CC Chemokine Ligand 17 Promoted Cell Metastasis via Tumor Necrosis Factorα/Nuclear Factor Kappa-B Signaling Pathway

Hepatocellular carcinoma (HCC) consist in a proinflammatory tumor environment that is characterized by the presence of many chemokines and cytokines. Expression of CCL17 associated with diagnoses and poor prognosis in different cancers. There are few investigations indicated the relationship between CCL17 and HCC. Thus, this study aims to investigate the role of CCL17 in HCC progression. qRT-PCR and Western Blot were performed to detect expression of CCL17 in HCC cell lines and normal hepatocyte. Elisa was used to determine TNFα, IL-6 and IL-1β. Wound-healing assay and Transwell assay were performed to assed cell metastasis. CCL17 signaling was examined utilizing Western Blot. Here, we showed that CCL17 levels markedly increased in HCC cell lines. At the same time, TNFα, IL-6 and IL-1 β were increased time-dependent after treating human recombinant CCL17 protein. Cell metastasis was significantly promoted by CCL17 while TNFa inhibitor (Lenalidomide) reversed the effects of CCL17. NF-κB signaling pathway was activated by CCL17 and TNFα inhibitor suppressed the effects of CCL17. In conclusion, CCL17 promoted cell metastasis via TNFα/NF-κB signaling pathway. CCL17 may be a potential biomarker for HCC progression.

Download Full-text

Hsa_circ_0005273 facilitates breast cancer tumorigenesis by regulating YAP1-hippo signaling pathway

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-021-01830-z ◽

2021 ◽

Vol 40 (1) ◽

Author(s):

Xuehui Wang ◽

Changle Ji ◽

Jiashu Hu ◽

Xiaochong Deng ◽

Wenfang Zheng ◽

...

Keyword(s):

Breast Cancer ◽

Signaling Pathway ◽

Cell Lines ◽

Luciferase Reporter ◽

Circular Rnas ◽

Hippo Signaling ◽

Hippo Signaling Pathway ◽

Potential Biomarker

Abstract Background Circular RNAs (circRNAs), a novel class of endogenous RNAs, have shown to participate in the development of breast cancer (BC). Hsa_circ_0005273 is a circRNA generated from several exons of PTK2. However, the potential functional role of hsa_circ_0005273 in BC remains largely unknown. Here we aim to evaluate the role of hsa_circ_0005273 in BC. Methods The expression level of hsa_circ_0005273 and miR-200a-3p were examined by RT-qPCR in BC tissues and cell lines. The effect of knocking down hsa_circ_0005273 in BC cell lines were evaluated by examinations of cell proliferation, migration and cell cycle. In addition, xenografts experiment in nude mice were performed to evaluate the effect of hsa_circ_0005273 in BC. RNA immunoprecipitation assay, RNA probe pull-down assay, luciferase reporter assay and fluorescence in situ hybridization were conducted to confirm the relationship between hsa_circ_0005273, miR-200a-3p and YAP1. Results Hsa_circ_0005273 is over-expressed in BC tissues and cell lines, whereas miR-200a-3p expression is repressed. Depletion of hsa_circ_0005273 inhibited the progression of BC cells in vitro and in vivo, while overexpression of hsa_circ_0005273 exhibited the opposite effect. Importantly, hsa_circ_0005273 upregulated YAP1 expression and inactivated Hippo pathway via sponging miR-200a-3p to promote BC progression. Conclusions Hsa_circ_0005273 regulates the miR-200a-3p/YAP1 axis and inactivates Hippo signaling pathway to promote BC progression, which may become a potential biomarker and therapeutic target.

Download Full-text

Silence of long non-coding RNA KCNQ1OT1 inhibits the proliferation, migration and invasion of hepatocellular carcinoma cells through PI3K/AKT signaling pathway

10.21203/rs.3.rs-21344/v1 ◽

2020 ◽

Author(s):

Hongliang Mei ◽

Zhiguo Yu ◽

Guanqi Zhang ◽

Zhiyuan Huang ◽

Hanjun Li ◽

...

Keyword(s):

Hepatocellular Carcinoma ◽

Signaling Pathway ◽

Cell Lines ◽

Negative Impact ◽

Akt Signaling ◽

Cell Counting ◽

Migration And Invasion ◽

Akt Signaling Pathway ◽

Potential Biomarker

Abstract Background: KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) has been reported to be associated with hepatocellular carcinoma (HCC), which is considered as one of the most common cancers worldwide. However, the mechanism of action of KCNQ1OT1 in human HCC has not been fully explained. In this study, we aimed to explore the functional role and the potential mechanism of KCNQ1OT1 in human HCC.Methods: First, we analyzed the expression levels of KCNQ1OT1 in HCC tissues in starBase database and detected the expression of KCNQ1OT1 in HCC cell lines by quantitative real-time polymerase chain reaction assays. Next, we analyzed the role of KCNQ1OT1 in migration, invasion and proliferation of HCC by scratch wound healing, transwell and cell counting kit-8 assays. Finally, we analyzed the potential interrelationship between KCNQ1OT1 and PI3K/AKT signaling pathway through western blot assays.Results: Based on bioinformatics analyses, we found that KCNQ1OT1 was highly expressed in HCC tissues and its high expression was associated with a poor prognosis in HCC patients. We also confirmed an abnormal increase in the expression of KCNQ1OT1 in HCC cell lines. KCNQ1OT1 knockdown was found to have a negative impact on proliferation, migration and invasion of HCC cells. In addition, interference with the expression of KCNQ1OT1 reduced the phosphorylation level of AKT and the protein level of PI3K, indicating the association of KCNQ1OT1 with the PI3K/AKT signaling pathway.Conclusions: Collectively, this study confirmed the important role of KCNQ1OT1 in promoting HCC growth and revealed the inhibitory effect of KCNQ1OT1 on the PI3K/AKT signaling pathway. This work may contribute to a better understanding of HCC progression and provide a potential biomarker for HCC.

Download Full-text

The tRNA-derived fragment 5026a inhibits the proliferation of gastric cancer cells by regulating the PTEN/PI3K/AKT signaling pathway

Stem Cell Research & Therapy ◽

10.1186/s13287-021-02497-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Linwen Zhu ◽

Zhe Li ◽

Xiuchong Yu ◽

Yao Ruan ◽

Yijing Shen ◽

...

Keyword(s):

Gastric Cancer ◽

Cell Cycle ◽

Cancer Cells ◽

Signaling Pathway ◽

Cell Lines ◽

Akt Signaling ◽

Akt Signaling Pathway ◽

Gastric Cancer Cells ◽

Qrt Pcr

Abstract Background Recently, tRNA-derived fragments (tRFs) have been shown to serve important biological functions. However, the role of tRFs in gastric cancer has not been fully elucidated. This study aimed to identify the tumor suppressor role of tRF-5026a (tRF-18-79MP9P04) in gastric cancer. Methods Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was first used to detect tRF-5026a expression levels in gastric cancer tissues and patient plasma. Next, the relationship between tRF-5026a levels and clinicopathological features in gastric cancer patients was assessed. Cell lines with varying tRF-5026a levels were assessed by measuring tRF-5026a using qRT-PCR. After transfecting cell lines with a tRF-5026a mimic or inhibitor, cell proliferation, colony formation, migration, apoptosis, and cell cycle were evaluated. The expression levels of related proteins in the PTEN/PI3K/AKT pathway were also analyzed by Western blotting. Finally, the effect of tRF-5026a on tumor growth was tested using subcutaneous tumor models in nude mice. Results tRF-5026a was downregulated in gastric cancer patient tissues and plasma samples. tRF-5026a levels were closely related to tumor size, had a certain diagnostic value, and could be used to predict overall survival. tRF-5026a was also downregulated in gastric cancer cell lines. tRF-5026a inhibited the proliferation, migration, and cell cycle progression of gastric cancer cells by regulating the PTEN/PI3K/AKT signaling pathway. Animal experiments showed that upregulation of tRF-5026a effectively inhibited tumor growth. Conclusions tRF-5026a (tRF-18-79MP9P04) is a promising biomarker for gastric cancer diagnostics and has tumor suppressor effects mediated through the PTEN/PI3K/AKT signaling pathway.

Download Full-text

Downregulation of Sulfiredoxin (Srx) Suppressed Cell Proliferation Migration and Invasion Through Inhibiting Extracellular Signal-Regulated Kinase/Nrf2 Pathway in Hepatocellular Carcinoma

Journal of Biomaterials and Tissue Engineering ◽

10.1166/jbt.2021.2784 ◽

2021 ◽

Vol 11 (11) ◽

pp. 2137-2145

Author(s):

Xuejuan Zhu ◽

Danqian Lu

Keyword(s):

Cell Proliferation ◽

Western Blot ◽

Signaling Pathway ◽

Cell Lines ◽

Colony Formation ◽

Migration And Invasion ◽

Related Factor ◽

Extracellular Signal Regulated Kinase ◽

Extracellular Signal ◽

Nrf2 Signaling Pathway

Background: Sulfiredoxin (Srx) has been identified to play important roles in the development of various cancers. However, the precise effects and underlying mechanism of Srx on the progression of HCC are far from being fully understood. Materials and Methods: The abundances of Srx in THLE-2 cell and HCC cell lines were determined by western blot and RT-qPCR. Next, SK-Hep-1 cells were transfected with shRNA-Srx or shRNA-NC and treated with TBHQ (an extracellular signal-regulated kinase (ERK) activator) for functional experiments. Then, CCK8 and colony formation assays were used to determine cell proliferation and clone-forming abilities in vitro. Cell migration and invasion were assessed via wound healing and transwell assays. The expression of MMP2, MMP9 and key members in ERK/nuclear factor E2 related factor (Nrf2) signaling pathway was detected by performing western blot analysis. Results: We reported evidence that Srx was frequently up-regulated in HCC cell lines. Srx interference constrained cell proliferation, colony formation rate, migration and invasion of SK-Hep-1 cells. Moreover, mechanistic investigations indicated that Srx interference significantly inhibited the activation of ERK/Nrf2 signaling pathway, and ERK activator TBHQ can reverse the functions of Srx interference in SK-Hep-1 cells. Conclusion: Overall, Downregulation of Srx might impede HCC progression by suppressing ERK/Nrf2 signaling pathway. Findings in the current study reported the functional involvement and molecular mechanism of Srx in HCC, suggesting that Srx might have a potential therapeutic value in HCC treatment.

Download Full-text

Role of the G-Protein-Coupled Receptor Signaling Pathway in Insecticide Resistance

International Journal of Molecular Sciences ◽

10.3390/ijms20174300 ◽

2019 ◽

Vol 20 (17) ◽

pp. 4300 ◽

Cited By ~ 2

Author(s):

Ting Li ◽

Nannan Liu

Keyword(s):

Insecticide Resistance ◽

Cell Line ◽

Signaling Pathway ◽

G Protein ◽

Cell Lines ◽

Sf9 Cells ◽

Camp Production ◽

G Protein Coupled Receptor ◽

G Protein Coupled

The G-protein-coupled receptor (GPCR) regulated intracellular signaling pathway is known to be involved in the development of insecticide resistance in the mosquito, Culex quinquefasciatus. To elucidate the specific role of each effector in the GPCR regulating pathway, we initially expressed a GPCR, G-protein alpha subunit (Gαs), adenylate cyclase (AC), and protein kinase A (PKA) in insect Spodoptera frugiperda (Sf9) cells and investigated their regulation function on cyclic AMP (cAMP) production and PKA activity. GPCR, Gαs, and AC individually expressed Sf9 cells showed higher cAMP production as the expression of each effector increased. All the effector-expressed cell lines showed increased PKA activity however. Moreover, Sf9 cytochrome P450 gene expression and cell tolerance to permethrin were examined. The relative expression of CYP9A32gene in Sf9 cells tested was significantly increased in all effector-expressed cell lines compared to a control cell line; these effector-expressed cell lines also showed significantly higher tolerance to permethrin. Inhibitor treatments on each effector-expressed cell line revealed that Bupivacaine HCl and H89 2HCl robustly inhibited cAMP production and PKA activity, respectively, resulting in decreased tolerance to permethrin in all cell lines. The synergistic functions of Bupivacaine HCl and H89 2HCl with permethrin were further examined in Culex mosquito larvae, providing a valuable new information for mosquito control strategies.

Download Full-text

AKNA Is a Potential Prognostic Biomarker in Gastric Cancer and Function as a Tumor Suppressor by Modulating EMT-Related Pathways

BioMed Research International ◽

10.1155/2020/6726759 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10

Author(s):

Gang Wang ◽

Dan Sun ◽

Wenhui Li ◽

Yan Xin

Keyword(s):

Gastric Cancer ◽

Cell Adhesion ◽

Tumor Suppressor ◽

Western Blot ◽

Signaling Pathway ◽

Gene Set Enrichment Analysis ◽

Mesenchymal Transition ◽

Qrt Pcr ◽

Potential Biomarker ◽

Cell To Cell Adhesion

The AT-hook transcription factor, AKNA, is a nuclear protein that affects a few physiological and pathological processes including cancer. Here, we investigated the role of AKNA in gastric cancer (GC). By using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot assays, AKNA was found deregulated in both GC cell lines and 32 paired GC tissues. Subsequently, Kaplan-Meier analysis and clinicopathological analysis were conducted using both 32 GC cases’ data above and RNA-Seq data of AKNA in 354 GC patients and the corresponding clinical-pathological data obtained from The Cancer Genome Atlas (TCGA), and AKNA expression was found closely related to location, metastasis, and TNM staging of GC. Then, the potential molecular mechanisms of AKNA in GC were explored by gene set enrichment analysis (GSEA), qRT-PCR, and Western blot assays. AKNA was found to be a hub gene related to homotypic cell to cell adhesion, regulation of cell to cell adhesion, leukocyte cell to cell adhesion, and regulation of T cell proliferation in GC. GO analysis revealed that AKNA involved in the regulation of epithelial-mesenchymal transition (EMT)-related pathways including chemokine signaling pathway, cytokine to cytokine receptor interaction, cell adhesion molecules, and jak-stat signaling pathway in GC. To explore the regulation of AKNA expression, Targetscan and TargetMiner were used to predict the possible miRNA which targeted AKNA and found the expression of AKNA was negatively correlated to miR-762 which could be sponged by circTRNC18. In conclusion, AKNA could function as a tumor suppressor by modulating EMT-related pathways in GC. The expression of AKNA might be regulated by circTRNC18/miR-762 axis. AKNA could serve as a potential biomarker and an effective target for GC diagnosis and therapy.

Download Full-text

Long noncoding RNA 00976 promotes pancreatic cancer progression through OTUD7B by sponging miR-137 involving EGFR/MAPK pathway

Journal of Experimental & Clinical Cancer Research ◽

10.1186/s13046-019-1388-4 ◽

2019 ◽

Vol 38 (1) ◽

Cited By ~ 10

Author(s):

Shan Lei ◽

Zhiwei He ◽

Tengxiang Chen ◽

Xingjun Guo ◽

Zhirui Zeng ◽

...

Keyword(s):

Pancreatic Cancer ◽

Cell Proliferation ◽

Signaling Pathway ◽

Mapk Pathway ◽

Mapk Signaling ◽

Mapk Signaling Pathway ◽

Migration And Invasion ◽

Potential Biomarker

Abstract Background Accumulation evidence indicates the vital role of long non-coding RNAs (lncRNAs) in tumorigenesis and the progression of malignant tumors, including pancreatic cancer (PC). However, the role and the molecular mechanism of long non-coding RNA 00976 is unclear in pancreatic cancer. Methods In situ hybridization (ISH) and qRT-PCR was performed to investigate the association between linc00976 expression and the clinicopathological characteristics and prognosis of patients with PC. Subsequently, linc00976 over-expression vector and shRNAs were transfected into PC cells to up-regulate or down-regulate linc00976 expression. Loss- and gain-of function assays were performed to investigate the role of linc00976 in proliferation and metastasis in vitro and vivo. ITRAQ, bioinformatic analysis and rescue assay were used to illustrate the ceRNA mechanism network of linc00976/miR-137/OTUD7B and its downstream EGFR/MAPK signaling pathway. Results linc00976 expression was overexpressed in PC tissues and cell lines and was positively associated with poorer survival in patients with PC. Function studies revealed that linc00976 knockdown significantly suppressed cell proliferation, migration and invasion in vivo and in vitro, whereas its overexpression reversed these effects. Based on Itraq results and online database prediction, Ovarian tumor proteases OTUD7B was found as a downstream gene of linc00976, which deubiquitinated EGFR mediates MAPK signaling activation. Furthermore, Bioinformatics analysis and luciferase assays and rescue experiments revealed that linc00976/miR137/OTUD7B established the ceRNA network modulating PC cell proliferation and tumor growth. Conclusion The present study demonstrates that linc00976 enhances the proliferation and invasion ability of PC cells by upregulating OTUD7B expression, which was a target of miR-137. Ultimately, OTUD7B mediates EGFR and MAPK signaling pathway, suggesting that linc00976/miR-137/OTUD7B/EGFR axis may act as a potential biomarker and therapeutic target for PC.

Download Full-text

AML Survival and In Vivo Progression Is Dependent On β-Catenin Signaling.

Blood ◽

10.1182/blood.v114.22.2398.2398 ◽

2009 ◽

Vol 114 (22) ◽

pp. 2398-2398

Author(s):

Elena K Siapati ◽

Magda Papadaki ◽

Zoi Kozaou ◽

Erasmia Rouka ◽

Evridiki Michali ◽

...

Keyword(s):

Bone Marrow ◽

Wnt Signaling ◽

Signaling Pathway ◽

Cell Lines ◽

Wnt Signaling Pathway ◽

Canonical Wnt Signaling ◽

Down Regulation ◽

Canonical Wnt

Abstract Abstract 2398 Poster Board II-375 B-catenin is the central effector molecule of the canonical wnt signaling pathway which governs cell fate and differentiation during embryogenesis as well as self-renewal of hematopoietic stem cells. Deregulation of the pathway has been observed in various malignancies including myeloid leukemias where over-expression of β-catenin is an independent adverse prognostic factor. In the present study we examined the functional outcome of stable β-catenin down-regulation through lentivirus-mediated expression of short hairpin RNA (shRNA). Reduction of the β-catenin levels in AML cell lines and patient samples diminished their in vitro proliferation ability without significantly affecting cell viability. In order to study the role of β-catenin in vivo, we transplanted leukemic cell lines with control or reduced levels of β-catenin in NOD/SCID animals and analyzed the engraftment levels in the bone marrow. We observed that while the immediate homing of the cells was not affected by the β-catenin levels, the bone marrow engraftment was directly dependent on its levels. Subsequent examination of bone marrow sections revealed that the reduced engraftment was partly due to the inability of the cells with lower β-catenin levels to dock to the endosteal niches, a finding that was confirmed in competitive repopulation assays with untransduced cells. When we examined the expression levels of adhesion molecules and integrins in engrafted cells in vivo, we observed a significant down-regulation of CD44 expression, a molecule that participates in the interaction of HSCs with the niche. Gene expression analysis of the components of the wnt signaling pathway showed that the pathway is subject to tight transcriptional regulation with minor expression deviations. We did, however, observe an up-regulation in components that participate in the non-canonical wnt signaling pathways such as the WNT5B ligand. Ongoing experiments in normal cord blood CD34+ cells will determine the in vivo role of β-catenin signaling in normal hematopoietic progenitors. In conclusion, our study showed that β-catenin comprises an integral part in the development and progression of AML in vivo, indicating that manipulation of the wnt pathway may hold a therapeutic potential in the management of AML. Disclosures: No relevant conflicts of interest to declare.

Download Full-text

Re-Expression of the AML1/ETO Target Gene LAT2/NTAL/LAB Results In Direct Interference with Myeloid Differentiation In AML1/ETO-Positive Cells

Blood ◽

10.1182/blood.v116.21.2474.2474 ◽

2010 ◽

Vol 116 (21) ◽

pp. 2474-2474

Author(s):

Jesus Duque-Afonso ◽

Aitomi Essig ◽

Leticia M Solari ◽

Tobias Berg ◽

Heike L. Pahl ◽

...

Keyword(s):

Western Blot ◽

Cell Lines ◽

Functional Role ◽

Target Gene ◽

Conflicts Of Interest ◽

Myeloid Cell ◽

Leukemia Cells ◽

Myeloid Differentiation ◽

Granulocytic Differentiation

Abstract Abstract 2474 Background: The leukemia-specific oncofusion protein AML1/ETO regulates different target genes, including the LAT2 gene (encoding the adaptor molecule LAT2/NTAL/LAB), which is epigenetically repressed by AML1/ETO as we have previously described. LAT2 is phosphorylated by c-kit and has a role in mast cell and B cell activation. To address the functional role of LAT2 during myeloid differentiation, expression studies were performed in myeloid cell lines, and LAT2 was overexpressed by retroviral gene transfer in AML1/ETO-positive Kasumi-1 cells and AML1/ETO-negative U-937 cells. Methods: To induce monocytic and granulocytic differentiation, the myeloid cell lines U-937, HL-60 and NB4 were treated with PMA and ATRA, respectively, and LAT2 expression measured by both Northern and Western blot. LAT2 was overexpressed in Kasumi-1 and U-937 cells by use of the retroviral vector pMYSiG-IRES-GFP. Virus was produced in 293T cells and titrated in TE671 cells. Following transduction, GFP-positive cells were sorted by fluorescence-activated cell sorting (FACS). Transduced cells were treated with PMA (2 and 10 nM for 24 and 48 hours) and ATRA (0.1 μM and 0.5 μM for 48 and 96 hours), respectively. Results: The AML1/ETO-negative myeloid cell lines HL-60, NB4 and U-937 readily expressed LAT2, which was further upregulated by PMA, and transiently downregulated with ATRA. In the AML1/ETO-positive Kasumi-1 and SKNO-1 cells, LAT2 expression was absent. To address the functional role of this repression, forced expression of LAT2 was achieved in Kasumi-1 and U-937 cells and resulted in effective processing of LAT2 protein (confirmed by Western blot), and a decrease in the expression of the differentiation markers CD11b and CD11c (FACS analysis) in Kasumi-1 but not U-937, with only minor effects of LAT2 overexpression upon apoptosis and cell growth arrest. Notably, during both PMA- and ATRA-induced differentiation, a striking maturation block occurred in Kasumi-1 (measured by CD11b/CD11c expression, observed at different doses and time points of these treatments), while differentiation of U-937 cells was unimpaired by overexpression of LAT2. Conclusions: In AML1/ETO-negative leukemia cells, LAT2 expression is differentially regulated during monocytic and granulocytic differentiation. In AML1/ETO-positive leukemia cells, in which LAT2 is repressed, LAT2 re-expression imposes a striking maturation block. Graded expression of this novel AML1/ETO target gene may therefore play an important role in maintaining the phenotypic characteristics of this leukemia subtype. Disclosures: No relevant conflicts of interest to declare.

Download Full-text

Combined Carfilzomib and Selective PI3Kδ Inhibition (TGR1202) Results In Enhanced Myeloma Cell Apoptosis

Blood ◽

10.1182/blood.v122.21.3224.3224 ◽

2013 ◽

Vol 122 (21) ◽

pp. 3224-3224

Author(s):

Claire Torre ◽

Yanyan Gu ◽

Lawrence H. Boise ◽

Sagar Lonial

Keyword(s):

Multiple Myeloma ◽

Western Blot ◽

Signaling Pathway ◽

Cell Lines ◽

Proteasome Inhibitor ◽

Feedback Loop ◽

Myeloma Cell ◽

Pi3k Signaling ◽

Mtor Signaling Pathway ◽

The Impact

Abstract Introduction The PI3K signaling pathway plays a vital role in regulating cell growth, proliferation and survival in multiple myeloma (MM) as well as in many other cancers. TGR-1202, an isoform-specific PI3Kδ inhibitor, with efficacy in preclinical models of hematologic malignancies, is currently in Phase I clinical development. In multiple myeloma, PI3K signaling appears to be very important for many extracellular signals, yet inhibition with -pan PI3K inhibitors have not exhibited significant activity. However, literature reports indicate that there are several MM cell lines that express PI3K -δ, and do appear to have differential sensitivity to specific isoform inhibition as opposed to pan PI3K inhibition. In this report, we sought to evaluate the effects of TGR-1202 alone and in combination with the proteasome inhibitor carfilzomib, with the intent of further understanding the mechanism of action and evaluating the impact of the combination. Methods Human myeloma cell lines (MM.1S, MY5, RPMI8226, U266, KMS11, ARH-77, OPM1, OPM2, LP1, JJN3 and L363) were treated with TGR-1202 alone, carfilzomib alone, or with the combination of TGR-1202 and carfilzomib. Annexin V/PI staining and Western blot were used to identify the cellular and molecular sequelae of the combination. Result 10 µM TGR-1202 alone did not cause significant cell death in the MM cell lines tested at 48 hours. When cells were treated with the combination of TGR-1202 and 3 nM carfilzomib, we observed enhanced apoptosis in all of the tested cell lines. In the U266 cell line, 3 nM carfilzomib and 10 µM TGR-1202 induced 16% and 14% cell apoptosis respectively. In the combination treatment, apoptosis increased to 75%. To explore the molecular mechanisms underlying the combination, we used a Western blot assay to evaluate the impact of the combination on the mTOR signaling pathway, a known reciprocal feedback loop when PI3K is blocked. TGR-1202 alone did not have an obvious effect on the mTOR signaling pathway, yet combining TGR-1202 with carfilzomib, significantly inhibited phospho-mTOR, suggesting total pathway blockade. Conclusion The combination of TGR-1202 with carfilzomib induces synergistic apoptosis in MM cell lines. Preliminary data suggests that this occurs through blockade of the entire reciprocal feedback loop of mTOR activation. Additional data from primary patient samples and underlying mechanisms will be presented at the meeting. These findings support the rationale for future clinical studies of TGR-1202, a selective PI3K-δ inhibitor in combination with the proteasome inhibitor carfilzomib. Disclosures: Boise: Onyx: Consultancy. Lonial:Millennium: Consultancy; Celgene: Consultancy; Novartis: Consultancy; BMS: Consultancy; Sanofi: Consultancy; Onyx: Consultancy.

Download Full-text