Non-small Lung Carcinoma Cell Lines Research Articles

Inhibition of SARS-CoV-2 Nsp9 ssDNA-Binding Activity and Cytotoxic Effects on H838, H1975, and A549 Human Non-Small Cell Lung Cancer Cells: Exploring the Potential of Nepenthes miranda Leaf Extract for Pulmonary Disease Treatment.

Carnivorous pitcher plants from the genus Nepenthes are renowned for their ethnobotanical uses. This research explores the therapeutic potential of Nepenthes miranda leaf extract against nonstructural protein 9 (Nsp9) of SARS-CoV-2 and in treating human non-small cell lung carcinoma (NSCLC) cell lines. Nsp9, essential for SARS-CoV-2 RNA replication, was expressed and purified, and its interaction with ssDNA was assessed. Initial tests with myricetin and oridonin, known for targeting ssDNA-binding proteins and Nsp9, respectively, did not inhibit the ssDNA-binding activity of Nsp9. Subsequent screenings of various N. miranda extracts identified those using acetone, methanol, and ethanol as particularly effective in disrupting Nsp9's ssDNA-binding activity, as evidenced by electrophoretic mobility shift assays. Molecular docking studies highlighted stigmast-5-en-3-ol and lupenone, major components in the leaf extract of N. miranda, as potential inhibitors. The cytotoxic properties of N. miranda leaf extract were examined across NSCLC lines H1975, A549, and H838, focusing on cell survival, apoptosis, and migration. Results showed a dose-dependent cytotoxic effect in the following order: H1975 > A549 > H838 cells, indicating specificity. Enhanced anticancer effects were observed when the extract was combined with afatinib, suggesting synergistic interactions. Flow cytometry indicated that N. miranda leaf extract could induce G2 cell cycle arrest in H1975 cells, potentially inhibiting cancer cell proliferation. Gas chromatography-mass spectrometry (GC-MS) enabled the tentative identification of the 19 most abundant compounds in the leaf extract of N. miranda. These outcomes underscore the dual utility of N. miranda leaf extract in potentially managing SARS-CoV-2 infection through Nsp9 inhibition and offering anticancer benefits against lung carcinoma. These results significantly broaden the potential medical applications of N. miranda leaf extract, suggesting its use not only in traditional remedies but also as a prospective treatment for pulmonary diseases. Overall, our findings position the leaf extract of N. miranda as a promising source of natural compounds for anticancer therapeutics and antiviral therapies, warranting further investigation into its molecular mechanisms and potential clinical applications.

Photochemical preparation, characterization and formation kinetics of riboflavin conjugated silver nanoparticles

Riboflavin conjugated silver nanoparticles (RF–AgNPs) have been synthesized by photoreduction of Ag+ ions and characterized by UV–visible, X-ray diffraction (XRD), FTIR spectroscopy, spectrofluorimetry, dynamic light scattering (DLS) and atomic force microscopy (AFM). The RF–AgNPs exhibit a typical surface plasmon resonance (SPR) peak at 422 nm due to the interaction of RF and AgNPs. FTIR studies indicate the appearance of an intense absorption peak at 2920 cm–1 due to the interaction of RF and Ag. AFM studies indicate that the RF–AgNPs are spherical and polydisperse in nature (57–73 nm), which nicely complement the hydrodynamic radii (57.9–72.2 nm) measured by DLS. None of the tested concentrations (1-250 µg mL−1) of RF–conjugated AgNPs show any adverse effect on normal mouse fibroblast and cancerous non-small lung carcinoma cell lines. At acidic pH (2.0–6.2) aggregation of RF–AgNPs occurs due to an increase in the ionic strength of the medium. The rates of formation of RF–AgNPs on UV and visible light irradiation have been determined in the pH range of 8.0–10.5 and at different concentrations of Ag+ ions. The photochemical formation of RF–AgNPs follows a biphasic first–order reaction probably due to the formation of AgNPs in the first phase (fast) and the adsorption of RF on AgNPs to yield RF–AgNPs in the second phase (slow).

In Silico and In Vitro Evaluations of Fluorophoric Thiazolo-[2,3-b]quinazolinones as Anti-cancer Agents Targeting EGFR-TKD.

Epidermal growth factor receptor tyrosine kinase domain (EGFR-TKD) plays a pivotal role in cellular signaling, growth, and metabolism. The EGFR-TKD is highly expressed in cancer cells and was endorsed as a therapeutic target for cancer management to overcome metastasis, cell proliferation, and angiogenesis. The novel thiazolo-[2,3-b]quinazolinones series were strategically developed by microwave-assisted organic synthesis and multi dominos reactions aimed to identify the potent thiazolo-[2,3-b]quinazolinone inhibitor against EGFR-TKD. This study explores the binding stability and binding strength of newly developed series via molecular docking, molecular dynamics simulation, and MM/PBSA and MM/GBSA calculations. The binding interaction was observed to be through the functional groups on aryl substituents at positions 3 and 5 of the thiazolo-[2, 3-b]quinazolinone scaffold. The methyl substituents at position 8 of the ligands had prominent hydrophobic interactions corroborating their bindings similar to the reference FDA-approved drug erlotinib in the active site. ADMET predictions reveal that derivatives 5ab, 5aq, and 5bq are drug-like and may be effective in in vitro study. Molecular dynamics simulation for 100ns of docked complexes revealed their stability at the atomistic level. The ΔGbinding of thiazolo-[2,3-b]quinazolinone was found to be 5ab - 22.45, 5aq - 22.23, and 5bq - 20.76 similar to standard drug, and erlotinib - 24.11kcal/mol was determined by MM/GBSA method. Furthermore, the anti-proliferative activity of leads of thiazolo-[2,3-b]quinazolinones (n = 3) was studied against breast cancer cell line (MCF-7) and non-small lung carcinoma cell line (H-1299). The highest inhibitions in cell proliferation were shown by 5bq derivatives, and the IC50 was found to be 6.5 ± 0.67µM against MCF-7 and 14.8µM against H-1299. The noscapine was also taken as a positive control and showed IC50 at higher concentrations 37 ± 1 against MCF-7 and 46.5 ± 1.2 against H-1299.

Brazilin Isolated from Caesalpina Sappan Wood Induces Intrinsic Apoptosis on A549 Cancer Cell Line by Increasing p53, caspase-9, and caspase-3.

Objective:Lung cancer is the leading cause of death among cancer patients. The majority of lung cancer is the Non-Small Lung Carcinoma (NSLC). This study evaluated the potency of brazilin isolated from Caesalpinia sappan wood to induce apoptosis on non-small lung carcinoma cell line, A549, by examining the expression of p53, caspase-9, and caspase-3.Methods:Brazilin was isolated from Caesalpinia sappan wood following a guided assay and it was determined by using Brazilin®SIGMA as standard. The activity of brazilin on the growth of A549 cell line was analysed by MTT assay and the apoptosis was evaluated by flowcytometer following Annexin V (FITC) and PI staining. The expression of p53, caspase-9, and caspase-3 was examined by immunocytochemistry. Result:The IC50 of brazilin on A549 cell line was 43µg/mL. Cell treatment with 20 µg/mL and 40 µg/mL of brazilin significantly increased early apoptosis (p<0.001). Cell treatment with 40 µg/mL of Brazilin significantly increased late apoptosis (p<0.001). Brazilin significantly increased the expression of p53, Caspase-9, and caspase-3 (p<0.001). Conclusion:This study showed evidence of the activity of brazilin to induce intrinsic apoptosis on a NSLC cell line A549.

Short-Chain Hydroxyl CoA Dehydrogenase Probably is the Central Player in DNA Replication and Glucose Consumption in Human Non-Small Lung Carcinoma Cell Line

: Hydroxyl CoA Dehydrogenase (HADH) is one of the key enzymes in fatty acid β-oxidation. Recently, Hydroxyl CoA Dehydrogenase gene mutation and knockdown were found to be correlated with hyperinsulinemia and central nervous system diseases. As the HADH is one of the critical enzymes in the β-oxidation pathway, the interconnection between HADH and tumorigenicity still is unclear. So, we used Short hairpin RNA (ShRNA) to knock down short-chain hydroxyl CoA dehydrogenase (HADHSC) in human non-small lung carcinoma cell line, H1299, followed by checking cell proliferation, DNA replication, and mRNA level of some the most essential enzymes in glycolysis cycle and Krebs. Cell proliferation was checked by comparing the cell numbers in knockdown and control cells. DNA replication in the H1299 cell line was studied after applying 5-ethynyl 2’-deoxyuridine (EDU) and 4’-6 diamidino-2-phenylindol (DAPI) DNA synthesis Assay. The data revealed a significant decrease in cell proliferation and DNA replication in the cells that the HADHSC was knocked down compared to the control cells. Besides, mRNA levels of the enzymes that needed adenosine triphosphate (ATP) for their activity were decreased abruptly. Furthermore, lactate dehydrogenase (LDHA) mRNA level decreased, and glucose uptake assay showed a tremendous decrease in glucose consumption by H1299 cells with HADHSC knockdown.

Abstract 6060: The transactivation domain of TWIST1 is required for TWIST1-induced aggressiveness in non-small cell lung cancer

Abstract Lung cancer is the most common cause of mortality by cancer. Non-small cell lung carcinoma (NSCLC) accounts for 80% of lung cancers. Although progresses has been realized, resistance to current treatments still remain high and the overall survival is a dismal ~16%. The high expression of TWIST1 in cancers strongly correlates with invasive, resistant, and metastatic cancers, and is attributed to the induction of the epithelial-mesenchymal transition phenotype. Additionally, TWIST1 antagonizes the induction of the oncogene (KrasG12D)-induced senescence in primary NSCLC tumor. As TWIST1 is a pleiotropic transcription factor essential for development, the targeting of the entire TWIST1 protein may cause unintended side effects. Dissecting what are the critical domains of TWIST1 and its crucial downstream transcriptional targets required for TWIST1-dependent radioresistance and pro-tumorigenicity would allow to decipher new therapeutic strategies. In this goal, we generated a transactivation-null TWIST1 mutant by mutation of phenylalanine at position 191 to glycine and aimed to characterize its functions. We generated mouse models utilizing a tetracycline-inducible gene expression system: in this model, treatment with doxycycline allows to control concomitant induction of KrasG12D oncogene expression (R) with TWIST1 (T)/Luciferase expression or with TWIST1F191G mutant (T-F191G)/Luciferase expression, specifically in the lung epithelium using the CCSP promoter-rtTA construct (C). TWIST1 expression in CRT model induced a more aggressive tumor progression and a shorter survival (median= 15,6 weeks) compared to CR model (median= 31 weeks). The expression of TWIST1F191G mutant in CRT-F191G model abrogates these effects (median= 26.7 weeks) showing the importance of the transactivation domain of TWIST1 to fulfill its pro-tumor progression functions. Next, the histological analysis of the lung tumor sections of these models shown that the expression of TWIST1 in CRT mice induced a higher positivity for Ki67 and a reduced positivity for Caspase3. CRT mice also present a decrease for p16 expression compared to CR mice reflecting TWIST1-induced OIS suppression. Additionally, the expression of TWIST1F191G mutant shown a similar profile to CR model potentially indicating a role of TWIST1 transactivation domain in the suppression of OIS. On the other hand, the expression of TWIST1 in NSCLC lines conferred a partial radiation resistance. We also observed that the expression of TWIST1 in AEF line conferred the same resistant profile while the expression of TWIST1F191G increased the sensitivity to radiation. Moreover, the CRT model also presented more resistance to 1 × 15Gy or 10 × 3Gy thoracic irradiation suggesting again that targeting TWIST1 transactivation function would confer a potential new important therapeutic option. Citation Format: Audrey Lafargue, Hailun Wang, Sivarajan T. Chettiar, Rajendra P. Gajula, Kekoa Taparra, Katriana Nugent, Phuoc T. Tran. The transactivation domain of TWIST1 is required for TWIST1-induced aggressiveness in non-small cell lung cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6060.

MEAK-7 Forms an Alternative mTOR Complex with DNA-PKcs in Human Cancer

SummaryMTOR associated protein, eak-7 homolog (mEAK-7), activates mechanistic target of rapamycin (mTOR) signaling in human cells through an alternative mTOR complex to regulate S6K2 and 4E-BP1. However, the role of mEAK-7 in human cancer has not yet been identified. We demonstrate that mEAK-7 and mTOR signaling are strongly elevated in tumor and metastatic lymph nodes of patients with non-small-cell lung carcinoma compared with those of patients with normal lung or lymph tissue. Cancer stem cells, CD44+/CD90+ cells, yield elevated mEAK-7 and activated mTOR signaling. mEAK-7 is required for clonogenic potential and spheroid formation. mEAK-7 associates with DNA-dependent protein kinase catalytic subunit isoform 1 (DNA-PKcs), and this interaction is increased in response to X-ray irradiation to regulate S6K2 signaling. DNA-PKcs pharmacologic inhibition or genetic knockout reduced S6K2, mEAK-7, and mTOR binding with DNA-PKcs, resulting in loss of S6K2 activity and mTOR signaling. Therefore, mEAK-7 forms an alternative mTOR complex with DNA-PKcs to regulate S6K2 in human cancer cells.

Targeting of BRM Sensitizes BRG1-Mutant Lung Cancer Cell Lines to Radiotherapy.

Targeting of epigenetic regulators as the chromatin remodeler SWI/SNF is proving to be a promising therapeutic strategy for individualized treatment of cancer patients. Here, we tested whether targeting one of the two mutually exclusive subdomains of the SWI/SNF complex BRM/SMARCA2 can sensitize specifically non-small cell lung carcinoma (NSCLC) cells with mutations in the other subunit BRG1/SMARCA4 toward ionizing radiation (IR). Knockdown of BRM with siRNA or shRNA and its consequences for radiation sensitivity as measured by clonogenic survival and plaque-monolayer control was studied in different NSCLC lines with or without BRG1 mutations and in primary fibroblasts. Furthermore, the effect on double-strand break (DSB) repair markers measured by immunofluorescence staining of 53BP1-, γ-H2AX-, and Rad51-foci was investigated. BRG1-mutated cell lines showed an increased surviving fraction compared with BRG1 proficient cells. Depletion of BRM (i) leads to a decreased proliferation rate and plating efficiency specifically in BRG1-mutated cells, (ii) specifically sensitized BRG1-mutant NSCLC cells toward IR as characterized by a survival reducing factor of 0.63 [95% confidence interval (CI), 0.57-0.69] in the dose range between 2 and 6 Gy, and (iii) decreased the tumor control doses after daily fractionation at 4 Gy in BRG1-mutant NSCLC cell lines A549 and H1299 in minimonolayers by 9.9% ± 1.3% and 13.6% ± 1.8%, respectively. In addition, an increase of residual Rad51-foci at 24 hours after irradiation in BRG1-mutant cells was demonstrated. Therefore, targeting of BRM in combination with radiotherapy is supposed to improve the therapeutic outcome of lung cancer patients harboring BRG1 mutations.The present study shows that the moderate radioresponsiveness of NSCLC cells with BRG1 mutations can be increased upon BRM depletion that is associated with a prolonged Rad51-foci prevalence at DNA DSBs.

Abstract 556: Oncogenic properties and response to HDAC inhibitor treatment of H1299 cells expressing GOF p53 mutants

Abstract The tumor suppressor p53 protein is mutated in over 50% of cancers. The most frequent mutations in p53, termed “hotspot” mutations, occur in the DNA binding domain of the p53 protein. These mutations not only remove normal p53 function but also convey additional oncogenic properties greater than loss of tumor suppressor activities associated with loss of wild-type (WT) p53 activities. With newly acquired oncogenic properties, mutations in the DNA binding domain of p53 are classified as gain of function (GOF) mutations. GOF p53 mutants can be subdivided into conformational mutations (e.g. R175H, H193Y) involving residues necessary for maintenance of structure and contact mutations (e.g. R248Q, R273H) involving resides necessary for DNA interaction. Cancer cells bearing a GOF p53 mutation increase metastasis with application of histone deacetylase inhibitors (HDACi). This uncharacterized pro-oncogenic GOF p53 property is of clinical relevance as HDACi are FDA approved for hematological cancers but have failed in clinical trials for solid tumors. To explore this hypothesis, metastatic capacity and proliferation rates of common GOF p53 mutations were assessed with and without HDACi treatment and in the presence or absence of specific inhibitors of target GOF p53. The p53-null, H1299 non-small cell lung carcinoma line was transfected with GOF p53 mutants and WT p53 using a tetracycline inducible expression system. Inducible expression of stable subclones was varified by immunofluorescence and western blot. Proliferation rate was measured by incorporation of EdU and metastatic capacity was assessed by measuring MMP activity and migration assays with and without HDACi treatment. Specific GOF p53 mutations possess a subset of the oncogenic properties of the entire GOF p53 class. Data suggest that the GOF p53 mutants display differing rates of proliferation with the R175H mutation exhibiting the highest rate. Application of NSC319726 significantly decreases the proliferation rate and appears to successfully refold the R175H mutant to a WT conformation. The R248Q mutation exhibited morphological change suggestive of the epithelial to mesenchymal transition associated with increased metastatic capacity. Preliminary data suggest that HDACi affect among these cell lines in conjunction with NSC 319726 and SCH 529074 treatment. In conclusion, HDACi treatment may be contraindicated while treatment with HDACi may have great benefit in tumors which are WT or null for p53 protein expression. Citation Format: Brianna Flores, Elizabeth E. Hull. Oncogenic properties and response to HDAC inhibitor treatment of H1299 cells expressing GOF p53 mutants [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 556.

RASA1 and NF1 are Preferentially Co-Mutated and Define A Distinct Genetic Subset of Smoking-Associated Non-Small Cell Lung Carcinomas Sensitive to MEK Inhibition.

Purpose: Ras-GTPase-activating proteins (RasGAP), notably NF1 and RASA1, mediate negative control of the RAS/MAPK pathway. We evaluated clinical and molecular characteristics of non-small cell lung carcinoma (NSCLC) with RASA1 mutations in comparison with NF1-mutated cases.Experimental Design: Large genomic datasets of NSCLC [MSK-IMPACT dataset at MSKCC (n = 2,004), TCGA combined lung cancer dataset (n = 1,144)] were analyzed to define concurrent mutations and clinical features of RASA1-mutated NSCLCs. Functional studies were performed using immortalized human bronchial epithelial cells (HBEC) and NSCLC lines with truncating mutations in RASA1, NF1, or both.Results: Overall, approximately 2% of NSCLCs had RASA1-truncating mutations, and this alteration was statistically, but not completely, mutually exclusive with known activating EGFR (P = 0.02) and KRAS (P = 0.02) mutations. Unexpectedly, RASA1-truncating mutations had a strong tendency to co-occur with NF1-truncating mutations (P < 0.001). Furthermore, all patients (16/16) with concurrent RASA1/NF1-truncating mutations lacked other known lung cancer drivers. Knockdown of RASA1 in HBECs activated signaling downstream of RAS and promoted cell growth. Conversely, restoration of RASA1 expression in RASA1-mutated cells reduced MAPK and PI3K signaling. Although growth of cell lines with inactivation of only one of these two RasGAPs showed moderate and variable sensitivity to inhibitors of MEK or PI3K, cells with concurrent RASA1/NF1 mutations were profoundly more sensitive (IC50: 0.040 μmol/L trametinib). Finally, simultaneous genetic silencing of RASA1 and NF1 sensitized both HBECs and NSCLC cells to MEK inhibition.Conclusions: Cancer genomic and functional data nominate concurrent RASA1/NF1 loss-of-function mutations as a strong mitogenic driver in NSCLC, which may sensitize to trametinib. Clin Cancer Res; 24(6); 1436-47. ©2017 AACRSee related commentary by Kitajima and Barbie, p. 1243.

Granule formation of elongator-specific methionine transfer RNA caused by X-ray irradiation in a non-small lung carcinoma cell line (NCI-H1299)

Granule formation of elongator-specific methionine transfer RNA caused by X-ray irradiation in a non-small lung carcinoma cell line (NCI-H1299)

Neuropeptide gastrin-releasing peptide induces PI3K/reactive oxygen species-dependent migration in lung adenocarcinoma cells.

Nerve fibers and neurotransmitters have increasingly been shown to have a role in tumor progression. Gastrin-releasing peptide is a neuropeptide linked to tumor aggressiveness, acting as an autocrine tumor growth factor by binding to its receptor, gastrin-releasing peptide receptor, expressed by many tumors. Although neuropeptides have been previously linked to tumor cell proliferation, more recent studies have uncovered roles for neuropeptides in chemotaxis and metastasis. Understanding the precise roles of such peptides in cancer is crucial to optimizing targeted therapy design. We have previously described that gastrin-releasing peptide acts directly as a chemotactic factor for neutrophils, dependent on PI3K, ERK, and p38. In this study, we investigated roles for gastrin-releasing peptide in lung adenocarcinoma. We asked if gastrin-releasing peptide would act as a proliferative and/or chemotactic stimulus for gastrin-releasing peptide receptor-expressing tumor cells. In A549 cells, a non-small cell lung carcinoma line, the treatment with gastrin-releasing peptide leads to activation of AKT and ERK1/2, and production of reactive oxygen species. Gastrin-releasing peptide induced migration of A549 cells, dependent on gastrin-releasing peptide receptor and PI3K, but not ERK. However, no proliferation was observed in these cells in response to gastrin-releasing peptide, and gastrin-releasing peptide did not promote resistance to treatment with a chemotherapy drug. Our results suggest that, similar to what happens in neutrophils, gastrin-releasing peptide is a migratory, rather than a proliferative, stimulus, for non-small cell lung carcinoma cells, indicating a putative role for gastrin-releasing peptide and gastrin-releasing peptide receptor in metastasis.

An HPLC method associated with a thermodynamic analysis to compare the binding of TRAIL and its nanovectorized form to death receptors DR4 and DR5 and their relationship to cytotoxicity.

TRAIL is a member of the TNF family of cytokines which induces apoptosis of cancer cells via its binding to its cognate receptors, DR5 a high affinity site and DR4 a site of low affinity. Our working group has recently demonstrated that nanovectorization of TRAIL with single wall carbon nanotubes (abbreviated NPT) enhanced TRAIL affinity to the high affinity site DR5 and increased pro apoptotic potential in different human tumor cell lines. In this paper, the DR4 low affinity site was immobilized on a chromatographic support and the effect of temperature on a wide temperature range 1°C-50°C was studied to calculate the thermodynamic parameters of the binding of TRAIL and NPT to DR4 and DR5 receptors. For the first time the heat capacity changes for the different binding processes were determined. At a physiological pH (7.4) the heat capacity changes for the binding of NPT to DR4 and DR5 were respectively equal to -0.91kJ/molK and -0.28kJ/molK and those obtained for the binding of TRAIL to DR4 and DR5 were respectively equal to -1.54kJ/molK and -1.05kJ/molK. By the use of differential scanning calorimetry (DSC), a phase transition (∼12°C for DR5, ∼4°C for DR4) between a disordered (low temperature) and an ordered (high temperature) solid like state visualized in the receptor structure confirmed the temperature dependence of binding affinity enthalpy ΔH for soluble TRAIL and its nanovectorized form to its cognate receptors. In the low temperature domain, the positive ΔH values contribute non-favourably to the free energy of binding, TRAIL and NPT described similar affinities for DR4 and DR5. For the high temperature domain, negative ΔH values indicated that van der Waals interactions and hydrogen bonding are engaged favourably at the ligand - receptor interface. Above 30°C, their rank-ordered affinities were thus strongly different in the sequence: TRAILDR4<NPTDR4<TRAILDR5< NPTDR5. The nanovectorization of TRAIL enhanced its binding to both DR4 and DR5 receptors at 37°C and could potentially sensitized cancer cells to TRAIL induced apoptosis through simultaneous activation of DR4 and DR5 as described in this paper for the non-small lung carcinoma cell line (H1703), the two hepatocarcinoma cell lines (SK-Hep1, HUH) and the colon carcinoma cell line (HCT116WT). The excellent linear coefficient (r2=1) for the plot comparing NPT cytotoxicity to TRAIL cytotoxicity confirmed a high degree of similarity for the mechanism of cytotoxicity of TRAIL and NPT between these four cell lines expressing DR4 and DR5 receptors. The slope (0.10) and the negative intercept (-1.23) of this plot indicated that NPT was much more efficient in these four cell lines as compared to TRAIL alone. As well, it was shown that the extra cellular acidosis led to the protonation of the TRAIL residue histidine by flipping the His switch to the on position with a concomitant decrease in affinity for DR4 and DR5 receptors. The highest affinity for NPT to DR4 and DR5 receptors observed at low pHs was due to the less accessibility of the His molecular switch to be protonated when TRAIL was immobilized on CNTs.

Abstract 1644: NF-κB inhibitor DMAPT blocks non-homologous end-joining repair of radiation-induced DSBs in NSCLC

Abstract Background: Despite optimal multimodality therapy, non-small cell lung carcinoma (NSCLC) remains the leading cause of cancer-related death in the United States. A common limitation is our inability to provide sufficient radiotherapy (RT) to eradicate tumor due to risk of toxicities in surrounding tissues. There is thus an unmet need for radiosensitizers that can improve the therapeutic index. Dimethylaminoparthenolide (DMAPT), an orally bioavailable small molecule NF-κB inhibitor, inhibits repair of ionizing radiation (IR)-induced DNA double strand breaks (DSBs) and increases control of subcutaneous mouse NSCLC xenografts. While our prior work focused on inhibition of homologous recombination as a mechanism for radiosensitization, we sought to characterize the effect of DMAPT on a second major DSB repair pathway, non-homologous end-joining (NHEJ). Methods: NHEJ was assessed in NSCLC lines using the pEJ reporter and flow cytometry. The NF-κB super repressor (IκBαS32A,S36A) was used as a control. Immunofluorescence and Western blotting were used to assess NHEJ biomarkers including 53BP1, DNA-PKS2056, Ku70/80 and XRCC4. Cell fractionation was performed to assess Ku chromatin binding. Quantitative RT-PCR was performed to assess gene transcription. Ku complexes were purified to identify binding partners. Results: NSCLC cells treated with IR-sensitizing doses of DMAPT (5-15 μM) or the NF-κB super repressor showed significant decreases in NHEJ. DMAPT increased the persistence of 53BP1 foci, indicating a failure to complete NHEJ. Regardless of exogenous DNA damage, there was reduced Ku70 chromatin binding following DMAPT treatment. DMAPT-treated cells produced fewer distinct IR-induced DNA-PKS2056 foci. Further, there was decreased IR-induced XRCC4 chromatin recruitment, suggesting that repair was impaired prior to ligation. There was no change in Ku70/80 transcription following DMAPT and/or IR. However, Western blotting of purified Ku complexes showed that DMAPT treatment decreased Ku association with RNA binding partners including RPL19. We also observed decreased recruitment of DNA-PKcs to the Ku complex, suggesting decreased Ku affinity for DSBs. Conclusions: These results indicate that DMAPT radiosensitizes NSCLC by perturbing the binding affinity of Ku to RNA, DNA and its complex binding partners, thus blocking NHEJ. Further mechanistic investigation and analysis of NHEJ biomarkers in vivo is needed to identify the precise mechanism. Citation Format: Peter V. Deraska, Colin O’Leary, Jean-Bernard Lazaro, Christopher J. Sweeney, Alan D. D’Andrea, David Kozono. NF-κB inhibitor DMAPT blocks non-homologous end-joining repair of radiation-induced DSBs in NSCLC. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1644.

The EGFR mutation status affects the relative biological effectiveness of carbon-ion beams in non-small cell lung carcinoma cells.

Carbon-ion radiotherapy (CIRT) holds promise to treat inoperable locally-advanced non-small cell lung carcinoma (NSCLC), a disease poorly controlled by standard chemoradiotherapy using X-rays. Since CIRT is an extremely limited medical resource, selection of NSCLC patients likely to benefit from it is important; however, biological predictors of response to CIRT are ill-defined. The present study investigated the association between the mutational status of EGFR and KRAS, driver genes frequently mutated in NSCLC, and the relative biological effectiveness (RBE) of carbon-ion beams over X-rays. The assessment of 15 NSCLC lines of different EGFR/KRAS mutational status and that of isogenic NSCLC lines expressing wild-type or mutant EGFR revealed that EGFR-mutant NSCLC cells, but not KRAS-mutant cells, show low RBE. This was attributable to (i) the high X-ray sensitivity of EGFR-mutant cells, since EGFR mutation is associated with a defect in non-homologous end joining, a major pathway for DNA double-strand break (DSB) repair, and (ii) the strong cell-killing effect of carbon-ion beams due to poor repair of carbon-ion beam-induced DSBs regardless of EGFR mutation status. These data highlight the potential of EGFR mutation status as a predictor of response to CIRT, i.e., CIRT may show a high therapeutic index in EGFR mutation-negative NSCLC.

Abstract 857: Preclinical evaluation: efficacy of DI17E6, a therapeutic antibody against alpha v integrins, compared to cilengitide in sensitizing human cancers to radiation therapy

Abstract Purpose: Integrins are implicated in resistance of solid tumors to radiation therapy, suggesting that their inhibition would enhance therapeutic efficacy. We investigated the efficacy of DI17E6, a therapeutic antibody targeting alpha v (αv) integrins, in enhancing the radiosensitivity of non-small cell lung carcinoma (NSCLC) and head &amp; neck cancer (HNSCC) cells using in vitro and in vivo models, and compared to the previously reported effects of the cyclic peptide cilengitide (inhibits αvβ3 and αvβ5 integrins). Methods: NSCLC lines (A549 and H460) and HNSCC lines (FaDu and HN-5) were examined. Basal level of αv integrin was assessed by viable cell flow-cytometry and by Western blot. The effects of DI17E6 on cell viability were determined by MTS assay, and on cellular radiosensitivity by clonogenic cell survival assay after exposing the cells to γ-radiation with or without DI17E6. In vivo effect of DI17E6 on radioresponse of xenografts was evaluated by tumor growth delay assay. DI17E6 was given i.p.; as a single loading dose of 180 mg/kg followed by weekly doses of 10, 30 or 100 mg/kg given for 6 weeks; fractionated doses of local tumor irradiation was delivered using 137Cs γ-ray source (2 Gy daily for 7 days). When combined, the loading dose of DI17E6 was given either 4 h before or after the first radiation dose. Results: DI17E6 (0.01-10 µg/ml, 24 h) had a minimal effect on the cell viability. However, DI17E6 reduced the plating efficiency of A549, H460 and FaDu with no effect on HN-5 cells. When combined with radiation, DI17E6 enhanced the radiosensitivity of NSCLC cells but not the HNSCC cells. These data are consistent with previously observed effects of cilengitide in vitro. In vivo experiments with A549 xenografts showed that DI17E6 as a single agent had no antitumor activity, but in combination with radiation it suppressed the tumor growth in a schedule- and dose-dependent manner. These data were compared to the previously reported effect of cilengitide, which did not enhance the response of A549 xenografts to radiation therapy. DI17E6 has an extended pharmacokinetics (with a half-life of &amp;gt;7 days) and blocks more αv integrins than cilengitide. The results imply that when αvβ3 and αvβ5 integrins were inhibited by cilengitide either the duration of blockade was insufficient, or that other αv integrins may have provided tumor growth advantage. In vivo studies on other tumor types are underway. Conclusions: Inhibition of αv integrins by DI17E6 in combination with radiation enhanced radiosensitivity of NSCLC cell lines in vitro and in vivo enhanced A549 tumor xenograft response to radiation in mice. These results suggest that DI17E6 may improve the treatment outcome of patients with NSCLC when combined with radiotherapy in a clinical setting. Supported by EMD Serono Merck KGaA, Germany Citation Format: Amit A. Deorukhkar, David P. Molkentine, David R. Valdecanas, Kathryn A. Mason, Uma Raju. Preclinical evaluation: efficacy of DI17E6, a therapeutic antibody against alpha v integrins, compared to cilengitide in sensitizing human cancers to radiation therapy. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 857. doi:10.1158/1538-7445.AM2014-857

Abstract A259: Characterization of next generation (Gen2.5) KRAS antisense inhibitors in NSCLC, PDAC, and CRC models.

Abstract KRAS is among the first described oncogenes and one of the most frequently mutated genes in human solid tumors. Despite substantial efforts to identify specific KRAS inhibitors, no effective therapeutic strategies to target KRAS directly have been identified. Here we describe the selective inhibition of KRAS with next generation (Gen2.5) antisense oligonucleotides. We recently demonstrated preclinical and clinical activity of a next-generation constrained-ethyl (cEt) modified (Gen 2.5) antisense oligonucleotides (ASOs) targeting STAT3 mRNA (STAT3Rx/AZD9150). Systemic delivery of unformulated STAT3Rx/AZD9150 produced robust target RNA and protein reductions in a broad range of xenograft models (AACR 2013). More importantly, STAT3Rx/AZD9150 showed striking clinical activity in the phase I dose escalation study, producing anti-tumor activity in 4 out of 6 patients with advanced treatment-refractory lymphoma (ASCO 2013). In this study, we generated a panel of high affinity Gen2.5 ASO targeting KRAS. Anti-proliferative effects of the KRAS ASOs were evaluated on a panel of colorectal carcinoma (CRC), non-small cell lung carcinoma (NSCLC) and pancreatic ductal adenocarcinoma (PDAC) cell lines. KRAS ASOs potently and selectively inhibited growth of KRAS mutant CRC lines but did not affect the growth of KRAS WT CRC cells in 2D growth assays. Evaluation of KRAS depletion in NSCLC and PDAC lines revealed that sensitivity of these lines to growth inhibition in 2D assays required mutant KRAS status and the presence of a previously described “KRAS addiction” gene expression signature (Singh et al 2009). Surprisingly, further evaluation of KRAS ASO mediated depletion of NSCLC and PDAC lines in 3D growth assays (e.g. soft agar colony formation and polystyrene sponge (Alvetex)) resulted in strong inhibition of colony formation in all mutant KRAS lines, but not WT KRAS lines, and the sensitivity to KRAS depletion was independent of the expression of the “KRAS addiction” signature. Collectively, we have shown that KRAS mutational status confers specific sensitivity to the ASO-mediated KRAS knockdown (KRAS oncogene addiction). Our data also highlights that antisense-mediated inhibition of KRAS may represent a promising and translatable approach to target KRAS therapeutically. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A259. Citation Format: Alexey S. Revenko, Gourab Bhattachrjee, Chris May, Brett P. Monia, A. Robert MacLeod. Characterization of next generation (Gen2.5) KRAS antisense inhibitors in NSCLC, PDAC, and CRC models. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A259.

Odin (ANKS1A) Modulates EGF Receptor Recycling and Stability

The ANKS1A gene product, also known as Odin, was first identified as a tyrosine-phosphorylated component of the epidermal growth factor receptor network. Here we show that Odin functions as an effector of EGFR recycling. In EGF-stimulated HEK293 cells tyrosine phosphorylation of Odin was induced prior to EGFR internalization and independent of EGFR-to-ERK signaling. Over-expression of Odin increased EGF-induced EGFR trafficking to recycling endosomes and recycling back to the cell surface, and decreased trafficking to lysosomes and degradation. Conversely, Odin knockdown in both HEK293 and the non-small cell lung carcinoma line RVH6849, which expresses roughly 10-fold more EGF receptors than HEK293, caused decreased EGFR recycling and accelerated trafficking to the lysosome and degradation. By governing the endocytic fate of internalized receptors, Odin may provide a layer of regulation that enables cells to contend with receptor cell densities and ligand concentration gradients that are physiologically and pathologically highly variable.

Genetic and molecular biomarker characterization of KRAS mutant non-small cell lung carcinoma (NSCLC) tumors.

11026 Background: Preclinical studies demonstrated Brahma related gene 1 (BRG1) mutations or loss of expression, and mutations of LKB1 may be associated with lack of sensitivity for MEK inhibitor trametinib in a subset of KRAS mutant NSCLC lines. This study aimed to evaluate the frequency of KRAS, LKB1 and BRG1 mutations in NSCLC tumors; and determine whether KRAS mutations in corresponding plasma samples could be detected by evaluating circulating cell-free DNA (cfDNA). Methods: Human NSCLC FFPE tumor tissue and matched plasma samples were procured from Indivumed GmbH. KRAS mutation status of 101 NSCLC tumors and matched plasma were determined by direct sequencing of genomic DNA (gDNA) from tissue and/or BEAMing on tissue gDNA or plasma cfDNA. Genetic mutations of LKB1 and BRG1 were determined by direct sequencing. Additional mutations were determined using the Ion Torrent AmpliSeq Cancer Panel. BRG1 protein expression was evaluated by IHC. Results: By direct sequencing and BEAMing we found 27/101 (28.4%) NSCLC tissue and/or plasma samples harbored KRAS mutations: G12V (37.0%), G12C (29.6%), G12D (18.5%), G12S, G13C, G13D and Q61H (3.7% each). The KRAS mutation status concordance (mutant or wild-type) between tumor gDNA and plasma cfDNA was 79-81%. Among the KRAS mutant tumors, LKB1 and BRG1 mutations were detected in 10/26 (38%) and 1/26 (3.8%) tumors respectively by direct sequencing. By IHC, loss of BRG1 expression was detected in 1/21 KRAS mutant tumors. The mutation frequency and variants for KRAS and LKB1 in patient samples were comparable with KRAS mutant NSCLC cell lines and COSMIC database. However the frequency of BRG1 mutation and protein loss were much lower in patient tumors. In a subset of 15 KRAS mutant tumors, Ion Torrent confirmed KRAS and LKB1 mutations and provided additional mutations found in TP53, FGFR2, FGFR3, GNAS, KDR, KIT and MET. Conclusions: This study demonstrates that KRAS mutant NSCLC tissues have high frequency of LKB1 mutations along with other mutations. It also supports the feasibility of detection of KRAS mutations in cfDNA from blood of NSCLC patients using BEAMing technology, providing an alternative to invasive biopsy.

Abstract 168: Cytokine signaling through the JAK2/STAT3 pathway is a viable therapeutic target in non-small cell lung cancer

Abstract The emergence of molecular methods for classifying solid tumors based upon specific “driver mutations” has made rationally-designed chemotherapy possible in a variety of cancers. Non-small cell lung carcinoma (NSCLC) is a prototypical example of these clinical advances, and is routinely treated with targeted kinase inhibitors including erlotinib and gefitinib. Despite the success of this approach, drug resistance continues to be a significant problem in patients with advanced NSCLC. Constitutive activation of STAT3 is a common feature in non-small cell lung carcinoma (NSCLC), and has been proposed to play an important role in tumor cell resistance to conventional and targeted small-molecule therapies. Previous studies have suggested that STAT3 can be activated in NSCLC by hyperactive growth factor receptors or cytokine signaling, though the interplay between STAT3 activation and other well-characterized oncogenic “driver” mutations in NSCLC has not been fully characterized. We analyzed the activation status of key growth factor signaling pathways in seven NSCLC lines with four distinct classes of driver mutations, including activating mutations to KRAS and several receptor tyrosine kinases (EGFR, MET, PDGFRA). Targeted pharmacologic inhibitors were used to evaluate the relative contribution of each oncogene to signaling pathway activation. While common downstream effectors such as ERK, AKT, mTOR were repressed by these drugs, we observed that STAT3 remained activated in all seven cell lines independent of mutational subtype. However, pharmacologic or genetic inhibition of the gp130/Janus kinase (JAK2) signaling pathway uniformly disrupted STAT3 activation. Interestingly, only 3/7 lines produced significant levels of the cytokine interleukin-6 (IL-6), which was previously suggested to be the key mediator of gp130/JAK2 signaling in NSCLC. Gene expression and ELISA analysis of other IL-6 family ligands suggests that cardiotrophin-like cytokine factor-1 (CLCF1) may be responsible for pathway activation in the other four cell lines lacking IL-6. At the functional level, treatment of cells with the JAK1/2 inhibitor ruxolitinib had little effect on proliferation and viability in two-dimensional culture, though it inhibited anchorage-independent growth of NSCLC cells in soft agar. Ruxolitinib also slowed growth of xenografted NSCLC cells, indicating that JAK2 activity is required for optimal growth of lung tumors in vivo. Together these results demonstrate that JAK2/STAT3 signaling operates independent of known driver mutations in NSCLC and may play a key role in growth and/or progression of lung tumors. We suggest that addition of a JAK2 inhibitor to therapies which target commonly altered oncogenes such as KRAS or EGFR will improve clinical outcomes for NSCLC patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 168. doi:1538-7445.AM2012-168