Cholesterol Sensor SCAP Contributes to Sorafenib Resistance by Regulating Autophagy in Hepatocellular Carcinoma

2021 ◽  
Author(s):  
Danyang Li ◽  
Yingcheng Yao ◽  
Yuhan Rao ◽  
Xinyu Huang ◽  
Li Wei ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Lines ◽  
Malignant Tumors ◽  
Acquired Resistance ◽  
Clinical Samples ◽  
Significant Finding ◽  
Sorafenib Treatment ◽  
Associated Risk Factors

Abstract Background: Hepatocellular carcinoma (HCC) is one of the most malignant tumors and the fourth leading cause of cancer-related death worldwide. Sorafenib is currently acknowledged as a standard therapy for advanced HCC. However, acquired resistance substantially limits the clinical efficacy of sorafenib. Therefore, further investigations of the associated risk factors are highly warranted.Methods: We analysed a group of 78 HCC patients who received sorafenib treatment after liver resection surgery. The expression of SCAP and its correlation with sorafenib resistance in HCC clinical samples were determined by immunohistochemical analyses. Overexpression and knockdown approaches in vitro were used to characterize the functional roles of SCAP in regulating sorafenib resistance. The effects of SCAP inhibition in HCC cell lines were analysed in proliferation, apoptosis, and colony formation assays. Autophagic regulation by SCAP was assessed by immunoblotting, immunofluorescence and immunoprecipitation assays. The combinatorial effect of a SCAP inhibitor and sorafenib was tested using nude mice.Results: Hypercholesterolemia was associated with sorafenib resistance in HCC treatment. The degree of sorafenib resistance was correlated with the expression of the cholesterol sensor SCAP and consequent deposition of cholesterol. SCAP is overexpressed in HCC tissues and hepatocellular carcinoma cell lines with sorafenib resistance, while SCAP inhibition could improve sorafenib sensitivity in sorafenib-resistant HCC cells. Furthermore, we found that SCAP-mediated sorafenib resistance was related to decreased autophagy, which was connected to decreased AMPK activity. A clinically significant finding was that lycorine, a specific SCAP inhibitor, could reverse acquired resistance to sorafenib in vitro and in vivo.Conclusions: SCAP contributes to sorafenib resistance through AMPK-mediated autophagic regulation. The combination of sorafenib and SCAP targeted therapy provides a novel personalized treatment to enhance sensitivity in sorafenib-resistant HCC.

CDK12 inhibition mediates DNA damage and is synergistic with sorafenib treatment in hepatocellular carcinoma

Gut ◽  
2019 ◽  
Vol 69 (4) ◽  
pp. 727-736 ◽  
Author(s):  
Cun Wang ◽  
Hui Wang ◽  
Cor Lieftink ◽  
Aimee du Chatinier ◽  
Dongmei Gao ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Dna Damage ◽  
Cell Lines ◽  
Synergistic Effects ◽  
Loss Of Function ◽  
Bioinformatics Analyses ◽  
Sorafenib Treatment ◽  
Hcc Cells

ObjectivesHepatocellular carcinoma (HCC) is one of the most frequent malignancies and a major leading cause of cancer-related deaths worldwide. Several therapeutic options like sorafenib and regorafenib provide only modest survival benefit to patients with HCC. This study aims to identify novel druggable candidate genes for patients with HCC.DesignA non-biased CRISPR (clustered regularly interspaced short palindromic repeats) loss-of-function genetic screen targeting all known human kinases was performed to identify vulnerabilities of HCC cells. Whole-transcriptome sequencing (RNA-Seq) and bioinformatics analyses were performed to explore the mechanisms of the action of a cyclin-dependent kinase 12 (CDK12) inhibitor in HCC cells. Multiple in vitro and in vivo assays were used to study the synergistic effects of the combination of CDK12 inhibition and sorafenib.ResultsWe identify CDK12 as critically required for most HCC cell lines. Suppression of CDK12 using short hairpin RNAs (shRNAs) or its inhibition by the covalent small molecule inhibitor THZ531 leads to robust proliferation inhibition. THZ531 preferentially suppresses the expression of DNA repair-related genes and induces strong DNA damage response in HCC cell lines. The combination of THZ531 and sorafenib shows striking synergy by inducing apoptosis or senescence in HCC cells. The synergy between THZ531 and sorafenib may derive from the notion that THZ531 impairs the adaptive responses of HCC cells induced by sorafenib treatment.ConclusionOur data highlight the potential of CDK12 as a drug target for patients with HCC. The striking synergy of THZ531 and sorafenib suggests a potential combination therapy for this difficult to treat cancer.

scholarly journals BEZ235 Increases the Sensitivity of Hepatocellular Carcinoma to Sorafenib by Inhibiting PI3K/AKT/mTOR and Inducing Autophagy

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Weiya Cao ◽  
Xueke Liu ◽  
Yinci Zhang ◽  
Amin Li ◽  
Yinghai Xie ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Cycle ◽  
Cell Lines ◽  
Acquired Resistance ◽  
Inhibitory Effect ◽  
Mtor Pathway ◽  
Protein Levels ◽  
Huh7 Cells

Acquired resistance of hepatocellular carcinoma (HCC) to sorafenib (SFB) is the main reason for the failure of SFB treatment of the cancer. Abnormal activation of the PI3K/AKT/mTOR pathway is important in the acquired resistance of SFB. Therefore, we investigated whether BEZ235 (BEZ) could reverse acquired sorafenib resistance by targeting the PI3K/mTOR pathway. A sorafenib-resistant HCC cell line Huh7R was established. MTT assay, clone formation assay, flow cytometry, and immunofluorescence were used to analyze the effects of BEZ235 alone or combined with sorafenib on cell proliferation, cell cycle, apoptosis, and autophagy of Huh7 and Huh7R cells. The antitumor effect was evaluated in animal models of Huh7R xenografts in vivo. Western blot was used to detect protein levels of the PI3K/AKT/mTOR pathway and related effector molecules. In vitro results showed that the Huh7R had a stronger proliferation ability and antiapoptosis effect than did Huh7, and sorafenib had no inhibitory effect on Huh7R. SFB + BEZ inhibited the activation of the PI3K/AKT/mTOR pathway caused by sorafenib. Moreover, SFB + BEZ inhibited the proliferation and cloning ability, blocked the cell cycle in the G0/G1 phase, and promoted apoptosis in the two cell lines. The autophagy level in Huh7R cells was higher than in Huh7 cells, and BEZ or SFB + BEZ further promoted autophagy in the two cell lines. In vivo, SFB + BEZ inhibited tumor growth by inducing apoptosis and autophagy. We concluded that BEZ235 enhanced the sensitivity of sorafenib through suppressing the PI3K/AKT/mTOR pathway and inducing autophagy. These observations may provide the experimental basis for sorafenib combined with BEZ235 in trial treatment of HCC.

scholarly journals N6-methyladenosine-modified CircRNA-SORE sustains sorafenib resistance in hepatocellular carcinoma by regulating β-catenin signaling

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Junjie Xu ◽  
Zhe Wan ◽  
Minyue Tang ◽  
Zhongjie Lin ◽  
Shi Jiang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Clinical Investigation ◽  
Acquired Resistance ◽  
Rna Stability ◽  
Circular Rna ◽  
Clinical Samples ◽  
In Vivo Experiments ◽  
Induced Apoptosis

Abstract Background and aims Accumulating evidence suggests that the primary and acquired resistance of hepatocellular carcinoma (HCC) to sorafenib is mediated by multiple molecular, cellular, and microenvironmental mechanisms. Understanding these mechanisms will enhance the likelihood of effective sorafenib therapy. Methods In vitro and in vivo experiments were performed and clinical samples and online databases were acquired for clinical investigation. Results In this study, we found that a circular RNA, circRNA-SORE, which is up-regulated in sorafenib-resistant HCC cells, was necessary for the maintenance of sorafenib resistance, and that silencing circRNA-SORE substantially increased the efficacy of sorafenib-induced apoptosis. Mechanistic studies determined that circRNA-SORE sequestered miR-103a-2-5p and miR-660-3p by acting as a microRNA sponge, thereby competitively activating the Wnt/β-catenin pathway and inducing sorafenib resistance. The increased level of circRNA-SORE in sorafenib-resistant cells resulted from increased RNA stability. This was caused by an increased level of N6-methyladenosine (m6A) at a specific adenosine in circRNA-SORE. In vivo delivery of circRNA-SORE interfering RNA by local short hairpin RNA lentivirus injection substantially enhanced sorafenib efficacy in animal models. Conclusions This work indicates a novel mechanism for maintaining sorafenib resistance and is a proof-of-concept study for targeting circRNA-SORE in sorafenib-treated HCC patients as a novel pharmaceutical intervention for advanced HCC.

scholarly journals Verteporfin-induced lysosomal compartment dysregulation potentiates the effect of sorafenib in hepatocellular carcinoma

2019 ◽  
Vol 10 (10) ◽  
Author(s):  
Jacopo Gavini ◽  
Noëlle Dommann ◽  
Manuel O. Jakob ◽  
Adrian Keogh ◽  
Laure C. Bouchez ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Lines ◽  
Antitumor Effect ◽  
Acquired Resistance ◽  
Xenograft Model ◽  
Resistance Mechanisms ◽  
Chemotherapeutic Agents ◽  
Anti Cancer

Abstract Lysosomal sequestration of anti-cancer compounds reduces drug availability at intracellular target sites, thereby limiting drug-sensitivity and inducing chemoresistance. For hepatocellular carcinoma (HCC), sorafenib (SF) is the first line systemic treatment, as well as a simultaneous activator of autophagy-induced drug resistance. The purpose of this study is to elucidate how combination therapy with the FDA-approved photosensitizer verteporfin (VP) can potentiate the antitumor effect of SF, overcoming its acquired resistance mechanisms. HCC cell lines and patient-derived in vitro and in vivo preclinical models were used to identify the molecular mechanism of action of VP alone and in combination with SF. We demonstrate that SF is lysosomotropic and increases the total number of lysosomes in HCC cells and patient-derived xenograft model. Contrary to the effect on lysosomal stability by SF, VP is not only sequestered in lysosomes, but induces lysosomal pH alkalinization, lysosomal membrane permeabilization (LMP) and tumor-selective proteotoxicity. In combination, VP-induced LMP potentiates the antitumor effect of SF, further decreasing tumor proliferation and progression in HCC cell lines and patient-derived samples in vitro and in vivo. Our data suggest that combination of lysosome-targeting compounds, such as VP, in combination with already approved chemotherapeutic agents could open a new avenue to overcome chemo-insensitivity caused by passive lysosomal sequestration of anti-cancer drugs in the context of HCC.

Long noncoding RNA Linc01296 promotes hepatocellular carcinoma development through regulation of the miR-26a/PTEN axis

2020 ◽  
Vol 401 (3) ◽  
pp. 407-416 ◽  
Author(s):  
Libin Zhang ◽  
Jing Hu ◽  
Menghui Hao ◽  
Liang Bu
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Lines ◽  
Long Noncoding Rna ◽  
Noncoding Rna ◽  
Malignant Tumors ◽  
Cell Counting ◽  
Tumor Xenograft ◽  
Migration And Invasion

AbstractLong noncoding RNA 01296 (Lnc01296) is dysregulated in malignant tumors. However, the detailed effect of Linc01296 on hepatocellular carcinoma (HCC) remains largely unknown. In this study, we identified the biological role of Linc01296 in HCC. The levels of Linc01296 in HCC tissues and a panel of cell lines were assessed by quantitative real-time polymerase chain reaction (qRT-PCR). The effects of Linc01296 on HCC progression were explored using a Cell Counting Kit-8 (CCK-8), flow cytometry, migration and Transwell invasion assays. The interactions among Linc01296, miR-26a and PTEN were determined using luciferase, RNA immunoprecipitation (RIP) and Western blot assays. Tumor xenograft models were utilized to confirm the in vivo functional roles of Linc01296 in HCC development. Linc01296 expression was increased in both HCC tissue samples and cell lines. Knockdown of Linc01296 suppressed HCC cell processes, such as proliferation, migration and invasion, and enhanced apoptosis in vitro; these effects were reversed by a miR-26a mimic or PTEN overexpression. Furthermore, knockdown of Linc01296 suppressed HCC growth in vivo. These findings indicated that Linc01296 is involved in HCC progression via regulating miR-26a/PTEN.

scholarly journals Radiosensitisation of Hepatocellular Carcinoma Cells by Vandetanib

Cancers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1878 ◽  
Author(s):  
Sami Znati ◽  
Rebecca Carter ◽  
Marcos Vasquez ◽  
Adam Westhorpe ◽  
Hassan Shahbakhti ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Combination Therapy ◽  
Cell Lines ◽  
Radiation Treatment ◽  
Combined Treatment ◽  
New Combination ◽  
Migration And Invasion ◽  
Syngeneic Mouse Model

Hepatocellular Carcinoma (HCC) is increasing in incidence worldwide and requires new approaches to therapy. The combination of anti-angiogenic drug therapy and radiotherapy is one promising new approach. The anti-angiogenic drug vandetanib is a tyrosine kinase inhibitor of vascular endothelial growth factor receptor-2 (VEGFR-2) and RET proto-oncogene with radio-enhancement potential. To explore the benefit of combined vandetanib and radiotherapy treatment for HCC, we studied outcomes following combined treatment in pre-clinical models. Methods: Vandetanib and radiation treatment were combined in HCC cell lines grown in vitro and in vivo. In addition to 2D migration and clonogenic assays, the combination was studied in 3D spheroids and a syngeneic mouse model of HCC. Results: Vandetanib IC 50 s were measured in 20 cell lines and the drug was found to significantly enhance radiation cell kill and to inhibit both cell migration and invasion in vitro. In vivo, combination therapy significantly reduced cancer growth and improved overall survival, an effect that persisted for the duration of vandetanib treatment. Conclusion: In 2D and 3D studies in vitro and in a syngeneic model in vivo, the combination of vandetanib plus radiotherapy was more efficacious than either treatment alone. This new combination therapy for HCC merits evaluation in clinical trials.

scholarly journals Downregulation of CRABP2 Inhibit the Tumorigenesis of Hepatocellular Carcinoma In Vivo and In Vitro

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Qingmin Chen ◽  
Ludong Tan ◽  
Zhe Jin ◽  
Yahui Liu ◽  
Ze Zhang
Keyword(s):  
Hepatocellular Carcinoma ◽  
Retinoic Acid ◽  
Cell Lines ◽  
Molecular Mechanisms ◽  
Tumor Stage ◽  
Migration And Invasion ◽  
Hcc Cells

Cellular retinoic acid-binding protein 2 (CRABP2) binds retinoic acid (RA) in the cytoplasm and transports it into the nucleus, allowing for the regulation of specific downstream signal pathway. Abnormal expression of CRABP2 has been detected in the development of several tumors. However, the role of CRABP2 in hepatocellular carcinoma (HCC) has never been revealed. The current study aimed to investigate the role of CRABP2 in HCC and illuminate the potential molecular mechanisms. The expression of CRABP2 in HCC tissues and cell lines was detected by western blotting and immunohistochemistry assays. Our results demonstrated that the expression levels of CRABP2 in HCC tissues were elevated with the tumor stage development, and it was also elevated in HCC cell lines. To evaluate the function of CRABP2, shRNA-knockdown strategy was used in HCC cells. Cell proliferation, metastasis, and apoptosis were analyzed by CCK-8, EdU staining, transwell, and flow cytometry assays, respectively. Based on our results, knockdown of CRABP2 by shRNA resulted in the inhibition of tumor proliferation, migration, and invasion in vitro, followed by increased tumor apoptosis-related protein expression and decreased ERK/VEGF pathway-related proteins expression. CRABP2 silencing in HCC cells also resulted in the failure to develop tumors in vivo. These results provide important insights into the role of CRABP2 in the development and development of HCC. Based on our findings, CRABP2 may be used as a novel diagnostic biomarker, and regulation of CRABP2 in HCC may provide a potential molecular target for the therapy of HCC.

The BH3 Mimetic, ABT-737, Is Effective Against Bcl-2 Overexpressing Lymphoid Tumors.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 826-826 ◽  
Author(s):  
Kylie D. Mason ◽  
Cassandra J. Vandenberg ◽  
Mark F. van Delft ◽  
Andrew H. Wei ◽  
Suzanne Cory ◽  
...  
Keyword(s):  
Cell Lines ◽  
Genetic Manipulation ◽  
Single Agent ◽  
B Cell Lymphoma ◽  
Cell Types ◽  
Clinical Samples ◽  
Bh3 Mimetic ◽  
Mouse Lymphoma

Abstract Lymphoid tumors often respond poorly to conventional cytotoxics, a common cause being their impaired sensitivity to apoptosis, such as that caused by Bcl-2 overexpression. A strategy to overcoming this is to use mimics of the natural antagonists of pro-survival Bcl-2, the BH3 only proteins. A promising BH3 mimetic is ABT-737, which targets Bcl-2 and closely related pro-survival proteins. We evaluated its potential utility by testing it on cell lines, clinical samples and on a relevant mouse lymphoma model. We assessed the sensitivity of B cell lymphoma cell lines and primary CLL samples to ABT-737, either alone or in combination. To ascertain its efficacy in vivo, we utilized a mouse model based on the Eμ-myc tumor that is readily transplantable and amenable to genetic manipulation. When syngeneic recipient mice were inoculated with tumors, they develop widespread lymphoma, fatal unless treated by agents such as cyclophosphamide. We found that ABT-737, on its own, was cytotoxic only to a subset of cell lines and primary CLL samples. However, it can synergize potently with agents such as dexamethasone, suggesting that this agent might be useful in combination with currently used chemotherapeutics. In the Eμ myc mouse lymphoma model, treatment with ABT-737 alone did not control the disease as multiple independently derived tumors proved refractory to treatment with this agent. However, ABT-737 was partially effective as a single agent for treating bitransgenic tumors derived from crosses of the Eμmyc and Eμ-bcl-2 transgenic mice. ABT-737 therapy prolonged the survival of recipient mice transplanted with tumors from 30 to 60 days. When combined with a low dose of cyclophosphamide (50mg/kg), long term stable remissions were achieved, which were sustained even longer than control mice treated with much higher doses of cyclophosphamide (300mg/kg). We found that ABT-737 was well tolerated as a single agent and when combined with low doses of cytotoxics such as cyclophosphamide. Thus, ABT-737 may prove to be efficacious for those tumors highly dependent on Bcl-2 for their survival. We found that despite its high affinity for Bcl-2, Bcl-xL and Bcl-w, many cell types proved refractory to ABT-737 as a single agent. We show that this resistance reflects its inability to target another pro-survival relative Mcl-1. Down-regulation of Mcl-1 by several strategies conferred sensitivity to ABT-737. Furthermore, enforced Mcl-1 expression in the Eμmyc/bcl-2 bitransgenic mouse lymphoma model conferred marked resistance as mice transplanted with such tumors died as rapidly as the untreated counterparts. However, enhanced Bcl-2 overexpression on these tumors had little impact on the in vivo response, suggesting that ABT-737 can be utilized even when Bcl-2 is markedly overexpressed. ABT-737 appears to be a promising agent for the clinic. It potently sensitizes certain lymphoid tumors to conventional cytotxics in vitro. The synergy observed between dexamethasone and ABT-737 on some lymphoid lines in culture suggests that it is attractive for clinical testing. Encouragingly, ABT-737 appeared efficacious in vivo against Bcl-2 overexpressing tumors when combined with a reduced dose of cyclophosphamide, suggesting that it will be useful for treating even those Bcl-2-overexpressing tumors that are normally highly chemoresistant.

Preclinical Rationale for the Use of the Combined Treatment with the AKT Inhibitor Perifosine and the Multikinase Inhibitor Sorafenib in Hodgkin Lymphoma

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1653-1653
Author(s):  
Silvia Locatelli ◽  
Arianna Giacomini ◽  
Anna Guidetti ◽  
Loredana Cleris ◽  
Michele Magni ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Cell Line ◽  
Cell Lines ◽  
Drug Combination ◽  
Akt Inhibitor ◽  
Sorafenib Treatment ◽  
Responsive Cell

Abstract Abstract 1653 Introduction: A significant proportion of Hodgkin lymphoma (HL) patients refractory to first-line chemotherapy or relapsing after autologous transplantation are not cured with currently available treatments and require new treatments. The PI3K/AKT and RAF/MEK/ERK pathways are constitutively activated in the majority of HL. These pathways can be targeted using the AKT inhibitor perifosine (Æterna Zentaris GmBH, Germany, EU), and the RAF/MEK/ERK inhibitor sorafenib (Nexavar®, Bayer, Germany, EU). We hypothesized that perifosine in combination with sorafenib might have a therapeutic activity in HL by overcoming the cytoprotective and anti-apoptotic effects of PI3K/Akt and RAF/MEK/ERK pathways. Since preclinical evidence supporting the anti-lymphoma effects of the perifosine/sorafenib combination are still lacking, the present study aimed at investigating in vitro and in vivo the activity and mechanism(s) of action of this two-drug combination. METHODS: Three HL cell lines (HD-MyZ, L-540 and HDLM-2) were used to investigate the effects of perifosine and sorafenib using in vitro assays analyzing cell growth, cell cycle distribution, gene expression profiling (GEP), and apoptosis. Western blotting (WB) experiments were performed to determine whether the two-drug combination affected MAPK and PI3K/AKT pathways as well as apoptosis. Additionally, the antitumor efficacy and mechanism of action of perifosine/sorafenib combination were investigated in vivo in nonobese diabetic/severe combined immune-deficient (NOD/SCID) mice. RESULTS: While perifosine and sorafenib as single agents exerted a limited activity against HL cells, exposure of HD-MyZ and L-540 cell lines, but not HDLM-2 cells, to perifosine/sorafenib combination resulted in synergistic cell growth inhibition (40% to 80%) and cell cycle arrest. Upon perifosine/sorafenib exposure, L-540 cell line showed significant levels of apoptosis (up to 70%, P ≤.0001) associated with severe mitochondrial dysfunction (cytochrome c, apoptosis-inducing factor release and marked conformational change of Bax accompanied by membrane translocation). Apoptosis induced by perifosine/sorafenib combination did not result in processing of caspase-8, -9, -3, or cleavage of PARP, and was not reversed by the pan-caspase inhibitor Z-VADfmk, supporting a caspase-independent mechanism of apoptosis. In responsive cell lines, WB analysis showed that anti-proliferative events were associated with dephosphorylation of MAPK and PI3K/Akt pathways. GEP analysis of HD-MyZ and L-540 cell lines, but not HDLM-2 cells indicated that perifosine/sorafenib treatment induced upregulation of genes involved in amino acid metabolism and downregulation of genes regulating cell cycle, DNA replication and cell death. In addition, in responsive cell lines, perifosine/sorafenib combination strikingly induced the expression of tribbles homologues 3 (TRIB3) both in vitro and in vivo. Silencing of TRIB3 prevented cell growth reduction induced by perifosine/sorafenib treatment. In vivo, the combined perifosine/sorafenib treatment significantly increased the median survival of NOD/SCID mice xenografted with HD-MyZ cell line as compared to controls (81 vs 45 days, P ≤.0001) as well as mice receiving perifosine alone (49 days, P ≤.03) or sorafenib alone (54 days, P ≤.007). In mice bearing subcutaneous nodules generated by HD-MyZ and L-540 cell lines but not HDLM-2 cell line, perifosine/sorafenib treatment induced significantly increased levels of apoptosis (2- to 2.5-fold, P ≤.0001) and necrosis (2- to 8-fold, P ≤.0001), as compared to controls or treatment with single agents. CONCLUSIONS: Perifosine/sorafenib combination resulted in potent anti-HL activity both in vitro and in vivo. These results warrant clinical evaluation in HL patients. Disclosures: No relevant conflicts of interest to declare.

Synergistic growth inhibition of RCC and NSCLC cell lines by sorafenib plus vorinostat and induction of angiogenic genes by ER stress

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e16114-e16114
Author(s):  
H. A. Drabkin ◽  
G. Sharma ◽  
L. J. Costa ◽  
C. Korch ◽  
R. M. Gemmill
Keyword(s):  
Growth Inhibition ◽  
Er Stress ◽  
Cell Lines ◽  
Acquired Resistance ◽  
Resistance Mechanisms ◽  
Angiogenic Factors ◽  
Nsclc Cell ◽  
Angiogenic Genes

e16114 Sorafenib, vorinostat and the combination were examined in 34 RCC and NSCLC cell lines. In growth assays, sorafenib at 8 μM resulted in synergy with multiple vorinostat doses, whereas no synergy was seen with lower doses. Changes in phospho-ERK and AKT were not predictive of growth inhibition, whereas frequent inhibition of cyclin D1 and upregulation of p21Waf1 was observed. To anticipate resistance mechanisms to the anti-angiogenic effects of sorafenib, we studied the expression of 13 angiogenic factors in 10 selected lines. At baseline, bFGF, VEGF and IL-8 were highly expressed in RCCs, whereas Gro-α, VEGF, and IL-8 predominated in NSCLCs. Multiple angiogenic factors were upregulated by sorafenib and vorinostat, especially VEGF, IL-6, CTGF, EDN1, PDGFβ, and IL-8. Importantly, sorafenib at 8 μM, but not lower doses, induced ER stress in these cell lines and thapsigargin or tunicamycin treatment recapitulated many, but not all, of the observed angiogenic gene responses to sorafenib. In fact, CHOP induction by sorafenib plus vorinostat was the only parameter, other than growth inhibition, that changed in a synergistic manner. In summary, sorafenib plus vorinostat potently inhibits the in vitro growth of RCC and NSCLC cell lines. Upregulation of multiple angiogenic genes, in part by an ER-stress mechanism, may contribute to acquired resistance in vivo. No significant financial relationships to disclose.

Sign in / Sign up

Export Citation Format

Share Document