GCS-100 Induces Apoptosis of Acute Myeloid Leukemia Cells By Disrupting Galectin-Mediated Survival Signaling

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 904-904
Author(s):  
Richard E. Davis ◽  
Vivian R Ruvolo ◽  
Zhiqiang Wang ◽  
Wencai Ma ◽  
Wendy D. Schober ◽  
...  

Abstract Galectins are a family of b-galactoside binding proteins with effects on cell adhesion, apoptosis, cell cycle, and mRNA processing. Galectin-3 (LGALS3) is unique among galectins by having an N terminal region of roughly 130 amino acids that allows for multimerization and binding to other proteins independent of carbohydrate binding. In addition to promoting BCL2 gene expression and mitochondrial integrity, LGALS3 (along with LGALS1) positively regulates RAS signaling and thus stabilizes survival proteins dependent on ERK phosphorylation such as MCL-1. The pro-survival functions of LGALS3 and other galectins suggest that their targeting could be therapeutic for cancers including AML. Indeed, LGALS3 expression is a predictor of poor prognosis in acute myeloid leukemia (AML), as reported by Cheng and colleagues (Blood 2013) for patients with non-M3 AML and CN-AML. The modified pectin GCS-100 (La Jolla Pharmaceutical, San Diego, CA), now in a Phase II clinical trial for chronic kidney disease, binds and blocks the function of LGALS3. We report that GCS-100 suppresses the growth of AML cell lines OCI-AML3, THP-1, and HL60 in vitro as a single agent, at doses under the 250 ug/mL (i.e., within clinically-achievable concentrations). Short-term treatment of cells (i.e., < 6 hr) potently suppressed phosphorylation of AKT and ERK and reduced expression of BCL2 and MCL-1. Because LGALS3 positively regulates anti-apoptotic BCL2 family members, the Raz group has suggested targeting galectins to enhance efficacy of BH3 mimetic drugs (Harazano et al Cancer Metastasis Review 2013). We found that GCS-100 potently synergized with ABT-737 to kill OCI-AML3 cells: while 1 uM ABT-737 or 125 ug/mL GCS-100 reduced total viable cells by ~ 30% and induced apoptosis in < 20% of cells after 48 hr as single agents, their combination at those doses and time point reduced viable cells by ~ 94% and induced apoptosis in ~ 70% of cells. Suppression of LGALS3 by lentiviral shRNA reduced BCL2 gene expression as determined by qRT-PCR and augmented killing with ABT-737. Lentiviral suppression of LGALS3 protected cells from GCS-100 at doses of 250 ug/mL but reduction of the galectin failed to protect cells from higher doses of the drug (i.e., 500 ug/mL). This result suggests other galectins are likely inhibited at higher doses of the agent. We used gene expression profiling (GEP) on Illumina HT12v4 human whole-genome arrays to assess more broadly the molecular effects of inhibiting galectins in AML cell lines OCI-AML3 and THP-1 treated with 250 ug/mL or 500 ug/ml GCS-100 for 24 hr. Data were analyzed by Gene Set Enrichment Analysis (GSEA) using gene sets from the Molecular Signatures Database (www.broadinstitute.org/gsea/msigdb/). GSEA suggested that GCS-100 promotes differentiation and inhibits genes associated with proliferation. Multiple upregulated gene sets suggest that there may be a release of a differentiation block as a result of GCS-100 treatment. Furthermore, two gene sets suggest that GCS-100 behaves similar to a GSK3 inhibitor: Known pathways regulated by GSK3 in hematopoietic stem cells are mTOR and Wnt/beta Catenin. Inhibition of Wnt/beta Catenin can release a differentiation block. Consistent with GCS-100 promoting cell differentiation, lentiviral shRNA reduced LGALS3 protein > 90% in THP-1 cells and increased CD11b expression, suggesting increased differentiation, compared to cells with control shRNA. GCS-100 was tested in an in vitro model of the bone marrow microenvironment using BM-derived mesenchymal stromal cell (MSC). MSC can protect leukemia cells from a variety of clinically relevant chemotherapy drugs including AraC. GCS-100 was effective at killing AML cells despite the presence of MSC. Both THP-1 and OCI-AML3 cells exhibited > 80% and > 60% reduction of viable cells, respectively, despite the presence of MSC when treated with 250 ug/mL GCS-100 for 72 hours. In addition, GCS-100 was found to block adhesion of OCI-AML3 cells to MSC suggesting that GCS-100 could be effective in mobilizing AML cells. In summary, our findings suggest that GCS-100 can induce apoptosis in AML cells as a single agent or in combination with the BH3 mimetic ABT-737. The agent is effective even in the presence of MSC suggesting it could be efficacious in the leukemia niche. These findings suggest GCS-100 could be effective for AML therapy. Disclosures Rolke: La Jolla Pharmaceutical Company: Employment. Tidmarsh:La Jolla Pharmaceutical Company: Employment.

2021 ◽  
Vol 22 (12) ◽  
pp. 6322
Author(s):  
Marinela Bostan ◽  
Mirela Mihaila ◽  
Georgiana Gabriela Petrica-Matei ◽  
Nicoleta Radu ◽  
Razvan Hainarosie ◽  
...  

In head and neck cancers, the effectiveness of cisplatin (CisPt) treatment is limited by its toxicity, especially when higher doses are necessary, and the possible occurrence of cisplatin resistance. This study evaluated the effects of resveratrol (RSV) on the expression of different genes involved in the response of human tumor cells (FaDu, PE/CA-PJ49) to cisplatin therapy. Our results revealed that RSV induced apoptosis amplification in both FaDu and PE/CA-PJ49 cells and modulated the expression of specific genes differently than in normal HaCaT cells. In FaDu cells, combined CisPt + RSV treatment induced an increase in apoptosis, which was associated with an increase in c-MYC and TP53 and a decrease in BCL-2 expression. While CisPt + RSV treatment induced apoptosis in PE/CA-PJ49 cells by inhibition of BCL-2 associated with high levels of MDM-2 and subsequently led to inhibition of TP53 gene expression. Decreased c-MYC expression in PE/CA-PJ49 treated with CisPt + RSV was accompanied by cell cycle blockage in G0/G1 phase. In conclusion, RSV influences tumor cell response to CisPt by inducing apoptosis and modulating gene expression. In addition, in normal HaCaT cells, RSV was able to reduce the harmful effects of CisPt.


2016 ◽  
Vol 44 (03) ◽  
pp. 637-661 ◽  
Author(s):  
Yin-Wen Shiue ◽  
Chi-Cheng Lu ◽  
Yu-Ping Hsiao ◽  
Ching-Lung Liao ◽  
Jing-Pin Lin ◽  
...  

Casticin, a polymethoxyflavone occurring in natural plants, has been shown to have anticancer activities. In the present study, we aims to investigate the anti-skin cancer activity of casticin on melanoma cells in vitro and the antitumor effect of casticin on human melanoma xenografts in nu/nu mice in vivo. A flow cytometric assay was performed to detect expression of viable cells, cell cycles, reactive oxygen species production, levels of [Formula: see text] and caspase activity. A Western blotting assay and confocal laser microscope examination were performed to detect expression of protein levels. In the in vitro studies, we found that casticin induced morphological cell changes and DNA condensation and damage, decreased the total viable cells, and induced G2/M phase arrest. Casticin promoted reactive oxygen species (ROS) production, decreased the level of [Formula: see text], and promoted caspase-3 activities in A375.S2 cells. The induced G2/M phase arrest indicated by the Western blotting assay showed that casticin promoted the expression of p53, p21 and CHK-1 proteins and inhibited the protein levels of Cdc25c, CDK-1, Cyclin A and B. The casticin-induced apoptosis indicated that casticin promoted pro-apoptotic proteins but inhibited anti-apoptotic proteins. These findings also were confirmed by the fact that casticin promoted the release of AIF and Endo G from mitochondria to cytosol. An electrophoretic mobility shift assay (EMSA) assay showed that casticin inhibited the NF-[Formula: see text]B binding DNA and that these effects were time-dependent. In the in vivo studies, results from immuno-deficient nu/nu mice bearing the A375.S2 tumor xenograft indicated that casticin significantly suppressed tumor growth based on tumor size and weight decreases. Early G2/M arrest and mitochondria-dependent signaling contributed to the apoptotic A375.S2 cell demise induced by casticin. In in vivo experiments, A375.S2 also efficaciously suppressed tumor volume in a xenotransplantation model. Therefore, casticin might be a potential therapeutic agent for the treatment of skin cancer in the future.


Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 47-47
Author(s):  
Jessie-F Fecteau ◽  
Ila Bharati ◽  
Morgan O'Hayre ◽  
Tracy Handel ◽  
Thomas J. Kipps ◽  
...  

Abstract Abstract 47 Chronic Lymphocytic Leukemia (CLL) is characterized by an accumulation of mature monoclonal B cells in the blood, secondary lymphoid tissue, and marrow. Despite their accumulation in vivo, CLL cells undergo spontaneous apoptosis in vitro unless rescued by extrinsic factors derived from the leukemia-cell microenvironment. Monocyte-derived Nurse-Like Cells (NLCs) and Marrow Stromal Cells (MSCs), representing the leukemic microenvironment, have been show to sustain CLL cell survival and more importantly to protect CLL cells from drug-induced apoptosis in vitro and possibly in vivo. Such protective niches are thought to prevent current therapies from achieving complete remission in patients. Investigating the mechanism(s) by which cells from the microenvironment promote CLL cell survival, particularly the signaling pathways triggered, will allow for the identification of new therapeutic targets aiming to disrupt these protective interactions. NLCs and MSCs have been shown to produce the chemokine SDF-1 (CXCL12), which can enhance CLL cell survival. We recently found that ZAP-70+ aggressive CLL cells responded by an increased survival to this chemokine, compared to ZAP-70- indolent CLL cells, and that this response was accompanied by the activation of the ERK pathway. Attempting to abrogate this survival pathway, we found that sorafenib (BAY 43–9006, Nexavar) a multi-kinase inhibitor targeting among others Raf kinases and thereby the RAF/MEK/ERK pathway, strongly reduced CLL cell viability in a time and dose dependent manner. A regimen of one single dose of 10uM of sorafenib significantly reduced CLL cell viability to 18+/−10% cells after 48hrs compared to vehicle control (DMSO; 100%; n=5). The daily addition of 1uM sorafenib also significantly decreased CLL cell viability, leading to 31+/−21% and 11+/−5% viable cells after 6 and 7 days respectively, compared to DMSO (n=5). More importantly, our results show that sorafenib induces CLL cell death in the presence of NLCs and MSCs. A single dose of sorafenib (10uM) rapidly decreased the fraction of viable CLL cells overtime, passing from 40+/−16% after 1 day to 10+/−3% after 4 days (n=4) in the context of NLCs and to 25+/−3% after 2 days and 14+/−3% after 4 days in the presence of MSCs, when compared to vehicle control (>80%; n=4). In the presence of NLCs, the 1uM daily regimen also uncovered an increased sensitivity of ZAP-70+ CLL cells to this drug, reducing in 6 days their viability to 13+/−2% (n=4), which approximately half the fraction of viable cells remaining in the ZAP-70- group (40+/−16%; n=7). We next studied sorafenib-mediated cytotoxicity by investigating its impact on the expression of pro-survival molecules. We found that Mcl-1, Bcl-2 and Bcl-xL protein expression was reduced in CLL cells compared to vehicle control, when stimulated with CXCL12 (n=3). In the presence of NLCs and MSCs, only Mcl-1 expression was downregulated, which was also associated with a reduction of the active form of the transcription factor CREB, involved in Mcl-1 expression. Because Mcl-1 expression can be regulated by ERK and AKT pathways, we next investigated if they were abrogated by sorafenib. We indeed found that MEK, ERK, and AKT activation were reduced by this inhibitor compared to vehicle control (n=3). We therefore propose that the cytotoxic effect of sorafenib on CLL cells is due to its interference with at least these two major survival pathways. Since sorafenib caused apoptosis of CLL cells in context of the microenvironment, we reasoned that it might also cause apoptosis of chemotherapy resistant CLL cells. To test this hypothesis, we studied cells from fludarabine-refractory patients. In the presence of NLCs, a single dose of 10uM sorafenib induced a significant reduction in CLL cell viability after 2 days: only 4+/−2% viable cells remained compared to 78+/−12% for the vehicle control (n=4). A comparable observation was made in the presence of MSCs: sorafenib potently induced apoptosis, leaving 12+/−3% live cells after 2 days, compared to vehicle control (71+/−16%; n=4). These results are very promising as they suggest that sorafenib could be an effective novel therapeutic for CLL, affecting the viability of the leukemic cells even in protective niches. Since sorafenib has been approved by the FDA in 2007 for the treatment of advanced hepatocellular carcinoma, a pilot study is currently being planned at UCSD to evaluate the potential of this drug in CLL in vivo. Disclosures: No relevant conflicts of interest to declare.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1847-1847
Author(s):  
Chirag Acharya ◽  
Mike Y Zhong ◽  
Daniel Tannenbaum ◽  
Michelle Chen ◽  
Matt Ma ◽  
...  

Abstract Abstract 1847 Aminopeptidases (AP) are necessary for the growth and development of malignant cells and have a selectively important role in the maintenance of intracellular amino acid (AA) levels in neoplastic cells. CHR2797 is a novel, low nanomolar inhibitor of the M1 family of AP, a group of metalloenzymes containing a central Zn2+ ion. CHR2797 has antiproliferative and apoptotic effects against MM in vitro by inducing the AA deprivation response (AADR). TST, an oral, chronically administered agent with a good safety profile has demonstrated activity in patients with relapsed/refractory AML and is currently under study as part of combination therapy for untreated elderly patients with AML. At the epigenetic regulatory level, Zn-dependent histone deacetylase (HDAC) cause the deacetylation of histone and non-histone cellular proteins which are critical for gene expression, inducing apoptosis and cell cycle arrest in cancer cells. LBH589 (Panobinostat) is an established pan-HDAC inhibitor with potent in vitro anti-cancer activity in many hematological malignancies. The clinical efficacy of Panobinostat is currently being studied in several Phase II/III clinical trials with particular promise seen in the treatment of MM. Here we examined the potential therapeutic effect of CHR2797, alone and with LBH589, against MM cells. Using MTS and CTG assays, CHR2797, at clinically achievable concentrations, decreased survival and proliferation in MM1S and IL-6-dependent ANBL6 cells, in the presence or absence of bone marrow stromal cells following 72 hours incubation. CHR2797 induces apoptosis in MM cells via activation of Caspase 3/7 and 9 but not Caspase 8. Significantly, CHR2797 (10 μM) induced apoptosis in patient MM cells, as seen by % of annexin V and PI from 22 + 1.5% to 39 + 2.3% after 48h incubation. Combined treatment with CHR2797 and LBH589 in MM cells (MM1S, ANBL6, and INA6) further reduced cell viability following 72 hour incubation when compared with CHR2797 treatment alone, as determined by CTG viability luminescent assay. Both drugs together also augmented growth inhibitory effects when compared with single agent alone, after 72 hours incubation followed by MTS assay. Importantly, the combination of both drugs increased caspase 3/7- & 9-mediated apoptosis than CHR2797 alone in these MM cells following 24h-treatment. Cell cycle analysis (CHR2797 at 1μM; LBH589 at 1 nM) showed an increased growth arrest in G0/G1 cells in MM1R cells treated with both drugs versus CHR2797 alone after 24 hours: 68.5±3.3% versus 36±2.5%. Furthermore, CHR2797 inhibited anti-apoptotic protein Mcl-1 in MM1R and U266 MM cells by immunoblottings. Combined treatment with CHR2797 and LBH589 further blocked Mcl-1 when compared with either treatment alone after 24 hours incubation. Together, these results show that the combination of CHR2797 and LBH589 enhanced anti-myeloma effects when compared with either drug alone. This combination, which also has the potential of being without overlapping clinical toxicities, provides a promising novel approach to anti-myeloma therapy. Disclosures: Singer: Cell Therapeutics, Inc: Employment, Equity Ownership. Richardson:Novartis: Membership on an entity's Board of Directors or advisory committees.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 10605-10605
Author(s):  
Kapil N. Bhalla ◽  
Warren Fiskus ◽  
Sunil Sharma ◽  
Stephen Horrigan ◽  
Uma Mudunuru ◽  
...  

10605 Background: The canonical WNT-β-catenin pathway is essential for self-renewal, growth and survivalof AML stem and progenitor cells. Deregulated WNT signaling inhibits degradation of β-catenin, causing increased nuclear translocation and interaction of β-catenin with the TCF/LEF transcription factor, which up regulates cyclin D1, Myc and survivin expression in AML progenitor cells. BC2059 (β-Cat Pharmaceuticals) is a potent, small molecule, anthraquinone oxime-analog, which inhibits WNT-β catenin pathway by promoting the degradation and attenuation of β-catenin levels. Methods: We determined the in vitro anti-AML activity of BC2059 (BC) (250 to 1000 nM) against cultured and primary human AML blast progenitors, as well as evaluated the in vivo anti-AML efficacy of BC in NOD-SCID and NOD-SCID-IL2γ receptor deficient (NSG) mice. Results: BC induced cell cycle G1 phase accumulation and apoptosis (40%) of the cultured OCI-AML3, HL-60 and HEL92.1.7 (HEL) AML cells. BC dose-dependently also induced apoptosis of primary AML versus normal progenitors. Treatment with BC resulted in proteasomal degradation and decline in the nuclear levels of β-catenin, which led to decreased activity of the LEF1/TCF4 transcription factor highlighted by reduced TOP-FLASH luciferase activity in the AML cells. This was associated with reduced protein levels of cyclin D1, MYC and survivin. Co-treatment with BC and the histone deacetylase inhibitor panobinostat (PS) (10 to 20 nM) synergistically induced apoptosis of cultured and primary AML blasts. Following tail vein infusion and establishment of AML by OCI-AML3 or HEL cells in NOD-SCID mice, treatment with BC (5, 10 or 15 mg/kg b.i.w, IV) for three weeks demonstrated improved survival, as compared to the control mice (p <0. 001). Survival was further improved upon co-treatment with BC and PS (5 mg/kg IP, MWF). BC treatment (5 or 10 mg/kg IV) also dramatically improved survival of NSG mice with established human AML following tail-vein injection of primary AML blasts expressing FLT3 ITD. Mice did not experience any toxicity or weight loss. Conclusions: These findings highlight the notable pre-clinical in vitro and in vivo activity and warrant further development and in vivo testing of BC against human AML.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13569-e13569
Author(s):  
Enrica Marchi ◽  
Matko Kalac ◽  
Danielle Bongero ◽  
Christine McIntosh ◽  
Laura K Fogli ◽  
...  

e13569 Background: CHOP and CHOP-like chemotherapy are the most used regimens for the treatment of peripheral T-cell lymphomas (PTCLs) despite sub-optimal results. Histone deacetylase inhibitors (HDACIs) have shown class activity in PTCLs. The interaction between the HDACIs (depsipeptide (R), belinostat (B), vorinostat (V) and panobinostat (P)) and a DNMT inhibitor (decitabine (D) was investigated in vitro, in vivo and at the molecular level in T-cell lymphoma and leukemia cell lines (H9, HH, P12, PF-382). Methods: For cytotoxicity assays, luminescence cell viability assay was used (CellTiter-Glo). Drug:drug interactions were analyzed with relative risk ratios (RRR) based on the GraphPad software (RRR<1 defining synergism). Apoptosis was assessed by Yo-Pro-1 and propidium iodine followed by FACSCalibur acquisition. Gene expression profiling was analyzed using Illumina Human HT-12 v4 Expression BeadChip microarrays and Gene Spring Software for the analysis. Results: The IC50s for B, R, V, P, D and 5-Azacytidine alone were assessed at 24, 48 and 72 hours. In cytotoxicity assays the combination of D plus B, R, V or P at 72 hours showed synergism in all the cell lines (RRRs 0.0007-0.9). All the cell lines were treated with D, B or R for 72 hours and all the combinations showed significantly more apoptosis than the single drug exposures and controls (RRR < 1). In vivo, HH SCID beige mice were treated i.p. for 3 cycles with the vehicle solution, D or B or their combination at increasing dose. The combination cohort showed statistically significant tumor growth inhibition compared to all the other cohorts. Gene expression analysis revealed differentially expressed genes and modulated pathways for each of the single agent treatment and the combination. The effects of the two drugs were largely different (only 39 genes modified in common). Most of the effects induced by the single agent were maintained in the combination group. Interestingly, 944 genes were modulated uniquely by the combination treatment. Conclusions: The combination of a DNMTI and HDACIs is strongly synergistic in vitro, in vivo and at the molecular level in model of T-cell lymphoma and these data will constitute the basis for a phase I-II clinical trials.


2016 ◽  
Vol 34 (4_suppl) ◽  
pp. 558-558 ◽  
Author(s):  
Michael Sangmin Lee ◽  
Benjamin Garrett Vincent ◽  
Autumn Jackson McRee ◽  
Hanna Kelly Sanoff

558 Background: Different immune cell infiltrates into colorectal cancer (CRC) tumors are associated with different prognoses. Tumor-associated macrophages contribute to immune evasion and accelerated tumor progression. Conversely, tumor infiltrating lymphocytes at the invasive margin of CRC liver metastases are associated with improved outcomes with chemotherapy. Cetuximab is an IgG1 monoclonal antibody against epidermal growth factor receptor (EGFR) and stimulates antibody-dependent cellular cytotoxicity (ADCC) in vitro. However, it is unclear in humans if response to cetuximab is modulated by the immune response. We hypothesized that different immune patterns detected in gene expression profiles of CRC metastases are associated with different responses to cetuximab. Methods: We retrieved gene expression data from biopsies of metastases from 80 refractory CRC patients treated with cetuximab monotherapy (GEO GSE5851). Samples were dichotomized by cetuximab response as having either disease control (DC) or progressive disease (PD). We performed gene set enrichment analysis (GSEA) with GenePattern 3.9.4 using gene sets of immunologic signatures obtained from the Molecular Signatures Database v5.0. Results: Among the 68 patients with response annotated, 25 had DC and 43 had PD. In the PD cohort, 59/1910 immunologic gene sets had false discovery rate (FDR) < 0.1. Notably, multiple gene sets upregulated in monocyte signatures were associated with PD. Also, gene sets consistent with PD1-ligated T cells compared to control activated T cells (FDR = 0.052) or IL4-treated CD4 T cells compared to controls (FDR = 0.087) were associated with PD. Conclusions: Cetuximab-resistant patients tended to have baseline increased expression of gene signatures reflective of monocytic infiltrates, consistent with also having increased expression of the IL4-treated T-cell signature. Cetuximab resistance was also associated with increased expression of the PD1-ligated T cell signature. These preliminary findings support further evaluation of the effect of differential immune infiltrates in prognosis of metastatic CRC treated with cetuximab.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 768-768 ◽  
Author(s):  
Bing Z Carter ◽  
Po Yee Mak ◽  
Wenjing Tao ◽  
Mark Warmoes ◽  
Philip L Lorenzi ◽  
...  

Abstract Mcl-1 and Bcl-2 are two major anti-apoptotic Bcl-2 proteins frequently overexpressed in malignant cells. They cooperatively support cell survival and are associated with therapy resistance. ABT-199 (venetoclax), a highly selective Bcl-2 inhibitor, showed potent preclinical activity but limited clinical efficacy in AML as a single agent. Mcl-1 is induced by and a major resistance factor to ABT-199. Mcl-1 was recently found to also positively regulate mitochondrial oxidative phosphorylation that induces cancer stem cells and promotes chemoresistance. Mcl-1 is essential for the development of AML and for the survival of AML cells and stem cells. Increased mitochondrial oxidative phosphorylation has been demonstrated in these cells. First we found that Mcl-1 overexpressing (OE)/knockdown (KD) AML cells were markedly more resistant/sensitive to ABT-199 than were corresponding control cells, supporting the notion of Mcl-1 as a resistance factor to ABT-199. Inhibition of Mcl-1 by the selective Mcl-1 inhibitor AZD5991 or the CDK9 inhibitor AZD4573, which down-regulates short-lived proteins such as Mcl-1, induced apoptosis and showed strong synergy when combined with ABT-199 in AML cell lines, primary AML blasts, and stem/progenitor cells from patients. Importantly, combinations of AZD5991 or AZD4573 with ABT-199 synergistically induced apoptosis in OCI-AML3 and Mcl-1 OE cells intrinsically resistant to ABT-199 and in AML cell lines and primary patient cells with acquired resistance to ABT-199. Although OE/KD Mcl-1 in AML cells did not show obvious alterations in baseline cell viability, NSGS mice harboring Mcl-1 OE/KD OCI-AML3 cells survived significantly shorter/longer than those transplanted with control cells, supporting additional, non-apoptogenic functions of Mcl-1 in AML. We observed that genetic modulation of Mcl-1 alters cellular mitochondrial respiration and ROS levels. AML cells with Mcl-1 OE/KD increased/decreased O2 consumption and mitochondrial ATP and ROS generation. Consistent with this finding, inhibition of Mcl-1 by AZD5991 or AZD4573 decreased O2 consumption and ATP generation in AML cells and also in MV4-11 cells with acquired ABT-199 resistance. Mass spectrometry-based stable isotope tracing experiments using 1,2-13C-glucose showed that both genetic and pharmacological inhibition of Mcl-1 decreased flux of glucose carbon through glycolysis, the TCA cycle, and the pentose phosphate pathway, suggesting a role for Mcl-1 in cellular respiration and redox metabolism. To further assess the efficacy of combined Mcl-1 and Bcl-2 inhibition in primary AML cells resistant to ABT-199, we developed a PDX model using cells from an AML patient who initially responded to ABT-199/demethylating agent and then relapsed. NSGS mice engrafted with these PDX cells were treated with ABT-199 (50 mg/kg, oval gavage qd), AZD5991 (60 mg/kg, i.v. weekly), AZD4573 (15 mg/kg, i.p. bid with 2 h interval for two consequent days/week), ABT-199+AZD5991, or ABT-199+AZD4573 for 6 wks. Flow cytometric analysis of circulating human CD45+ cells on day 18 of therapy showed that each agent significantly decreased leukemia burden and that the combinations were significantly more effective (P<0.01) than each single agent. CyTOF analysis of BM cells (day 25) showed that both combinations markedly reduced (P<0.001) human CD45+ cells and, more importantly, human CD34+CD38+/CD38- and CD34+CD38+/CD38-CD123+ cells. Those combination treatments also decreased Mcl-1, Bcl-2, b-catenin, c-Myc, and FAK protein expression in CD34+CD38-CD123+ cells. Interestingly, AZD5991, AZD4573, or their combinations with ABT-199 greatly decreased CXCR4 in all cell populations. Ultimately, each single agent only marginally prolonged survival, whereas ABT-199+AZD4573 and even more so ABT-199+AZD5991 markedly improved survival in this highly ABT-199 resistant PDX model (Fig). Conclusion: we demonstrate that Mcl-1 has metabolic functions in AML and that inhibition of Mcl-1 enhances ABT-199 apoptogenic activity and overcomes intrinsic and acquired ABT-199 resistance in vitro and in vivo in a PDX murine model of AML, suggesting that inhibition of Mcl-1 improves the efficacy of ABT-199, and overcomes established resistance to Bcl-2 inhibition. Suppressing metabolic activity and CXCR4 inhibition may also contribute to the efficacy of this combination against AML stem cells in the BM microenvironment. Figure. Figure. Disclosures Carter: AstraZeneca: Research Funding; novartis: Research Funding. Lorenzi:Erytech Pharma: Consultancy; NIH: Patents & Royalties. Cidado:AstraZeneca: Employment, Equity Ownership. Drew:AstraZeneca: Employment. Andreeff:AstraZeneca: Research Funding.


2021 ◽  
Author(s):  
Jolet Y. Mimpen ◽  
Mathew J. Baldwin ◽  
Adam P. Cribbs ◽  
Martin Philpott ◽  
Andrew J. Carr ◽  
...  

AbstractIncreased interleukin (IL)-17A has been identified in joints affected by osteoarthritis (OA), but it is unclear how IL-17A, and its family members IL-17AF and IL-17F, can contribute to human OA pathophysiology. Therefore, we aimed to evaluate the gene expression and signalling pathway activation effects of the different IL-17 family members in fibroblasts derived from cartilage and synovium of patients with end-stage knee OA. Immunohistochemistry staining confirmed that IL-17 receptors A (IL-17RA) and IL-17RC are expressed in end-stage OA-derived cartilage and synovium. Chondrocytes and synovial fibroblasts derived from end-stage OA patients were treated with IL-17A, IL-17AF, or IL-17F, and gene expression was assessed with bulk RNA-Seq. Hallmark pathway analysis showed that IL-17 cytokines regulated several OA pathophysiology-related pathways including immune-, angiogenesis-, and complement-pathways in both chondrocytes and synovial fibroblasts derived from end-stage OA patients. While overall IL-17A induced the strongest transcriptional response, followed by IL-17AF and IL-17F, not all genes followed this pattern. Disease-Gene Network analysis revealed that IL-17A-related changes in gene expression in these cells are associated with experimental arthritis, knee arthritis, and musculoskeletal disease gene-sets. Western blot analysis confirmed that IL-17A significantly activates p38 and p65 NF-κB. Incubation of chondrocytes and synovial fibroblasts with IL-17A antibody secukinumab significantly inhibited IL-17A-induced gene expression. In conclusion, the association of IL-17-induced transcriptional changes with arthritic gene-sets supports a role for IL-17A in OA pathophysiology. Therefore, secukinumab could be investigated as a potential therapeutic option in OA patients.


2020 ◽  
Author(s):  
Xiaomei Lei ◽  
Zhijun Feng ◽  
Xiaojun Wang ◽  
Xiaodong He

Abstract Background. Exploring alterations in the host transcriptome following SARS-CoV-2 infection is not only highly warranted to help us understand molecular mechanisms of the disease, but also provide new prospective for screening effective antiviral drugs, finding new therapeutic targets, and evaluating the risk of systemic inflammatory response syndrome (SIRS) early.Methods. We downloaded three gene expression matrix files from the Gene Expression Omnibus (GEO) database, and extracted the gene expression data of the SARS-CoV-2 infection and non-infection in human samples and different cell line samples, and then performed gene set enrichment analysis (GSEA), respectively. Thereafter, we integrated the results of GSEA and obtained co-enriched gene sets and co-core genes in three various microarray data. Finally, we also constructed a protein-protein interaction (PPI) network and molecular modules for co-core genes and performed Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis for the genes from modules to clarify their possible biological processes and underlying signaling pathway. Results. A total of 11 co-enriched gene sets were identified from the three various microarray data. Among them, 10 gene sets were activated, and involved in immune response and inflammatory reaction. 1 gene set was suppressed, and participated in cell cycle. The analysis of molecular modules showed that 2 modules might play a vital role in the pathogenic process of SARS-CoV-2 infection. The KEGG enrichment analysis showed that genes from module one enriched in signaling pathways related to inflammation, but genes from module two enriched in signaling of cell cycle and DNA replication. Particularly, necroptosis signaling, a newly identified type of programmed cell death that differed from apoptosis, was also determined in our findings. Additionally, for patients with SARS-CoV-2 infection, genes from module one showed a relatively high-level expression while genes from module two showed low-level. Conclusions. We identified two molecular modules were used to assess severity and predict the prognosis of the patients with SARS-CoV-2 infection. In addition, these results provide a unique opportunity to explore more molecular pathways as new potential targets on therapy in COVID 19.


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