bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract C65: Identifying mechanisms of macrophage-mediated metastasis and therapy resistance in PDAC
Authors: Wu Tony J. , Cast Oliver , Memon Danish , Jimenez-Sanchez Alejandro , Machel Anne , Kehrloesser Sebastian , Gill Michael B. , Miller Martin L.
Published: March 2020

Pancreatic ductal adenocarcinoma (PDAC) is characterized by desmoplasia, with macrophages as one of the most abundant, multifunctional immune cell populations in the tumor microenvironment (TME) and a major component of the immune infiltrate. To best improve clinical outcomes, consideration must be placed on targeted therapeutics that blunt heterotypic interactions between tumor cells and supporting cells within the TME. Here, we provide new insight into the dichotomous relationship between epithelial and mesenchymal phenotypes of PDAC cells in 3D culture. We report the ability of PDAC mesenchymal cells to form vascular mimicry-like structures in a 3D in vitro assay of invasion. Additionally, we demonstrate that macrophages have the ability to impart a proinvasive phenotype to PDAC cells when co-cultured in 3D, irrespective of EMT (epithelial-to-mesenchymal transition) status. To elucidate a mechanism for this macrophage-mediated proinvasive phenotype, we employed an unbiased, multi-omics approach. First, PDAC cell lines and primary macrophages were CTAP (cell-type specific labeling using amino acid precursors) labeled and admixed together for a prolonged period of time. To identify cell of origin of novel RNA and proteins, these mixed co-cultures were FACS sorted for downstream RNA-sequencing analysis or harvested in bulk for downstream proteome and secretome analysis. Preliminary integration of cell culture transcriptomes with CTAP-TMT (tandem mass tag) proteomes and secretomes implicates several key epithelial- and macrophage-derived signaling molecules as principal instructing signals for mediating the observed proinvasive phenotype. Blockade of this signaling axis, by inhibition of the signaling molecules or their receptors, disrupted the crosstalk between the two cell types and impaired the ability of macrophages to impart a proinvasive phenotype to PDAC cells. These preliminary preclinical data, recapitulated in vivo, suggest that targeting the TME of patients by using a staging regimen of chemokine inhibitor to disrupt tumor-macrophage cell interactions, followed with therapeutic modalities such as gemcitabine (and/or immunotherapy), would improve upon standard of care and inform future treatment options for PDAC in the clinic.

Citation Format: Tony J. Wu, Oliver Cast, Danish Memon, Alejandro Jimenez-Sanchez, Anne Machel, Sebastian Kehrloesser, Michael B. Gill, Martin L. Miller. Identifying mechanisms of macrophage-mediated metastasis and therapy resistance in PDAC [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr C65.
Abstract I03: Immune contexture of human pancreatic cancer
Authors: Coussens Lisa M.
Published: March 2020

The concept that leukocytes are critical components of solid tumors is now generally accepted; however, their role(s) in regulating aspects of neoplastic progression, and/or response to cytotoxic, targeted, and/or immune therapy is only beginning to be understood. Utilizing de novo mouse models of organ-specific solid tumor development (mammary, cutaneous, and pancreas carcinomas and mesothelioma), we now appreciate that adaptive leukocytes differentially regulate myeloid cell recruitment, activation, and effector function, and in turn, activated tumor-infiltrating myeloid cells engage tissue-based programs to foster malignancy and repress antitumor immunity by a diversity of mechanisms. Treatment of tumor-bearing mice with therapeutic agents that disrupt lymphocyte-myeloid cell interaction, myeloid cell activation, or myeloid cell functionality generally slow primary tumor growth kinetics when combined with cytotoxic therapy; however, their impact on metastases is variable. Similar to organ-specific regulatory programs co-opted to foster primary tumor growth, regulation of metastatic seeding and outgrowth is also regulated by tissue- and organ-specific mechanisms. Based on this, it stands to reason that therapeutic strategies may not be efficacious in both primary and metastatic locations. To be presented will be our recent insights into organ- and tissue-specific regulation of primary and metastatic cancer development by adaptive and innate immune cells, how systemic regulation of humoral immunity and complement-mediated pathways regulate pro- versus antitumor immune responses, and new studies evaluating how attenuating protumor properties of select lymphoid and myeloid cells can be exploited to enhance therapeutic responses to cytotoxic and immune-based therapy. (LMC acknowledges generous support from the NIH/NCI, the Department of Defense Breast Cancer Research Program, Susan G. Komen Foundation, the Breast Cancer Research Foundation, and the Brenden-Colson Center for Pancreatic Health.)

Citation Format: Lisa M. Coussens. Immune contexture of human pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr I03.
Abstract I08: Molecular subtypes - bench to bedside
Authors: Yeh Jen Jen
Published: March 2020

Recent treatment advances in chemotherapy and targeted therapy regimens have provided pancreatic cancer patients and providers with better options. Molecular subtyping for pancreatic cancer has made substantial progress in recent years. With these advances, there is now an opportunity to enable precision medicine approaches for patients with pancreatic cancer. Transcriptomic molecular subtyping is currently an active area of study where several subtyping schemas have been proposed. This talk will present some of these schemas and attempt to reconcile them. Many subtyping approaches rely on the clustering of a new sample with an existing group of samples, the ability to determine the subtype of an individual tumor is limited. In addition, in order to use molecular subtypes in the clinic, subtypes need to be clinically replicable, robust, and have clinical implications. Developing a robust method for subtype classification is needed in order to study the role of molecular subtypes in the context of future clinical trials.

Citation Format: Jen Jen Yeh. Molecular subtypes - bench to bedside [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr I08.
Abstract I09: Tumor-specific T cells reprogram mononuclear phagocytes for destruction of checkpoint blockade-resistant pancreatic cancer
Authors: Dougan Stephanie K.
Published: March 2020

Like virally infected cells, tumors can evade CD8 T-cell recognition by downregulation of MHC class I. Loss of MHC class I and IFNg sensing are major causes of primary and acquired resistance to checkpoint blockade immunotherapy. The cellular (c)-IAPs regulate classical and alternative NF-kB signaling, and induction of noncanonical NF-kB signaling using IAP antagonists mimics costimulatory signaling, augmenting antitumor immunity. We now show that induction of noncanonical NF-kB signaling promotes antitumor immunity across a range of orthotopic and spontaneous pancreatic cancer models, and induces T cell-dependent immune responses even in b2m-/- tumors, demonstrating that direct CD8 T-cell recognition of tumor cell expressed MHC class I is not required. Here we show that MHC class I negative tumors can be controlled in a T-cell dependent fashion by repolarized intratumoral phagocytes. In wild-type mice, but not mice incapable of mounting antigen-specific T cell responses, treatment with IAP antagonists increases phagocytosis of tumor cells, as determined by flow cytometry, imaging flow cytometry, and quantitative immunofluorescence. This mechanism of action inspired combination therapy with CD47 blockade, a strategy that induced curative responses in otherwise refractory preclinical models. To our knowledge, this is the first example of antigen specific immunotherapy for tumors that are refractory to checkpoint blockade due to loss of MHC class I or IFNg sensing.

Citation Format: Stephanie K. Dougan. Tumor-specific T cells reprogram mononuclear phagocytes for destruction of checkpoint blockade-resistant pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr I09.
Abstract I23: Identifying metabolic dependencies in pancreatic cancer
Authors: Kimmelman Alec
Published: March 2020

Pancreatic cancers are highly resistant to currently available therapeutics, which results in a 5-year survival rate of approximately 6%. We believe that this resistance points toward altered cell metabolic pathways. In this regard we have previously shown that that oncogenic Kras promotes a rewiring of pancreatic cancer metabolism, allowing carbon sources to be utilized in a variety of biosynthetic pathways. Importantly, several of these metabolic pathways are critical for tumor growth and therefore represent potential therapeutic targets. Ongoing studies from our group are exploring targeting various aspects of metabolism as therapeutic approaches. Additional studies from our group have demonstrated pancreatic cancers have elevated basal autophagy, which is required for their continued growth. Importantly, inhibition of autophagy pharmacologically or genetically leads to decreased oxidative phosphorylation, a drop in ATP production, and ultimately growth inhibition. These findings have implicated autophagy as a key component of pancreatic cancer metabolism and have motivated the opening of multiple clinical trials assessing the efficacy of hydroxychloroquine as an autophagy inhibitor in pancreatic cancer. These trials are now showing activity of autophagy inhibition in this disease. Recently, we have identified an autophagy/lysosome-dependent metabolic crosstalk that exists between pancreatic tumor cells and the surrounding stroma. Ongoing work from our group seeks to understand the metabolic contributions that autophagy makes in pancreatic tumors as well as further define the metabolic crosstalks. These and other aspects of pancreatic cancer metabolism will be discussed.

Citation Format: Alec Kimmelman. Identifying metabolic dependencies in pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr I23.
Abstract ES1-2: Detecting and Managing Immunotherapy-related Toxicities Wisely
Authors: Schmid P
Published: March 2020

With the increasing use of immunotherapy, multidisciplinary breast cancer teams have to get used to recognising and managing immune-related side effects. Although immune checkpoint inhibitors are generally well tolerated, they can cause a wide range of side effects which often differ from those commonly seen with other types of cancer treatment. These immune-mediated side effects include inflammatory or autoimmune reactions which can resemble autoimmune diseases. Side effect patterns can be highly variable in terms of timing, severity and organ manifestation. They appear at any time, sometimes even months after the last treatment, and can affect any part of the body. The risk of developing immune-related side effects generally increases with longer treatment-duration. Most commonly affected body systems are skin, endocrine organs, the gastrointestinal tract, liver and lungs, but even very rare manifestations such as neurological disorders or myocarditis need to be considered as they can be serious. Before considering patients for immunotherapy, they should be carefully assessed with regards the risk of developing immune-related side effects. Patients with a history of autoimmune disorders are generally at risk of worsening of their autoimmune disease with immunotherapy. Early recognition and intervention are critical for the effective management which often includes the use of corticosteroids and occasionally additional immunosuppressive agents. Interdisciplinary working within oncology groups as well as with associated specialties is critical for optimal patients management. With effective management most immune-related side effects resolve and patients can continue their treatment.

Citation Format: P Schmid. Detecting and Managing Immunotherapy-related Toxicities Wisely [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr ES1-2.
Abstract OT3-12-01: Effect of home-based high-intensity interval training and behavioral modification using information and communication technology on cardiorespiratory fitness and exercise habits among sedentary breast cancer survivors: The habit-B randomized controlled trial in progress
Authors: Tsuji Katsunori , Ochi Eisuke , Shimizu Yoichi , Kuchiba Aya , Narisawa Tomomi , Ishino Yuri , Okubo Ryo , Ueno Taro , Shimazu Taichi , Kinoshita Takayuki , Sakurai Naomi , Matsuoka Yutaka
Published: March 2020

Maintaining high levels of physical activity not only helps to maintain and improve physical health and quality of life, but also plays a role in reducing adverse effects due to cancer treatments. Moreover, a greater degree of cardiorespiratory fitness is associated with reduced risk of all-cause mortality in breast cancer survivors. However, there are no home-based programs for improving cardiorespiratory fitness using body weight exercises for breast cancer survivors. This study assesses the efficacy of the newly developed habit-B program (12-weeks, high-intensity interval training exercise, exercise counseling + guidance, home-based exercise support using information and communication technology, and a wearable device (fitbit versa®)) on peak oxygen uptake (VO2peak; mL/kg/min) compared with treatment as usual. This is a parallel-group, single blind, randomized controlled trial. Subjects are sedentary women aged 20 to 59 years who have received breast surgery in the past 2 to 13 months after diagnosis of invasive breast cancer (Stage I-IIa) and have never received chemo-therapy except for hormone therapy. The primary outcome is difference of change in VO2peak between the groups after 12 weeks. The planned sample size is 60 patients to detect the increase of 2.0 ml/kg/min change in VO2peak with a one-sided significance level of 2.5% and 80% power. The effects of this program on exercise habits, physical activity, physical fitness, fatigue, health-related quality of life, and psychological distress are also be investigated. We have already enrolled 6 subjects as of 2019.7.2, and study will be planned to be finished by 2020 April.

Citation Format: Katsunori Tsuji, Eisuke Ochi, Yoichi Shimizu, Aya Kuchiba, Tomomi Narisawa, Yuri Ishino, Ryo Okubo, Taro Ueno, Taichi Shimazu, Takayuki Kinoshita, Naomi Sakurai, Yutaka Matsuoka. Effect of home-based high-intensity interval training and behavioral modification using information and communication technology on cardiorespiratory fitness and exercise habits among sedentary breast cancer survivors: The habit-B randomized controlled trial in progress [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr OT3-12-01.
Abstract P1-07-01: Cholinergic receptor muscarinic 3 (CHRM3) contributes to breast cancer tumorigenesis through angiogenesis regulation
Authors: Chen Jiawei , Shin Vivian Y , Cheuk Isabella , Siu Jennifer , Kwong Ava
Published: March 2020

Objectives: Cholinergic muscarinic receptors are widely distributed in different human organs with various biological functionals such as synaptic transmission. Accumulating evidence revealed the overexpression of these receptors especially cholinergic receptor muscarinic 3 (CHRM3) with multiple roles in cancer behaviors such as proliferation, apoptosis, angiogenic phenotypes and even epithelial-mesenchymal transition (EMT) through various signaling pathways. However, its roles in breast cancer and angiogenesis still remain elusive.

Methods: Gene expression and patient survival data were from the TCGA and the GTEx projects database. Cells were transfected with scrambled shRNA or CHRM3 shRNA to knockdown gene expression. pcDNA1.3 empty expression vector or CHRM3 expressing vector was used for ectopic expression in the cells. Cell proliferation was examined in different treatment groups by MTT assay and further subjected to cell cycle and apoptosis assay. Expression levels of CHRM3 in paired breast cancer tissues and different cell lines as well as angiogenesis-related markers in cells with different treatments were investigated by qRT-PCR.

Results: CHRM3 expressions were significantly upregulated in triple negative breast cancer (TNBC) subtype, but not other subtypes of breast cancer, and was consistent with the data in TCGA database. Further investigation in different breast cancer cells revealed that CHRM3 expressions were higher in MDA-MB-231 and MDA-MB-468, which are both TNBC cell lines. After treatment with CHRM3-specific inhibitor, 4-DAMP, cell viability was significantly decreased in both MDA-MB-231 and MDA-MB-468 cells. G1-phase arrest and decreased S-phase cell populations and early apoptosis were increased upon 4-DAMP. Moreover, angiogenic markers such as ANG1 and VEGFD were significantly decreased upon CHRM3 knockdown in breast cancer cells or human umbilical vein endothelial cells (HUVEC). Gene correlation analysis from TCGA database indicated a significant positive correlation between CHRM3 and ANG1. Furthermore, CHRM3 shRNA or 4-DAMP treatment inhibited cell proliferation in both MDA-MB-231 and HUVEC.

Conclusions: We found that CHRM3 is upregulated in TNBC tissues and cell lines. CHRM3 confers tumor oncogenic roles, and for the first time, we identified a potential relationship between CHRM3 and angiogenesis in breast cancer. Further experiments are warranted to explore the underlying mechanism of CHRM3 in regulating angiogenesis.

Citation Format: Jiawei Chen, Vivian Y Shin, Isabella Cheuk, Jennifer Siu, Ava Kwong. Cholinergic receptor muscarinic 3 (CHRM3) contributes to breast cancer tumorigenesis through angiogenesis regulation [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-07-01.
Abstract P3-01-24: The cancer-associated TRPC5 opposite strand protein, a novel regulatory factor for cell proliferation in triple negative breast cancer
Authors: Cui Yangyang , Peng Jinghui , Huang Yue , Fu Ziyi , Xie Hui , Wang Shui
Published: March 2020

Background: Breast cancer is the most common malignant tumors worldwide and the leading cause of cancer death among female. Microproteins, a kind of protein which is nearly 100 amino acids in length, have been demonstrated to play important roles in biology and disease. Here, we present a potential microprotein TRPC5 opposite strand (TRPC5OS), which may exert function in breast cancer progression. Methods: Differential expression of TRPC5OS in breast cancer was measured via Immunohistochemistry (IHC) in breast cancer samples and quantitative real-time PCR (qRT-PCR) in cell lines. The effects of TRPC5OS on proliferation and cell cycle progression of breast cancer cells were evaluated by using Cell counting kit-8 (CCK-8), colony formation assay and cell cycle analysis by flow cytometry. The tumor growth in vivo was observed in xenograft model. Co-immunoprecipitation (Co-IP), western blot analysis and immunofluorescent staining were performed to validate the interaction between TRPC5OS and ENO1. Glucose uptake was measured by liquid scintillation spectrometry and involvement of the PI3K and AKT pathways was investigated by western blot analysis. Results: TRPC5OS showed an enhanced expression in breast cancer patient samples predominantly in HER-2 negative breast cancer, especially in triple negative breast cancer (TNBC). Overexpression TRPC5OS increased TNBC cell proliferation, promoted cell cycle progression, enhanced xenograft tumor growth, and associated with PI3K-AKT pathway. In addition, TRPC5OS could enhance glucose uptake via interacting with alpha-enolase (ENO1) and increase the protein level of ENO1, and ENO1 was found to be the functional target of TRPC5OS in TNBC cells. Conclusions: This study demonstrates that TRPC5OS promotes proliferation by interacting with ENO1 and may provide a strategy for future diagnosis of human breast cancer, a new potential therapeutic target for TNBC patients as well. Key words: breast cancer, TRPC5OS, proliferation, ENO1, glucose uptake

Citation Format: Yangyang Cui, Jinghui Peng, Yue Huang, Ziyi Fu, Hui Xie, Shui Wang. The cancer-associated TRPC5 opposite strand protein, a novel regulatory factor for cell proliferation in triple negative breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P3-01-24.
Abstract P5-04-28: Targeting TIGIT and PD-1 in triple negative breast cancer
Authors: Pandey Apurva Kumari , Chauvin Joe Marc , Brufsky Adam , Pagliano Ornella , Ka Mignane , Menna Carmine , McAuliffe Priscilla , Zarour Hassane
Published: March 2020

Background: Triple negative breast cancer is aggressive and has poor prognosis. Tumor infiltrating lymphocytes (TILs) have a prognostic value in triple negative breast cancer. Increased TILs are associated with better disease-free survival and overall survival in triple negative breast cancer (TNBC). Newly approved immunotherapy drug for metastatic triple negative breast cancer patients, Atezolizumab, has shown 10 months improvement in overall survival in for PD-L1 positive group in combination with nab-paclitaxel compared to placebo and paclitaxel. Beyond PD-1 inhibitors, there is a need to improve immunotherapy options in TNBC. TIGIT gene expression in triple negative breast cancer is associated with immune function is linked with improved relapse free survival and overall survival. CD155, a high affinity receptor for TIGIT, is expressed on tumor cells including lung and melanoma. We aim to evaluate the role of TIGIT in regulating immune response to TNBC, TIGIT cooperation with PD-1 in impeding T cell responses to TNBC, and expression of TIGIT ligands on TNBC.

Methods: Fresh TNBC tumor samples were obtained from 10 untreated patients and were used for single cell suspension and multi parameter flow cytometry.

Results: CD8+ and CD4+ TILs in TNBC exhibited higher PD-1 and TIGIT, yet lower CD226 expression as compared to circulating T cells. LAG-3 and TIM3 were expressed at low frequency in CD 8+ and CD 4+ cells. TNBC Tregs display high expression of TIGIT, PD-1, TIM3 but low CD226 expression. TIGIT interacts with CD155 and CD112 with high affinity and both were found to be highly expressed by TNBC tumor cells and APCs. PD-1−TIGIT+ CD8+ TILs are present at high frequency and appear to represent an activated T cell subset. PD-1+Tim-3+TIGIT+ produced less cytokines including interferon gamma, IL-2, and TNF than other CD8+ T cell subsets, representing a dysfunctional T cell subset.

Conclusions: TIGIT is highly upregulated by TNBC CD8+ and CD4+ TILs while the TIGIT ligands are highly expressed by tumor cells and APCs in TNBC. In sharp contrast with metastatic melanoma, high frequency PD-1−TIGIT+CD8+ TILs are present in TNBC. Additional studies will investigate the role of dual PD-1/TIGIT blockade in increasing CD8+ TIL function in TNBC. Such data may support the dual PD-1/TIGIT blockade in TNBCs.

Citation Format: Apurva Kumari Pandey, Joe Marc Chauvin, Adam Brufsky, Ornella Pagliano, Mignane Ka, Carmine Menna, Priscilla McAuliffe, Hassane Zarour. Targeting TIGIT and PD-1 in triple negative breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-04-28.
Abstract P6-13-02: Subcutaneous trastuzumab for the treatment of HER2+ breast cancer in Canada: A cost-minimization study
Authors: Coombes Megan , Yin Lori , Liu Ingrid , Shek Norman , Rusu Flavia , Mukherjee Som
Published: March 2020

Background: There is an urgent need to alleviate the pressure on healthcare resources and decrease treatment burden for patients. Recently, a new fixed dose subcutaneous (SC) formulation of trastuzumab was approved by Health Canada for use in HER2-positive breast cancer (HER2+ BC) patients. Studied in multiple trials and treatment settings, the totality of evidence demonstrated similar safety and efficacy to the IV formulation as well as a strong preference for trastuzumab SC by patients and health care professionals.

Objective: To estimate the incremental costs/savings associated with the use of trastuzumab SC for the treatment of HER2+ BC if reimbursed with the same provincial funding criteria as trastuzumab IV in Ontario, Canada.

Methods: An Excel-based cost-minimization and budget impact model was developed to determine the economic impact of trastuzumab SC in comparison to trastuzumab IV in Ontario. Direct medical costs in the analysis included drug acquisition, drug preparation, drug administration, central venous access device (CVAD), and systemic therapy suite costs.

Results: Early and metastatic HER2+ BC patients treated with trastuzumab SC are expected to generate a net cost savings to the health system compared to treatment with trastuzumab IV. Savings are estimated at $11,943 per eBC patient and $11,943 per mBC patient, representing total savings of $15.8M in Year 1, $19.4M in Year 2, and $23.0M in Year 3. The use of trastuzumab SC in these populations enhances the ability of the payer to manage drug and medical resources, while offering a therapy that is aligned with patient and clinician preferences.

Citation Format: Megan Coombes, Lori Yin, Ingrid Liu, Norman Shek, Flavia Rusu, Som Mukherjee. Subcutaneous trastuzumab for the treatment of HER2+ breast cancer in Canada: A cost-minimization study [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-13-02.
Abstract P6-14-06: Prepectoral direct to implant reconstruction following nipple sparing mastectomy using the TiLOOP bra pocket
Authors: Thill Marc , van Haasteren Viviane , Kelling Katharina
Published: March 2020

Aim: Evaluation of safety, cosmetic outcome and patients satisfaction following nipple sparing mastectomy with prepectoral direct to implant reconstruction using the TiLOOP® Bra Pocket.

Background: TiLOOP® Bra Pocket is a new surgical tool consisting of a large-pore, non-absorbable synthetic mesh made from titanized monofilament polypropylene thread. It is used for immediate prepectoral implant reconstruction to fix the implant on the pectoralis major muscle and to avoid implant rotation.

Material and methodes: Between October 2017 and February 2019, 57 patients underwent nipple sparing mastectomy in the certified breast cancer centre, at the AGAPLESION Markus Hospital, Frankfurt, Germany. Data was collected in a prospective registry. All of the patients underwent a prepectoral direct to implant reconstruction using the new TiLOOP® Bra Pocket. We present the first analysis of this prospective unicentric registry. To measure and to analyse the cosmetic outcome and patients’ satisfaction, the BREAST-Q questionnaire was used, an established modular questionnaire to assess patient reported outcome (PRO).

Results: All of the 57 patients were available for postoperative analysis. In 35/57 (61%) of the cases a seroma occured and was worth to be punctured. The median number of punctures was 4. The volume was 70 ml in average. Seven patients had a postoperative hematoma and had to undergo another surgical procedure. Three patients developed a skin necrosis or severe wound healing problem due to bad quality of the soft tissue and skin mantle and had to undergo implant explantation. One patient suffered from implant infection but could be treated conservatively. The analysis of patients’ reported outcome via the BREAST-Q resulted in a high satifaction rate regarding the cosmetic outcome.

Conclusion: Direct to implant reconstruction with prepectoral implant position by using the TiLOOP® Bra Pocket is a very promising surgical approach. In comparison to a subpectoral implant reconstruction it reduces the duration of surgery, avoids a jumping breast phenomenon and causes less postoperative pain, moreover, it leeds to a high patient satisfaction rate and shows a moderate complication rate. Follow up of our patients will continue. The next analysis will be done after 24 months.

Citation Format: Marc Thill, Viviane van Haasteren, Katharina Kelling. Prepectoral direct to implant reconstruction following nipple sparing mastectomy using the TiLOOP bra pocket [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-14-06.
Abstract A10: The MACSimaTM platform enables high-content imaging for characterization and classification of glioblastoma multiforme
Authors: Reiß Sandy , Tomiuk Stefan , Leyendeckers Heike , Kollet Jutta , Drewes Jan , Brück Wolfgang , Jungblut Melanie , Bosio Andreas
Published: March 2020

Glioblastoma multiforme (GBM), a highly malignant, incurable brain tumor of the primary central nervous system, was subclassified into different subsets. Here, we introduce the new MACSimaTM technology that uses iterative fluorescent staining, image acquisition, and signal erasure with multiple fluorochrome-conjugated antibodies per cycle. We have used this technology to categorize glioblastomas according to the published classification schemes and to identify new glioblastoma-specific markers. Glioblastoma xenografts derived from primary tumors were dissociated into single cells and analyzed by flow cytometry for the expression of cell surface markers, including 371 directly conjugated antibodies. A ranking by percentage of positive cells and staining index was performed, which resulted in a selection of 96 markers for the characterization of primary glioblastoma with the imaging platform MACSimaTM. Sections of primary tumor were fixed with acetone and each sample was exposed to 96 fluorescent labeled antibodies through cycles of antibody reaction, image acquisition, and signal deletion as well as DAPI counterstaining. 2D image stacks were analyzed for antigen quantification and pattern recognition at the level of single pixels or segmented cells. To divide glioblastomas into oligodendrocyte precursors (OPC), differentiated oligodendrocytes (DOC), astrocytic mesenchymals (AsMes) or mixed subtypes, and peritoneal, neuronal, classical or mesenchymal subtypes, we used the detection of previously published markers such as PDGFRα, Olig2, p16, p53, CD44, Nestin, Podoplanin, GFAP, MET, Hes-1, and EGFR. Established antigens such as EGFRvIII, HER2, or IL-13Rα2, some of which were already used in chimeric antigen receptor T cells (CAR T) studies, showed broad inter- and intratumor heterogeneity of expression. Finally, segmentation, clustering, and correlation analysis enabled the identification of new markers that could be used for a more robust classification of glioblastomas and could serve as new potential candidates for targeted immunotherapies. In summary, analysis with the imaging platform MACSimaTM shows a high heterogeneity of protein expression in glioblastomas, together with the ability to classify tumors more deeply and identify new markers that allow selective detection of tumor cells for their potential use in immunotherapy.

Citation Format: Sandy Reiß, Stefan Tomiuk, Heike Leyendeckers, Jutta Kollet, Jan Drewes, Wolfgang Brück, Melanie Jungblut, Andreas Bosio. The MACSimaTM platform enables high-content imaging for characterization and classification of glioblastoma multiforme [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A10.
Abstract A101: Single-cell analysis reveals the pivotal role of the innate immune compartment in aCTLA-4 antitumor response
Authors: Yofe Ido , Jelinski Adam , Solomon Isabelle , Landsberger Tomer , de Massy Marc Robert , Peggs Karl , Quezada Sergio , Amit Ido
Published: March 2020

Immunotherapies have revolutionized and continue to revolutionize cancer patient care; however, much of our understanding of the mechanism of action of these therapies is currently limited. The accumulation of regulatory T cells (Tregs) in the tumor hampers antitumor activity and correlates with bad prognosis in several human cancers. Anti-CTLA-4 monoclonal antibodies (mAbs) have been extensively studied, and their activity depends both on the blockade of the CTLA-4 coinhibitory molecule, as well as the intratumoral depletion of Tregs, increasing effector cell abundance, and favoring tumor rejection. Fc-gamma receptor (FcgR) coengagement has been proven to be important for the action of aCTLA-4, in addition to its Treg-depleting activity via antibody-dependent cellular cytotoxicity (ADCC); however, it is unclear what are the cellular changes involved. We therefore wished to dissect the differences between aCTLA-4 mIgG1, an antibody that only blocks the CTLA-4 receptor, and aCTLA-4 mIgG2a, which has a dual activity of both blocking the receptor and depleting Tregs. To address this, we performed single-cell RNA-seq of infiltrating leukocytes from tumors in mice treated with aCTLA-4 mIgG1, mIgG2a, or left untreated (UT). This high-resolution comparison revealed unique cellular profiles generated by each treatment. While the blocking-only mIgG1 was similar to UT, mIgG2a with ADCC effector function demonstrated major changes. Tumors in mIgG2a treated mice showed an immediate decline of immune suppressive macrophages, and the emergence of proinflammatory monocytes, as well as NK cells and naive CD8 T cells. In addition, mIgG2a-treated mice displayed a gradual increase of CD4 T-cell subsets throughout treatment. Finally, a vast tissue repair signature was observed in later time points of aCTLA-4 mIgG2a treatment, comprising MRC1+ macrophages, neutrophils, and myeloid-derived suppressor cells (MDSCs), while CD8 T-cell abundance declined. In summary, our findings provide an in-depth view of the differences in mechanisms of action between an aCTLA-4 blocking mAb and an optimized blocking-depleting mAb, underscoring how FcgRs coengagement leads to enhanced antitumor response via the innate immune compartment.

Citation Format: Ido Yofe, Adam Jelinski, Isabelle Solomon, Tomer Landsberger, Marc Robert de Massy, Karl Peggs, Sergio Quezada, Ido Amit. Single-cell analysis reveals the pivotal role of the innate immune compartment in aCTLA-4 antitumor response [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A101.
Abstract A104: A stochastic model of tumor-immune evasion predicts sustained coevolution and tumor antigen downregulation
Authors: George Jason T. , Levine Herbert
Published: March 2020

The dynamical interaction between a growing cancer population and the adaptive immune system generates diverse evolutionary trajectories that ultimately result in tumor clearance or immune escape. Here we create a simple mathematical model of T-cell recognition of tumor-associated antigens. We show that declines in T-cell turnover declines explain differences in early incidence data for almost all cancer types. Fitting the model to evolutionary data argues in favor of substantial and sustained immune pressure exerted on a developing tumor, suggesting that measured incidence is a small proportion of all cancer initiation events. Extending our model to account for the number of distinct tumor antigens, we solve for the optimal cancer evasion strategy and demonstrate that such a population-level strategy predicts that the accumulation rate of cancer mutations is a reflection of the tumor microenvironment and determined by the balance of cancer evasion costs and host recognition rate. We apply our framework to combination drug therapy and quantify the difference in predicted efficacy of combination therapy vs. sequential monotherapy. More generally, this framework has significant implications for understanding drug resistance in the face of an adaptive threat.

Citation Format: Jason T. George, Herbert Levine. A stochastic model of tumor-immune evasion predicts sustained coevolution and tumor antigen downregulation [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A104.
Abstract A108: Identification of distinct fibroblast populations with unique roles in PDAC progression and tumor immunity
Authors: Darpolor J. Kebbeh , Zheng Xiaofeng , Yang Sujuan , McAndrews Kathleen M. , Carstens Julienne L. , Phillips Patricia E. , Sugimoto Hikaru , De Sampaio Pedro Correa , Wu Chia-Chin , LeBleu Valerie S. , Kalluri Raghu
Published: March 2020

The desmoplastic reaction in pancreatic ductal adenocarcinomas (PDAC) involves a significant accumulation of immune cells and fibroblasts. Although carcinoma-associated fibroblasts (CAFs) have been associated with immune suppression and immunotherapy resistance in PDAC mouse models, some studies have shown immune-promoting and tumor-suppressing roles of CAFs. The functional diversity of carcinoma-associated fibroblasts (CAFs) remains largely unknown, and identification of immune-regulating subsets would have a substantial impact in augmentation of immunotherapy efficacy. Employing histology, FACs, multiplex immunohistochemistry, single-cell RNA sequencing (sc-RNA-seq), and genetically engineered mouse models, we demonstrate that SMA+ cells are a dominant CAF population in PDAC with tumor-restraining properties (TS-CAFs), as opposed those of the FAP+ CAFs, which demonstrate tumor-promoting activity (TP-CAFs). Analysis of bulk tumor depleted of either TS-CAFs or TP-CAFs showed that TS-CAFs predominantly modulate extracellular matrix (ECM) production, facilitate cell-ECM adhesion, and regulate adaptive immunity, while TP-CAFs exhibit a lineage that is skewed towards a proinflammatory, chemokine-secreting phenotype. Further, scRNA-Seq analyses demonstrate that CAFs share distinct gene expression profiles characteristic of lymphocytic and myeloid lineages. Together our data distinguish two populations of CAFs, one that is tumor suppressing with roles in ECM remodeling and another that is tumor promoting with roles in cytokine production, both with immune-modulating capabilities. Collectively, our study identifies a complex network of functionally heterogeneous fibroblasts during PDAC progression with significant immunotherapeutic implication.

Citation Format: J. Kebbeh Darpolor, Xiaofeng Zheng, Sujuan Yang, Kathleen M. McAndrews, Julienne L. Carstens, Patricia E. Phillips, Hikaru Sugimoto, Pedro Correa De Sampaio, Chia-Chin Wu, Valerie S. LeBleu, Raghu Kalluri. Identification of distinct fibroblast populations with unique roles in PDAC progression and tumor immunity [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A108.
Abstract A12: Inhibition of protease-activated receptor 4 (PAR4) suppresses C4a-induced invasion of lung cancer cells in vitro
Authors: Wang Hongbin , Xiong Lingxin , Wang Zhibin , Wang Yuanyuan , Xu Ling , Zhang Weidong
Published: March 2020

It has been well established that chronic inflammation can cause neoplasm development and cancer cell dissemination. The complement system, an essential component of innate immunity, contains some of the most powerful proinflammatory molecules upon its activation. Recent studies have demonstrated that complement activation components, anaphylatoxins C3a and C5a, can regulate the fate of cancer cells through direct or regulatory effects on cancer cells or immune system. C4a (77 aa) is released from complement component C4 upon the activation of the classical and lectin pathways of the complement system. Our recent study provided the data that C4a acts as an untethered ligand for G protein-coupled receptors, protease activated receptor 1 (PAR1) and PAR4. It is still unclear whether C4a generates any effects on cancer cells through binding to its receptors. In our present study, we want to determine the effect of C4a on the invasive ability of lung cancer cells in vitro, which is supposed to be correlated with lung cancer cell metastasis in vivo. First, we checked the levels of C4a in the plasma from patients of different stages of lung cancer, and our results revealed that the plasma level of C4a from stage IV lung cancer patients is significantly higher than that from stage I lung cancer patients, suggesting C4a might be involved in the metastasis of late-stage lung cancer. In addition, our in silico analysis of data from lung adenocarcinoma and squamous cell carcinoma patients using Kalpan-Meier Plotter online database revealed a negative correlation between PAR4 expression and the overall survival and progression-free survival. Moreover, our in vitro transwell invasion experiments demonstrated that C4a could significantly enhance lung cancer cell invasion in a concentration-dependent fashion, and the blockade of PAR4 by its specific antagonist (ML354) significantly inhibited C4a-induced lung cancer cell invasion in vitro. Our data provide the direct evidence that complement activation fragment C4a induces lung cancer cell invasion through acting on its receptor PAR4, suggesting that targeting PAR4 as a therapeutic intervention might be beneficial for impeding cancer cell metastasis in late-stage lung cancer patients.

Citation Format: Hongbin Wang, Lingxin Xiong, Zhibin Wang, Yuanyuan Wang, Ling Xu, Weidong Zhang. Inhibition of protease-activated receptor 4 (PAR4) suppresses C4a-induced invasion of lung cancer cells in vitro [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A12.
Abstract A18: Investigating CDK4/6 inhibition in triple-negative breast cancer
Authors: Guo Qiuchen , Goreczny Gregory J. , Maynard Adam , Spasic Milos , McAllister Sandra S.
Published: March 2020

The purpose of our study is to investigate the immunologic effects of CDK4/6 inhibitors in triple-negative breast cancer (TNBC), a highly aggressive breast cancer subtype for which there are no targeted therapies. CDK4/6 inhibitors, including the recently FDA approved abemaciclib, show promising response rates in patients with advanced stage hormone receptor-positive (HR+) breast cancer. Our previous report established that CDK4/6 inhibitors promote antitumor immunity by inducing tumor cell antigen presentation by activating tumor endogenous retroviral elements, which induce type III interferon production and MHC-I upregulation (Goel, DeCristo, et al., Nature 2017). In addition, CDK4/6 inhibitors decrease T regulatory cell proliferation without affecting cytotoxic CD8 T-cell numbers. TNBC has been considered a poor candidate for CDK4/6 inhibitor therapy, as tumors often lose Rb protein expression, which is critical for CDK4/6 inhibitor-induced cell cycle arrest. However, reports show around 50%-70% TNBC still has intact RB. We found murine and human TNBC cell lines that express Rb to varying extents and decrease proliferation in vitro in response to abemaciclib. In our preclinical model of TNBC, abemaciclib induced tumor regression. Consistent with previous findings, TNBC tumor cells upregulated MHC-I upon abemaciclib treatment, suggesting increased antigen presentation. Tumor cell-surface PD-L1 was also increased with abemaciclib both in vitro and in vivo, as assessed by flow cytometry and RT-qPCR. These results are encouraging, since a recent trial evaluating αPD-L1 therapy (atezolizumab) reported enhanced progression-free survival in patients with PD-L1+ tumors. These data suggest the potential efficacy of CDK4/6 inhibitors in combination with αPD-L1 in the treatment of TNBC, as we previously reported in our Her2+ model. Abemaciclib also increased total CD8+ and CD4+ T cells and decreased PD1+ CD8 and CD4 cells in the spleen. Furthermore, total numbers of naive CD8+ and CD4+ T cells increased with abemaciclib treatment in the spleen, suggesting a favorable antitumor systemic immunologic effect. CDK4/6 inhibitors might therefore show efficacy in treating TNBC. Deeper analysis of the mechanisms involved in regulating PD-L1 and enhancing naive T cells should enable us to evaluate combination therapies using CDK4/6 inhibitors for this particularly deadly breast cancer subtype.

Citation Format: Qiuchen Guo, Gregory J. Goreczny, Adam Maynard, Milos Spasic, Sandra S. McAllister. Investigating CDK4/6 inhibition in triple-negative breast cancer [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A18.