bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 1949: Caspase 3 plays a requisite role in regulating survival of human breast cancer cells
Authors: Eskandari Ebrahim , Eaves Connie J. , Tan Susanna 
Published: July 2021

Abstract
Caspase-3 has long been recognized for its key role as a protease that mediates the degradation of cellular components during the late stages of apoptosis. However, there is also a growing body of evidence that caspase-3 has essential intrinsic functions in regulating normal and malignant cell properties that are distinct from its apoptotic functions. In a previous study, we showed that a readily detectable but low proportion of freshly isolated normal human mammary cells with a luminal phenotype and a capacity to divide in vitro display a reversible expression of activated caspase-3, and subsequently it was found that suppression of caspase-3 expression in the MDA-MB-231 human breast cancer cell line contributes to its radiation-induced loss of proliferative activity in vitro. To further investigate the role of caspase-3 in normal and malignant human mammary cells, we constructed shRNA-caspase-3 and control lentiviral vectors to examine the effect of decreasing caspase-3 expression (2-fold determined by Western blot) in normal and transformed human mammary cell types. Knockdown (KD) of caspase-3 expression in 2 breast cancer cell lines (MDA-MB-231 and MCF7 cells) showed that caspase-3 KD suppressed their growth in vitro 5-fold within 8 days and inhibited formation of tumors in highly immunodeficient (NRG) adult female mice transplanted subcutaneously with shCaspase-3-transduced cells in contrast to controls in which 1cm diameter tumors appeared within 6 weeks. The shCaspase-3-transduced cells also showed a complete loss of lung metastasizing activity in intravenously injected mice. A similar anti-tumorigenic effect was also obtained in freshly isolated normal human mammary cells that were co-transduced with the shCaspase-3 vector as well as KRASG12D which otherwise causes the normal cells to produce invasive ductal carcinomas in subcutaneously transplanted immunodeficient mice. Annex V and propidium iodide staining of single-cell, as well as bulk cultures of the MDA-MB-231cells, showed that Caspase-3 is required for their survival as well as their growth. Surprisingly, initial parallel experiments with purified basal and luminal progenitor subsets of normal human mammary cells and the immortalized but non-tumorigenic MCF-10A cell line also indicates a significant suppression of cell growth in vitro within 10 days. These findings highlight the multiplicity of pro- as well as anti-survival activities that Caspase-3 exerts on normal and malignant human mammary cells raising important considerations of any therapy designed to augment their activity.
Keywords: Breast cancer, Caspase-3, Cell survival
Citation Format: Ebrahim Eskandari, Connie J. Eaves, Susanna Tan. Caspase 3 plays a requisite role in regulating survival of human breast cancer cells [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 1949.
Abstract 1956: Lycorine promotes cell senescence of hepatocellular carcinoma by regulating CDK1
Authors: Yu Haiyang , Yin Shuangshuang , Qiu Yuling , Luo Yanming , Hu Gaoyong , Lu Jia , Zhou Shiyue , Wang Tao 
Published: July 2021

Abstract
Hepatocellular carcinoma (HCC) is a serious threat to human health because of its high malignancy and low survival rate. The abnormal expression of genes along with the development of HCC, especially the genes related to the cell cycle. The abnormal expression of these genes in the growth of tumor cells makes them out of the original orbit and out of control. CDKs play critical part in cell cycle control, transcription, and development. Lycorine, a natural products, extract from lycoris radiate, possess biological activities. In this study, we found that Lycorine could up regulated the senescence related protein expression such as p16,p27,p21, however, CDK1 knockout also promote the occurrence of senescence. Unexpectedly, we found that lycorine inhibited CDK1 expression and promoted senescence with a dose-dependent manner in HCC cells, the results of CETSA and DARTS assay also showed that Lycorine could slow down the degradation rate of CDK1 protein; all findings indicated that lycorine might directly inhibit the expression of CDK1 to restrain the occurrence and development of HCC. These findings may provide a new perspective for the treatment of HCC.
Citation Format: Haiyang Yu, Shuangshuang Yin, Yuling Qiu, Yanming Luo, Gaoyong Hu, Jia Lu, Shiyue Zhou, Tao Wang. Lycorine promotes cell senescence of hepatocellular carcinoma by regulating CDK1 [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 1956.
Abstract 1960: Mechanisms of therapeutic synergy between pattern recognition response agonists and cdk4 inhibitors
Authors: Roulstone Victoria , Kyula Joan , Elliot Richard , Lord Christopher J. , Matthews Nik , Jennings Vicki , Whittock Harriet , Mansfield David , Choudhary Jyoti , Wright James , Yu Lu , Melcher Alan , Vile Richard , Coffey Matt , McLaughlin Martin , Harrington Kevin 
Published: July 2021

Abstract
Cytoplasmic nucleic acid sensors for double-stranded (ds) RNA (RIG-I/MDA5) and DNA (cGAS-STING) are pattern recognition receptors (PRRs) key to intracellular anti-viral responses. Recent research has highlighted roles for PRR agonists, including oncolytic virotherapy agents, in anti-tumor immunotherapy. Reovirus type 3 Dearing (Rt3D) is an oncolytic dsRNA virus with limited single-agent activity in clinical studies, but potential for use in combination regimens. We sought synergistic drug-virotherapy combinations using an unbiased screening approach that highlighted the CDK4/6 inhibitor, palbociclib, as a leading hit. We found that, when combined with Rt3D, palbociclib augmented oncolytic virus-induced endoplasmic reticulum (ER) stress/unfolded protein response (UPR) signaling. Combined Rt3D-palbociclib treatment potently increased interferon signaling and endogenous retroviral transcripts. Knockdown (siRNA) studies indicated key UPR proteins and the RNA sensor, RIG-I, were essential to the phenotype observed. Mechanistically independent experiments, using canonical RIG-I agonists and the ER stress inducer (thapsigargin), confirmed cross-talk between RNA sensing and ER stress pathways that augment cancer cell death and interferon production. Combined Rt3D-palbociclib increased innate immune activation and effector function. Our findings demonstrate that UPR signaling and innate immune RNA sensor crosstalk can be exploited to enhance anti-cancer efficacy with pro-immunogenic consequences. This has implications for future clinical development of PRR agonists and oncolytic viruses, as well as broadening the therapeutic remit of CDK4/6 inhibitors to include their role as ER stress sensitizers.
Citation Format: Victoria Roulstone, Joan Kyula, Richard Elliot, Christopher J. Lord, Nik Matthews, Vicki Jennings, Harriet Whittock, David Mansfield, Jyoti Choudhary, James Wright, Lu Yu, Alan Melcher, Richard Vile, Matt Coffey, Martin McLaughlin, Kevin Harrington. Mechanisms of therapeutic synergy between pattern recognition response agonists and cdk4 inhibitors [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 1960.
Abstract 1967: Chaperonin-Containing TCP1 complex (CCT) promotes breast cancer by targeting key cell cycle regulators
Authors: Ghozlan Heba H. , Showalter Adrian , Khaled Annette R. 
Published: July 2021

Abstract
CCT is a protein folding complex that interacts with known oncoproteins, but its role as a driver of oncogenesis is unknown. Elucidating interactions of CCT with cell cycle regulators could reveal the oncogenic potential of the chaperonin. CCT is multi-subunit complex composed of two stacked rings formed by eight distinct subunits (CCT1-8). While different CCT subunits are associated with cancer and other diseases, we found that the CCT2 subunit is upregulated in breast cancer and other cancers and that its expression inversely correlates with patients' overall and progression free survival. Mining datasets from TCGA revealed that amplification of CCT2 is the predominant genomic alteration occurring in cancer patients and that CCT2 is frequently co-amplified or co-expressed with other oncogenes such as MDM2, FRS2, YEATS4, and CDK4 found in the 12q13-15 amplicon. Genetic alteration of CCT2 significantly associates with worse clinical outcome for cancer patients. To investigate the functional outcomes of CCT2 overexpression in breast cancer, spheroid culture was used. A CCT2-FLAG lentiviral vector was used to transduce T47D and MCF7 luminal breast cancer cells and cells grown in ultra-low attachment plates to induce spheroid growth. Expression of CCT2 increased growth of spheroids as compared to lentiviral control cells. In contrast, CCT2 depletion impaired spheroid formation, instead causing formation of loose aggregates. CCT2 overexpression increased the proliferative potential of spheroid cells and promoted progression though the G1/S phase of the cell cycle in synchronized cells by increasing expression of cell cycle regulators like Cyclin D1, CDK2 and CDK4. After 8 days in spheroid culture, CCT2 overexpressing cancer cells resumed attachment when transferred into 2D culture conditions; these cells acquire anchorage dependent and independent growth capability, increased actin expression, and proliferated. These characteristics of CCT2 overexpressing cells may be indicative of supporting a more invasive and metastatic phenotype. In support, we discovered that, along with cell cycle genes, CCT2 overexpressed cells increased expression of MYC, suggesting the CCT2 could be a novel regulator of MYC expression. Our results contribute new knowledge on the role of CCT2 in uncontrolled breast cancer progression and proliferation by regulating cell cycle genes. The recurrent amplification of CCT2 in different cancer types along with other oncogenes like MYC, MDM2 and CDK4 support it is role as a potential oncogene and novel therapeutic target for breast cancer.
Citation Format: Heba H. Ghozlan, Adrian Showalter, Annette R. Khaled. Chaperonin-Containing TCP1 complex (CCT) promotes breast cancer by targeting key cell cycle regulators [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 1967.
Abstract 1971: RCC2 promotes glioblastoma through regulation of G2-M progression
Authors: Liu Tian , Or Penelope Mei-Yu , Wong Chi-Wai , Ho Wayne Lut-Heng , Cheung Stanley Kwok-Kuen , Wang Yubing , Chan Andrew M. 
Published: July 2021

Abstract
Regulator of chromatin condensation 2 (RCC2), also known as telophase disk protein of 60 kDa (TD-60), has been previously identified as a component of the chromosome passenger complex. Accumulating evidence suggested that RCC2 plays a vital role in the mitotic process and abnormal RCC2 expression is essential for cancer development including Glioblastoma Multiforme (GBM). GBM is the most lethal and frequent brain tumor. Even with the optimal therapy, the 5-year survival rate of GBM remains poor. TCGA data revealed an upregulation of RCC2 in human GBM. Our preliminary data showed that RCC2 was upregulated in PTEN knockout mice primary astrocytes, and loss of function of PTEN has been found in nearly 95% GBM patients. This indicated that RCC2 might act as a PTEN downstream regulator and promote glioblastoma progression. RCC2 has been reported to be essential for tumorigenesis which may act as a GEF for Rac1 or RalA GTPase. Coincidently, our study showed that silencing RCC2 could suppress GBM cell proliferation. Using RNA-seq, we identified 737 DEGs between control siRNA- and RCC2 siRNA-treated A1172 cells. GSEA analysis delineated G2-M progression as the most notably altered pathway by silencing RCC2. Indeed, we observed a G2-M arrest in cells with RCC2 silenced, suggesting that RCC2 is essential for G2-M progression. Additionally, the connectivity map (C-map) analysis was conducted and identified LY294002 and cephaeline as promising inhibitors for RCC2-associated gene signatures. Both LY294002 and cephaeline can synergistically inhibit glioblastoma cell viability with RCC2 silencing. In summary, our study demonstrated that RCC2 signaling is essential for GBM development. We provided evidence that RCC2 exerts a positive effect on G2-M progression. These findings may shed light on anti-RCC2 targeted therapy in GBM treatment.
Funding: This work is supported by a General Research Fund grant (#14113519) from the University Grants Committee of Hong Kong.
Citation Format: Tian Liu, Penelope Mei-Yu Or, Chi-Wai Wong, Wayne Lut-Heng Ho, Stanley Kwok-Kuen Cheung, Yubing Wang, Andrew M. Chan. RCC2 promotes glioblastoma through regulation of G2-M 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 1971.
Abstract 1972: A novel signaling pathway delays abscission in cytokinesis with chromatin bridges
Authors: Petsalaki Eleni , Zachos George 
Published: July 2021

Abstract
Chromatin bridges are strands of missegregated chromatin connecting the anaphase poles or daughter nuclei and have been linked to tumourigenesis. In response to chromatin bridges in cytokinesis, cells delay abscission, the severing of the narrow cytoplasmic canal that connects the two daughter cells, to prevent chromatin breakage or tetraploiudization that are associated with genomic instability and cancer predisposition. In mammalian cells, this abscission delay is called “the abscission checkpoint” and is dependent on the localization and catalytic activity of the Chromosomal Passenger Complex (CPC) at the midbody. The CPC comprises the catalytic subunit Aurora B kinase, the scaffolding protein INCENP and the non-enzymatic subunits Survivin and Borealin; however, the molecular mechanisms that signal chromatin bridges to the CPC have not been previously identified. In the present study, we show that inhibition of the DNA damage kinases ATM or Chk2 impairs CPC-localization to the midbody and correlates with premature abscission and chromatin breakage in cytokinesis with trapped chromatin in human carcinoma cell lines. ATM phosphorylates Chk2-threonine 68 (T68) to activate Chk2 at the midbody. In turn, active Chk2 phosphorylates INCENP at the newly identified site serine 91 (S91) to promote CPC-localization to the midbody, to delay abscission and prevent chromatin breakage. Expression of siRNA-resistant phosphomimetic mutant INCENP-S91D or GFP:INCENP(FB) that is constitutively targeted to the Flemming body (FB), but not WT INCENP, rescues CPC-midbody-localization and prevents chromatin breakage in Chk2-deficient or ATM-deficient cells. In contrast, in the absence of the endogenous INCENP, the non-phosphorylatable mutant INCENP-S91A does not localize to the midbody and its expression promotes chromatin breakage. Furthermore, the Mre11-Rad50-Nbs1 (MRN) complex is required for ATM activation at the midbody. These results identify an MRN-ATM-Chk2-INCENP signaling pathway that prevents chromosome breakage in cytokinesis with chromatin bridges, by promoting CPC-midbody localization.
Citation Format: Eleni Petsalaki, George Zachos. A novel signaling pathway delays abscission in cytokinesis with chromatin bridges [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 1972.
Abstract 199: Blossom AI: A novel drug discovery app for the prediction of hotspots on multiplex protein protein interaction complexes using random forest algorithms
Authors: Zhang Stephanie , Kang Minsoo 
Published: July 2021

Abstract
Protein protein interactions (PPIs) form the backbone of signal transduction pathways in diverse physiological processes, mediating the transmission and regulation of oncogenic signals essential to cellular proliferation and survival, thus representing a potential new class of drug targets for anticancer therapeutic discovery. However, several challenges face the targeting of PPIs, including large PPI interface areas, a lack of deep pockets, the presence of noncontiguous binding sites, and a general lack of natural ligands. The presence of hot spots (small subsets of amino acid residues that contribute significantly to free binding energy) makes PPIs amenable to small molecule perturbations, playing essential roles in the stability of protein binding. Effectively identifying which specific interface residues of protein protein complexes form the hot spots is critical for understanding the principles of protein interactions and has broad application prospects in protein design and drug development. This project presents Blossom AI, a novel, user friendly mobile app developed in XCode and CoreML that uses random forest decision tree algorithms (RF) to computationally predict the presence of hotspots on protein complexes within seconds, aiding the design of small molecule and peptide drugs that target protein-protein interactions, particularly for anticancer therapy. Leveraging features such as solvent accessible surface area (ASA), blocks substitution matrix, physicochemical properties (hydrophobicity, polarity, polarizability, propensities), position specific scoring matrix (PSSM) and solvent exposure, the RF is trained through a dataset of 313 mutated interface residues (133 hotspot residues and 180 non hotspot residues) from over 60 protein complexes to produce a training accuracy of 88.75%, validation accuracy of 92.86%, specificity of 87.18%, sensitivity of 75.38%, PPV 94.23%, NPV 86.61%. Blossom is high speed, low cost, and user friendly with significantly improved accuracy over the standard of alanine scanning mutagenesis.
Citation Format: Stephanie Zhang, Minsoo Kang. Blossom AI: A novel drug discovery app for the prediction of hotspots on multiplex protein protein interaction complexes using random forest algorithms [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 199.
Abstract 1999: DIRAS3 induces autophagy and enhances sensitivity to anti-autophagic therapy in KRAS-driven pancreatic and ovarian carcinomas
Authors: Bildik Gamze , Gray Joshua P. , Mao Weiqun , Bast Robert C. , Lu Zhen 
Published: July 2021

Abstract
Mutant KRAS drives human cancers from several sites, including pancreatic ductal adenocarcinoma (PDAC) and low-grade serous ovarian cancer (LGSOC). Despite the prevalence of RAS mutations in many different cancers, effective RAS-targeted treatment remains a challenge. More than 90% of PDACs are driven by mutant KRAS. Genetic suppression of KRAS or pharmacological inhibition of its effectors, ERK/MAPK, enhances the reliance of PDAC on autophagy that can provide a target for treatment. DIRAS3 (ARHI) is an imprinted tumor suppressor gene that is downregulated in pancreatic and ovarian cancers. When re-expressed, DIRAS3 blocks cancer cell proliferation, inhibits motility, and induces autophagy by multiple mechanisms. DIRAS3 inhibits RAS signaling by heterodimerizing directly with KRAS, inhibiting homodimerization of KRAS and disrupting KRAS nanoclustering. In this study, we tested whether inhibiting RAS signaling by re-expressing DIRAS3 would sensitize RAS-driven cancers to autophagy inhibition. Re-expression of DIRAS3 decreased phosphorylation of Erk1/2 (pThr202/Tyr204), inhibiting the RAF-MEK-ERK signaling pathway. Re-expression of DIRAS3 induced autophagic flux indicated by an increased LC3-mCherry/eGFP ratio. DIRAS3 re-expression decreased LKB1 (pS428) and increased AMPK (pT172) and ULK1 (pS555), suggesting that induction of autophagic flux may be partly mediated by the activation of the energy-sensing LKB1-AMPK1-ULK1 axis following suppression of upstream RAF-MEK-ERK signaling. In addition, we confirmed that DIRAS3-induced autophagy enhanced the sensitivity of cancer cells to autophagy inhibition as evidenced by decreasing the IC50 of both chloroquine (CQ) and di-chloroquine (DC661) in human KRAS-driven PDAC and LGSOC. The greater potency of DC661, blocking autophagy with an IC50 in the low nanomolar range, should prove more effective for combinatorial therapies in vivo.
Citation Format: Gamze Bildik, Joshua P. Gray, Weiqun Mao, Robert C. Bast, Zhen Lu. DIRAS3 induces autophagy and enhances sensitivity to anti-autophagic therapy in KRAS-driven pancreatic and ovarian carcinomas [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 1999.
Abstract 20: HiBiT tagging system for high throughput chemical screening for chemotherapy
Authors: Uchida Yutaro , Matsushima Takahide , Kurimoto Ryota , Chiba Tomoki , Inutani Yuki , Asahara Hiroshi 
Published: July 2021

Abstract
Chemical screening is an essential procedure for finding novel drugs of cancer treatments. Especially, cell-based screenings are mostly used for discovery of novel compounds or drug repositioning of already-used drugs. Cell viability or cell proliferation are usually used for evaluation of effects of candidate novel compounds for cancer treatments. However, high throughput system for rapid evaluation of endogenous target protein expression changes has not been established so far. Therefore, an easy and quick method for detection of endogenous target protein expression changes has been strongly needed for drug discovery. Herein, we established a novel chemical compound screening system using the HiBiT-tagging system for this aim using PD-L1 as an example. HiBiT tag is a small peptide tag composed of only 11 amino acids forming a dimer with LgBiT, and functions as a Nanoluciferase. The shortness of the peptide tag is useful for insertion of tag using genome editing technology. Thereby, we established a rapid chemical screening method using HiBiT-tagged cell lines created by CRISPR-Cas9 system. With this method, we made it possible to detect endogenous target protein expression changes within 10 minutes by just adding lytic buffer and LgBiT. For validation of this method, we performed chemical screening of PD-L1 using a HiBiT-tagged lung adenocarcinoma cell line with 1,280 compounds. As a result, we identified microtubule inhibitors as compounds upregulating PD-L1, and validated its upregulation of PD-L1 with qPCR and western blotting. In conclusion, we succeeded in establishing the method for chemical compounds detecting endogenous target protein expression changes with HiBiT-tagging system. Furthermore, we validated this method by performing chemical screening with PD-L1, and succeeded in identifying microtubules inhibitors as up-regulators of PD-L1.
Citation Format: Yutaro Uchida, Takahide Matsushima, Ryota Kurimoto, Tomoki Chiba, Yuki Inutani, Hiroshi Asahara. HiBiT tagging system for high throughput chemical screening for chemotherapy [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 20.