bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 546: Targeting BRAF mutations in head and neck cancer
Authors: Law Chun Ho , Chan Franky Leung , Lui Vivian Wai Yan 
Published: June 2023

Abstract
The mitogen-activating protein kinase (MAPK) pathway [RAS/RAF/MEK/MAPK] is a well-known mitogenic pathway essential for regulation of cell proliferation, survival, differentiation, invasion, and apoptosis, etc. In normal cells, upon the binding of external stimuli, activated Ras relays the signals through a RAF-MEK-ERK (MAPKKK-MAPKK-MAPK) phosphorylation cascade, leading to MAPK pathway activation. On the other hand, in cancer cells, aberrations or mutations of the pathway components usually could lead to constitutive activation of the pathway, resulting in dysregulation of these cellular processes. Notably, mutations of MAPK pathway components are found in 18% of head and neck cancer (HNC). Among these, mutations of the serine/threonine-protein kinase B-Raf (BRAF gene) account for about 1.8% of HNC (based on TCGA-HNSCC cohort, USA). Serving as one of the key kinase members of the MAPK pathway, BRAF is considered as a precision drug target in various cancer types, including melanoma, thyroid cancer, and non-small cell lung cancer (NSCLC). While the significance of BRAF mutations remains underexplored in HNC, exceptionally favorable responses to BRAF and MEK inhibition had been reported in HNC patients carrying BRAF-mutations. Based on this, we hypothesize that BRAF mutations may confer drug sensitivity and serve as a predictive biomarker for personalized therapy in HNC. Here, we demonstrated that ectopic overexpression of mutated BRAF resulted in MAPK pathway activation in HNC cell models. We also showed that ectopic BRAFV600E could promote the in vitro growth of head and neck cancer cells in both 2D and 3D culture conditions as well as enhance anoikis resistance, which is a prerequisite for metastasis. Further preliminary results showed that the mutated BRAFV600E mutant could promote the invasiveness of HNC cells. In summary, our findings support that targeting the BRAF mutants could be a potential therapeutic approach or precision treatment for HNC. (This study was supported by the Research Impact Fund (R4015-19F in the period of 6/29/2020-9/7/2021) from the Research Grants Council, University Grants Committee, Hong Kong SAR.)
Citation Format: Chun Ho Law, Franky Leung Chan, Vivian Wai Yan Lui. Targeting BRAF mutations in head and neck 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 546.
Abstract 5523: Impact of COVID-19 on longitudinal breast cancer research studies involving TNBC patients
Authors: Bates Cherie , Kong Esther , Zaikova Elena , Aparicio Samuel , Gelmon Karen 
Published: June 2023

Abstract
Background Triple-negative breast cancer (TNBC) accounts for ~15% of breast cancer diagnoses but is linked to worse outcomes and comprises a disproportionate number of breast cancer deaths. The TNBC pilot study is a prospective longitudinal study to provide a critical resource for understanding TNBC disease. However, the pandemic impacted the collection of samples.
Objective To highlight the impacts of COVID-19 on this longitudinal cancer translational research study including the patient's perspective and to develop recommendations to avoid future disruptions.
Methods 389 participants were enrolled in the prospective longitudinal cohort, which collected serial blood samples for up to 5 years. Due to the pandemic, research was curtailed for 6 months due to concerns about patient safety, halting the collection of blood samples. Missed samples and data gaps were documented. To complement this, we initiated a survey capturing the patient perspective on their experience of the study disruption due to COVID.
Results 217 enrolled participants missed a blood draw or had a collection outside the study window. 158 patients missed 1 time-point collection, and 59 patients missed ≥ 2 collections. Of the 217 participants who missed a collection, 6 disease recurrence diagnoses and 3 deaths occurred during research curtailment. The collection of survey responses from participants is ongoing and will be presented at the AACR Annual Meeting.
Conclusion Missed samples resulted in irreplaceable data gaps critical to monitoring patient outcomes, and reduced cohort sampling during the pandemic. Our current knowledge of the risks suggests that with proper informed consent, collections could have continued. To mitigate disruption in future clinical studies, clear plans should be part of study design to provide continuity. The participants’ experience to be reported will also help researchers understand their issues and help develop policies.
Missed collections and clinical events during COVID-19 research curtailment Number of patients Total with missed or late blood draws 217 Missed 1 collection 158 Missed ≥ 2 collections 59 Diagnosed with disease recurrence 6 Deaths 3
Citation Format: Cherie Bates, Esther Kong, Elena Zaikova, Samuel Aparicio, Karen Gelmon. Impact of COVID-19 on longitudinal breast cancer research studies involving TNBC patients. [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 5523.
Abstract 56: Unlocking primary cell culture for more relevant in vitro models
Authors: Theek Benjamin , Franke Anne , Agorku David , Lamfried Katharina , Jelveh Nojan , Linnebacher Michael , Carrera Lilian Martinez , Hardt Olaf 
Published: June 2023

Abstract
Tumor cell lines are commonly used to investigate biological and translational questions. However, many cell lines have been cultured in serum-containing medium for decades, continuously accumulating genetic and epigenetic aberrations. Without a doubt, these cell lines have very little in common with the tumor they originate from, resulting in low biological and clinical relevance. Despite these drawbacks, cell lines are still the most frequent research tool when it comes to the use of ex vivo models. Yet, in light of higher consistency, reproducibility, and biological relevance, more and more researchers are paying attention to which cells and culture medium to use. Although primary cell cultures certainly reflect cellular and genetic heterogeneity of the original tumor, finding a suitable medium that supports their growth and maintains genetic heterogeneity remains challenging. To this end, we developed serum-free cell culture media to cultivate primary epithelial tumor cells of pancreatic, renal, and ovarian origin. Notably, generating in vitro models with high biological relevance was successful when using our media during the derivation and expansion of tumor cell lines from primary and xenotransplanted tumors. Here, we present another serum-free cell culture media supporting the in vitro growth of primary colon adenocarcinoma. Using this optimized medium, we had a 42% success rate in establishing a primary cell culture for a given tumor sample, higher than for any other media tested in our hands. Next to 2D cell culture, our formulation supports 3D tumoroid formation when cells are embedded in a basement membrane matrix. Furthermore, targeted sequencing of 486 tumor-associated genes revealed that more than 99% of the detected genetic variants in an early passage (p11) were also present after extended time in culture (p53). In summary, our new serum-free medium enables the efficient derivation and expansion of primary tumor and xenograft-derived colon adenocarcinoma cell cultures in 2D and 3D, yet retaining their genetic identity.
Citation Format: Benjamin Theek, Anne Franke, David Agorku, Katharina Lamfried, Nojan Jelveh, Michael Linnebacher, Lilian Martinez Carrera, Olaf Hardt. Unlocking primary cell culture for more relevant in vitro models [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 56.
Abstract 5602: Markers of hypoxic cells: Testing a pre-clinical detection assay
Authors: Zayas Beatriz , Rios Karoline , Ortiz Luis , Cox Osvaldo 
Published: June 2023

Abstract
The proposed project aims to test the applicability of a novel set of patented organic compounds as markers of hypoxic circulating tumor cells (H-CTC) with potential pre-clinical relevance. Circulating tumor cells (CTC) are individual cells or clusters that can move from tumors to circulation invading other tissues. Often cells in the tumor need to adapt to low oxygen levels, generating a population of cells known as hypoxic cells that can survive low oxygen levels. These hypoxic cells can produce more cell junction proteins, augmenting connections between cells causing them to break away in clusters rather than individually. Clustered CTCs are much more efficient at metastasis formation. Release of CTC can also be stimulated by cancer treatments such as radiation and chemotherapy. To date, our research has generated in-vitro studies with a set of 3-nitrobenzazolo[3,2- a]quinolinium chloride salts (NBQS) demonstrating its capacity as markers of hypoxic human cancer cells in vitro. Comparison with the control Pimonidazole demonstrated the advantages of novel NBQ-TOM compounds as hypoxic marker. We here, aim to test the applicability of NBQS to identify hypoxic cells among circulating tumor cells (H-CTC). To date limited commercially CTC detection methods are available. Our application can be described as pre-clinical detection technology of hypoxic cancer cells serving also in cancer management. To determine the capacity of novel compound, NBQ-345 TOM as hypoxic fluorescent marker, colon tumor cells (COLO 205) are culture under hypoxic and aerobic environment and treated with NBQ-345TOM (25uM) for 24 hours. After treatment fluorescence is measured with an OPTIMA BMG Fluorimeter. Fluorescence emission results demonstrated significant formation of the NBQ-234 TOM fluorescent metabolite on hypoxic tumor cells in contrast to cells treated under aerobic environment. Also, fluorescence microscopy analysis of colon cancer cells treated for 24 hours with NBQ-345 TOM at hypoxic and aerobic conditions confirmed the stronger fluorescence generation at hypoxic conditions in contrast to cells at aerobic conditions.
Citation Format: Beatriz Zayas, Karoline Rios, Luis Ortiz, Osvaldo Cox. Markers of hypoxic cells: Testing a pre-clinical detection assay. [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 5602.
Abstract 5671: MB201, a CD8+ T cell-selective anti-PD-L1 x IL-2 variant fusion protein, exhibits a potent anti-tumor efficacy without peripheral toxicity
Authors: Park Bom , Bang Hyojoo , Jung Youngjun , Cho Sunjung , Kim Mi Seong , Kang Seok Chan , Jung Sungyoub , Park Youngjin 
Published: June 2023

Abstract
Interleukin-2 (IL-2), a cytokine with pleiotropic immune effects, is the first approved cancer immunotherapy. However, the clinical application of IL-2 is limited by systemic activation of unexpected immune cells, leading to severe toxicities including vascular leakage syndrome (VLS). These adverse effects were mainly caused by the activation of Treg and endothelial cells bearing IL-2 receptor (IL-2R) αβγ. Recently, studies have mainly focused on the optimization of IL-2Rs binding affinity to selectively invigorate CD8+ T cells in tumors, but the toxicity risk has yet to be solved. To overcome these limitations, we developed MB201, a novel anti-PD-L1 x IL-2v fusion protein, which selectively activates CD8+ T cells by attenuating binding affinity to IL-2Rβγ with no binding to IL-2Rα.
MB201 showed a strong binding affinity to PD-L1 (KD value is 0.5 nM) and a weak binding affinity to IL-2Rβγ and IL-2Rαβγ (KD value is 23.8 nM and 30.6 nM, respectively), indicating the preferential targeting PD-L1+ tumor cells. MB201 exhibited a preferential activation of CD8+ T cells than Treg cells, which showed remarkably reduced activation compared to rhIL-2 (more than 100-fold based on EC50). Consistently with the result of T cell activation, MB201 only increased the expansion of CD8+ T cells rather than Treg cells in CD3-stimulated PBMC. Indeed, MB201 induced negligible expansion of immune cells and lower pro-inflammatory cytokine release compared to the rhIL-2 in CD3-unstimulated PBMC, indicating the reduced peripheral toxicity risk. When administered to MC38 syngeneic mice, MB201 showed superior anti-tumor efficacy without both body weight reduction and lung weight gain compared to the avelumab monotherapy or combination therapy with rhIL-2. These preclinical observations support that MB201 has characteristics of a superb safety profile and excellent anti-tumor efficacy, and it may offer an advantageous therapeutic strategy for the treatment of cancer.
Citation Format: Bom Park, Hyojoo Bang, Youngjun Jung, Sunjung Cho, Mi Seong Kim, Seok Chan Kang, Sungyoub Jung, Youngjin Park. MB201, a CD8+ T cell-selective anti-PD-L1 x IL-2 variant fusion protein, exhibits a potent anti-tumor efficacy without peripheral toxicity. [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 5671.
Abstract 5823: Uncovering the mechanisms of matrix metalloproteinase-3 (MMP-3) in the cisplatin resistance of ovarian cancer
Authors: Rivera-Serrano Mariela , Vivas-Mejia Pablo E. 
Published: June 2023

Abstract
Seventy percent of women with ovarian cancer will develop chemotherapy-resistance to cisplatin. Regardless of the advancements in technology, mortality rates for ovarian cancer have declined only slightly in the last forty years, reiterating the need to generate novel treatment options targeting cisplatin resistance. In RNA-seq and microarrays experiments we observed that Matrix-metalloproteinase-3 (MMP3) was highly abundant in cisplatin-resistant when compared to cisplatin-sensitive cells. MMP3 is a member of the matrix metalloproteinases (MMPs) family of proteolytic enzymes, involved in the degradation of proteins in the extracellular matrix (ECM). Deregulation of MMPs alters the extracellular matrix and contributes to proliferation, invasion, and metastasis of cancerous cells. A typical MMP structure consists of a pro-domain, a catalytic, and a hemopexin domain. The catalytic domain is responsible for MMPs proteolytic activity, while the hemopexin domain contributes to substrate and ligand specificity. Inhibitors targeting the catalytic domain of MMPs were unsuccessful in clinical trials due to a lack of selectivity and specificity. When we used a chemical inhibitor, we did not observe reduced cell-proliferation or invasiveness. However, MMP3-targeted small interference RNA (siRNA) was able to reduce cell proliferation and invasive capabilities in cisplatin resistant ovarian cancer cells. Additionally, MMP3-targeted siRNA significantly reduced the sensitivity of ovarian cancer cells to cisplatin treatment. Cisplatin also increased MMP3 mRNA levels in ovarian cancer mice models and human cell lines. This evidence suggests that the MMP3 levels correlate with the sensitivity of ovarian cancer cells to cisplatin treatment. We hypothesize that the hemopexin domain will bind to proteins promoting cisplatin-resistance. We validated our expression profile studies at mRNA and protein levels via western blot, ELISA and qRT-PCR. Additionally, survival analysis using the Kaplan-Meier plotter database showed that ovarian cancer patients with low MMP3 levels live longer than patients with higher MMP3 levels. Furthermore, when we measured MMP3 activity, we observed decreased activity in cisplatin-resistant versus cisplatin-sensitive cells. Taken together, these data suggest that other domains of MMP3 (i.e., hemopexin domain) may have a function in the cisplatin resistance of ovarian cancer cells.
Citation Format: Mariela Rivera-Serrano, Pablo E. Vivas-Mejia. Uncovering the mechanisms of matrix metalloproteinase-3 (MMP-3) in the cisplatin resistance of ovarian 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 5823.
Abstract 5825: TM4SF19 regulates oxidative stress-dependent YAP transcription in HNSCC
Authors: Shin Eunbie , Kim Joon 
Published: June 2023

Abstract
Head-and-neck squamous cell carcinoma (HNSCC), which arises from epithelial cells in mucosal surfaces of the upper aerodigestive tract, is the sixth leading cancer worldwide with 40-50% mortality rates. YAP is a transcriptional regulator that plays important roles in cancer cell proliferation and survival. HNSCC shows the highest levels of YAP gene expression among various types of human cancers. However, the molecular mechanisms explaining upregulation of YAP expression in HNSCC are poorly understood. Excessive consumption of tobacco and alcohol are classical risk factors of HNSCC. Tobacco and alcohol generates metabolites that increase reactive oxygen species (ROS) to abnormally high levels. It is not known whether YAP expression and function are interlinked with the oxidative stress response in HNSCC. Here, we aimed to elucidate the mechanism of YAP upregulation involved in the progression of HNSCC under conditions of oxidative stress. To identify candidates for YAP expression regulators in HNSCC, we analyzed whole-genome siRNA library screening data and TCGA genomics data. We performed loss-of-function and gain-of-function experiments to elucidate the molecular mechanism of TM4SF19, which is the top candidate for mediating transcriptional regulation of YAP in HNSCC. TM4SF19 is one of the transmembrane 4 L six family proteins that have topological similarities to tetraspanins, but little is known about its biological function. We found TM4SF19 controls the expression of YAP gene by regulating GABPβ1, a subunit of the GABP transcription factor complex, which is known to bind and activate YAP gene promoter. We observed that the depletion of TM4SF19 reduced GAPBPβ1, thereby decreasing the transcriptional activity of GABP complex. Importantly, we observed that TM4SF19 was dimerized in response to oxidative stress and consequently mediates the upregulation of YAP transcription by ROS elevation. We further show that TM4SF19 knockdown significantly reduces key characteristics of malignant cells, such as active proliferation and migration. Our results suggest that TM4SF19 is not only a novel transcriptional regulator of YAP but also a strong therapeutic target to suppress the oncogenic activity of YAP, and also provide new clue to understand HNSCC tumorigenesis involving YAP and oxidative stress.
Citation Format: Eunbie Shin, Joon Kim. TM4SF19 regulates oxidative stress-dependent YAP transcription in HNSCC. [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 5825.
Abstract 6296: Preclinical study of a novel anti-CLEC12A antibody-drug conjugate with a glucuronide-protected pyrrolobenzodiazepine payload
Authors: Jung Jinwon , Kim Juhee , Lee Bora , Kwon Jung A , Lee Suyoun , Yoo Byeongmin , Ko Minji , Ryu Ilhwan , Yeom Donghoon , Lee Kyoungjae , Eom Jaehyun , Lee Hanbyul , Ahn Jinhyung , Sung Eunsil , You Weonkyoo , Lee Sang Hoon , Kim Myeong Joo , Kwon Keon Woo , Bae Hyun Joo , Park Yun-Hee , Song Ho Young , Chung Chul-Woong 
Published: June 2023

Abstract
C-type lectin domain family 12 member A (CLEC12A, CLL-1) is a single-pass transmembrane protein of 265 amino acids that is found on monocytes and AML blasts. We have created and characterized antibody-drug conjugates (ADCs) based on a humanized CLEC12A specific antibody to determine whether CLEC12A may be exploited as a therapeutic target for AML. The payload is a proprietary PBD prodrug with a beta-glucuronide trigger, and the linker-payload was conjugated through farnesyltransferase-mediated functionalization. The ADC demonstrated sub-nM cytotoxicity in vitro against several CLEC12A-positive cell lines including HL-60 and PL21. Leu234Ala/Leu235Ala (LALA) mutations were employed to reduce Fc gamma receptor binding and to avoid on-target toxicity. The LALA mutation-bearing ADC displayed a nearly 50-fold decrease in cytotoxicity towards CD34+ hematopoietic stem cells. Its potency was reduced but still sufficient with IC50 values of 61 pM and 15 pM against HL60 and PL21, respectively. Regardless of LALA mutation, the ADCs demonstrated potent antitumor activities with a complete regression at a dose of 0.5 mpk against a subcutaneous HL-60 SCID mouse xenograft model. When the LALA-mutated ADC was tested against a disseminated NSGA mouse model of HL-60-luc, all treated animals survived without clinical symptoms for three weeks after treatment, whereas vehicle-treated animals exhibited morbidity 19 days after treatment or 35 days after tumor implantation. The bone marrow of ADC-treated animals appeared to have nearly fully recovered, whereas that of vehicle-treated animals showed necrosis or tumor growth. In cynomolgus monkeys, the LALA-mutated ADC had a half-life of 82 hours at a dose of 0.2 mpk, and target-mediated drug disposition appeared weak or negligible. Our preclinical studies have shown that CLEC12A targeting ADC can be used as a therapeutics for treating AML.
Citation Format: Jinwon Jung, Juhee Kim, Bora Lee, Jung A Kwon, Suyoun Lee, Byeongmin Yoo, Minji Ko, Ilhwan Ryu, Donghoon Yeom, Kyoungjae Lee, Jaehyun Eom, Hanbyul Lee, Jinhyung Ahn, Eunsil Sung, Weonkyoo You, Sang Hoon Lee, Myeong Joo Kim, Keon Woo Kwon, Hyun Joo Bae, Yun-Hee Park, Ho Young Song, Chul-Woong Chung. Preclinical study of a novel anti-CLEC12A antibody-drug conjugate with a glucuronide-protected pyrrolobenzodiazepine payload [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 6296.