bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2372: Does the ubiquitin E3 ligase glycoprotein 78 (gp78/amfr) link socioeconomic factors, race, and biology in breast cancer?
Authors: Ellis Myles A.
Published: April 2023

This year there will be 260,00 new cases of breast cancer in the United States. Close to 40,000 women living with breast cancer, will die from the disease by the years end. However, these statistics are not evenly distributed across our citizens. Women of Western African descent are 40% more likely to die from breast cancer than their European counterparts.  Although socioeconomic factors along with racism, including affordable quality health care, availability of healthy foods, wage gaps, and trustworthiness of our physicians, have a considerable role in the difference in survival, there still is a significant gap in our understanding of the contribution of biology.  Therefore, biomarkers, mechanisms, and pathways connected with more aggressive biology that differ by race and genetic ancestry must be examined.  The ubiquitin E3 ligase, glycoprotein 78 (GP78/AMFR) is an endoplasmic reticulum-resident protein that degrades unfolded proteins found in the cell. It also supports lipid synthesis, autophagy and targets certain proteins that cause endoplasmic reticulum stress that could result in apoptosis. We have found that GP78 is a functional biomarker for breast cancer in women. Higher levels of this gp78, detected by validated antibody, is associated with more aggressive subtypes of breast cancer (e.g., luminal B, HER2 and triple-negative breast cancer, TNBC) and is expressed at notably elevated levels in breast cancer compared to normal glands. In addition, its expression is associated with poor survival, regardless of subtype, specifically in women of Western African descent. In vivo experiments using murine syngeneic allograft models, comparing wild type and gp78 knock breast cancer cells show the gp78 is required for tumor growth. Further analysis reveals a role for gp78 lipogenesis linked to immune suppression in the tumor microenvironment. Conclusion: These observations suggest a role for gp78 in 1) tumor growth and 2) immune suppression, and implies a role for race and genetic ancestry in the association between gp78 and breast cancer survival.  Therefore, corroborating a role for gp78 in both tumor growth and suppression of the tumor immune microenvironment will be an important future goal. We will validate and extend these findings in additional diverse patient populations to define the association between GP78, patient tumor biology, clinical feature, patient exposures, and other social determinants of health. 

Citation Format: Myles A. Ellis. Does the ubiquitin E3 ligase glycoprotein 78 (gp78/amfr) link socioeconomic factors, race, and biology in breast cancer?   [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2372.
Abstract 2431: The role and regulation of YAP1 in paligenosis, the cell program converting mature cells into precancerous metaplasia
Authors: Zeng Yongji , Willet Spencer G. , Huang Yangzhe , Bark Steven , Mills Jason C.
Published: April 2023

To advance gastric cancer prevention, diagnosis, and treatment, and understand its origins, we aim to understand why precursor metaplasias form and how they progress to cancer. Paligenosis is a recently characterized conserved molecular process which cells use to convert from normal, differentiated, mature cells into proliferative, progenitor-type cells; in the stomach, paligenosis converts digestive-enzyme-secreting chief cells into Spasmolytic Polypeptide Expressing Metaplasia cells (SPEM). Paligenosis occurs by stepwise series of cellular-molecular events characterized by dynamic regulation of mTORC1: Stage 1, mTORC1 decreases, chief cells scale down their secretory apparatus. Stage 2, SPEM genes are induced. Stage 3, mTORc1 increases and the previously mitotically quiescent cells re-enter the cell cycle. Unregulated or “unlicensed” paligenosis imparts nondividing mature differentiated cells the ability to re-enter the cell cycle despite mutations and other genomic abnormalities, making paligenosis a likely initiating process for gastric cancer. The Hippo pathway regulates cell proliferation and differentiation by phosphorylating the transcriptional co-activator YAP1. YAP1 can also act as an oncogene during tumorigenesis, but the regulation of the Hippo pathway and YAP1 in metaplasia and in paligenosis are still unclear. Here we show that YAP1 accumulates in Stage 2 leading to increased expression of many canonical transcriptional targets including cell cycle genes. Overexpression of YAP-S127A in low-dose-tamoxifen-treated Mist1CreERT2/+; ROSA26LSL-rtTA.IRES.EGFP/+; tetOYap1S127A mice induced by doxycycline is sufficient to induce chief cells to enter mitosis while the deletion of YAP1 in Mist1CreERT2/+; ROSA26LSL-Ai9/+; YAP1flox/flox ; TAZflox/flox mice leads to the failure of chief cells to go through paligenosis. Yap1 mRNA was changed by single-cell RNA sequencing, whereas proteomics with western blot validation showed unchanged total YAP1 protein, suggesting YAP1 may be regulated by subcellular localization. Multi-omic data with western blot and immunohistochemistry validation indicated YAP1 localization is regulated in a Hippo pathway kinase-dependent way and SMAD2/3, key effectors of TGF-β signaling, being potential downstream targets. In summary, our study indicates that YAP1 activity is required for paligenosis, working independently of Hippo and interacting with TGF-β signaling.

Citation Format: Yongji Zeng, Spencer G. Willet, Yangzhe Huang, Steven Bark, Jason C. Mills. The role and regulation of YAP1 in paligenosis, the cell program converting mature cells into precancerous metaplasia [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 2431.
Abstract 2446: An investigation of HOX-regulatory mechanisms and their role in the SC origin of human CRC
Authors: Osmond Brian , Facey Caroline O. , Opdenaker Lynn M. , Zhang Chi , Boman Bruce M.
Published: April 2023

HOX genes are a highly conserved subset of genes that encode for transcription factors critical for stem cell (SC) function and embryonic development. Several HOX genes have also been implicated in a myriad of cancers, including colorectal cancer (CRC). However, the mechanisms by which HOX genes contribute to cancer development are still not fully understood. Specifically, the mechanisms by which HOX genes regulate SC populations and how SC dysregulation leads to tumorigenesis needs to be clarified. Current research indicates that HOX genes are regulated by WNT and retinoic acid (RA) signaling.

Goal: To ascertain how HOX-regulatory mechanisms play a role in the SC origin of human CRC.

Hypotheses: (1) HOX genes regulated by RA and WNT signaling control SC differentiation along various lineages in normal human colonic epithelium. (2) Aberrant expression of HOX genes leads to decreased differentiation and CSC overpopulation in CRC. Preliminary data shows that RA signaling occurs in ALDH+ SCs and HOXA4, HOXA9 & HOXD10 are selectively expressed in ALDH+ SCs. Moreover, treatment of CRC cells with all-trans retinoic acid (ATRA) modulates expression of HOXA4, HOXA9, HOXC8, HOXC9, & HOXD10 while also reducing cell count. Nanostring profiling also shows that expression of select HOX genes (HOXA3, HOXA4, HOXA5, HOXA10, HOXB6, HOXB8, HOXB9, & HOXD9) significantly changes in response to ATRA. Bioinformatics analysis has identified RA response elements (RAREs) within the promoters of all mentioned HOX genes. Understanding how HOX genes control normal colonic SCs, and, how they become dysregulated in CSCs will identify mechanisms that help explain how HOX genes contribute to SC overpopulation that drives colorectal cancer (CRC) growth.

Citation Format: Brian Osmond, Caroline O. Facey, Lynn M. Opdenaker, Chi Zhang, Bruce M. Boman. An investigation of HOX-regulatory mechanisms and their role in the SC origin of human CRC [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 2446.
Abstract 2448: Galectin-3 regulates stemness and cellular states in glioblastoma stem cells
Authors: Akosman Bedia , Lalvani Shaan , Suita Yusuke , Karambizi David , Tapinos Nikos
Published: April 2023

Glioblastoma stem cells (GSCs) are a subset of cells in the Glioblastoma (GBM) tumor microenvironment that play an important role in tumor heterogeneity, aggressiveness, recurrence, and therapy resistance. Dynamic environmental, transcriptional, and epigenetic oscillations envelope GSCs in a variety of cellular states, contributing to GSC heterogeneity and carcinogenesis. The creation of effective therapies may therefore benefit from a better understanding of the factors associated with the GSC's distinct traits as well as the mechanisms affecting GSC cellular states and transformation.

Galectin-3 is a molecule that is highly expressed in GBM, and higher levels are linked to poor survival and mesenchymal subtype. Although Galectin-3 has previously been found primarily in microglia and tumor-infiltrating macrophages, our studies using patient-derived GSCs show that it is abundantly produced by GSCs and that its expression significantly decreases when they differentiate into non-stem differentiated cancer cells, which are more responsive to therapies. Our findings also show that Galectin-3 is not expressed in normal neural stem cells, leading us to believe that it could serve as a unique identifier for GSCs. Additionally, when Galectin-3 is silenced in GSCs, we see a decreased self-renewal frequency and enrichment of genes associated with pro-neural state, which has a less aggressive phenotype. Confocal imaging and single-cell RNA-seq analysis further revealed heterogeneous expression of Galectin-3 in GSCs, and the functional pathway analysis shows that Galectin-3high cell clusters have a significant overlap with cells enriched in EMT pathways. Therefore, our findings suggest that Galectin-3 may be a unique distinguishing characteristic of GSCs and may play a particular role in regulating GSC stemness and determining GSCs states, making it a potential molecular target for the treatment of glioblastoma.

Citation Format: Bedia Akosman, Shaan Lalvani, Yusuke Suita, David Karambizi, Nikos Tapinos. Galectin-3 regulates stemness and cellular states in glioblastoma stem cells [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 2448.
Abstract 2453: Olfactomedin 4 downregulation enhances MYC-signaling in human benign prostate cells and the Olfm4 mouse models
Authors: Li Hongzhen , Liu Wenli , Zhu Jianqiong , Chin Kay , Rodgers Griffin P.
Published: April 2023

Prostate cancer is the most diagnosed solid tumor and the second leading cause of cancer related death in American men. We have reported previously that OLFM4 gene expression was reduced or lost during prostate cancer progression due to frequent genetic deletion and hypermethylation of the OLFM4 gene promoter region. To investigate OLFM4 gene biological functions and molecular mechanisms underlying prostate cancer progression, we have established OLFM4 knock out RWPE1 cells and Olfm4 knock out mouse model. Functionally, OLFM4-knockout RWPE1 cells exhibited enhanced proliferation of the stem/progenitor-like cell population and abnormal differentiation. Bulk-cell RNA sequencing analysis pinpointed that MYC expression was enhanced in the OLFM4-knockout RWPE1 cells compared with OLFM4-wild cells. Molecular and signaling pathway studies revealed an increase in the WNT/APC/MYC signaling pathway gene signature and MYC target genes that regulate multiple biological processes in OLFM4-knockout RWPE1 cells and Olfm4-knock out mouse models. To test the function of the MYC gene in RWPE1 cells, we used (+)-JQ1, an MYC inhibitor, in both 2D and 3D culture models and found that (+)-JQ1 substantially inhibited the proliferation of OLFM4-knockout GFP reporter RWPE1 cells compared with OLFM4-W RWPE1 cells in both types of cultures. We further studied MYC inhibitors using organoid culture for Olfm4-/-/TRAMP mouse prostate tumors. These results suggest that OLFM4-negative prostate cancer is more sensitive to MYC inhibitor’s therapeutic approaches.

Citation Format: Hongzhen Li, Wenli Liu, Jianqiong Zhu, Kay Chin, Griffin P. Rodgers. Olfactomedin 4 downregulation enhances MYC-signaling in human benign prostate cells and the Olfm4 mouse 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 2453.
Abstract 2612: Mutational pattern of SWI/SNF pathway genes in lung adenocarcinoma patients reveal uneven correlation with immunotherapy sensitivity
Authors: Tang Haimeng , Bao Hua , Wu Xue , Shao Yang
Published: April 2023

Background: The search for prognostic biomarkers indicating sensitivity to immunotherapy in lung adenocarcinoma patients have zeroed in on genes in the SWI/SNF pathway. However, the mutational profiles of the relevant key genes on this pathway have not been clearly defined, and no comparisons have been conducted on whether mutations in these genes provide the same predictive value in lung cancer patients.

Methods: In this study, statistical analysis of clinical factors, tumor mutation burden, chromosomal instability, and co-appearing alterations of 5 key genes on the SWI/SNF pathway was conducted for 4344 lung adenocarcinoma samples. Two independent online cohorts (N = 1661 and N = 576) were used to supplement the analysis with survival and RNA-Seq data, respectively.

Results: ARID mutations were found to be more prominent in males under the age of 60 than any other clinical group, while no significant differences exists for SMARC-mutant groups. Mutational burden and chromosomal instability analysis showed that patients with either ARID family mutations (including ARID1A, ARID1B, or ARID2 mutations) or SMARC family mutations (including SMARCA4 or SMARCB1 mutations) display different sample-level metrics than patients with wild-type samples (TMB: ARID v WT: p<2.2X10-16, SMARC v WT: p<2.2X10-16; CIN: ARID v WT: p=1.8X10-5, SMARC v WT: p=0.027). Additionally, both mutant groups have a higher proportion of transversions than transitions, while the ratio is more equal for wild-type samples. Survival analysis shows that patients with ARID mutations were more sensitive to immunotherapy treatment than wild-type and SMARC-mutated patients (p < 0.001 and

p=0.013, respectively), and multivariate cox analysis reveals that presence of ARID mutations is likely the main cause. Furthermore, we observed higher expression of genes on the MTOR1C signaling pathway and the unfolded protein response pathway in the SMARC-mutated group in comparison to the ARID-mutated group, both of which have been reported to increase resistance to immunotherapy.

Conclusions: In summary, the mutational landscape of 5 major SWI/SNF pathway genes were classified. The research presented also shows that mutations in the ARID gene family, including ARID1A, ARID1B, and ARID2, are primarily responsible for the sensitive response to immunotherapy treatment in patients with SWI/SNF mutant lung adenocarcinoma.

Citation Format: Haimeng Tang, Hua Bao, Xue Wu, Yang Shao. Mutational pattern of SWI/SNF pathway genes in lung adenocarcinoma patients reveal uneven correlation with immunotherapy sensitivity [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 2612.
Abstract 2617: Rac and Cdc42 inhibition on macrophage function in the pancreatic tumor microenvironment
Authors: Torres-Sánchez Anamaris , Rivera-Robles Michael , Dorta-Estremera Stephanie , Dharmawardhane Suranganie
Published: April 2023

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal forms of cancer. To date, there are few therapies that are efficient against this disease, and patients often develop therapy resistance. The homologous Rho GTPases, Rac and Cdc42, are overexpressed in pancreatic cancer and correlated with poor prognosis. Rho GTPases regulate cell migration/invasion, cell morphology/polarity, and cell survival/viability. Rac and Cdc42 are essential Rho GTPases in oncogenic transformation and invasiveness and govern invasion in both cancer cells and tumor-associated macrophages (TAMs). TAMs are immunosuppressive cells that exacerbate cancer progression via inflammatory responses and crosstalk signaling with malignant cancer cells to promote invasion and immunesuppression. Our laboratory has developed a dual Rac/Cdc42 inhibitor, MBQ-167 (IC50 100nM), as an anticancer agent that recently received IND approval from the US FDA due to its safety and efficacy in breast cancer models. The hypothesis tested in this study is that MBQ-167 will simultaneously target the migration and activity of pancreatic cancer cells and immunosuppressive cells in the tumor microenvironment (TME). To evaluate this, we performed pulldown assays for Rac and Cdc42 activation, MTT cell viability assays, wound-healing assays for cell migration, and phagocytosis assays using human and rat macrophage and human pancreatic cancer cell lines. Results show that MBQ-167 is not toxic to macrophages even at concentrations as high as 10uM. MBQ-167 inhibited Rac1activation by 75% and Cdc42 activation by 40% in THP-1 human macrophages at 500nM. MBQ-167 reduced macrophage migration by 67% at 150nM, and decreased pancreatic cancer cell migration by 60% at 250nM. In addition, MBQ-167 reduced macrophage phagocytosis by 56% at 500nM. This study demonstrates the utility of Rac/Cdc42 inhibition to reduce pancreatic cancer progression in the TME.

Citation Format: Anamaris Torres-Sánchez, Michael Rivera-Robles, Stephanie Dorta-Estremera, Suranganie Dharmawardhane. Rac and Cdc42 inhibition on macrophage function in the pancreatic tumor microenvironment [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 2617.
Abstract 2723: Treatment of gastric cancer cells with tumor treating fields (TTFields) and concomitant FOLFOX
Authors: Flint-Brodsly Naama , Zeevi Einav , Wainer-Katsir Kerem , Fishman Hila , Martinez-Conde Antonia , Dor-On Eyal , Munster Mijal , Porat Yaara , Voloshin Tali , Davidi Shiri , Haber Adi , Giladi Moshe , Weinberg Uri , Palti Yoram
Published: April 2023

Background: Gastric cancer, one of the most common types of cancers, is mainly treated with the FOLFOX chemotherapy regimen (oxaliplatin, fluorouracil [5-FU], and leucovorin); yet long-term survival remains poor. Tumor Treating Fields (TTFields) are electrical fields that disrupt cellular processes critical for cancer cell viability and tumor progression, ultimately leading to cell death. In several tumor types, the mechanism of action of TTFields included an antimitotic effect and DNA damage induction with impaired DNA damage repair. The current study aimed to examine the efficacy of TTFields for treating gastric cancer cells, and the potential application of TTFields concomitant with FOLFOX.

Methods: Human gastric cancer cell lines, AGS and KATO III, were treated with TTFields (intensity of 1.1 and 1.7 V/cm, respectively; frequency of 150 kHz) using the inovitro system. Cell count and colony formation were examined following treatment, and the overall effect calculated by multiplication of the two. RNA sequencing was also performed on samples from control and TTFields-treated cells. Mitotic spindle defects, chromosome miss-localization, and DNA double strand breaks (DSB) formation were examined by fluorescent staining for α-tubulin, phospho-histone 3 (PH3), and phospho-histone H2AX (γH2AX), respectively. Expression of DNA repair proteins was measured using Western Blot. The impact of TTFields with FOLFOX and its individual therapeutic components, oxaliplatin and 5-FU on cell count and clonogenicity was tested.

Results: TTFields reduced cell count and the colony forming ability of the cells. Cells treated with TTFields displayed abnormal mitotic figures and increased levels of DNA damage. Expression of DNA repair proteins was downregulated following treatment with TTFields, as evident from RNA and protein levels. Furthermore, TTFields augmented the cytotoxic and clonogenic effects of FOLFOX and its individual therapeutic components, oxaliplatin and 5-FU.

Conclusions: TTFields show potential as an effective gastric cancer treatment, with a mechanism of action involving an anti-mitotic effect and DNA damage repair impairment. TTFields may be applied to enhance the efficacy of gastric cancer standard-of-care.

Citation Format: Naama Flint-Brodsly, Einav Zeevi, Kerem Wainer-Katsir, Hila Fishman, Antonia Martinez-Conde, Eyal Dor-On, Mijal Munster, Yaara Porat, Tali Voloshin, Shiri Davidi, Adi Haber, Moshe Giladi, Uri Weinberg, Yoram Palti. Treatment of gastric cancer cells with tumor treating fields (TTFields) and concomitant FOLFOX [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 2723.
Abstract 273: Synergistically suppressive effects by combination of glycolytic inhibitor with TRAP1-depletion in colorectal cancer
Authors: Tsai Hong-Yuan , Chen Miao-Hsueh , Senavirathna Herath Lakmini , Yun Jihye , Pan Sheng , Chen Ru
Published: April 2023

Tumor necrosis factor receptor-associated protein 1 (TRAP1) is a mitochondrial homolog of HSP90 chaperones. It plays an important role in protection against oxidative stress and apoptosis by regulating reactive oxidative species (ROS). Recent studies have suggested TRAP1 as a regulator of metabolism and mitochondrial homeostasis in diverse pathological states, including cancer. To further elucidate the mechanistic role of TRAP1 in regulating tumor cell survival, we used gamitrinib-triphenylphosphonium (G-TPP) to inhibit TRAP1 signaling pathways in colon cancer. Inhibition of TRAP1 disrupted redox homeostasis and increased ER stress in colon cancer. To confirm the G-TPP effects of TRAP1 inhibition in colon cancer, we performed TRAP1 CRISPR/Cas9 to deplete TRAP1 expression in colon cancer cell line CT26. TRAP1-depleted cells were found to acquire several distinct phenotypes: induction of reactive oxidative species (ROS) level, reduction of cell growth, and lower pH value of culture medium. In addition, proteomic data showed that depletion of TRAP1 induced significant metabolism alteration in CT26 cells. Using seahorse assay to access mitochondrial respiration and glycolysis, we found that TRAP1-depleted cells were insensitive to Oxidative Phosphorylation (OXPHOS) inhibitor treatment and significantly increased extracellular acidification rate (ECAR) compared to parental cells. Furthermore, higher glucose consumption rate and higher lactic acid level of culture medium were observed in TRAP1-depleted cells. On the other hand, Glycolytic inhibitor (2DG) led to excessive ROS production, reduction of glucose uptake and exacerbated cell death in TRAP1-depleted cell compared to parental cells. Taken together, depletion of TRAP1 induces mitochondrial dysfunction and modulates metabolic switch toward aerobic glycolysis in TRAP1-depleted colon cancer cells. Dual inhibition of TRAP1 and glycolytic signaling may increase therapeutic efficiency through induction of excessive ROS production in colon cancer.

Citation Format: Hong-Yuan Tsai, Miao-Hsueh Chen, Herath Lakmini Senavirathna, Jihye Yun, Sheng Pan, Ru Chen. Synergistically suppressive effects by combination of glycolytic inhibitor with TRAP1-depletion in colorectal 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 273.
Abstract 3029: Barriers to optimal breast cancer screening modalities for high-risk patients in the primary care setting
Authors: Jan Yu Jen , Lam Prudence B.
Published: April 2023

Background: Annual screening breast MRIs are endorsed by current breast cancer screening guidelines as an adjunctive screening modality for high-risk patients (defined by more than 20% lifetime risk) in addition to a screening mammogram. Recent studies showed screening breast MRI remained underutilized despite the current recommendations. On the other hand, validated breast cancer risk models for identifying high-risk patients also remained under-recognized among primary care providers. This study aims to identify the potential barriers for primary care providers (PCPs) to using breast cancer risk models and referring high-risk patients to breast MRI for screening.

Methods: An anonymous survey was distributed via email to the PCPs and OB/GYN providers in the network of Mount Auburn Hospital, a community teaching hospital affiliated with Harvard Medical School in Cambridge, Massachusetts. The survey included questions regarding breast cancer screening in average-risk and high-risk patients, providers’ understanding of breast cancer risk models, and current referral status of breast MRIs and high-risk/genetic clinics.

Results: The survey was sent to 104 providers, and 43 responses were received. When asked about performing breast cancer risk assessments, 58% reported “Always (91-100%)” and 33% said “Often (71-90%)”. For factors to consider when performing risk assessments, most of the providers considered personal medical history (98%), family history (100%), genetic syndrome history (86%), and previous breast biopsy results (90%). When asked about breast cancer risk models, 58% of the providers had not heard of or used one. 33% of the providers have used the Gail model, and 26% have used the Tyrer-Cuzick model. 51% of the providers correctly identified high-risk as lifetime risk >20%. 56% correctly answered annual mammograms with MRI for breast cancer screening for high-risk patients. The majority of the providers (84%) would prefer to refer patients to the high-risk clinic for risk assessment and screening management. For barriers to referring to MRI, the insurance approval process (49%) was reported to be the largest barrier. 72% of the providers prefer not ordering it and defer to the high-risk/genetic clinic for ordering the test.

Conclusions: Our survey has shown different barriers to breast cancer screening in high-risk patients in the primary care setting, including knowledge and logistic barriers. Further education for PCPs is needed for correctly identifying high-risk patients, utilizing risk models, and referring high-risk patients for breast MRI screening.

Citation Format: Yu Jen Jan, Prudence B. Lam. Barriers to optimal breast cancer screening modalities for high-risk patients in the primary care setting [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 3029.
Abstract 315: HPV-related genome rearrangements in head and neck cancer cell lines
Authors: Mukhina Vera , Anderson Alexa , Gaykalova Daria A.
Published: April 2023

Cancer-associated papillomavirus (HPV) infection often leads to genomic rearrangements such as the integration of viral DNA into the human genome or formation of extrachromosomal DNA (ecDNA) circles with human-HPV DNA fusions, copy number alterations, translocations, inversions, or all at once. Such structures play a key role in cancer formation and progression by altering the expression of human and viral genes. They can also potentially increase genomic instability promoting new rearrangements, but little is known about how these rearrangements evolve during cancer. Unfortunately, short-read sequencing and standard assembly methods often fail to reconstruct HPV-induced rearrangements because of their repetitive nature. Long-read technology can potentially help to overcome this limitation.Here, we used Nanopore long-read whole genome sequencing to explore HPV structures in head and neck cancer cell line UPCI-SCC-090, known for its complex HPV rearrangements. We tested several protocols and methods on this cell line to estimate their impact on rearrangement detection. To study the dynamics of HPV rearrangements, we compared data from UPCI-SCC-090 to another cell line isolated later from the same patient (UPCI-SCC-152).As a result, we discovered a core set of UPCI-SCC-090 rearrangements involving chr 2,3,6 and 9, which remain robust across different tested protocols and methods, and these structures were consistent with previous studies. At the same time, we identified new minor rearrangements in UPCI-SCC-090 indicating heterogeneity within this cell line. The comparison with the UPCI-SCC-152 cell line demonstrated that most rearrangements were kept, but the overall profile of rearrangements changed. For example, UPCI-SCC-152 missed all HPV-induced alterations on chr 6.We concluded that the long-read approach failed to reconstruct all rearrangements completely but allowed us to study them in more detail on a single-molecule level and detect heterogeneity of HPV integrations within and between cell lines. We demonstrated that HPV-induced rearrangements formed a stable core that could persist for a long time with a minor group of variable rearrangements.

Citation Format: Vera Mukhina, Alexa Anderson, Daria A. Gaykalova. HPV-related genome rearrangements in head and neck cancer cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 315.
Abstract 3171: Detecting ploidy specific vulnerability to resource restriction: An integrated in vitro and in silico approach
Authors: Beck Richard J. , Ilter Didem , Gomes Ana P. , Andor Noemi
Published: April 2023

Changes in the number of copies of the genome, i.e. changes in ploidy are widespread among cancer cells. Increased ploidy is thought to benefit cancer cells by conferring robustness against deleterious consequences of genomic instability. However, whether there are any potential costs associated with increased ploidy has not been sufficiently investigated. One hypothesis holds that high ploidy cells may exhibit increased sensitivity to limitations in resources, due to the extra energy required for the replication of a larger genome. To address this hypothesis, we developed an integrated in vitro and in silico system to investigate the response to glucose restriction in diploid and tetraploid cells.

Near diploid (2N) SUM159 breast cancer cells were fused to generate an isogenic tetraploid (4N) cell line. 2N or 4N cells were plated with varying initial concentrations of glucose. Cells grew for five days and media was not refreshed, so cells depleted the glucose in the media until they eventually died. Throughout the experiments, glucose concentration was measured at 24 hour intervals, and images were taken at 8 hour intervals allowing quantification of the number of alive or dead cells over time. These in vitro data were then used as inputs to the in silico portion of our system, which consists of an Ordinary Differential Equation (ODE) model of cancer cell growth. ODE model parameters were estimated using the measured outputs from the in vitro experiments. Parameters estimated from the ODE model gave insight into differences between the 2N and 4N cell lines.

We found that 4N cells outcompeted 2N cells at high glucose concentrations, due to their ability to divide more rapidly when glucose was abundant. However, 2N cells were able to outcompete 4N cells at lower glucose concentrations. The advantage of 2N cells at low glucose was not due to an increased proliferative capacity. Instead, 2N cells were more resistant to cell death when glucose was limited. Our next steps will be to expand our system to assess ploidy specific sensitivity to other resources, such as phosphate or oxygen. The ODE model we have developed allows us to identify resource conditions that will select for tumor cells based on ploidy. In future this knowledge can be used to suggest therapeutics that can modulate resource availability within tumors, in order to steer tumor evolution towards less aggressive phenotypes.

Citation Format: Richard J. Beck, Didem Ilter, Ana P. Gomes, Noemi Andor. Detecting ploidy specific vulnerability to resource restriction: An integrated in vitro and in silico approach [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 3171.
Abstract 3285: Targeting TBK1 to overcome resistance to cancer immunotherapy
Authors: Sun Yi , Revach Or-Yam , Anderson Seth , Jenney Anne , Mills Caitlin E. , Tiwari Payal , Manguso Robert T. , Jenkins Russell William
Published: April 2023

Despite the success of PD-1 blockade in melanoma and other cancers, effective treatment strategies to overcome resistance to cancer immunotherapy are lacking. We identified the innate immune kinase TANK-binding kinase 1 (TBK1) as a candidate immune evasion gene in a pooled genetic screen. Using a suite of genetic and pharmacologic tools across multiple experimental model systems, we confirm a role for TBK1 as an immune evasion gene. Targeting TBK1 enhances response to PD-1 blockade by lowering the cytotoxicity threshold to effector cytokines (TNFα/IFNγ). TBK1 inhibition in combination with PD-1 blockade also demonstrated efficacy using patient-derived tumor models. Cancer cells lacking TBK1 are primed to undergo RIPK- and caspase-dependent cell death in response to TNFα/IFNγ in a JAK/STAT-dependent manner. Taken together, our results demonstrate that targeting TBK1 is a novel and effective strategy to overcome resistance to cancer immunotherapy.

Citation Format: Yi Sun, Or-Yam Revach, Seth Anderson, Anne Jenney, Caitlin E. Mills, Payal Tiwari, Robert T. Manguso, Russell William Jenkins. Targeting TBK1 to overcome resistance to cancer immunotherapy [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 3285.
Abstract 3287: A bedside to bench study of anti-PD-1, anti-CD40, and anti-CSF1R indicates that more is not necessarily better
Authors: Djureinovic Dijana , Weiss Sarah A. , Krykbaeva Irina , Qu Rihao , Vathiotis Ioannis , Moutafi Myrto , Zhang Lin , Perdigoto Ana L. , Wei Wei , Anderson Gail , Damsky William , Hurwitz Michael , Johnson Barbara , Mahajan Amit , Hsu Frank , Miller-Jensen Kathryn , Kluger Yuval , Sznol Mario , Kaech Susan M. , Bosenberg Marcus , Jilaveanu Lucia , Kluger Harriet M.
Published: April 2023

Stimulating innate immunity can potentially enable us to overcome resistance to PD-(L)1 blockade. We previously conducted a phase 1 trial of cabiralizumab (anti-CSF1R) with sotigalimab (CD40 agonistic antibody) and nivolumab. Our purpose was to determine safety and the effects of this regimen on circulating and tumor-infiltrating immune cells and to determine the activity of this regimen in a phase 1b trial for melanoma patients whose disease had progressed on anti-PD-(L)1. CyTOF analysis on circulating immune cells taken before and during treatment revealed a reduction in non-classical monocytes and an increase in dendritic cells. Patients with prolonged stable disease had less T-regulatory cells and more circulating antigen presenting cells after treatment compared to patients that were treated for a shorter time. In the phase 1b component of the trial in 13 melanoma patients, objective response rates were: 1 confirmed partial response (7.7%), 1 unconfirmed partial response (7.7%), 5 stable disease (38.5%) and 6 disease progression (42.6%). Despite therapy-induced changes in circulating immune cells and previous preclinical studies supporting rationale for this combination, responses in humans were insufficient to proceed to the second stage of the phase 1b trial. Given the challenges with translating doses from mice to humans, we proceeded to study various doses of anti-CSF1R in combination with CD40 agonist and anti-PD-1 in a murine model. Higher dose anti-CSF1R in mice was associated with increased tumor growth, worse survival and by single-cell RNA-sequencing analyses, we identified a more suppressive monocyte/macrophage profile in murine tumors. Our study suggests that more anti-CSF1R might not be better. Further optimization of cabiralizumab dosing is necessary to evaluate the clinical potential in combination with anti-PD-1 and anti-CD40 in a difficult-to treat patient population whose therapeutic options are limited.

Citation Format: Dijana Djureinovic, Sarah A. Weiss, Irina Krykbaeva, Rihao Qu, Ioannis Vathiotis, Myrto Moutafi, Lin Zhang, Ana L. Perdigoto, Wei Wei, Gail Anderson, William Damsky, Michael Hurwitz, Barbara Johnson, Amit Mahajan, Frank Hsu, Kathryn Miller-Jensen, Yuval Kluger, Mario Sznol, Susan M. Kaech, Marcus Bosenberg, Lucia Jilaveanu, Harriet M. Kluger. A bedside to bench study of anti-PD-1, anti-CD40, and anti-CSF1R indicates that more is not necessarily better [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 3287.
Abstract 3288: A novel and defined TLR3 agonist based anticancer therpay
Authors: Kim Dongho , Lee Sungwhan
Published: April 2023

Synthetic dsRNA analogs recognized by TLR3 are an attractive adjuvant candidate for fight against intracellular pathogens or tumors, because of their enhanced T cell-mediated and humoral immunities. Although poly(I:C) is a representative dsRNA with potent adjuvanticity, its clinical application has been severely limited due to heterogenicity, inconsistent activity, poor stability, and toxicity. In spite of numerous clinical trials, few products have been approved for human use. To overcome these limitations, we try to develop a novel defined form of TLR3 agonist. A single 275-kDa homogeneous molecule was selected as an alternative of poly IC and its derivatives and named NexaVant (NVT). The analytical analyses including reverse phase-HPLC analysis demonstrated that NVT is homologous without a lot-to-lot variation. NVT appears to be stable since its appearance, concentration, and molecular size were unaffected under 6 months of accelerated storage conditions. Moreover, preclinical evaluation of toxicity under good laboratory practices showed that NVT is a safe substance without signs of serious toxicity. NVT increases the expression of dsRNA sensors such as TLR3, MDA-5, and RIG-I. Together with a potent apoptotic cell death to several cancer cell lines, NVT substantially induced the phenotypic markers of DC maturation and activation including MHC-II, CD40, CD80, and CD86 together with IFN-alpha production. Several poly IC and its derivatives are used as a in situ anticancer agent in clinical trials. NexaVant was tested as an in-situ cancer therapy reagent in several animal models. When NVT is injected into tumors, it induces and recruits diverse immune cells with a potent anti-cancer effect. Combined with anit-PD-1 antibody, it shows the increase number of DC and T-cells, especially CD8 T cells and decrease that of Tregs. Using human PD-1 knock-in mouse model, NVT has shown the synergistic anti-cancer effect with anti-PD-1 antibody. Several animal efficacy data target to head and neck cancer, triple-negative breast cancer, and melanoma would be presented.

Citation Format: Dongho Kim, Sungwhan Lee. A novel and defined TLR3 agonist based anticancer therpay [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 3288.
Abstract 3302: KLK7 expression in human tumors: A tissue microarray study on 13,447 tumors
Authors: Kind Simon , Castillo Carolina , Uhlig Ria , Gorbokon Natalia , Lennartz Maximilian , Rico Sebastian Dwertmann , Reiswich Viktor , Viehweger Florian , Kluth Martina , Hube-Magg Claudia , Bernreuther Christian , Büscheck Franziska , Clauditz Till , Fraune Christroph , Hinsch Andrea , Krech Till , Lebok Patrick , Steurer Stefan , Burandt Eike , Minner Sarah , Marx Andreas , Simon Ronald , Wilczak Waldemar , Sauter Guido , Menz Anne , Jacobsen Frank
Published: April 2023

Background: Kallikrein-related peptidase 7 (KLK7) is a chymotrypsin-like serine protease which is essential for the desquamation of corneocytes and thus plays a pivotal role in maintaining skin homeostasis. In cancer, KLK7 overexpression was suggested to represent a route for metastasis through cleavage of cell junction and extracellular matrix proteins of cancer cells.

Methods: To comprehensively determine KLK7 protein expression in normal and neoplastic tissues, a tissue microarray containing 13,447 samples from 147 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry.

Results: KLK7 positivity was found in 64 of 147 tumor categories, including 17 tumor categories with at least one strongly positive case. The highest rate of KLK7 positivity was found in squamous cell carcinomas from various sites of origin (positive in 18.1%-63.8%), ovarian and endometrium cancers (4.8%-56.2%), salivary gland tumors (4.8%-13.7%), bilio-pancreatic adenocarcinomas (20.0%-40.4%), and adenocarcinomas of the upper gastrointestinal tract (3.3%-12.5%). KLK7 positivity was linked to nodal metastasis (p=0.0005), blood vessel infiltration (p=0.0037), and lymph vessel infiltration (p<0.0001) in colorectal adenocarcinoma, nodal metastasis in hepatocellular carcinoma (p=0.0382), advanced pathological tumor stage in papillary thyroid cancer (p=0.0132), and low grade of malignancy in a cohort of 719 squamous cell carcinomas from 11 different sites of origin (p<0.0001).

Conclusions: These data provide a comprehensive overview on KLK7 expression in normal and neoplastic human tissues. The prognostic relevance of KLK7 expression and the possible role of KLK7 as a drug target need to be further investigated.

Citation Format: Simon Kind, Carolina Castillo, Ria Uhlig, Natalia Gorbokon, Maximilian Lennartz, Sebastian Dwertmann Rico, Viktor Reiswich, Florian Viehweger, Martina Kluth, Claudia Hube-Magg, Christian Bernreuther, Franziska Büscheck, Till Clauditz, Christroph Fraune, Andrea Hinsch, Till Krech, Patrick Lebok, Stefan Steurer, Eike Burandt, Sarah Minner, Andreas Marx, Ronald Simon, Waldemar Wilczak, Guido Sauter, Anne Menz, Frank Jacobsen. KLK7 expression in human tumors: A tissue microarray study on 13,447 tumors [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 3302.
Abstract 3403: Leveraging a p53 “super-tumor suppressor” to understand mechanisms of lung adenocarcinoma regression
Authors: Wang Mengxiong , Kaiser Alyssa , Bieging-Rolett Kathryn , Brady Colleen , Attardi Laura
Published: April 2023

Lung cancer is the leading cause of cancer deaths worldwide, and lung adenocarcinoma (LUAD) comprises the majority of lung cancer cases. Inactivation of the TP53 tumor suppressor gene, which encodes the p53 transcription factor, is observed in ~50% of human LUADs and is associated with poor prognosis and therapeutic responses. Hence, pharmacological restoration of p53 is an appealing strategy for LUAD treatment. Previous studies have demonstrated that p53 reactivation in mouse LUAD models leads to tumor regression. Here, we seek to understand the molecular mechanisms through which p53 restoration promotes tumor regression. To this end, we sought to better understand the transcriptional programs underlying tumor regression by leveraging an allelic series of transcriptional activation domain (TAD) mutants. We generated mouse models of LUAD initiated by oncogenic Kras and loss of p53, followed by reactivation of wild-type p53 or p53 TAD mutants, including the TAD1 (p5325,26), TAD2 (p5353,54), and TAD1/2 (p5325,26,53,54) mutants. We find that restoration of wild-type p53 induces significant regression of established tumors. Interestingly, we find that restoration of the p5353,54 mutant induces tumor regression even more potently than wild-type p53, reminiscent of our previous findings showing this mutant is a “super” tumor suppressor in pancreatic cancer. In contrast, the transcriptionally-dead TAD1/2 mutant, p5325,26,53,54, is unable to drive tumor regression. To understand the basis of tumor suppression, we are currently analyzing antiproliferative cellular responses in tumors, including cell cycle arrest, apoptosis, autophagy and differentiation. We have also developed a complementary in vitro system to further explore the molecular mechanisms of p53 action in LUAD regression. RNA-sequencing analysis in this system has revealed transcriptional programs underlying the enhanced tumor regression with the p5353,54 mutant. Collectively, these findings have illuminated the individual contributions of each p53 TAD to LUAD regression. In particular, elucidating the mechanisms by which the “super” tumor suppressor p5353,54 mutant induces tumor regression will provide great insight for developing therapeutic strategies to restore and amplify p53 function.

Citation Format: Mengxiong Wang, Alyssa Kaiser, Kathryn Bieging-Rolett, Colleen Brady, Laura Attardi. Leveraging a p53 “super-tumor suppressor” to understand mechanisms of lung adenocarcinoma regression [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 3403.