Small Cell Lung Carcinoma Tumors Research Articles

Sacituzumab govitecan plus platinum-based chemotherapy mediates significant antitumor effects in triple-negative breast, urinary bladder, and small-cell lung carcinomas.

Sacituzumab govitecan (SG) is an antibody-drug conjugate composed of an anti-Trop-2-directed antibody conjugated with the topoisomerase I inhibitory drug, SN-38, via a proprietary hydrolysable linker. SG has received United States Food and Drug Administration (FDA) approval to treat metastatic triple-negative breast cancer (TNBC), unresectable locally advanced or metastatic hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer, and accelerated approval for metastatic urothelial cancer. We investigated the utility of combining SG with platinum-based chemotherapeutics in TNBC, urinary bladder carcinoma (UBC), and small-cell lung carcinoma (SCLC). SG plus carboplatin or cisplatin produced additive growth-inhibitory effects in vitro that trended towards synergy. Immunoblot analysis of cell lysates suggests perturbation of the cell-cycle and a shift towards pro-apoptotic signaling evidenced by an increased Bax to Bcl-2 ratio and down-regulation of two anti-apoptotic proteins, Mcl-1 and survivin. Significant antitumor effects were observed with SG plus carboplatin in mice bearing TNBC or SCLC tumors compared to all controls (P < 0.0062 and P < 0.0017, respectively) and with SG plus cisplatin in UBC and SCLC tumor-bearing animals (P < 0.0362 and P < 0.0001, respectively). These combinations were well tolerated by the animals. Combining SG with platinum-based chemotherapeutics demonstrates the benefit in these indications and warrants further clinical investigation.

Novel Mouse Cell Lines and In Vivo Models for Human High-Grade Neuroendocrine Lung Carcinoma, Small Cell Lung Carcinoma (SCLC), and Large Cell Neuroendocrine Carcinoma (LCNEC).

There is a clear need to expand the toolkit of adequate mouse models and cell lines available for preclinical studies of high-grade neuroendocrine lung carcinoma (small cell lung carcinoma (SCLC) and large cell neuroendocrine carcinoma (LCNEC)). SCLC and LCNEC are two highly aggressive tumor types with dismal prognoses and few therapeutic options. Currently, there is an extreme paucity of material, particularly in the case of LCNEC. Given the lack of murine cell lines and transplant models of LCNEC, the need is imperative. In this study, we generated and examined new models of LCNEC and SCLC transplantable cell lines derived from our previously developed primary mouse LCNEC and SCLC tumors. RNA-seq analysis demonstrated that our cell lines and syngeneic tumors maintained the transcriptome program from the original transgenic primary tumor and displayed strong similarities to human SCLC or LCNEC. Importantly, the SCLC transplanted cell lines showed the ability to metastasize and mimic this characteristic of the human condition. In summary, we generated mouse cell line tools that allow further basic and translational research as well as preclinical testing of new treatment strategies for SCLC and LCNEC. These tools retain important features of their human counterparts and address the lack of LCNEC disease models.

Tumor-derived Vimentin as a novel biomarker for distinct subtypes predicting adjuvant chemotherapy resistance and T-cell-inflamed phenotype in small cell lung cancer.

Despite recent progress in subtype classification for small cell lung carcinoma (SCLC), little is known about the biomarker for triple-negative (ASCL1, NEUROD1, and POU2F3 negative) tumors. The long-term survival, adjuvant chemotherapy (ACT) response, and immune milieu in different SCLC subtypes have also not been well established. Here, we retrospectively collected a large cohort of 192 primary SCLC tumors and reported that ASCL1-, NEUROD1- and POU2F3-dominant subtypes counted for 61.38%, 19.31%, and 6.21%, respectively. Subtype intra-tumoral heterogeneity and co-expression at the single-cell level existed substantially. The expression of tumor-derived Vimentin (VIM) was nearly restricted to triple-negative SCLC tumors (15/19, 78.9%) while YAP1 expression was distributed widely in other subtypes. The SCLC subtyping model was independently prognostic of OS and RFS (p < 0.001 and p=0.043). In particular, patients with ASCL1-positive SCLC tumors can benefit more from ACT, and VIM-positive tumors did the opposite. Compared with other subtypes, the VIM-dominant SCLC subtype was associated with abundant but functionally impaired CD4+ and CD8+ T-cells, which highly expressed inhibitory checkpoints and potentially benefit from PD-L1 blockade therapy. Our study showed that tumor-derived SCLC-V subtype could independently predict ACT response. The distinct immune landscape between subtypes may help inform personalized immune therapeutic approaches.

Abstract 1560: Orally bioavailable macrocycles that target cyclins A and B RxL motifs cause tumor regression in xenograft models and in vitro show activity across multiple cancer types

Abstract RB and E2F genes are frequently altered in cancer. Cyclin/Cdk (cyclin-dependent kinase) complexes regulate the activity of RB and E2F to drive cell cycle progression and ensure fidelity of DNA replication. A critical subset of their substrates (Rb, E2F, Cdc6, etc.) requires a short linear motif (RxL) that interacts with the hydrophobic patch on cyclins. Peptides that disrupt the cyclin/RxL interaction were found to be synthetically lethal in cancer cell lines displaying Rb-E2F dysregulation (Chen, 1999). Using structure-guided design, cell-permeable macrocycles were synthesized that selectively inhibit RxL-mediated binding to cyclins A and B. Preclinical studies with an orally bioavailable cyclin A/B RxL inhibitor show activity in cell lines with Rb-E2F pathway dysregulation, and inhibition of tumor growth and regression in xenograft models of small cell lung carcinoma (SCLC). RB-null mutations occur with high frequency in SCLC tumors (Febres-Aldana 2022). Previously we reported (AACR April 2022 Abs.#5379) sensitivity of a large proportion of SCLC cell lines to cyclin RxL inhibitors. Further studies have shown that such compounds have growth inhibitory activity in cell lines representing multiple types of solid tumors and hematological malignancies. Sensitivity of the cell lines to these macrocyclic inhibitors is associated with increased expression of genes involved in the E2F pathway, consistent with the proposed Rb/cyclin/E2F pathway synthetic lethality mechanism. Disruption of RxL binding to both cyclin A and B is required for sensitivity. Cyclin A/B RxL inhibitors disrupt the interactions of E2F and Cdc6 with cyclin A/Cdk complexes in co-immunoprecipitation studies and have EC50 values consistent with biochemical and cellular activity. Cyclin A/B RxL inhibition results in accumulation of cells in the G2/M phase of the cell cycle which leads to apoptosis both in vitro and in vivo. A separate study (Singh et al. AACR 2023) utilizing a CRISPR screen identified that genes of the spindle assembly checkpoint (SAC) are required for the synthetic lethality induced by the cyclin A/B RxL inhibitors. The inhibitors assessed in vitro for off-target activity showed negligible activity in a panel of 468 kinases and in safety panels that include GPCRs, ion channels, and transporters. In a 14-day tolerability study, neither neutropenia nor significant effects in other blood cell counts were noted. Cyclin A/B RxL inhibitors cause significant tumor regression via oral administration in SCLC xenograft models. Given their compelling characteristics, we are progressing the development of these orally bioavailable macrocyclic cyclin A/B RxL inhibitors to the clinic. Citation Format: Catherine E. Gleason, Pablo D. Garcia, Ranya Odeh, Frances Hamkins-Indik, Daphne He, Meisam Nosrati, Gavin Situ, Roberta Sala, Bernard Levin, Li-Fen Liu, Evelyn W. Wang, Siegfried Leung, Breena Fraga, Andrew T. Bockus, Justin Shapiro, Nathan Dupper, Chinmay Bhatt, Kai Yang, Megan DeMart, Sammy Metobo, James Aggen, Peadar Cremin, Ramesh Bambal, Constantine Kreatsoulas, David J. Earp, Rajinder Singh. Orally bioavailable macrocycles that target cyclins A and B RxL motifs cause tumor regression in xenograft models and in vitro show activity across multiple cancer types [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 1560.

Abstract 2229: Cell state transitions shape the intratumoral composition of small cell lung carcinoma

Abstract Introduction: Small cell lung carcinoma (SCLC) is characterized by rapid growth, early metastases, and initial response followed by almost invariable resistance to therapy. Studies to date have not determined the extent that diverse transcriptional programs drive SCLC and contribute to its lethality. We sought to characterize the intra-tumoral transcriptional heterogeneity of SCLC. We identify multivalent, distinct, and commutable transcriptional states that confer discrete functions in individual SCLC tumors. Methods: We developed a biorepository of patient-derived xenografts (PDX) (n = 64) and matched PDX-derived ex vivo lines. We used multi-omic profiling (RNAseq, scRNAseq, and ATAC seq), single-cell fluorescence tracking of fate-defining transcription factor (TF)-driven states, and mathematical and statistical models (Markov chain) to study the topology of the SCLC transcriptional landscape and its plasticity. Human tumor material and associated clinical data were obtained after informed written consent on an IRB-approved prospective registry. Results: We show that individual SCLC tumors are more heterogenous than previously appreciated, displaying distinctive equilibria in the proportion of cells within well-delimited cellular states (ASCL1, NEUROD1 and YAP1). We also show that transcriptional states undergo transitions, which we identified as a mechanism for maintaining cell state diversity. We measured the kinetics of state transitions using single-cell fluorescence tracking of ex vivo cultures and found that these measure were associated significantly with transition estimates using stochastic transition theory (i.e. Markov chains). ATAC-seq profiling indicated a role for the epigenome in the state diversity of SCLC. Namely, there was preferential promoter accessibility to Ascl1, NeuroD1, and Yap1 in a manner consistent with gene and protein expression in the respective subpopulations. Our results indicate that the transition rates between cell types in individual tumors were largely governed by tendencies to reach an equilibrium state that are critical for configuring intratumoral cell state proportions. Conclusion: In conclusion, we demonstrate that TF driven cell states can transition to maintain an equilibrium in cell state proportions. Our work advances a model of cellular states and program diversity in SCLC and nominates new therapeutic strategies designed to limit the plasticity of this lethal cancer. Citation Format: Priyanka Gopal, Aaron Petty, Kevin Rogacki, Titas Bera, Rohan Bareja, Craig Peacock, Mohamed Abazeed. Cell state transitions shape the intratumoral composition of small cell lung carcinoma [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 2229.

Multivalent state transitions shape the intratumoral composition of small cell lung carcinoma.

Studies to date have not resolved how diverse transcriptional programs contribute to the intratumoral heterogeneity of small cell lung carcinoma (SCLC), an aggressive tumor associated with a dismal prognosis. Here, we identify distinct and commutable transcriptional states that confer discrete functional attributes in individual SCLC tumors. We combine an integrative approach comprising the transcriptomes of 52,975 single cells, high-resolution measurement of cell state dynamics at the single-cell level, and functional and correlative studies using treatment naïve xenografts with associated clinical outcomes. We show that individual SCLC tumors contain distinctive proportions of stable cellular states that are governed by bidirectional cell state transitions. Using drugs that target the epigenome, we reconfigure tumor state composition in part by altering individual state transition rates. Our results reveal new insights into how single-cell transition behaviors promote cell state equilibrium in SCLC and suggest that facile plasticity underlies its resistance to therapy and lethality.

Multivalent state transitions regulate the intratumoral composition of small cell lung carcinoma.

e20587 Background: Small cell lung carcinoma (SCLC) is an aggressive, tobacco-associated tumor with neuroendocrine features characterized by rapid growth, metastatic progression, and initial response followed by almost invariable resistance to therapy. Studies to date have not resolved the extent that diverse transcriptional programs drive SCLC and contribute to its lethality. Methods: We combined one of the largest and most diverse inventories of patient-derived xenograft models of SCLC with an ex vivo culture system that maintains transcriptional fidelity with matched primary SCLC tumor to identify transcriptional state heterogeneity. Using the expression of the Ascl1, NeuroD1, and Yap1 as markers of well-conserved SCLC states, we developed a state-of-the-art fluorescent platform that can directly measure single-cell state transitions in a multi-layered ecosystem using tandemly integrated reporters. We modeled population dynamics using a discrete time Markov chain and directly measure single-cell state transitions. Results: We show significant cell-state heterogeneity in several SCLC primary tumors, patient-derived xenografts (PDX), and ex vivo cultures. These states comprise distinct subpopulations marked by the master regulatory transcription factors (TFs) Ascl1, NeuroD1, and Yap1. Ex vivo, the 3 TFs are associated with suspension aggregates of small neuroendocrine cells, pre-suspension (loosely adherent) aggregates, and large mesenchymal cells with visible cytoplasm and spindle-like membrane extensions, respectively. We have observed equilibria in cell-state proportions in SCLC tumors both in vivo (PDX) and ex vivo. In addition, we have shown that the “elasticity” of SCLC responses, measured as the extent of clinical response during chemotherapy followed by the time to relapse from the end of therapy, is dependent on tumor TF levels. These observations suggest that mechanistic modeling of intra-tumoral state dynamics is of high clinical relevance. Conclusions: Our integrative approach is poised to formulate and validate a unified model of cellular states and program diversity in SCLC. If successful, the characterization of malignant cell ontogenic programs, their plasticity, and the advancement of new therapies designed to combat plasticity by epigenetic reprogramming will create a new scientific canvas for the study of this highly lethal disease.

A phase I, open-label, dose-escalation trial of BI 764532, a DLL3/CD3 bispecific antibody, in patients (pts) with small cell lung carcinoma (SCLC) or other neuroendocrine neoplasms expressing DLL3.

TPS8588 Background: First-line standard of care for pts with metastatic SCLC and neuroendocrine carcinoma (NEC) is platinum-based chemotherapy ± immunotherapy. While the addition of anti-PD1 antibodies has improved outcomes, nearly all pts relapse and prognosis is poor. There is a major unmet need for additional treatment (tx) options. BI 764532 is a delta-like ligand 3 (DLL3)/CD3 T cell engaging bispecific antibody. DLL3 is expressed on the cell surface of many SCLC and NEC tumors, but not on normal cells. In preclinical studies, BI 764532 induced cytotoxicity of DLL3-positive cells and showed anti-tumor activity in animal models. Methods: NCT04429087 is a first-in-human, open-label, dose-escalation trial of BI 764532 in adults with locally advanced/metastatic SCLC, large cell neuroendocrine lung carcinoma, NEC or small cell carcinoma of any other origin. Pts must have failed on or be ineligible for available standard therapies (including ≥1 line of platinum-based chemotherapy). Tumors must be positive for DLL3 expression (archived tissue/in-study fresh biopsy) according to central review. Pts must have ≥1 evaluable lesion (modified RECIST 1.1) outside of CNS and adequate liver, bone marrow and renal organ function. Main exclusion criteria: previous tx with T cell engagers or DLL3-targeted therapies; persistent toxicity from previous tx that has not resolved to ≤ CTCAE grade 1; immunodeficiency or receiving immunosuppressive therapy ≤7 days, prior anti-cancer therapy ≤3 wks/5 half-life periods or extensive field radiotherapy ≤2 wks of first dose of BI 764532. The main objective of phase Ia is to determine the maximum tolerated dose (MTD) or recommended dose for expansion of BI 764532, based on dose-limiting toxicities during the MTD evaluation period. Further objectives are to evaluate safety, tolerability, PK/PD and preliminary efficacy. The phase Ib objectives, endpoints and design will be specified after availability of phase Ia results. The trial will assess ≤3 dosing regimens: Regimen A (fixed iv dose once every 3 wks); Regimen B1 (fixed iv dose once every wk); Regimen B2 (step-in dose[s] followed by fixed-dose weekly doses; optional). Tx will continue until confirmed progressive disease, unacceptable toxicity, other withdrawal criteria or a maximum tx duration of 36 mos, whichever occurs first. For Phase Ia, ̃160 pts will be screened and 110 pts accrued. As of Feb 2021, pts are being recruited and treated in early dose escalation cohorts. Clinical trial information: NCT04429087.

Cross-Site Concordance Evaluation of Tumor DNA and RNA Sequencing Platforms for the CIMAC-CIDC Network.

Whole-exome (WES) and RNA sequencing (RNA-seq) are key components of cancer immunogenomic analyses. To evaluate the consistency of tumor WES and RNA-seq profiling platforms across different centers, the Cancer Immune Monitoring and Analysis Centers (CIMAC) and the Cancer Immunologic Data Commons (CIDC) conducted a systematic harmonization study. DNA and RNA were centrally extracted from fresh frozen and formalin-fixed paraffin-embedded non-small cell lung carcinoma tumors and distributed to three centers for WES and RNA-seq profiling. In addition, two 10-plex HapMap cell line pools with known mutations were used to evaluate the accuracy of the WES platforms. The WES platforms achieved high precision (> 0.98) and recall (> 0.87) on the HapMap pools when evaluated on loci using > 50× common coverage. Nonsynonymous mutations clustered by tumor sample, achieving an index of specific agreement above 0.67 among replicates, centers, and sample processing. A DV200 > 24% for RNA, as a putative presequencing RNA quality control (QC) metric, was found to be a reliable threshold for generating consistent expression readouts in RNA-seq and NanoString data. MedTIN > 30 was likewise assessed as a reliable RNA-seq QC metric, above which samples from the same tumor across replicates, centers, and sample processing runs could be robustly clustered and HLA typing, immune infiltration, and immune repertoire inference could be performed. The CIMAC collaborating laboratory platforms effectively generated consistent WES and RNA-seq data and enable robust cross-trial comparisons and meta-analyses of highly complex immuno-oncology biomarker data across the NCI CIMAC-CIDC Network.

IBS19.02 Novel Radiotherapy Approaches in Small Cell Lung Carcinoma – Has SABR and Radionuclide Therapy Got a Role to Play?

Thoracic radiotherapy has been shown in to increase overall survival when added to systemic therapy in patients with small cell lung carcinoma (SCLC) and M0 stage. The dose, fractionation, treatment time and timing issues have not been fully resolved. A recent study did not show the superiority of 66Gy in 33 daily fractions over 6.5 weeks over twice-daily radiotherapy to a dose of 45 Gy in 30 fractions over 3 weeks twice daily [1]. For stage I non-small cell lung carcinoma (NSCLC), stereotactic ablative body radiotherapy (SABR) has been clearly shown to be superior to conventional fractionation [2]. Given the clear benefit seen in early stage NSCLC, it is postulated that SABR may have a role to play in early stage SCLC. A recent multi-institutional cohort study has reported favourable outcomes in this setting [3]. However, randomised data of equivalence or indeed superiority are lacking. Furthermore, questions remain as the timing and role of systemic therapy and prophylactic cranial irradiation when SABR is used in this setting. In advanced SCLC, many tumors display neuroendocrine clinical and cytological features and many SCLC tumors express somatostatin receptor and this can be imaged using radiolabeled somatostatin analogs such as 68Ga-DOTATATE [4]. Given the uptake by some SCLC tumors of 68Ga-DOTATATE, higher doses of the tracer have been used in an attempt to provide radiolabelled radiotherapy treatment in metastatic disease in what has been described as peptide receptor radionuclide therapy (PRRT) [5]. This molecularly target radiotherapy is a potentially exciting therapeutic approach, but the ideal positioning of such therapy in tumors which are suitable for treatment with PRRT and the safety of PRRT with systemic therapy have yet to be determined. 1. Faivre-Finn C, Snee M, Ashcroft L, et al. Concurrent once-daily versus twice-daily chemoradiotherapy in patients with limited-stage small-cell lung cancer (CONVERT): an open-label, phase 3, randomised, superiority trial. Lancet Oncol. 2017;18(8):1116–1125. https://doi.org/10.1016/S1470-2045(1730318-2) 2. Ball D, Mai GT, Vinod S, et al. Stereotactic ablative radiotherapy versus standard radiotherapy in stage 1 non-small cell lung cancer (TROG 09.02. CHISEL): a phase 3, open-label, randomised controlled trial. The Lancet. 2019; 20: 494-503 3. Verma V, Simone CB, 2nd, Allen PK, et al. Multi-Institutional Experience of Stereotactic Ablative Radiation Therapy for Stage I Small Cell Lung Cancer. Int J Radiat Oncol Biol Phys 2017;97:362-71 4. Sollini M, Farioli D, Froio A, et al. Brief Report on the Use of Radiolabeled Somatostatin Analogs for the Diagnosis and Treatment of Metastatic Small-Cell Lung Cancer Patients. J Thor Oncol 2013;8(8):1095-1101. 5. Lapa C, Hänscheid H, Wild V, et al. Somatostatin receptor expression in small cell lung cancer as a prognostic marker and a target for peptide receptor radionuclide therapy. Oncotarget. 2016 Apr 12;7(15):20033-40. SCLC, SABR, radiotherapy

SMALL CELL LUNG CARCINOMA WITH THREE PARANEOPLASTIC SYNDROMES IN ONE PATIENT

SESSION TITLE: Monday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/21/2019 02:30 PM - 03:15 PM INTRODUCTION: This is a case of patient who was diagnosed with Small Cell Lung Carcinoma(SCLC)after presenting with symptoms of Dermatomyositis(DM), SIADH and Lambert–Eaton myasthenic(LEMS)syndrome CASE PRESENTATION: Patient initially presented to the clinic with erythematous patches scattered on the trunk, extremities, and scalp associated with pain, itchiness and hair loss for two months. Biopsy from rash showed perifollicular and mild superficial perivascular inflammation. The patient was treated for viral exanthem with steroids. Patient subsequently presented to the hospital with worsening pruritic patches on scalp and entire body and periorbital edema. This was associated with weakness and generalized malaise. The weakness and pain were worse with neck and shoulder movements and the weakness improved on exertion. Other symptoms were productive cough, rhinorrhea, nasal congestion and sore throat for a month associated with 20 pounds weight loss. Physical exam showed decreased breath sounds in the left upper and middle field.No lower extremity swelling.Skin findings were violaceous edematous periorbital erythema(heliotrope rash), erythema of neck, upper chest, and entire back, erythematous slightly scaly plaques overlying MCPs and PIPs(Gottron's papules). Labs showed CPK of 868, Aldolase of 8.9, serum sodium of 115(Serum osmolality 248, Urine osmolality 497, TSH 1.7, random cortisol 20.7)and ANA(1:320)was positive. Chest x-ray showed left upper lobe mass. CT chest showed malignant process arising from the left upper lobe and to the mediastinum. She underwent bronchoscopy with FNA and endobronchial biopsy which showed SCLC. DISCUSSION: Paraneoplastic syndromes occur in approximately 10% of patients with lung cancer(1). SIADH occurs in 15% of SCLC patients. LEMS is present in approximately 1% to 3% of patients with SCLC. Off all cases of DM only 5.9% have lung cancer. In some cases these syndromes can be presenting sign of cancer. The early recognition of paraneoplastic syndromes may contribute to the detection of a highly treatable, early-stage tumor. At other times, the syndromes may occur late in the course of disease or may appear as the first sign of recurrence DM is associated with poor prognosis and improved SCLC tumor survival are seen in patients with LEMS(2). Management of hyponatremia is very important as it is associated with a poor prognosis regardless of an extensive or limited stage. SCLC patients with serum sodium less than 129 mmol/l had a median survival of 8.63 months compared to 13.6 months in patients with normal sodium, and the degree of hyponatremia is a significant predictor for prognosis(3). CONCLUSIONS: SCLC is associated with large number of paraneoplastic syndromes which can also be the initial presentation in some cases. Ability to identify these syndromes especially in high risk population can lead to early diagnosis and might carry a better prognosis in some patients. Reference #1: Kanaji N, Watanabe N, Kita N, et al. Paraneoplastic syndromes associated with lung cancer. World J Clin Oncol. 2014;5(3):197-223 Reference #2: Maddison P, Gozzard P, Grainge MJ, Lang B. Long-term survival in paraneoplastic Lambert-Eaton myasthenic syndrome. Neurology. 2017 Apr 4. 88 (14):1334-1339 Reference #3: Wang W., Song Z., Zhang Y. Hyponatremia in small cell lung cancer is associated with a poorer prognosis. Translational Cancer Research. 2016;5(1):36–43. https://doi.org/10.3978/j.issn.2218-676X.2016.01.04 DISCLOSURES: No relevant relationships by alaa abu-sayf, source=Web Response No relevant relationships by Nitesh Gandhi, source=Web Response No relevant relationships by Sam Tirgari, source=Web Response

Abstract 4560: In situ multiplex analysis of regulatory and effector T cells in multiple tumor types

Abstract Immune-mediated rejection of cancer is prevented in part by the suppression of T effector (Teff) cells by regulatory T (Treg) cells. Favorable survival in numerous types of cancer has been associated with high Teff to Treg cells ratios as determined by flow cytometry or analysis of immunohistochemistry on serial sections. Multiplex immunofluorescence offers a technical advantage by allowing the detection of co-expression and spatial organization of up to 6 targets within a preserved tissue architecture on a single slide. We have designed a multiplex immunofluorescence protocol to identify human and murine Teff and Treg cells in situ. Human tissue microarrays of tumors in a range of tissues were investigated with a multiplex panel consisting of CD3/CD4/CD8/CD45RO/FoxP3/CD25. After multi-spectral acquisition, the T cell populations could be easily phenotyped and localized in all of the tissue types examined. The multiplex panel was then applied to non small cell lung carcinoma tumor and control tissues. Treg and Teff populations were quantified. The approach presented here demonstrates the power of multiplex immunohistochemistry in the identification and quantification of multiple immune cell populations on a single tissue section and the potential application of this method in both preclinical and clinical studies. Citation Format: Elena Baranova, Maroua Tliba, Manon Motte, Naomi Defort, Amanda Finan-Marchi, Domenico Lazzaro, Fanny Estermann, Jean-Philippe Coton, Renaud Burrer. In situ multiplex analysis of regulatory and effector T cells in multiple tumor types [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4560.

Abstract 3932: Metabolic biomarkers predict the sensitivity to phosphatidylinositol 3-kinase pathway inhibitor in small-cell lung carcinoma

Abstract Comprehensive genomic analysis has revealed that the PI3K/AKT/mTOR pathway is a feasible therapeutic target in small-cell lung carcinoma (SCLC). However, biomarkers to identify patients likely to benefit from inhibitors of this pathway have not been identified. Here we show that metabolic features determine sensitivity to the PI3K/mTOR dual inhibitor gedatolisib in SCLC cells. We analyzed the phosphatidyl lipid profile including the acyl groups of 11 SCLC cell lines using electrospray ionization mass spectrometry. We found that a specific phosphatidylinositol (3,4,5)-triphosphate (PIP3) subspecies lipid product, PIP3 (38:4), is predictive in assessing sensitivity to gedatolisib. We generated a large-scale metabolomic dataset for 28 SCLC cell lines. Notably, we found that higher amounts of purine-related aqueous metabolites such as hypoxanthine led to resistance to PI3K pathway inhibition. The levels of the mRNA encoding hypoxanthine phosphoribosyl transferase 1 (HPRT1), a key component of the purine salvage pathway, differed significantly between SCLC cells sensitive or resistant to gedatolisib. Loss of HPRT1 in SCLC cells decreased cellular proliferation in the presence of gedatolisib compared with a control. Further, complementation with purine metabolites could reverse the vulnerability to targeting of the PI3K pathway in SCLC cells normally sensitive to gedatolisib. These results indicate that the mechanism of resistance to PI3K pathway inhibitors is mediated by activation of the purine salvage pathway, which supplies purine resources for nucleotide biosynthesis. Metabolic profiles of clinical samples of SCLC revealed that purine-related metabolites were higher in SCLC tumor tissues, suggesting that higher amounts of purine-related aqueous metabolites might be characteristic of SCLC biology. Metabolomics is a powerful approach for identifying novel therapeutic biomarkers applicable to SCLC treatment. Citation Format: Shigeki Umemura, Hideki Makinoshima, Genichiro Ishii, Takehiko Sasaki, Hiroyasu Esumi, Koichi Goto, Katsuya Tsuchihara. Metabolic biomarkers predict the sensitivity to phosphatidylinositol 3-kinase pathway inhibitor in small-cell lung carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3932.

Immunohistochemical and Image Analysis-Based Study Shows That Several Immune Checkpoints are Co-expressed in Non-Small Cell Lung Carcinoma Tumors.

The understanding of immune checkpoint molecules' co-expression in non-small cell lung carcinoma (NCLC) is important to potentially design combinatorial immunotherapy approaches. We studied 225 formalin-fixed, paraffin-embedded tumor tissues from stage I-III NCLCs - 142 adenocarcinomas (ADCs) and 83 squamous cell carcinomas (SCCs) - placed in tissue microarrays. Nine immune checkpoint markers were evaluated; four (programmed death ligand 1 [PD-L1], B7-H3, B7-H4, and indoleamine 2,3-dioxygenase 1 [IDO-1]) expressed predominantly in malignant cells (MCs) and five (inducible T cell costimulator, V-set immunoregulatory receptor, T-cell immunoglobulin mucin family member 3, lymphocyte activating 3, and OX40) expressed mostly in stromal tumor-associated inflammatory cells (TAICs). All markers were examined using a quantitative image analysis and correlated with clinicopathologic features, TAICs, and molecular characteristics. Using above the median value as positive expression in MCs and high density of TAICs expressing those markers, we identified higher expression of immune checkpoints in SCC than ADC. Common simultaneous expression by MCs was PD-L1+ B7-H3+ IDO-1 in ADC and PD-L1+ B7-H3, or B7-H3+ B7-H4, in SCC. TAICs expressing checkpoint were significantly higher in current smokers than in never smokers. Almost all the immune checkpoint markers showed positive correlation with TAICs expressing inflammatory cell markers. KRAS-mutant ADC specimens showed higher expression of PD-L1 in MCs and of B7-H3, T-cell immunoglobulin mucin family member 3, and IDO-1 in TAICs than wild type. Kaplan-Meier survival curves showed worse prognosis in ADC patients with higher B7-H4 expression by MCs. We found frequent immunohistochemical co-expression of immune checkpoints in surgically resected NCLC tumors and correlated with tumor histology, smoking history, tumor size, and the density of inflammatory cells and tumor mutational status.

Tumor heterogeneity in small cell lung cancer defined and investigated in pre-clinical mouse models.

Small cell lung carcinoma (SCLC) is a fast-growing, highly metastatic form of lung cancer. A major difference between SCLC and other forms of lung cancer is that SCLC tumors often respond well to chemotherapy initially; unfortunately, resistant tumors rapidly recur. In addition, despite a large number of clinical trials with a variety of therapeutic agents, little progress has been achieved in the past three decades in improving the survival of SCLC patients. These clinical observations indicate that SCLC tumors have a high degree of plasticity and rapid adaptability to changes in growth conditions. Here we consider recent evidence pointing to several levels of heterogeneity in SCLC that may explain the ability of these tumors to adjust to different microenvironment and therapeutics. In particular, we review new data pointing to the existence of several subpopulations of tumor cells that interact with each other to promote tumor growth. We also discuss how SCLC tumors that look similar at the histopathological level may actually represent distinct subtypes of tumors and how these differences impact the response to specific therapeutic agents. A better understanding of genetic and cellular heterogeneity will guide the development of personalized approaches to help SCLC patients.

ED07.02 The 2015 WHO Classification of Neuroendocrine Tumors

ED07.02 The 2015 WHO Classification of Neuroendocrine Tumors

Elucidating alternative pathways triggering small cell lung carcinoma tumor biology

In their recent perspective Ito et al . comprehensively reviewed the carcinogenesis of pure and combined small cell lung carcinoma (SCLC) (1) and we appreciate the explicit discussion of our article Meder et a l. “ NOTCH, ASCL1, p53 and RB alterations define an alternative pathway driving neuroendocrine and small cell lung carcinomas. ” (2).

Elucidating alternative pathways triggering small cell lung carcinoma tumor biology

Elucidating alternative pathways triggering small cell lung carcinoma tumor biology

Histopathological transformation to small-cell lung carcinoma in non-small cell lung carcinoma tumors.

Lung cancer is the principal cause of cancer-related death worldwide. The use of targeted therapies, especially tyrosine kinase inhibitors (TKIs), in specific groups of patients has dramatically improved the prognosis of this disease, although inevitably some patients will develop resistance to these drugs during active treatment. The most common cancer-associated acquired mutation is the epidermal growth factor receptor (EGFR) Thr790Met (T790M) mutation. During active treatment with targeted therapies, histopathological transformation to small-cell lung carcinoma (SCLC) can occur in 3-15% of patients with non-small-cell lung carcinoma (NSCLC) tumors. By definition, SCLC is a high-grade tumor with specific histological and genetic characteristics. In the majority of cases, a good-quality hematoxylin and eosin (H&E) stain is enough to establish a diagnosis. Immunohistochemistry (IHC) is used to confirm the diagnosis and exclude other neoplasia such as sarcomatoid carcinomas, large-cell carcinoma, basaloid squamous-cell carcinoma, chronic inflammation, malignant melanoma, metastatic carcinoma, sarcoma, and lymphoma. A loss of the tumor-suppressor protein retinoblastoma 1 (RB1) is found in 100% of human SCLC tumors; therefore, it has an essential role in tumorigenesis and tumor development. Other genetic pathways probably involved in the histopathological transformation include neurogenic locus notch homolog (NOTCH) and achaete-scute homolog 1 (ASCL1). Histological transformation to SCLC can be suspected in NSCLC patients who clinically deteriorate during active treatment. Biopsy of any new lesion in this clinical setting is highly recommended to rule out a SCLC transformation. New studies are trying to assess this histological transformation by noninvasive measures such as measuring the concentration of serum neuron-specific enolase.

Abstract PR04: Inflammatory responses within the lung tumor microenvironment correlate with oncogenic mutation and histologic subtype

Abstract Lung cancer is a heterogeneous disease comprised of multiple histologic subtypes that harbor disparate mutational landscapes. Small cell lung carcinoma (SCLC), in which RB1 and TP53 mutations are common, accounts for 10-20% of lung cancer diagnoses. Approximately half of non-small cell lung carcinoma cases are classified as lung adenocarcinomas (ADCA), in which KRAS, EGFR, and TP53 mutations are the predominant genetic drivers. Novel immunotherapeutic strategies have offered new hope for the management of ADCA and SCLC, but the clinical success of immunomodulatory agents will depend on a strong foundational knowledge of the cells that comprise the lung tumor microenvironment (TME) in these molecularly and histologically distinct diseases. We therefore sought to determine whether the host immune response to lung cancer is predicated, at least in part, by histologic and genetic differences, as such correlations would have important clinical ramifications. Using three mouse models of lung ADCA KrasLSL-G12D, KrasLSL-G12D;Trp53Fl/Fl, and EgfrL858R as well as the Rb1Fl/Fl;Trp53Fl/Fl model of SCLC, we show that SCLC and ADCA tumors exhibit unique immune cell composition. Lung specimens from tumor-bearing and control animals (n ≥ 5 per cohort) were harvested at multiple time points and subjected to histological assessment and comprehensive flow cytometric immunophenotyping. Tumor-associated inflammation was discernibly lower in SCLC compared to all ADCA models. Moreover, the leukocyte composition of SCLC was dominated by cells of the adaptive rather than innate arm of the host immune system, a finding subsequently validated in 2 human SCLC surgical specimens. We further identified key differences in leukocyte content of mouse ADCA that correlated with oncogenic mutation. Although Egfr-mutant cancers displayed robust myeloid cell recruitment, they failed to mount a CD8+ cellular immune response. In contrast, Kras-mutant tumors displayed significant expansion of multiple immune cell types, including CD8+ cells, regulatory T cells, IL17-producing lymphocytes, and myeloid cells. Although loss of Trp53 promoted malignancy, it had minimal effect on immune cell composition within the Kras TME. Pre-clinical in vivo investigations with immune checkpoint inhibitor compounds are currently being conducted to assess the importance of these distinct immune responses to tumor progression and survival. To determine whether the differential inflammatory responses observed in mice are clinically relevant, we conducted an immune profiling study of a large lung cancer patient cohort that included 55 ADCA specimens. Notably, patients with EGFR mutations (n = 5) exhibited fewer total CD8+ T cells, as well as decreased exhausted CD8+PD1+ and CD8+TIM3+ content, compared to all other ADCA cases, thereby substantiating the murine phenotype. Taken together, these findings establish a strong foundational knowledge of the immune cell contexture of lung ADCA and SCLC and suggest that molecular and histological traits shape the host immune response to cancer. This abstract is also presented as Poster A01. Citation Format: Stephanie E. Busch, Julia Kargl, Mark L. Hanke, Heather E. Metz, Kyoung-Hee Kim, A McGarry Houghton. Inflammatory responses within the lung tumor microenvironment correlate with oncogenic mutation and histologic subtype. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr PR04.