Non-small Cell Lung Cancer Xenograft Research Articles

A validated high-performance liquid chromatography-tandem mass spectrometry method for quantification of gefitinib and its main metabolites in xenograft mouse tumor: Application to a pharmacokinetics study.

Monitoring gefitinib and its metabolites may help to explore the underlying mechanisms of gefitinib resistance. The concentration of gefitinib and its metabolites in tumor tissues could influence its anticancer activities more than that in the plasma. In the present study, a rapid and specific HPLC-MS/MS method was developed and validated to simultaneously determine gefitinib, M387783, M523595, M537194 and M608236 in tumor tissues of H1975 human lung cancer xenografts of nude mice. The established HPLC-MS/MS method was validated for specificity, linearity, accuracy and precision, matrix effect and recovery, carryover and dilution integrity, and analyte stability. The standard curves were linear (r2 ≥ 0.99) over the range of 0.5-100 ng/mL for M608236 and 1-200 ng/mL for gefitinib, M523595 and M537194 as well as M387783. The accuracy ranged from -8.35 to 6.03% relative error; and the precision was <15% relative standard deviation. Recoveries (87.74-99.96%) and matrix effects (86.60-106.40%) were satisfactory in the biological matrix examined. Stability studies showed that the analytes were stable during the assay procedure and storage. Finally, the validated method was successfully applied to study the pharmacokinetics profiles for gefitinib and its metabolites in nonsmall cell lung cancer (NSCLC) xenograft mouse tumors. Meanwhile, MTT assay showed that gefitinib had a more powerful inhibitory effect than its four major metabolites in H1975 NSCLC cells. This validated HPLC-MS/MS method may be applied to help understand the mechanisms of gefitinib resistance in EGFR-mutant nonsmall cell lung cancer.

Abstract 4415: CDK4/6 inhibition with lerociclib (G1T38) delays acquired resistance to targeted therapies in preclinical models of non-small cell lung cancer

Abstract Tyrosine kinase inhibitors (TKIs) targeting oncogenes such as EGFR, ALK, or RET have dramatically improved anti-tumor efficacy in patients with non-small cell lung cancer (NSCLC). Despite the significant clinical benefit offered by these agents, tumor responses to single-agent TKIs nevertheless remain limited in their magnitude and duration. Here we investigate combination therapy approaches with lerociclib (G1T38), a selective, oral, and potential best-in-class inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6). Consistent with previous studies reporting frequent cell-cycle gene alterations in NSCLC, we show that lerociclib synergizes with TKIs targeting EGFR, ALK, and RET in lung cancer cell lines and enhances the efficacy of osimertinib and crizotinib in PDX models harboring EGFR or ALK mutations, respectively. Moreover, in a well-characterized murine xenograft model of EGFR-mutant NSCLC, seven days of treatment with a clinically-relevant dose of osimertinib (25 mg/kg p.o. QDx7) resulted in 60% complete tumor responses, versus 100% complete tumor responses in the osimertinib plus lerociclib (25 mg/kg osi + 100 mg/kg lero, p.o. QDx7) group. Strikingly, complete tumor responses in the combination group persisted through an additional 35 days (or more) of observation, by which time all tumors in the osimertinib monotherapy group had re-emerged - suggesting a role for lerociclib in extending the duration of antitumor response. Based on this result, we assessed the ability of lerociclib to delay the emergence of resistance by chronically treating NSCLC cell lines with TKI +/- lerociclib. These experiments revealed that combination treatment with lerociclib significantly delayed acquired TKI resistance in multiple NSCLC cell lines. The same result was achieved in vivo in an EGFR-mutant NSCLC xenograft model known to develop resistance to EGFR TKI therapy, wherein combination treatment with lerociclib delayed the outgrowth of osimertinib-resistant tumors. Studies to characterize the mechanism by which lerociclib delays TKI resistance in NSCLC are ongoing. Finally, we addressed whether combination therapy with lerociclib can treat TKI resistance after it develops. In EGFR-mutant NSCLC xenografts harboring MET amplification - one of the more common mechanisms of resistance observed to EGFR TKIs in the clinic - the combination of lerociclib plus osimertinib caused significant tumor growth inhibition (90%) compared to osimertinib monotherapy (34%) after 46 days of continuous daily dosing. Collectively, our results suggest a compelling rationale for utilizing lerociclib as a backbone therapy for multiple combination regimens in NSCLC. A phase 1b/2 clinical trial evaluating lerociclib plus osimertinib in EGFR-mutant NSCLC is ongoing (NCT03455829). Citation Format: Daniel M. Freed, Claire R. Hall, Jay C. Strum, Patrick J. Roberts. CDK4/6 inhibition with lerociclib (G1T38) delays acquired resistance to targeted therapies in preclinical models of non-small cell lung cancer [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 4415.

Abstract 2924: Evaluation of the pan-FGFR inhibitor AZD4547 with radiation in non-small cell lung cancer

Abstract Objective: The fibroblast growth factor receptors (FGFR) are commonly altered in non-small cell lung cancer (NSCLC), including high level of amplification of FGFR1 in lung squamous cell carcinoma. FGFR signaling may play a role in the response to radiation. We investigated the radiosensitizing effects of the selective tyrosine kinase inhibitor AZD4547 in a NSCLC model using cell lines and tumor xenografts. Methods: A panel of six NSCLC cell lines were screened for FGFR1/2 DNA amplification, RNA expression, and protein expression. All cells were assessed for in vitro response to AZD4547. Immunoblots were used to examine the effect of AZD4547 on downstream signaling proteins. Apoptosis was measured by Annexin V staining and autophagy with acridine orange assay. Radiation clonogenic survival assays and xenograft growth delays experiments were performed to investigate radiosensitization. In vivo mechanistic studies were conducted using immunohistochemistry. Results: Cell lines demonstrated varying degree of FGFR1/2 RNA and protein expression. In sensitive cell lines, AZD4547 inhibited p-MAPK in a time dependent manner. In vitro clonogenic survival assays showed robust radiosensitivity with AZD4547 in three out of six NSCLC cell lines. All three cell lines overexpressed FGFR1 and two of the cells had high FGFR1 copy number. There was no radiosensitization seen in an immortalized normal human bronchial epithelial cell line. A significant increase in autophagy and apoptosis was observed with combined radiation and AZD4547. Significant tumor growth delay was observed with the administration of radiation and AZD4547 compared to radiation or drug alone in two NSCLC xenograft tumor models. IHC analysis revealed modulation of FGFR-downstream signaling (p-Erk and p-S6) and proliferative (Ki67) and apoptotic markers (Cleaved Caspace 3). Conclusion: These findings suggest that AZD4547 can augment the response of radiation in NSCLC model systems. FGFR1 and FGFR2 expression may be a potential targets for radiosensitization in NSCLC. Additional studies are underway to understand the mechanism of radiosensitization. Citation Format: Margot Miller, Michael Fisher, Gopika Senthilkumar, Saakshi Kaushik, Lindsey Able, Sean Brennan, Gopal Iyer, Randall Kimple, Andrew M. Baschnagel. Evaluation of the pan-FGFR inhibitor AZD4547 with radiation in non-small cell lung cancer [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 2924.

Abstract 3512: AZD7648, a potent and selective inhibitor of DNA-PK, potentiates the activity of ionising radiation and doxorubicin in vitro and causes tumour regression in xenograft models

Abstract DNA-dependent kinase (DNA-PK) is a nuclear serine/threonine protein kinase complex that is a key component of the non-homologous end joining (NHEJ) process. DNA-PK plays an important role in the cellular response to DNA damage through the detection and repair of DNA double strand breaks (DSB). Cancer therapies such as ionising radiation (IR) or topoisomerase II inhibitors (doxorubicin) generate DSB which can be repaired by homologous recombination (HR) or non-homologous end-joining (NHEJ). It can therefore be hypothesised a DNA-PK inhibitor would potentiate the activity of these agents. We have developed a highly potent and selective inhibitor of DNA-PK, AZD7648, which inhibits IR-induced DNA-PK S2056 auto phosphoryalation with an IC50 = 92 nM in A549 non-small cell lung cancer (NSCLC) cells. AZD7648 is a potent radiosensitiser where treatment in combination with IR led to a concentration-dependent reduction of the colony survival capacity of A549 and H1299 NSCLC cells (DEF37 at 100 nM = 1.7 and 2.5, respectively). In A549 cells, AZD7648 (≥1 µM) in combination with 2Gy IR for 48 hours led to a significant accumulation of cells arrested in the G2/M of the cell cycle, a 4-fold increase in micronuclei formation, and 3-fold induction of γH2AX, pATM S1981 and 53BP1 foci formation compared with IR alone. AZD7648 was also found to combine synergistically with doxorubicin in a panel of ovarian and triple negative breast cancer (TNBC) cell lines in cell growth inhibition assays when applying the Loewe additivity model (synergy scores 4 - 35). In vivo the combination of AZD7648 with IR (5x 2Gy) induced tumour regression in H1299 and A549 NSCLC xenografts in a dose-dependent manner (84 and 11% regression respectively), while monotherapy treatment only achieved tumour growth inhibition. In these two models the increased activation by IR of three primary DNA-PK pharmacodynamic markers, pDNAPK (S2056), pRPA32 (S4/8) and γH2AX, was inhibited by AZD7648 treatment (70-90% inhibition 2 h after IR + AZD7648). Similarly, liposomal doxorubicin (2.5 mg/kg weekly) in combination with AZD7648 (37.5 mg/kg bid) induced tumour regressions in the BT474c ER+ breast cancer xenograft model and in a TNBC PDX model (63% and 33% regression respectively), while monotherapy treatments only achieved tumour growth inhibition. These data confirm that DNA-PK inhibition with AZD7648 enhances the efficacy of a range of DSB inducing agents in vitro and in vivo, providing a clear rationale for its clinical investigation. Citation Format: Jacqueline H. Fok, Antonio Ramos-Montoya, Neil James, Mercedes Vazquez-Chantada, Valeria Follia, Ankur Karmokar, Anna Staniszewska, Lenka Oplustil O’Connor, Emma Dean, Simon J. Hollingsworth, Barry R. Davies, Elaine B. Cadogan. AZD7648, a potent and selective inhibitor of DNA-PK, potentiates the activity of ionising radiation and doxorubicin in vitro and causes tumour regression in xenograft models [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 3512.

Monitoring the Response of PD-L1 Expression to Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Nonsmall-Cell Lung Cancer Xenografts by Immuno-PET Imaging.

Accumulating evidence has suggested that the tumor microenvironment of nonsmall-cell lung cancer (NSCLC) may be impacted by chemotherapy, radiotherapy, or epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). PD-L1 is an important biomarker in the tumor microenvironment that can predict patient response to immunotherapies. Therefore, it is highly desirable to achieve a real-time, noninvasive assessment of PD-L1 expression, which can provide critical information for recruiting patients as well as monitoring therapeutic efficacy. We herein studied the EGFR-TKI-induced effects on PD-L1 levels in NSCLC tumor models using immuno-PET imaging with 89Zr-Df-KN035, an imaging tracer previously established by our group. A549 human NSCLC xenografts were established in BALB/c nude mice and treated with different doses of an EGFR-TKI gefitinib. PET imaging with 89Zr-Df-KN035 was performed before and after the treatment to evaluate PD-L1 expression, which was further verified by immunohistochemical staining. Our results demonstrate that 89Zr-Df-KN035 can specifically evaluate PD-L1 levels in NSCLC tumor models. Compared to the untreated control, the high dose of gefitinib inhibited tumor growth and lowered the tumor uptake of 89Zr-Df-KN035. In comparison, the low dose of gefitinib did not affect tumor growth, although the extensive tumor necrosis also led to the lower uptake of 89Zr-Df-KN035. In conclusion, our results demonstrate that immuno-PET imaging with 89Zr-Df-KN035 is a promising tool to noninvasively monitor PD-L1 expression in NSCLC treated with EGFR-TKIs and can be used to optimize treatment plans for immunotherapy.

High-affinity peptide ligand LXY30 for targeting \u03b13\u03b21 integrin in non-small cell lung cancer

Backgroundα3β1 integrin is a promising cancer biomarker and drug target. We previously identified a 9-amino-acid cyclic peptide LXY30 for detecting α3β1 integrin on the surface of live tumor cells. This study was undertaken to characterize LXY30 in the detection, cellular function, imaging, and targeted delivery of in vitro and in vivo non-small cell lung cancer (NSCLC) models.MethodsThe whole-cell binding assay was performed by incubating NSCLC cells, extracellular vesicles (EVs), and peripheral blood mononuclear cells (PBMCs) with TentaGel resin beads coated with LXY30. In this study, we defined the nanosize EVs as exosomes, which were characterized by flow cytometry, transmission electron microscopy, dynamic light scattering, and Western blots. The function of LXY30 was determined by modulating the epidermal growth factor receptor (EGFR) signaling pathway by growth inhibition and Western blots. For in vivo biodistribution, mice bearing subcutaneous and intracranial NSCLC xenograft tumors were administrated intraveneously with LXY30-biotin/streptavidin-Cy5.5 complex and then analyzed for in vivo and ex vivo optical imaging and histopathology.ResultsWe showed that LXY30 specifically and sensitively detected α3β1 integrin-expressing NSCLC cells and tumor-derived exosomes. Tumor DNA isolated from LXY30-enriched plasma exosomes might be used to detect driver oncogenic mutations in patients with metastatic NSCLC. LXY30 only enriches tumor cells but not neutrophils, macrophages, or monocytes in the malignant pleural effusion of NSCLC patients for detecting genomic alterations by next-generation sequencing. LXY30 detected increased α3β1 integrin expression on the EGFR-mutant NSCLC cells with acquired resistance to erlotinib compared to parental erlotinib-sensitive EGFR-mutant NSCLC cells. We further showed that LXY30 modulated the EGFR signaling pathway independently from another peptide ligand LXW64 targeting αvβ3 integrin in erlotinib-resistant, EGFR-mutant H1975 cells. Analysis of The Cancer Genome Atlas (TCGA) revealed high α3 integrin expression was associated with poor prognosis in lung squamous cell carcinoma. LXY30-biotin/streptavidin-Cy5.5 complex had higher uptakes in the subcutaneous and intracranial xenografts of various α3β1 integrin-expressing lung adenocarcinoma and patient-derived lung squamous cell carcinoma xenografts while sparing the surrounding normal tissues.ConclusionLXY30 is a promising peptide for the cancer diagnosis and in vivo targeted delivery of imaging agents and cancer drugs in NSCLC, independent of histology and tumor genotype.

Subcellular compartmentalization of PKM2 identifies anti-PKM2 therapy response in vitro and in vivo mouse model of human non-small-cell lung cancer.

Pyruvate kinase M2 (PKM2) is an alternatively spliced variant, which mediates the conversion of glucose to lactate in cancer cells under normoxic conditions, known as the Warburg effect. Previously, we demonstrated that PKM2 is one of 97 genes that are overexpressed in non-small-cell lung cancer (NSCLC) cell lines. Herein, we demonstrate a novel role of subcellular PKM2 expression as a biomarker of therapeutic response after targeting this gene by shRNA or small molecule inhibitor (SMI) of PKM2 enzyme activity in vitro and in vivo. We examined two established lung cancer cell lines, nine patients derived NSCLC and three normal lung fibroblast cell lines for PKM2 mRNA, protein and enzyme activity by RT-qPCR, immunocytochemistry (ICC), and Western blot analysis. All eleven NSCLC cell lines showed upregulated PKM2 enzymatic activity and protein expression mainly in their cytoplasm. Targeting PKM2 by shRNA or SMI, NSCLC cells showed significantly reduced mRNA, enzyme activity, cell viability, and colony formation, which also downregulated cytosolic PKM2 and upregulated nuclear enzyme activities. Normal lung fibroblast cell lines did not express PKM2, which served as negative controls. PKM2 targeting by SMI slowed tumor growth while gene-silencing significantly reduced growth of human NSCLC xenografts. Tumor sections from responding mice showed >70% reduction in cytoplasmic PKM2 with low or undetectable nuclear staining by immunohistochemistry (IHC). In sharp contrast, non-responding tumors showed a >38% increase in PKM2 nuclear staining with low or undetectable cytoplasmic staining. In conclusion, these results confirmed PKM2 as a target for cancer therapy and an unique function of subcellular PKM2, which may characterize therapeutic response to anti-PKM2 therapy in NSCLC.

LOXL1 Is Regulated by Integrin α11 and Promotes Non-Small Cell Lung Cancer Tumorigenicity.

Integrin α11, a stromal collagen receptor, promotes tumor growth and metastasis of non-small cell lung cancer (NSCLC) and is associated with the regulation of collagen stiffness in the tumor stroma. We have previously reported that lysyl oxidase like-1 (LOXL1), a matrix cross-linking enzyme, is down-regulated in integrin α11-deficient mice. In the present study, we investigated the relationship between LOXL1 and integrin α11, and the role of LOXL1 in NSCLC tumorigenicity. Our results show that the expression of LOXL1 and integrin α11 was correlated in three lung adenocarcinoma patient datasets and that integrin α11 indeed regulated LOXL1 expression in stromal cells. Using cancer-associated fibroblast (CAF) with either a knockdown or overexpression of LOXL1, we demonstrated a role for LOXL1 in collagen matrix remodeling and collagen fiber alignment in vitro and in vivo in a NSCLC xenograft model. As a consequence of collagen reorganization in NSCLC tumor stroma, we showed that LOXL1 supported tumor growth and progression. Our findings demonstrate that stromal LOXL1, under regulation of integrin α11, is a determinant factor of NSCLC tumorigenesis and may be an interesting target in this disease.

XPO1 inhibitor KPT-330 synergizes with Bcl-xL inhibitor to induce cancer cell apoptosis by perturbing rRNA processing and Mcl-1 protein synthesis

XPO1 (exportin1) mediates nuclear export of proteins and RNAs and is frequently overexpressed in cancers. In this study, we show that the orally bioavailable XPO1 inhibitor KPT-330 reduced Mcl-1 protein level, by which it synergized with Bcl-xL inhibitor A-1331852 to induce apoptosis in cancer cells. KPT-330/A-1331852 combination disrupted bindings of Mcl-1 and Bcl-xL to Bax, Bak, and/or Bim, elicited mitochondrial outer membrane permeabilization, and triggered apoptosis. KPT-330 generally mitigated mRNA expression and protein synthesis rather than mRNA nuclear export or protein stability of Mcl-1. KPT-330 inhibited mTORC1/4E-BP1 and Mnk1/eIF4E axes, which disrupted the eIF4F translation initiation complex but was dispensable for Mcl-1 reduction and KPT-330/A-1331852 combination-induced apoptosis. Mature rRNAs are integral components of the ribosome that determines protein synthesis ability. KPT-330 impeded nucleolar rRNA processing and reduced total levels of multiple mature rRNAs. Reconstitution of XPO1 by expressing degradation-resistant C528S mutant retained rRNA amount, Mcl-1 expression, and Bcl-xL inhibitor resistance upon KPT-330 treatment. KPT-330/A-1331852 combination suppressed growth and enhanced apoptosis of non-small cell lung cancer xenografts. Therefore, we clarify the reason of apoptosis resistance of cancer cells to XPO1 inhibition and develop a potential strategy for treating solid tumors.

Elevated Heme Synthesis and Uptake Underpin Intensified Oxidative Metabolism and Tumorigenic Functions in Non–Small Cell Lung Cancer Cells

Tumors of human non-small cell lung cancer (NSCLC) are heterogeneous but exhibit elevated glycolysis and glucose oxidation relative to benign lung tissues. Heme is a central molecule for oxidative metabolism and ATP generation via mitochondrial oxidative phosphorylation (OXPHOS). Here, we showed that levels of heme synthesis and uptake, mitochondrial heme, oxygen-utilizing hemoproteins, oxygen consumption, ATP generation, and key mitochondrial biogenesis regulators were enhanced in NSCLC cells relative to nontumorigenic cells. Likewise, proteins and enzymes relating to heme and mitochondrial functions were upregulated in human NSCLC tissues relative to normal tissues. Engineered heme-sequestering peptides (HSP) reduced heme uptake, intracellular heme levels, and tumorigenic functions of NSCLC cells. Addition of heme largely reversed the effect of HSPs on tumorigenic functions. Furthermore, HSP2 significantly suppressed the growth of human NSCLC xenograft tumors in mice. HSP2-treated tumors exhibited reduced oxygen consumption rates (OCR) and ATP levels. To further verify the importance of heme in promoting tumorigenicity, we generated NSCLC cell lines with increased heme synthesis or uptake by overexpressing either the rate-limiting heme synthesis enzyme ALAS1 or uptake protein SLC48A1, respectively. These cells exhibited enhanced migration and invasion and accelerated tumor growth in mice. Notably, tumors formed by cells with increased heme synthesis or uptake also displayed elevated OCRs and ATP levels. These data show that elevated heme flux and function underlie enhanced OXPHOS and tumorigenicity of NSCLC cells. Targeting heme flux and function offers a potential strategy for developing therapies for lung cancer. SIGNIFICANCE: These findings show that elevated heme availability due to increased heme synthesis and uptake causes intensified oxygen consumption and ATP generation, promoting tumorigenic functions and tumor growth in NSCLC. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/79/10/2511/F1.large.jpg.

ΜicroRNA‑889 plays a suppressive role in cell proliferation and invasion by directly targeting TAB1 in non‑small cell lung cancer.

MicroRNAs (miRNAs) are frequently reported to be aberrantly expressed in non‑small cell lung cancer (NSCLC) and are closely associated with aggressive tumor phenotypes. Hence, identification of cancer‑related miRNAs in NSCLC may be helpful for improving the cure rate of NSCLC treatments. miR‑889 has been demonstrated to be a novel cancer‑associated miRNA that is aberrantly expressed and plays an important role in esophageal squamous cell carcinoma and hepatocellular carcinoma. However, the exact functions and precise molecular mechanisms through which miR‑889 affects NSCLC progression are still unknown. In the present study, we report for the first time that miR‑889 expression is low in NSCLC tissues and cell lines. Clinically, low miR‑889 expression was found to be correlated with the TNM stage and distant metastasis in NSCLC patients. Functionally, miR‑889 overexpression suppressed the proliferation and invasiveness of NSCLC cells invitro and decreased NSCLC xenograft tumor growth in mice. Furthermore, TGF‑β‑activated kinase 1‑binding protein 1 (TAB1) was confirmed as a direct target gene of miR‑889 in NSCLC cells. TAB1 was revealed to be overexpressed in NSCLC tissue samples and was inversely correlated with miR‑889 levels. Moreover, a TAB1 knockdown had effects similar to that of miR‑889 overexpression, whereas restoration of TAB1 expression counteracted the actions of miR‑889 in NSCLC cells. Overall, the present results indicated that miR‑889 inhibits the aggressive behaviors of NSCLC by directly targeting TAB1 mRNA, thus highlighting the importance of the miR‑889/TAB1 pathway in the malignant progression of NSCLC.

AXL degradation in combination with EGFR-TKI can delay and overcome acquired resistance in human non-small cell lung cancer cells

Acquired resistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) has been a major obstacle in the treatment of non-small cell lung cancer (NSCLC) patients. AXL has been reported to mediate EGFR-TKIs. Recently, third generation EGFR-TKI osimertinib has been approved and yet its acquired resistance mechanism is not clearly understood. We found that AXL is involved in both gefitinib and osimertinib resistance using in vitro and in vivo model. In addition, AXL overexpression was correlated with extended protein degradation rate. We demonstrate targeting AXL degradation is an alternative route to restore EGFR-TKIs sensitivity. We confirmed that the combination effect of YD, an AXL degrader, and EGFR-TKIs can delay or overcome EGFR-TKIs-driven resistance in EGFR-mutant NSCLC cells, xenograft tumors, and patient-derived xenograft (PDX) models. Therefore, combination of EGFR-TKI and AXL degrader is a potentially effective treatment strategy for overcoming and delaying acquired resistance in NSCLC.

A novel antibody-drug conjugate, HcHAb18-DM1, has potent anti-tumor activity against human non-small cell lung cancer

Cluster of differentiation 147 (CD147), a transmembrane protein of the immunoglobulin superfamily, is a potential target of treatment against human non-small cell lung cancer (NSCLC). Although there have been exciting advances in epidermal growth factor receptor (EGFR)-targeted therapy for NSCLC in recent years, additional novel targeted agents are needed to improve the efficiency and to offer more options for patients. Antibody-drug conjugates (ADCs) utilize a chemical linker to conjugate cytotoxic drugs to a monoclonal antibody to maximize the delivery to target cells and minimize the delivery to other normal cells. The aim of this study was to prepare a novel anti-CD147 conjugate and examine the tumoricidal effect on NSCLC in vitro and in vivo.HcHAb18 was conjugated to the drug maytansinoid 1 (DM1) via a non-cleavable thioether linker (SMCC) to prepare HcHAb18-DM1 with an appropriate drug-antibody ratio (DAR). NSCLC cell lines expressing different levels of CD147 were tested in vitro to determine internalization, cell cycle arrest and cytotoxicity. In vivo efficacy and safety of HcHAb18-DM1 were evaluated in NSCLC xenograft mouse models.We found that HcHAb18-DM1 displayed an impressive potency in vitro and in vivo with a favorable safety profile. Upon binding to CD147, HcHAb18 could be internalized and delivered the payload DM1 to disturb mitotic spindle formation by microtubules. Target cells were arrested at G2/M phase and HcHAb18-DM1 exerted antiproliferative activity in vitro. Antigen-antibody binding and target cells with high growth rate were two integral prerequisites for exerting anti-tumor activity of HcHAb18-DM1. Therefore, we suggest HcHAb18-DM1 is a promising CD147-targeted therapeutic for NSCLC.

Baicalein Inhibits Orthotopic Human Non-Small Cell Lung Cancer Xenografts via Src/Id1 Pathway.

Non-small cell lung cancer (NSCLC) is one of the most lethal cancers worldwide. Inhibitor of differentiation 1 (Id1) is the member mostly linked to tumorigenesis in Id family and a potential molecular target in cancer therapy. In the current study, we established an orthotopic lung cancer model by injecting athymic nude mice with A549 cells and evaluated the antitumor effect of baicalein and expression of Id1-related proteins in vivo and in vitro. Micro-CT images showed that tumor volume in baicalein group was significantly reduced. Western blot analysis revealed that baicalein suppressed the expression of Id1 protein, epithelial-to-mesenchymal transition (EMT) related molecules (N-Cadherin, vimentin), and angiogenesis related protein (VEGF-A), accompanied by upregulation of epithelial markers (such as E-cadherin). In addition, phosphorylation of upstream molecular Src was significantly restrained after baicalein treatment. This study firstly demonstrates that baicalein inhibits tumor growth in orthotopic human NSCLC xenografts via targeting Src/Id1 pathway.

Afatinib-loaded immunoliposomes functionalized with cetuximab: A novel strategy targeting the epidermal growth factor receptor for treatment of non-small-cell lung cancer

Afatinib, a selective and irreversible inhibitor of tyrosine kinase, was approved for the treatment of advanced non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) overexpression in 2013. Cetuximab (CTX), an anti-EGFR monoclonal antibody, is co-administered with afatinib to improve efficacy. Unfortunately, dose-related adverse reactions caused by combination therapy have affected patient compliance, and have resulted in treatment discontinuation in severe cases. In the present study, afatinib was encapsulated in “liposomes” (LPs) to achieve longer circulation in the blood and an enhanced permeability-and-retention effect in tumors. Concomitantly, CTX was designed to bind to drug-loaded LPs to form “immuno-LPs” for tumor-cell selectivity and therapeutic activity. In vitro, the cellular internalization rate of immuno-LPs was significantly higher than that of LPs (p < 0.05). In vivo, a markedly increased area under the curve and prolonged terminal half-life were detected in rats injected with the two LP formulations, indicating that LP encapsulation protected afatinib from binding to hemoglobin to control the risk of idiosyncratic drug reactions. Compared with free afatinib and LPs, immuno-LPs exhibited strongly enhanced drug delivery and antitumor efficacy in an NSCLC xenograft model, with stronger tumor selectivity and potentially fewer side-effects. Hence, EGFR-targeting immuno-LPs appear to be promising for NSCLC treatment.

Cyclopamine tartrate, a modulator of hedgehog signaling and mitochondrial respiration, effectively arrests lung tumor growth and progression

Lung cancer remains the leading cause of cancer-related death, despite the advent of targeted therapies and immunotherapies. Therefore, it is crucial to identify novel molecular features unique to lung tumors. Here, we show that cyclopamine tartrate (CycT) strongly suppresses the growth of subcutaneously implanted non-small cell lung cancer (NSCLC) xenografts and nearly eradicated orthotopically implanted NSCLC xenografts. CycT reduces heme synthesis and degradation in NSCLC cells and suppresses oxygen consumption in purified mitochondria. In orthotopic tumors, CycT decreases the levels of proteins and enzymes crucial for heme synthesis, uptake, and oxidative phosphorylation (OXPHOS). CycT also decreases the levels of two regulators promoting OXPHOS, MYC and MCL1, and effectively alleviates tumor hypoxia. Evidently, CycT acts via multiple modes to suppress OXPHOS. One mode is to directly inhibit mitochondrial respiration/OXPHOS. Another mode is to inhibit heme synthesis and degradation. Both modes appear to be independent of hedgehog signaling. Addition of heme to NSCLC cells partially reverses the effect of CycT on oxygen consumption, proliferation, and tumorigenic functions. Together, our results strongly suggest that CycT suppress tumor growth in the lung by inhibiting heme metabolism and OXPHOS. Targeting heme metabolism and OXPHOS may be an effective strategy to combat lung cancer.

Simultaneous inhibition of PI3Kα and CDK4/6 synergistically suppresses KRAS-mutated non-small cell lung cancer.

ObjectiveActivating KRAS mutations are the most common drivers in the development of non-small cell lung cancer (NSCLC). However, unsuccess of treatment by direct inhibition of KRAS has been proven. Deregulation of PI3K signaling plays an important role in tumorigenesis and drug resistance in NSCLC. The activity of PI3Kα-selective inhibition against KRAS-mutated NSCLC remains largely unknown. MethodsCell proliferation was detected by sulforhodamine B assay. Cell cycle distribution and apoptosis were measured by flow cytometry. Cell signaling was assessed by Western blot and immunohistochemistry. RNA interference was used to down-regulate the expression of cyclin D1. Human NSCLC xenografts were employed to detect therapeutic efficacy in vivo. ResultsCYH33 possessed variable activity against a panel of KRAS-mutated NSCLC cell lines. Although CYH33 blocked AKT phosphorylation in all tested cells, Rb phosphorylation decreased in CYH33-sensitive, but not in CYH33-resistant cells, which was consistent with G1 phase arrest in sensitive cells. Combined treatment with the CDK4/6 inhibitor, PD0332991, and CYH33 displayed synergistic activity against the proliferation of both CYH33-sensitive and CYH33-resistant cells, which was accompanied by enhanced G1-phase arrest. Moreover, down-regulation of cyclin D1 sensitized NSCLC cells to CYH33. Reciprocally, CYH33 abrogated the PD0332991-induced up-regulation of cyclin D1 and phosphorylation of AKT in A549 cells. Co-treatment with these two drugs demonstrated synergistic activity against A549 and H23 xenografts, with enhanced inhibition of Rb phosphorylation.ConclusionsSimultaneous inhibition of PI3Kα and CDK4/6 displayed synergistic activity against KRAS-mutated NSCLC. These data provide a mechanistic rationale for the combination of a PI3Kα inhibitor and a CDK4/6 inhibitor for the treatment of KRAS-mutated NSCLC.

MiR-3607-3p suppresses non-small cell lung cancer (NSCLC) by targeting TGFBR1 and CCNE2.

Accumulating evidence indicates that miRNAs can be promising diagnostic and/or prognostic markers for various cancers. In this study, we identified a novel miRNA, miR-3607-3p, and its targets in non-small cell lung cancer (NSCLC). The expression of miR-3607-3p was measured and its correlation with patient prognosis was determined. Ectopic expression in NSCLC cells, xenografts, and metastasis models was used to evaluate the effects of miR-3607-3p on proliferation and migration of NSCLC. Luciferase assay and western blotting were performed to validate the potential targets of miR-3607-3p after preliminary screening by microarray analysis and computer-aided algorithms. We demonstrated that miR-3607-3p was downregulated in NSCLC tissues and that miR-3607-3p might act as an independent predictor for overall survival in NSCLC. Moreover, serum miR-3607-3p may be a novel and stable marker for NSCLC. We found that overexpression of miR-3607-3p inhibited cell proliferation, colony formation, migration and invasion, and hampered the cell cycle of NSCLC cell lines in vitro. Our results suggested that miR-3607-3p directly targets TGFBR1 and CCNE2. In accordance with in vitro studies, we confirmed that miR-3607-3p functions as a potent suppressor miRNA of NSCLC. We showed that miR-3607-3p agomir could reduce tumor growth and inhibit TGFBR1 and CCNE2 protein expression. Taken together, our findings indicate that miR-3607-3p can inhibit NSCLC cell growth and metastasis by targeting TGFBR1 and CCNE2 protein expression, and provide new evidence of miR-3607-3p as a potential non-invasive biomarker and therapeutic target for NSCLC.

Editor's Note: Grape Seed Proanthocyanidins Inhibit the Growth of Human Non-small Cell Lung Cancer Xenografts by Targeting Insulin-Like Growth Factor Binding Protein-3, Tumor Cell Proliferation, and Angiogenic Factors.

The editors are publishing this note to alert readers to a concern about this article (1): the IHC data presented in Fig. 5A in the two panels labeled “0.5% GSPs” appear to represent overlapping parts of the same image, even though they are labeled to represent different cell lines (A549 or H1299). Original data are not available for review.

KIAA1199 promotes invasion and migration in non-small-cell lung cancer (NSCLC) via PI3K-Akt mediated EMT.

KIAA1199 is often upregulated in cancer cells, including non-small-cell lung cancer (NSCLC). Although KIAA1199 is associated with aggressive tumor phenotype and poor survival in NSCLC, little is known about its functional role in NSCLC progression. Using archived clinical samples, we evaluated KIAA1199 messenger RNA (mRNA) and protein expression in NSCLC tissues and correlated with NSCLC clinicopathological characteristics as well as overall survival. Using NSCLC cell lines, KIAA1199 was either silenced using gene-specific shRNA or overexpressed to assess the impact on EMT signaling pathways. Finally, in a mouse xenograft NSCLC model, we determine the therapeutic potential of KIAA1199 repression. Our data showed that KIAA1199 was significantly upregulated in NSCLC tissues compared to adjacent normal tissues both at the mRNA (P < 0.001) and protein levels (P < 0.05). KIAA1199 overexpression is an independent prognostic marker for overall survival (HR = 1.833). In NSCLC cell lines, KIAA1199 expression directly influences the expression of EMT markers, EMT-inducing transcription factors (EMT-TFs), and EMT signaling molecules. Knocking down of KIAA1199 expression in the mouse NSCLC xenograft model significantly suppressed tumor growth and augmented the efficacy of chemotherapy (n = 5; P < 0.05). We conclude that KIAA1199 is not only a prognostic marker but a novel therapeutic target in NSCLC through regulating EMT signaling pathway. KEY MESSAGES: KIAA1199 overexpression is an independent prognostic marker in NSCLC. KIAA1199 expression directly influences the expression of EMT markers. KIAA1199 promotes invasion and migration in NSCLC via PI3K-Akt mediated EMT.