Class I PI3K Isoforms Exert a Differential Role On Survival and Cell Trafficking In Multiple Myeloma

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3159-3159
Author(s):  
Ilyas Sahin ◽  
Feda Azab ◽  
Michele Moschetta ◽  
Yuji Mishima ◽  
Brian Tsang ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Tumor Growth ◽  
Tumor Progression ◽  
Tumor Cells ◽  
Research Funding ◽  
Class I ◽  
Cell Trafficking ◽  
And Migration

Abstract Background The phosphatidylinositol-3 kinase (PI3K) pathway is a critical regulator of tumor progression, protein translation and cytoskeletal dynamics, collectively required for cell proliferation, survival, adhesion and migration in many malignancies including multiple myeloma (MM). Despite the absence of mutations in the PI3K/Akt genes, many studies have demonstrated that this pathway is constitutively activated in MM cells. In this study, we investigated the role of inhibition of class I PI3K isoforms known as p110α, p110β, p110γ and p110δ in cell trafficking of MM cells using isoform-specific knockdown (KD). We have also evaluated the effect of pan-PI3K inhibitior, NVP-BKM120, on survival, adhesion and migration of MM cells both in vitro and in vivo. Methods The baseline expression of class I PI3K isoforms in MM cell lines (MM.1S, OPM1, OPM2, H929, RPMI, INA6, U266, and U266LR7) has been evaluated by immnunobloting. MM tumor cells (MM.1S-GFP+/luc+) were infected with lentivirus mediated shRNA targeting class I PI3K isoforms. RT-qPCR and immunoblotting were performed to show infection efficiency. In vivo tumor growth of isoform specific KDs were assessed by using in vivo bioluminescence (BLI) in SCID mice. Detection of circulating MM-GFP+ cells ex vivo was performed by flow cytometry. Analysis of circulating tumor cells for each isoform-specific KD cells against relative tumor volume was performed by lineer regression using GraphPad software. Survival, adhesion and migration of KD cells were tested by MTT, adhesion and migration in vitro assay, respectively. NVP-BKM120, a pan-PI3K-inhibitor (Novartis, MA) has been tested both in vitro and in vivo. Ex vivo detection of mobilization and tumor growth of MM cells (MM.1S-GFP+/luc+) treated with 1) vehicle; 2) NVP-BKM120 in SCID mice were assessed by using flow cytometry and in vivo BLI. Homing of MM cells to the BM of mice pre-treated with NVP-BKM120 was evaluated by in vivo confocal. Increased concentrations of NVP-BKM120 have been tested on survival, cell cycle and apoptotic pathways in MM cells, by using MTT, PI staining in flow cytometry and immunoblotting, respectively. NVP-BKM120 induced dose-dependent effect on chemotaxis and adhesion of MM.1s to BM stromal cells (BMSCs) and fibronectin were tested by migration and adhesion assays. Results PI3K-p110β was highly expressed in all cell lines; while other isoforms were expressed in some of the MM cell lines tested. Of note, MM.1S expressed all isoforms. Mice injected with PI3K isoform specific knockdown MM.1S cells presented with different tumor burdens; p110β and p110δ mice showed significantly slower tumor progression compared to scramble control cell line (P<.05), whereas tumor growth was similar in p110α and p110γ to control mice. We next compared the number of circulating tumor cells (CTCs) at the same tumor burden between groups, which showed only p110β presented with a higher number of CTCs compared to the scramble group (P=0.01). In vitro, we observed reduced adhesion and enhanced migration of KD cells compared to control with no cell survival difference. The effect of pan-inhibition of PI3K with NVP-BKM120 induced MM cell mobilization from the BM to the circulation (Vehicle: 0.002 % vs NVP-BKM120: 0.023%; P<.05). This was supported by the inhibition of homing of MM cells to the BM (84% decrease) in the mice pre-treated with NVP-BKM120 (P<.05). Furthermore, treatment of mice with 50mg/kg of NVP-BKM120 once a day by oral gavage for five weeks significantly decreased the rate of tumor progression in MM compared to the vehicle treated group, as shown by BLI (69% decrease, P<.01). NVP-BKM120 decreased the activation of adhesion-related signaling in MM cells induced by co-culture with stroma, including pFAK, pSrc, pCoffilin and pMLC, as shown by immunoblotting. Moreover, it caused cell cycle arrest, as detected by PI staining and analyzed by flow cytometry. Conclusion This study suggests that inhibition of Class I PI3K isoforms, particularly p110β and p110δ, can play an important role in the regulation of cell trafficking in MM by disrupting adhesion of MM cells to the BM and inducing mobilization. Thus, pan-PI3K inhibition by NVP-BKM120 is a promising approach, which may enhance therapeutic response and overcome resistance in the treatment of MM. Disclosures: Ghobrial: Onyx: Advisoryboard Other; BMS: Advisory board, Advisory board Other, Research Funding; Noxxon: Research Funding; Sanofi: Research Funding.

Hypoxia Promotes Dissemination of Multiple Myeloma Through Acquisition of Endothelial to Mesenchymal Transition (EMT) Features

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 471-471
Author(s):  
Abdel Kareem Azab ◽  
Jinsong Hu ◽  
Phong Quang ◽  
Feda Azab ◽  
Costas Pitsillides ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Tumor Progression ◽  
Board Of Directors ◽  
Research Funding ◽  
Tumor Burden ◽  
Advisory Committees ◽  
Mesenchymal Transition ◽  
E Cadherin

Abstract Abstract 471 Multiple myeloma (MM) is characterized by widespread dissemination of the MM cells at diagnosis associated with multiple focal bone lesions, implying (re)circulation of MM cells into the peripheral blood and (re)entrance or homing into new sites of the BM. However, the driving force for MM cells to leave the BM, egress, and home to new BM niches is still not well understood. Hypoxia (low oxygen) in solid tumors was shown to promote metastasis in solid tumors through activation of proteins involved in the endothelial to mesenchymal Transition (EMT). In this study, we hypothesized that MM tumor progression induces hypoxic conditions, which in turn activates EMT related proteins and promotes metastasis of MM cells. To test this hypothesis, we examined levels of hypoxia in MM cells at different stages of tumor progression in vivo in two animal models: the first by injecting MM1s cell to SCID mice, and the second by injecting 5T33MM cells to C57BL/KaLwRijHsd mice. Hypoxic markers were examined using flow cytometry and immunohistochemistry. We found that tumor progression induced hypoxia in both the MM cells and the tumor microenvironment. Similarly, hypoxia induced genes (HIF1a, HIF1b, HIF2b, CREBBP, HYOU1, VEGF1, HIF1a-inhibitory protein) were increased in MM patients (n=68) compared to plasma cells from healthy donors (n=14). Using flow cytometry we found that the number of circulating MM cells increased with the progression; however, the correlation was observed in late stages of the progression but not in the early stages. A better direct correlation was achieved with the hypoxic state of the MM cells in the BM. Circulating MM cells were more hypoxic that MM cells in the BM (especially at low tumor burden). Moreover, we found that the level of hypoxia in MM cells in the PB did not correlate with the hypoxia in the BM. Next, we tested the mechanism in which hypoxia induces cell egress. We found that MM cells isolated from MM patients have higher gene expression of EMT inducing proteins (E-cadherin, SNAIL, FOXC2, TGFb1) in parallel to a decrease of expression in E-cadherin, and we confirmed the downregulation of E-cadherin expression in correlation with the increase of hypoxia in MM cell and cells in the BM microenvironment in vivo. Culturing MM cells under hypoxic conditions increased the expression of HIF1a and HIF2a. In parallel, hypoxia induced acquisition of EMT related features including downregulation of E-cadherin, upregulation of SNAIL, and inhibition of GSK3b. In addition, hypoxia decreased the adhesion of MM cells to stromal cells. To complete the metastatic process after egress, MM cells need to home to new sites in the BM. Therefore we investigated the effect of hypoxia on expression of CXCR4, chemotaxis and homing of MM cells to the BM. Using flow cytometry we found a direct correlation between hypoxia and the expression of CXCR4 in MM cells in vivo using the SCID-MM1s model. These results were confirmed in vitro, where hypoxia increased the expression of CXCR4 at protein and mRNA levels in MM cells. Moreover, the expression of CXCR4 in MM cells isolated from the PB was higher than cells isolated from the BM especially at low tumor burden, correlating with higher hypoxic state of the circulating tumor cells. Functionally, hypoxia increased the chemotaxis of MM cells towards SDF1a in vitro and, using in vivo confocal microscopy, it was shown to accelerate the homing of MM cells to the BM in vivo. To demonstrate that the chemotaxis and homing were CXCR4 dependent, we treated the hypoxic MM cells with AMD3100 (a CXCR4 inhibitor) and showed that it inhibited chemotaxis in vitro and homing of MM to the BM in vivo. In conclusion, we demonstrate that tumor progression induces hypoxia in the MM cells and in the BM microenvironment. Hypoxia activates EMT-related machinery in MM cells, decreases expression of E-cadherin and consequently decreased the adhesion of MM cells to the BM, and enhance egress of MM cells to the circulation. In parallel, hypoxia increases the expression of CXCR4, and consequently increased the migration and homing of MM cells in from the peripheral blood to the BM. Further studies to manipulate hypoxia in order to regulate tumor dissemination as a therapeutic strategy are warranted. Disclosures: Roccaro: Roche: . Kung:Novartis Pharmaceuticals: Consultancy, Research Funding. Ghobrial:Novartis: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Millennium: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol-Myers Squibb: Research Funding; Noxxon: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.

scholarly journals 835 Harnessing the microbiota to increase response rates to immunotherapy

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A876-A876
Author(s):  
Valentina Ferrari ◽  
Alessia Melacarne ◽  
Francesca Algieri ◽  
Maria Rescigno
Keyword(s):  
Flow Cytometry ◽  
Statistical Analysis ◽  
Tumor Cells ◽  
Cell Lines ◽  
Hla Class I ◽  
Surface Expression ◽  
Vehicle Control ◽  
Class I

BackgroundTumor cell clearance by cytotoxic T lymphocytes (CTL) requires expression of relevant antigens on HLA Class I molecules on the surface of tumor cells. Reduced levels of HLA Class I expression is a common method of immune escape, as it hampers tumor-specific CTLs’ ability to detect, recognize, and eliminate tumor cells. Recent data have shown that gut microbiota have a major impact on the clinical response to immune checkpoint inhibitors (ICIs), which could be due to a direct effect on malignant cells. Our hypothesis is that microbiota can influence the immune response by altering HLA Class I expression on tumor cells.MethodsTo investigate the ability of bacteria-based products to upregulate HLA Class I expression, we tested two different proprietary microbial derivatives (MDs) on multiple murine and human tumor primary and immortalized cell lines from various tissues, including: breast, myeloid, melanoma, and colon. We next examined if the change in HLA expression was functional by measuring activation levels and cytotoxic capacity of MART-1-specific CTLs following tumor cell treatment with MDs. Lastly, we administered MDs intra-peritoneally in 4T1-bearing Balb/c mice to sensitize 4T1 tumors to combination treatment with anti-PD-1 ICI.ResultsOur results to date show that in vitro treatment with MDs can upregulate surface HLA, albeit not uniformly across all tumor types, with breast and myeloid tumor cells showing the largest increase across the cell lines tested (figure 1). The MD-dependent HLA increase subsequently boosted CTL recognition of tumor cells without increasing background reactivity. The increased CTL degranulation correlated to the tumor cells’ increased surface HLA expression and was consistent whether the antigen was endogenous (5% increase, p<0.0001, figure 2A) or added exogenously (15%–30% increase, p<0.01 and p<0.0001 figure 2B). In combination with anti-PD-1 in vivo, MD treatment significantly abrogated tumor growth when compared to anti-PD-1 combined with the vehicle control (p<0.0001, figure 3A) and tumors harvested from MD-treated mice expressed higher levels of MHC Class I compared to the vehicle control cohort (p<0.05, figure 3B). Additionally, splenocytes from MD-treated mice showed increased recognition of 4T1 tumor cells when re-challenged in vitro (10% increase in CD8+41BB+ cells, p<0.0001, figure 3C).Abstract 835 Figure 1Class I surface expression after MD treatment. (A) breast (B) colon (C) melanoma and (D) myeloid human cancer cell lines were incubated with 5 (light bars) or 10 (dark bars) mg/mL MD#1, MD#2, and 10 mg/mL respective vehicle control (empty bars). (E) and (F) were treated with 10 mg/mL (dark bars) MD#1, MD#2, or respective vehicle controls (empty bars). After 48 hours, HLA Class I (A-D), H-2kb (E), and H-2kd (F) surface expression was measured by flow cytometry. Experiments repeated at least in duplicate. Statistical analysis by 2-way ANOVA, *p<0.05, **p<0.01, ***p<0.001, ****p<0.0001.Abstract 835 Figure 2Antigen-specific CTL activation. Tumor cells were pre-treated for 48 hours with 10 mg/mL vehicle or MD, then washed and co-cultured for 5 hours with MART-1 specific CTL. A) primary HLA-A2+ melanoma cells that are negative (Mel12) or positive (Mel13) for the MART-1 antigen, and B) Thp1 loaded or not with MART-1 peptide. CD8+CD107a+ cells measured by flow cytometry. Experiments repeated in triplicate, statistical analysis by two-way ANOVA.Abstract 835 Figure 3In vivo treatment with MD. Fifteen 6-week-old Balb/c mice were subcutaneously inoculated with 1.5 × 1054T1 tumor cells and divided into 3 treatment groups on day 3 based on equivalent tumor size. Mice were treated with 250 µg microbial derivatives (MD#1) or vehicle control (vehicle #1) in combination with anti-PD-1 (200 µg; clone 29F.1A12) starting on day 3 and continued every other day for a total of 4 injections (black arrows). (A) Tumor measurements were taken every other day using a caliper and volume calculated using the formula: tumor volume = (length x width2) ÷ 2 (B) 2 × 105 splenocytes were co-cultured 1:1 with 4T1 tumor cells in vitro and T cell activation (percent CD8+41BB+) was measured by flow cytometry. Experiment repeated in duplicate, statistical analysis by 2-way ANOVA (*p<0.05, **p<0.01, ***p<0.001, ****p<0.0001).ConclusionsOur results thus far confirm that our proprietary MDs can increase HLA expression on tumor cells, and that this can lead to increased recognition by antigen-specific CTL both in vitro and in vivo. This suggests that MDs could be explored in combination with ICIs to enhance clinical anti-cancer immune responses.

Melatonin modifies tumor hypoxia and metabolism by inhibiting HIF-1α and energy metabolic pathway in the in vitro and in vivo models of breast cancer

2019 ◽  
Vol 2 (4) ◽  
pp. 83-98 ◽  
Author(s):  
André De Lima Mota ◽  
Bruna Vitorasso Jardim-Perassi ◽  
Tialfi Bergamin De Castro ◽  
Jucimara Colombo ◽  
Nathália Martins Sonehara ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Glucose Metabolism ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Carbonic Anhydrases ◽  
In Vivo Models ◽  
Ca Ix ◽  
Gene And Protein Expression

Breast cancer is the most common cancer among women and has a high mortality rate. Adverse conditions in the tumor microenvironment, such as hypoxia and acidosis, may exert selective pressure on the tumor, selecting subpopulations of tumor cells with advantages for survival in this environment. In this context, therapeutic agents that can modify these conditions, and consequently the intratumoral heterogeneity need to be explored. Melatonin, in addition to its physiological effects, exhibits important anti-tumor actions which may associate with modification of hypoxia and Warburg effect. In this study, we have evaluated the action of melatonin on tumor growth and tumor metabolism by different markers of hypoxia and glucose metabolism (HIF-1α, glucose transporters GLUT1 and GLUT3 and carbonic anhydrases CA-IX and CA-XII) in triple negative breast cancer model. In an in vitro study, gene and protein expressions of these markers were evaluated by quantitative real-time PCR and immunocytochemistry, respectively. The effects of melatonin were also tested in a MDA-MB-231 xenograft animal model. Results showed that melatonin treatment reduced the viability of MDA-MB-231 cells and tumor growth in Balb/c nude mice (p <0.05). The treatment significantly decreased HIF-1α gene and protein expression concomitantly with the expression of GLUT1, GLUT3, CA-IX and CA-XII (p <0.05). These results strongly suggest that melatonin down-regulates HIF-1α expression and regulates glucose metabolism in breast tumor cells, therefore, controlling hypoxia and tumor progression. 

ANTITUMOR EFFECT OF COLLOIDAL SILVER BISILICATE IN EXPERIMENTAL IN VITRO AND IN VIVO STUDIES

2019 ◽  
Vol 65 (5) ◽  
pp. 760-765
Author(s):  
Margarita Tyndyk ◽  
Irina Popovich ◽  
A. Malek ◽  
R. Samsonov ◽  
N. Germanov ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Tumor Growth ◽  
Tumor Cells ◽  
Human Tumor ◽  
Significant Inhibition ◽  
In Vivo Studies ◽  
Ehrlich Carcinoma ◽  
In Vivo Experiments

The paper presents the results of the research on the antitumor activity of a new drug - atomic clusters of silver (ACS), the colloidal solution of nanostructured silver bisilicate Ag6Si2O7 with particles size of 1-2 nm in deionized water. In vitro studies to evaluate the effect of various ACS concentrations in human tumor cells cultures (breast cancer, colon carcinoma and prostate cancer) were conducted. The highest antitumor activity of ACS was observed in dilutions from 2.7 mg/l to 5.1 mg/l, resulting in the death of tumor cells in all studied cell cultures. In vivo experiments on transplanted Ehrlich carcinoma model in mice consuming 0.75 mg/kg ACS with drinking water revealed significant inhibition of tumor growth since the 14th day of experiment (maximally by 52% on the 28th day, p < 0.05) in comparison with control. Subcutaneous injections of 2.5 mg/kg ACS inhibited Ehrlich's tumor growth on the 7th and 10th days of the experiment (p < 0.05) as compared to control.

scholarly journals EphA2 super-enhancer promotes tumor progression by recruiting FOSL2 and TCF7L2 to activate the target gene EphA2

2021 ◽  
Vol 12 (3) ◽  
Author(s):  
Shuang Cui ◽  
Qiong Wu ◽  
Ming Liu ◽  
Mu Su ◽  
ShiYou Liu ◽  
...  
Keyword(s):  
Tumor Progression ◽  
Tumor Cells ◽  
Target Gene ◽  
Super Enhancer ◽  
Proliferation And Metastasis ◽  
Active Transcription ◽  
Hct 116 ◽  
Large Clusters

AbstractSuper-enhancers or stretch enhancers (SEs) consist of large clusters of active transcription enhancers which promote the expression of critical genes that define cell identity during development and disease. However, the role of many super-enhancers in tumor cells remains unclear. This study aims to explore the function and mechanism of a new super-enhancer in various tumor cells. A new super-enhancer that exists in a variety of tumors named EphA2-Super-enhancer (EphA2-SE) was found using multiple databases and further identified. CRISPR/Cas9-mediated deletion of EphA2-SE results in the significant downregulation of its target gene EphA2. Mechanistically, we revealed that the core active region of EphA2-SE comprises E1 component enhancer, which recruits TCF7L2 and FOSL2 transcription factors to drive the expression of EphA2, induce cell proliferation and metastasis. Bioinformatics analysis of RNA-seq data and functional experiments in vitro illustrated that EphA2-SE deletion inhibited cell growth and metastasis by blocking PI3K/AKT and Wnt/β-catenin pathway in HeLa, HCT-116 and MCF-7 cells. Overexpression of EphA2 in EphA2-SE−/− clones rescued the effect of EphA2-SE deletion on proliferation and metastasis. Subsequent xenograft animal model revealed that EphA2-SE deletion suppressed tumor proliferation and survival in vivo. Taken together, these findings demonstrate that EphA2-SE plays an oncogenic role and promotes tumor progression in various tumors by recruiting FOSL2 and TCF7L2 to drive the expression of oncogene EphA2.

scholarly journals Differentiated glioblastoma cells accelerate tumor progression by shaping the tumor microenvironment via CCN1-mediated macrophage infiltration

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Atsuhito Uneda ◽  
Kazuhiko Kurozumi ◽  
Atsushi Fujimura ◽  
Kentaro Fujii ◽  
Joji Ishida ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Progression ◽  
Tumor Cells ◽  
In Silico ◽  
Tumor Tissue ◽  
The Cancer Genome Atlas ◽  
Macrophage Infiltration ◽  
Macrophage Migration

AbstractGlioblastoma (GBM) is the most lethal primary brain tumor characterized by significant cellular heterogeneity, namely tumor cells, including GBM stem-like cells (GSCs) and differentiated GBM cells (DGCs), and non-tumor cells such as endothelial cells, vascular pericytes, macrophages, and other types of immune cells. GSCs are essential to drive tumor progression, whereas the biological roles of DGCs are largely unknown. In this study, we focused on the roles of DGCs in the tumor microenvironment. To this end, we extracted DGC-specific signature genes from transcriptomic profiles of matched pairs of in vitro GSC and DGC models. By evaluating the DGC signature using single cell data, we confirmed the presence of cell subpopulations emulated by in vitro culture models within a primary tumor. The DGC signature was correlated with the mesenchymal subtype and a poor prognosis in large GBM cohorts such as The Cancer Genome Atlas and Ivy Glioblastoma Atlas Project. In silico signaling pathway analysis suggested a role of DGCs in macrophage infiltration. Consistent with in silico findings, in vitro DGC models promoted macrophage migration. In vivo, coimplantation of DGCs and GSCs reduced the survival of tumor xenograft-bearing mice and increased macrophage infiltration into tumor tissue compared with transplantation of GSCs alone. DGCs exhibited a significant increase in YAP/TAZ/TEAD activity compared with GSCs. CCN1, a transcriptional target of YAP/TAZ, was selected from the DGC signature as a candidate secreted protein involved in macrophage recruitment. In fact, CCN1 was secreted abundantly from DGCs, but not GSCs. DGCs promoted macrophage migration in vitro and macrophage infiltration into tumor tissue in vivo through secretion of CCN1. Collectively, these results demonstrate that DGCs contribute to GSC-dependent tumor progression by shaping a mesenchymal microenvironment via CCN1-mediated macrophage infiltration. This study provides new insight into the complex GBM microenvironment consisting of heterogeneous cells.

scholarly journals Promising potential of [177Lu]Lu-DOTA-folate to enhance tumor response to immunotherapy—a preclinical study using a syngeneic breast cancer model

2020 ◽  
Author(s):  
Patrycja Guzik ◽  
Klaudia Siwowska ◽  
Hsin-Yu Fang ◽  
Susan Cohrs ◽  
Peter Bernhardt ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Survival Time ◽  
Tumor Cells ◽  
Median Survival ◽  
Breast Tumor ◽  
Median Survival Time ◽  
Therapy Outcome ◽  
Minor Effect

Abstract Purpose It was previously demonstrated that radiation effects can enhance the therapy outcome of immune checkpoint inhibitors. In this study, a syngeneic breast tumor mouse model was used to investigate the effect of [177Lu]Lu-DOTA-folate as an immune stimulus to enhance anti-CTLA-4 immunotherapy. Methods In vitro and in vivo studies were performed to characterize NF9006 breast tumor cells with regard to folate receptor (FR) expression and the possibility of tumor targeting using [177Lu]Lu-DOTA-folate. A preclinical therapy study was performed over 70 days with NF9006 tumor-bearing mice that received vehicle only (group A); [177Lu]Lu-DOTA-folate (5 MBq; 3.5 Gy absorbed tumor dose; group B); anti-CTLA-4 antibody (3 × 200 μg; group C), or both agents (group D). The mice were monitored regarding tumor growth over time and signs indicating adverse events of the treatment. Results [177Lu]Lu-DOTA-folate bound specifically to NF9006 tumor cells and tissue in vitro and accumulated in NF9006 tumors in vivo. The treatment with [177Lu]Lu-DOTA-folate or an anti-CTLA-4 antibody had only a minor effect on NF9006 tumor growth and did not substantially increase the median survival time of mice (23 day and 19 days, respectively) as compared with untreated controls (12 days). [177Lu]Lu-DOTA-folate sensitized, however, the tumors to anti-CTLA-4 immunotherapy, which became obvious by reduced tumor growth and, hence, a significantly improved median survival time of mice (> 70 days). No obvious signs of adverse effects were observed in treated mice as compared with untreated controls. Conclusion Application of [177Lu]Lu-DOTA-folate had a positive effect on the therapy outcome of anti-CTLA-4 immunotherapy. The results of this study may open new perspectives for future clinical translation of folate radioconjugates.

scholarly journals BSCI-12. Inhibition of melanoma brain metastasis by targeting miR-146a

2021 ◽  
Vol 3 (Supplement_3) ◽  
pp. iii3-iii3
Author(s):  
Jiwei Wang ◽  
Emma Rigg ◽  
Taral R Lunavat ◽  
Wenjing Zhou ◽  
Zichao Feng ◽  
...  
Keyword(s):  
Brain Metastasis ◽  
Tumor Cells ◽  
Cell Lines ◽  
Western Blots ◽  
Cell Growth And Migration ◽  
Human Astrocytes ◽  
And Migration ◽  
The Brain

Abstract Background Melanoma has the highest propensity of any cancer to metastasize to the brain, with late-stage patients developing brain metastasis (MBM) in 40% of cases. Survival of patients with MBM is around 8 months with current therapies, illustrating the need for new treatments. MBM development is likely caused by molecular interactions between tumor cells and the brain, constituting the brain metastatic niche. miRNAs delivered by exosomes released by the primary tumor cells may play a role in niche establishment, yet the mechanisms are poorly understood. Here, the aim was to identify miRNAs released by exosomes from melanomas, which may be important in niche establishment and MBM progression. Materials and Methods miRNAs from exosomes collected from human astrocytes, melanocytes, and MBM cell lines were profiled to determine differential expression. Functional in vitro validation was performed by cell growth and migration assays, cytokine arrays, qPCR and Western blots. Functional in vivo studies were performed after miR knockdown in MBM cell lines. An in silico docking study was performed to determine drugs that potentially inhibit transcription of miR-146a to impede MBM development. Results miR-146a was the most upregulated miRNA in exosomes from MBM cells and was highly expressed in human and animal MBM samples. miR-146a mimics activated human astrocytes, shown by increased proliferation and migration, elevated expression of GFAP in vitro and in mouse brain tumor samples, and increased cytokine production. In animal studies, knockdown of miR-146a in MBM cells injected intracardially into mice reduced BM burden and increased animal survival. Based on the docking studies, deserpidine was found to be an effective inhibitor of MBM growth in vitro and in vivo. Conclusions MiR-146a may play an important role in MBM development, and deserpidine is a promising candidate for clinical use.

scholarly journals Highly Differentiated Anti-CD47 Antibody, AO-176, Potently Inhibits Hematologic Malignancies Alone and in Combination

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1844-1844
Author(s):  
John Richards ◽  
Myriam N Bouchlaka ◽  
Robyn J Puro ◽  
Ben J Capoccia ◽  
Ronald R Hiebsch ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Combination Therapy ◽  
Tumor Growth ◽  
Growth Inhibition ◽  
Tumor Cells ◽  
Tumor Growth Inhibition ◽  
Employment Equity ◽  
Equity Ownership

AO-176 is a highly differentiated, humanized anti-CD47 IgG2 antibody that is unique among agents in this class of checkpoint inhibitors. AO-176 works by blocking the "don't eat me" signal, the standard mechanism of anti-CD47 antibodies, but also by directly killing tumor cells. Importantly, AO-176 binds preferentially to tumor cells, compared to normal cells, and binds even more potently to tumors in their acidic microenvironment (low pH). Hematological neoplasms are the fourth most frequently diagnosed cancers in both men and women and account for approximately 10% of all cancers. Here we describe AO-176, a highly differentiated anti-CD47 antibody that potently targets hematologic cancers in vitro and in vivo. As a single agent, AO-176 not only promotes phagocytosis (15-45%, EC50 = 0.33-4.1 µg/ml) of hematologic tumor cell lines (acute myeloid leukemia, non-Hodgkin's lymphoma, multiple myeloma, and T cell leukemia) but also directly targets and kills tumor cells (18-46% Annexin V positivity, EC50 = 0.63-10 µg/ml) in a non-ADCC manner. In combination with agents targeting CD20 (rituximab) or CD38 (daratumumab), AO-176 mediates enhanced phagocytosis of lymphoma and multiple myeloma cell lines, respectively. In vivo, AO-176 mediates potent monotherapy tumor growth inhibition of hematologic tumors including Raji B cell lymphoma and RPMI-8226 multiple myeloma xenograft models in a dose-dependent manner. Concomitant with tumor growth inhibition, immune cell infiltrates were observed with elevated numbers of macrophage and dendritic cells, along with increased pro-inflammatory cytokine levels in AO-176 treated animals. When combined with bortezomib, AO-176 was able to elicit complete tumor regression (100% CR in 10/10 animals treated with either 10 or 25 mg/kg AO-176 + 1 mg/kg bortezomib) with no detectable tumor out to 100 days at study termination. Overall survival was also greatly improved following combination therapy compared to animals treated with bortezomib or AO-176 alone. These data show that AO-176 exhibits promising monotherapy and combination therapy activity, both in vitro and in vivo, against hematologic cancers. These findings also add to the previously reported anti-tumor efficacy exhibited by AO-176 in solid tumor xenografts representing ovarian, gastric and breast cancer. With AO-176's highly differentiated MOA and binding characteristics, it may have the potential to improve upon the safety and efficacy profiles relative to other agents in this class. AO-176 is currently being evaluated in a Phase 1 clinical trial (NCT03834948) for the treatment of patients with select solid tumors. Disclosures Richards: Arch Oncology Inc.: Employment, Equity Ownership, Other: Salary. Bouchlaka:Arch Oncology Inc.: Consultancy, Equity Ownership. Puro:Arch Oncology Inc.: Employment, Equity Ownership. Capoccia:Arch Oncology Inc.: Employment, Equity Ownership. Hiebsch:Arch Oncology Inc.: Employment, Equity Ownership. Donio:Arch Oncology Inc.: Employment, Equity Ownership. Wilson:Arch Oncology Inc.: Employment, Equity Ownership. Chakraborty:Arch Oncology Inc.: Employment, Equity Ownership. Sung:Arch Oncology Inc.: Employment, Equity Ownership. Pereira:Arch Oncology Inc.: Employment, Equity Ownership.

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