Patient-derived tumoroid models of pulmonary large-cell neuroendocrine carcinoma: a promising tool for personalized medicine and developing novel therapeutic strategies

Pulmonary large-cell neuroendocrine carcinoma (LCNEC), a disease with poor prognosis, is classified as pulmonary high-grade neuroendocrine carcinoma, along with small-cell lung cancer. However, given its infrequent occurrence, only a limited number of preclinical models have been established. Here, we established three LCNEC tumoroids for long-term culture. Whole-exome sequencing revealed that these tumoroids inherited genetic mutations from their parental tumors; two were classified as small-cell carcinoma (S-LCNEC) and one as non-small cell carcinoma (N-LCNEC). Xenografts from these tumoroids in immunodeficient mice mimicked the pathology of the parent LCNEC, and one reproduced the mixed-tissue types of combined LCNEC with a component of adenocarcinoma. Drug sensitivity tests using these LCNEC tumoroids enabled the evaluation of therapeutic agent efficacy. Based on translational research, we found that a CDK4/6 inhibitor might be effective for N-LCNEC and that Aurora A kinase inhibitors might be suitable for S-LCNEC or LCNEC with MYC amplification. These results highlight the value of preclinical tumoroid models in understanding the pathogenesis of rare cancers and developing treatments. LCNEC showed a high success rate in tumoroid establishment, indicating its potential application in personalized medicine.

Establishment and characterization of novel high mucus-producing lung tumoroids derived from a patient with pulmonary solid adenocarcinoma

Among mucus-producing lung cancers, invasive mucinous adenocarcinoma of the lung is a rare and unique subtype of pulmonary adenocarcinoma. Notably, mucus production may also be observed in the five subtypes of adenocarcinoma grouped under the higher-level diagnosis of Invasive Non-mucinous Adenocarcinomas (NMA). Overlapping pathologic features in mucus-producing tumors can cause diagnostic confusion with significant clinical consequences. In this study, we established lung tumoroids, PDT-LUAD#99, from a patient with NMA and mucus production. The tumoroids were derived from the malignant pleural effusion of a patient with lung cancer and have been successfully developed for long-term culture (> 11 months). Karyotyping by fluorescence in situ hybridization using an alpha-satellite probe showed that tumoroids harbored aneuploid karyotypes. Subcutaneous inoculation of PDT-LUAD#99 lung tumoroids into immunodeficient mice resulted in tumor formation, suggesting that the tumoroids were derived from cancer. Xenografts from PDT-LUAD#99 lung tumoroids reproduced the solid adenocarcinoma with mucin production that was observed in the patient's metastatic lymph nodes. Immunoblot analysis showed MUC5AC secretion into the culture supernatant of PDT-LUAD#99 lung tumoroids, which in contradistinction was barely detected in the culture supernatants of NCI-A549 and NCI-H2122 pulmonary adenocarcinoma cells known for their mucin-producing abilities. Here, we established a novel high-mucus-producing lung tumoroids from a solid adenocarcinoma. This preclinical model may be useful for elucidating the pathogenesis of mucus-producing lung cancer.

A surgical case of pulmonary adenocarcinoma in the right upper lobe associated with a systemic artery-to-pulmonary artery fistula

A 52-year-old female never-smoker with an abnormal shadow in the right lung detected on radiography was referred to our institution. Contrast-enhanced computed tomography revealed an irregular nodule in the upper lobe of the right lung, suggestive of a pulmonary vascular abnormality. Angiography revealed a direct communication between the right internal mammary artery (IMA) and the right upper lobe pulmonary artery branches, with dilated and tortuous vascular proliferation. As multiple branch arteries were seen flowing into the upper lobe from the IMA, transcatheter selective embolization of these vessels and right upper lobectomy by video-assisted thoracoscopic surgery were performed. Contrary to the clinical diagnosis, the pathological finding was a pulmonary adenocarcinoma of the right upper lobe. Additional lymph node dissection was performed later. We report an extremely rare and unprecedented case of pulmonary adenocarcinoma fed by the right IMA, with a literature review.

FOXA2 Cooperates with Mutant KRAS to Drive Invasive Mucinous Adenocarcinoma of the Lung

The endoderm-lineage transcription factor FOXA2 has been shown to inhibit lung tumorigenesis in in vitro and xenograft studies using lung cancer cell lines. However, FOXA2 expression in primary lung tumors does not correlate with an improved patient survival rate, and the functional role of FOXA2 in primary lung tumors remains elusive. To understand the role of FOXA2 in primary lung tumors in vivo, here, we conditionally induced the expression of FOXA2 along with either of the two major lung cancer oncogenes, EGFRL858R or KRASG12D, in the lung epithelium of transgenic mice. Notably, FOXA2 suppressed autochthonous lung tumor development driven by EGFRL858R, whereas FOXA2 promoted tumor growth driven by KRASG12D. Importantly, FOXA2 expression along with KRASG12D produced invasive mucinous adenocarcinoma (IMA) of the lung, a fatal mucus-producing lung cancer comprising approximately 5% of human lung cancer cases. In the mouse model in vivo and human lung cancer cells in vitro, FOXA2 activated a gene regulatory network involved in the key mucous transcription factor SPDEF and upregulated MUC5AC, whose expression is critical for inducing IMA. Coexpression of FOXA2 with mutant KRAS synergistically induced MUC5AC expression compared with that induced by FOXA2 alone. ChIP-seq combined with CRISPR interference indicated that FOXA2 bound directly to the enhancer region of MUC5AC and induced the H3K27ac enhancer mark. Furthermore, FOXA2 was found to be highly expressed in primary tumors of human IMA. Collectively, this study reveals that FOXA2 is not only a biomarker but also a driver for IMA in the presence of a KRAS mutation.

SIGNIFICANCE

FOXA2 expression combined with mutant KRAS drives invasive mucinous adenocarcinoma of the lung by synergistically promoting a mucous transcriptional program, suggesting strategies for targeting this lung cancer type that lacks effective therapies.

The complexity of EGFR exon 19 deletion and L858R mutant cells as assessed by proteomics, transcriptomics, and metabolomics

Most lung adenocarcinoma-associated EGFR tyrosine kinase mutations are either an exon 19 deletion (19Del) or L858R point mutation in exon 21. Although patients whose tumors contain either of these mutations exhibit increased sensitivity to tyrosine kinase inhibitors, progression-free and overall survival appear to be longer in patients with 19Del than in those with L858R. In mutant-transfected Ba/F3 cells, 19Del and L858R were compared by multi-omics analyses including proteomics, transcriptomics, and metabolomics. Proteome analysis identified increased plastin-2, TKT, PDIA5, and ENO1 expression in L858R cells, and increased EEF1G expression in 19Del cells. RNA sequencing showed significant differences between 19Del and L858R cells in 112 genes. Metabolome analysis showed that amino acids, adenylate, guanylate, NADPH, lactic acid, pyruvic acid glucose 6-phosphate, and ribose 5-phosphate were significantly different between the two mutant cells. Because GSH was increased with L858R, we combined osimertinib with the GSH inhibitor buthionine sulfoximine in L858R cells and observed synergistic effects. The complexity of EGFR 19Del and L858R mutant cells was demonstrated by proteomics, transcriptomics, and metabolomics analyses. Therapeutic strategies for lung cancer with different EGFR mutations could be considered because of their different metabolic phenotypes.

Neuroendocrine tumor secondary to pulmonary hypoplasia: A case report

Pulmonary hypoplasia is diagnosed during the perinatal period and is a cause of death in newborns. However, these developmental abnormalities are diagnosed in adulthood in some cases. A 70‐year‐old male smoker was diagnosed with stage IIIA pulmonary adenocarcinoma in the right upper lobe with right middle lobe hypoplasia. He subsequently underwent right upper and middle lobectomy with lymph node dissection by video‐assisted thoracoscopic surgery. In addition to an invasive adenocarcinoma in the right upper lobe, pathological examination of the hypoplastic lobe revealed neuroendocrine hyperplasia, as well as tumorlets and a typical carcinoid. Eight cases of pulmonary neuroendocrine tumors that developed from pulmonary hypoplasia have been reported to date. Interestingly, all but one case occurred in the right middle lobe. Neuroendocrine cell hyperplasia has been reported to develop in hypoplastic lungs postnatally; therefore, we speculated that the lesion was the origin of these neuroendocrine tumors. Moreover, the pathological findings suggested that atelectasis was involved in the pathogenesis of this rare condition. In adults, when lobar hypoplasia is diagnosed, neuroendocrine tumors should be anticipated.

Targeting ROR1 in combination with osimertinib in EGFR mutant lung cancer cells

Lung cancer that exhibits epidermal growth factor receptor (EGFR) gene mutation is sensitive to EGFR-tyrosine kinase inhibitors (TKIs), such as osimertinib. Receptor tyrosine kinase-like orphan receptor 1 (ROR1) may be involved in overcoming EGFR-TKI resistance. Growth inhibition, colony formation, apoptosis, and mRNA/protein levels in four osimertinib-sensitive and resistant cell lines transfected with small interfering RNA (siRNA) targeting ROR1 (siROR1) were evaluated. Cell growth and colony formation were suppressed and apoptosis was increased in all cell lines treated with siROR1. Although EGFR, AKT, and ERK phosphorylation were not suppressed in all cell lines, TGF-β2, AXL, CDH2, PARP1, PEG10, and TYMS mRNA expression levels were reduced. The combination of osimertinib with siROR1 was effective for the four cell lines, particularly in the two osimertinib-sensitive lines. In conclusion, targeting ROR1 in combination with osimertinib in EGFR mutant lung cancer may be a novel therapeutic option.

Clinical application of a lung cancer organoid (tumoroid) culture system

Despite high expectations for lung tumoroids, they have not been applied in the clinic due to the difficulty of their long-term culture. Here, however, using AO (airway organoid) media developed by the Clevers laboratory, we succeeded in generating 3 lung tumoroid lines for long-term culture (>13 months) from 41 lung cancer cases (primary or metastatic). Use of nutlin-3a was key to selecting lung tumoroids that harbor mutant p53 in order to eliminate normal lung epithelial organoids. Next-generation sequencing (NGS) analysis indicated that each lung tumoroid carried BRAFG469A, TPM3-ROS1 or EGFRL858R/RB1E737*, respectively. Targeted therapies using small molecule drugs (trametinib/erlotinib for BRAFG469A, crizotinib/entrectinib for TPM3-ROS1 and ABT-263/YM-155 for EGFRL858R/RB1E737*) significantly suppressed the growth of each lung tumoroid line. AO media was superior to 3 different media developed by other laboratories. Our experience indicates that long-term lung tumoroid culture is feasible, allowing us to identify NGS-based therapeutic targets and determine the responsiveness to corresponding small molecule drugs.

Bioelectrical impedance analysis for perioperative water management in adult cardiovascular valve disease surgery

PURPOSE

Bioelectrical impedance analysis (BIA) has been used recently to measure the body water of patients with acute heart failure. We used BIA in this study to better understand, and possibly identify a predictive marker for, perioperative water behavior in cardiac surgery patients.

METHODS

We measured body water and studied its behavior in 44 patients undergoing surgery for cardiac valvular disease at our hospital. Measurements included the levels of extracellular water (ECW), intracellular water (ICW), and total body water, the edema index (EI), and the ratio of ECW to total body water. The first measured EI was defined as the "preoperative EI" and the maximum as the "peak EI".

RESULTS

A negative correlation was found between the preoperative EI and the preoperative estimated glomerular filtration rate (eGFR) (R = 0.644, p < 0.001). Positive correlations were found between the peak EI and the ICU stay (R = 0.625, p < 0.001), the peak EI and the ventilation time (R = 0.366, p < 0.01), and the preoperative EI and the ICU stay (R = 0.464, p = 0.026).

CONCLUSION

The EI is possibly a predictive marker for perioperative water management in cardiac surgery.

Targeting ROR1 in combination with pemetrexed in malignant mesothelioma cells

OBJECTIVE

Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is overexpressed in a subset of malignant cells. However, it remains unknown whether ROR1 is targetable in malignant mesothelioma (MM). Therefore, in this study, we investigated the effects of ROR1 inhibition in mesothelioma cells.

MATERIALS AND METHODS

Growth inhibition, colony formation, apoptosis, and mRNA/protein levels using siRNA-transfected MM cells were evaluated. Cluster analysis using Gene Expression Omnibus repository of transcriptomic information was also performed.

RESULTS

Our results indicated that in three (H2052, H2452, and MESO-1) among four MM cell lines, ROR1 inhibition had anti-proliferative and apoptotic effects and suppressed the activation of AKT and STAT3. Although growth inhibition by siROR1 was minimal in another mesothelioma cell line (H28), colony formation was significantly suppressed. Microarray, quantitative polymerase chain reaction, and Western blot analyses showed that there were differences in the suppression of mRNA and proteins between H2452 and H28 cells transfected with siROR1 compared with those transfected with control siRNA. Cluster analysis further showed that MM tumors had relatively high ROR1 expression, although the cluster in them was different from that in MM cell lines. Thymidylate synthase, a target of pemetrexed, was downregulated in H2452 cells transfected with siROR1. Accordingly, a combination of pemetrexed with siROR1 was found to be effective in the three MM cell lines we studied.

CONCLUSION

Our findings may provide novel therapeutic insight into the treatment of advanced MM.

A case report of left lower lobe segmentectomy for pulmonary metastasis from retroperitoneal liposarcoma

BACKGROUND

The principle treatment for retroperitoneal liposarcoma is surgical resection, however there are many cases of recurrence. In addition to local recurrence, retroperitoneal liposarcoma, particularly dedifferentiated liposarcoma is known to occasionally cause lung metastases.

CASE REPORT

A 72-year-old woman with a diagnosis of retroperitoneal liposarcoma and probable right upper lobe early pulmonary adenocarcinoma underwent sequential local tumor resection and right upper lobectomy. Twenty months after liposarcoma resection, a computed tomography (CT) scan of the chest revealed a nodule located in the left lower lobe. A CT-guided biopsy was performed and she was subsequently diagnosed with pulmonary metastasis from retroperitoneal liposarcoma. The nodule enlarged chronologically, however a left lower lobectomy could not be performed because respiratory function after the right upper lobectomy was not sufficient. Therefore, in order to preserve the left superior segment (S6), the basal segments (S8+S9+S10) were resected. Seven months after the surgery, she is living a self-reliant life without recurrence of liposarcoma.

CONCLUSION

Here we have reported a case of pulmonary metastasis from retroperitoneal liposarcoma following limited surgery. In cases where respiratory function is limited, lower lobe segmentectomy can be an effective treatment. For the treatment of a single pulmonary metastasis from retroperitoneal liposarcoma, metastasectomy was considered to be effective as long as no local recurrence was seen after initial primary tumor resection.

Abstract 3056: Development of an integrated CRISPR interference system targeting ΔNp63 to treat lung and esophageal squamous cell carcinoma

TP63 encodes two different transcripts that have opposite functions in transcriptional control. One transcript encodes TAp63 that is functionally similar to the tumor suppressor TP53. The other transcript, ΔNp63, lacks the transcription-activating domain of TAp63 and has been proposed to function as a potent oncogene in squamous cell carcinomas. In this study, we have developed an integrated CRISPR interference system to selectively suppress ΔNp63 and we have termed this system CRISPRiΔNp63. We engineered the CRISPRi using tandemized guide RNA expression cassettes to target the 50 to 100 bp downstream region of the transcription start site of ΔNp63 and we used inactivated Cas9 linked to the transcription repression module Krüppel-associated box repressor domain. The plasmid vector harboring CRISPRiΔNp63 repressed ΔNp63 transcriptional activity in lung and esophageal squamous cell carcinoma cells that express ΔNp63. Moreover, an all-in-one adenoviral vector containing tandemized gRNAs and the dCas9/KRAB expression cassette, Ad-CRISPRiΔNp63, suppressed ΔNp63 expression in squamous cell carcinomas cells. Ad-CRISPRiΔNp63 effectively decreased cell proliferation and colony formation and induced apoptosis in lung and esophageal squamous cell carcinoma cells in vitro. Moreover, the all-in-one vector significantly inhibited tumor growth in a lung squamous cell carcinoma xenograft mouse model in vivo. These results indicate that ΔNp63 suppression by CRISPRiΔNp63 might be an effective strategy for the treatment of lung and esophageal squamous cell carcinoma.

Citation Format: Masakazu Yoshida, Etsuko Yokota, Tetsushi Sakuma, Nagio Takigawa, Toshikazu Ushijima, Takashi Yamamoto, Yoshio Naomoto, Takuya Fukazawa, Tomoki Yamatsuji. Development of an integrated CRISPR interference system targeting ΔNp63 to treat lung and esophageal squamous cell carcinoma [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 3056.

Three-Component Repurposed Technology for Enhanced Expression: Highly Accumulable Transcriptional Activators via Branched Tag Arrays

In the past few years, several types of artificial transcriptional activator, based on CRISPR-Cas9, have been developed and refined. Of these, in synergistic activation mediator and SunTag systems, the effector proteins, expressed in trans, can be recruited to the target sites via the MS2 RNA-binding system and GCN4-scFv antibody system, respectively. Here, we report a strong transcriptional activation system achieved by fusing GCN4 repeat to MS2 coat protein to accumulate numbers of activators, fused to scFv antibodies. By targeting the CDH1 gene, we show that our novel system, named “TREE,” results in a greater effect of activating exogenous reporter and endogenous gene. Moreover, by targeting another gene, RANKL, we consistently show the superiority of the TREE system with fewer single-guide RNAs compared to conventional systems. Our TREE system is a promising tool for transcriptional activation and can potentially contribute to other dCas9-mediated technologies such as epigenome editing and chromosome visualization.

Abstract 1922: Targeted silencing of SOX2 by an artificial transcription factor showed antitumor effect in lung and esophageal squamous cell carcinoma

S0X2 is a transcription factor essential for early mammalian development and for the maintenance of stem cells. Recently, SOX2 was identified as a lineage specific oncogene, recurrently amplified and activated in lung and esophageal squamous cell carcinoma (SCC). In this study, we have developed a zinc finger-based artificial transcription factor (ATF) to selectively suppress SOX2 expression in cancer cells and termed the system ATF/SOX2. We engineered the ATF using six zinc finger arrays designed to target a 19 bp site in the SOX2 distal promoter and a KOX transcriptional repressor domain. A recombinant adenoviral vector Ad- ATF/SOX2 that expresses ATF/SOX2 suppressed SOX2 at the mRNA and protein levels in lung and esophageal SCC cells expressing SOX2. In these kinds of cells, Ad-ATF/SOX2 decreased cell proliferation and colony formation more effectively than the recombinant adenoviral vector Ad-shSOX2, which expresses SOX2 short hairpin RNA (shSOX2). Ad-ATF/SOX2 induced the cell cycle inhibitor CDKN1A more strongly than Ad-shSOX2. Importantly, the ATF did not suppress the cell viability of normal human cells. Moreover, Ad-ATF/SOX2 effectively inhibited tumor growth in a lung SCC xenograft mouse model. These results indicate that ATF/SOX2 would lead to the development of an effective molecular-targeted therapy for lung and esophageal SCC.

Citation Format: Etsuko Yokota, Tomoki Yamatsuji, Munenori Takaoka, Minoru Haisa, Nagio Takigawa, Noriko Miyake, Tomoko Ikeda, Tomoaki Mori, Ohno Serika, Takashi Sera, Takuya Fukazawa, Yoshio Naomoto. Targeted silencing of SOX2 by an artificial transcription factor showed antitumor effect in lung and esophageal squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1922.

Development of an integrated CRISPRi targeting ΔNp63 for treatment of squamous cell carcinoma

TP63 encodes TAp63, which is functionally similar to the tumor suppressor TP53, and ΔNp63, which lacks the transcription-activating domain of TAp63 and appears potently oncogenic in squamous cell carcinomas (SCCs). In this study, we developed an integrated CRISPR interference (CRISPRi) system to selectively suppress ΔNp63 (CRISPRiΔNp63). We engineered this CRISPRi using tandemized guide RNA expression cassettes that targeted the 50 to 100 bp downstream of the transcription start site of ΔNp63 in combination with inactivated Cas9 linked to the transcription repression module Krüppel-associated box repressor domain. The plasmid vector harboring CRISPRiΔNp63 repressed ΔNp63 transcription in lung and esophageal SCC cells. Likewise, Ad-CRISPRiΔNp63, an all-in-one adenoviral vector containing the tandemized gRNAs and dCas9/KRAB expression cassette suppressed ΔNp63 expression in SCC cells. Ad-CRISPRiΔNp63 also effectively decreased cell proliferation and colony formation and induced apoptosis in lung and esophageal SCC cells in vitro and significantly inhibited tumor growth in a mouse lung SCC xenograft model in vivo. These results indicate that ΔNp63 suppression using CRISPRiΔNp63 may be an effective strategy for treating lung and esophageal SCC.

Targeted silencing of SOX2 by an artificial transcription factor showed antitumor effect in lung and esophageal squamous cell carcinoma

SOX2 is a transcription factor essential for early mammalian development and for the maintenance of stem cells. Recently, SOX2 was identified as a lineage specific oncogene, recurrently amplified and activated in lung and esophageal squamous cell carcinoma (SCC). In this study, we have developed a zinc finger-based artificial transcription factor (ATF) to selectively suppress SOX2 expression in cancer cells and termed the system ATF/SOX2. We engineered the ATF using six zinc finger arrays designed to target a 19 bp site in the SOX2 distal promoter and a KOX transcriptional repressor domain. A recombinant adenoviral vector Ad-ATF/SOX2 that expresses ATF/SOX2 suppressed SOX2 at the mRNA and protein levels in lung and esophageal SCC cells expressing SOX2. In these kinds of cells, Ad-ATF/SOX2 decreased cell proliferation and colony formation more effectively than the recombinant adenoviral vector Ad-shSOX2, which expresses SOX2 short hairpin RNA (shSOX2). Ad-ATF/SOX2 induced the cell cycle inhibitor CDKN1A more strongly than Ad-shSOX2. Importantly, the ATF did not suppress the cell viability of normal human cells. Moreover, Ad-ATF/SOX2 effectively inhibited tumor growth in a lung SCC xenograft mouse model. These results indicate that ATF/SOX2 would lead to the development of an effective molecular-targeted therapy for lung and esophageal SCC.

Gene signature driving invasive mucinous adenocarcinoma of the lung

Though invasive mucinous adenocarcinoma of the lung (IMA) is pathologically distinctive, the molecular mechanism driving IMA is not well understood, which hampers efforts to identify therapeutic targets. Here, by analyzing gene expression profiles of human and mouse IMA, we identified a Mucinous Lung Tumor Signature of 143 genes, which was unexpectedly enriched in mucin-producing gastrointestinal, pancreatic, and breast cancers. The signature genes included transcription factors FOXA3, SPDEF, HNF4A, mucins MUC5AC, MUC5B, MUC3, and an inhibitory immune checkpoint VTCN1/B7-H4 (but not PD-L1/B7-H1). Importantly, induction of FOXA3 or SPDEF along with mutant KRAS in lung epithelium was sufficient to develop benign or malignant mucinous lung tumors, respectively, in transgenic mice. FOXA3 and SPDEF induced MUC5AC and MUC5B, while HNF4A induced MUC3 in human mucinous lung cancer cells harboring a KRAS mutation. ChIP-seq combined with CRISPR/Cas9 determined that upstream enhancer regions of the mucin genes MUC5AC and MUC5B, which were bound by SPDEF, were required for the expression of the mucin genes. Here, we report the molecular signature and gene regulatory network driving mucinous lung tumors.

Abstract 2085: Development of a novel targeted therapy for malignant mesothelioma carcinoma by a midkine inhibitor

Malignant pleural mesothelioma is an aggressive tumor of mesenchymal origin and is increasing worldwide as a result of widespread exposure to asbestos. The median survival of patients with mesothelioma from time of diagnosis ranges between 1 and 2 years. The mortality is expected to increase, at least until 2020, which is mainly due to the long latency (30-50 years) of the disease. Despite considerable advances in the understanding of its pathogenesis and etiology, malignant mesothelioma remains largely unresponsive to standard modalities of cancer therapy. Thus, there is an urgent need for new therapeutic options for mesothelioma.Midkine (MDK) is a heparin-binding growth factor that is highly expressed in many malignant tumors, including lung cancers. We have previously reported that a MDK inhibitor, iMDK, suppresses non-small cell lung cancer expressing MDK without harming normal cells. Importantly, iMDK inhibits the PI3 kinase / Akt pathway and induces apoptosis in MDK expressing non-small cell lung cancer cells. In the present study, we have investigated the antitumor effect of iMDK against malignant mesothelioma both in vitro and in vivo. 48 hours after treatment, iMDK dose-dependently inhibited cell growth of MDK expressing malignant mesothelioma cells. iMDK also suppressed colony formation of MSTO-211H mesothelioma cells. TUNEL positive cells were significantly increased in MSTO-211H cells 48 hours after iMDK treatment in a dose-dependent manner, confirming the induction of apoptosis in mesothelioma cells by iMDK. Combination treatment of iMDK and Bcl-2 inhibitor ABT-263 is more effective than each drug alone in MSTO-211H mesothelioma cells. Moreover, systemic administration of iMDK significantly inhibited tumor growth in a mesothelioma xenograft tumor in vivo. Inhibition of MDK with iMDK provides a potential therapeutic approach for the treatment of malignant mesothelioma that is driven by MDK.

Citation Format: Takuya Fukazawa, Yuitaka Maeda, Tomoki Yamatsuji, Munenori Takaoka, Masakazu Yoshida, Naomasa Ishida, Miki Iwai, Etsuko Yokota, Takuro Yukawa, Minoru Haisa, Noriko Miyake, Tomoko Ikeda, Nagio Takigawa, Jeffery Whitsett, Yoshio Naomoto. Development of a novel targeted therapy for malignant mesothelioma carcinoma by a midkine inhibitor [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 2085. doi:10.1158/1538-7445.AM2017-2085

A Case of Birt-Hogg-Dubé (BHD) Syndrome Harboring a Novel Folliculin (FLCN) Gene Mutation

Patient: Female, 56

Final Diagnosis: Birt-Hogg-Dubé syndrome

Symptoms: Dyspnea

Medication: —

Clinical Procedure: —

Specialty: Pulmonology

Abstract 2019: SOX2 silencing upregulates CDKN1A and suppresses growth of lung squamous cell carcinoma

SOX2 is a master pluripotency controller that was recently identified as a novel major oncogene, recurrently amplified and activated in lung squamous cell carcinoma (lung SCC). Then, transcriptional downstream targets of SOX2 have been actively investigated; however, such targets are often cell line specific. Here, in order to identify highly consensus SOX2 downstream genes in lung SCC cells, we used RNA-seq data from 178 lung SCC specimens (containing tumor and tumor-associated cells) and analyzed the correlation between SOX2 and previously-reported SOX2-controlled genes in lung SCC. In addition, we used another RNA-seq dataset from 105 non-small cell lung cancer cell lines (NSCLC; including lung SCC cells) and again analyzed the correlation between SOX2 and the reported SOX2-controlled genes in the NSCLC cell lines (no tumor-associated cells). We combined the two analyses and identified genes commonly correlated with SOX2 in both datasets. Among the 99 genes reported as SOX2 downstream and/or correlated genes, we found 4 negatively-correlated (e.g., CDKN1A) and 11 positively-correlated genes with SOX2. We used biological studies to demonstrate that CDKN1A was suppressed by SOX2 in lung SCC cells. G1 cell cycle arrest induced by SOX2 siRNA was rescued by CDKN1A siRNA. These results indicate that the tumorigenic effect of SOX2 in lung SCC cells is mediated in part by suppression of CDKN1A.

Citation Format: Takuya Fukazawa, Tomokoki Yamatsuji, Munenori Takaoka, Etsuko Yokota, Minoru Haisa, Naomasa Ishida, Masakazu Yoshida, Noriko Miyake, Nagio Takigawa, Yutaka Maeda, Yoshio Naomoto. SOX2 silencing upregulates CDKN1A and suppresses growth of lung squamous cell carcinoma. [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 2019.

HLA-DPB1*0501 is not uniquely associated with opticospinal multiple sclerosis in Japanese patients. Important role of DPB1*0301

Apart from its unique lesion distribution pattern, the opticospinal form of multiple sclerosis (OSMS) is distinct among Japanese patients who satisfy the diagnostic criteria of MS. OSMS has been suggested to be strongly associated with HLA-DPB1*0501 in Japanese. However, association of DPB1*0301 with non-OSMS and lack of DPB1*0301 in OSMS were also reported. To verify the role of DPB1*0501 and DPB1*0301 in Japanese MS patients we determined the frequencies of these alleles in 26 patients with OSMS, 167 with non-OSMS and 156 normal subjects, who were all residents of Hokkaido, the northernmost island of Japan. All (100%) OSMS were negative for DPB1*0301 while 32 (19%) of the non-OSMS were positive for the allele. In DPB1*0301-negatives, the frequencies of DPB1*0501 in OSMS (85%) and non-OSMS (82%) were similar, but both were higher than in the controls (66%). In DPB1*0301-positives, the frequency of DPB1*0501 was low but similar in non-OSMS (12/32; 38%) and controls (6/14; 43%). Periventricular white matter lesions (PVL) were noted in 31 of 32 (97%) DPB1*0301-positive non-OSMS patients but in only 22 out of 135 (16%) DPB1*0301-negative non-OSMS patients and two out of 26 (8%) OSMS patients. Our findings indicate that DPB1*0501 plays an important role in the development of MS in general, but not in OSMS. The strong association of DPB1*0501 with OSMS may be due to the over-representation of the DPB1*0301 allele among individuals in the non-OSMS group. In addition, DPB1*0301 might be relevant to the development of periventricular lesions in Japanese patients with MS.

Expression and activity analyses of CTLA4 in peripheral blood lymphocytes in systemic lupus erythematosus patients

The objective of this study was to determine the expression and activity of CTLA4 in T-cells of systemic lupus erythematosus (SLE) patients. Expression of CTLA4 on freshly isolated peripheral blood T-cells was evaluated in 33 SLE patients and 25 controls using flow cytometry.The T-cells from 19 SLE patients and 22 controls were stimulated and cultured with Chinese hamster ovary cells expressing CD80 (CHO-CD80) or with CHO cells. T-cell proliferation was determined with [3H] thymidine incorporation (CPM), and the inhibitory effect of CTLA4 on T-cell proliferation was evaluated by the ratio of CPM for T-cells with CHO -CD80 cells to that of T-cells with CHO cells (the CHO -CD80/CHO ratio). IntracellularCTLA4 expressionin freshly isolated peripheral blood T-cells was significantly higher in SLE patients than the controls (P < 0.05), but there was no correlation with clinical features or disease activity. The CHO -CD80/CHO ratio of SLE patients was significantly higher than that of the controls(P < 0.05). Among SLE patients, the CHO -CD80/CHO ratio of patients with lupus nephritis was significantly higher than that of patients without lupus nephritis (P < 0.05). In conclusion, our data suggest that CTLA4 expression is not impaired in SLE patients, but there is a possibility of decreased inhibitory effect of CTLA4 involved in the pathogenesis of SLE.

Aqueous-Medium Carbon-Carbon Bond-Forming Radical Reactions Catalyzed by Excited Rhodamine B as a Metal-Free Organic Dye under Visible Light Irradiation

The utility of rhodamine B as a water-soluble organic photocatalyst was studied in the cascade radical addition-cyclization-trapping reactions under visible light irradiation. In the presence of (i-Pr)2NEt, the electron transfer from the excited rhodamine B to perfluoroalkyl iodides proceeded smoothly to promote the carbon-carbon bond-forming radical reactions in aqueous media. When i-C3F7I was employed as a radical precursor, the aqueous-medium radical reactions proceeded even in the absence of (i-Pr)2NEt. In these reactions, the direct electron transfer from the excited singlet state of rhodamine B would take place. Furthermore, the cleavage of the C-I bond in less reactive i-PrI could be achieved by the reductive electron transfer from the excited rhodamine B, which was confirmed by the fluorescence quenching of rhodamine B with the addition of i-PrI.

Novel Midkine Inhibitor iMDK Inhibits Tumor Growth and Angiogenesis in Oral Squamous Cell Carcinoma

Midkine is a heparin-binding growth factor highly expressed in various human malignant tumors. However, its role in the growth of oral squamous cell carcinoma is not well understood. In this study, we analyzed the antitumor effect of a novel midkine inhibitor (iMDK) against oral squamous cell carcinoma. Administration of iMDK induced a robust antitumor response and suppressed cluster of differentiation 31 (CD31) expression in oral squamous cell carcinoma HSC-2 cells and SAS cells xenograft models. iMDK inhibited the proliferation of these cells dose-dependently, as well as the expression of midkine and phospho-extracellular signal-regulated kinase in HSC-2 and SAS cells. Moreover, iMDK significantly inhibited vascular endothelial growth factor and induced tube growth of human umbilical vein endothelial cells in a dose-dependent fashion. These findings suggest that midkine is critically involved in oral squamous cell carcinoma and iMDK can be effectively used for the treatment of oral squamous cell carcinoma.

Abstract 2694: Esophageal cancer exhibits a resistance to the chemical inhibition of IGF-1R with a maintained Ras-MAPK activity

The type 1 insulin-like growth factor receptor (IGF-1R) and its associated signaling system play a significant role in carcinogenesis and progression of gastrointestinal malignancies, and thus have provoked great interest as a promising target for cancer treatment. The aim of our study was to assess the effects of a novel IGF-1R inhibitor, NVP-AEW541, on the cell proliferation and signal transduction of esophageal squamous cell carcinoma. Five human esophageal squamous carcinoma cell lines (TE-1, TE-4, TE-8, TE-10 and T.Tn) were treated with this inhibitor and the IC50 of NVP-AEW541 for each cell line was more than 1μM, exhibiting that these cells were less sensitive to this compound. The activation of IGF-1R and AKT were dose dependently blocked by NVP-AEW541. However, the activities of the key molecules in Ras-MAPK pathway was not significantly inhibited by NVP-AEW541 without any major mutation of Ras. These results indicate that esophageal squamous cell carcinoma may be resistant to targeting IGF-IR due to its maintenance of Ras-MAPK signaling. Thus, to explore the potential mechanism of resistance will contribute to the therapeutic application for NVP-AEW541.

Citation Format: Munenori Takaoka, XiaoHong Bao, Huifang Hao, Naomasa Ishida, Takuya Fukazawa, Tomoki Yamatsuji, Minoru Haisa, Yoshio Naomoto. Esophageal cancer exhibits a resistance to the chemical inhibition of IGF-1R with a maintained Ras-MAPK activity. [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 2694. doi:10.1158/1538-7445.AM2015-2694

Abstract 3616: Development of a Sox2 targeting therapy for the treatment of lung squamous cell carcinoma

Despite the recent development of several effective molecular targeted agents, lung cancer is the most common cause of cancer related deaths worldwide. Recently, molecular targeted therapies for pulmonary adenocarcinoma with mutant EGFR or ALK fusions have reduced non-tumor toxicity and have extended patient survival time compared to conventional chemotherapies. However, the development of molecular targeting drugs for NSCLC has made apparent the fact that histology is an important factor and molecularly targeted therapies have been more effective in pulmonary adenocarcinoma than in lung squamous cell carcinoma. Therefore, specific therapies that target lung squamous cell carcinoma are desperately needed.

Sox2 is a master pluripotency controller that was recently identified as a novel major oncogene, recurrently amplified and activated in lung squamous cell carcinoma. Immunohistochemistry shows that Sox2 expression is seen in approximately 55% of human pulmonary adenocarcinoma sections. On the other hand Sox2 expression is detected in more than 90% of lung squamous cell carcinoma sections. Inhibition of Sox2 by siRNA suppresses cell viability and colony formation of Sox2 expressing EBC2 and LK2 lung squamous cell carcinoma cells. Moreover, Sox2 siRNA inhibits lung squamous cell carcinoma growth in vivo in a xenograft mouse model derived from EBC2 cells. Flowcytometric analysis demonstrated that Annexin V positive and PI negative cell populations were not changed 48 hours after Sox2 silencing in EBC2 lung squamous cell carcinoma cells. Microarray analysis demonstrated that the expression of several cell cycle related genes were changed after Sox2 silencing in Sox2 expressing lung squamous cell carcinoma cells. Cell cycle analysis showed that Sox2 silencing significantly increased the G1 population in the cells. These results indicate that Sox2 silencing might produce an antitumor effect via G1 cell cycle arrest.

Citation Format: Naomasa Ishida, Takuya Fukazawa, Munenori Takaoka, Tomoki Yamatsuji, Ichiro Morita, Minoru Haisa, Nagio Takaoka, Yoshio Naomoto. Development of a Sox2 targeting therapy for the treatment of lung squamous cell carcinoma. [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 3616. doi:10.1158/1538-7445.AM2015-3616

A novel PI3K inhibitor iMDK suppresses non-small cell lung Cancer cooperatively with A MEK inhibitor

The PI3K-AKT pathway is expected to be a therapeutic target for non-small cell lung cancer (NSCLC) treatment. We previously reported that a novel PI3K inhibitor iMDK suppressed NSCLC cells in vitro and in vivo without harming normal cells and mice. Unexpectedly, iMDK activated the MAPK pathway, including ERK, in the NSCLC cells. Since iMDK did not eradicate such NSCLC cells completely, it is possible that the activated MAPK pathway confers resistance to the NSCLC cells against cell death induced by iMDK. In the present study, we assessed whether suppressing of iMDK-mediated activation of the MAPK pathway would enhance anti-tumorigenic activity of iMDK. PD0325901, a MAPK inhibitor, suppressed the MAPK pathway induced by iMDK and cooperatively inhibited cell viability and colony formation of NSCLC cells by inducing apoptosis in vitro. HUVEC tube formation, representing angiogenic processes in vitro, was also cooperatively inhibited by the combinatorial treatment of iMDK and PD0325901. The combinatorial treatment of iMDK with PD0325901 cooperatively suppressed tumor growth and tumor-associated angiogenesis in a lung cancer xenograft model in vivo. Here, we demonstrate a novel treatment strategy using iMDK and PD0325901 to eradicate NSCLC.

Preclinical evaluation of microRNA-34b/c delivery for malignant pleural mesothelioma

The microRNA-34s (miR-34s) have p53 response elements in their 5'-flanking regions and demonstrate tumor-suppressive functions. In malignant pleural mesothelioma (MPM), we previously reported that expression of miR-34b and miR-34c (miR-34b/c) was frequently downregulated by methylation in MPM cell lines and primary tumors. The forced overexpression of miR-34b/c showed significant antitumor effects with the induction of apoptosis in MPM cells. In this study, we examined the in vivo antitumor effects of miR-34b/c using adenovirus vector on MPM. We subcutaneously transplanted NCI-H290, a human MPM cell line, into BALB/C mice and injected adenovirus vector expressing miR-34b/c, luciferase driven by the cytomegalovirus promoter (Ad-miR-34b/c or Ad-Luc), or PBS control into tumors over 5mm in diameter. A statistically significant growth inhibition of the tumor volume was observed in the Ad-miR-34b/c group from day 6 onward compared to the Ad-Luc group. The inhibition rate of Ad-miR-34b/c, compared to the tumor volume treated with Ad-Luc, was 58.6% on day 10 and 54.7% on day13. Our results indicate that adenovirus-mediated miR-34b/c gene therapy could be useful for the clinical treatment of MPM.

Control of algal production in a high rate algal pond: investigation through batch and continuous experiments

For decades, arid and semi-arid regions in Africa have faced issues related to water availability for drinking, irrigation and livestock purposes. To tackle these issues, a laboratory scale greywater treatment system based on high rate algal pond (HRAP) technology was investigated in order to guide the operation of the pilot plant implemented in the 2iE campus in Ouagadougou (Burkina Faso). Because of the high suspended solids concentration generally found in effluents of this system, the aim of this study is to improve the performance of HRAPs in term of algal productivity and removal. To determine the selection mechanism of self-flocculated algae, three sets of sequencing batch reactors (SBRs) and three sets of continuous flow reactors (CFRs) were operated. Despite operation with the same solids retention time and the similarity of the algal growth rate found in these reactors, the algal productivity was higher in the SBRs owing to the short hydraulic retention time of 10 days in these reactors. By using a volume of CFR with twice the volume of our experimental CFRs, the algal concentration can be controlled during operation under similar physical conditions in both reactors.

A case of acute superior mesenteric artery embolism with severe ischemic liver injury successfully treated by endovascular treatment

We describe an interesting clinical course of a patient who developed severe ischemic liver injury due to acute embolism of the superior mesenteric artery (SMA) and celiac artery. A 70-year-old man was hospitalized for abdominal pain and diarrhea. Abdominal computed tomography demonstrated a variant common hepatic artery arising from the SMA and multiple thromboembolic occlusions of visceral arteries, including the SMA and celiac artery. Laboratory data showed markedly elevated hepatic enzymes, which increased after admission despite the initiation of systemic anticoagulant and thrombolytic therapy. The patient was successfully treated by endovascular recanalization of the SMA occlusion via transcatheter embolus aspiration, thrombolysis, balloon angioplasty, and stent placement. Severe ischemic liver injury may occur in the setting of synchronous embolism of the SMA and celiac artery, and these phenomena may have a critical impact on the choice of treatment strategies and prognosis. Endovascular treatment appears to an effective treatment option.

Novel HSP90 inhibitor NVP-AUY922 enhances the anti-tumor effect of temsirolimus against oral squamous cell carcinoma

BACKGROUND AND AIM

Heat shock protein 90 (HSP90) and mammalian target of rapamycin (mTOR) are involved in the molecular pathogenesis of advanced oral squamous cell carcinoma. HSP90 inhibitors are capable of effectively interfering with multiple signaling pathways, including the mTOR signaling pathway. However, the combined effects of HSP90 and mTOR inhibitors on oral squamous cell carcinoma are still unknown. In this study, we investigated the dual treatment of the novel HSP90 inhibitor NVP-AUY922 and temsirolimus against oral squamous cell carcinoma.

MATERIALS AND METHODS

The effect of the combination of NVP-AUY922 and temsirolimus on oral squamous cell carcinoma in vitro and in vivo was determined by MTS assay and mouse xenograft models. The effect of the combination on angiogenesis was determined by tube formation assay and angioreactor.

RESULTS

The combination treatment of NVP-AUY922 and temsirolimus significantly inhibited the proliferation of SAS oral squamous cell carcinoma cells in vitro and suppressed the growth of oral squamous cell carcinoma xenografts in vivo. We have clearly shown that the combination treatment of NVP-AUY922 and temsirolimus inhibited vascular formation both in vitro and in vivo. Moreover, the combination treatment of NVP-AUY922 and temsirolimus prolonged the survival rate in mice xenografted with oral squamous cell carcinoma.

CONCLUSIONS

Here, we showed the activity of a combination of mTOR and HSP90 inhibitors for the treatment of advanced oral squamous carcinoma.

Inhibition of the growth factor MDK/midkine by a novel small molecule compound to treat non-small cell lung cancer

Midkine (MDK) is a heparin-binding growth factor that is highly expressed in many malignant tumors, including lung cancers. MDK activates the PI3K pathway and induces anti-apoptotic activity, in turn enhancing the survival of tumors. Therefore, the inhibition of MDK is considered a potential strategy for cancer therapy. In the present study, we demonstrate a novel small molecule compound (iMDK) that targets MDK. iMDK inhibited the cell growth of MDK-positive H441 lung adenocarcinoma cells that harbor an oncogenic KRAS mutation and H520 squamous cell lung cancer cells, both of which are types of untreatable lung cancer. However, iMDK did not reduce the cell viability of MDK-negative A549 lung adenocarcinoma cells or normal human lung fibroblast (NHLF) cells indicating its specificity. iMDK suppressed the endogenous expression of MDK but not that of other growth factors such as PTN or VEGF. iMDK suppressed the growth of H441 cells by inhibiting the PI3K pathway and inducing apoptosis. Systemic administration of iMDK significantly inhibited tumor growth in a xenograft mouse model in vivo. Inhibition of MDK with iMDK provides a potential therapeutic approach for the treatment of lung cancers that are driven by MDK.

Abstract 3248: Oral administration of FAK inhibitor TAE226 inhibits the progression of peritoneal dissemination of colorectal cancer

Peritoneal dissemination is one of the most terrible types of colorectal cancer progression. Focal adhesion kinase (FAK) plays a crucial role in the biological processes of cancer, such as cell attachment, migration, proliferation and survival, all of which are essential for the progression of peritoneal dissemination. Since we and other groups have reported that the inhibition of FAK activity exhibited a potent anticancer effect in several cancer models, we hypothesized that TAE226, a novel ATP-competitive tyrosine kinase inhibitor designed to target FAK, can prevent the occurrence and progression of peritoneal dissemination. In vitro, TAE226 greatly inhibited the proliferation and migration of HCT116 colon cancer cells, while their adhesion on the matrix surface was minimally inhibited when FAK activity and expression was suppressed by TAE226 and siRNA. In vivo, when HCT116 cells were intraperitoneally inoculated in mice, the cells could attach to the peritoneum and begin to grow within 24 h regardless of the pretreatment of cells with TAE226 or FAK-siRNA, suggesting that FAK is not essential, at least for the initial integrin-matrix contacts. Interestingly, the treatment of mice before and after inoculation significantly suppressed the cell attachment to the peritoneum. Furthermore, oral administration of TAE226 greatly reduced the size of disseminated tumors and prolonged survival in tumor-bearing mice. Taken together, a possible strategy for inhibiting peritoneal dissemination by targeting FAK, including TAE226, appears to be applicable through anti-proliferative and anti-invasion/anti-migration mechanisms.

Citation Format: Munenori Takaoka, Hui-fang Hao, Xiao-hong Bao, Yasuko Tomono, Kazufumi Sakurama, Toshiaki Ohara, Takuya Fukazawa, Tomoki Yamatsuji, Yoshio Naomoto. Oral administration of FAK inhibitor TAE226 inhibits the progression of peritoneal dissemination of colorectal cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3248. doi:10.1158/1538-7445.AM2013-3248

Abstract 2180: Development of novel targeted therapies for non-small cell carcinoma by novel Midkine inhibitors

In the past few years a subset of driver mutations has been identified in non-small cell lung carcinoma (NSCLC), the most common type of lung adenocarcinoma. These driver mutations have differential sensitivities to various targeted therapies. The number of identified mutations in lung adenocarcinomas is limited, therefore identification of more molecular targets is needed in order to develop new treatments for NSCLCs. Efforts to find target mutations in lung adenocarcinoma with KRAS mutations are especially important because such adenocarcinomas account for 20% of lung adenocarcinoma, the most frequent type of lung adenocarcinomas.

Midkine is a heparin-binding cytokine that is induced by retinoic acid in embryonal carcinoma cells. It is involved in the development of cancer because of its mitogenic effect, promotion of angiogenesis, anti-apoptotic activity and transforming activity. Midkine expression is increased in various malignant tumors, including lung, esophageal, stomach, colon, hepatocellular, breast and pancreatic carcinomas, when compared with the level of expression in normal tissues. In a proof-of-principle effort to identify novel compounds that inhibit Midkine expression, we recently conducted cell-based high-throughput screening (HTS) of 44,000 compounds in the compound library using the Midkine promoter. We identified sixteen small molecules that inhibit Midkine promoter activity. Significantly, many of these inhibitors, which reduced Midkine protein, also inhibited proliferation in non-small cell lung cancer cells which express high levels of endogenous Midkine. We assigned the name iMDK1 to one of these compounds and assessed its ability to target non-small cell lung cancer cells. 48 hours after treatment, iMDK1 dose-dependently inhibited cell growth of Midkine expressing H441 pulmonary adenocarcinoma cells but did not impair the viability of normal proliferating human lung fibroblast cells. Hoechst 33342 staining and cell cycle analysis performed by flow cytometry demonstrated that the iMDK1 compound induced apoptosis in H441 cells. Furthermore, immunoblot analysis showed that iMDK1 inhibits the PI3 kinase pathway in H441 cells. These results indicate that iMDK1 might be a promising new therapeutic tool for the treatment of Midkine -expressing lung adenocarcinoma with KRAS mutations. Here we show a novel strategy to treat non-small cell lung cancer with Midkine inhibitors.

Citation Format: Takuya Fukazawa, Yutaka Maeda, Huifang Hao, Tomoki Yamatsuji, Munenori Takaoka, Nagio Takigawa, Yoshio Naomoto. Development of novel targeted therapies for non-small cell carcinoma by novel Midkine inhibitors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2180. doi:10.1158/1538-7445.AM2013-2180

Antiproliferative effect of a novel mTOR inhibitor temsirolimus contributes to the prolonged survival of orthotopic esophageal cancer-bearing mice

Esophageal squamous cell carcinoma (ESCC) remains one of the most aggressive cancers with poor prognosis regardless of a several reports that indicate a better therapeutic efficacy using some new chemotherapeutic agents. Recent drug development has contributed to an improved specificity to suppress mTOR activity by which many types of malignancies can be explosively progressed. Temsirolimus (CCI-779, TricelTM) is one of recently synthesized analogs of rapamycin and has provided better outcomes for patients with renal cell carcinoma. In this study, we experimentally evaluated an efficacy of targeting mTOR by temsirolimus for ESCC treatment, with an assessment of its survival advantage using an advanced ESCC animal model. First, we confirmed that the expression of phosphorylated mTOR was increased in 46 of 58 clinical ESCC tumor tissues (79.3%) and appeared to get strengthened with tumor progression. All of ESCC cell lines used in this study revealed an increase of mTOR phosphorylation, accompanied with the upregulation of hypoxia inducible factor-I α (HIF-1α), one of the critical effectors regulated by mTOR. Temsirolimus treatment apparently suppressed the activation of mTOR and its downstream effectors, resulting in the reduced ability of ESCC cell proliferation. Finally, the weekly administration of temsirolimus significantly diminished the size of subcutaneous tumors (vehicle, 3261.6 ± 722.0; temsirolimus, 599.2 ± 122.9; p = 0.007) in nude mice and effectively prolonged orthotopic esophageal cancer-bearing mice (median survival periods: control, 31 d; temsirolimus, 43 d; p = 0.0024). These data suggests that targeting mTOR by temsirolimus may become a therapeutic alternative for esophageal cancer, with a contribution to a better outcome.

Kras(G12D) and Nkx2-1 haploinsufficiency induce mucinous adenocarcinoma of the lung

Mucinous adenocarcinoma of the lung is a subtype of highly invasive pulmonary tumors and is associated with decreased or absent expression of the transcription factor NK2 homeobox 1 (NKX2-1; also known as TTF-1). Here, we show that haploinsufficiency of Nkx2-1 in combination with oncogenic Kras(G12D), but not with oncogenic EGFR(L858R), caused pulmonary tumors in transgenic mice that were phenotypically similar to human mucinous adenocarcinomas. Gene expression patterns distinguished tumor goblet (mucous) cells from nontumorigenic airway and intestinal goblet cells. Expression of NKX2-1 inhibited urethane and oncogenic Kras(G12D)-induced tumorigenesis in vivo. Haploinsufficiency of Nkx2-1 enhanced Kras(G12D)-mediated tumor progression, but reduced EGFR(L858R)-mediated progression. Genome-wide analysis of gene expression demonstrated that a set of genes induced in mucinous tumors was shared with genes induced in a nontumorigenic chronic lung disease, while a distinct subset of genes was specific to mucinous tumors. ChIP with massively parallel DNA sequencing identified a direct association of NKX2-1 with the genes induced in mucinous tumors. NKX2-1 associated with the AP-1 binding element as well as the canonical NKX2-1 binding element. NKX2-1 inhibited both AP-1 activity and tumor colony formation in vitro. These data demonstrate that NKX2-1 functions in a context-dependent manner in lung tumorigenesis and inhibits Kras(G12D)-driven mucinous pulmonary adenocarcinoma.

Anti-tumor effect of a novel FAK inhibitor TAE226 against human oral squamous cell carcinoma

OBJECTIVES

Focal adhesion kinase (FAK) overexpression is frequently found in invasive and metastatic cancers, but its role in oral squamous cell carcinoma is not yet well understood. In order to seek therapies targeting oral squamous cell carcinoma, we developed the novel FAK Tyr(397) inhibitor TAE226 and investigated its anti-tumor effects and mechanisms.

MATERIALS AND METHODS

Expression of phosphorylated FAK Tyr(397) was examined by immunohistochemical and immunoblot analysis. The effect of TAE226 on in vitro and in vivo studies were confirmed by proliferation, cell cycle, apoptosis and angiogenesis analysis.

RESULTS

We found that phosphorylated FAK was highly expressed in human tongue oral squamous cell carcinoma in patients. Importantly, TAE226 greatly suppressed the proliferation, migration and invasion of human oral squamous cell carcinoma SAS cells with an apparent structural change of actin fiber and a loss of cell adhesion. In addition, TAE226 inhibited the expression of phospho-FAK Tyr(397) and phospho AKT Ser(473), resulting in caspase-mediated apoptosis. Furthermore, oral administration of TAE226 in mice suppressed the growth and angiogenesis of oral squamous cell carcinoma xenografts in vivo.

CONCLUSIONS

Our results provide compelling evidence that FAK is critically involved in oral squamous cell carcinoma and that the FAK inhibitor TAE226 can potentially be effectively used for the treatment of oral squamous cell carcinoma.

Esophageal cancer exhibits resistance to a novel IGF-1R inhibitor NVP-AEW541 with maintained RAS-MAPK activity

AIM

To assess the effects of a novel type 1 insulin-like growth factor receptor (IGF-1R) inhibitor, NVP-AEW541, on cell proliferation and signal transduction of esophageal cancer.

MATERIALS AND METHODS

Cell proliferation assay and western blot were conducted to assess the antitumor effects of NVP-AEW541. Genetic modification of RAS by expression vector was applied for overexpression of mutant RAS.

RESULTS

More than 2 μmol/l of NVP-AEW541 was required to effectively inhibit the proliferation of esophageal cancer. NVP-AEW541 potently blocked the activation of IGF-1R and protein kinase B (PKB, also known as AKT), but not of mitogen-activated protein kinase kinase (MEK) and extracellular-signal-regulated kinases (ERK). Active RAS was not reduced by NVP-AEW541 in esophageal cancer cells TE-1, suggesting that insensitivity of esophageal cancer to NVP-AEW541 is due to the maintained RAS-MAPK activity, which did not arise from RAS mutation. Moreover, the transduction of mutant RAS reduced the sensitivity of TE-1 cells to NVP-AEW541.

CONCLUSION

Stimulation of RAS-MAPK pathway is associated with resistance to NVP-AEW541 in esophageal cancer. Combining NVP-AEW541 with inhibitors/antibodies against RAS-MAPK signaling molecules might be more effective for use against esophageal cancer.

Abstract 2771: HSP90 inhibitor NVP-AUY922 exhibits the potent antiproliferative effect in gastrointestinal cancer cells with a lack of PTEN expression

Background: The heat shock protein 90 (HSP90), a molecular chaperone, has provoked great interest as a promising molecular target for cancer treatment, since it is involved in regulating the conformation, stability and functions of key oncogenic proteins. At present, a variety of chemical compounds targeting HSP90 have been developed and have shown convincing anti-neoplastic activity in various preclinical tumor models. Several inhibitors of HSP90 have been reported exhibiting more antitumor efficacy in PTEN-null tumor xenograft. The aim of our study was to evaluate the antitumor effects of a novel HSP90 inhibitor, NVP-AUY922, in human malignant cells, especially in PTEN-null cancer cells. Materials and Methods: Human esophageal cancer (TE-1, TE-4, TE-8, TE-10), gastric cancer (NUGC-3, NUGC-3/IL), pancreatic cancer (PANC-1, MIAPACA-2, Bxpc3) and mutant c-kit-driven lymphocytes (Ba/F3-KE11, Ba/F3-K642, Ba/F3-820Mz), mimicking gastrointestinal stromal tumor cells, were examined. WST assay and/or trypan blue exclusion assay were conducted to assess the anti-proliferation effects of NVP-AUY922 in those cells mentioned above. The activity of cell growth-related molecules such as AKT, ERK, and PTEN were investigated by western blot analysis. Genetic modification using siRNA and expression vector were applied for silencing and overexpression of PTEN, respectively, in cancer cells. Results: Cell viability assays showed that NVP-AUY922 potently inhibits the proliferation of human cancer cell lines, regardless of 5-FU resistance or c-Kit mutation, by which the sensitivity to imatinib can be affected. PTEN-null TE-4 cells exhibited more sensitivity to NVP-AUY922. Interestingly, The sensitivity to NVP-AUY922 was increased by silencing PTEN expression in intact PTEN-expressing TE-10 cells and decreased by exogenous transduction of PTEN in TE-4 cells. Furthermore, NVP-AUY922 significantly inhibited the activity of AKT and ERK in TE-4 cells, but not in TE-10 cells. Conclusion: Inhibition of Hsp90 function by NVP-AUY922 exhibited strong cytotoxicity against most of the cancer cells, including some anticancer drug-resistant cells, revealing its potential for a novel therapeutic alternative to cancer treatment. In addition, this study suggests that the expression status of PTEN determines the sensitivity to HSP90 inhibitor for cancer treatment.

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 2771. doi:1538-7445.AM2012-2771

Abstract 5701: Targeting KRAS lung cancer in vivo by pulmonary surfactant-mediated gene transfer

Pulmonary surfactant has been used as a carrier to deliver a therapeutic virus to dysfunctional lung cells that reside within an intricate lung structure. To investigate whether pulmonary surfactant enhances the efficacy of intratracheal instillation of a therapeutic virus to target KRAS lung cancer in vivo, we developed a recombinant adenovirus that induces cell death only in lung cancer cells and injected the adenovirus into a KRAS lung cancer model mouse intratracheally with or without surfactant. A therapeutic adenovirus that induces cell death only in lung cancer cells was constructed by combining a cancer specific hTERT promoter fused to CEBPα with a modified lung specific CC10 promoter fused to cytotoxic E1A. CEBPα is induced only in cancer cells and activates the CC10 promoter, which in turn induces cytotoxic E1A, and causes cell death only in lung cancer cells in vitro. This adenovirus was intratracheally injected into the KRAS lung cancer model mice (CCSP-rtTA/Tet-op-K-Ras4bG12D bitransgenic mice) in the presence/absence of pulmonary surfactant. Intratracheally-injected therapeutic adenovirus with pulmonary surfactant spread to airways as well as to the alveolar region of the lung and caused reduction of lung tumors developed in the KRAS lung cancer model mouse. The therapeutic adenovirus without pulmonary surfactant spread only to airways and had ten times less effectiveness in tumor reduction. Here, we demonstrate that pulmonary surfactant is an efficient tool to intratracheally deliver a therapeutic virus to treat KRAS lung cancer in vivo.

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 5701. doi:1538-7445.AM2012-5701