bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1770: Ectopic expression of ULBP2 promotes tumor progression in syngeneic mice
Authors: Yamaguchi Kosuke , Miyake Naomi , Teruya Yasuhiko , Yamane Kohei , Kinoshita Naoki , Sakamoto Tomohiro , Kodani Masahiro , Chikumi Hiroki , Yamasaki Akira 
Published: July 2021

Abstract
ULBP2 is one of the ligands for NKG2D (NKG2DLs). ULBP2 expression is induced in transformed cells and is recognized by immune effector cells via the activating NKG2D immunoreceptor. Previously, we reported high concentrations of serum-soluble ULBP2 (sULBP2) were correlated with poor prognosis in NSCLC patients. As a possible mechanism, we demonstrated that sULBP2 directly suppressed the cytolytic activity of peripheral blood mononuclear cells (PBMCs). However, little is known about the in vivo function of human NKG2DLs on tumor cells. The present study investigates the function of human NKG2DLs in the syngeneic C57BL/6 mice. We generated ULBP2 stably expressing B16 melanoma cell lines (ULBP2-B16). As previously reported, 4-hour 51Cr releasing assay showed NK cell cytotoxicity against the tumor cells was enhanced by ectopic expression of ULBP2 on the tumor cells. IFN-gamma production in NK cells was decreased by non-contact co-culture with ULBP2-B16. To investigate the in vivo function of ULBP2, C57BL/6 mice were inoculated s.c. with mock-B16 cells or ULBP2-B16 cells. ULBP2-B16 tumors grew rapidly compared to mock-B16 tumors. NKG2D blockade by anti-NKG2D antibody injected i.p. suppressed tumor growth of ULBP2-B16 tumors. Spleen cells and tumor-infiltrating lymphocytes (TILs) were analyzed by flow cytometry. NKG2D was expressed on splenic NK cells, while it was rarely expressed on splenic CD8+ T cells. NKG2D was downregulated on NK cells in TILs (NK-TILs) from ULBP2-B16. NKG2D was highly expressed on CD8+ T cells in TILs (CD8+-TILs) from mock-B16 tumors, while its expression was suppressed on these from ULBP2-B16 tumors. Degranulation analysis revealed that ULBP2-B16 reduced activity of NK-TILs and CD8+-TILs compared to mock-B16. In conclusion, ectopic expression of ULBP2 on tumor cells promotes tumor progression via suppression of the activity of NK cells and CD8+ T cells. These findings suggest that neutralization of NKG2DLs may be a promising approach for the treatment of NKG2DLs-expressing tumors.
Citation Format: Kosuke Yamaguchi, Naomi Miyake, Yasuhiko Teruya, Kohei Yamane, Naoki Kinoshita, Tomohiro Sakamoto, Masahiro Kodani, Hiroki Chikumi, Akira Yamasaki. Ectopic expression of ULBP2 promotes tumor progression in syngeneic mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1770.
Abstract 1771: SIGLEC15 humanized knock-in mice are a powerful tool to evaluate new therapies for cancer and osteoporosis
Authors: Li Huilin , Zhao Lei , Tian Maopeng , Chromikova Veronika , Yu Zhaoxue (Luke) 
Published: July 2021

Abstract
SIGLEC15 (Sialic acid-binding immunoglobulin-like lectin 15) belongs to the Siglec family of sialic acid-binding, immunoglobulin-like proteins. SIGLEC15 is an effective immunosuppressive molecule which is highly expressed on M2 macrophages but can be upregulated in many human cancers. The SIGLEC15 signaling pathway is non-redundant to the PD-L1 pathway in cancer, and the surface expression of SIGLEC15 is generally non-overlapping with PD-L1 expression on tumors. SIGLEC15 engages a putative responder protein expressed on the surface of effector cells, such as CD8 T cells, inducing suppression of anti-tumor immune responses. Blocking of SIGLEC15 amplifies anti-tumor immunity in the tumor microenvironment and inhibits tumor growth. This opens a road for anti-SIGLEC15 antibody therapeutics which may provide a solution for patients with SIGLEC15-positive and PD-L1-negative tumors, a patient population less likely to respond to a PD-1/PD-L1 directed therapy. Biocytogen has generated a humanized SIGLEC15 mouse model to address the need for in vitro functional validation and in vivo efficacy evaluation of SIGLEC15-targeting strategies. In these mice, genomic DNA spanning exons 2~4 of mouse Siglec15 gene encoding the extracellular domain, was replaced by its human counterpart. Following the humanization procedure, human SIGLEC15 could be detected on bone marrow derived macrophages (BMDM). Basal leukocyte subpopulations, including T/B/NK cells, DC, granulocytes, and monocytes/macrophages, were similar between humanized and wild-type mice. In addition, Biocytogen has generated a humanized MC38 cell line, in which the mouse Siglec15 gene was replaced with the full-length human coding sequence. The successful humanization of M38 was confirmed by RT-PCR and flow cytometry. Using the hMC38 tumor model, we showed robust efficacy of the anti-SIGLEC15 antibodies in inhibiting tumor growth in vivo. Combined SIGLEC15 and PD-1/PD-L1 blockade showed greater tumor inhibition than monotherapies. In summary, SIGLEC15 humanized mice can be employed for in vivo efficacy evaluation of anti-SIGLEC15 antibodies in immune normalization approaches for cancer treatment. Besides the tumor models (B16F10 and other tumors underway), we are also actively exploring the feasibility of the SIGLEC15 humanized mice as a pre-clinical model for osteoporosis in a light of recent discovery of SIGLEC15's role in osteoclast differentiation.
Citation Format: Huilin Li, Lei Zhao, Maopeng Tian, Veronika Chromikova, Zhaoxue (Luke) Yu. SIGLEC15 humanized knock-in mice are a powerful tool to evaluate new therapies for cancer and osteoporosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1771.
Abstract 178: Desmosome mutations in melanoma promote cellular proliferation and disease progression
Authors: Baron Maayan , Ideker Trey 
Published: July 2021

Abstract
Desmosomes are transmembrane protein complexes that contribute to cell-cell adhesion in the epithelia and other tissues under mechanical stress. Aberrant desmosome expression is often associated with developmental diseases leading to impaired tissue integrity. Recently, similar findings have been reported in cancer; Mutations in desmosomes genes have been observed in various cancer types including skin cancer, head and neck and lung cancer, however mostly epigenetic alterations have been used to associate desmosomes as suppressors of tumor metastasis. Here, we report that desmosomes are frequently mutated in seven cancer types. In melanoma, we find that over 70% of tumors have non-synonymous mutations in desmosomes, and that the desmosome mutational burden is associated with a strong decrease in mRNA expression levels in primary tumor samples (R = -0.23). Differential gene expression analysis and functional characterizations between mutant and wild-type tumors implicates the mutated cells in promoting cell proliferation at early stages of tumorigenesis. These results emerge uniquely from a systems-level analysis integrating multiple proteins in complexes and multiple cell types in heterogeneous tumors.
Citation Format: Maayan Baron, Trey Ideker. Desmosome mutations in melanoma promote cellular proliferation and disease progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 178.
Abstract 1789: Triggering anti-tumor immunity by overexpressing of MAVS in combination with PD-L1 ICB in immune insensitive colorectal cancers
Authors: Hwang Bin-Jin 
Published: July 2021

Abstract
While the use of immune checkpoint blockade (ICB) has gained significant traction as a viable therapy for cancers, many more cancers remain refractory to these immunotherapies due to their highly immunosuppressive tumor microenvironment (TME). From both the earlier published report and our analysis of clinical cohorts of colorectal cancer, we found that the expression of MAVS (Mitochondrial Antiviral Signaling Protein) was significantly reduced. Because MAVS are known to play a key role in the initiation of anti-viral innate immunity, we hypothesized that MAVS may be critical in anti-tumor immune response and tumor cells are under evolutionary pressure to reduce MAVS expression. As such, the stimulation of the MAVS pathway in tumor cells may be a necessary precursor to trigger anti-tumor immune response and reverse local immunosuppressive TME. To circumvent issues associated with intracellular double stranded RNA ligand stimulation, we exploited the ability of MAVS to constitutively polymerize and elicit broad downstream interferon signaling through an overexpression strategy. This approach provided a novel genetic mean to elicit ligand free innate immune signaling in the TME, which we found to elicit robust stimulation of multiple interferon genes. Overexpression of MAVS in colorectal cell lines stimulated significant anti-tumors responses in vivo, which we found to be primarily mediated through the induction of tumor antigen-specific adaptive immunity. Utilizing viral vectors overexpressing MAVS, we demonstrate significant induction of interferon responses among different types of tumor cells and different types of cells in the tumor microenvironment. Intra-lesional injection of tumors using these vectors elicited profound anti-tumor responses against primary tumors, as well as, an abscopal effect against syngeneic implanted tumors. Overexpression of MAVS also stimulated the expression of PD-L1 as an immunosuppressive feedback mechanism due to stimulation of the MAVS pathway. As such, we tested the combination of MAVS overexpression and PD-L1 ICB in colorectal cancers and found that this combination allowed for significantly improved anti-tumor immunity. In conclusion, our findings suggest that a combination of MAVS cancer gene therapy and ICB may offer an alternative approach to activate immunity in "immunologically cold" tumors.
Citation Format: Bin-Jin Hwang. Triggering anti-tumor immunity by overexpressing of MAVS in combination with PD-L1 ICB in immune insensitive colorectal cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1789.
Abstract 1820: Uncovering mechanisms of immune evasion in a novel immunogenic model of KRAS-mutant lung cancer
Authors: Boumelha Jesse , de Carné Sophie , Mugarza Edurne , Romero-Clavijo Pablo , Molina-Arcas Miriam , Downward Julian 
Published: July 2021

Abstract
Oncogenic KRAS mutations drive tumourigenesis in 30% of non-small cell lung cancer (NSCLC). Despite much effort, targeted therapies that aim to directly inhibit signalling pathways downstream of KRAS have limited clinical benefits for NSCLC patients, but the recent approval of PD-1/PD-L1 antibodies has led to striking durable responses. However, only a fraction of patients respond and therefore a deeper understanding of the mechanisms that drive immune evasion are required in order to broaden the clinical efficacy of immunotherapy. Increasing evidence suggests that oncogenic signalling pathways greatly influence the tumour immune landscape to impair anti-tumour immune responses. We therefore aim to understand the mechanisms by which KRAS signalling mediates immune evasion in lung cancer. Current mouse models of KRAS-mutant lung cancer are poorly immunogenic, limiting investigations into tumour-immune interactions. To overcome this, we generated a novel transplantable KRAS-mutant lung cancer model, KPAR1.3, which triggers spontaneous anti-tumour immune responses and is sensitive to immune checkpoint blockade. To identify mechanisms of immune evasion we carried out an in vivo pooled CRISPR-Cas9 screen targeting 240 KRAS-regulated genes using this novel immunogenic model. This identified a number of genes that increased sensitivity or caused resistance to anti-tumour immune responses. As an alternative approach we utilised the recently developed class of mutant-specific KRAS-G12C inhibitors to assess the impact of inhibiting KRAS signalling on anti-tumour immune responses in KPAR1.3 tumours. KRAS-inhibition stimulated adaptive immunity in vivo, which contributed to the response of KPAR1.3 tumours in immune-competent mice. Together these data suggest that targeting KRAS, or KRAS-driven mechanisms of immune evasion, could broaden the clinical efficacy of immunotherapy in KRAS-mutant NSCLC.
Citation Format: Jesse Boumelha, Sophie de Carné, Edurne Mugarza, Pablo Romero-Clavijo, Miriam Molina-Arcas, Julian Downward. Uncovering mechanisms of immune evasion in a novel immunogenic model of KRAS-mutant lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1820.
Abstract 1839: Nanobodies against EGF enhance the antitumoral effect of osimertinib and overcome resistance in non-small cell lung cancer cell models
Authors: Guardiola Salvador , Sánchez-Navarro Macarena , Giralt Ernest , Rosell Rafael , Codony-Servat Jordi 
Published: July 2021

Abstract
Background: The epidermal growth factor receptor tyrosine kinase inhibitor (EGFR TKI) osimertinib improves therapy for non-small cell lung cancer (NSCLC) patients who possess EGFR mutations. However, acquired resistance appears invariably due to several mechanisms. The strategy of using EGF-targeted nanobodies (Nbs) to block the initial step of the EGFR pathway constitutes a new research area. Nbs also offer several advantages compared to traditional mAbs, such as their reduced size, higher stability and tissue penetration, low production costs and lack of Fc effector function, which provide key advantages for targeting soluble tumoral growth factors. In this study we investigated the efficacy of anti-EGF Nbs to reduce osimertinib-resistance.
Experimental procedures: Cell viability and colony formation assays were performed in PC9 and PC9-osimertinib-resistant NSCLC cell lines tested with anti-EGF Nbs alone or in combination with osimertinib. To analyze the mechanism of action of these compounds and its combination, western blot analysis was carried out to study protein expression and activation.
Summary of data: Two anti-EGF Nbs, generated in our laboratory, inhibited cell viability and colony formation in PC9 and PC9-derived osimertinib-resistant cell lines. The combination of these Nbs with osimertinib improved the antitumoral efficacy of this EGFR-TKI in cell viability and colony formation experiments. The combination of anti-EGF Nbs with osimertinib clearly decreases the activation of proteins involved in the EGFR pathway, such as, EGFR, Akt and Erk 1/2. In addition, it increases cellular apoptosis, and decreases the expression of Hes1, a marker of cancer stem cells involved in metastasis and osimertinib resistance mechanisms.
Conclusions: We conclude that the combination of anti-EGF nanobodies and osimertinib exhibits a good efficacy in inhibiting cell viability and colony formation, while, inhibiting expression and activation of proteins involved in osimertinib resistance.
Citation Format: Salvador Guardiola, Macarena Sánchez-Navarro, Ernest Giralt, Rafael Rosell, Jordi Codony-Servat. Nanobodies against EGF enhance the antitumoral effect of osimertinib and overcome resistance in non-small cell lung cancer cell models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1839.
Abstract 1877: IOA-237 - A potent anti-CD73 mAb demonstrates monotherapeutic and combination efficacy in solid tumor models
Authors: Deken Marcel A. , Carruthers Alan M. , Niewola-Staszkowska Karolina , Gernon Gráinne , Sandig Hilary , Shah Pritom , Lahn Michael M. , Johnson Zoë 
Published: July 2021

Abstract
CD73, an ecto-5'-nucleotidase, is frequently overexpressed in the tumor microenvironment and can be found on tumor, stromal cells and immune cells. Its function is to catalyze the conversion of adenosine monophosphate (AMP) to adenosine and phosphate, both at the cell surface and as a soluble factor. CD73 has gained interest as a therapeutic target in cancer due to the immunosuppressive role of adenosine in the tumor microenvironment. IOA-237 is a fully human, phage derived monoclonal antibody fully cross-reactive to mouse and human and with high potency against soluble and cell surface CD73. This novel antibody demonstrates in vitro and in vivo characteristics that suggest a best-in-class potential. We demonstrate that IOA-237 is able to significantly reduce tumor outgrowth in multiple mouse models of solid tumors. In the low CD73 expressing CT26 mouse colorectal cancer model, monotherapeutic application of IOA-237 showed tumor outgrowth reduction compared with isotype control. Best-in-class potential was confirmed with head-to-head comparison against a clinical stage anti-CD73 mAb, MEDI9447. Furthermore, inhibition of CD73 by IOA-237 was combined with inhibitors of novel immuno-oncology targets to study complementary modes of action in mouse models of solid tumors. These data indicate the potential of IOA-237 in monotherapeutic and combination therapeutic approaches and warrants further development. Additional in vitro and in vivo efficacy studies are ongoing and non-clinical safety studies are being planned.
Citation Format: Marcel A. Deken, Alan M. Carruthers, Karolina Niewola-Staszkowska, Gráinne Gernon, Hilary Sandig, Pritom Shah, Michael M. Lahn, Zoë Johnson. IOA-237 - A potent anti-CD73 mAb demonstrates monotherapeutic and combination efficacy in solid tumor models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1877.
Abstract 1886: Anti -GPRC5D/CD3 T cell-redirecting bispecific antibody with potent in vitro and in vivo antitumor efficacy against multiple myeloma
Authors: Kodama Tatsushi , Kochi Yu , Nakai Waka , Mizuno Hideaki , Baba Takeshi , Habu Kiyoshi , Sawada Noriaki , Tsunoda Hiroyuki , Shima Takahiro , Miyawaki Kohta , Kikushige Yoshikane , Mori Yasuo , Miyamoto Toshihiro , Maeda Takahiro , Akashi Koichi 
Published: July 2021

Abstract
Background: Although treatment advances over recent decades have significantly improved survival of patients with multiple myeloma, there is still an unmet medical need for more effective treatments. The orphan G protein-coupled receptor, class C group 5 member D (GPRC5D), was previously identified as expressed by mRNA in patients with multiple myeloma with only low expression detected in normal tissues, but confirmation of protein expression remained elusive. In this study, we determined the cell surface expression of GPRC5D on malignant and normal hematological cells. In addition, we evaluated the antitumor activity and mechanism of GPRC5D TRABs in in vitro and in vivo mouse models.
Method & Results: We established specific monoclonal antibodies against human GPRC5D and identified its expression on the surface of malignant cells involved in multiple myeloma, but except for plasma cells and B cells, did not find it at appreciable levels on normal hematopoietic cells and bone marrow progenitors, including hematopoietic stem cells. To investigate whether GPRC5D could be therapeutic target, we generated IgG-based anti-GPRC5D/CD3 bispecific T-cell-redirecting antibodies (GPRC5D TRABs). GPRC5D TRABs induced T cell activation and the killing of a wide variety of GPRC5D expressing tumor cells in vitro. In mouse models with reconstituted human immune cells, GPRC5D TRABs showed strong antitumor efficacy against GPRC5D-positive tumors through the activation of T cells.
Conclusion: These findings suggest that GPRC5D is an antigen specific to multiple myeloma and a potential target of TRAB therapy.
Citation Format: Tatsushi Kodama, Yu Kochi, Waka Nakai, Hideaki Mizuno, Takeshi Baba, Kiyoshi Habu, Noriaki Sawada, Hiroyuki Tsunoda, Takahiro Shima, Kohta Miyawaki, Yoshikane Kikushige, Yasuo Mori, Toshihiro Miyamoto, Takahiro Maeda, Koichi Akashi. Anti -GPRC5D/CD3 T cell-redirecting bispecific antibody with potent in vitro and in vivo antitumor efficacy against multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1886.
Abstract 1896: The genomic features of Chinese cancer patients harboring HLA LOH
Authors: Zhao Jian , Hu Jie , Zhang Xiuqin , Gao Xuan , Tong Fan , Fu Xiaorui , Yi Yuting , Guan Yanfang , Xia Xuefeng , Huang Jian'an 
Published: July 2021

Abstract
HLA LOH is an immune escape mechanism subject to microenvironmental selection pressures in tumor evolution. In previous study, the prevalence of HLA LOH in Chinese cancer patients has been characterized. However, the genomic features of patients harboring HLA LOH remains unknown.
Methods
The sequencing data of 1021 cancer genes from 1504 advanced patients across 11 diverse cancer types was analyzed to investigate the internal relationship between HLA LOH and genomic alteration. Exon 2, exon 3, and bilateral introns of HLA-A/B/C genes were well covered in the 1021-gene panel. HLA LOH was analyzed using the LOHHLA algorithm.
Results
Consistent with previous study, we found that the occurrence of HLA LOH is related to genomic instability. In colorectal cancer, the HLA LOH ratio of MSS samples was significantly higher than that of MSI-H samples. Among the remaining 10 cancer types, the trend was consistent (Table 1). These results revealed that HLA LOH is a potential immune escape mechanism for MSS patients. In NSCLC and BRCA, HLA LOH is associated with an elevated TMB (p&lt;0.001, p&lt;0,05). The alteration frequency of TP53 and LRP1B in HLA LOH group was significantly higher than that in HLA stable group (p&lt;0.001, p=0.005, respectively). The occurrence of HLA LOH is also related to alterations in several important signaling pathways. The alteration frequencies of RTK/RAS pathway, p53 pathway, Notch pathway, Hippo pathway and Nrf2 pathway in the HLA LOH group were significantly higher than that in HLA stable group. These results are indicating that HLA LOH may mediate tumorigenesis by interfering with normal signaling transduction.
Conclusions and Discussion
Statistical results revealed that the occurrence of HLA LOH was related to genomic instability, including high TMB level and alterations in oncogenic signaling pathways, which may facilitate tumor formation. Overall, these findings may provide useful information for clinical practice and immunotherapy.
The correlation between MSI stage and HLA LOHCancer TypesMSIHLA LOHHLA stablePercent with HLA LOHP valueColorectal cancerMSS617146.2%0.025MSI-H31416.7%Remaining 10 cancer typesMSS48549949.3%0.031MSI-H51525.0%
Citation Format: Jian Zhao, Jie Hu, Xiuqin Zhang, Xuan Gao, Fan Tong, Xiaorui Fu, Yuting Yi, Yanfang Guan, Xuefeng Xia, Jian'an Huang. The genomic features of Chinese cancer patients harboring HLA LOH [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1896.