bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1316: Molecular features of complete response to neoadjuvant anti-androgen therapy in high risk localized prostate cancer
Authors: Tewari Alok , Cheung Alexander T. , Conway Jake , Park Jihye , Wankowicz Stephanie , Lis Rosina T. , Zhang Zhenwei , AlDubayan Saud , McKay Rana R. , Taplin Mary-Ellen , Van Allen Eliezer M.
Published: September 2020

Though often curable, high-risk localized prostate cancer has a significant chance of recurring either biochemically, locoregionally, or as distant metastatic disease. Efforts are ongoing to evaluate neoadjuvant strategies to reduce this risk of recurrence. Our recent clinical trial showed that intense androgen deprivation with enzalutamide, leuprolide, and abiraterone acetate with prednisone (ELAP) induced pathologic complete response or minimal residual disease (< 5mm) at prostatectomy in 30% of trial patients (exceptional responders). Though previous studies have identified the pathological and genomic heterogeneity of localized prostate cancer, the impact of this heterogeneity on treatment response is unknown. To address this, we performed multi-region whole-exome and whole transcriptome sequencing on tumor and normal prostate regions from 15 exceptional responders and 15 non-responders treated with intensive androgen deprivation prior to prostatectomy. Overall, we found heterogeneous somatic mutation patterns with strong evidence of intra-tumoral heterogeneity and no association between mutation frequency and response. However, when subsetting patients by treatment response, SPOP mutation and SPOPL copy number loss were only observed in exceptional responders, while TP53 mutations were only observed in the non-responders. We observed expression signature differences between exceptional responders and non-responders, with exceptional responders having an increase in Androgen Receptor related gene signatures. Though underpowered to identify statistically significant genomic correlates of response to neoadjuvant ADT, our findings may inform future studies to identify clinically relevant features of high-risk localized prostate cancers to stratify therapies to reduce the risk of disease recurrence.

Citation Format: Alok Tewari, Alexander T. Cheung, Jake Conway, Jihye Park, Stephanie Wankowicz, Rosina T. Lis, Zhenwei Zhang, Saud AlDubayan, Rana R. McKay, Mary-Ellen Taplin, Eliezer M. Van Allen. Molecular features of complete response to neoadjuvant anti-androgen therapy in high risk localized prostate cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1316.
Abstract 1317: RET aberrations in Chinese solid tumor patients: Next-generation sequencing of 10194 patients
Authors: Zhou Chengzhi , Zhang Junhang , Shen Zhuojian , Wang Hongbiao , Li Yun , Wang Minghui , Fu Qin , Zhang Lin , Liu Angen
Published: September 2020

Purpose: RET is an emerging oncogenic target showing promise in phase I/II clinical trials, but the comprehensive genomic landscape of RET aberrations across multiple cancers has had limited exploration.

Experimental Design: We interrogated the molecular portfolio of 10194 patients with diverse cancers for the presence of RET aberrations using targeted next-generation sequencing (NGS) of 450 genes panel (OrigiMed, Shanghai).

Results: Among various cancer types, RET aberrations were identified in 234 cases (2.3%, 234/10 194), with mutations being the most common alteration (62.4%, 146/234), followed by fusions (19.2%, 45/234), amplifications (13.2%, 31/234), and rearrangements (5.1%, 12/234). The proportion of RET mutations in papillary thyroid carcinoma, lung adenocarcinoma, colorectal adenocarcinoma, small cell lung cancer, and other subtypes was 28.6%, 4.2%, 3.6%, 3.0%, and 16.5% respectively. Most patients had coexisting aberrations in addition to RET anomalies (73.5%, 172/234), with the most common being in TP53-associated genes (40.2%, 94/234), the Wnt signaling pathway (39.3%, 92/234), the HR signaling pathway (19.2%, 45/234), the PI3K signaling pathway (17.5%, 41/234), and MAPK effectors (16.2%, 38/234). All 172 patients harboring coexisting aberrations had distinct genomic portfolios.

Conclusions: This study revealed RET aberrations in 2.3% of Chinese solid tumor patients. RET aberrations were detected more in papillary thyroid carcinoma, lung adenocarcinoma, colorectal adenocarcinoma, and small cell lung cancer. Most cases harbored actionable, albeit distinct, coexisting alterations, all of which may potentially contribute to more effective treatment options in the future.

Citation Format: Chengzhi Zhou, Junhang Zhang, Zhuojian Shen, Hongbiao Wang, Yun Li, Minghui Wang, Qin Fu, Lin Zhang, Angen Liu. RET aberrations in Chinese solid tumor patients: Next-generation sequencing of 10194 patients [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 1317.
Abstract 1386: 5-FU-induces PD-L1 in the absence of p53 via ATM dependent activation of STAT3
Authors: Sessler Tamas , Falcone Fiammetta , Gallagher Peter , Wright Timothy , Savage Kienan , Longley Daniel B. , McDade Simon S.
Published: September 2020

Background: 5-Fluorouracil (5-FU) is an antimetabolite DNA damaging chemotherapeutics that forms the backbone for treatment of colorectal cancer (CRC) and currently it is the most commonly used anti-cancer drug. Despite the central role played by p53 in regulating DNA-damage response, its role in regulating response to 5-FU remains unclear.

Methods: To better understand how p53 status differentially affects response to 5-FU, we conducted a detailed phenotypic analysis of the effects of 5FU alone or in combination with Oxaliplatin on cell cycle, DNA damage, cell death, DNA repair and consequent signaling across a panel of p53 isogenic, null and mutant CRC cell lines.

Results: This revealed that while 5-FU induce both p53 dependent and independent cell death, the effects on cell cycle are profoundly different, with p53 deficient cells accumulating in S-phase with prolongated double strand breaks. This is not observed in p53 proficient cells, which are protected from these effects by induction of the p53 target gene p21/CDKN1A limiting cell cycle and enforcing suppression of cell cycle genes. Notably in both p53 or p21 deficient cells 5-FU results in sustained DNA damage-signaling through ATR and ATM in p53 deficient cells which preferentially arrest in S-phase. Importantly, these cells exhibit significant induction of cell surface expression of programmed death ligand-1 (PD-L1), which is enhanced by ATR inhibition concomitant with increased ATM activation. Further analysis indicates that transcriptional induction of PD-L1 is mediated through STAT3 in an interferon independent manner.

Conclusion: This work adds significantly to our understanding of how p53 status impacts 5FU induced cell cycle arrest and response in CRC patients and have important implications for understanding 5-FU response, particularly in future combinations with immune checkpoint inhibitors.

Citation Format: Tamas Sessler, Fiammetta Falcone, Peter Gallagher, Timothy Wright, Kienan Savage, Daniel B. Longley, Simon S. McDade. 5-FU-induces PD-L1 in the absence of p53 via ATM dependent activation of STAT3 [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 1386.
Abstract 1388: Loss of TGFβ signaling increases alternative end-joining and could sensitize high-grade serous ovarian cancer to PARP inhibitors
Authors: Guix Ines , Liu Qi , Palomero Luis , Moore Jade , Pujana Miquel Angel , Barcellos-Hoff Mary Helen
Published: September 2020

Defective DNA damage repair (DDR) is an important therapeutic target in high-grade serous ovarian cancer (HGSOC). This is exemplified by the efficacy of platinum analogues in this disease, as well as the advent of PARP inhibitors that exhibit synthetic lethality when applied to BRCA-mutated tumors. We recently found that loss of transforming growth factor β (TGFβ) signaling in head and neck squamous cell carcinoma causes dysregulation of BRCA1 and hence defective homologous recombination, which pushes cells to rely on error-prone alternative end-joining (alt-EJ) for DDR (Liu et al. Clin Ca Res 2018). To examine this link in ovarian cancer, here we interrogated the transcriptomes from 562 HGSOC patients from The Cancer Genome Atlas Consortium (TCGA) using a 50-gene signature of chronic TGFβ signaling and a 30-gene signature of alt-EJ competency.

Our study unveiled a highly significant (p<0.00001) inverse correlation between TGFβ and alt-EJ in HGSOC. Alt-EJ is error prone, thus we examined the fraction of the genome altered as a function of TGFβ/alt-EJ; the TGFβ/alt-EJ pathway index score was negatively associated with the fraction of genome altered (Pearson correlation coefficient: -0.3288887; P-value = 2.9e-15), with tumors with low TGFβ/high alt-EJ exhibiting more genomic alterations. Alt-EJ increases tumor cell sensitivity to radiation and chemotherapy. Patients with low TGFβ/high alt-EJ profile were associated with an overall survival advantage (p=0.02) and a disease-free survival advantage (p=0.03). Consistent with this, patients with low TGFβ/high alt-EJ profile showed a significantly better response to primary treatment with cisplatin (p=0.038).

These data support combinations of TGFβ inhibitors that could boost response to chemotherapy in HGSOC. Because PARP enzymes are key to alt-EJ, which sensitizes cells to PARP inhibition (ibid), these data suggest a novel means to identify patients that will likely be responsive to PARP inhibitors independently of BRCA mutational status.

Citation Format: Ines Guix, Qi Liu, Luis Palomero, Jade Moore, Miquel Angel Pujana, Mary Helen Barcellos-Hoff. Loss of TGFβ signaling increases alternative end-joining and could sensitize high-grade serous ovarian cancer to PARP inhibitors [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 1388.
Abstract 1407: MicroRNA-18a targeting inhibits the tumor growth of cisplatin-resistant ovarian cancer
Authors: Quiñones-Díaz Blanca Iris , Reyes-González Jeyshka M. , Valiyeva Fatma , Vivas-Mejía Pablo E.
Published: September 2020

Platinum-based therapy remains as the front-line treatment for ovarian cancer. However, despite initial response to treatment, most patients develop platinum resistance and eventually succumb to the malignancy. In an attempt to identify novel targets in cisplatin-resistant ovarian cancer, we studied the role of the microRNA-18a-5p (miR-18a) in cisplatin-resistant ovarian cancer. miR-18a is part of the vastly researched miR-17-92 cluster. Although most members of this cluster have been associated with pro-tumorigenic roles in several cancers, recent findings suggest that miR-18a plays a tumor-suppressive role in ovarian cancer. However, the specific role of miR-18a in platinum resistance has yet to be elucidated. In this study, Real-Time PCR analysis was performed to measure the levels of miR-18a in several ovarian cancer cell lines. We found miR-18a downregulation in cisplatin-resistant ovarian cancer cells relative to their sensitive counterparts. Therefore, we assessed the effect of miR-18a upregulation by oligonucleotide microRNA mimics (OMM) in tumor growth using a xenograft mouse model of cisplatin-resistant ovarian cancer. As ovarian tumors have been shown to overexpress the Folate Receptor α (FRα), we used nanoliposomes conjugated to folic acid as vehicles to deliver the OMMs. Following intraperitoneal injections of OMM-loaded liposomes (twice per week for three weeks), there was a significant decrease in tumor weight of miR-18a-OMM treated mice in comparison to the control-OMM group. Moreover, immunohistochemical analysis was performed on the mice tumor tissues to assess the levels of cell proliferation and angiogenesis markers (ki67 and CD31, respectively). Our study suggests that miR-18a halts cisplatin-resistant ovarian cancer tumor progression.

This work was supported by the RCMI grant: U54 MD007600, UPR Comprehensive Cancer Center and NIGMS-RISE R25-GM061838.

Citation Format: Blanca Iris Quiñones-Díaz, Jeyshka M. Reyes-González, Fatma Valiyeva, Pablo E. Vivas-Mejía. MicroRNA-18a targeting inhibits the tumor growth of cisplatin-resistant ovarian cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1407.
Abstract 1442: Identifying the molecular basis by which βIII-tubulin promotes tumor cell survival and drug resistance in non-small cell lung cancer
Authors: Brayford Simon , Teo Wee Siang , Parker Amelia , McVeigh Laura , McCarroll Joshua A. , Kavallaris Maria
Published: September 2020

Lung cancer is the leading cause of cancer-related mortality worldwide with the most common sub-type, non-small cell lung carcinoma (NSCLC), accounting for >80% of cases. Despite advances in treatments, 5-year survival rates for this disease remain dismal. Advanced NSCLC responds poorly to current therapy and the mechanisms underlying its resistance and aggressive nature are not well defined. Microtubules form a component of the cell cytoskeleton and alterations in the expression of microtubule proteins are increasingly correlated with more aggressive and treatment-refractory cancers. βIII-tubulin is a neuronal-specific isotype that is aberrantly expressed in a range of cancers including NSCLC, and has been found to be correlated with reduced patient survival.

Our group has recently demonstrated that βIII-tubulin contributes to activation of the PI3K/AKT cell-survival pathway in NSCLC cells[1]. One of the key negative regulators of this pathway is the tumor suppressor PTEN. PTEN can inhibit cell growth, migration and invasion, and a loss of PTEN function is often associated with cancer progression through AKT hyperactivation.

Here, using forced-genetics cell models, we show that AKT activation is reduced by βIII-tubulin knockdown, and that re-expression of βIII-tubulin restores these levels in NSCLC cells. Interestingly, we also found that βIII-tubulin knockdown resulted in increased PTEN mRNA along with altered levels of Snail-1/β-catenin, suggesting a possible role for βIII-tubulin in regulating the transcriptional pathway of the PTEN tumor suppressor. Building on these findings, we also identified, through a high-throughput cell-based drug screen, several receptor tyrosine kinase inhibitors that synergize with βIII-tubulin knockdown to reduce NSCLC cell proliferation and tumoroid growth.

Together, our data demonstrate an important role for βIII-tubulin in modulating the activation and/or expression levels of signaling proteins which form part of a major pro-survival pathway in NSCLC. In addition, our results suggest that inhibition of βIII-tubulin in combination with drugs that target multiple kinases may offer a novel therapeutic strategy for the treatment of NSCLC to improve patient outcomes.

[1] McCarroll et al., TUBB3/betaIII-tubulin acts through the PTEN/AKT signaling axis to promote tumorigenesis and anoikis resistance in non-small cell lung cancer. Cancer Research. 2015;75:415-425.

Citation Format: Simon Brayford, Wee Siang Teo, Amelia Parker, Laura McVeigh, Joshua A. McCarroll, Maria Kavallaris. Identifying the molecular basis by which βIII-tubulin promotes tumor cell survival and drug resistance in non-small cell lung cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1442.
Abstract 1443: Inhibiting HMG-CoA reductase suppresses non-small cell lung carcinogenesis
Authors: Wang Qiushi , Zhang Tianshun , Bai Ruihua , Wang Keke , Li Xiang , Liu Kangdong , Wang Ting , Chang Xiaoyu , Ma Weiya , Bode Ann , Xia Qingxin , Song Yongping , Dong Zigang
Published: September 2020

3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (HMGCR) is a rate-limiting enzyme in the mevalonate pathway and is associated with the development of several tumor types. However, the role of HMGCR in non-small cell lung cancer (NSCLC) is still unknown. In the present study, we found that HMGCR is overexpressed in human lung adenocarcinoma tissues compared with normal tissues. Knockdown of HMGCR in NSCLC cells attenuated growth and induced apoptosis in vitro and in vivo. Furthermore, we found that fluvastatin, an inhibitor of HMGCR, suppressed NSCLC cell growth and induced apoptosis. Intriguingly, fluvastastin functions by inhibiting the HMGCR-driven Braf/MEK/ERK1/2 and Akt signaling pathways. Notably, fluvastatin attenuated tumor growth in 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis and in a patient-derived xenograft (PDX) lung tumor model. Overall, our findings suggest that fluvastatin might be promising chemopreventive or potential therapeutic drug against NSCLC tumorigenesis, providing hope for rapid clinical translation.

Citation Format: Qiushi Wang, Tianshun Zhang, Ruihua Bai, Keke Wang, Xiang Li, Kangdong Liu, Ting Wang, Xiaoyu Chang, Weiya Ma, Ann Bode, Qingxin Xia, Yongping Song, Zigang Dong. Inhibiting HMG-CoA reductase suppresses non-small cell lung carcinogenesis [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 1443.
Abstract 1447: Elucidating the mechanism of Dock7-mediated cellular transformation
Authors: Pumar Oriana Y. Teran , Wilson Kristin F. , Cerione Richard A.
Published: September 2020

Akt is a serine/threonine protein kinase that receives signals from a plethora of external and internal stimuli in order to promote survival and regulate cellular growth and metabolism. Akt is part of the highly conserved PI3K/Akt signaling axis and is classically regulated by its interaction with the phosphoinositide, PIP3, and its subsequent phosphorylation at S473 and S308 by the mTOR complex 2 (mTORC2) and 3-Phosphoinositide-dependent protein kinase 1 (PDK1), respectively. Altered Akt activity has been linked to numerous diseases, such as cancer, diabetes and neurodegenerative diseases. Specifically, PI3K/Akt deregulation occurs in approximately one third of human cancers and ~40% of breast cancers.

My research focuses on Dock7, a Guanine Nucleotide Exchange Factor (GEF) for the small GTPases Cdc42 and Rac1, and a novel player in the regulation of Akt activity and stability. Dock7 belongs to the Dock family of atypical GEFs and contains two evolutionarily conserved domains, DHR1 (a putative lipid binding domain) and DHR2 (the catalytic GEF domain). The expression level of Dock7 correlates with an unfavorable prognosis in liver cancer patients, and it is highly expressed in triple-negative breast cancers. Studies in our laboratory showed Dock7 is essential for the transformed properties of several cancer cell lines, and that it interacts with Akt in co-immunoprecipitation assays. In order to decipher the mechanism by which Dock7 mediates transformation, I created a Crispr-Cas9 Dock7 Knock-out HeLa cell line. I proceeded to confirm that these cells are not able to grow in an anchorage independent manner nor in serum free conditions, two hallmarks of transformation. Furthermore, in comparison to the phosphorylation status of Akt in parental HeLa cells, I found that in Dock7 KO HeLa cells, Akt is not phosphorylated at the S473 site in the absence of growth factors, indicative of lower basal activity. Accordingly, phosphorylation of downstream effectors of Akt is also downregulated. Besides promoting the phosphorylation state of Akt, Dock7 plays a role in the stability of the Akt protein during certain cellular stresses, highlighting a versatile and important role for Dock7 in Akt regulation and a potential target for therapeutic intervention in tumors where Akt is deregulated.

Citation Format: Oriana Y. Teran Pumar, Kristin F. Wilson, Richard A. Cerione. Elucidating the mechanism of Dock7-mediated cellular transformation [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 1447.
Abstract 1449: The molecular dissection of pro-tumorigenic activity of mesothelin in pancreatic cancer
Authors: Joseph Sarah Mary , Avula Leela Rani , Zhang Xianyu , Alewine Christine Campo
Published: September 2020

Mesothelin (MSLN) is a cancer-specific antigen that is differentially expressed in many human cancers, including malignant mesothelioma and pancreatic, ovarian, and lung adenocarcinomas. The MSLN gene encodes a 71 kD precursor protein, that is reportedly cleaved by the intracellular protease furin to produce a 31 kD N-terminal fragment called megakaryocyte potentiating factor (MPF) and mature 40 kD MSLN C-terminal fragment. Mature MSLN is localized to the cell surface by a GPI-linkage. We synthesized a series of mutant MSLN constructs containing sequence modifications predicted to disrupt the canonical signaling sequences for furin cleavage and GPI-linkage. These constructs were then expressed in a MSLN knock-out pancreatic cancer cell line. We used flow cytometry to detect cell surface MSLN expression and immunoblotting for MSLN proteins to assess the effect of mutation. We expected that a 23aa C-terminal truncation that removed a predicted hydrophobic signaling sequence for GPI-linkage would eliminate plasma membrane insertion of MSLN. However, this truncation did not suppress cell surface expression. A deeper 31aa truncation which eliminated two potential anchoring sites at Ser599 and Ser606 was required to successfully eliminate surface expression. We are currently evaluating the growth of this pancreatic cancer cell line expressing GPI-truncated soluble MSLN in vitro and in vivo. Our results suggest that MSLN may have an alternate means for membrane insertion besides GPI-linkage. For the panel of furin site mutants, non-conservative mutations were made to disrupt the reported consensus recognition motif for furin 290-RPRFRR-295 (R290H, R292Q, RR294-5GG) or the entire motif region was deleted (289_315del). Mutants were also made to disrupt the putative furin cleavage site (R286A) and neighboring basic residues that were potential protease cleavage sites (R282A, K306Q, K307Q). These furin site mutants were expected to eliminate cleavage of the 71 kD precursor protein to 40 kD mature MSLN. We found that all mutants did increase levels of precursor but did not ablate formation of mature MSLN. Similarly, expression of WT full-length MSLN into the LoVo cell line, which lacks furin activity, still resulted in formation of 40 kD mature MSLN predominately. In conclusion, we found that precursor processing to mature MSLN still took place despite extensive mutation of the putative furin cleavage site and in the absence of active furin. These results suggest that additional proteases besides furin can perform MSLN precursor cleavage.

Citation Format: Sarah Mary Joseph, Leela Rani Avula, Xianyu Zhang, Christine Campo Alewine. The molecular dissection of pro-tumorigenic activity of mesothelin in pancreatic cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1449.
Abstract 1459: Selective killing of SMARCA4-deficient gynecologic cancers by mitochondria oxidative phosphorylation inhibitors
Authors: Wang Yemin , Ong Dionzie , Chen Shary Yuting , Li Eunice , Orlando Krystal , Raupach Elizabeth , Ji Jennifer , Weissman Bernard , Pirrotte Patrick , Humtsman David
Published: September 2020

Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT) and dedifferentiated carcinoma of the ovary or endometrium are rare but highly aggressive types of gynecologic cancers. We and others have recently demonstrated that genetic inactivation of SMARCA4, one of the two ATPases of the SWI/SNF chromatin remodeling complex, along with protein loss is the only recurrent somatic mutation of SCCOHT. Furthermore, SMARCA4 loss appears as a key event in the development of a subset of dedifferentiated carcinoma of the ovary, endometrium or other organs. These SMARCA4-deficient dedifferentiated tumors and SCCOHT usually lose the expression of SMARCA2, the alternative ATPase of the SWI/SNF complex. Through mining the publicly available genome-wide CRISPR screen database from the Broad Institute DepMap Project for about 500 cell lines, we identified that SMARCA4/A2-dual deficient ovarian cell lines are selectively sensitive to the genetic ablation of multiple components of mitochondria electron transfer chain (ETC). Using seahorse metabolism assays, we revealed that SCCOHT cells have reduced glycolysis in comparison to other ovarian cancer cells and utilize mitochondria respiration for energy production regardless of the availability of glucose. Accordingly, both SCCOHT and SMARCA4-deficient dedifferentiated ovarian carcinoma cell lines are remarkably more sensitive to several inhibitors of ETC complex I, and tigecycline, a selective inhibitor of the mitochondria ribosomal translation, than other ovarian cancer cells, such as SMARCA4-intact ovarian high-grade serous carcinoma cells and clear cell ovarian carcinoma cells regardless of the expression level of ARID1A, a SWI/SNF complex subunit frequently lost in clear cell ovarian carcinoma. Re-expression of SMARCA4 increased the expression of SLC2A1, encoding the glucose transporter GLUT1, and decreased the sensitivity of SCCOHT cells to ETC complex I inhibitors, suggesting that SMARCA4 loss may reduce the transport of glucose leading to reduced glycolysis and increased reliance on mitochondria respiration, which is currently under investigation. Therefore, our data suggest that selective targeting mitochondria respiratory complex function can be an effective strategy for SCCOHT and other SMARCA4-deficient dedifferentiated cancers of gynecologic tract or other organs.

Citation Format: Yemin Wang, Dionzie Ong, Shary Yuting Chen, Eunice Li, Krystal Orlando, Elizabeth Raupach, Jennifer Ji, Bernard Weissman, Patrick Pirrotte, David Humtsman. Selective killing of SMARCA4-deficient gynecologic cancers by mitochondria oxidative phosphorylation inhibitors [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 1459.
Abstract 1485: E7011, a novel anti-angiogenesis inhibitor targeting Notch4 receptor signal pathway
Authors: Adachi Yusuke , Sakamoto Yoshimasa , Nakazawa Youya , Tachino Sho , Ito Ken , Abe Takanori , Minoshima Yukinori , Hoshino-Negishi Kana , Ogasawara Hideaki , Kawakatsu Tomomi , Nishimura Miyuki , Shimizu Masashi , Tahara Kazuhiro , Sato Toshitaka , Suzuki Katsuhisa , Agarwala Kishan , Iwata Masao , Funahashi Yasuhiro , Nomoto Kenichi , Ozawa Yoichi , Matsui Junji , Imai Toshio , Kato Yu
Published: September 2020

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.
Abstract 1486: Exosomal miR-141 promoted tumor angiogenesis via KLF12 in small cell lung cancer
Authors: Mao Shuangshuang , Lu Zhiliang , Zheng Sufei , Zhang Guochao , Huang Jianbing , Sun Nan , He Jie
Published: September 2020

Background: Angiogenesis, the basic requirement for the survival of tumor cells, has been considered to be one of the malignant characteristics of small cell lung cancer (SCLC) and was closely related to the poor outcomes of SCLC patients. MiR-141 has been found to play a pro- or anti-angiogenetic role in different cancers while its role in SCLC angiogenesis has never been explored.

Methods: We isolate total RNA from plasm exosomes and serum samples from two cohorts of SCLC patients respectively to detect the expression of circulating miR-141 in SCLC patients using qRT-PCR. miR-141 was overexpressed in SCLC cell-secreted exosomes to investigate its effects on cell migration, tube formation and microvessel sprouting capabilities of human umbilical vein vascular endothelial cells (HUVECs) both in vitro and in vivo. A dual-luciferase assay was conducted to validate the direct target gene of miR-141.

Results: We showed that the level of circulating miR-141 was significantly upregulated in a total of 116 SCLC patients compared with normal volunteers, and the increased miR-141 was revealed to be associated with advanced patient TNM stages which implying the potential oncogenic role of miR-141 in SCLC malignances. In vitro experiments indicated that miR-141 was packaged into SCLC cell-secreted exosomes and was delivered to HUVECs via exosomes to strengthen the migration, invasion, tube formation and microvessel sprouting capabilities of HUVECs. Moreover, mouse models demonstrated that exosomal miR-141 derived from SCLC cells induced neo-angiogenesis in vivo and subcutaneous tumor nodules developed from SCLC cells with miR-141 overexpression showed higher microvessel densities and faster tumor growth than which developed from negative control cells. Combining miRNA target prediction tools with a dual-luciferase assay, we identified that KLF12 was the direct target gene of miR-141 and the angiogenetic promotion effect of miR-141 on HUVECs was abrogated by overexpressing KLF12.

Conclusions: Our results elaborated the specific function of exosomal miR-141/KLF12 pathway in SCLC angiogenesis for the first time and provided potential novel targets for anti-angiogenetic therapies in SCLC patients. Our study highlighted the critical role of exosomal miRNAs in SCLC microenvironments and cell communications which offered novel clues for the future exploration of molecular mechanisms of SCLC malignances.

Citation Format: Shuangshuang Mao, Zhiliang Lu, Sufei Zheng, Guochao Zhang, Jianbing Huang, Nan Sun, Jie He. Exosomal miR-141 promoted tumor angiogenesis via KLF12 in small cell lung cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1486.
Abstract 1511: A highly plastic cell state emerges during lung adenocarcinoma evolution
Authors: Chan Jason Earl , Marjanovic Nemanja Despot , Hofree Matan , Canner David , Wu Katherine , Hartmann Griffin , Smith Olivia C. , Kim Jonathan , Hudson Anna , Subramanian Ayshwarya , Pitter Kenneth , Rekhtman Natasha , Massion Pierre P. , Poirier John T. , Rudin Charles M. , Jacks Tyler , Regev Aviv , Tammela Tuomas
Published: September 2020

The role of tumor heterogeneity in the progression of lung adenocarcinoma remains poorly understood. In order to understand how tumor heterogeneity impacts tumor evolution, we profiled single cell transcriptomes from genetically engineered mouse lung tumors at various stages. We observed a set of reproducible transcriptional states whose diversity increased over time. Additionally, we identified a highly plastic cell state that arose in every tumor we obtained. We profiled this cell state and identified a robust potential for phenotypic switching, an increased potential for spheroid formation in tumor sphere cultures, and an enrichment of the highly plastic cell state after chemotherapeutic stress in vivo. Our work suggests that the highly plastic cell state plays a significant role, and perhaps even drives, tumor progression and resistance to therapy in lung adenocarcinoma.

Citation Format: Jason Earl Chan, Nemanja Despot Marjanovic, Matan Hofree, David Canner, Katherine Wu, Griffin Hartmann, Olivia C. Smith, Jonathan Kim, Anna Hudson, Ayshwarya Subramanian, Kenneth Pitter, Natasha Rekhtman, Pierre P. Massion, John T. Poirier, Charles M. Rudin, Tyler Jacks, Aviv Regev, Tuomas Tammela. A highly plastic cell state emerges during lung adenocarcinoma evolution [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 1511.
Abstract 1572: Single cell sequencing reveals the microenvironment network in multifocal pulmonary nodules
Authors: Liu Dongcheng , Pan Pan , Li Shixuan , Cheng Zhiqiang , Wang Guangsuo , Zou Chang
Published: September 2020

Tumor microenvironment plays an important role in tumorigenesis in cancer development, however, little is known about its heterogeneity and evolution progression during early stage of lung cancer. In this study, single cell sequencing was applied to uncover the transcriptome in the microenvironment and the complex ecosystem of stromal cells in pulmonary nodules including atypical adenomatous hyperplasia (AAH) adenocarcinoma in situ (AIS), invasive adenocarcinoma (MIA) and invasive adenocarcinoma (IA). Although the expression or mutation of driver genes were detected in different stage of pulmonary lesion tissues that might contribute to the development of lung cancer, tumor environment including immune system are found to be important for the progression of tumorigeneses. This study provided evidence that the different evolutionary selection and microenvironment network in multifocal pulmonary nodules in the same individual resulted in various cancer progression stages. To our knowledge, this study first provides an overview of the genetic basis and tumor environment of human lung nodule by single-cell sequencing.

Keywords: Single cell sequencing; heterogeneous; microenvironment; multifocal pulmonary nodules

Citation Format: Dongcheng Liu, Pan Pan, Shixuan Li, Zhiqiang Cheng, Guangsuo Wang, Chang Zou. Single cell sequencing reveals the microenvironment network in multifocal pulmonary nodules [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 1572.
Abstract 1577: Gene expression studies using microgel embedded pancreatic cancer spheroids
Authors: Prasad Saumya , Chandra Anil , Lonardo Enza , Parasido Erika , Albanese Christopher , Mercato Loretta L. del
Published: September 2020

Pancreatic ductal adenocarcinoma (PDAC) is known to be one of the deadliest cancers due to its late diagnosis and faster metastasis rate1. Thus, the time required to test the patient-derived cancer cells against different therapeutics becomes extremely crucial. Gene expression analysis using real-time PCR is vital, typically when designing patient-specific therapeutics. 2D tumor models do not represent the true picture of the tumor in vivo. In order to perform these gene expression studies, robust 3D cancer models are required2. The traditional techniques of generating cancer spheroids using U-bottom wells and hanging drop methods are effective but are limited by scalability as well as the limitations associated with the traditional organoid architecture. Gene expression studies of spheroids under different combinations of drug treatment thus requires many well defined and easy to handle spheroids. Here, we are trying to perform real-time PCR studies to access the gene expression changes on MIA PaCa-2 microgel based spheroids generated using co-axial droplet microfluidics with or without stromal cells. This 3D platform will enable gene expression studies in miniature co-culture tumor models. In addition, PCR and single-cell sequencing analyses will define the gene expression changes in the recently described conditionally reprogramed, patient-derived, primary PDAC cultures3. The establishment and analysis of this 3D model is fast, reproducible and can be easily scaled to enable high-throughput screening, thereby providing an opportunity to design patient-specific precision medicine.

The research leading to these results received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 759959, ERC-StG “INTERCELLMED”).

References:

(1) Adamska, A.; Domenichini, A.; Falasca, M. Pancreatic Ductal Adenocarcinoma: Current and Evolving Therapies. Int. J. Mol. Sci. 2017, 18 (7).

(2) Moreira, L.; Bakir, B.; Chatterji, P.; Dantes, Z.; Reichert, M.; Rustgi, A. K. Pancreas 3D Organoids: Current and Future Aspects as a Research Platform for Personalized Medicine in Pancreatic Cancer. Cell. Mol. Gastroenterol. Hepatol. 2018, 5 (3), 289-298.

(3) Parasido, E.; Avetian, G. S.; Naeem, A.; Graham, G.; Pishvaian, M.; Glasgow, E.; Mudambi, S.; Lee, Y.; Ihemelandu, C.; Choudhry, M.; et al. The Sustained Induction of C-MYC Drives Nab-Paclitaxel Resistance in Primary Pancreatic Ductal Carcinoma Cells. Mol. Cancer Res. 2019, 17 (9), 1815-1827.

Citation Format: Saumya Prasad, Anil Chandra, Enza Lonardo, Erika Parasido, Christopher Albanese, Loretta L. del Mercato. Gene expression studies using microgel embedded pancreatic cancer spheroids [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 1577.
Abstract 1580: Distinct pathways of lytic and blastic bone metastases in prostate cancer patients
Authors: Ihle Claire L. , Provera Meredith D. , Straign Desiree M. , Smith E. Erin , Edgerton Susan M. , Van Bokhoven Adrie , Lucia M. Scott , Owens Philip
Published: September 2020

The most common metastatic lesions of prostate cancer are in the bone and can be classified into three distinct pathologic subtypes: lytic, blastic, and an indeterminate mixture of both. There is no immunotherapy guidance for treating patients based on lytic or blastic tumor induced bone disease. To identify distinct tumor and stroma in lytic and blastic prostate cancer bone metastases, we investigated a cohort of decalcified formalin-fixed and paraffin-embedded (FFPE) patient bone biopsy specimens that contained metastatic prostate cancer with lytic or blastic features. Tissue sections were utilized for immunohistochemistry (IHC) staining, isolation of RNA for gene expression, and Digital Spatial Profiling (DSP) of changes in both the tumor and microenvironment. A diverse set of unique immune cell populations and signaling pathways to both lytic and blastic types of prostate cancer metastases were present. High proportions of macrophages were present in lytic tumor induced bone disease, and T cells were present in lytic and blastic samples. In blastic lesions, immune cells were enriched for pSTAT3 and components of the JAK-STAT pathway. In lytic lesions, immune cells exhibited enhanced pAKT activity and components of the PI3K-AKT pathway. Expression of key immune checkpoint targets were identified in blastic prostate cancer, providing new therapeutic targets for patients with bone metastases. To further investigate which individual cells comprising the stroma and tumor have active JAK-STAT signaling, we performed fluorescent multiplex-IHC (mIHC). A tumor and myeloid panel of antibodies was used to identify on a single cell resolution which specific cell types are enriched for pSTAT3 in the tumor microenvironment. The identification of pAKT or pSTAT3 as promising therapeutic targets could be rationally employed to individual patients. The presence of macrophages and T cells in samples suggest that conventionally “cold” prostate cancer bone metastases warrant reappraisal as capable immunotherapy responders. Biopsies could guide selection of patients into appropriate therapeutic interventions based on protein levels and RNA expression of desired targets in metastatic disease.

Citation Format: Claire L. Ihle, Meredith D. Provera, Desiree M. Straign, E. Erin Smith, Susan M. Edgerton, Adrie Van Bokhoven, M. Scott Lucia, Philip Owens. Distinct pathways of lytic and blastic bone metastases in prostate cancer patients [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 1580.
Abstract 1591: Single cell analysis of uveal melanoma reveals new evolutionary complexity
Authors: Durante Michael A. , Rodriguez Daniel A. , Kurtenbach Stefan , Kuznetsoff Jeffim N. , Sanchez Margaret I. , Decatur Christina L. , Snyder Helen , Feun Lynn G. , Livingstone Alan S. , Harbour J. William
Published: September 2020

Uveal melanoma (UM) is a highly metastatic cancer that is largely unresponsive to molecular and immune therapy. We used scRNA-seq and other methods to analyze 59,915 tumor and non-neoplastic cells from 8 primary and 3 metastatic UMs. This analysis confirmed the class 1/class 2 transcriptomic landscape established from bulk analysis and revealed newly identified subclonal genomic complexity and transcriptional states consistent with phenotype plasticity. The immune compartment comprised a previously unappreciated diversity of cell types. There was low expression of CTLA4 and PD1, but strong expression of a different checkpoint molecule. These findings revealed a dynamic ecosystem in which UM and immune cells co-evolve along trajectories associated with specific genomic aberrations, and they may explain the poor response of UM to current immunotherapy regimens. We identified a new promising candidate for immune checkpoint blockade in metastatic UM.

Citation Format: Michael A. Durante, Daniel A. Rodriguez, Stefan Kurtenbach, Jeffim N. Kuznetsoff, Margaret I. Sanchez, Christina L. Decatur, Helen Snyder, Lynn G. Feun, Alan S. Livingstone, J. William Harbour. Single cell analysis of uveal melanoma reveals new evolutionary complexity [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 1591.
Abstract 1617: Developing new mouse models of metastatic lung cancer
Authors: Wells Julie , Maser Richard S. , McGee Teresa , Memishian Wendy , Doty Rosalinda , Bult Carol J.
Published: September 2020

INTRODUCTION: The focus of this work is to develop new mouse models for metastatic lung cancer. Lung cancer is the leading cause of cancer deaths worldwide and greater than 90% of human cancer deaths are due to metastasis. Metastatic disease in most existing mouse models of lung cancer is typically sporadic and often requires aging mice for several months. These factors limit the usefulness of mouse models for basic and pre-clinical research aimed at effective treatment of metastatic disease.

METHODS AND RESULTS: We have developed a new mouse model of lung cancer and are in the process of developing two additional models. In the first model, we added mutations in Dicer1, an RNAse III enzyme within the microRNA (miRNA) biosynthesis pathway to a mouse model of Kras-driven pulmonary adenocarcinoma. When we combined conditional expression of an oncogenic allele of Kras (KrasG12D), deletion of both alleles of Trp53 and one allele of Dicer1 in Club cells with expression of truncated Dicer1 in alveolar type II cells, we generated mice with metastatic pulmonary adenocarcinoma. In 30% of these mice, metastatic tumors were observed in the lymph nodes within 11 weeks of tumor induction. In a second mouse model, we switched the cell types expressing the various mutations to determine the effects of cell of origin on tumor progression and metastasis. Our preliminary results suggest that adenocarcinoma develops even faster when KrasG12D is expressed and Trp53 and one allele of Dicer1 are deleted in alveolar type II cells. Finally, based on an analysis of human lung cancer genomics data from TCGA, we generated a mouse model with mutations in Zfhx4 and are crossing these mice with our models that express oncogenic KrasG12D, delete expression of Trp53 and one allele of Dicer1 and truncate the second allele of Dicer1 to determine the effects of adding Zfhx4 mutations on progression and metastasis of pulmonary adenocarcinoma.

CONCLUSIONS: Through cell type specific truncation/deletion of Dicer1 we have generated new mouse models that rapidly develop pulmonary adenocarcinomas and metastatic disease. These models have potential for both understanding the basic processes of metastasis and for pre-clinical studies aimed at preventing and/or treating metastatic lung cancer.

Citation Format: Julie Wells, Richard S. Maser, Teresa McGee, Wendy Memishian, Rosalinda Doty, Carol J. Bult. Developing new mouse models of metastatic lung cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1617.