NOD-SCID Mice Research Articles

Functional Antagonism of Junctional Adhesion Molecule-A (JAM-A), Overexpressed in Breast Ductal Carcinoma In Situ (DCIS), Reduces HER2-Positive Tumor Progression.

Simple SummarySpecific drug targets for breast ductal carcinoma in situ (DCIS) remain elusive, despite increasing disease prevalence and burden to healthcare services. Estrogen receptor (ER)-negative HER2-positive DCIS, associated with the poorest patient prognosis, is in particular need of novel therapeutic avenues. This report provides the first evidence that a cell surface protein called JAM-A is upregulated on human DCIS patient tissues and can be readily targeted by a novel JAM-A-binding peptide inhibitor in separate in vivo models of DCIS. The anti-tumor efficacy and lack of systemic toxicity of this lead inhibitor, coupled with early indications of potential signaling pathways implicated, support the value of future studies investigating JAM-A as a novel drug target in DCIS patients.Breast ductal carcinoma in situ (DCIS) is clinically challenging, featuring high diagnosis rates and few targeted therapies. Expression/signaling from junctional adhesion molecule-A (JAM-A) has been linked to poor prognosis in invasive breast cancers, but its role in DCIS is unknown. Since progression from DCIS to invasive cancer has been linked with overexpression of the human epidermal growth factor receptor-2 (HER2), and JAM-A regulates HER2 expression, we evaluated JAM-A as a therapeutic target in DCIS. JAM-A expression was immunohistochemically assessed in patient DCIS tissues. A novel JAM-A antagonist (JBS2) was designed and tested alone/in combination with the HER2 kinase inhibitor lapatinib, using SUM-225 cells in vitro and in vivo as validated DCIS models. Murine tumors were proteomically analyzed. JAM-A expression was moderate/high in 96% of DCIS patient tissues, versus 23% of normal adjacent tissues. JBS2 bound to recombinant JAM-A, inhibiting cell viability in SUM-225 cells and a primary DCIS culture in vitro and in a chick embryo xenograft model. JBS2 reduced tumor progression in in vivo models of SUM-225 cells engrafted into mammary fat pads or directly injected into the mammary ducts of NOD-SCID mice. Preliminary proteomic analysis revealed alterations in angiogenic and apoptotic pathways. High JAM-A expression in aggressive DCIS lesions and their sensitivity to treatment by a novel JAM-A antagonist support the viability of testing JAM-A as a novel therapeutic target in DCIS.

Gasdermin E mediates resistance of pancreatic adenocarcinoma to enzymatic digestion through a YBX1\u2013mucin pathway

Pancreatic ductal adenocarcinoma (PDAC) originates from normal pancreatic ducts where digestive juice is regularly produced. It remains unclear how PDAC can escape autodigestion by digestive enzymes. Here we show that human PDAC tumour cells use gasdermin E (GSDME), a pore-forming protein, to mediate digestive resistance. GSDME facilitates the tumour cells to express mucin 1 and mucin 13, which form a barrier to prevent chymotrypsin-mediated destruction. Inoculation of GSDME−/− PDAC cells results in subcutaneous but not orthotopic tumour formation in mice. Inhibition or knockout of mucin 1 or mucin 13 abrogates orthotopic PDAC growth in NOD-SCID mice. Mechanistically, GSDME interacts with and transports YBX1 into the nucleus where YBX1 directly promotes mucin expression. This GSDME–YBX1–mucin axis is also confirmed in patients with PDAC. These findings uncover a unique survival mechanism of PDAC cells in pancreatic microenvironments.

Patient derived tumor xenograft study with CDK4/6 inhibitor plus AKT inhibitor for management of metastatic castrate resistant prostate cancer.

176 Background: Despite androgen deprivation therapy, prostate cancer will develop resistance known as castrate resistant prostate cancer (CRPC). Androgen signaling is associated with pathways that influence cell proliferation and survival via cell cycle regulation. AR signaling results in inactivation of Rb tumor suppressor by way of AKT and reduction in intrinsic CDK4/6 inhibitors. Since PTEN loss is found in 40% of mCRPC and AKT pathway is a mechanism of CDK4/6 inhibitor resistance, we hypothesize adding an AKT inhibitor to a CDK4/6 inhibitor will have synergistic activity while delaying CDK4/6 inhibitor resistance. Preclinical xenografts have been shown to recapitulate patient response, therefore, can be used to guide clinical trials using novel combinations. Methods: We have established patient derived tumor xenograft models (GUR-017M, TMA-027 and PRJ-88T) from patients with mCRPC with each having a unique genomic alteration profile. In the clinical setting, GUR-017M was resistant to abiraterone, enzalutamide, cabazitaxel and had exposure to docetaxel. TMA-027 and PRJ-88T were resistant to enzalutamide. We combined a CDK4/6 inhibitor with an AKT inhibitor and treated each of these patient tumors in NOD-SCID mice for a total duration of 40 days. Mice were implanted and separated into 4 groups (placebo, CDK4/6 inhibitor, AKT inhibitor and CDK4/6 + AKT inhibitor) with 10-13 mice in each group. Tumor volumes were measured twice a week. For GUR-017M, abemaciclib (50 mg/kg) was combined with MK2206 (120 mg/kg) and was compared to each placebo and each single agent alone. For TMA-027, palbociclib (50 mg/kg) was combined with ipatasertib (50 mg/kg). After 40 days, tumors were harvested for immunohistochemistry analysis. PRJ-88T was grown as 3D spheroids in ultra-low attachment plates and treated with palbociclib + ipatasertib (10 uM-100uM) to evaluate for synergy. Results: GUR-017M and TMA-027 showed significant delayed tumor growth compared to placebo or either single agent alone. In the GUR-017M group, the final mean tumor volume for the combination group was 149 mm3, compared to 377 mm3 (abemaciclib), 358 mm3 (MK2206) and 527 mm3 placebo group, representing a percent decrease compared to control by 72%, 29%, and 32%, respectively. For TMA-027, the final mean tumor volume for the combination group was 102 mm3, compared to 259 mm3 (palbociclib), 416 mm3 (ipatasertib), and 402 mm3 placebo group, representing a percent decrease compared to control by 75%, 36%, and 4%, respectively. PRJ-88T 3D spheroids showed synergy with palbociclib + ipatasertib. In vivo experiments using PRJ-88T are in progress. Conclusions: The preclinical results show combining CDK4/6 inhibitors with AKT inhibitors is a promising treatment strategy and provides the basis for a clinical trial in patients with mCRPC.

Blockade of Uttroside B-Induced Autophagic Pro-Survival Signals Augments Its Chemotherapeutic Efficacy Against Hepatocellular Carcinoma.

Our previous study has demonstrated that Uttroside B (Utt-B), a saponin isolated from the leaves of Solanum nigrum Linn induces apoptosis in hepatic cancer cells and exhibits a remarkable growth inhibition of Hepatocellular Carcinoma (HCC). Our innovation has been granted a patent from the US (US 2019/0160088A1), Canada (3,026,426.), Japan (JP2019520425) and South Korea (KR1020190008323) and the technology have been transferred commercially to Q Biomed, a leading US-based Biotech company. Recently, the compound received approval as ‘Orphan Drug’ against HCC from US FDA, which reveals the clinical relevance of evaluating its antitumor efficacy against HCC. In the present study, we report that Utt-B promotes pro-survival autophagy in hepatic cancer cells as evidenced by the increased expression of autophagy-related proteins, including LC3-II, Beclin1, ATG 5, and ATG 7, as well as a rise in the autophagic flux. Hence, we investigated whether Utt-B-induced autophagic response is complementing or contradicting its apoptotic program in HCC. Inhibition of autophagy using the pharmacological inhibitors, Bafilomycin A1(Baf A1), and 3-methyl adenine (3-MA), and the biological inhibitor, Beclin1 siRNA, significantly enhances the apoptosis of hepatic cancer cells and hence the cytotoxicity induced by Utt-B. We also found increased expression of autophagy markers in Utt-B-treated xenografts derived from HCC. We further analyzed whether the antimalarial drug, Chloroquine (Cqn), a well-known autophagy inhibitor, can enhance the anticancer effect of Utt-B against HCC. We found that inhibition of autophagy using Cqn significantly enhances the antitumor efficacy of Utt-B in vitro and in vivo, in NOD SCID mice bearing HCC xenografts. Taken together, our results suggest that the antitumor effect of Utt-B against HCC can be further enhanced by blocking autophagy. Furthermore, Utt-B in combination with Cqn, a clinically approved drug, if repurposed and used in a combinatorial regimen with Utt-B, can further improve the therapeutic efficacy of Utt-B against HCC.

Lipophagy-Related Protein Perilipin-3 and Resistance of Prostate Cancer to Radiation Therapy

Radiation therapy is a principal treatment modality for localized and locally advanced prostate cancer (PCa). Metabolic alterations, including lipid metabolism, may reduce treatment efficacy, resulting in tumor relapse and poor therapeutic outcome. In the current study, we investigated the role of the lipophagy-related protein perilipin-3 (PLIN3) and the lysosomal acid lipase (LAL) in PCa response to radiation therapy. We explored the in vitro and xenograft (in NOD SCID and R2G2 mice) response to radiation of either PLIN3-depleted or LAL-depleted hormone-refractory (DU145, PC3) and hormone-responsive (22Rv1) PCa cell lines. Moreover, we evaluated the clinical role of PLIN3 and LAL protein expression in a series of PCa tissue specimens from patients treated with radical radiation therapy. In vitro and in vivo experiments showed reduced proliferation and strong radiosensitization of all studied PCa cell lines upon PLIN3 depletion. In vivo experiments demonstrated the significantly augmented radiation therapy efficacy upon PLIN3 depletion, resulting in extensive tissue necrosis. Overexpression of PLIN3 in tissue specimens was correlated with an increased MIB1 proliferation index, increased autophagy flux, reduced response to radiation therapy, and poor prognosis. The effect of LAL depletion on radiation therapy was of lesser importance. Assessment of PLIN3 expression may identify subgroups of patients with PCa who are less responsive to radiation therapy and at high risk of relapse after irradiation. Whether radiation therapy efficacy may be enhanced by concurrent autophagy or PLIN3 inhibition in this subgroup of patients demands clinical evaluation.

Secretory phospholipase sPLA2-IIAloss impairs tumorigenic and metastatic potential in breast cancer cells

Breast cancer stem cells (BCSCs) are slow cycling cells that escape the traditional chemo-radio-therapy, thereby contributing in resistance and recurrence. Although several markers have been identified, it is still challenging to develop strategies targeting them. In this study, we have isolated BCSCs from MCF-7 cell line using markers CD44+/CD24-/low, which showed higher percentage of mammospheres in CSC population. Moreover, in vivo tumorigenic potential of BCSCs showed as low as 10,000 cells had the ability to develop tumors when transplanted into NOD-SCID mice. We observed an increased level of EMT markers in CSC population. Overexpression of secretory phospholipase sPLA2-IIA was found in CSCs. Further, we have uncovered the upregulation of sPLA2-IIA mediated through JNK signaling in breast cancer cells whereas knockdown of sPLA2-IIA reduces JNK signaling, cell proliferation, EMT and in vivo tumorigenic potential in breast cancer cells. Our study reveals overexpression of sPLA2-IIA in two different breast cancer cells such as MCF7 (ER+,PR+) and a triple negative, MDA-MB-231 (ER-PR-HER2-). Further, the novel role of sPLA2-IIA was discerned by unraveling the molecular mechanism, which regulates the cell proliferation and metastasis in breast cancer cells.

SNAIL Induces EMT and Lung Metastasis of Tumours Secreting CXCL2 to Promote the Invasion of M2-Type Immunosuppressed Macrophages in Colorectal Cancer.

Background: There is increasing evidence that tumour-associated macrophages (TAMs) are critical in the formation of lung metastases. However, the molecular mechanisms of tumour interactions with TAMs via EMT are largely unknown.Methods: The mechanism of lung metastasis was studied in patient tissues. The mechanism of SNAIL regulation of the interaction between mesenchymal cells and M2 macrophages was elucidated using coculture of M2 macrophages and Transwell assays in vitro and in vivo in nude mice and NOD-SCID mice.Results: We demonstrated for the first time that SNAIL and CXCL2 were abnormally overexpressed in colorectal cancer, especially lung metastasis, and were associated with poor prognosis in colorectal cancer patients. We demonstrated that SNAIL promoted the secretion of CXCL2 by mesenchymal cells and induced the activation of M2 macrophages. We found that CXCL2 attracted M2-type macrophages to infiltrate and promote tumour metastasis.Conclusion: These findings suggest that SNAIL promotes epithelial tumour transformation, and that transformed mesenchymal cells secrete CXCL2, which promotes M2 macrophage infiltration and tumour cell metastasis. These findings elucidate the tumour-TAM interaction in the metastatic microenvironment, which is mediated by tumour-derived CXCL2 and affects lung metastasis. This study also provides a theoretical basis for the occurrence of secondary lung cancer.

Inflammatory Immune Responses Trigger Rejection of Allogeneic Fibroblasts Transplanted into Mouse Skin

Fibroblasts, or their homolog stromal cells, are present in most tissues and play an essential role in tissue homeostasis and regeneration. As a result, fibroblast-based strategies have been widely employed in tissue engineering. However, while considered to have immunosuppressive properties, the survival and functionality of allogeneic fibroblasts after transplantation remain controversial. Here, we evaluated innate and adaptive immune responses against allogeneic fibroblasts following intradermal injection into different immune-deficient mouse strains. While allogeneic fibroblasts were rejected 1 week after transplantation in immunocompetent mice, rejection did not occur in immunodeficient γ chain–deficient NOD-SCID (NSG) mice. T-cell- and B-cell-deficient RAG1 knockout mice showed greater loss of fibroblasts by day 5 after transplantation compared with NSG mice (P ≤ 0.05) but prolonged persistence compared with wild-type recipient (P ≤ 0.005). Loss of fibroblasts correlated with the expression of proinflammatory chemokine genes and infiltration of myeloid cells in the transplantation site. Depletion of macrophages and neutrophils delayed rejection, revealing the role of innate immune cells in an early elimination of fibroblasts that is followed by T-cell-mediated rejection in the second week. These findings indicate that the application of allogeneic fibroblasts in tissue engineering products requires further improvements to overcome cell rejection by innate and adaptive immune cells.

Aspirin Inhibition of Group VI Phospholipase A2 Induces Synthetic Lethality in AAM Pathway Down-Regulated Gingivobuccal Squamous Carcinoma.

Background: To elucidate the role of iPLA2/PLA2G6 in gingivobuccal squamous cell carcinoma (GB-SCC) and to ascertain the synthetic lethality-based chemoprevention role of aspirin in arachidonic acid metabolism (AAM) pathway down-regulated GB-SCC. Methods: The in vitro efficacy of aspirin on GB-SCC cells (ITOC-03 and ITOC-04) was assessed by cell proliferation, colony formation, apoptosis, cell migration, cell cycle assay and RNA-seq, while inhibition of PLA2G6 and AAM pathway components was affirmed by qPCR, Western blot and immunofluorescence staining. The in vivo effect of aspirin was evaluated using NOD-SCID mice xenografts and immunohistochemical analysis. Results: We found that aspirin, which has been reported to act through the COX pathway, is inhibiting PLA2G6, and thereby the COX and LOX components of the AAM pathway. The findings were validated using PLA2G6 siRNA and immunohistochemical marker panel. Moreover, a pronounced effect in ITOC-04 cells and xenografts implied aspirin-induced synthetic lethality in the AAM pathway down-regulated GB-SCC. Conclusions: This study reveals that aspirin induces the anti-tumor effect by a previously unrecognized mechanism of PLA2G6 inhibition. In addition, the effect of aspirin is influenced by the baseline AAM pathway status and could guide precision prevention clinical trials of AAM pathway inhibitors.

209.3: Treating iPSC-derived β Cells With Monoclonal Antibody Brentuximab Reduces the Risk of Teratoma Upon Transplantation

Introduction: Induced pluripotent stem cells (iPSC) are promising candidate cells for Beta cell replacement in type 1 diabetes. However, teratoma formation originating from undifferentiated iPSCs contaminating the graft is a critical concern for clinical application. Undifferentiated iPSC express CD30 surface marker at high levels. Here, we hypothesized that Brentuximab vedotin, which selectively targets CD30 and has already demonstrated its efficacy in a model of cardiac regeneration, induces apoptosis in undifferentiated iPSC while sparing the stem cell-derived beta cells. The final aim is thus to increase the safety of iPSC therapy for diabetes and to prevent teratoma formation upon transplantation. Methods: The presence of the protein CD30, was tested on eight different iPSC lines, at different steps of differentiation. The effect of monoclonal antibody anti-CD30 Brentuximab vedotin was tested on undifferentiated iPSC and iPSC-derived Beta cells before transplantation to assess the efficiency in CD30-positive cells depletion and in preventing teratoma formation, respectively. Four weeks after transplantation into the kidney capsule of NOD-SCID mice, graft was explanted and the presence of teratoma was evaluated by gross pathology and histological analysis. Results: Flow cytometry analysis confirmed consistent expression of CD30 in undifferentiated human iPSCs clones (95.33±0.8% in CGTRCiB10, 94.7±0.5% in MODY8, 99.1±0.3% in DRI1, 99.3±0.7% in DRI2 clones). The analysis of the different steps of differentiation revealed that CD30 expression is drastically reduced at DE and PF stages and almost disappeared at the final stages of EN and iBeta. Addition of Brentuximab vedotin in vitro for 24 hours efficiently induced cell death in human iPSCs. The same treatment with the drug on iPSC-derived beta cells (iBeta) did not kill iBeta nor had an impact on iBeta identity and function. Brentuximab vedotin-treated iBeta maintained unchanged morphology, marker expression and capacity to secrete insulin in response to stimuli. Transplantation of no-treated human iBeta into NOD-SCID mice consistently induced teratoma formation, with the appearance of teratoma in the graft at 4 weeks post-transplant, whereas iBeta treated with Brentuximab vedotin prior to the transplantation did not form teratoma. Conclusions: These findings suggest that in vitro treatment with Brentuximab vedotin, targeting the CD30-positive iPSC residual fraction, reduced the tumorigenicity in human iPSC-derived Beta cells, potentially providing enhanced safety for iPSC-based Beta cell replacement therapy in clinical scenarios.

P.150: Alpha-1 Antitrypsin Engineered Mesenchymal Stromal Cells Improves Human Islet Survival via Regulation of Macrophage Activation

Mesenchymal stromal cell (MSC) therapy is a promising treatment option for autoimmune and other diseases. One of the major hurdles besetting clinical islet transplantation is early islet graft death caused by inflammatory events immediately post-transplantation. In a procedure mirroring the clinical setting, we assessed the mechanism of how intrahepatic co-infusion of MSCs leads to better survival of human islets after transplantation into streptozotocin-induced diabetic NOD-SCID mice. We further deciphered whether alpha-1 antitrypsin overexpressing MSCs (AAT-MSCs) exert similar or better protection against naive MSCs. Luciferase imaging studies and immunohistochemistry staining of serial liver sections identified significantly more islets in the livers of the MSC or AAT-MSCs groups compared to the mice receiving islets only. Luciferase+ (Luc+) MSCs co-transplanted with islets remained in the liver for at least one week. Compared to controls, MSC or AAT-MSCs mice showed reduced serum levels of inflammatory-related chemokines, including interleukin 6 (IL-6), interferon-gamma (IFN-g), interleukin-9 (IL-9), among others. In vitro mechanistic studies revealed that MSC or AAT-MSCs suppress IFN-g-induced M1-like CD206-iNOS high macrophages while promoting IL-4-induced M2-like CD206+IL-10 high macrophages. These data suggest that AAT-MSCs protect transplanted islets from early graft death via suppression of inflammation, and can be used to improve the efficacy of islet transplantation. This study was supported in part by the National Institutes of Health (DK105183, DK 120394 and DK118529 to HW) and the Department of Veterans Affairs (VA-ORD BLR&D Merit I01BX004536).

Multiparametric Evaluation of Post-MI Small Animal Models Using Metabolic ([18F]FDG) and Perfusion-Based (SYN1) Heart Viability Tracers.

Cardiovascular diseases (CVD), with myocardial infarction (MI) being one of the crucial components, wreak havoc in developed countries. Advanced imaging technologies are required to obtain quick and widely available diagnostic data. This paper describes a multimodal approach to in vivo perfusion imaging using the novel SYN1 tracer based on the fluorine-18 isotope. The NOD-SCID mice were injected intravenously with SYN1 or [18F] fluorodeoxyglucose ([18F]-FDG) radiotracers after induction of the MI. In all studies, the positron emission tomography–computed tomography (PET/CT) technique was used. To obtain hemodynamic data, mice were subjected to magnetic resonance imaging (MRI). Finally, the biodistribution of the SYN1 compound was performed using Wistar rat model. SYN1 showed normal accumulation in mouse and rat hearts, and MI hearts correctly indicated impaired cardiac segments when compared to [18F]-FDG uptake. In vivo PET/CT and MRI studies showed statistical convergence in terms of the size of the necrotic zone and cardiac function. This was further supported with RNAseq molecular analyses to correlate the candidate function genes’ expression, with Serpinb1c, Tnc and Nupr1, with Trem2 and Aldolase B functional correlations showing statistical significance in both SYN1 and [18F]-FDG. Our manuscript presents a new fluorine-18-based perfusion radiotracer for PET/CT imaging that may have importance in clinical applications. Future research should focus on confirmation of the data elucidated here to prepare SYN1 for first-in-human trials.

Investigating CXCR4 expression of tumor cells and the vascular compartment: A multimodal approach.

The C-X-C chemokine receptor 4 (CXCR4) is G protein-coupled receptor that upon binding to its cognate ligand, can lead to tumor progression. Several CXCR4-targeted therapies are currently under investigation, and with it comes the need for imaging agents capable of accurate depiction of CXCR4 for therapeutic stratification and monitoring. PET agents enjoy the most success, but more cost-effective and radiation-free approaches such as ultrasound (US) imaging could represent an attractive alternative. In this work, we developed a targeted microbubble (MB) for imaging of vascular CXCR4 expression in cancer. A CXCR4-targeted MB was developed through incorporation of the T140 peptide into the MB shell. Binding properties of the T140-MB and control, non-targeted MB (NT-MB) were evaluated in MDA-MB-231 cells where CXCR4 expression was knocked-down (via shRNA) through optical imaging, and in the lymphoma tumor models U2932 and SuDHL8 (high and low CXCR4 expression, respectively) by US imaging. PET imaging of [18F]MCFB, a tumor-penetrating CXCR4-targeted small molecule, was used to provide whole-tumor CXCR4 readouts. CXCR4 expression and microvessel density were performed by immunohistochemistry analysis and western blot. T140-MB were formed with similar properties to NT-MB and accumulated sensitively and specifically in cells according to their CXCR4 expression. In NOD SCID mice, T140-MB persisted longer in tumors than NT-MB, indicative of target interaction, but showed no difference between U2932 and SuDHL8. In contrast, PET imaging with [18F]MCFB showed a marked difference in tumor uptake at 40–60 min post-injection between the two tumor models (p<0.05). Ex vivo analysis revealed that the large differences in CXCR4 expression between the two models are not reflected in the vascular compartment, where the MB are restricted; in fact, microvessel density and CXCR4 expression in the vasculature was comparable between U2932 and SuDHL8 tumors. In conclusion, we successfully developed a T140-MB that can be used for imaging CXCR4 expression in the tumor vasculature.

Abstract 10499: The Heart Failure-Induced Long Non-Coding RNA Heat4 Reduces the Inflammatory Response of Non-Classical Monocytes and Mediates Regeneration After Vascular Injury

Background and Purpose: Activation of the immune system correlates with the severity and the prognosis of patients with heart failure (HF). This study aims to identify and characterize long non-coding RNAs (lncRNAs) as a potential mechanistic link between the pathophysiology of HF and the activation of the immune system. Methods and Results: Using next-generation sequencing, we identified the lncRNA Heat4 to be 2-fold upregulated in the blood of patients with HF compared to controls (N=4; p&lt;0.05). Heat4 induction was validated in an independent second patient cohort via qPCR (HF: N=63; Controls: N=38; p&lt;0.05). Magnetic-activated cell sorting revealed non-classical monocytes as the primary cellular source of Heat4 (N=4; 3.37-fold compared to classical monocytes; p&lt;0.05). This finding was verified by single-cell RNA sequencing. Overexpression of Heat4 in monocytes decreased inflammation, as indicated by a reduction of Interleukin 1β (IL1β) expression (N=6; 38.71% reduction). Accordingly, reduction of Heat4 caused upregulation of IL1β levels (N=5; 1.51-fold; p&lt;0.05). In vivo , overexpression of Heat4 in human monocytes increased vascular regeneration after injury of the carotid artery in NOD-SCID mice (N=6; 1.85-fold compared to injection of control monocytes; p&lt;0.05). Conclusion: The long non-coding RNA Heat4 is elevated in the blood of HF patients. Mechanistically, Heat4 limits the extent of the inflammatory response of non-classical monocytes and leads to a faster regeneration after vascular injury. Therefore, lncRNAs such as Heat4 may provide novel targets for future heart failure treatments.

TMOD-19. FROM PATIENT TO PETRI DISH: INCREASING PATIENT-DERIVED GLIOBLASTOMA CULTURE EFFICIENCIES TO 95%

Abstract INTRODUCTION The search for effective therapies for gliomas is progressively moving towards patient-specific medicine. In order to test patient-tailored therapies, it is vital to develop protocols for reliable establishment of patient-derived glioma cultures. We present a method for reliable culture establishment, with a 95% success rate in 114 consecutive high-grade samples. METHODS Cell cultures were established from either traditionally-resected tumor tissue or ultrasonic surgical aspirator (CUSA) derived tissue fragments, and expanded in serum-free culture, with selection of astrocytic populations if required. Cultures were started from single cells or small tumor fragments of 0.5-3mm (3D). Whole exome and RNA sequencing were carried out with the Illumina Novaseq and HiSeq platforms. Methylation profiling was performed with the Infinium MethylationEPIC array. Cultures and tumors were compared through analysis of single nucleotide polymorphisms and copy number profiles with the Infinium Global Screening Array. Intra-tumoral heterogeneity in cultures was investigated with single-cell transcriptomic sequencing (SORT-seq). We studied tumor-initiating potential by orthotopic injection of cultures in NOD-SCID mice. RESULTS Cultures started from single cells were established from CUSA material more efficiently (92%) than from traditional resection material (70%). 3D-derived cultures had a higher overall efficiency (95% for CUSA, 85% for traditional resection material). We confirmed high concordance in driver mutations, copy number and methylation profiles between tumors and derived cultures. Transcriptomics analysis, comparing tumors and derived cultures, revealed high consistency in gene expression distribution as demonstrated by correlation analysis (r=0.88). Singe-cell RNA-seq shows increased heterogeneity in CUSA derived-cultures, and decreased heterogeneity with passaging over time. Cultures faithfully produce tumors after orthotopic injection in NOD-SCID mice. CONCLUSION We present a highly successful method for the establishment of glioma cultures from patient material, with CUSA-derived cultures revealing greater heterogeneity. Cultures faithfully represent important molecular characteristics of parental tumors and can be used to test potential therapies in vitro.

AO-176, a Differentiated Clinical-Stage Anti-CD47 Antibody, Demonstrates Potent Anti-Tumor Activity across Multiple Preclinical Models of B Cell Neoplasms

Upregulation of CD47, the “don't eat me” signal, on the surface of tumors to evade immune surveillance is a common escape mechanism utilized during hematological malignancy and solid tumor development, progression, and relapse. We recently reported that AO-176, a clinical stage humanized anti-CD47 IgG2 antibody, possesses differentiated characteristics such as preferential binding of tumor cells compared to normal cells, negligible binding to red blood cells, non-ADCC direct tumor killing and elicits immunogenic cell death and DAMP induction, all in addition to single-agent phagocytosis. In vivo, AO-176 has exhibited broad anti-tumor activity in preclinical xenograft models of multiple myeloma (MM), acute myeloid leukemia, T cell acute lymphoblastic leukemia, and Burkitt lymphoma. In this study, the anti-tumor activity of AO-176 in an expanded set of preclinical models of B cell neoplasms was evaluated. We assessed In vivo anti-tumor activity in a diffuse large B cell lymphoma (DLBCL) preclinical xenograft model by inoculating Toledo cells into NSG mice and treating once weekly with either 25 mg/kg AO-176 or human IgG2 isotype control. Treatment with AO-176 resulted in profound tumor shrinkage, achieved complete responses in 8/10 mice, and extended survival for all treated mice through the 46 day dosing period, compared to all isotype control treated tumors reaching endpoint by day 21.Having previously observed significant tumor shrinkage and extension of survival in subcutaneous xenograft models of MM, we sought to evaluate anti-tumor activity of AO-176 in an orthotopic model of MM. Luciferase expressing RPMI-8226 cells were inoculated via intratibial injection into NOD-SCID mice and treated with either 25 mg/kg of AO-176 or human IgG2 isotype control once weekly. AO-176-treated mice showed significant reductions of bioluminescence on study days 7, 21, 35, and 41, and serum paraprotein at study end. Evaluation of bone lesions by x-ray showed significantly reduced average bone lysis score in the AO-176 treatment group at study day 41. We then compared the anti-tumor activity of AO-176 against the second generation proteosome inhibitor carfilzomib in a myeloma xenograft model. AO-176 dosed at 25 mg/kg once weekly achieved 72% TGI, compared to 47% and 27% TGI for tumors treated with 5 mg/kg and 2.5 mg/kg carfilzomib at day 29 post treatment.To elucidate the pathways and processes that may be underpinning the anti-tumor activity of AO-176, we performed bulk RNA sequencing on AO-176 or isotype control-treated tumors harvested at multiple time points from a MM xenograft model we previously reported as exhibiting profound sensitivity to AO-176 in vivo. Murine transcripts from harvested tumor RNA were evaluated to assess differences in immune infiltrate resulting from AO-176 treatment. Days 3 and 7 post treatment with AO-176 showed the greatest number of differentially expressed genes compared to control treated tumors. The top enriched pathway on day 3 was microglia phagocytosis. Principal component analysis of gene expression indicated partitioning of day 3 post AO-176 treatment from the rest of the groups. Furthermore, deconvolution of abundances of infiltrating immune cells using CIBERSORT via TIMER analytical tool showed an enrichment of macrophages relative to other cell types on day 3 post treatment.To extend our RNA sequencing findings, we then sought to evaluate intratumoral immune cell populations after AO-176 treatment in a subcutaneous MM xenograft model. MM cells were inoculated into NOD-SCID mice, then treated with 25 mg/kg AO-176 or human IgG2 isotype control. At 48 hours post treatment, tumors were harvested, and we observed an increase of macrophages in the AO-176 treated tumors, confirming our previous results.In summary, the robust preclinical data in DLBCL and MM warrants further development of AO-176 for treatment of hematological malignancies. AO-176 is being evaluated in phase 1/2 clinical trials for the treatment of patients with solid tumors (NCT03834948) and with MM (NCT04445701). DisclosuresWilson: Arch Oncology: Current Employment. Richards: Arch Oncology: Current Employment. Andrejeva: Arch Oncology: Current Employment. Capoccia: Arch Oncology: Current Employment. Puro: Arch Oncology: Current Employment. Donio: Arch Oncology: Current Employment. Hiebsch: Arch Oncology: Current Employment. Kashyap: Arch Oncology: Current Employment. Pereira: Arch Oncology: Current Employment.

Identifying Long Noncoding RNA Dependencies Using CRISPR Interference (CRISPRi)-Based Platform in Multiple Myeloma

Identifying Long Noncoding RNA Dependencies Using CRISPR Interference (CRISPRi)-Based Platform in Multiple Myeloma

A BCL2L1 Armoured BCMA Targeting CAR T Cell to Overcome Exhaustion and Enhance Persistence in Multiple Myeloma

Chimeric antigen receptor (CAR) T cells targeting the B-cell maturation antigen (BCMA) have resulted in deep responses in patients with relapsed MM however most remissions are not sustained. While cellular and molecular mediators of relapse post CAR T therapy in MM are not fully delineated, current data suggest three possible mechanisms including the lack of persistence of the CAR T cell product, acquired exhaustion and less commonly loss of BCMA expression.Using CITE-seq we measured the expansion of variable T cell subsets, T cell specific activation and inhibitor markers and their functional states in serial blood and marrow samples (n=10) collected from patients treated with BCMA targeting CAR T cells. CAR T cells were identified by the expression of the chimeric CAR T cell transcript. With the exception of one patient where biallelic loss of BCMA was identified at relapse, CAR T cells of resistant patients were enriched with terminally exhausted CD45RA+ cells with loss of CD28, low BCL2L1 (gene encoding BCL-XL) expression, high CD57 with co-expression of checkpoint inhibitors (LAG3, TIGIT and PD1). The lack of persistence of the CAR T cells product was notable in all relapsing patients consistent with an activation induced cells death (AICD) specially in the setting of chronic antigenic stimulation. Cognizant of the role BCL-XL plays in T cells survival in response to CD28 co-stimulatory signaling, we postulated that increasing BCL-XL expression is a feasible strategy to enhance CAR T cell resistant to AICD, improve their persistence and anti-BCMA reactivity. To this goal, we designed a 2nd generation lentiviral CAR construct where the anti-BCAM scFV-41BBz CAR and the BCL2L1 cDNA were linked with self-cleaving 2A sequence. The efficiency in eradicating MM cells of this BCL-XL armored CAR (BCMA_BCL2L1_CAR) was compared to that of non-unarmored CAR (BCMA_CAR) in vitro and i n vivo studies. While BCMA_BCL2L1_CAR and BCMA_CAR were equally cytotoxic to OPM2 MM cells, in MM cell lines expressing the FAS death receptor ligand FASLG (MM1S, OCMY5 and H929) BCMA_BCL2L1_CAR viability and cytolytic activity was significantly superior to that of unarmored BCMA_CAR. Of note, the expression of FASLG, a known interferon response gene, was upregulated in H929 cells when co-cultured with CAR T cells. Importantly, under chronic antigenic stimulation conditions (FIG 1A), where CAR T cells were stimulated every 6 days over a 28 days period with irradiated OPM2 cells, we found no phenotypic difference between BCMA_BCL2L1_CAR and BCMA_CAR with respect to the composition of effector memory T cells (Tem: CCR7− CD45RO+ CD45RA−) or central memory T cells (Tcm: CCR7+CD45RO+CD45RA−) or terminal effector / exhausted T cells. However, under these chronic antigenic stimulation conditions, the CAR T cells viability, proliferation (FIG 1B) and anti-MM cytotoxic activities (FIG 1C) of the BCMA_CAR were dramatically reduced compared to that of the BCL2L1 armored CAR. Furthermore, in initial animal studies where NOD-SCID mice were tail vein injected with 2e6 OPM2 MM cells transduced with a luciferin reporter gene, followed 10 days later by control T cells, BCMA_CAR or BCMA_BCL2L1_CAR T cells IV injection, and despite a skewing to a larger initial disease burden in the BCMA-BCL2L1-CAR group, BCL2L1 armored CAR T cells resulted in more prolonged disease control and animal survival compared to the BCMA_CAR treated mice (FIG 1D).Our studies indicate that BCL2L1 blockade of AICD not only enhanced the viability and proliferation of BCMA targeting CAR T cells but surprisingly also reduced their functional exhaustion. Our findings provide an novel approach for CAR T optimization and overcoming disease relapse resulting from lack of persistence and/or T cells exhaustion. [Display omitted] DisclosuresNeri: Amgen: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria. Bahlis: Sanofi: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Genentech: Consultancy; Janssen: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; GlaxoSmithKline: Consultancy, Honoraria; BMS/Celgene: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria.

Investigation of the Heterogeneity Evolution and Drug Resistance Mechanism of Diffuse Large B-Cell Lymphoma Under the Treatment of a Novel HDAC Inhibitor LAQ824

Aims:Diffuse large B-cell lymphoma (DLBCL), the most frequent malignant lymphoma subtype, is a group of highly invasive diseases with great heterogeneity in genomic alterations, clinical characteristics, morphological manifestations, treatment response and prognosis. Although most DLBCL patients can be cured by immunochemotherapy, nearly 40% of DLBCL patients still develop drug resistance and relapse. For relapsed/ refractory (R/R) DLBCL patients, there is still no optimal treatment. The heterogeneity and clonal evolution of tumor cells are the core driving forces for the occurrence and development of DLBCL, and the root causes for their refractory, recurrence and drug resistance. In this study, we screened out a novel small molecule compound effectively killing DLBCL cells, and analyzed its potential mechanism of anti-tumor. Meanwhile, by using single cell sequencing technology, we try to further investigate the heterogeneity and clona evolution and drug resistance mechanism of DLBCL under different drug pressure, explore core driver factors of drug resistance, evaluate and develop new treatment strategies.Methods:In this study, GEXSCOPE microfluidic platform was used for single-cell transcriptome sequencing. Seruat software was used for cell type recognition and clustering analysis. In order to further investigate the molecular mechanism of LAQ824 inducing the apoptosis of DLBCL cells and explore the target of LAQ824, antibody chip was performed to detect the phosphorylation of related signaling pathway. Gene expression was detected by real-time qPCR and Western blot. ChIP, RNA interfering (RNAi) and dual-luciferase activity assay were performed to validate the potential drug resistance targets for LAQ824. Moreover, WES of 21 DLBCL cell lines were performed to map mutations and analyze the correlation between related mutations and LAQ824 resistance. In this study, we established DLBCL animal models using NOD SCID mice transplanted with DLBCL cell lines, by which we could evaluate the tumor inhibition efficiency of LAQ824 alone and/or combination with other small molecular inhibitors.Results:Using GDSC database, we screened out Dacinostat (LAQ824), a novel HDAC inhibitor, was highly sensitive that could effectively induce the apoptosis of most DLBCL cells at low concentrations. Functional assay showed that LAQ824 could inhibit cell proliferation and promote apoptosis of tumor cells. LAQ824 treatment could significantly upregulate the acetylation level of histone H3 within a certain concentration range, and the DNA damage repair function of DLBCL cells was supressed by inhibiting Chk2 expression, thus significantly inducing cell apoptosis and effectively killing DLBCL cells. Meanwhile, through single-cell sequencing analysis, it was found that c-Fos could be activated under certain drug pressure of LAQ824. As a potential drug-resistant core driver gene, the expression level of c-Fos is highly correlated with IC50 of LAQ824 and the prognosis of patients with DLBCL, which can be used as a sensitivity indicator of LAQ824. Treatment with c-Fos inhibitor combined with LAQ824 can significantly improve the tumor inhibition rate, validated both in vitro and in vivo, which is expected to alleviate the recurrence and drug resistance of DLBCL patients.Conclusions:In general, we explores potential therapeutic drugs for DLBCL parients, adjusts and explores new clinical treatment strategies on this basis, and provides theoretical basis and data support for the realization of individualized precise treatment and the solution of DLBCL recurrence and drug resistance. DisclosuresNo relevant conflicts of interest to declare.

Cigarette Smoke or Cigarette Condensate Exposure Accelerates Growth of FLT3-ITD AML Models, Induces Oxidative Stress, and Alters DNA Methylation

Cigarette Smoke or Cigarette Condensate Exposure Accelerates Growth of FLT3-ITD AML Models, Induces Oxidative Stress, and Alters DNA Methylation