bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 6139: Clinical implication of EZH2 inhibitors in hepatocellular carcinoma
Authors: Sohn Bo Hwa , Lee Sung Hwan , Jeong Yun Seong , Lee Ju-Seog 
Published: April 2023

Abstract
Background & Aim: Aberrant upregulation of EZH2 is frequently observed in hepatocellular carcinoma (HCC) and significantly associated with poor prognosis of HCC patients. While EZH2 inhibitors (EZH2i) are recently approved for treatment of lymphoma and sarcoma, their antitumor effect alone is not optimally efficacious against solid tumors like HCC. Ferroptosis is a newly discovered nonapoptotic type of cell death characterized by the iron-dependent accumulation of lipid hydroperoxides in cell membrane to lethal levels. Owing to anti-cancer effects of ferroptosis, many oncogenes are known to suppress ferroptosis. However, their mechanisms in HCC are currently unknown. We aim to uncover a novel mechanism for EZH2-mediated resistance to ferroptosis in HCC.
Methods: Multi-step analyses were performed with genomic data from mouse models (Ezh1/2 KO), cancer cell lines treated with EZH2i GSK126, and primary tumors including HCC to identify genetic networks or signaling/metabolic pathways associated with EZH2 in cancer cells. Functional connection of identified networks or pathways from the prediction analyses was tested in cell line models with various molecular biology approaches including western blots, colony forming assay, overexpression and/or depletion of genes of interest.
Results: Gene network analysis predicted that ferroptosis pathway is inhibited by EZH2. Interestingly, lipid biosynthesis is also identified as an inhibited metabolic pathway by EZH2. Since polyunsaturated fatty acid (PUFA) is essential for executing ferroptosis, we hypothesize that EZH2 suppresses ferroptosis by inhibiting synthesis of PUFA. HCC cells with high EZH2 expression have higher IC50 values to erastin, a ferroptosis inducer, than those with low EZH2 expression. Moreover, inhibition or depletion of EZH2 sensitize HCC cells to erastin-induced ferroptotic cell death, strongly suggesting that EZH2 accounts for resistance to ferroptosis. Mechanistically, EZH2 increases H3K27me3 methylation near PUFA gene promoters, leading to suppression of PUFA gene expression and subsequently low cellular PUFA level. Most interestingly, treatment of EZH2i significantly sensitized HCC cells with high EZH2 expression to erastin-induced ferroptosis, suggesting potential therapeutic opportunity for treatment of HCC patients with high EZH2 expression.
Conclusion: EZH2 is a novel suppressor of ferroptosis by negatively regulating lipid metabolism. Thus, our study provides scientific evidence for developing a novel therapeutic strategy for treatment of HCC patients with co-treatment of ferroptosis inducers and EZH2 inhibitors.
Citation Format: Bo Hwa Sohn, Sung Hwan Lee, Yun Seong Jeong, Ju-Seog Lee. Clinical implication of EZH2 inhibitors in hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6139.
Abstract 6142: Inhibition of both MAPK and AKT pathways overcomes resistance of NRAS-mutant melanoma stem cells to apoptosis
Authors: Alobaidi Ryyan , Islam Nusrat , Zhang Yanjun R. , Shamo Mathew M. , Allsup Samuel , Simbulan-Rosenthal Cynthia M. , Rosenthal Dean S. 
Published: April 2023

Abstract
Malignant melanoma is a lethal skin cancer containing melanoma-initiating cells (MIC) implicated in tumorigenesis, invasion, and drug resistance, and characterized by elevated expression of stem cell markers, such as CD133. We have shown that siRNA knockdown of CD133 enhanced apoptosis induced by the MEK inhibitor trametinib in melanoma cells. The current study investigates the underlying mechanisms of CD133's anti-apoptotic activity in patient-derived BAKP melanoma, harboring the difficult-to-treat NRASQ61K driver mutation, after either CRISPR-Cas9 CD133 knockout or Dox-inducible expression of CD133. CD133 knockout in BAKP cells increased trametinib-induced apoptosis by reducing anti-apoptotic BCL-xL, p-AKT, and p-BAD and increasing pro-apoptotic BAX. Conversely, Dox-induced CD133 expression diminished apoptosis in trametinib-treated cells, coincident with elevated pro-survival p-AKT, p-BAD, BCL-2, and BCL-xL and decreased activation of BAX and caspases-3 and -9. Inhibition of MEK with trametinib, in combination with pan-AKT inhibitor capivasertib (AZD5363) in BAKP cells with either CD133 overexpression or knockout in vitro reduced cell survival as measured by XTT, FACS analysis and colony formation assays. Further, in vivo studies with nude mice xenografted with Dox-inducible BAKP melanoma cells, showed significantly decreased tumor growth after xenografted mice were treated with trametinib alone or in combination with AZD5363. CD133 may therefore activate a survival pathway where (1) increased AKT phosphorylation and activation induces (2) BAD phosphorylation and inactivation, (3) decreases BAX activation, and (4) reduces caspases-3 and -9 activity and caspase-mediated PARP cleavage, leading to apoptosis suppression and drug resistance in melanoma. Targeting nodes of the AKT and MAPK survival pathways with both trametinib and AZD5363 highlights the potential for combination therapies for NRAS-mutant melanoma stem cells for the development of more effective treatments for patients with high-risk melanoma.
Citation Format: Ryyan Alobaidi, Nusrat Islam, Yanjun R. Zhang, Mathew M. Shamo, Samuel Allsup, Cynthia M. Simbulan-Rosenthal, Dean S. Rosenthal. Inhibition of both MAPK and AKT pathways overcomes resistance of NRAS-mutant melanoma stem cells to apoptosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6142.
Abstract 615: Spatially resolved expression of T cell receptors elucidates spatial relationships between T cells, immune infiltration, and cancer-associated pathways
Authors: van Raay Katrina , Kriner Michelle , Reeves Jason , Piazza Erin , Kaplan Hargita , Vivian John , Fernandez Francis , Hoang Margaret , Beechem Joseph 
Published: April 2023

Abstract
Spatial distribution of T cells is key in understanding the escape of tumors from immune surveillance via the adaptive immune response, including interactions between immune cells and the surrounding tumor microenvironment. T cells are critical to the adaptive immune response to pathogens and cancers, mediating an antigen-specific response through both specificity and diversity of T cell receptor (TCR) clonotypes. Many methods exist to determine specific clonotypes and overall TCR diversity present from bulk tissues or sorted cell populations; however, nearly all fail to capture spatial orientation and arrangement of T cells engaging with their microenvironment, and most require large amounts of starting material from precious samples. Here, we present a TCR expression profiling panel for the GeoMx® Digital Spatial Profiler that can be combined with the GeoMx Cancer Transcriptome Atlas (CTA) or Human Whole Transcriptome Atlas (WTA) on archival formalin-fixed paraffin embedded (FFPE) tissue specimens. This represents the first commercial spatial expression profiling assay for the simultaneous quantification of TCR constant, variable, and joining segments in situ.
We show reliable sensitivity and specificity (&gt;90%) with respect to orthogonal sequencing and robust detection of TCR chains with evidence of clonal expansion and CD8 infiltration across tumor regions in colorectal cancer tissue. These events also corresponded to increased signatures of exhaustion from the T cells and suggest that the T cells resident in or near the tumor are tumor-specific and poised for activation via checkpoint blockade. Signaling pathways and tumor-specific signatures were also evaluated to look for mechanisms through which tumor cells respond to T cell infiltration. We further validated the performance of the TCR probe pool in cell pellet arrays with orthogonal TCR sequencing, tonsil and colorectal cancer tissues.
Together, the combination of our TCR add-on panel with the CTA or WTA illuminates T cell phenotypes, signaling pathways, population dynamics, and transcriptomic changes, yielding an unparalleled view of the T cell response in any context.
FOR RESEARCH USE ONLY. Not for use in diagnostic procedures.
Citation Format: Katrina van Raay, Michelle Kriner, Jason Reeves, Erin Piazza, Hargita Kaplan, John Vivian, Francis Fernandez, Margaret Hoang, Joseph Beechem. Spatially resolved expression of T cell receptors elucidates spatial relationships between T cells, immune infiltration, and cancer-associated pathways [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 615.
Abstract 6152: Exploiting ferroptosis in mutant BAP1 uveal melanoma
Authors: Cunanan Camille J. 
Published: April 2023

Abstract
Uveal melanoma (UM) arises from melanocytes of the uveal tract in the eye and is the most common intraocular malignancy in adults. Primary UM lesions often harbor mutations in G-proteins, GNAQ or GNA11, and are successfully treated by radiotherapy or enucleation. However, 50% of patients develop metastases. Of these metastatic UM (MUM) patients, 80%develop metastases to the liver, an effect strongly correlated with the loss of function of BAP1,a nuclear deubiquitinase. BAP1-mutant MUMs are less responsive to conventional treatments, such as chemotherapy and immune checkpoint inhibitors, with 50% of these patients having an overall survival of only 1 year. We propose that the unique metabolic intermediates found in liver microenvironment may dictate MUM tropism, aggressiveness, and poor therapeutic response. Here, using a combination of in vitro and ex vivo liver slice cultures, we found that the liver microenvironment induces gene expression alterations consistent with limiting the toxicity of reactive oxygen species (ROS). Importantly, we note that mutant BAP1 UM displayed improved ROS detoxification compared to its wildtype counterparts. Furthermore, publicly available datasets suggest patients with mutant BAP1 UM, the subset of patients with liver metastases, have corresponding ROS detoxification gene expression patterns. These findings suggest that the liver microenvironment and BAP1 loss directs MUM to mitigate ROS-associated toxicity. This compensatory mechanism may be therapeutically exploited and pair well as a combination treatment with the recently approved bispecific agent, Tebentafusp, to selectively target liver MUM.
Citation Format: Camille J. Cunanan. Exploiting ferroptosis in mutant BAP1 uveal melanoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6152.
Abstract 6182: Tumor treating fields (TTFields) concomitant with PARP inhibitors or carboplatin for treatment of ovarian cancer cell lines
Authors: Martinez-Conde Antonia , Ene Hila , Frechtel-Gerzi Roni , Dor-On Eyal , Haber Adi , Giladi Moshe , Weinberg Uri , Palti Yoram 
Published: April 2023

Abstract
Purpose/Objectives: Ovarian cancer continues to be the leading cause of death among gynecological malignancies. Platinum-based chemotherapy is recommended after surgery for most patients with ovarian cancer; and PARP inhibitors (PARPi) are suggested as maintenance therapy. Both therapies induce DNA damage that require the proper activity of the Fanconi Anemia (FA)- BRCA pathway for its resolution, and hence are most beneficial in cancers with a BRCA mutation. However, 75% of patients with ovarian cancer do not harbor BRCA mutations, and thus may experience limited benefit from these treatments. TTFields are electric fields that disrupt cellular processes critical for cancer cell viability and tumor progression, ultimately leading to cancer cell death. Recently, TTFields have been shown to induce a state of BRCAness in various cancer types, and to be effective in ovarian cancer pre-clinical models. The objective of the current study was to examine the effect of TTFields concomitant with carboplatin or PARPi on ovarian cancer cell lines.
Materials/Methods: A2780 (BRCA wild type) and OVCAR3 (BRCA mutated) ovarian carcinoma cells were treated with TTFields (72 h, 1 V/cm RMS, 200 kHz), alone or with concomitant application of carboplatin or the PARP inhibitors olaparib or niraparib. Efficacy was examined via measurements of cell count, colony formation, and induction of apoptosis. The overall effect was calculated by multiplying cell count with colony formation.
Results: Application of TTFields to A2780 or OVCAR3 cells resulted in reduced cell count, increased overall effect, and elevated apoptosis. Carboplatin, olaparib, and niraparib each displayed dose dependent effects in both cell lines, with higher sensitivity demonstrated in the BRCA mutated cells. Concomitant application of TTFields with any of these drugs displayed a synergistic interaction in the BRCA wild type A2780 cells and an additive effect in the BRCA mutant OVCAR-3 cells.
Conclusions: The data suggest potential benefits for TTFields concomitant with platinum-based chemotherapy and PARPi in ovarian cancer, even in the absence of background BRCA mutations, in accordance with the BRCAness state induced by TTFields. As such, TTFields may enhance the efficacy of treatment for ovarian cancer in both the adjuvant and maintenance settings.
Citation Format: Antonia Martinez-Conde, Hila Ene, Roni Frechtel-Gerzi, Eyal Dor-On, Adi Haber, Moshe Giladi, Uri Weinberg, Yoram Palti. Tumor treating fields (TTFields) concomitant with PARP inhibitors or carboplatin for treatment of ovarian cancer cell lines. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6182.
Abstract 62: Untangling the connection between stress and metastatic breast cancer
Authors: He Xue-Yan , Ng David , Gao Yuan , Michalopoulou Evdokia , George Shanu , Adrover Jose M. , Sun Lijuan , Albrengues Jean , Wan Ledong , Han Xiao , Vakoc Christopher , Van Aelst Linda , Egeblad Mikala 
Published: April 2023

Abstract
There is emerging evidence that exposure to chronic stress is associated with increased risk of metastasis and poor survival in cancer patients. However, the underlying molecular and cellular mechanisms responsible for the effects of stress on tumor progression remain unclear. To determine how stress promotes metastasis, we established new mouse models in which multiple chronic stress exposure promoted breast cancer metastasis to the lungs. We found that chronic stress generates a pro-metastatic lung microenvironment with e.g., reduced T cell infiltration and increased extracellular matrix (ECM) deposition and neutrophil infiltration. Among them, neutrophils were required for these changes as their depletion abolished the pro-metastatic effects of stress and normalized the lung tumor microenvironment. Mechanistically, we analyzed neutrophils from chronically stressed mice and identified dramatically altered transcriptomes, including increased expression of several glucocorticoid receptor regulated genes. Phenotypically, neutrophils from stress exposed mice exhibited increased ROS production, and an increased ability to inhibit T cell activation and to form spontaneous neutrophil extracellular traps (NETs). The stress-associated changes to neutrophils were dependent on glucocorticoid receptor (GR) signaling as neutrophil-specific GR knockout mice showed no increase in NET-formation, a normalized lung microenvironment and no increase in lung metastasis upon stress exposure. Among the changes in the neutrophils caused by stress exposure, we found that the formation of pro-metastatic NETs was critical as directly digesting NETs with DNase I prevented stress-induced metastasis and normalized the lung microenvironment. In sum, this work shows that chronic stress exposure causes a glucocorticoid-mediated increase in NET formation and that NETs are critical drivers in the establishment of a stress-induced, metastasis-promoting microenvironment. Targeting NETs could be an important strategy to prevent metastatic recurrence in cancer patients, many of whom will experience stress due to their cancer diagnosis and subsequent treatments.
Citation Format: Xue-Yan He, David Ng, Yuan Gao, Evdokia Michalopoulou, Shanu George, Jose M. Adrover, Lijuan Sun, Jean Albrengues, Ledong Wan, Xiao Han, Christopher Vakoc, Linda Van Aelst, Mikala Egeblad. Untangling the connection between stress and metastatic breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 62.
Abstract 620: Regulation of anti-tumor immune response by EphA2 receptor tyrosine kinase
Authors: Shi Roger Xiaojun , Lingerak Ryan , Kim So-Yeon , Wang Wei , Sossey-Alaoui Khalid , Wang Bingcheng 
Published: April 2023

Abstract
Eph receptors are the largest family of receptor tyrosine kinases. Overexpression of EphA2 is common across many types of human cancer, particularly in the late stage malignant diseases. We report here that EphA2 knock-out causes delayed tumor growth in several syngeneic mouse caner models, such as breast, colon, lung, and prostate cancer as well as melanoma. However, such effects are missing in immune deficient mice, which suggests the involvement of immune components. Immunophenotyping of the tumors shows elevated T cell infiltration and accompanied by reduced MDSC population in the EphA2 KO tumors. Single cell transcriptomic analysis and cytokine measurements support these results showing increased production of CCL5, CXCL9 and IFNg in the EphA2 KO tumors. Analysis on tumors at very early time points reveals elevated levels of CXCL1 and CXCL2 which recruits suppressive MDSCs. Consistently, larger population of MDSCs was found in PBMCs from the control tumor bearing mice than those bearing EphA2 KO tumors. These results suggest that EphA2 in cancer cells drive the production of CXCL1 and CXCL2 to recruit suppressive MDSCs to the tumor site, thus subvert the host anti-tumor immune surveillance. Targeting the overexpressed EphA2 in cancer can help reshape the tumor micro- environment towards type I anti-tumor immune response.
Citation Format: Roger Xiaojun Shi, Ryan Lingerak, So-Yeon Kim, Wei Wang, Khalid Sossey-Alaoui, Bingcheng Wang. Regulation of anti-tumor immune response by EphA2 receptor tyrosine kinase [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 620.
Abstract 6201: Identification of SP-002, a highly selective USP1 inhibitor effectively inhibits HRD tumor growth and displays low hematotoxicity risk
Authors: Zhou Feng , Li Zhengtao , Zhou Lei , Zhu Wei , Zhang Jiyan , Yang Wenqing , Xue Liting , Qin Xiaokang , Chen Ping , Tang Renhong 
Published: April 2023

Abstract
Tumors with homologous repair deficiencies (HRD) are sensitive to agents interrupting DNA repair. The deubiquitinase USP1 involves in the DNA damage response by translesion synthesis and Fanconi anemia pathway. And the synthetic lethality of USP1 and HRD is well reported. Moreover, deficiency of USP1 or its downstream pathway leads to hypersensitivity of HRD tumors to PARP inhibition. In addition, target-related hematotoxicity is widely observed in serval DNA Damage Response (DDR) pathway inhibitors, including PARP and ATR inhibitors, which limits the combination therapy. Here, we reported SP-002, a highly selective USP1 inhibitor, displayed monotherapy potential and combination activity with PARP inhibitor in HRD cancers. In the biochemical assay, SP-002 strongly inhibited USP1 enzyme with IC50 of 15.7 nM, and potently inhibited proliferation of BRCA1-mutant MDA-MB-436 breast cell (GI50, 47.4 nM). SP-002 demonstrated synergistic anti-proliferation effects in combination of olaparib, a PARP inhibitor, in MDA-MB-436 cells. And further results revealed that the combination significantly enhances the DNA damage burden and cells apoptosis. Moreover, synergistic activities of SP-002 and olaparib also were observed in a panel of HRD cell lines, such as UWB1.289, Capan-1, MDA-MB-453 and NCI-H292. In a human hematopoietic stem cells based in vitro hematotoxicity assay, SP-002 showed no significant inhibition on lineage-specific (myeloid, erythroid, and megakaryocytic) cell differentiation and survival. In comparison, positive controls, 5-fluorouracil and olaparib significantly attenuated those primary cells both on differentiation and survival, which was consistent with the hematological toxicity observed in human. Oral administration of SP-002 led to completely tumor growth inhibition in MDA-MB-436 xenograft model, and combination of SP-002 and olaparib resulted in tumor regression. In conclusion, SP-002, a selective and potent USP1 inhibitor without significant hematotoxicity, that demonstrated excellent efficacy on treatment of HRD cancers.
Citation Format: Feng Zhou, Zhengtao Li, Lei Zhou, Wei Zhu, Jiyan Zhang, Wenqing Yang, Liting Xue, Xiaokang Qin, Ping Chen, Renhong Tang. Identification of SP-002, a highly selective USP1 inhibitor effectively inhibits HRD tumor growth and displays low hematotoxicity risk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6201.