bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P108: In vivo CRISPR screens identify E3 ligase COP1 as a modulator of macrophage infiltration and cancer immunotherapy target
Authors: Wang Xiaoqing , Tokheim Collin , Gu Shengqing S. , Wang Binbin , Tang Qin , Li Yihao , Traugh Nicole , Zeng Zexian , Zhang Yi , Zhang Boning , Fu Jingxin , Xiao Tengfei , Li Wei , Meyer Clifford , Jiang Peng , Cejas Paloma , Lim Klothilda , Long Henry , Brown Myles , Liu X. Shirley
Published: December 2021

Despite remarkable clinical efficacies of immune checkpoint blockade (ICB) in cancer treatment, ICB benefits in triple-negative breast cancer (TNBC) remain limited. Through pooled in vivo CRISPR knockout (KO) screens in syngeneic TNBC mouse models, we found that inhibition of the E3 ubiquitin ligase COP1 in cancer cells decreases the secretion of macrophage-associated chemokines, reduces tumor macrophage infiltration, enhances tumor immunity and ICB response. Transcriptomics, epigenomics, and proteomics analyses revealed COP1 functions through proteasomal degradation of the C/ebpδ protein. COP1 substrate TRIB2 functions as a scaffold linking COP1 and C/ebpδ, which leads to polyubiquitination of C/ebpδ. COP1 inhibition stabilizes C/ebpδ to suppress the expression of macrophage chemoattractant genes. Our integrated approach implicates COP1 as a target for improving cancer immunotherapy efficacy by regulating chemokine secretion and macrophage infiltration in the TNBC tumor microenvironment.

Citation Format: Xiaoqing Wang, Collin Tokheim, Shengqing S. Gu, Binbin Wang, Qin Tang, Yihao Li, Nicole Traugh, Zexian Zeng, Yi Zhang, Boning Zhang, Jingxin Fu, Tengfei Xiao, Wei Li, Clifford Meyer, Peng Jiang, Paloma Cejas, Klothilda Lim, Henry Long, Myles Brown, X. Shirley Liu. In vivo CRISPR screens identify E3 ligase COP1 as a modulator of macrophage infiltration and cancer immunotherapy target [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P108.
Abstract P117: Oncogenic Kit induces replication stress and induces Chk1/ATR inhibitor sensitivity in melanoma
Authors: Njauw Ching-Ni , Ji Zhenyu , Tsao Hensin , Simoneau Antoine , Kumar Raj , Flaherty Keith T. , Zou Lee , Pham Duc Minh
Published: December 2021

Contrary to cutaneous melanoma (CM), Acral and mucosal melanomas (AMM’s) lack effective therapy and exact a higher mortality. Since amplifications and point mutations of KIT are common in AMM, we created a multi-stage murine cellular model of human KIT melanomas (i.e. mKitK641E lines) based on the most common KIT mutation in human melanoma (p.K642E). Compared to its vector-controlled cells (mVec), mKitK641E cells exhibit greater chromosomal aberrations, and sustain 3D spheroid forming capability and aggressive tumor growth in C57BL/6J mice. In addition, DNA replication/RNA processing and ribosomal biogenesis pathways associated with KitK641E transformation. Surprisingly, an unbiased comparative drug screen uncovered a selective vulnerability to Chk1 inhibition in the KitK641E activated cells. mKitK641E cells displayed >6-fold greater sensitivity compared to mVec cells (GI50=1.5 µM vs 10 µM) for Chk1 inhibitor PF477736 treatment. Furthermore, we proved that KitK641E induces profound DNA replication stress as evidenced by increased levels of γ-H2AX and p-RPA32Ser33 in replicating cells and defective replication fork progression. Thus, mKitK641E represents a novel model to study the biology of KIT-driven melanoma and therapy development.

Citation Format: Ching-Ni Njauw, Zhenyu Ji, Hensin Tsao, Antoine Simoneau, Raj Kumar, Keith T. Flaherty, Lee Zou, Duc Minh Pham. Oncogenic Kit induces replication stress and induces Chk1/ATR inhibitor sensitivity in melanoma [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P117.
Abstract P130: P-cadherin activates metabolic coupling in the tumor-mesothelial niche: From glycolysis through lactate to lipogenesis
Authors: Wang Kun , Ma Jing , Wong Carmen C. L. , Chan Chi Bun , Wong Alice S. T.
Published: December 2021

Peritoneal metastasis affects >70% ovarian cancer patients, and its effective management is an unmet medical goal. Successful adhesion to the peritoneal mesothelium is a key rate-limiting step for metastasis formation, but it is unclear the selective advantage of why ovarian cancer cells colonize specifically to the unique mesothelial environment. Metabolic reprogramming is a hallmark of cancers. Still their role in peritoneal metastasis remains to be fully understood. To overcome the limitations of a lack of tightly controlled experimental model to pinpoint key molecules causing metastasis, we have established an isogenic model of spontaneous human ovarian cancer metastasis. Metabolism is characterized using RNA-seq, RT-PCR, real-time cell metabolic assay, targeted lipidomic analysis and neutral lipid staining. Using coculture, we showed that HM but not NM specifically activated peritoneal mesothelium in a P-cadherin-dependent manner compared to other cadherins, suggesting that there is a unique role for P-cadherin. RNA-seq revealed distinct regulation of lipogenic pathway in non-specific or P-cadherin siRNA treated HM. For these, we have confirmed that P-cadherin could promote the expression of lipogenic genes ACLY, FASN and ACAT2 in HM. Concomitantly, P-cadherin activated glycolysis (HK2, Gpi and PGK1) in the mesothelial cells. Targeted lipidomic analysis further showed that lactate acid that was enriched in the mesothelium was shuttled from the mesothelium to the HM to fuel de novo lipid synthesis in HM, revealing a feed-forward positive loop. Suppressing lactate uptake by using a monocarboxylate transporter 1 inhibitor could abolish the metabolic crosstalk and subsequent metastatic outgrowth. Together, these findings reveal the metabolic differences between metastatic versus non-metastatic tumor cells in understanding ovarian cancer metastasis to the mesothelium, and suggest targeting P-cadherin could be a promising therapeutic approach (RGC17105919).

Citation Format: Kun Wang, Jing Ma, Carmen C. L. Wong, Chi Bun Chan, Alice S. T. Wong. P-cadherin activates metabolic coupling in the tumor-mesothelial niche: From glycolysis through lactate to lipogenesis [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P130.
Abstract P131: The role of UDP-6 glucose dehydrogenase (UGDH) in estrogen-mediated phenotypes in both estrogen receptor positive and estrogen receptor negative breast cancer
Authors: Price Meghan , Lavau Catherine , Baeta Cesar , Byemerwa Jovita , Wardell Suzanne , Brueckner Olivia , Mukherjee Debarati , Haynes Corinne , Nguyen Annee , Chang Chingyi , McDonnell Donald , Goodwin C. Rory
Published: December 2021

A better understanding of pathologic mechanisms underlying breast cancer progression and metastasis is critical to improve current treatment modalities. UDP-6- glucose dehydrogenase (UGDH) is an enzyme that has become a recent oncologic target of interest across various cancer subtypes for its role in increasing the aggressiveness and migratory capacity of tumor cells both in vitro and in vivo. UGDH is ubiquitously expressed and plays a critical role in forming the extracellular matrix (ECM), producing nucleotide sugars, and processing hormones through glucuronidation. For these reasons, investigating the effect of UGDH on breast cancer in the setting of hormonal stimulation is important. We found that knocking down UGDH in estrogen receptor positive (ER+) breast cancer cell lines (MCF7 marco and T47D) and an estrogen receptor negative (ER-) breast cancer cell line (MDA-MB-231) could abrogate estrogen induced migration-specific phenotypes in vitro. Furthermore, we found that knocking down UGDH mitigated estrogen stimulated primary tumor growth in vivo for both MCF7 macro and MDA-MB-231 mammary fat pad tumor models in mice. Thus, we found that UGDH regulates estrogen stimulated migratory phenotypes in both ER+ and ER- breast cancers in vitro and primary tumor growth in vivo. For this reason, UGDH and its associated pathways are promising targets for future drug development and small molecular targets in the treatment of both metastatic ER positive and ER negative breast cancers.

Citation Format: Meghan Price, Catherine Lavau, Cesar Baeta, Jovita Byemerwa, Suzanne Wardell, Olivia Brueckner, Debarati Mukherjee, Corinne Haynes, Annee Nguyen, Chingyi Chang, Donald McDonnell, C. Rory Goodwin. The role of UDP-6 glucose dehydrogenase (UGDH) in estrogen-mediated phenotypes in both estrogen receptor positive and estrogen receptor negative breast cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P131.
Abstract P166: The rs35112940 CD33 polymorphism reduces CD33 internalization and efficacy of CD33-directed gemtuzumab ozogamicin
Authors: Gbadamosi Mohammed O. , Shastri Vivek M. , Meshinchi Soheil , Lamba Jatinder K.
Published: December 2021

CD33 is a myeloid-specific cell surface protein widely expressed on acute myeloid leukemia (AML) cells making it an excellent immunotherapeutic target. Current CD33-directed immunotherapeutic treatment strategies include gemtuzumab ozogamicin (GO), an antibody-drug conjugate (ADC) approved in 2017 for treatment AML and other ADCs are various stages of development. Previously, studies from our group have identified germline variations in CD33 that are associated with CD33 cell surface expression levels and clinical outcomes in response to GO. Among these germline variations is rs35112940 (G>A; Arg304Gly), a missense polymorphism located in exon five of CD33 which is associated with lower CD33 expression and reduced benefit from treatment using GO. Herein, we functionally validated the effect of the rs35112940 variant by treating CD33KO-HL60 engineered to overexpress wildtype CD33 (HL60-CD33FL) or CD33 encoding the rs35112940 variant (HL60-CD33FL-rs35112940) with GO. After 48-hour treatment with 250 ng/mL of GO, we observed that HL60-CD33FL-rs35112940 cells were more resistant to GO than HL60-CD33FL cells (46.5% vs 66.4% cell viability, P = 0.02). Of note, all engineered cells expressed CD33 with less than 1-log fold difference in MFI (HL60-CD33FL median fluorescence intensity (MFI) vs HL60-CD33FL-rs35112940 MFI: 22536 vs 24882). One critical aspect of the mechanism of action of GO is the internalization of the GO-CD33 complex which allows free calicheamicin to induce DNA damage leading to cellular apoptosis. Given the proximity of the rs35112940 loci to the cytoplasmic immunoreceptor tyrosine-based inhibitory motif (ITIM) domain of CD33, which is critical for CD33 internalization, we hypothesized that the rs35112940 variation may impact CD33 internalization as well. To assess this, we performed a flow cytometry-based internalization assay to capture the remaining amounts of CD33 present on the cell surface after 4 hours allowing us to determine the internalization of CD33 over time. Over a 4-hour window, we observed that that HL60-CD33FL-rs35112940 cells had an approximate 10% reduction in CD33 internalization in comparison to HL60-CD33FL cells. Taken together these results provide insight into the effect of the rs35112940 variant on GO efficacy and CD33 biology, corroborating our previous findings, and support the use of CD33 polymorphisms to guide patient selection for treatment with GO.

Citation Format: Mohammed O. Gbadamosi, Vivek M. Shastri, Soheil Meshinchi, Jatinder K. Lamba. The rs35112940 CD33 polymorphism reduces CD33 internalization and efficacy of CD33-directed gemtuzumab ozogamicin [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P166.
Abstract P171: Ligand-displaying-exosomes using RNA nanotechnology for targeted delivery of multispecific drugs for liver cancer regression
Authors: Li Xin , Ellipilli Satheesh , Wang Hongzhi , Lee Wen-Jui , Ho Yuan Soon , Guo Peixuan
Published: December 2021

Liver cancer such as hepatocellular carcinoma (HCC) poorly responds to chemotherapeutics as there are no effective means to deliver drugs to liver cancer due to the intrinsic drug effluxion and detoxification properties of the liver. Exosomes are extracellular vesicles that deliver payload via a fusion mechanism to cell cytosol without endosome trapping. Here we report the use of GalNAc as ligands to decorate exosomes that loaded with anticancer therapeutics Paclitaxel (PTX) and miR122 that silence both the drug efflux pump MDR1 (multidrug-resistant protein-1) and the oncogenic gene ADAM10 (A Disintegrin and metalloproteinase domain-containing protein 10). GalNAc is the ligand that provides exosome targeting ability to bind the hepatocyte surface receptor ASGP-R (asialoglycoprotein-receptor) usually express on liver cancer cell surface abundantly. PTX is highly hydrophobic, when it is conjugated to a polymeric hydrophilic RNA as a prodrug, its water solubility increases 32000-fold. No toxicity was detected. The PTX conjugated RNA strands assembled into a 4-way junction RNA nanoparticle to harbor 24-copies of PTX and 1-copy of miR122. The 4WJ RNA nanoparticles are loaded into the exosome and are decorated with GalNAc as a targeting ligand using RNA nanotechnology. Binding studies demonstrated that the multispecific exosome selectively binds and internalizes into the HepG2 liver cancer cells, and delivers the PTX and miR122 into the cell cytosol, exhibiting the highest efficacy in killing the targeted cancer cells due to the multispecific effect comes from miR122, PTX, GalNAc, and Exos. The liver cancer tumor regressed significantly after systemic injection of the multispecific exosomes to mice xenograft-bearing liver cancer. The results demonstrate that exosomes can serve as a multivalent vector to carry ligands, RNAi, and chemical drugs as a multispecific strategy to treat incurable liver cancers.

Citation Format: Xin Li, Satheesh Ellipilli, Hongzhi Wang, Wen-Jui Lee, Yuan Soon Ho, Peixuan Guo. Ligand-displaying-exosomes using RNA nanotechnology for targeted delivery of multispecific drugs for liver cancer regression [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P171.
Abstract P177: NPEPPS regulates cisplatin-resistance and can be targeted to overcome treatment resistance in patient-derived bladder cancer tumoroids
Authors: Scholtes Mathijs P. , Akbarzadeh Maryam , Theodorescu Dan , Costello James C. , Mahmoudi Tokameh , Zuiverloon Tahlita C.M.
Published: December 2021

Gemcitabine/cisplatin combination is the recommended neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (MIBC) patients undergoing surgical removal of the bladder (cystectomy). Patients without residual tumor at cystectomy ,complete pathological response (pCR), have a good 5-yr OS of 80%. However, due to NAC resistance, only 25% of the patients achieve a pCR. This study aims to increase the number of patients reaching pCR by discovery and functional interrogation of novel and pharmacologically targetable mechanisms causal to NAC resistance. We have identified an M1 aminopeptidase, NPEPPS, to regulate intracellular cisplatin import through volume regulated anion channels (VRACs). We show that genetic inhibition of NPEPPS increases the intracellular concentrations of cisplatin, hereby re-sensitizing gem/cis-resistant BC cell lines. On the other side, NPEPPS over-expression enhanced resistance to cisplatin. Pharmacological inhibition of NPEPPS with tosedostat results re-sensitization of gem/cis resistant BC cells in vitro and in vivo. Additional therapeutically validation was performed in gem/cis resistant patient-derived tumoroids. For this purpose, tumoroid cultures were generated from bladder cancer patients whom did not respond to pre-operative gem/cis, molecularly characterized and compared to the tumor of origin. Comparison of bladder cancer specific hotspot mutations, copy-number aberrations and H&E staining confirmed that patient-specific tumor traits were maintained in ex vivo tumoroid cultures. Moreover, tumoroid cultures generated from NAC-resistant patients were also resistant to cisplatin concentrations that exceeded physiological serum concentrations. Interestingly, addition of NPEPPS-inhibitor tosedostat sensitized these NAC resistant tumoroids to serum concentrations of cisplatin. These findings have potential for rapid translation into the clinic and invite trials investigating tosedostat to overcome chemoresistance.

Citation Format: Mathijs P. Scholtes, Maryam Akbarzadeh, Dan Theodorescu, James C. Costello, Tokameh Mahmoudi, Tahlita C.M. Zuiverloon. NPEPPS regulates cisplatin-resistance and can be targeted to overcome treatment resistance in patient-derived bladder cancer tumoroids [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P177.
Abstract P180: Genetic screen identifies PDPK1 as a synergistic target to enhancing the efficacy of MEK1/2 inhibitors in NRAS mutant melanoma
Authors: Cai Weijia , Nguyen Mai , wilski nicole , purwin timothy , TiagodosSantos Manoela , Aplin Andrew
Published: December 2021

Melanomas frequently harbor activating NRAS mutations; however, there has been little advance in targeted therapy options for NRAS mutant melanoma patients. MEK inhibitors (MEKi) showed modest efficacy in clinic, which is insufficient to be approved by FDA. In this study, we performed a genome-wide CRISPR/Cas9-based screening, identified PDPK1 (Phosphoinositide-dependent kinase-1) as a therapeutic target to enhancing the efficacy of MEKi, and validated it in various NRAS mutant melanoma cell lines via pharmacological and genetic approaches. Combined inhibition of PDPK1 and MEK (PDPK1i+MEKi) profoundly inhibited NRAS mutant tumor growth in a xenograft model. Notably, the combinatorial treatment induced pyroptosis, and increased ratio of intratumoral CD8+ T cells, delayed tumor growth and prolonged survival in an immune competent allograft model whereas it showed a significantly weaker potency in an isogenic immune deficient model. These data suggest PDPK1i + MEKi is an efficient strategy against NRAS mutant melanoma in an immune-response-dependent manner. Significance: NRAS is still an 'undruggable' target in melanoma. Our discovery rationalizes the clinical development of PDPK1i plus MEKi in NRAS mutant melanoma patients and suggests further synergy of targeted therapy and immunotherapy.

Citation Format: Weijia Cai, Mai Nguyen, nicole wilski, timothy purwin, Manoela TiagodosSantos, Andrew Aplin. Genetic screen identifies PDPK1 as a synergistic target to enhancing the efficacy of MEK1/2 inhibitors in NRAS mutant melanoma [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P180.
Abstract P183: CRISPR screens identify sensitizers to trametinib in KRAS mutant cancer cell lines
Authors: Fenoglio Silvia , Cristo Aileen M. , Tepper James , Teng Teng , Meier Samuel R. , Choi Ashley , Zhang Hongxiang , Zhao Shan-chuan , Liu Shangtao , Ahronian Leanne G. , Aird Daniel , Das Nikitha M. , Yu Yi , Sjin Robert Tjin Tham , Andersen Jannik N. , Huang Alan , Li Fang , Pan Xuewen
Published: December 2021

KRAS is the most frequently mutated oncogene in human tumors and drives tumorigenesis across multiple lineages. Specifically, KRAS is mutated in about 30% of lung cancer and over 90% of pancreatic cancer. Despite recent progress in developing mutant selective KRASG12C inhibitors, patient treatment options for RAS activated cancers remain very limited. Targeting the MAPK pathway by means of MEK and ERK inhibitors has been explored as an alternative strategy for KRAS mutant cancer. However, the clinical benefit is modest due to drug resistance caused by reactivation of the MAPK pathway and potentially other pathways and/or bypass mechanisms. Here we used CRISPR-based screens to identify potential combination therapy targets to enhance trametinib response in KRAS mutant cancers. We screened in five KRAS mutant cell lines of lung and pancreatic lineages and identified both known as well as novel modulators of MEK inhibitor response. Consistent with previous reports, gene knockouts that impair the reactivation of ERK downstream of MEK inhibition scored as top hits in our drop-out screens. Knocking out MAPK1, RAF1, BRAF and PTPN11 sensitized all five cell lines to trametinib treatment supporting these as candidate drug combination targets for MAPK pathway inhibition. Our screens also identified multiple genes within the heparan sulfate pathway (EXT1, EXT2, EXTL3, XYLT2, ALG6, B3GAT3, B4GALT7 and HS2ST1) and the MAPK7 pathway (MAPK7 and MAP2K5) that sensitize multiple but not all cell lines to trametinib. As part of our target discovery platform, we further validated these screening results using various phenotypic assays. Altogether, our results suggest that resistance to MEK inhibitors is driven by reactivation of the MAPK pathway as previously demonstrated and that impairing such reactivation restores the sensitivity of KRAS mutant cancer cells to trametinib. The genetic mechanisms driving the MAPK pathway rebound are likely different in different cancers and understanding such mechanisms will be key for achieving clinical success.

Citation Format: Silvia Fenoglio, Aileen M. Cristo, James Tepper, Teng Teng, Samuel R. Meier, Ashley Choi, Hongxiang Zhang, Shan-chuan Zhao, Shangtao Liu, Leanne G. Ahronian, Daniel Aird, Nikitha M. Das, Yi Yu, Robert Tjin Tham Sjin, Jannik N. Andersen, Alan Huang, Fang Li, Xuewen Pan. CRISPR screens identify sensitizers to trametinib in KRAS mutant cancer cell lines [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P183.
Abstract P211: The investigational chemoprotection drug ALRN-6924, a dual inhibitor of MDMX and MDM2, shows potential for radioprotection
Authors: Annis Allen , Sutton David , Aivado Manuel , Vukovic Vojislav
Published: December 2021

Aim: We investigated whether p53 activation with ALRN-6924 can prevent toxicity in mouse models of acute radiation injury. Materials and methods: ALRN-6924 is a clinical-stage, first-in-class, stabilized cell-permeating alpha-helical peptide that disrupts the interaction of the p53 tumor suppressor protein with its endogenous inhibitors, MDMX and MDM2. In previous experiments it was shown that ALRN-6924 can induce transient, dose-dependent cell cycle arrest in the bone marrow to protect those cells from chemotherapy while not protecting p53-mutant cancer cells. Because radiation (like chemotherapy) preferentially affects proliferating cells, we hypothesized that ALRN-6924 may also protect proliferating cells in normal tissues from radiation-induced cellular toxicity. Cell cycle arrest was measured in the bone marrow of ALRN-6924-treated C57BL/6 mice by flow cytometry using EdU incorporation. Serum levels of macrophage inhibitory cytokine-1 (MIC-1), a biomarker of p53 activation, were measured by ELISA. Cell proliferation and apoptosis were measured in formalin-fixed mouse bone marrow by immunohistochemistry analysis of Ki67 and cleaved PARP, respectively. C57BL/6 mice (n=7/group) were treated with one or more intravenous 2.4 mg/kg doses of ALRN-6924 at 24, 16, 8, or 1 hour (or combinations thereof) or placebo prior to an abdominally targeted (shielded body) 15 Gy radiation dose and then monitored for body weight (BW). Results: MIC-1 was elevated in the serum of ALRN-6924-treated mice in a dose-dependent fashion. Repeated doses of ALRN-6924 every 8 hrs yielded sustained MIC-1 elevation, which correlated with reduced Ki67 positivity in the bone marrow. Treatment-dependent changes in cPARP expression were evident, but minimal in magnitude. In a nonlethal radiation exposure model, ALRN-6924 yielded significant protection from radiation-induced BW loss in a schedule-dependent manner. Placebo-treated mice showed 10% to 15% BW loss five days after irradiation, while mice receiving one or more ALRN-6924 doses 8 hrs prior to irradiation had an average of 4% BW loss (p=0.008, two-sided t test). Conclusions: ALRN-6924 mitigates toxicity in a mouse model of acute radiation injury. The observed radioprotection effect correlates with pharmacodynamic markers of cell proliferation and cell cycle arrest after one or more doses of ALRN-6924, and further supports previous demonstrations of chemoprotection with ALRN-6924. These results provide a rationale to investigate ALRN-6924 as a radioprotective agent.

Citation Format: Allen Annis, David Sutton, Manuel Aivado, Vojislav Vukovic. The investigational chemoprotection drug ALRN-6924, a dual inhibitor of MDMX and MDM2, shows potential for radioprotection [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P211.
Abstract P221: Discovery of a covalent inhibitor for an oncogenic mutant RhoAY42C
Authors: Guo Shirley , Cao Ping
Published: December 2021

Ras homolog family member A (RhoA) is a member of a larger family of Rho proteins of small GTPases, with structural and signaling similarities to Ras proteins. RhoA is involved in multiple cellular processes including cytoskeleton regulation and actin-myosin contractility, etc. Recent studies have shown that the most common RhoA mutation in diffuse gastric cancer (DGC), Y42C, causes a gain-of-function and is associated with the loss of the E-cadherin gene CDH (CDH1). Inhibitors of RhoAY42C could be promising agents for treating DGC that harbors CDH1 mutation/deletion. BridGene expressed RhoAY42C in cells, screened our proprietary covalent library against the RhoAY42C live cells, and employed our chemoproteomic platform IMTACTM (Isobaric Mass Tagged Affinity Characterization) to detect covalent labeling of the mutant RhoA protein. A pilot screening led to the successful identification of a covalent ligand of RhoAY42C, BGS1933. Mass spec analysis has confirmed the covalent modification of Cys42 in RhoA by BGS1933. Dose-dependent binding of BGS1933 to RhoAY42C was measured using an orthogonal fluorescence-based assay. The Cancer Genome Atlas (TCGA) study shows that ~1% DGC patients harbor the oncogenic mutant RhoAY42C. The discovery of a covalent inhibitor of RhoAY42C will enable us to validate the role of RhoAY42C in DGC and facilitate the development of new first-in-class targeted therapies for the treatment of gastric cancer.

Citation Format: Shirley Guo, Ping Cao. Discovery of a covalent inhibitor for an oncogenic mutant RhoAY42C [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P221.
Abstract P236: Targeting AXL/PDK1 signaling axis activates immunogenic cell death in liver cancer
Authors: Xie Yunong , Zhou Lei , Lin Cheuk Yin , Lee Terence , Ding Jin , Ma Stephanie , Tong Man
Published: December 2021

Hepatocellular carcinoma (HCC) is the most malignant form of primary liver cancers with poor prognosis. Majority of the cases are diagnosed in advanced stages where therapeutic options are limited and the response rates are low. There is an unmet clinical need for more effective therapeutic treatment. AXL is a receptor tyrosine kinase which belongs to the family of TAM receptors. Overexpression of AXL has been reported in multiple cancers, including HCC. We and others have also reported an up-regulation of AXL in sorafenib-resistant HCC. However, its role in regulating anti-tumor immunity in HCC is not fully understood. In this study, we observed an immunosuppressive gene signature in sorafenib-resistant HCC by RNA-Seq and pathway enrichment analysis. Genetic manipulation and pharmacological inhibition of AXL promoted immunogenic cell death in sorafenib-resistant HCC cells, as evident by increased surface calreticulin and HMGB1 secretion. PDK1, a key modulatory kinase downstream of AXL in the PI3K/Akt pathway, was also up-regulated in sorafenib-resistant HCC. Knockdown of PDK1 similarly led to an increased immunogenic cell death. In a sorafenib-resistant immunocompetent mouse HCC model, blockade of AXL with a selective AXL inhibitor increased tumor-infiltrating activated and proliferating CD8+ T cells, resulting in tumor suppression and prolonged survival of the mice. Taken together, our findings suggest that targeting the AXL/PDK1 signaling axis could be a viable therapeutic option which enhances anti-tumor immunity for the treatment of HCC.

Citation Format: Yunong Xie, Lei Zhou, Cheuk Yin Lin, Terence Lee, Jin Ding, Stephanie Ma, Man Tong. Targeting AXL/PDK1 signaling axis activates immunogenic cell death in liver cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P236.
Abstract P241: A highly potent HPK1 inhibitor augments immune cell activation and anti-tumor immunity in a syngeneic tumor mouse model
Authors: Liu Hao , Wu Lei , Feng Song , Huang Wei , Li Huijuan , Lin Jing , Liu Yangyang , Mei Liufeng , Ren Baoqi , Xie Julie , Yao Lili , Zhong Wenge
Published: December 2021

Background: HPK1 (MAP4K1) is a serine/threonine Ste20-related protein kinase that belongs to the mitogen-activated protein kinase (MAPK) family. HPK1 is mainly expressed in hematopoietic cells and serves as a negative regulator of anti-tumor immunity through modulating the activation of lymphocytes and dendritic cells. Upon TCR activation, HPK1 phosphorylates the adaptor protein SLP76 at Ser376 to destabilize the SLP76 microclusters, which leads to the attenuation of the TCR signaling. The reported anti-tumor efficacy data from HPK1 knockout and kinase-dead knock-in mouse models support HPK1 as a novel intracellular I/O target. Methods: Regor CARD platform (Computer Accelerated Rational Discovery) was deployed to identify potent and selective inhibitors of HPK1. Biochemical assays and primary human pan T cell-based cellular assays were utilized to support the structure-activity relationship (SAR) analysis and inhibitor optimization. In vitro and in vivo target engagement studies were conducted in Jurkat T cells and mouse splenocytes, respectively. In vivo efficacy study data were generated using CT-26 syngeneic tumor mouse model. Results: Highly potent HPK1 inhibitors with good selectivity against the liable immune kinases were identified. RGT-197, one of the lead inhibitors demonstrated a significant increase of IL-2 secretion in primary human pan T cells upon TCR activation. It inhibited TCR-induced phosphorylation of SLP76 at Ser-376 in vitro and in vivo. Anti-tumor efficacy was observed in CT-26 tumor-bearing mice by oral dosing of RGT-197 as a single agent and in combination with an anti-PD1-monoclonal antibody. Furthermore, RGT-197 increased the level of cytokines important for anti-tumor immunity in vivo. Conclusion: RGT-197, a potent and selective HPK1 inhibitor, provides a potential opportunity as a small molecule I/O agent to boost anti-tumor immunity either as monotherapy or in combination with immune checkpoint inhibitors.

Citation Format: Hao Liu, Lei Wu, Song Feng, Wei Huang, Huijuan Li, Jing Lin, Yangyang Liu, Liufeng Mei, Baoqi Ren, Julie Xie, Lili Yao, Wenge Zhong. A highly potent HPK1 inhibitor augments immune cell activation and anti-tumor immunity in a syngeneic tumor mouse model [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P241.
Abstract P254: Transcriptional effects in C26 tumor highlight mechanistic aspects of a novel dual MEK inhibitor, IMM-1-104
Authors: Kolitz Sarah E. , Fowler Kevin D. , King Peter J. , Zeskind Benjamin J. , Hall Brett M.
Published: December 2021

We developed a novel dual MEK inhibitor, IMM-1-104, that showed 94% tumor growth inhibition (TGI) in the syngeneic C26 mouse model through 10 days at 150 mg/kg (mpk) BID, with only 3.8% tumor-adjusted body weight loss (BWL) through 24 days. The mechanism differs from that of standard MEK inhibitors (MEKi), and leverages signaling dynamics to decouple efficacy and toxicity. IMM-1-104 achieves deep cyclic inhibition of the pathway rather than constant blockade, and prevents the RAF1 (CRAF) bypass which has hampered standard MEKi. In this study, we examined the transcriptional effects of IMM-1-104 in the C26 model via RNA sequencing. These observations confirmed the pattern of deep cyclic inhibition, demonstrating strong MAPK pathway inhibition in tumor 2h after treatment, and near complete release 12h following treatment. This pattern was observed both after the initial dose as well as following chronic BID dosing (18 days), indicating that deep cyclic inhibition was sustainable across chronic dosing. Filtering the transcriptional signatures to examine effects that followed the pattern of deep cyclic inhibition (strong effect at 2h and release at 12h) revealed effects on mitochondrial and metabolism genes. These genes included Hk2, which was downregulated more than 2-fold after 2h of treatment with 100 mpk IMM-1-104 both after the initial dose and following chronic BID dosing. The effect on Hk2 occurred in tumor but not in muscle tissue from the same mice. These results were independent of adaptive immunity, as they were also observed in nude mice. Top transcriptional effects of IMM-1-104 treatment in tumor also included an increase in expression of Wnt pathway genes at 2h, following either a single dose or chronic BID dosing, at both 25 and 100 mpk. This increase was also observed at 12h following the 100 mpk dose. Activation of Wnt signaling in CRC tumors has previously been reported with standard MEK inhibitors. The transcriptional profile of IMM-1-104 in the C26 model highlighted key aspects of its mechanism related to signaling dynamics, which helps explain its ability to achieve high TGI and tolerability. The profile also highlighted aspects shared with standard MEKi that could shed light on potential resistance pathways.

Citation Format: Sarah E. Kolitz, Kevin D. Fowler, Peter J. King, Benjamin J. Zeskind, Brett M. Hall. Transcriptional effects in C26 tumor highlight mechanistic aspects of a novel dual MEK inhibitor, IMM-1-104 [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P254.
Gender-Specific Differences of Renal Heat Tolerance in Older Adults during Heat Waves
Authors: Schanz Moritz , Kimmel Martin , Büchele Gisela , Lindemann Ulrich , Schricker Severin , Becker Clemens , Alscher Mark Dominik , Rapp Kilian
Published: December 2021

Background: Heat waves are known to cause increased morbidity and mortality in susceptible populations like old and functionally impaired people. The objective of the study was to assess renal tubular stress, a predictor for development of acute kidney injury, during heat waves in Central Europe. As a marker of renal tubular stress tissue inhibitor of metalloproteinases-2 [TIMP-2]·insulin-like growth factor binding protein-7 [IGFBP7], a new FDA-cleared renal tubular stress biomarker, was used. Materials and Methods: 68 residents from facilities of sheltered housing with urine samples collected at heat waves in 2015 and at control visits were included. Urinary [TIMP-2]·[IGFBP7] was compared between the heat waves and the control visits. Multivariate linear models were adjusted for age, frailty index, and functional comorbidity index. Results: The median age was 82.0 years, 82.3% were women. The percentage of elevated levels of urinary [TIMP-2]·[IGFBP7] (>0.3 [ng/mL]2/1,000) in the total study population was higher at the heat waves than at the control visits (25.0% vs. 17.7%). The effect of the heat waves on urinary [TIMP-2]·[IGFBP7] was stronger in men than in women: The percentage of elevated levels was 75.0% in men and 14.3% in women. In the multivariate analysis, the mean urinary [TIMP-2]·[IGFBP7] was 0.48 (95% CI 0.25; 0.70) (ng/mL)2/1,000 higher in men than in women. Except gender, a number of additional variables did not show an association with urinary [TIMP-2]·[IGFBP7] at the heat waves or the control visits. Conclusions: At heat waves, urinary [TIMP-2]·[IGFBP7] was elevated and higher in men than in women. This suggests gender-specific differences in renal heat tolerance in older people.
Statin Use and Incidence of Chronic Kidney Disease in Hypercholesterolemia Patients with Normal Renal Function
Authors: You Hyo-Sun , Shin Sang-Jun , Kim Joungyoun , Kang Hee-Taik
Published: December 2021

Introduction: Dyslipidemia is a known risk factor for chronic kidney disease (CKD). The effects of statins on CKD have already been studied in patients with CKD; however, data on the general population are limited. This study aimed to determine the relationship between statin use and the incidence of CKD in patients with hypercholesterolemia having normal renal function. Methods: A total of 7,856 participants aged 40–79 years at baseline (2009–2010) were included in the final analyses. The participants were divided into statin users (n = 4,168) and statin nonusers (n = 3,668), according to the statin usage. The Cox proportional hazard regression model was used to evaluate the adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for CKD. Results: The median follow-up duration was 5.8 years. A total of 543 cases of CKD (285 cases in males and 258 cases in females) occurred during the study period. The estimated cumulative incidence of CKD was significantly different between male statin nonusers and users (p < 0.001), while it was not statistically significant between female statin nonusers and users (p = 0.126). Compared with statin nonusers, the fully adjusted HRs (95% CIs) for CKD in statin users were 1.014 (0.773–1.330) in males and 1.117 (0.843–1.481) in females. Conclusion: Dyslipidemia is an obvious risk factor for CKD; however, statin use in patients with hypercholesterolemia having normal renal function does not demonstrate a clear relationship with the incidence of CKD.
Evolutionary and Allometric Insights into Anuran Auditory Sensitivity and Morphology
Authors: James Logan S. , Taylor Ryan C. , Hunter Kimberly L. , Ryan Michael J.
Published: December 2021

As species change through evolutionary time, the neurological and morphological structures that underlie behavioral systems typically remain coordinated. This is especially important for communication systems, in which these structures must remain coordinated both within and between senders and receivers for successful information transfer. The acoustic communication of anurans (“frogs”) offers an excellent system to ask when and how such coordination is maintained, and to allow researchers to dissociate allometric effects from independent correlated evolution. Anurans constitute one of the most speciose groups of vocalizing vertebrates, and females typically rely on vocalizations to localize males for reproduction. Here, we compile and compare data on various aspects of auditory morphology, hearing sensitivity, and call-dominant frequency across 81 species of anurans. We find robust, phylogenetically independent scaling effects of body size for all features measured. Furthermore, after accounting for body size, we find preliminary evidence that morphological evolution beyond allometry can correlate with hearing sensitivity and dominant frequency. These data provide foundational results regarding constraints imposed by body size on communication systems and motivate further data collection and analysis using comparative approaches across the numerous anuran species.
The Dynamic Effects of a Summer Learning Program on Behavioral Engagement in School
Authors: Pyne Jaymes , Messner Erica , Dee Thomas S.
Published: December 2021

Evidence that student learning declines or stagnates during summers has motivated an interest in programs providing intensive summer instruction. However, existing literature suggests that such programs have modest effects on achievement and no impact on measures of engagement in school. In this quasi-experimental study, we present evidence on the impact of a comprehensive and mature summer learning program that serves low-income middle school students and features unusual academic breadth, including a robust and well-designed social-emotional learning curriculum. Our results indicate that this program led to substantial reductions in unexcused absences, chronic absenteeism, and suspensions and a modest gain in English language arts test scores. We find evidence that the gains in behavioral engagement are dynamic, growing over time and with additional summers of participation.
A new species and a new record of Typhonium (Araceae) from southern Vietnam
Authors: VAN HONG THIEN , LE VAN SON , NGUYEN-PHI NGA , NGUYEN QUOC DAT , NGUYEN TRAN QUOC TRUNG , NGUYEN HIEU CUONG , LUU HONG TRUONG
Published: December 2021

Typhonium vietnamense is described as a new species from Vietnam. It is most similar to Typhonium varians but differs in a combination of leafy and floral characters. In addition, T. khonkaenensis is newly recorded for Vietnam, leading to exclusion of T. violifolium from the national flora. An updated key to all known species of Typhonium in Vietnam is given.
Nomenclature history and typification of Phacelurus speciosus (Poaceae) with a new synonym
Authors: CHORGHE ALOK R. , PATIL SAMEER C.
Published: December 2021

Nomenclature history related to the name Phacelurus speciosus has been discussed here. In absence of any original material a neotype is designated for the name P. speciosus. Additionally, the newly described species Rottboellia husainii is treated as a synonym of Phacelurus speciosus.
Neanotis prabhuii, a new species of Rubiaceae from Western Ghats, India
Authors: SUNIL CHANDRASSERIL NARAYANAN , SALIM PICHAN MOHAMMED , NARAYANAN MATALAI  KOKKARAMMATH RATHEESH , NITHYA VADASSERY MADHANAN , ANILKUMAR NADESAPANICKER , SANILKUMAR MALAYIL GOPALAN
Published: December 2021

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A Case Study of Cloud-Top Kelvin–Helmholtz Instability Waves near the Dendritic Growth Zone
Authors: Cann M. D. , Friedrich K. , French J. R. , Behringer D.
Published: December 2021

Kelvin–Helmholtz instability (KH) waves have been broadly shown to affect the growth of hydrometeors within a region of falling precipitation, but formation and growth from KH waves at cloud top needs further attention. Here, we present detailed observations of cloud-top KH waves that produced a snow plume that extended to the surface. Airborne transects of cloud radar aligned with range height indicator scans from ground-based precipitation radar track the progression and intensity of the KH wave kinetics and precipitation. In situ cloud probes and surface disdrometer measurements are used to quantify the impact of the snow plume on the composition of an underlying supercooled liquid water (SLW) cloud and the snowfall observed at the surface. KH wavelengths of 1.5 km consisted of ∼750-m-wide up- and downdrafts. A distinct fluctus region appeared as a wave-breaking cloud top where the fastest updraft was observed to exceed 5 m s−1. Relatively weaker updrafts of 0.5–1.5 m s−1 beneath the fluctus and partially overlapping the dendritic growth zone were associated with steep gradients in reflectivity of −5 to 20 dBZe in as little as 500-m depths due to rapid growth of pristine planar ice crystals. The falling snow removed ∼80% of the SLW content from the underlying cloud and led to a twofold increase in surface liquid equivalent snowfall rate from 0.6 to 1.3 mm h−1. This paper presents the first known study of cloud-top KH waves producing snowfall with observations of increased snowfall rates at the surface.
Different Responses of Central Asian Precipitation to Strong and Weak El Niño Events
Authors: Chen Zhang , Wu Renguang , Zhao Yong , Wang Zhibiao
Published: December 2021

The present study investigated impacts of strong and weak El Niño events on central Asian precipitation variability from El Niño developing years to decaying years. It is found that strong El Niño events persistently enhance central Asian precipitation from the mature winter to decaying summer. Large warm sea surface temperature (SST) anomalies in the tropical central-eastern Pacific induce anomalous upper-level divergence and updraft over central Asia through large-scale convergence and divergence in the mature winter and decaying spring. Meanwhile, the associated wind anomalies induce anomalous eastward and northeastward moisture flux from the North Atlantic and the Arabian Sea to central Asia. Both anomalous ascent and moisture flux convergence favor above-normal precipitation over central Asia in the mature winter and decaying spring. The El Niño events induced central Asian precipitation anomalies that are extended to the decaying summer due to the role of soil moisture. Increased rainfall in winter and spring enhances soil moisture in the following summer, which in turn contributes to more precipitation in summer through modulating regional evaporation. During weak El Niño events, significant wet anomalies are only seen in the developing autumn, which result from anomalous southeastward moisture flux from the Arctic Ocean, and the abnormal signals are weak in the other seasons. The different responses of central Asian precipitation to strong and weak El Niño events may be attributed to the difference in intensity of tropical SST anomalies between the two types of events.
A little Bethel and the pledge of God’s presence: worship in the household during and after the pandemic
Authors: Torvend Samuel
Published: December 2021

The COVID pandemic prompted most parishes to provide resources for worship in the household: service programs, websites with the Daily Office, pre-recorded worship, and live-streamed liturgies. Thus, the pandemic has drawn attention to household worship, a long-standing practice among Christians but one that has been frequently overlooked in seminary education and pastoral practice. This essay considers the sources alive in Anglican and Episcopal communities that support such practices and also considers the unfortunate tendency to create a learned dependency on religious professionals and the need to foster practices that cultivate Christian identity in the household.
Pre-Service Teachers’ Perceived Preparedness in Clinically Oriented and Traditional Teacher Preparation Programs
Authors: Zhang Jie , Cabrera Jill , Niu Chunling , Zippay Cassie , Dietrich Sylvia
Published: December 2021

This mixed-methods study compared teacher candidates’ (TCs) perceived preparedness in a clinically oriented teacher education model, Clinical Experiences and Practices in Teaching (CEPT), to a traditional model. Eighteen TCs participating in the CEPT model and 22 non-CEPT TCs were surveyed and interviewed after 1 year of the program. Clinical Experiences and Practices in Teaching teacher candidates reported more frequent participation in collaboration, networking, and mentoring than the non-CEPT teacher candidates. No group difference in TCs’ perceived preparedness to meet teaching standards was found. Interview data revealed that CEPT TCs experienced “reality shock” initially and developed greater teaching confidence and self-efficacy over two semesters.