Non-small Cell Lung Carcinoma Xenografts Research Articles

Detection of MiRNA-126-5p in Non-Small Cell Lung Cancer Cells by Nano-Polymerase Chain Reaction and Its Regulatory Mechanism of Radiation Sensitivity to Cancer Cells

Radiotherapy resistance remains a huge hindrance in treating non-small cell lung carcinoma (NSCLC). Hyperthermia, a treatment method that raises the cell temperature to treat tumors, has been putting in clinical application combined with conventional chemotherapy and radiotherapy to enhance their effectiveness in NSCLC treatment. However, the specific mechanism of this combination therapy has not been extensively researched. In this study, we established a radiation-resistant NSCLC cell line by sequential radiation exposure. It was shown that the combination of hyperthermia and radiotherapy suppressed NSCLC xenograft tumor growth and increased radiation-induced apoptosis. Furthermore, downregulation of miR-126-5p was found in radio-resistant NSCLC cells. The results of bioinformatics analysis based on ENCORI showed that RAD50 is a direct target of miR-126-5p. Overexpressed miR-126-5p increased radiation-induced cell death by suppressing RAD50 expression. Hyperthermia treatment increases miR-126-5p and decreases RAD50, leading to more unrepaired DNA damage and greater cellular death. In conclusion, hyperthermia enhances NSCLC cells’ radio-sensitivity via miR-126-5p/RAD50 axis.

Abstract 6246: The MTA-cooperative PRMT5 inhibitor AM-9747 exhibits robust antitumor activity in combination with clinically relevant chemotherapies and targeted agents in MTAP null tumor models

Abstract Homozygous deletion of chr9p21, containing genes CDKN2A and MTAP, occurs in about 15% of cancers. MTAP loss, a key enzyme in the methionine and adenine salvage pathways, leads to the accumulation of its substrate MTA. MTA competes with the methyl donor SAM for binding to type II arginine methyltransferase PRMT5, placing PRMT5 in a hypomorphic state and vulnerable to further PRMT5 inhibition. MTA-cooperative PRMT5 inhibitors are an emerging class of therapeutics targeting MTAP null tumors. AMG 193, currently in Phase 1 trials, and its representative analog AM-9747 have broad spectrum activity in MTAP null tumor models across hematologic and solid tumor indications. Mechanistically, AM-9747 induces DNA damage, shown by increased phosphorylated H2AX, resulting in cell cycle arrest and senescence. Exploration of clinically relevant therapeutic combinations with standard of care (SOC) chemotherapies or targeted agents that could potentiate this DNA damage or target orthogonal pathways is a rational therapeutic approach. Here, we evaluated AM-9747 in combination with SOC chemotherapies and assessed synergy using the Chou-Talalay Method to generate Combination Index (CI) scores. SOC agents representing a variety of mechanisms of action (paclitaxel, carboplatin, gemcitabine, pemetrexed, irinotecan, 5-FU) were evaluated and results ranged from strongly synergistic (CI<0.3) to additive (CI=1) in a panel of non-small cell lung carcinoma (NSCLC) and pancreatic cancer cell lines. The SOC combinations augmented AM-9747 induced DNA damage resulting in increased cell cycle arrest and nuclear count assays confirmed the synergistic antiproliferative effects of the combinations. Combinations of AM-9747 and one strongly synergistic agent (carboplatin) and one moderately synergistic agent (paclitaxel) were evaluated in H292 NSCLC xenografts. Significant reductions in tumor burden compared to single agent treatments were observed with AM-9747 + paclitaxel (67% TGI) and AM-9747 + carboplatin (82% TGI). Additionally, roughly 2-3% of NSCLC tumors harbor both MTAP loss and a KRAS G12C mutation. To target both pathways we combined the FDA-approved KRAS G12C inhibitor sotorasib with AM-9747 and observed synergy (CI<0.6) in MIAPACA2 cells. Nuclear counts confirmed a greater cell growth inhibition in the combination and immunoblots confirmed on target inhibition of both pathways. Combination treatment of AM-9747 and sotorasib in LU99 NSCLC xenografts resulted in significant tumor regression compared to each single agent with 10/10 mice tumor free. This combination is being tested in additional MTAP null KRAS G12C mutant models. Overall, our data suggests that combining MTA-cooperative inhibitor AM-9747 with SOC or clinically relevant targeted agents is a compelling therapeutic strategy for the treatment of MTAP null cancers. Citation Format: Katherine Slemmons, Brian Belmontes, Siyuan Liu, Jodi Moriguchi, Antonia Policheni, Paul E. Hughes. The MTA-cooperative PRMT5 inhibitor AM-9747 exhibits robust antitumor activity in combination with clinically relevant chemotherapies and targeted agents in MTAP null tumor models. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6246.

Chemokine Receptors CCR6 and PD1 Blocking scFv E27 Enhances Anti-EGFR CAR-T Therapeutic Efficacy in a Preclinical Model of Human Non-Small Cell Lung Carcinoma.

Chimeric antigen receptor (CAR)-T cells, a therapeutic agent for solid tumors, are not completely effective due to a lack of infiltration of T cells into the tumor site and immunity caused by Programmed Death Receptor 1(PD1). Here, an epidermal growth factor receptor (EGFR) CAR-T cell was engineered to express the chemokine receptor CCR6 and secrete PD1 blocking Single-chain antibody fragment (scFv) E27 to enhance their anti-tumor effects. The findings showed that CCR6 enhanced the migration of EGFR CAR-E27-CCR6 T cells in vitro by the Transwell migration assay. When incubated with tumor cells, EGFR CAR-E27-CCR6 T cells specifically exerted potent cytotoxicity and produced high levels of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-2 (IL-2), and interferon-γ (IFN-γ). A non-small cell lung carcinoma (NSCLC) cell line-derived xenograft model was constructed by implanting modified A549 cell lines into immunodeficient NOD.PrkdcscidIl2rgem1/Smoc (NSG) mice. In comparison with traditional EGFR CAR-T cells, live imaging indicated that EGFR CAR-E27-CCR6 T cells displayed superior anti-tumor function. In addition, the histopathological examination of mouse organs showed no obvious organic damage. Our findings confirmed that PD1 blocking and CCR6 can enhance the anti-tumor function of EGFR CAR-T cells in an NSCLC xenograft model, providing an effective treatment strategy to improve the efficacy of CAR-T in NSCLC.

Cationic amphiphilic antihistamines inhibit STAT3 via Ca2+-dependent lysosomal H+ efflux.

Commonly used antihistamines and other cationic amphiphilic drugs (CADs) are emerging as putative cancer drugs. Their unique chemical structure enables CADs to accumulate rapidly inside lysosomes, where they increase lysosomal pH, alter lysosomal lipid metabolism, and eventually cause lysosomal membrane permeabilization. Here, we show that CAD-induced rapid elevation in lysosomal pH is caused by a lysosomal H+ efflux that requires P2RX4-mediated lysosomal Ca2+ release and precedes the lysosomal membrane permeabilization. The subsequent cytosolic acidification triggers the dephosphorylation, lysosomal translocation, and inactivation of the oncogenic signal transducer and activator of transcription 3 (STAT3) transcription factor. Moreover, CAD-induced lysosomal H+ efflux sensitizes cancer cells to apoptosis induced by STAT3 inhibition and acts synergistically with STAT3 inhibition in restricting the tumor growth of A549 non-small cell lung carcinoma xenografts. These findings identify lysosomal H+ efflux and STAT3 inhibition as anticancer mechanisms of CADs and reinforce the repurposing of safe and inexpensive CADs as cancer drugs with a drug combination strategy.

Nano-Targeting of Thyrointegrin αvβ3 Receptor in Solid Tumors and Impact on Radiosensitization.

Tetraiodothyroacetic acid is a ligand of thyrointegrin αvβ3, a protein that is highly expressed in various solid tumors and surrounding neovascular regions. Its nano derivative, Nano-diamino-tetrac (NDAT), has anticancer properties in preclinical models, enhances radiosensitivity, and inhibits cancer cell growth in vitro after X-ray irradiation. Using a novel experimental system developed to deliver accurate radiation dose to tumors under sterile conditions, this study establishes NDAT's radiosensitizing effect in SUIT-2 pancreatic cancer and H1299 non-small cell lung carcinoma xenografts in athymic mice for tumor-targeted radiation. In this work, low-melting-point Lipowitz alloy was used to shield normal organs and allow accurate tumor-targeted irradiation. Over a three-week period, mice with SUIT-2 xenografts received daily NDAT treatment at different doses (0, 1, 3, or 10 mg/kg body weight) and tumor-targeted irradiation (1 or 5 Gy). Validation was performed with a test dose of 30 Gy to mice bearing SUIT-2 xenografts and resulted in more than 80% reduction in tumor weight, compared to nonirradiated tumor weight. The results of this work showed that NDAT had a radiosensitizing effect in a dose-dependent manner in decreasing tumor growth and viability. An enhanced anticancer effect of NDAT (1 mg/kg body weight) was observed in mice with H1299 xenografts receiving 5 Gy tumor-targeted irradiation, indicated by decreased tumor weight and increased necrosis, compared to nonirradiated tumors. This technique demonstrated accurate tumor-targeted irradiation with new shielding methodology, and combined with thyrointegrin antagonist NDAT treatment, showed anticancer efficacy in pancreatic cancer and non-small cell lung carcinoma.

The Anti-Non-Small Cell Lung Cancer Cell Activity by a mTOR Kinase Inhibitor PQR620.

In non-small-cell lung carcinoma (NSCLC), aberrant activation of mammalian target of rapamycin (mTOR) contributes to tumorigenesis and cancer progression. PQR620 is a novel and highly-potent mTOR kinase inhibitor. We here tested its potential activity in NSCLC cells. In primary human NSCLC cells and established cell lines (A549 and NCI-H1944), PQR620 inhibited cell growth, proliferation, and cell cycle progression, as well as cell migration and invasion, while inducing significant apoptosis activation. PQR620 disrupted assembles of mTOR complex 1 (mTOR-Raptor) and mTOR complex 2 (mTOR-Rictor-Sin1), and blocked Akt, S6K1, and S6 phosphorylations in NSCLC cells. Restoring Akt-mTOR activation by a constitutively-active Akt1 (S473D) only partially inhibited PQR620-induced cytotoxicity in NSCLC cells. PQR620 was yet cytotoxic in Akt1/2-silenced NSCLC cells, supporting the existence of Akt-mTOR-independent mechanisms. Indeed, PQR620 induced sphingosine kinase 1 (SphK1) inhibition, ceramide production and oxidative stress in primary NSCLC cells. In vivo studies demonstrated that daily oral administration of a single dose of PQR620 potently inhibited primary NSCLC xenograft growth in severe combined immune deficient mice. In PQR620-treated xenograft tissues, Akt-mTOR inactivation, apoptosis induction, SphK1 inhibition and oxidative stress were detected. In conclusion, PQR620 exerted potent anti-NSCLC cell activity via mTOR-dependent and -independent mechanisms.

Calcium channel \u03b12\u03b41 subunit is a functional marker and therapeutic target for tumor-initiating cells in non-small cell lung cancer

It is hypothesized that tumor-initiating cells (TICs) with stem cell-like properties constitute a sustaining force to drive tumor growth and renew fully established malignancy. However, the identification of such a population in non-small cell lung carcinoma (NSCLC) has been hindered by the lacking of reliable surface markers, and very few of the currently available surface markers are of functional significance. Here, we demonstrate that a subpopulation of TICs could be specifically defined by the voltage-gated calcium channel α2δ1 subunit from non-small cell lung carcinoma (NSCLC) cell lines and clinical specimens. The α2δ1+ NSCLC TICs are refractory to conventional chemotherapy, and own stem cell-like properties such as self-renewal, and the ability to generate heterogeneous tumors in NOD/SCID mice. Moreover, α2δ1+ NSCLC cells are more enriched for TICs than CD133+, or CD166+ cells. Interestingly, α2δ1 is functionally sufficient and indispensable to promote TIC properties by mediating Ca2+ influx into cells, which subsequently activate Calcineurin/NFATc2 signaling that directly activates the expression of NOTCH3, ABCG2. Importantly, a specific antibody against α2δ1 has remarkably therapeutic effects on NSCLC xenografts by eradicating TICs. Hence, targeting α2δ1 to prevent calcium influx provides a novel strategy for targeted therapy against TICs of NSCLC.

Abstract 1485: E7011, a novel anti-angiogenesis inhibitor targeting Notch4 receptor signal pathway

Abstract Notch4 is selectively expressed on tumor endothelial cells and hypothesized to contribute to cancer malignancy through mechanisms including tumor angiogenesis regulation and promoting drug resistance. We developed E7011, a humanized IgG2κ antibody targeting Notch4 receptor signaling. To obtain anti-human Notch4 monoclonal antibody, human Notch4 3EGFR (epidermal growth factor repeat) domain - NRR (negative regulatory region) - SEAP (secreted alkaline phosphatase) - His protein was immunized to mice and 6698 hybridomas were obtained. By screening these clones with the Notch4 binding assay and Notch4-specific gal4-fusion luciferase reporter assay, mouse anti-human Notch4 mAb clone (6-3-A6) was selected. The CDRs (complementarity determining regions) of 6-3-A6 were grafted into the variable regions of human IgG2κ, and E7011, novel humanized anti-human Notch4 monoclonal antibody, was developed by screening in assays above. The biomolecular interaction analysis showed that E7011 is able to bind to human and mouse Notch4-NRR domain-SEAP-His, and inhibit human Notch4 receptor signaling in an antibody-dose dependent manner as well as 6-3-A6. IHC analysis showed that Notch4 was expressed on CD31 positive endothelial cells in Calu6 human non-small cell lung carcinoma xenograft tumor. Intravenous administration of E7011 at 1, 3, 10 mg/kg in twice a week significantly decreased tumor growth compared with control IgG treatment without severe body weight loss. We also investigated the functional tumor angiogenesis by hoechest dye-perfusion and staining with anti-CD31 antibody in the Calu6 xenograft model. E7011 treatment significantly decreased hoechst-positive perfusion area compared with vehicle treatment. In conclusion, E7011 is a novel antitumor agent that is a specific signal inhibitor targeting the Notch4 receptor and suppresses tumor growth through decreasing tumor vessel function in based on preclinical studies. Citation Format: Yusuke Adachi, Yoshimasa Sakamoto, Youya Nakazawa, Sho Tachino, Ken Ito, Takanori Abe, Yukinori Minoshima, Kana Hoshino-Negishi, Hideaki Ogasawara, Tomomi Kawakatsu, Miyuki Nishimura, Masashi Shimizu, Kazuhiro Tahara, Toshitaka Sato, Katsuhisa Suzuki, Kishan Agarwala, Masao Iwata, Yasuhiro Funahashi, Kenichi Nomoto, Yoichi Ozawa, Junji Matsui, Toshio Imai, Yu Kato. E7011, a novel anti-angiogenesis inhibitor targeting Notch4 receptor signal pathway [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 1485.

Targeting PD-L1 in non-small cell lung cancer using CAR T cells

Antibodies against programmed cell death protein 1 (PD-1) and its ligand (PD-L1) have dramatically changed the landscape of therapies for non-small cell lung carcinoma (NSCLC); however, the majority of patients do not respond to these agents. In addition, hyperprogressive disease (HPD) develops in a larger portion of NSCLC patients treated with PD-1/PD-L1 inhibitors than in patients treated with standard chemotherapy. The use of chimeric antigen receptor (CAR) T cells has been successful to treat blood cancers but not for solid tumors like NSCLC. In this work, we constructed CAR T cells that target PD-L1 and evaluated their efficacy in NSCLC with either high or low PD-L1 expression. PD-L1-CAR T cells exhibited antigen-specific activation, cytokine production, and cytotoxic activity against PD-L1high NSCLC cells and xenograft tumors. Furthermore, the addition of a subtherapeutic dose of local radiotherapy improved the efficacy of PD-L1-CAR T cells against PD-L1low NSCLC cells and tumors. Our findings indicate that PD-L1-CAR T cells represent a novel therapeutic strategy for patients with PD-L1-positive NSCLC, particularly for those who are susceptible to HPD.

Ginsenosides synergize with mitomycin C in combating human non-small cell lung cancer by repressing Rad51-mediated DNA repair.

The use of ginseng extract as an adjuvant for cancer treatment has been reported in both animal models and clinical applications, but its molecular mechanisms have not been fully elucidated. Mitomycin C (MMC), an anticancer antibiotic used as a first- or second-line regimen in the treatment for non-small cell lung carcinoma (NSCLC), causes serious adverse reactions when used alone. Here, by using both in vitro and in vivo experiments, we provide evidence for an optimal therapy for NSCLC with total ginsenosides extract (TGS), which significantly enhanced the MMC-induced cytotoxicity against NSCLC A549 and PC-9 cells in vitro when used in combination with relatively low concentrations of MMC. A NSCLC xenograft mouse model was used to confirm the in vivo synergistic effects of the combination of TGS with MMC. Further investigation revealed that TGS could significantly reverse MMC-induced S-phase cell cycle arrest and inhibit Rad51-mediated DNA damage repair, which was evidenced by the inhibitory effects of TGS on the levels of phospho-MEK1/2, phospho-ERK1/2 and Rad51 protein and the translocation of Rad51 from the cytoplasm to the nucleus in response to MMC. In summary, our results demonstrate that TGS could effectively enhance the cytotoxicity of MMC against NSCLC cells in vitro and in vivo, thereby revealing a novel adjuvant anticancer mechanism of TGS. Combined treatment with TGS and MMC can significantly lower the required concentration of MMC and can further reduce the risk of side effects, suggesting a better treatment option for NSCLC patients.

Abstract LB-319: Development and characterization of ADC999: A novel, potent orally available Wee1 inhibitor with robust antitumor efficacy in vivo

Abstract Wee1 is a tyrosine kinase that phosphorylates cyclin-dependent kinase 1 (CDC2) to inactivate the CDC2/cyclinB complex. Wee1 is therefore a key regulator of the cell cycle, maintaining the G2 checkpoint arrest to allow for pre-mitotic repair upon genomic stress. Unlike normal cells, most p53-deficient tumors lack a functional G1 checkpoint and instead rely on the G2 checkpoint for DNA repair. Abrogation of the G2 checkpoint by a Wee1 inhibitor has been shown to sensitize p53-deficient tumors to a variety of DNA-damaging anticancer agents. Strong chemosensitization has also been demonstrated in multiple pre-clinical models using targeted agents including CHK1 or PARP inhibitors. These studies combined with recent clinical data demonstrating robust anti-tumor activity in combination with carboplatin or as a single agent in tumors under high replicative stress make Wee1 a promising target for anticancer therapy. With only one inhibitor (AZD1775) in clinical development and very few reports of compounds at the preclinical stage, the development of alternative Wee1 inhibitors is of significant medical relevance. In this study, we describe the development of a novel and highly potent small molecule inhibitor of Wee1 (ADC999) and subsequent analogs. These inhibitors exhibit single digit nM IC50 values against Wee1 and good overall selectivity profiles against the kinome. In cells, target engagement was demonstrated through the inhibition of both CDC2- and CDK2-dependent Wee1 phosphorylation. In line with the mechanism of action, γH2AX and apoptosis induction was also observed in a dose-dependent manner. Further profiling in a panel of cell lines indicated strong anti-proliferative activity both in combination with cytotoxics and in monotherapy. Single agent activity was observed in multiple cancer types, including gynecological, lung and breast. In vivo, oral administration of ADC999 as a single agent led to excellent antitumor activity in a KRAS-mutant non-small cell lung carcinoma xenograft model. Responses ranged from dose-dependent tumor growth inhibition to complete and sustained regressions. ADC999 was well tolerated following a daily dosing regimen and over a prolonged period with no adverse effects observed. Evaluation of ADC999 anti-tumor activity will also be discussed in a panel of genetically-characterized patient-derived xenografts (PDXs) both as monotherapy (mini-trial design) and in combination with PARP inhibitors. In summary, we describe the development and profiling of a novel, highly potent orally available Wee1 inhibitor with robust antitumor efficacy in vivo. This inhibitor and potential back-up compounds will provide new opportunities to fully exploit the therapeutic potential of Wee1 inhibition both as standalone intervention and in combination modalities. Citation Format: Gerald Gavory, Colin O'Dowd, Ewelina Rozycka, Caroline Boyd, Beronia Gorges, Estelle McLean, Julien Daubriac, Shane Rountree, Steven Shepherd, Stephanie Burton, Mary McFarland, Adam Treder, Andy Wilkinson, Frank Burkamp, Tim Harrison. Development and characterization of ADC999: A novel, potent orally available Wee1 inhibitor with robust antitumor efficacy in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-319. doi:10.1158/1538-7445.AM2017-LB-319

Abstract 3325: Ginkgetin, a biflavonoid derived from leaves of Ginkgo biloba, induces autophagic cell death in non-small cell lung cancer via p62

Abstract Chemotherapeutic drugs in the treatment of non-small-cell lung carcinoma (NSCLC) are usually mediated by induction of apoptosis; this usually results in drug resistant during the therapy. Many compounds from natural resource have been shown to trigger autophagy in promoting cell death, and therefore which could be a novel treatment for cancer. Ginkgetin, a biflavonoid from Ginkgo biloba leaves (Ginkgoaceae), was shown its anticancer effects recently. The leaf of G. biloba is being recorded as a safe herbal drug in Pharmacopoeia from China and Europe. Here, the possible development of ginkgetin as an anticancer drug was demonstrated. Ginkgetin induced the death in A549 (NSCLC) with an IC50 lower than that of cisplatin. This anticancer effect of ginkgetin was also illustrated in NSCLC xenograft nude mice model. Transmission electronic microscope revealed that ginkgetin-induced autophagy was the main cause of cell death. Autophagy inhibitors, 3-methyladenine and chloroquine but not apoptosis inhibitor Z-VAD-FMK, rescued ginkgetin-induced cell death. Reciprocally, the induction of autophagy by rapamycin promoted ginkgetin-induced cell death, as well as the formation of p62-TRAF6-mTOR. During autophagy, p62 is hypothesized to be a target of ginkgetin-induced autophagic cell death. This notion is supported by several lines of evidence. The application of ginkgetin blocked fully the expression of p62 in cultured A549, and in contrast the over expression of p62 reduced ginkgetin-induced autophagy and cell death concomitantly with the decline on autophagosome formation. In parallel, the modulation on p62 expression could regulate Nrf2 activity and ROS level in the presence of ginkgetin. Thus, autophagy could act as an inducer in ginkgetin-induced cell death, and p62 was proposed to be a possible target during this process. Here, ginkgetin exhibited promising anticancer effect in NSCLC via autophagy, a signaling very different to orthodox chemotherapeutic drug cisplatin. Besides, ginkgetin is a phytochemical from G. biloba that is considered as a safe herbal supplement, and no obvious toxicity was observed in xenograft nude mice. Therefore, ginkgetin is proposed to be a potential compound for the development of novel anticancer drug. Acknowledgements: This study was supported by Hong Kong Research Grants Council Theme-based Research Scheme (T13-607/12R), GRF (663012, 662713, M-HKUST604/13), TUYF15SC01 and Foundation of The Awareness of Nature (TAON12SC01) to Karl Tsim. Citation Format: Jian Shu Lou, Cathy Bi, Gallant Chan, Tina Dong, Karl Tsim. Ginkgetin, a biflavonoid derived from leaves of Ginkgo biloba, induces autophagic cell death in non-small cell lung cancer via p62 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3325. doi:10.1158/1538-7445.AM2017-3325

TRIM14 is a Putative Tumor Suppressor and Regulator of Innate Immune Response in Non-Small Cell Lung Cancer

Non-small-cell lung carcinoma (NSCLC) accounts for 85% of malignant lung tumors and is the leading cause of cancer deaths. Our group previously identified Tripartite Motif 14 (TRIM14) as a component of a prognostic multigene expression signature for NSCLC. Little is known about the function of TRIM14 protein in normal or disease states. We investigated the functional and prognostic role of TRIM14 in NSCLC using in vitro and in vivo perturbation model systems. Firstly, a pooled RNAi screen identified TRIM14 to effect cell proliferation/survival in NSCLC cells. Secondly, silencing of TRIM14 expression significantly enhanced tumor growth in NSCLC xenograft mouse models, while exogenous TRIM14 expression attenuated tumorigenesis. In addition, differences in apoptotic activity between TRIM14-deficient and control tumors suggests that TRIM14 tumor suppressor activity may depend on cell death signaling pathways. TRIM14-deficient cell lines showed both resistance to hypoxia-induced cell death and attenuation of interferon response via STAT1 signaling. Consistent with these phenotypes, multivariate analyses on published mRNA expression datasets of over 600 primary NSCLCs demonstrated that low TRIM14 mRNA levels are significantly associated with poorer prognosis in early stage NSCLC patients. Our functional data therefore establish a novel tumor suppressive role for TRIM14 in NSCLC progression.

Puerarin inhibits M2 polarization and metastasis of tumor-associated macrophages from NSCLC xenograft model via inactivating MEK/ERK 1/2 pathway.

Non-small cell lung carcinoma (NSCLC) metastasis is responsible for most of cancer-related mortality. The tumor associated macrophages (TAMs) are known to be crucial cells in lung cancer and are usually divided into two antagonistic types, M1 and M2. Puerarin has a wide spectrum of pharmacological properties. The present study explores puerarin on macrophage polarization and metastasis of NSCLC. The results demonstrated that puerarin inhibited tumor growth and tumor volumes in NSCLC xenograft model, increased M1 markers [CD197+, inducible nitric oxide synthase (iNOS)+, CD40+)] and reduced M2 markers (CD206+, Arg-1+ and CD163+). Besides, puerarin elevated the level of pro-inflammatory cytokine interferon (IFN)-γ, tumor necrosis factor (TNF)-α and interleukin (IL)-12, decreased the expression of pro-tumor cytokines IL-10, IL-4 and transforming growth factor (TGF)-β. To explore whether puerarin directly acts on macrophages, we purified macrophages from NSCLC model, the results showed that puerarin inhibited macrophages polarized to M2 phenotype and did not require the auxiliary of other cells. In addition, puerarin suppressed the invasion and migration of NSCLC macrophages, restrained the expression of angiogenesis factors. Puerarin also inhibited the activation of mitogen-activated extracellular signal-regulated kinase (MEK)/extracellular signal-regulated kinase (ERK) 1/2 pathway through inhibition of ERK nucleus translocation. Finally, IL-4 induced M2 macrophage polarization and metastasis were partially offset by puerarin through inactivating the MEK/ERK 1/2 pathway. Taken together, this study validated that puerarin is able to skew macrophage populations back to M1 subsets to stimulate antitumor effects and suggests puerarin is a negative metastatic regulator of NSCLC.

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.

Abstract 5516: Biodistribution of liposomal docetaxel prodrug MNK-010 in mice bearing A549 human NSCLC xenografts

Abstract The anti-mitotic taxanes belong to one of the most important families of anticancer drugs that have broad anti-tumor activity and are widely used for a variety of human cancer types. However, the taxanes are limited by a number of serious pharmacological and toxicological effects. We are developing a unique delivery system for docetaxel, comprised of a PEGylated liposomal nanoparticle containing a prodrug of docetaxel to improve solubility, tolerability and increase efficacy through improved pharmacokinetics and biodistribution. In this study we evaluated the biodistribution of MNK-010, a liposomal formulation of a docetaxel prodrug in immunodeficient mice bearing A549 Human Non-Small Cell Lung Carcinoma (NSCLC) xenografts. This study tested the hypothesis that MNK-010 can produce greater plasma and tumor accumulation of docetaxel than with delivery of standard of care free docetaxel in tumor-bearing mice. Female nude mice bearing A549 human NSCLC xenografts were given a single intravenous (IV) dose of MNK-010 (40 mg/kg docetaxel molar equivalent) or free docetaxel (50 mg/kg). For each treatment group, three animals were sacrificed at various time points between 1 hr and 504 hr post injection. After euthanasia, blood, tumor, liver, kidney, spleen, lung and skeletal muscle specimens were collected. Tissue and blood samples were assayed to determine docetaxel concentrations. Administration of MNK-010 IV provided a reservoir for the continual slow release of docetaxel in the circulation and in tumors. MNK-010 increased systemic docetaxel exposure (AUC) ten-fold greater than free docetaxel injected at similar doses. MNK-010 produced sustained docetaxel levels in tumor through the 21 day observation period, resulting in four-fold greater docetaxel tumor exposure (AUC) compared to free docetaxel. The increase in MNK-010 plasma exposure as well as the enhanced permeability effect observed with liposomes likely contributed to the increased tumor exposure. In addition to improved accumulating in tumor tissue, docetaxel derived from MNK-010 also accumulated in liver, spleen and kidney. These tissues contain phagocytic cells (macrophages or mesangial) and serve as organs of elimination for chemotherapeutics. Docetaxel derived from MNK-010 was not detectable in skeletal muscle and was only found in lung over the first 24 hours post administration. In contrast, IV injection of free docetaxel produced high initial concentrations of docetaxel in all tissues evaluated, before falling quickly over time. Tumor levels decreased below levels of quantitation after nine days. This study demonstrated that Mallinckrodt Pharmaceuticals’ PEGylated liposomal docetaxel prodrug MNK-010 provided a reservoir for the continual release of docetaxel into the systemic circulation and produced an enhanced accumulation of docetaxel in A549 human NSCLC xenografts in mice compared to the standard of care docetaxel. Citation Format: Richard M. Fitch, James H. Wible, James A. Blackledge, William D. McGhee. Biodistribution of liposomal docetaxel prodrug MNK-010 in mice bearing A549 human NSCLC xenografts. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5516. doi:10.1158/1538-7445.AM2015-5516

Antitumor activity of selective MEK1/2 inhibitor AZD6244 in combination with PI3K/mTOR inhibitor BEZ235 in gefitinib-resistant NSCLC xenograft models

PurposeAlthough the EGF receptor tyrosine kinase inhibitors (EGFR-TKI) gefitinib have shown dramatic effects against EGFR mutant lung cancer, patients become resistant by various mechanisms, including gatekeeper EGFR-T790M mutation, MET amplification, and KRAS mutation, thereafter relapsing. AZD6244 is a potent, selective, and orally available MEK1/2 inhibitor. In this study, we evaluated the therapeutic efficacy of AZD6244 alone or with BEZ235, an orally available potent inhibitor of phosphatidylinositol 3–kinase (PI3K) and mammalian target of rapamycin (mTOR), in gefitinib-resistant non-small cell lung carcinoma (NSCLC) models.Experimental designNCI-H1975 with EGFR-T790M mutation, NCI-H1993 with MET amplification and NCI-H460 with KRAS/PIK3CA mutation human NSCLC cells were subcutaneous injected into the athymic nude mice respectively. Mice were randomly assigned to treatment with AZD6244, BEZ235, AZD6244 plus BEZ235, or control for 3 weeks, then all mice were sacrificed and tumor tissues were subjected to western blot analyses and immunohistochemical staining.ResultsAZD6244 could inhibit the tumor growth of NCI-H1993, but slightly inhibit the tumor growth of NCI-1975 and NCI-H460. Combining AZD6244 with BEZ235 markedly enhanced their antitumor effects and without any marked adverse events. Western blot analysis and immunohistochemical staining revealed that AZD6244 alone reduced ERK1/2 phosphorylation, angiogenesis, and tumor cell proliferation. Moreover, MEK1/2 inhibition resulted in decreased AKT phosphorylation in NCI-H1993 tumor model. BEZ235 also inhibited AKT phosphorylation as well as their downstream molecules in all three tumor models. The antiangiogenic effects were substantially enhanced when the agents were combined, which may due to the reduced expression of matrix metallopeptidase-9 in tumor tissues (MMP-9).ConclusionsIn this study, we evaluated therapy directed against MEK and PI3K/mTOR in distinct gefitinib-resistant NSCLC xenograft models. Combining AZD6244 with BEZ235 enhanced their antitumor and antiangiogenic effects. We concluded that the combination of a selective MEK inhibitor and a PI3K/mTOR inhibitor was effective in suppressing the growth of gefitinib-resistant tumors caused by EGFR T790M mutation, MET amplification, and KRAS/PIK3CA mutation. This new therapeutic strategy may be a practical approach in the treatment of these patients.

Cationic Lipid-Assisted Polymeric Nanoparticle Mediated GATA2 siRNA Delivery for Synthetic Lethal Therapy of KRAS Mutant Non-Small-Cell Lung Carcinoma

Synthetic lethal interaction provides a conceptual framework for the development of wiser cancer therapeutics. In this study, we exploited a therapeutic strategy based on the interaction between GATA binding protein 2 (GATA2) downregulation and the KRAS mutation status by delivering small interfering RNA targeting GATA2 (siGATA2) with cationic lipid-assisted polymeric nanoparticles for treatment of non-small-cell lung carcinoma (NSCLC) harboring oncogenic KRAS mutations. Nanoparticles carrying siGATA2 (NPsiGATA2) were effectively taken up by NSCLC cells and resulted in targeted gene suppression. NPsiGATA2 selectively inhibited cell proliferation and induced cell apoptosis in KRAS mutant NSCLC cells. However, this intervention was harmless to normal KRAS wild-type NSCLC cells and HL7702 hepatocytes, confirming the advantage of synthetic lethality-based therapy. Moreover, systemic delivery of NPsiGATA2 significantly inhibited tumor growth in the KRAS mutant A549 NSCLC xenograft murine model, suggesting the therapeutic promise of NPsiGATA2 delivery in KRAS mutant NSCLC therapy.

Abstract B30: Selective small molecule AXL inhibitor BGB324 overcomes acquired drug resistance in non-small cell lung carcinoma models.

Abstract Axl is a member of the TAM (Tyro3, Axl and Mer) family of receptor tyrosine kinases that regulate multiple cellular responses including cell survival, proliferation, and migration. Axl expression is associated with a variety of human cancers including non-small cell lung carcinoma (NSCLC), and is predictive of poor patient overall survival. Axl is induced by the epithelial-to-mesenchymal transition (EMT) gene program in cancer cells. Axl signaling is required to maintain EMT-associated features including invasiveness, metastasis, and can confer resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), as well as other chemotherapeutic agents. BGB324 is a potent, reversible and selective small molecule inhibitor of Axl that has recently entered into phase I clinical trials. We evaluated the effects of BGB324 on NSCLC cells in in vitro 3D assays and in mouse xenograft models, in combination with targeted and chemotherapeutic agents. BGB324 in combination with EGFR TKI erlotinib demonstrated a synergistic anti-proliferation effect on NCI-H1299 (mesenchymal, EGFR wild-type, erlotinib-resistant) human NSCLC cells in 3D culture. In mouse xenograft models using NCI-H1299 cells BGB324 treatment significantly enhanced the antitumor acitivity of Docetaxel. Similarly, using the mesenchymal NSCLC cell line A549 (EGFR wild-type), the combination of BGB324 with either erlotinib or anti-VEGF agent bevacizumab showed synergistic or additive anti-tumour activity. Furthermore, in HCC827 (EGFR mutant, erlotinib-sensitive) human NSCLC xenograft model, addition of BGB324 treatment strikely delayed the emergence of acquired resistance to erlotinib. Taken together, these data suggest the first-in-class selective Axl inhibitor BGB324 can overcome acquired resistance in in vivo models of NSCLC. Studies in human NSCLC patient-derived xenograft models and mechanisms of action are in progress. Citation Format: Katarzyna Wnuk-Lipinska, Gro Gausdal, Tone Sandal, Robin Frink, Stefan Hinz, Monica Hellesøy, Lavina Ahmed, Hallvard Haugen, Hallvard Haugen, Liang Xiao, Magnus Blø, David Micklem, John Minna, Rolf Brekken, Longen Zhou, James Lorens. Selective small molecule AXL inhibitor BGB324 overcomes acquired drug resistance in non-small cell lung carcinoma models. [abstract]. In: Proceedings of the AACR-IASLC Joint Conference on Molecular Origins of Lung Cancer; 2014 Jan 6-9; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2014;20(2Suppl):Abstract nr B30.

Anti-tumor efficacy of chitosan-g-poly(ethylene glycol) nanocapsules containing docetaxel: Anti-TMEFF-2 functionalized nanocapsules vs. non-functionalized nanocapsules

The development and evaluation of PEGylated chitosan (CS) nanocapsules (NCs) conjugated to a monoclonal antibody anti-TMEFF-2 (CS-PEG-anti-TMEFF-2 mAb NCs) for targeted delivery of docetaxel (DCX) is presented. CS-PEG-Biotin NCs, displaying biotin tags at their surface, were obtained and efficiently functionalized with an anti-TMEFF-2 mAb through a convenient avidin–biotin approach. Cell cycle analysis after treatment with different DCX-loaded CS-PEG NC formulations indicated that the encapsulated drug remained fully active, showing a similar functional behavior to free DCX. In vivo efficacy studies using a non-small cell lung carcinoma xenograft revealed that CS-PEG-anti-TMEFF-2 NCs resulted as effective as free DCX (Taxotere®). Interestingly, differences on the pharmacodynamic behavior among the different DCX formulations were observed. Thus, while free DCX exhibited a fast and short effect on tumor volume reduction, CS-PEG-anti-TMEFF-2 mAb NCs showed a delayed and prolonged action, with no significant side effects of treatments.