Inhibition Of Non-small Cell Lung Cancer Research Articles

Homoharringtonine promotes non-small-cell lung cancer cell death via modulating HIF-1α/ERβ/E2F1 feedforward loop.

Hypoxia conditions promote the adaptation and progression of non-small-cell lung cancer (NSCLC) via hypoxia-inducible factors (HIF). HIF-1α may regulate estrogen receptor β (ERβ) and promote the progression of NSCLC. The phytochemical homoharringtonine (HHT) exerts strong inhibitory potency on NSCLC, with molecular mechanism under hypoxia being elusive. The effects of HHT on NSCLC growth were determined by cell viability assay, colony formation, flow cytometry, and H460 xenograft models. Western blotting, molecular docking program, site-directed mutagenesis assay, immunohistochemical assay, and immunofluorescence assay were performed to explore the underlying mechanisms of HHT-induced growth inhibition in NSCLC. HIF-1α/ERβ signaling-related E2F1 is highly expressed and contributes to unfavorable survival and tumor growth. The findings in hypoxic cells, HIF-1α overexpressing cells, as well as ERβ- or E2F1-overexpressed and knockdown cells suggest that the HIF-1α/ERβ/E2F1 feedforward loop promotes NSCLC cell growth. HHT suppresses HIF-1α/ERβ/E2F1 signaling via the ubiquitin-proteasome pathway, which is dependent on the inhibition of the protein expression of HIF-1α and ERβ. Molecular docking and site-directed mutagenesis revealed that HHT binds to the GLU305 site of ERβ. HHT inhibits cell proliferation and colony formation and promotes apoptosis in both NSCLC cells and xenograft models. The formation of the HIF-1α/ERβ/E2F1 feedforward loop promotes NSCLC growth and reveals a novel molecular mechanism by which HHT induces cell death in NSCLC.

Unlocking therapeutic potential: IL-1β as a target in non-small cell lung cancer with oncogenic mutations—Prognostic and predictive insights.

8030 Background: Preclinical studies have demonstrated heterogeneity in interleukin-1β (IL-1β) expression and its potential implications in non-small cell lung cancer(NSCLC). The phase II CANTOS trial incidentally showed reduced lung cancer incidence and mortality with the IL-1β inhibitor canakinumab. However, the phase III CANOPY-1/2 trials failed to demonstrate survival benefit when combining canakinumab with chemo/immunotherapy. The impact of IL-1β inhibition in NSCLC with actionable mutations remains unknown. This study aims to evaluate the prognostic and predictive role of IL-1β in NSCLC and its potential as a target for combination therapy. Methods: 34,960 NSCLC tumors underwent next-gen sequencing of DNA (592-gene or whole exome) and RNA (whole transcriptome) at Caris Life Sciences (Phoenix, AZ). Tumors were stratified by IL-1β transcriptional expression quartiles (Q1: low expression and Q4: high expression). Quartiles were established within each subpopulation. Significance was calculated using chi-square, Fisher’s exact, or Mann-Whitney U test, with p-values adjusted for multiple comparisons (p < 0.05). Overall survival (OS) from either time of tissue collection to last contact or time on treatment (TOT) was estimated from insurance claims data using the Cox proportional hazards model to calculate hazard ratio (HR) and log-rank tests to calculate p-values. Results: In the entire cohort, low IL-1β expressors showed improved OS compared to high expressors (20.0 months (m) vs 17.3 m, HR 0.88, 95%CI 0.88-0.95, p < 0.0001). For NSCLC without driver mutations, IL-1β expression did not correlate with OS difference. IL-1β expression was positively associated with TP-53 mutations (Q4 76% vs Q1 57%), high TMB (Q4 44% vs Q1 37%) and PD-L1+ expression by IHC (Q4 67% vs Q1 44%), while negatively associated with mutations in KRAS(Q4 24% vs Q1 31%) , EGFR(Q4 8% vs Q1 14%) , ERBB2 (Q4 1% vs Q1 2%) , BRAF (Q4 4% vs Q1 5%) ,and STK11 (Q4 10% vs Q1 18%) (p < 0.05). In EGFR-mutant NSCLC, Q1 showed superior OS than Q4 (34.6 m vs 25.1 m, HR 0.79, 95% CI 0.68-0.92, p = 0.002). This survival benefit was amplified in adenocarcinoma (Q1 41.2 m vs Q4 27.1 m, HR 0.74, 95% CI 0.63-0.87, p < 0.001). For ALK fusion-positive NSCLC, low expressors demonstrated improved OS (Q1 63.4 m vs Q4 27.0 m, HR 0.53, 95% CI 0.37-0.76, p < 0.001). In KRAS-mutant adenocarcinoma, high expressors showed improved immune-checkpoint inhibitor (ICI) TOT (Q4 6.4 m vs Q1 5.4 m, HR 0.85, 95% CI 0.74-0.98, p = 0.026); however, this did not correlate with improved OS. Conclusions: Our study shows promising prognostic value of IL-1β expression in NSCLC, associating low expression with improved OS across NSCLC subtypes. IL-1β expression is closely linked to key driver mutations in NSCLC and may have predictive value for ICIs. The findings suggest the potential benefit of targeting IL-1β in high IL-1β expressing NSCLC with driver mutations.

Generating immunogenomic data-guided virtual patients using a QSP model to predict response of advanced NSCLC to PD-L1 inhibition

Generating realistic virtual patients from a limited amount of patient data is one of the major challenges for quantitative systems pharmacology modeling in immuno-oncology. Quantitative systems pharmacology (QSP) is a mathematical modeling methodology that integrates mechanistic knowledge of biological systems to investigate dynamics in a whole system during disease progression and drug treatment. In the present analysis, we parameterized our previously published QSP model of the cancer-immunity cycle to non-small cell lung cancer (NSCLC) and generated a virtual patient cohort to predict clinical response to PD-L1 inhibition in NSCLC. The virtual patient generation was guided by immunogenomic data from iAtlas portal and population pharmacokinetic data of durvalumab, a PD-L1 inhibitor. With virtual patients generated following the immunogenomic data distribution, our model predicted a response rate of 18.6% (95% bootstrap confidence interval: 13.3-24.2%) and identified CD8/Treg ratio as a potential predictive biomarker in addition to PD-L1 expression and tumor mutational burden. We demonstrated that omics data served as a reliable resource for virtual patient generation techniques in immuno-oncology using QSP models.

The Role of MET in Resistance to EGFR Inhibition in NSCLC: A Review of Mechanisms and Treatment Implications.

Utilizing targeted therapy against activating mutations has opened a new era of treatment paradigms for patients with advanced non-small cell lung cancer (NSCLC). For patients with epidermal growth factor (EGFR)-mutated cancers, EGFR inhibitors, including the third-generation tyrosine kinase inhibitor (TKI) osimertinib, significantly prolong progression-free survival and overall survival, and are the current standard of care. However, progression after EGFR inhibition invariably occurs, and further study has helped elucidate mechanisms of resistance. Abnormalities in the mesenchymal-epithelial transition (MET) oncogenic pathway have been implicated as common alterations after progression, with MET amplification as one of the most frequent mechanisms. Multiple drugs with inhibitory activity against MET, including TKIs, antibodies, and antibody-drug conjugates, have been developed and studied in advanced NSCLC. Combining MET and EGFR is a promising treatment strategy for patients found to have a MET-driven resistance mechanism. Combination TKI therapy and EGFR-MET bispecific antibodies have shown promising anti-tumor activity in early clinical trials. Future study including ongoing large-scale trials of combination EGFR-MET inhibition will help clarify if targeting this mechanism behind EGFR resistance will have meaningful clinical benefit for patients with advanced EGFR-mutated NSCLC.

LncRNA NEAT1 induces autophagy through the miR-128-3p/ADAM28 axis to suppress apoptosis of nonsmall-cell lung cancer.

This study aimed to identify the molecular mechanism underlying NEAT1 regulation of non-small-cell lung cancer (NSCLC) autophagy and apoptosis. The expression levels of NEAT1, miR-128-3p, and ADAM28 in NSCLC tissues and cells were examined using qRT-PCR. The relationships between NEAT1, miR-128-3p, and ADAM28 expression levels and prognosis of NSCLC patients were investigated using the Kaplan-Meier analysis method. The interactions between NEAT1, miR-128-3p, and ADAM28 were confirmed by dual-luciferase reporter assay or FISH assay. Cell proliferation and apoptosis were detected by CCK-8 and flow cytometry assays, respectively. Apoptosis and autophagy-related proteins Bax, cleaved caspase-3, cleaved caspase-9, Bcl-2, LC3, Beclin-1, and p62 were analyzed by western blotting. Finally, an in vivo NSCLC mouse xenograft model was established to confirm the in vitro data. We showed NEAT1 and ADAM28 expression levels were upregulated, while the miR-128-3p level was downregulated in NSCLC tissues and cells. NSCLC patients with high NEAT1 expression levels, low miR-128-3p levels, or high ADAM28 levels had significantly reduced overall survival times. Silencing of NEAT1 inhibited NSCLC cell autophagy and promoted apoptosis by sponging miR-128-3p. MiR-128-3p directly targeted ADAM28 and suppressed ADAM28 expression, which led to deactivation of the JAK2/STAT3 signaling pathway. Furthermore, ADAM28 overexpression attenuated miR-128-3p overexpression-induced apoptosis and autophagy inhibition in NSCLC by increasing the phosphorylation of JAK2 and STAT3. NEAT1 depletion or miR-128-3p overexpression inhibited autophagy and promoted apoptosis in vivo by suppressing ADAM28. In other word, silencing NEAT1 inhibited autophagy and then promoted NSCLC cell apoptosis by deactivating the JAK2/STAT3 signaling pathway through regulation of miR-128-3p/ADAM28 axis.

BRAF/MEK inhibition in NSCLC: mechanisms of resistance and how to overcome it.

Targeted therapy for oncogenic genetic alterations has changed the treatment paradigm of advanced non-small cell lung cancer (NSCLC). Mutations in the BRAF gene are detected in approximately 4% of patients and result in hyper-activation of the MAPK pathway, leading to uncontrolled cellular proliferation. Inhibition of BRAF and its downstream effector MEK constitutes a therapeutic strategy for a subset of patients with NSCLC and is associated with clinical benefit. Unfortunately, the majority of patients will develop disease progression within 1year. Preclinical and clinical evidence suggests that resistance mechanisms involve the restoration of MAPK signaling which becomes inhibition-independent due to upstream or downstream alterations, and the activation of bypass pathways, such as the PI3/AKT/mTOR pathway. Future research should be directed to deciphering the mechanisms of cancer cells' oncogenic dependence, understanding the tissue-specific mechanisms of BRAF-mutant tumors, and optimizing treatment strategies after progression on BRAF and MEK inhibition.

Abstract 3280: Combination of MYC and class IIa HDAC inhibition potentiates anti-tumor efficacy in non-small cell lung cancer

Abstract Lung cancer is the leading cause of cancer-related mortality among both men and women in the United States. Immune checkpoint blockade has emerged as a promising therapy for advanced non-small cell lung cancer (NSCLC); however, only a subset of patients responds to this treatment regimen. Therefore, combinatorial therapeutic strategies to enhance anti-tumor immunity and efficacy of immunotherapy are in urgent need. Our group and others have demonstrated the potential of MYC inhibition in NSCLC to render the tumor microenvironment (TME) more immune permissive by upregulating antigen presentation machinery and chemokines that recruit effector lymphocytes. We performed a dedicated reanalysis of published transcriptome data from two distinct cancer types, prostate and lung, which were treated with novel MYC inhibiting agents, MYCi975 and Omomyc, respectively. These data revealed augmentation of two class IIa histone deacetylases (HDACs), HDAC5 and HDAC9, upon MYC inhibition. In addition to the suggested interaction between MYC and Class IIa HDACs derived from our transcriptional analyses, class IIa HDACs have an established role in tumorigenesis, angiogenesis, and poor prognosis of cancer patients, thus implying that therapeutic benefits could be derived from dual inhibition of MYC and class IIa HDAC. Elucidation of the basal relationship between Class IIa HDACs and the immune microenvironment of NSCLC was derived through correlative analyses of TCGA Lung adenocarcinoma and squamous carcinoma RNA-seq data. These data revealed a conserved positive correlation across non-small cell lung cancer between class IIa HDAC RNA levels, Treg score, and Treg/CD8 ratio by immune deconvolution analysis. Evaluation of combinatorial treatment efficacy of MYCi plus Class IIa HDACi was undertaken using 19 NSCLC cell lines, which recapitulate the mutational and histological landscape of NSCLC. These data identified a genotype-driven drug synergy, wherein EGFR mutant cell lines presented as resistant, and Ras mutant cell lines presented as sensitive to our combination drug paradigm. In summary, we defined a positive association between Class IIa HDAC expression and Treg score in TCGA NSCLC samples, suggesting a possibility of immune-modulation via class IIa HDAC inhibition. Furthermore, we identified transcriptional augmentation of class IIa HDAC induced by MYC repression, which indicates a potential novel therapeutic opportunity. Finally, we determined that inhibition of class IIa HDACs potentiates MYC inhibitor-driven anti-tumor efficacy across a diverse set of NSCLC cell lines. Citation Format: Jina Park, Michelle Vaz, Ray-Whay C. Yen, Stephen B. Baylin, Michael J. Topper. Combination of MYC and class IIa HDAC inhibition potentiates anti-tumor efficacy in non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3280.

The Core Mechanism of Yiqi Yangjing Decoction Inhibiting Nonsmall-Cell Lung Cancer.

Background Yiqi Yangjing prescription (YQYJ) is a traditional Chinese medicine prescription used for treating lung cancer. It has a significant effect on enhancing efficacy, reducing toxic symptoms, and improving patients' physical well-being. The effective inhibitory effect on nonsmall-cell lung cancer (NSCLC) has been demonstrated in vitro and in vivo. However, the mechanism of action and the material basis still remain unclear. Methods In this study, we explored this mechanism using network pharmacology, after which we explored the pharmacodynamics and the action mechanism of YQYJ using cell viability evaluation, plate clone formation assay, flow cytometry, real-time quantitative PCR, and Western blot. Results The enrichment results showed that there were 50 active components and 68 core targets related to YQYJ inhibiting NSCLC, including quercetin, luteolin, gamatin, kaempferol, heat shock protein HSP 90-alpha (HSP90AA1), cyclin-dependent kinase 2 (CDK2), epidermal growth factor receptor (EGFR), signal transducer and activator of transcription 3 (STAT3), and others. Among them, quercetin and kaempferol revealed the best binding effect with core targets. Most importantly, YQYJ promoted A549 cells from the quiescent phase into the proliferative phase to enhance the sensitivity of A549 cells to YQYJ and inhibited the proliferation of A549 cells significantly (P < 0.05). The A549 cells were blocked in both S and G2/M phases while the apoptosis ratio was increased. The proliferation score of A549 cells treated with YQYJ was significantly reduced compared to A549 cells in the proliferative phase (P < 0.05). This regulatory effect was related to the expression regulation of HSP90AA1, CDK2, STAT3, and phosphor-STAT3 (p-STAT3) by YQYJ, kaempferol, and quercetin. Conclusion Our results suggested that the inhibition of NSCLC via YQYJ had multicomponent and multitarget characteristics. Its core mechanism is related to the regulation of the cell cycle, proliferation, and apoptosis of NSCLC. This study provides a direction and scientific basis for exploring the future mechanism of YQYJ for the treatment of NSCLC.

High levels of chromosomal aberrations negatively associate with benefit to checkpoint inhibition in NSCLC

BackgroundImmune checkpoint inhibitors (ICIs) targeting the programmed cell death 1/programmed death-ligand 1 axis have transformed the management of advanced non-small cell lung cancer (NSCLC). However, many patients do not benefit...

Transient receptor potential vanilloid 4 promotes the growth of non-small cell lung cancer by regulating Foxp3.

Transient receptor potential vanilloid 4 (TRPV4) participates in malignant tumor. However, the role of TRPV4 in non-small cell lung cancer (NSCLC) remains unclear. In this study, we demonstrated TRPV4 was upregulated in NSCLC tissues and NSCLC cell lines. TRPV4 level in the NSCLC patients and cell lines were detected, and its function was studied both in vivo and vitro. The level of TRPV4 showed a positive correlation with tumor size of NSCLC patients. Activation TRPV4 by agonist GSK1016790A promoted cell proliferation and decreased apoptosis in A549 cells, and these effects were enhanced when the cells have overexpressed TRPV4. Moreover, GSK1016790A induced inhibitory effects on apoptosis of A549 cells was impaired when GSK1016790A used together with TRPV4 selective antagonist HC-067047, or impaired when the cells have already downregulated TRPV4 expression by TRPV4 siRNA. In vivo study, pharmacological inhibition of TRPV4 prevented A549 cells transplanted tumor growth. It was showed Foxp3 level was significantly increased in the NSCLC tissues, and showed a positive correlation with the level of TRPV4. Deactivation of TRPV4 using TRPV4 siRNA or HC-067047 significantly reduced expression of Foxp3 in GSK1016790A treated NSCLC cells. Moreover, downregulation Foxp3 by transfection of Foxp3 siRNA significantly impaired TRPV4 induced NSCLC cells proliferations in vitro. Antitumor effects caused by TRPV4 inhibition in NSCLC might be attributed to the suppression of Foxp3 which induced subsequent cell apoptosis. Thus, pharmacological inhibition of TRPV4 may be a promising option for NSCLC treatment.

Integrating network pharmacology and experimental models to investigate the mechanisms of dihydroartemisinin in preventing NSCLC progression via mTOR/HIF-1α signaling

Advanced Non-small cell lung cancer (NSCLC) is the most common type of lung cancer with a poor prognosis. The anti-malaria compounds dihydroartemisinin (DHA) have shown to regulate multiple targets and signaling pathways in cancers, but a global view of its mechanism of action remains elusive. In present study, we integrated network pharmacology and in vitro and in vivo experimental models to investigate the mechanisms of DHA in preventing NSCLC proliferation. We first proved that DHA inhibits the growth of lung cancer via inducing cell apoptosis and cell cycle arrest, then we integrated information from publicly available databases to predict interactions between DHA and its potential targets in NSCLC, as well as the signaling pathways involved. In this way we identified 118 common targets of DHA and NSCLC, and further analyzed with the correlation between these targets by KEGG and GO analysis. Our data indicate that mTOR/HIF-1α signaling is one of potential critical pathways involved in DHA-induced tumor inhibition in NSCLC. Finally, the data from human and mouse lung cancer cell lines and in mouse Lewis lung cancer models showed that DHA does decrease the expression level of mTOR and HIF-1α which supported the potential roles of mTOR/HIF-1α Signaling in NSCLC and deserves further investigation.

Randomized phase III Trial of MEDI4736 (durvalumab) as concurrent and consolidative therapy or consolidative therapy alone for unresectable stage 3 NSCLC: A trial of the ECOG-ACRIN Cancer Research Group (EA5181).

TPS8584 Background: Platinum-based concurrent chemoradiation(CRT) followed by one year of the human immunoglobulin G1 kappa (IgG1κ) monoclonal antibody, durvalumab, which blocks the interaction of PD-L1 with its receptors PD-1 and CD80, is the standard of care for locally advanced, unresectable non-small cell lung cancer (NSCLC). Early studies have noted the feasibility of concomitant administration of radiotherapy and immune checkpoint inhibition in NSCLC. EA5181 will evaluate the use of concomitant durvalumab with chemo-radiotherapy for locally advanced NSCLC. Methods: EA5181 is a randomized, multi-center, phase III study for patients with unresectable Stage III NSCLC comparing the efficacy of CRT with concomitant durvalumab to CRT, followed by one year of durvalumab. Eligibility criteria include: an ECOG PS of 0-1, adequate pulmonary function (FEV1 and DLCO both &gt; 40%), no history of auto-immune disease and no past chemotherapy or RT for this lung cancer. Stratification factors include age, sex, stage, and planned concurrent chemotherapy type. Eligible patients with be randomized 1:1 to receive 60Gy RT (2Gy fractions) CRT and durvalumab (Arm A) or 60Gy CRT (Arm B). Investigators will be allowed to choose from three different chemotherapy options: cisplatin/etoposide q 28 days, Pemetrexed/cisplatin q 21 days, and weekly paclitaxel/Carboplatin. Arm A will use 750mg fixed of durvalumab (considered equivalent to 10mg/kg) on days 1, 11, and 21 of RT. Assuming no disease progression, patients in both arms will be followed by monthly (q28 days) fixed dose of 1500mg durvalumab for one year which will be given optimally within 14 days of radiation or when (non)hematologic toxicity is &lt; Grade 2. The primary endpoint is overall survival. Secondary endpoints include progression-free survival, incidence of local/distant progression and toxicity. The target sample size is 660 patients, anticipated to recruit over 55 months, with follow up for an additional 42 months. This provides approximately 82% power if the true hazard ratio for overall survival was 0.75 or less, with 2-sided alpha of 0.05, and assuming a median survival of 42.5 months in the control arm. The study was activated on 04/09/20 and has currently accrued 90 patients on 02/03/21. Clinical trial information: NCT04092283.

The Role of Anti-angiogenesis in the Treatment Landscape of Non-small Cell Lung Cancer - New Combinational Approaches and Strategies of Neovessel Inhibition.

Tumor progression depends primarily on vascular supply, which is facilitated by angiogenic activity within the malignant tissue. Non-small cell lung cancer (NSCLC) is a highly vascularized tumor, and inhibition of angiogenesis was projected to be a promising therapeutic approach. Over a decade ago, the first anti-angiogenic agents were approved for advanced stage NSCLC patients, however, they only produced a marginal clinical benefit. Explanations why anti-angiogenic therapies only show modest effects include the highly adaptive tumor microenvironment (TME) as well as the less understood characteristics of the tumor vasculature. Today, advanced methods of in-depth characterization of the NSCLC TME by single cell RNA sequencing (scRNA-Seq) and preclinical observations enable a detailed characterization of individual cancer landscapes, allowing new aspects for a more individualized inhibition of angiogenesis to be identified. Furthermore, the tumor vasculature itself is composed of several cellular subtypes, which closely interact with other cellular components of the TME, and show distinct biological functions such as immune regulation, proliferation, and organization of the extracellular matrix. With these new insights, combinational approaches including chemotherapy, anti- angiogenic and immunotherapy can be developed to yield a more target-oriented anti-tumor treatment in NSCLC. Recently, anti-angiogenic agents were also shown to induce the formation of high endothelial venules (HEVs), which are essential for the formation of tertiary lymphoid structures, and key components in triggering anti-tumor immunity. In this review, we will summarize the current knowledge of tumor-angiogenesis and corresponding anti-angiogenic therapies, as well as new aspects concerning characterization of tumor-associated vessels and the resulting new strategies for anti-angiogenic therapies and vessel inhibition in NSCLC. We will further discuss why anti-angiogenic therapies form an interesting backbone strategy for combinational therapies and how anti-angiogenic approaches could be further developed in a more personalized tumor-oriented fashion with focus on NSCLC.

Polyphyllin VI Induces Caspase-1-Mediated Pyroptosis via the Induction of ROS/NF-κB/NLRP3/GSDMD Signal Axis in Non-Small Cell Lung Cancer.

Trillium tschonoskii Maxim (TTM), a traditional Chinese medicine, has been demonstrated to have a potent anti-tumor effect. Recently, polyphyllin VI (PPVI), a main saponin isolated from TTM, was reported by us to significantly suppress the proliferation of non-small cell lung cancer (NSCLC) via the induction of apoptosis and autophagy in vitro and in vivo. In this study, we further found that the NLRP3 inflammasome was activated in PPVI administrated A549-bearing athymic nude mice. As is known to us, pyroptosis is an inflammatory form of caspase-1-dependent programmed cell death that plays an important role in cancer. By using A549 and H1299 cells, the in vitro effect and action mechanism by which PPVI induces activation of the NLRP3 inflammasome in NSCLC were investigated. The anti-proliferative effect of PPVI in A549 and H1299 cells was firstly measured and validated by MTT assay. The activation of the NLRP3 inflammasome was detected by using Hoechst33324/PI staining, flow cytometry analysis and real-time live cell imaging methods. We found that PPVI significantly increased the percentage of cells with PI signal in A549 and H1299, and the dynamic change in cell morphology and the process of cell death of A549 cells indicated that PPVI induced an apoptosis-to-pyroptosis switch, and, ultimately, lytic cell death. In addition, belnacasan (VX-765), an inhibitor of caspase-1, could remarkably decrease the pyroptotic cell death of PPVI-treated A549 and H1299 cells. Moreover, by detecting the expression of NLRP3, ASC, caspase-1, IL-1β, IL-18 and GSDMD in A549 and h1299 cells using Western blotting, immunofluorescence imaging and flow cytometric analysis, measuring the caspase-1 activity using colorimetric assay, and quantifying the cytokines level of IL-1β and IL-18 using ELISA, the NLRP3 inflammasome was found to be activated in a dose manner, while VX-765 and necrosulfonamide (NSA), an inhibitor of GSDMD, could inhibit PPVI-induced activation of the NLRP3 inflammasome. Furthermore, the mechanism study found that PPVI could activate the NF-κB signaling pathway via increasing reactive oxygen species (ROS) levels in A549 and H1299 cells, and N-acetyl-L-cysteine (NAC), a scavenger of ROS, remarkably inhibited the cell death, and the activation of NF-κB and the NLRP3 inflammasome in PPVI-treated A549 and H1299 cells. Taken together, these data suggested that PPVI-induced, caspase-1-mediated pyroptosis via the induction of the ROS/NF-κB/NLRP3/GSDMD signal axis in NSCLC, which further clarified the mechanism of PPVI in the inhibition of NSCLC, and thereby provided a possibility for PPVI to serve as a novel therapeutic agent for NSCLC in the future.

Circulating Tumor Cell PD-L1 Expression as Biomarker for Therapeutic Efficacy of Immune Checkpoint Inhibition in NSCLC.

Over the last decade, the immune checkpoint blockade targeting the programmed death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) axis has improved progression-free and overall survival of advanced non-small cell lung cancer (NSCLC) patients. PD-L1 tumor expression, along with tumor mutational burden, is currently being explored as a predictive biomarker for responses to immune checkpoint inhibitors (ICIs). However, lung cancer patients may have insufficient tumor tissue samples and the high bleeding risk often prevents additional biopsies and, as a consequence, immunohistological evaluation of PD-L1 expression. In addition, PD-L1 shows a dynamic expression profile and can be influenced by intratumoral heterogeneity as well as the immune cell infiltrate in the tumor and its microenvironment, influencing the response rate to PD-1/PD-L1 axis ICIs. Therefore, to identify subgroups of patients with advanced NSCLC that will most likely benefit from ICI therapies, molecular characterization of PD-L1 expression in circulating tumor cells (CTCs) might be supportive. In this review, we highlight the use of CTCs as a complementary diagnostic tool for PD-L1 expression analysis in advanced NSCLC patients. In addition, we examine technical issues of PD-L1 measurement in tissue as well as in CTCs.

Invitro study of the Polo-like kinase 1 inhibitor volasertib in non-small-cell lung cancer reveals a role for the tumor suppressor p53.

Polo‐like kinase 1 (Plk1), a master regulator of mitosis and the DNA damage response, is considered to be an intriguing target in the research field of mitotic intervention. The observation that Plk1 is overexpressed in multiple human malignancies, including non‐small‐cell lung cancer (NSCLC), gave rise to the development of several small‐molecule inhibitors. Volasertib, presently the most extensively studied Plk1 inhibitor, has been validated to efficiently reduce tumor growth in preclinical settings. Unfortunately, only modest antitumor activity against solid tumors was reported in clinical trials. This discrepancy prompted research into the identification of predictive biomarkers. In this study, we investigated the therapeutic effect of volasertib monotherapy (i.e., cytotoxicity, cell cycle distribution, apoptotic cell death, cellular senescence, and migration) in a panel of NSCLC cell lines differing in p53 status under both normal and reduced oxygen tension (<0.1% O2). A strong growth inhibitory effect was observed in p53 wild‐type cells (A549 and A549‐NTC), with IC 50 values significantly lower than those in p53 knockdown/mutant cells (A549‐920 and NCI‐H1975) (P < 0.001). While mitotic arrest was significantly greater in cells with nonfunctional p53 (P < 0.005), apoptotic cell death (P < 0.026) and cellular senescence (P < 0.021) were predominantly induced in p53 wild‐type cells. Overall, the therapeutic effect of volasertib was reduced under hypoxia (P < 0.050). Remarkably, volasertib inhibited cell migration in all cell lines tested (P < 0.040), with the exception of for the NCI‐H1975 p53 mutant cell line. In conclusion, our results show an important difference in the therapeutic effect of Plk1 inhibition in NSCLC cells with versus without functional p53. Overall, the p53 wild‐type cell lines were more sensitive to volasertib treatment, suggesting that p53 might be a predictive biomarker for Plk1 inhibition in NSCLC. Moreover, our results pave the way for new combination strategies with Plk1 inhibitors to enhance antitumor activity.

An Orally Active Galectin-3 Antagonist Inhibits Lung Adenocarcinoma Growth and Augments Response to PD-L1 Blockade.

A combination therapy approach is required to improve tumor immune infiltration and patient response to immune checkpoint inhibitors that target negative regulatory receptors. Galectin-3 is a β-galactoside-binding lectin that is highly expressed within the tumor microenvironment of aggressive cancers and whose expression correlates with poor survival particularly in patients with non-small cell lung cancer (NSCLC). To examine the role of galectin-3 inhibition in NSCLC, we tested the effects of galectin-3 depletion using genetic and pharmacologic approaches on syngeneic mouse lung adenocarcinoma and human lung adenocarcinoma xenografts. Galectin-3-/- mice developed significantly smaller and fewer tumors and metastases than syngeneic C57/Bl6 wild-type mice. Macrophage ablation retarded tumor growth, whereas reconstitution with galectin-3-positive bone marrow restored tumor growth in galectin-3-/- mice, indicating that macrophages were a major driver of the antitumor response. Oral administration of a novel small molecule galectin-3 inhibitor GB1107 reduced human and mouse lung adenocarcinoma growth and blocked metastasis in the syngeneic model. Treatment with GB1107 increased tumor M1 macrophage polarization and CD8+ T-cell infiltration. Moreover, GB1107 potentiated the effects of a PD-L1 immune checkpoint inhibitor to increase expression of cytotoxic (IFNγ, granzyme B, perforin-1, Fas ligand) and apoptotic (cleaved caspase-3) effector molecules. In summary, galectin-3 is an important regulator of lung adenocarcinoma progression. The novel galectin-3 inhibitor presented could provide an effective, nontoxic monotherapy or be used in combination with immune checkpoint inhibitors to boost immune infiltration and responses in lung adenocarcinoma and potentially other aggressive cancers. SIGNIFICANCE: A novel and orally active galectin-3 antagonist inhibits lung adenocarcinoma growth and metastasis and augments response to PD-L1 blockade.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/7/1480/F1.large.jpg.

TNF-driven adaptive response mediates resistance to EGFR inhibition in lung cancer.

Although aberrant EGFR signaling is widespread in cancer, EGFR inhibition is effective only in a subset of non-small cell lung cancer (NSCLC) with EGFR activating mutations. A majority of NSCLCs express EGFR wild type (EGFRwt) and do not respond to EGFR inhibition. TNF is a major mediator of inflammation-induced cancer. We find that a rapid increase in TNF level is a universal adaptive response to EGFR inhibition in NSCLC, regardless of EGFR status. EGFR signaling actively suppresses TNF mRNA levels by inducing expression of miR-21, resulting in decreased TNF mRNA stability. Conversely, EGFR inhibition results in loss of miR-21 and increased TNF mRNA stability. In addition, TNF-induced NF-κB activation leads to increased TNF transcription in a feed-forward loop. Inhibition of TNF signaling renders EGFRwt-expressing NSCLC cell lines and an EGFRwt patient-derived xenograft (PDX) model highly sensitive to EGFR inhibition. In EGFR-mutant oncogene-addicted cells, blocking TNF enhances the effectiveness of EGFR inhibition. EGFR plus TNF inhibition is also effective in NSCLC with acquired resistance to EGFR inhibition. We suggest concomitant EGFR and TNF inhibition as a potentially new treatment approach that could be beneficial for a majority of lung cancer patients.

O43 The effects and mechanisms of two main constituents from Glycyrrhiza uralensis Fisch-induced autophagy in non-small cell lung cancer

The Glycyrrhiza uralensis Fisch, one of the famous Chinese medicinal herbs, has been widely used in anti-cancer prescription. We found that glycerrhetinic acid (GA, triterpenoid) and licochalcone A (LCA, flavonoid), two primary constituents of Glycyrrhiza uralensis Fisch, induced cell proliferative inhibition, apoptosis, and autophagy in non-small cell lung cancer (NSCLC) A549 and NCI-H1299 cells. Combined treatment with chloroquine further enhanced GA- or LCA-induced expression of LC3-II and more red-fluorescent puncta than green ones were observed in GA- or LCA-treated cells with transfection of mRFP-EGFP-LC3, suggesting that GA and LCA induces autophagic flux in NSCLC cells. Inhibition of autophagy enhanced GA-induced cell proliferative inhibition and apoptosis in NSCLC cells. In contrast, LCA-induced cell proliferative inhibition and apoptosis were not significantly altered after autophagy inhibition in NSCLC cells. The JNK and IRE1 α were activated after incubation with GA. Pretreatment with the JNK inhibitor SP600125 or silencing of the JNK pathway by siRNA of JNK or c-jun decreased GA-induced autophagy. Moreover, the GA-induced JNK pathway activation and autophagy were decreased by IRE1α knockdown, suggesting that GA induces autophagy through activation of IRE1α-JNK/c-jun pathway. LCA increased the expression of CHOP, and knockdown of CHOP reversed LCA-induced autophagy, suggesting that LCA-induced autophagy is due to induction of CHOP expression. Collectively, both GA and LCA induced cell proliferative inhibition, apoptosis, and autophagy in NSCLC, and inhibition of autophagy might be an effective strategy to enhance the anti-NSCLC effects of Glycyrrhiza uralensis Fisch contained prescriptions.

Abstract 4037: High throughput kinase inhibitor screen reveals novel inhibitor combinations acting in synergy with TUBB3/βIII-tubulin suppression in non-small cell lung cancer

Abstract Background: Non-Small Cell Lung Cancer (NSCLC) survival rates remain dismal and this malignancy is poorly responsive to current therapy. The mechanisms contributing to this resistance phenotype and aggressive behavior of this disease are not well defined. TUBB3/βIII-tubulin is aberrantly expressed in NSCLC and its expression correlates negatively with disease free survival of patients. Our group has previously shown that βIII-tubulin plays a functional role in chemotherapy resistance and tumorigenesis in NSCLC via modulation of the PTEN/AKT signaling pathway1, 2. This study aimed to identify kinase inhibitors that synergize with βIII-tubulin inhibition in NSCLC using a high-throughput cell-based screen. Methods: A high-throughput cell-based screen of a kinase inhibitor library was performed against our previously described1, 2 NSCLC H460 cells, expressing either βIII-tubulin shRNA or control non-targeting shRNA. The primary screen consisted of a total of 210 kinase inhibitors tested at a single, fixed concentration and cell viability determined using the Alamar blue assay. Secondary screens were performed using a five point dose response. Further validation of the kinase inhibitors was performed against two independent NSCLC, H460 and A549 expressing either βIII-tubulin shRNA or control non-targeting shRNA. Results: A number of kinase inhibitors that act on key signalling cascades were identified to act in synergy with TUBB3/βIII-tubulin knockdown to inhibit NSCLC cell growth. Interestingly, several different inhibitors which target mTOR were identified as top candidates for acting in combination with βIII-tubulin knockdown to inhibit NSCLC cell growth. Treatment of cells with clinically approved mTOR inhibitors, Temsirolimus and Rapamycin, resulted in a significant decrease in cell viability in the βIII-tubulin knockdown cells compared to control. Notably, mTOR acts downstream of AKT signalling and further highlights a potential connection with βIII-tubulin and the AKT signal transduction cascade. Other kinase inhibitors that act on key signaling cascades including Amuvatinib-Multi Kinase Inhibitor (Flt3, Met, Kit, c-Ret &amp; PDGFR); Mubritinib-HER-2 inhibitor; and Neratinib HER2, EGFR, also acted in combination with βIII-tubulin knockdown to inhibit NSCLC cell growth. Conclusions: Our results suggest that clinically approved therapies designed to target mTOR combined with inhibition of TUBB3/βIII-tubulin may offer a novel therapeutic strategy for the treatment of NSCLC patients.