We investigated the relationship of DLL3 expression with TME, mutation status, tumor neoantigens, and immunochemotherapy. In the LS-SCLC cohort (n = 59), whole-exome sequencing revealed that DLL3High cases had significantly more neoantigens (P = 0.004) and a significantly higher rate of the signature SBS4 associated with smoking (P = 0.02) than DLL3Low cases. Transcriptome analysis in the LS-SCLC cohort revealed that DLL3High cases had significantly suppressed immune-related pathways and dendritic cell (DC) function. SCLC with DLL3High had significantly lower proportions of T cells, macrophages, and DCs than those with DLL3Low. In the ES-SCLC cohort (n = 30), the progression-free survival associated with PE plus anti-PD-L1 antibody was significantly worse in DLL3High cases than in DLL3Low cases (4.7 vs. 7.4 months, P = 0.01). Although SCLC with DLL3High had a higher neoantigen load, these tumors were resistant to immunochemotherapy due to suppressed tumor immunity by inhibiting antigen-presenting functions.

Long non-coding RNA MIR22HG inhibits the proliferation and migration, and promotes apoptosis by targeting microRNA-9-3p/ SOCS1 axis in small cell lung cancer cells.

This study aims to determine the role of long non-coding RNA (LncRNA) MIR22HG in small cell lung cancer (SCLC), and to explore its relevant mechanism. The expressions of genes and proteins in SCLC cells were examined applying qRT-PCR and western blot. Cell proliferation estimation was implemented utilizing cell counting kit-8 (CCK-8) and colony formation assays; the assessment of cell migration and invasion was operated employing Wound healing and Transwell; apoptosis evaluation was conducted adopting flow cytometric assay. Binding relationships was confirmed by luciferase reporter assay. Moreover, SCLC animal model was established to explore the role of MIR22HG in vivo. It was found that MIR22HG was declined and miR-9-3p was elevated in five SCLC cell lines (NCI-H446, NCI-H69, SHP-77, DMS79 and NCI-H345) in comparison with normal human bronchial epithelial cell line (NHBE). More interestingly, overexpression of MIR22HG resulted in decreased cell viability, declined colony formation, diminished capacities of cell migration and invasion in NCI-H446 and NCI-H345 cells but induced more apoptotic cells. However, these impacts were reversed by miR-9-3p upregulation. Meanwhile, MIR22HG could bind to miR-9-3p and negatively regulate its expression in SCLC. What's more, LncRNA MIR22HG overexpression was also testified to elevate SOCS1 via downregulating miR-9-3p expression. Furthermore, in vivo study further confirmed the role of MIR22HG/miR-9-3p in tumor regulation of SCLC. In conclusion, MIR22HG in SCLC was found to modulate miR-9-3p level and might act as a possible biomarker for SCLC treatment.

Prevalence of delta-like ligand 3 expression in small cell lung cancer.

e20618 Background: Delta-like ligand 3 (DLL3), a ligand of the Notch-family, is a potential therapeutic target in small cell lung cancer (SCLC). High expression levels of DLL3 are observed in SCLC, however different methods and thresholds are used. A systematic literature review (SLR) was conducted to estimate the prevalence of DLL3 expression in SCLC. Methods: A comprehensive literature search was conducted in the PubMed, EMBASE, Web of Science, and Cochrane Library databases, as well as on clinicaltrials.gov, using a pre-specified search strategy. This SLR was conducted and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The protocol was registered in the International Prospective Register of Systematic Reviews (CRD42022351119). Prevalence of DLL3 expression was evaluated overall and by method of DLL3 assessment and positivity threshold. Results: Of the 30 studies that met our study inclusion criteria, 22 (73.3%) were observational and 8 (26.7%) were clinical trials. Most studies (N = 21, 70%) evaluated less than 100 patient specimens (range: 20 to 1,362 patient specimens). Twelve studies (40%) were conducted in Asia, six (20%) in Europe, five (17%) in North America, five (17%) were multi-country, one in Brazil, and geographical location was not reported in one study. DLL3 testing methods varied across studies, with immunohistochemistry (IHC) being used in 26 (86.7%) studies. Two studies used real-time polymerase chain reaction, one used quantitative mass spectrometry, and one study did not report the testing method. Thirteen of the studies (13/26, 50%) that evaluated DLL3 expression by IHC used the Ventana SP347 assay. DLL3 expression was evaluated at various thresholds of tumor cell staining and showed a wide range of expression, across studies (Table). Conclusions: The SLR findings indicate that most studies assessing DLL3 in SCLC have relied on IHC methodology. Despite the range of thresholds used for evaluating positivity, DLL3 is notably expressed in SCLC. The frequency and impact of aberrant DLL3 localization was not addressed in these studies and minimal data on comparison of IHC with other methodologies exists. Results of this SLR also highlight the need to define a standardized method and threshold of evaluating DLL3 expression. [Table: see text]

Heterogeneous distribution pattern of CD3+ tumor-infiltrated lymphocytes (TILs) and high combined positive score (CPS) favored the prognosis of resected early stage small-cell lung cancer

PurposeThis study aimed to illustrate the heterogeneity of immune features in small cell lung cancer (SCLC). MethodsImmunohistochemistry (IHC) staining of CD3, CD4, CD8 and PD-L1 were performed with 55 SCLC FFPE samples from radical resections. Quantitative assessment of CD3+ tumor-infiltrated lymphocytes (TILs) to present the heterogeneity in the tumor and the stroma areas. Hotspots of TILs were evaluated to illustrate the potential relationship between TIL-density and its immune competence. Programmed death ligand-1 (PD-L1) expressed on both tumor TILs (t-TILs) and stroma TILs (s-TILs) was evaluated and quantitatively described as values of tumor positive score (TPS) and combined positive score (CPS). The clinical value of TPS and CPS were further identified according to their relationship with disease-free survival (DFS). ResultsMore abundant CD3+ TILs were observed in the tumor stroma than that within the parenchyma (15.02±2.25% vs. 1.58±0.35%) . The amount of CD3+ s-TILs were positively correlated with DFS. The CD3+/CD4+ subset of the TILs was found more favorable to DFS compared to the CD3+/CD8+ subset. Hotspots of CD3+ TILs were observed in tumor regions and patients with more Hotspots of CD3+ TILs have better outcomes. CPS were more reliable than TPS to describe PD-L1 expression in SCLC and it was found positively correlated with tumor size and DFS. ConclusionsThe immune microenvironment of SCLC was heterogeneous. Hotspots, the amount of CD3/CD4+ TILs and the CPS value were found valuable in determine the anti-tumor immunity and predicting the clinical outcome of SCLC patients.

DNA-PKcs as an upstream mediator of OCT4-induced MYC activation in small cell lung cancer

Small cell lung cancer (SCLC) is a neuroendocrine tumor noted for the rapid development of both metastases and resistance to chemotherapy. High mutation burden, ubiquitous loss of TP53 and RB1, and a mutually exclusive amplification of MYC gene family members contribute to genomic instability and make the development of new targeted agents a challenge. Previously, we reported a novel OCT4-induced MYC transcriptional activation pathway involving c-MYC, pOCT4S111, and MAPKAPK2 in progressive neuroblastoma, also a neuroendocrine tumor. Using tumor microarray analysis of clinical samples and preclinical models, we now report a correlation in expression between these proteins in SCLC. In correlating c-MYC protein expression with genomic amplification, we determined that some SCLC cell lines exhibited high c-MYC without genomic amplification, implying amplification-independent MYC activation. We then confirmed direct interaction between OCT4 and DNA-PKcs and identified specific OCT4 and DNA-PKcs binding sites. Knock-down of both POU5F1 (encoding OCT4) and PRKDC (encoding DNA-PKcs) resulted in decreased c-MYC expression. Further, we confirmed binding of OCT4 to the promoter/enhancer region of MYC. Together, these data establish the presence of a DNA-PKcs/OCT4/c-MYC pathway in SCLCs. We then disruptively targeted this pathway and demonstrated anticancer activity in SCLC cell lines and xenografts using both DNA-PKcs inhibitors and a protein-protein interaction inhibitor of DNA-PKcs and OCT4. In conclusion, we demonstrate here that DNA-PKcs can mediate high c-MYC expression in SCLCs, and that this pathway may represent a new therapeutic target for SCLCs with high c-MYC expression.

Abstract 3196: Subtype-specific targeting of cell surfaceome with CAR T therapies in small cell lung cancer

Abstract Background: Small cell lung cancer (SCLC) is a highly lethal malignancy with limited treatment options. Most SCLC are “immune-cold” and respond poorly to immunotherapy. Targeting SCLC cell surfaceome with cellular therapies have shown promising efficacy and tolerability in DLL3-targeting CAR T (AMG119) and Bispecific T-cell engager (tarlatamab). Recent work has defined subtypes of SCLC based on master transcription factors ASCL1 (SCLC-A), NEUROD1 (SCLC-N), POU2F3 (SCLC-P) and an immune cell-rich “inflamed” subtype(SCLC-I). Notably, SCLC-A and SCLC-N express neuroendocrine (NE) features while SCLC-P and SCLC-I are non-neuroendocrine (non-NE). We hypothesize that SCLC may have distinct surfaceome expressions based on their subtypes, which can be successfully targeted with cellular therapies such as CAR T. Methods: Transcriptional profiling of patient tumors identified several putative cell surfaceome targets in SCLC. We confirmed their expression level by Western blot and flow cytometry in SCLC cell lines stratified by subtypes. Top targets were selected based on abundant expression in SCLC and restricted normal tissue expression. We then constructed third-generation CAR T-cells against the top targets and tested their efficacy in cancer cell/CAR T co-culture models and in vivo. Results: We validated cell surface expression of top targets DLL3, CD56 and GD2; and generated CAR Ts against these targets to test cytotoxicity across a large panel of SCLC cell lines. Specifically, DLL3 is present predominantly in SCLC-A and SCLC-N (NE) subtypes. CAR T against DLL3 showed robust cytotoxicity in vitro against DLL3-expressing cell lines (5 out of 6 SCLC-A/N cell lines, versus 1 out of 6 SCLC-P/I cell lines; median cytotoxicity 94% vs. 43%, p=0.0082, Mann-Whitney U test), as well as promising in vivo activity. We also confirmed CD56 (NCAM1) was broadly expressed on the cell surface in SCLC A/P/N subtypes, and 8 out of 9 cell lines with high CD56 expression demonstrated over 50% cytotoxicity in co-culture models. GD2 was found to be enriched specifically in SCLC-N subtype of SCLC. As expected, GD2-targeting CAR T had higher cytotoxicity in SCLC-N subtypes of SCLC compared to other subtypes (median cytotoxicity 91% vs 22%, p=0.047). Moreover, given that novel therapeutics are often tested in the relapsed setting, we tested target expressions in SCLC cell lines after treatment with cisplatin and etoposide (standard frontline chemotherapy for SCLC) to see if target levels change. We found that surface target expressions increased instead of decreased in most cell lines, suggesting that they may be suitable targets in the relapsed setting also. Conclusion: This study demonstrated efficacy of CAR Ts targeting several cell surfaceome targets enriched in certain subtypes of SCLC. The data supports further investigation of a subtype-specific personalized treatment of SCLC using CAR T therapies against surfaceome targets. Citation Format: Bingnan Zhang, Yan Yang, C.Allison Stewart, Kavya Ramkumar, Runsheng Wang, Robert Cardnell, Lixia Diao, Qi Wang, Jing Wang, Lauren Byers, Carl Gay, John Heymach. Subtype-specific targeting of cell surfaceome with CAR T therapies in small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3196.

Clinical and prognostic implications of CD47 and PD-L1 expression in surgically resected small-cell lung cancer

Pharmacological inhibition of the immune-checkpoint molecule CD47 has shown promising results in preclinical small-cell lung cancer (SCLC) models, whereas anti-programmed death-ligand 1 (PD-L1) inhibitors have been recently implemented in the standard of care of advanced-stage SCLC patients. Nevertheless, the expression pattern, clinical relevance and prognostic implication of both CD47 and PD-L1 are rather controversial in surgically treated SCLC patients. In total, 104 Caucasian SCLC patients from two Central European thoracic centers were included in this study. CD47 and PD-L1 expression as well as the expression of the four major SCLC molecular subtype markers (ASCL1, NEUROD1, YAP1 and POU2F3) were measured by immunohistochemistry. Expression levels were independently evaluated and statistically correlated with clinicopathological data and survival. Positive CD47 and PD-L1 expressions were seen in 84.6% and 9.6% of the samples, respectively. Meanwhile, the tumor-associated stroma was positive for PD-L1 in 59.6% of the cases. Stromal PD-L1 expression correlated with longer overall survival (OS) (versus PD-L1-negative stroma; median OS was 42 versus 14 months, respectively, P= 0.003) and was confirmed as an independent predictor of favorable outcome upon multivariate analysis (hazard ratio 0.530, 95% confidence interval 0.298-0.943, P= 0.031). Notably, neither CD47 nor PD-L1 presence was related to a distinct molecular SCLC subtype. CD47 shows a remarkably high expression while tumoral PD-L1 expression is generally low in surgically treated SCLC. Importantly, stromal PD-L1 expression may indicate a favorable clinical outcome and serve as a novel prognostic factor in these patients. Additional studies are warranted to further investigate the clinical impact of CD47 and PD-L1 expression in SCLC.

Association of CEA, NSE, CYFRA 21-1, SCC-Ag, and ProGRP with Clinicopathological Characteristics and Chemotherapeutic Outcomes of Lung Cancer.

The aim of this study was to investigate the association of serum carcinoembryonic antigen (CEA), nerve-specific enolase (NSE), cytokeratin 19 fragment (CYFRA21-1), squamous cell carcinoma antigen (SCC-Ag), and pro-gastrin-releasing peptide (ProGRP) with the clinicopathological characteristics and chemotherapeutic outcomes of patients with lung cancer. A total of 189 patients with lung cancer (lung cancer group) diagnosed at the Fourth Affiliated Hospital of Anhui Medical University from January 2020 to December 2021 were included. During the same period, 199 patients with benign lung disorders were included as the benign lung disease group and 75 healthy people were selected as the control group. The serum concentrations of CEA, NSE, CYFRA21-1, SCC-Ag, and ProGRP in all the 3 groups were analyzed and compared in patients with different lung cancer tumor-node-metastasis (TNM) stages and pathological classifications. Atotal of 11 patients with small cell lung cancer (SCLC) and 18 patients with lung adenocarcinoma (LAC) were further evaluated forthe dynamic changes of CEA, NSE, CYFRA21-1, SCC-Ag, and ProGRP before chemotherapy and during the 6 courses of chemotherapy, and the outcome of chemotherapy was evaluated every 2 courses. The serum concentrations of CEA, NSE, CYFRA21-1, SCC-Ag, and ProGRP in the lung cancer group were significantly higher than those in the control group (P < .05). We found statistically significant differences in serum CEA, NSE, CYFRA 21-1, SCC-Ag, and ProGRP among patients with different pathological types (LAC, squamous cell carcinoma, or SCLC) and different stages (I-IV). The ProGRP and NSE had the highest expression in SCLC, CEA showed the highest expression in LAC, whereas CYFRA21-1 and SCC-Ag showed the highest expression in lung squamous cell carcinoma (LSCC). The concentrations of all the markers were elevated in the advanced pathological stages. The receiver operating characteristic curve analysis showed that the diagnostic value of the combined detection of CEA, NSE, CYFRA 21-1, SCC-Ag, and ProGRP for lung cancer was significantly higher than using a single biomarker (P < .05). Our dynamic monitoring results show that ProGRP progressively decreased in remission cases of SCLC and CEA progressively decreased in LAC remission cases. CEA, NSE, CYFRA 21-1, SCC-Ag, and ProGRP have good clinical value in the early diagnosis, differential diagnosis, and progression monitoring of lung cancer. The ProGRP and CEA concentrations are beneficial for evaluating the outcome of chemotherapy in SCLC and LAC. The combined detection of multiple biomarkers shows improved clinical value in the early diagnosis of lung cancer.

The clinical significance of integrin subunit alpha V in cancers: from small cell lung carcinoma to pan-cancer

BackgroundLittle is known about the relationship between integrin subunit alpha V (ITGAV) and cancers, including small cell lung cancer (SCLC).MethodsUsing large sample size from multiple sources, the clinical roles of ITGAV expression in SCLC were explored using differential expression analysis, receiver operating characteristic curves, Kaplan–Meier curves, etc.ResultsDecreased mRNA (SMD = − 1.05) and increased protein levels of ITGAV were detected in SCLC (n = 865). Transcription factors—ZEB2, IK2F1, and EGR2—may regulate ITGAV expression in SCLC, as they had ChIP-Seq (chromatin immunoprecipitation followed by sequencing) peaks upstream of the transcription start site of ITGAV. ITGAV expression made it feasible to distinguish SCLC from non-SCLC (AUC = 0.88, sensitivity = 0.78, specificity = 0.84), and represented a risk role in the prognosis of SCLC (p < 0.05). ITGAV may play a role in cancers by influencing several immunity-related signaling pathways and immune cells. Further, the extensive pan-cancer analysis verified the differential expression of ITGAV and its clinical significance in multiple cancers.ConclusionITGAV served as a potential marker for prognosis and identification of cancers including SCLC.

Multi-Omics Integration-Based Prioritisation of Competing Endogenous RNA Regulation Networks in Small Cell Lung Cancer: Molecular Characteristics and Drug Candidates.

BackgroundThe competing endogenous RNA (ceRNA) network-mediated regulatory mechanisms in small cell lung cancer (SCLC) remain largely unknown. This study aimed to integrate multi-omics profiles, including the transcriptome, regulome, genome and pharmacogenome profiles, to elucidate prioritised ceRNA characteristics, pathways and drug candidates in SCLC.MethodWe determined the plasma messenger RNA (mRNA), microRNA (miRNA), long noncoding RNA (lncRNA) and circular RNA (circRNA) expression levels using whole-transcriptome sequencing technology in our SCLC plasma cohort. Significantly expressed plasma mRNAs were then overlapped with the Gene Expression Omnibus (GEO) tissue mRNA data (GSE 40275, SCLC tissue cohort). Next, we applied a multistep multi-omics (transcriptome, regulome, genome and pharmacogenome) integration analysis to first construct the network and then to identify the lncRNA/circRNA-miRNA-mRNA ceRNA characteristics, genomic alterations, pathways and drug candidates in SCLC.ResultsThe multi-omics integration-based prioritisation of SCLC ceRNA regulatory networks consisted of downregulated mRNAs (CSF3R/GAA), lncRNAs (AC005005.4-201/DLX6-AS1-201/NEAT1-203) and circRNAs (hsa_HLA-B_1/hsa_VEGFC_8) as well as upregulated miRNAs (hsa-miR-4525/hsa-miR-6747-3p). lncRNAs (lncRNA-AC005005.4-201 and NEAT1-203) and circRNAs (circRNA-hsa_HLA-B_1 and hsa_VEGFC_8) may regulate the inhibited effects of hsa-miR-6747-3p for CSF3R expression in SCLC, while lncRNA-DLX6-AS1-201 or circRNA-hsa_HLA-B_1 may neutralise the negative regulation of hsa-miR-4525 for GAA in SCLC. CSF3R and GAA were present in the genomic alteration, and further identified as targets of FavId and Trastuzumab deruxtecan, respectively. In the SCLC-associated pathway analysis, CSF3R was involved in the autophagy pathways, while GAA was involved in the glucose metabolism pathways.ConclusionsWe identified potential lncRNA/cirRNA-miRNA-mRNA ceRNA regulatory mechanisms, pathways and promising drug candidates in SCLC, providing novel potential diagnostics and therapeutic targets in SCLC.

ABBV-011, A Novel, Calicheamicin-Based Antibody-Drug Conjugate, Targets SEZ6 to Eradicate Small Cell Lung Cancer Tumors.

In the past year, four antibody-drug conjugates (ADC) were approved, nearly doubling the marketed ADCs in oncology. Among other attributes, successful ADCs optimize targeting antibody, conjugation chemistry, and payload mechanism of action. Here, we describe the development of ABBV-011, a novel SEZ6-targeted, calicheamicin-based ADC for the treatment of small cell lung cancer (SCLC). We engineered a calicheamicin conjugate that lacks the acid-labile hydrazine linker that leads to systemic release of a toxic catabolite. We then screened a patient-derived xenograft library to identify SCLC as a tumor type with enhanced sensitivity to calicheamicin ADCs. Using RNA sequencing (RNA-seq) data from primary and xenograft SCLC samples, we identified seizure-related homolog 6 (SEZ6) as a surface-expressed SCLC target with broad expression in SCLC and minimal normal tissue expression by both RNA-seq and IHC. We developed an antibody targeting SEZ6 that is rapidly internalized upon receptor binding and, when conjugated to the calicheamicin linker drug, drives potent tumor regression in vitro and in vivo. These preclinical data suggest that ABBV-011 may provide a novel treatment for patients with SCLC and a rationale for ongoing phase I studies (NCT03639194).

Evaluation of PD-L1 expression on circulating tumour cells in small-cell lung cancer.

BackgroundAntibodies against the programmed death-1 (PD-1) receptor and its ligand (PD-L1) have been recently approved for small-cell lung cancer (SCLC) treatment. Circulating tumour cells (CTCs) have emerged as an appealing liquid biopsy candidate that could enhance treatment decision-making in systemic therapy for SCLC patients. Several current technologies enrich CTCs using specific surface epitopes, size, rigidity, or dielectric properties. However, they are hampered by the heterogeneity of the enriched cells from blood samples.MethodsWe evaluated two CTC enrichment systems: EpCAM conjugated to magnetic beads and a microfluidic device (Parsortix, Angle plc). PD-L1 expression was evaluated on the isolated CTCs. Twenty-three blood samples were collected from 21 patients with SCLC. PD-L1 expression was determined on CTCs through immunofluorescent staining.ResultsCTCs were found in 14/23 (60.9%) of the samples, with 11/23 (47.8%) through EpCAM-coated magnetic beads (range, 4–1,611 CTCs/8 mL; median =5) and 11/20 (55.0%) using the Parsortix system (range, 1–165 CTCs/8 mL; median =4). Notably, a total of 17 EpCAM-negative CTCs were isolated using the Parsortix system. PD-L1 expression was detected on 268 of the 3,501 (7.7%) CTCs isolated with EpCAM-coated beads and in 33/366 (9.0%) of the CTCs isolated with the Parsortix system. No vimentin expression was observed in any of the detected CTCs.ConclusionsOverall, we identified a population of EpCAM-negative SCLC CTCs and showed that PD-L1 expression can be assessed on CTCs from SCLC patients. Comparison to tumour and treatment outcomes is needed to validate the potential of CTCs as an alternative sample for the assessment of PD-L1 expression in SCLC.

YAP1 protein expression has variant prognostic significance in small cell lung cancer (SCLC) stratified by histological subtypes

BackgroundRecently, expression of YAP1, a nuclear effector of an inactivated HIPPO pathway, has been identified as one of four molecular subtypes of SCLC. However, the clinicopathological relevance and prognostic significance of YAP1 expression in SCLC stratified by histological subtypes has not been systematically reported to date. MethodsTumor sections and corresponding formalin-fixed paraffin-embedded (FFPE) samples of 297 SCLC patients were retrieved from the pathological specimen repository and were subsequently reviewed by pathologists. Forty-six C-SCLCs (combined SCLCs) (15.5%) and 251P-SCLCs (pure SCLCs) (84.5%) were identified respectively. YAP1 expression was examined by immunohistochemistry (IHC) and assessed semi-quantitatively on tumor tissue array (TMA). Propensity score was used to match C-SCLCs and P-SCLCs in a ratio of 1 to 2 to balance age, gender, tumor stage and treatment methods. Finally, 46C-SCLCs and 92P-SCLCs were included for prognostic analysis. ResultsThe positive rate of YAP1 expression was significantly higher in C-SCLCs than P-SCLCs before matching (52.2% vs 29.1%, P = 0.004). After matching by propensity score, the prescribed clinical parameters were well balanced between P-SCLCs and C-SCLCs. Expression of YAP1 was associated worse overall survival (OS) (5- year OS%, 39.0% vs. 74.9%, P = 0.013) and was an independent risk factor for OS (HR = 2.93, 95% CI: 1.01–8.51; P = 0.048) exclusively in C-SCLC. Univariate survival analysis in subgroups of different clinical variables also confirmed the prognostic impact of YAP1 was most significant in C-SCLC. But for P-SCLCs, expression of YAP1 showed no prognostic impact. ConclusionsExpression of YAP1 in small cell components of C-SCLC was significantly higher than that in P-SCLC. Besides, it served as an unfavorable predictor for OS in C-SCLC but not in P-SCLC, which suggested different entities of small cell components with variant YAP1 expression and potential different targetable oncogenic pathway between C-SCLC and P-SCLC.

Predicting ROR1/BCL2 combination targeted therapy of small cell carcinoma of the lung

Small cell lung cancer (SCLC) remains a deadly form of cancer, with a 5-year survival rate of less than 10 percent, necessitating novel therapies. Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is an oncofetal protein that is emerging as a therapeutic target and is co-expressed with BCL2 in multiple tumor types due to microRNA coregulation. We hypothesize that ROR1-targeted therapy is effective in small cell lung cancer and synergizes with therapeutic BCL2 inhibition. Tissue microarrays (TMAs) and formalin-fixed paraffin-embedded (FFPE) SCLC patient samples were utilized to determine the prevalence of ROR1 and BCL2 expression in SCLC. Eight SCLC-derived cell lines were used to determine the antitumor activity of a small molecule ROR1 inhibitor (KAN0441571C) alone and in combination with the BCL2 inhibitor venetoclax. The Chou-Talalay method was utilized to determine synergy with the drug combination. ROR1 and BCL2 protein expression was identified in 93% (52/56) and 86% (48/56) of SCLC patient samples, respectively. Similarly, ROR1 and BCL2 were shown by qRT-PCR to have elevated expression in 79% (22/28) and 100% (28/28) of SCLC patient samples, respectively. KAN0441571C displayed efficacy in 8 SCLC cell lines, with an IC50 of 500 nM or less. Synergy as defined by a combination index of <1 via the Chou-Talalay method between KAN0441571C and venetoclax was demonstrated in 8 SCLC cell lines. We have shown that ROR1 inhibition is synergistic with BCL2 inhibition in SCLC models and shows promise as a novel therapeutic target in SCLC.

Delta-like 1 homolog (DLK1) as a possible therapeutic target and its application to radioimmunotherapy using 125I-labelled anti-DLK1 antibody in lung cancer models (HOT1801 and FIGHT004)

ObjectivesDelta-like 1 homolog (DLK1) is a non-canonical Notch ligand known to be expressed in several cancers but whose role in lung cancer is not yet fully understood. We sought to confirm DLK1 expression in small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC), and to examine DLK1’s clinical significance. Furthermore, we examined the possible utility of DLK1 as a novel target in radioimmunotherapy (RIT). MethodsWe retrospectively assessed the correlation between clinical features and DLK1 expression by immunohistochemistry in resected specimens from 112 patients with SCLC and 101 patients with NSCLC. Moreover, we performed cell and animal experiments, and examined the possibility of RIT targeting DLK1 in SCLC using iodine-125 (125I) -labeled anti-DLK1 antibody, knowing that 125I can be replaced with the alpha-particle-emitter astatine-211 (211At). ResultsIn SCLC and NSCLC, 20.5 % (23/112) and 16.8 % (17/101) of patients (respectively) had DLK1-positive tumors. In NSCLC, DLK1 expression was associated with recurrence-free survival (P < 0.01) but not with overall survival. In SCLC, there was no association between DLK1 expression and survival. In addition, 125I-labeled anti-DLK1 antibody specifically targeted DLK1 on human SCLC tumor cell lines. Furthermore, 125I-labeled anti-DLK1 antibody was incorporated into tumor tissue in a mouse model. ConclusionA proportion of SCLC and NSCLC exhibits DLK1 expression. As a clinical feature, DLK1 expression could be a promising prognostic factor for recurrence in patients with resected NSCLC. In addition, DLK1 could serve as a new therapeutic target, including RIT, as suggested by our pilot study using a radiolabeled anti-DLK1 antibody in SCLC.