Research IndicatorsGraph generated 13 March 2017 using data from PubMed using criteria.
Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic. Tag cloud generated 13 March, 2017 using data from PubMed, MeSH and CancerIndex
Specific Cancers (4)
Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.
Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).
OMIM, Johns Hopkin University
Referenced article focusing on the relationship between phenotype and genotype.
International Cancer Genome Consortium.
Summary of gene and mutations by cancer type from ICGC
Cancer Genome Anatomy Project, NCI
COSMIC, Sanger Institute
Somatic mutation information and related details
GEO Profiles, NCBI
Search the gene expression profiles from curated DataSets in the Gene Expression Omnibus (GEO) repository.
Latest Publications: HDAC6 (cancer-related)
Simões-Pires CA, Bertrand P, Cuendet MNovel histone deacetylase 6 (HDAC6) selective inhibitors: a patent evaluation (WO2014181137).
Expert Opin Ther Pat. 2017; 27(3):229-236 [PubMed
] Related Publications
INTRODUCTION: Histone deacetylases (HDACs) are known to deacetylate histones and other proteins, which makes HDAC inhibitors able to affect cell survival, cell signaling, transport, and gene expression. Those effects have been associated to the therapeutic success of HDAC inhibitors. Class I-selective or pan-HDAC inhibitors have been approved for cancer therapy by the US Food and Drug Administration (FDA). Moreover, HDAC6 selective inhibitors entered phase I and II clinical trials for treating multiple myeloma. The development of potent and selective HDAC inhibitors is a hot topic in current drug discovery. Areas covered: The invention described in this patent (WO2014181137) is related to hydroxamic acid derivatives with inhibitory activity towards HDACs, their synthetic process and pharmaceutical formulations, as well as a method for treating patients suffering from a list of selected tumoral, inflammatory, cardiac and chronic disorders. Expert opinion: The compounds disclosed within this patent are selective against HDAC6 and their structure is related to tubastatin A, a known HDAC6 selective inhibitor. They are newly synthesized diarylamines showing an improved selectivity profile compared to other diarylamines under clinical investigation.
Shah AA, Ito A, Nakata A, Yoshida MIdentification of a Selective SIRT2 Inhibitor and Its Anti-breast Cancer Activity.
Biol Pharm Bull. 2016; 39(10):1739-1742 [PubMed
] Related Publications
SIRT2 is a member of the human sirtuin family of proteins and possesses nicotinamide adenine dinucleotide (NAD)-dependent lysine deacetylase activity. SIRT2 has been involved in various cellular processes including gene transcription, genome constancy, and the cell cycle. In addition, SIRT2 is deeply implicated in diverse diseases including cancer. In this study, we identified a small molecule inhibitor of SIRT2 with a structure different from known SIRT2 inhibitors by screening from a chemical library. The hit compound showed a high selectivity toward SIRT2 as it only inhibited SIRT2, and not other sirtuins including SIRT1 and SIRT3 or zinc-dependent histone deacetylases (HDACs) including HDAC1 and HDAC6, in vitro. The compound increased the acetylation level of eukaryotic translation initiation factor 5A (eIF5A), a physiological substrate of SIRT2, and reduced cell viability of human breast cancer cells accompanied with a decrease in c-Myc expression. These results suggest that the compound is cellular effective and has potential for development as a therapeutic agent against breast cancers by specific inhibition of SIRT2.
In addition to oncogenic drivers, signaling nodes can critically modulate cancer-related cellular networks to strength tumor hallmarks. We identify G-protein-coupled receptor kinase 2 (GRK2) as a relevant player in breast cancer. GRK2 is up-regulated in breast cancer cell lines, in spontaneous tumors in mice, and in a proportion of invasive ductal carcinoma patients. Increased GRK2 functionality promotes the phosphorylation and activation of the Histone Deacetylase 6 (HDAC6) leading to de-acetylation of the Prolyl Isomerase Pin1, a central modulator of tumor progression, thereby enhancing its stability and functional interaction with key mitotic regulators. Interestingly, a correlation between GRK2 expression and Pin1 levels and de-acetylation status is detected in breast cancer patients. Activation of the HDAC6-Pin1 axis underlies the positive effects of GRK2 on promoting growth factor signaling, cellular proliferation and anchorage-independent growth in both luminal and basal breast cancer cells. Enhanced GRK2 levels promote tumor growth in mice, whereas GRK2 down-modulation sensitizes cells to therapeutic drugs and abrogates tumor formation. Our data suggest that GRK2 acts as an important onco-modulator by strengthening the functionality of key players in breast tumorigenesis such as HDAC6 and Pin1.
Histone deacetylases (HDACs) critically regulate gene expression by determining the acetylation status of histones. Studies have increasingly focused on the activities of HDACs, especially involving non-histone proteins, and their various biological effects. Aberrant HDAC expression observed in several kinds of human tumors makes HDACs potential targets for cancer treatment. Several preclinical studies have suggested that HDAC inhibitors show some efficacy in the treatment of acute myelogenous leukemia with AML1-ETO, which mediates transcriptional repression through its interaction with a complex including HDAC1. Recurrent mutations in epigenetic regulators are found in T-cell lymphomas (TCLs), and HDAC inhibitors and hypomethylating agents were shown to act cooperatively in the treatment of TCLs. Preclinical modeling has suggested that persistent activation of the signal transducer and activator of transcription signaling pathway could serve as a useful biomarker of resistance to HDAC inhibitor in patients with cutaneous TCL. Panobinostat, a pan-HDAC inhibitor, in combination with bortezomib and dexamethasone, has achieved longer progression-free survival in patients with relapsed/refractory multiple myeloma (MM) than the placebo in combination with bortezomib and dexamethasone. Panobinostat inhibited MM cell growth by degrading protein phosphatase 3 catalytic subunit α (PPP3CA), a catalytic subunit of calcineurin. This degradation was suggested to be mediated by the blockade of the chaperone function of heat shock protein 90 due to HDAC6 inhibition. Aberrant PPP3CA expression in advanced MM indicated a possible correlation between high PPP3CA expression and the pathogenesis of MM. Furthermore, PPP3CA was suggested as a common target of panobinostat and bortezomib.
Histone deacetylase inhibitors (HDIs) represent a new class of anticancer drugs. Suberoylanilide hydroxamic acid (SAHA), the first HDI approved for the treatment of cutaneous T cell lymphoma (CTCL), is currently being tested in clinical trials for other cancers. However, SAHA has been ineffective against solid tumors in many clinical trials. A better understanding of molecular mechanisms of SAHA resistance may provide the basis for improved patient selection and the enhancement of clinical efficacy. Here we demonstrate that oncogenic K-ras contributes to SAHA resistance by upregulating HDAC6 and c-myc expression. We find that the high levels of HDAC6 expression are associated with activated K-ras mutant in colon cancer patients. And expressions of HDAC6 and c-myc are increased in fibroblasts transformed with activated K-ras. Surprisingly, we find that activated K-ras transformed cells are more resistant to SAHA inhibition on cell growth and anchorage-independent colony formation. We show that a K-ras inhibitor sensitizes K-ras mutated lung cancer cells to SAHA induced growth inhibition. We also find that mutant K-ras induces HDAC6 expression by a MAP kinase dependent pathway. Our study suggests that combined treatment with SAHA and K-ras inhibitors may represent an effective strategy to overcome SAHA resistance.
BACKGROUND: Histone deacetylase (HDAC) inhibitors are widely used in clinical investigation as novel drug targets. For example, panobinostat and vorinostat have been used to treat patients with melanoma. However, HDAC inhibitors are small-molecule compounds without a specific target, and their mechanism of action is unclear. Therefore, it is necessary to investigate which HDACs are required for the proliferation and metastasis of melanoma cells.
METHODS: We used overexpression and knocking down lentivirus to clarify the influence of HDAC5 and HDAC6 in melanoma development. Also, we introduced stable HDAC5 or HDAC6 knockdown cells into null mice and found that the knockdown cells were unable to form solid tumors. Finally, we tested HDAC5 and HDAC6 expression and sub-location in clinical melanoma tissues and tumor adjacent tissues.
RESULTS: In this study, and found that HDAC5 and HDAC6 were highly expressed in melanoma cells but exhibited low expression levels in normal skin cells. Furthermore, we knocked down HDAC5 or HDAC6 in A375 cells and demonstrated that both HDAC5 and HDAC6 contributed to the proliferation and metastasis of melanoma cells.
CONCLUSIONS: This study demonstrated both HDAC5 and HDAC6 were required for melanoma cell proliferation and metastasis through different signaling pathways.
Wang L, Kofler M, Brosch G, et al.2-Benzazolyl-4-Piperazin-1-Ylsulfonylbenzenecarbohydroxamic Acids as Novel Selective Histone Deacetylase-6 Inhibitors with Antiproliferative Activity.
PLoS One. 2015; 10(12):e0134556 [PubMed
] Free Access to Full Article Related Publications
We have screened our compound collection in an established cell based assay that measures the derepression of an epigenetically silenced transgene, the locus derepression assay. The screen led to the identification of 4-[4-(1-methylbenzimidazol-2-yl)piperazin-1-yl]sulfonylbenzenecarbohydroxamic acid (9b) as an active which was found to inhibit HDAC1. In initial structure activity relationships study, the 1-methylbenzimidazole ring was replaced by the isosteric heterocycles benzimidazole, benzoxazole, and benzothiazole and the position of the hydroxamic acid substituent on the phenyl ring was varied. Whereas compounds bearing a para substituted hydroxamic acid (9a-d) were active HDAC inhibitors, the meta substituted analogues (8a-d) were appreciably inactive. Compounds 9a-d selectively inhibited HDAC6 (IC50 = 0.1-1.0 μM) over HDAC1 (IC50 = 0.9-6 μM) and moreover, also selectively inhibited the growth of lung cancer cells vs. patient matched normal cells. The compounds induce a cell cycle arrest in the S-phase while induction of apoptosis is neglible as compared to controls. Molecular modeling studies uncovered that the MM-GBSA energy for interaction of 9a-d with HDAC6 was higher than for HDAC1 providing structural rationale for the HDAC6 selectivity.
INTRODUCTION: Inflammatory breast cancer (IBC) is the most lethal form of breast cancers with a 5-year survival rate of only 40 %. Despite its lethality, IBC remains poorly understood which has greatly limited its therapeutic management. We thus decided to utilize an integrative functional genomic strategy to identify the Achilles' heel of IBC cells.
METHODS: We have pioneered the development of genetic tools as well as experimental and analytical strategies to perform RNAi-based loss-of-function studies at a genome-wide level. Importantly, we and others have demonstrated that these functional screens are able to identify essential functions linked to certain cancer phenotypes. Thus, we decided to use this approach to identify IBC specific sensitivities.
RESULTS: We identified and validated HDAC6 as a functionally necessary gene to maintain IBC cell viability, while being non-essential for other breast cancer subtypes. Importantly, small molecule inhibitors for HDAC6 already exist and are in clinical trials for other tumor types. We thus demonstrated that Ricolinostat (ACY1215), a leading HDAC6 inhibitor, efficiently controls IBC cell proliferation both in vitro and in vivo. Critically, functional HDAC6 dependency is not associated with genomic alterations at its locus and thus represents a non-oncogene addiction. Despite HDAC6 not being overexpressed, we found that its activity is significantly higher in IBC compared to non-IBC cells, suggesting a possible rationale supporting the observed dependency.
CONCLUSION: Our finding that IBC cells are sensitive to HDAC6 inhibition provides a foundation to rapidly develop novel, efficient, and well-tolerated targeted therapy strategies for IBC patients.
Giaginis C, Damaskos C, Koutsounas I, et al.Histone deacetylase (HDAC)-1, -2, -4 and -6 expression in human pancreatic adenocarcinoma: associations with clinicopathological parameters, tumor proliferative capacity and patients' survival.
BMC Gastroenterol. 2015; 15:148 [PubMed
] Free Access to Full Article Related Publications
BACKGROUND: Histone deacetylases (HDACs) have been associated with malignant tumor development and progression in humans. HDAC inhibitors (HDACIs) are currently being explored as anti-cancer agents in clinical trials. The present study aimed to evaluate the clinical significance of HDAC-1, -2, -4 and -6 protein expression in pancreatic adenocarcinoma.
METHODS: HDAC-1, -2, -4 and -6 protein expression was assessed immunohistochemically on 70 pancreatic adenocarcinoma tissue specimens and was statistically analyzed with clinicopathological characteristics and patients' survival.
RESULTS: Enhanced HDAC-1 expression was significantly associated with increased tumor proliferative capacity (p = 0.0238) and borderline with the absence of lymph node metastases (p = 0.0632). Elevated HDAC-4 expression was significantly associated with the absence of organ metastases (p = 0.0453) and borderline with the absence of lymph node metastases (p = 0.0571) and tumor proliferative capacity (p = 0.0576). Enhanced HDAC-6 expression was significantly associated with earlier histopathological stage (p = 0.0115) and borderline with smaller tumor size (p = 0.0864). Pancreatic adenocarcinoma patients with enhanced HDAC-1 and -6 expression showed significantly longer survival times compared to those with low expression (p = 0.0022 and p = 0.0113, respectively), while a borderline association concerning HDAC-2 expression was noted (p = 0.0634).
CONCLUSIONS: The present study suggested that HDACs may be implicated in pancreatic malignant disease progression, being considered of clinical utility with potential use as therapeutic targets.
Liu ZH, Li J, Xia J, et al.Ginsenoside 20(s)-Rh2 as potent natural histone deacetylase inhibitors suppressing the growth of human leukemia cells.
Chem Biol Interact. 2015; 242:227-34 [PubMed
] Related Publications
BACKGROUND AND OBJECTIVE: Activation and abnormal expression of histone deacetylase (HDAC) which is important target for cancer therapeutics are related to the occurrence of human leukemia. 20(s)-Ginsenoside Rh2 (20(s)-Rh2) may be a potential HDAC inhibitor (HDACi) of leukemia, but the mechanism has not been reported.
METHODS: The cell proliferation and apoptosis was assessed in cultured K562 and KG-1α cells. The protein expression was measured with immunoblotting. The activities of HDAC and histone acetyltransferase (HAT) were measured with BCA. In vivo experiments were performed on naked mice carrying K562 cells for assessment of tumor growth, apoptosis, protein expression, and HDAC/HAT activities.
RESULTS: 20(s)-Rh2 effectively induced cell cycle arrest at G0/G1 phase and apoptosis in K562 and KG1-α cells, decreased the levels of proteins associated with cell proliferation (Cyclin D1, Bcl-2, ERK, p-ERK) and activated pro-apoptotic proteins (Bax, cleaved Caspase-3, p38, p-p38, JNK, p-JNK). 20(s)-Rh2 down-regulated HDAC1, HDAC2, HDAC6, increased histone H3 acetylation and HAT activity. Moreover, 20(s)-Rh2 inhibited the growth of human leukemia xenograft tumors in vivo.
CONCLUSION: 20(s)-Rh2 inhibited the proliferation of K562 and KG1-α cell by reducing the expression and activity of HDACs, increasing histone acetylation, and regulating key proteins in the downstream signaling pathways. Therefore, 20(s)-Rh2 could become a potential natural HDACi for chemotherapy of leukemia.
Histone deacetylase 6 (HDAC6) is a unique member of the histone deacetylase family. Although HDAC6 is mainly localized in the cytoplasm, it can regulate the activities of the transcription factors in the nucleus. However, a correlation of intracellular distribution of HDAC6 with tumor progression is lacking. In this study, we found that a low frequency of nuclear HDAC6-positive cells in tumors was associated with distant metastasis and a worse overall survival in 134 patients with non-small cell lung cancer (NSCLC). Ectopic expression of wild-type HDAC6 promoted migration and invasion of A549 and H661 cells. However, the enforced expression of nuclear export signal-deleted HDAC6 inhibited the invasion but not the migration of both cell lines. The inhibitory effect of nuclear HDAC6 on invasion was mediated by the deacetylation of the p65 subunit of nuclear factor-κB, which decreased its DNA-binding activity to the MMP2 promoter, leading to the downregulation of MMP2 expression. Our findings indicated that the loss of nuclear HDAC6 may be a potential biomarker for predicting metastasis in patients with NSCLC.
Many proteins are known to promote ciliogenesis, but mechanisms that promote primary cilia disassembly before mitosis are largely unknown. Here we identify a mechanism that favours cilium disassembly and maintains the disassembled state. We show that co-localization of the S/G2 phase kinase, Nek2 and Kif24 triggers Kif24 phosphorylation, inhibiting cilia formation. We show that Kif24, a microtubule depolymerizing kinesin, is phosphorylated by Nek2, which stimulates its activity and prevents the outgrowth of cilia in proliferating cells, independent of Aurora A and HDAC6. Our data also suggest that cilium assembly and disassembly are in dynamic equilibrium, but Nek2 and Kif24 can shift the balance toward disassembly. Further, Nek2 and Kif24 are overexpressed in breast cancer cells, and ablation of these proteins restores ciliation in these cells, thereby reducing proliferation. Thus, Kif24 is a physiological substrate of Nek2, which regulates cilia disassembly through a concerted mechanism involving Kif24-mediated microtubule depolymerization.
Aberrant activation of Janus kinase-3 (Jak3) and its key down-stream effectors, Signal Transducer and Activator of Transcription-3 (STAT3) and STAT5, is a key feature of malignant transformation in cutaneous T-cell lymphoma (CTCL). However, it remains only partially understood how Jak3/STAT activation promotes lymphomagenesis. Recently, non-coding microRNAs (miRNAs) have been implicated in the pathogenesis of this malignancy. Here, we show that (i) malignant T cells display a decreased expression of a tumor suppressor miRNA, miR-22, when compared to non-malignant T cells, (ii) STAT5 binds the promoter of the miR-22 host gene, and (iii) inhibition of Jak3, STAT3, and STAT5 triggers increased expression of pri-miR-22 and miR-22. Curcumin, a nutrient with anti-Jak3 activity and histone deacetylase inhibitors (HDACi) also trigger increased expression of pri-miR-22 and miR-22. Transfection of malignant T cells with recombinant miR-22 inhibits the expression of validated miR-22 targets including NCoA1, a transcriptional co-activator in others cancers, as well as HDAC6, MAX, MYCBP, PTEN, and CDK2, which have all been implicated in CTCL pathogenesis. In conclusion, we provide the first evidence that de-regulated Jak3/STAT3/STAT5 signalling in CTCL cells represses the expression of the gene encoding miR-22, a novel tumor suppressor miRNA.
Li S, Liu X, Chen X, et al.Histone deacetylase 6 promotes growth of glioblastoma through inhibition of SMAD2 signaling.
Tumour Biol. 2015; 36(12):9661-5 [PubMed
] Related Publications
Histone deacetylases (HDACs) play a role in the tumorigenesis of glioblastoma multiforme (GBM), whereas the underlying mechanism has not been elucidated. Here, we reported significantly higher HDAC6 levels in GBM from the patients. GBM cell growth was significantly inhibited by ACY-1215, a specific HDAC6 inhibitor. Further analyses show that HDAC6 may promote growth of GBM cells through inhibition of SMAD2 phosphorylation to downregulate p21. Thus, our data demonstrate a previously unrecognized regulation pathway in that HDAC6 increases GBM growth through attenuating transforming growth factor β (TGFβ) receptor signaling.
Chang YW, Tseng CF, Wang MY, et al.Deacetylation of HSPA5 by HDAC6 leads to GP78-mediated HSPA5 ubiquitination at K447 and suppresses metastasis of breast cancer.
Oncogene. 2016; 35(12):1517-28 [PubMed
] Related Publications
Heat-shock protein 5 (HSPA5) is a marker for poor prognosis in breast cancer patients and has an important role in cancer progression, including promoting drug resistance and metastasis. In this study, we identify that the specific lysine residue 447 (K447) of HSPA5 could be modified with polyubiquitin for subsequent degradation through the ubiquitin proteasomal system, leading to the suppression of cell migration and invasion of breast cancer. We further found that GP78, an E3 ubiquitin ligase, interacted with the C-terminal region of HSPA5 and mediated HSPA5 ubiquitination and degradation. Knock down of GP78 significantly increased the expression of HSPA5 and enhanced migration/invasive ability of breast cancer cells. Knock down of histone deacetylase-6 (HDAC6) increased the acetylation of HSPA5 at lysine residues 353 (K353) and reduced GP78-mediated ubiquitination of HSPA5 at K447 and then increased cell migration/invasion. In addition, we demonstrate that E3 ubiquitin ligase GP78 preferentially binds to deacetylated HSPA5. Notably, the expression levels of GP78 inversely correlated with HSPA5 levels in breast cancer patients. Patients with low GP78 expression significantly correlated with invasiveness of breast cancer, advanced tumor stages and poor clinical outcome. Taken together, our results provide new mechanistic insights into the understanding that deacetylation of HSPA5 by HDAC6 facilitates GP78-mediated HSPA5 ubiquitination and suggest that post-translational regulation of HSPA5 protein is critical for HSPA5-mediated metastatic properties of breast cancer.
Lv Z, Weng X, Du C, et al.Downregulation of HDAC6 promotes angiogenesis in hepatocellular carcinoma cells and predicts poor prognosis in liver transplantation patients.
Mol Carcinog. 2016; 55(5):1024-33 [PubMed
] Related Publications
HDAC6, a member of histone deacetylation family, is reported to play critical roles in transcription regulation, cell cycle progression, and cancer development. However, the expression status and significance of HDAC6 in hepatocellular carcinoma (HCC) is still controversial, and little is known about the role of HDAC6 in HCC angiogenesis and the correlation between expression of HDAC6 and prognosis of HCC patients with liver transplantation (LT). Our experiments showed HDAC6 was significantly downregulated in HCC tissues (P = 0.025), and low expression of HDAC6 was found to be closely associated with recurrence (P = 0.006), and could predict poor recurrence-free survival (P = 0.047) for HCC patients with LT. Moreover, knockdown of HDAC6 could promote HUVEC migration, proliferation, and tube formation in vitro, and suppress HCC cell apoptosis, and promote HCC cell proliferation in hypoxia. Remarkably, knockdown of HDAC6 could significantly up-regulate the expression of HIF-1α and VEGFA in vivo and in vitro, which facilitated HIF-1α mediated angiogenesis in HCC. Further study showed that HDAC6 was down-regulated under hypoxia in a time dependent manner. Hence, the present findings suggested a role for suppression of HDAC6 in promoting the angiogenesis in HCC by HIF-1α/VEGFA axis. HDAC6 may serve as a recurrence predictive factor for HCC after LT and pharmacological or genetic activation of HDAC6 could be a novel anti-angiogenesis approach for HCC therapy.
Missense mutations in p53 generate aberrant proteins with abrogated tumour suppressor functions that can also acquire oncogenic gain-of-function activities that promote malignant progression, invasion, metastasis and chemoresistance. Mutant p53 (mutp53) proteins undergo massive constitutive stabilization specifically in tumours, which is the key requisite for the acquisition of gain-of-functions activities. Although currently 11 million patients worldwide live with tumours expressing highly stabilized mutp53, it is unknown whether mutp53 is a therapeutic target in vivo. Here we use a novel mutp53 mouse model expressing an inactivatable R248Q hotspot mutation (floxQ) to show that tumours depend on sustained mutp53 expression. Upon tamoxifen-induced mutp53 ablation, allotransplanted and autochthonous tumours curb their growth, thus extending animal survival by 37%, and advanced tumours undergo apoptosis and tumour regression or stagnation. The HSP90/HDAC6 chaperone machinery, which is significantly upregulated in cancer compared with normal tissues, is a major determinant of mutp53 stabilization. We show that long-term HSP90 inhibition significantly extends the survival of mutp53 Q/- (R248Q allele) and H/H (R172H allele) mice by 59% and 48%, respectively, but not their corresponding p53(-/-) littermates. This mutp53-dependent drug effect occurs in H/H mice treated with 17DMAG+SAHA and in H/H and Q/- mice treated with the potent Hsp90 inhibitor ganetespib. Notably, drug activity correlates with induction of mutp53 degradation, tumour apoptosis and prevention of T-cell lymphomagenesis. These proof-of-principle data identify mutp53 as an actionable cancer-specific drug target.
Shen M, Duan WM, Wu MY, et al.Participation of autophagy in the cytotoxicity against breast cancer cells by cisplatin.
Oncol Rep. 2015; 34(1):359-67 [PubMed
] Related Publications
Breast cancer is one of the most common cancers affecting women worldwide. Conventional chemotherapy is still one of the major approaches to the treatment of breast cancer. Autophagy, also termed as type II programmed cell death (PCD), exhibits either a protumorigenic or antitumorigenic function. In the present study, we investigated whether autophagy could be involved in the effect of chemotherapy against breast cancer. Epirubicin, docetaxel, methotrexate, cyclophosphamide, fluorouracil (5-FU) and cisplatin were applied in the present investigation. All of these chemotherapeutics presented cytotoxicity against breast cancer cells. DsRed-LC3 reporter assay revealed that only docetaxel and cisplatin induced autophagy. Autophagy inhibitor 3-methyladenine (3-MA) strengthened the cytotoxicity of docetaxel, yet impaired the cytotoxicity of cisplatin, suggesting that docetaxel stimulates protumorigenic autophagy, while cisplatin-induced autophagy could be antitumorigenic. Real-time PCR revealed that cisplatin upregulated multiple autophagy-related genes, including AMBRA1, ATG3, ATG4C, ATG4D, ATG5, ATG7, ATG13, ATG14, ATG16L2, Beclin1, DRAM1, GABARAP, GABARAPL1, GABARAPL2, HDAC6, IRGM, MAP1LC3B and ULK1, indicating that cisplatin induced autophagy through a multiple mechanism involved manner.
Here we found loss of c-Cbl, an E3 ligase, expression in non-small cell lung cancer (NSCLC) compared with its adjacent normal tissue in patient specimens. HDAC inhibition by WJ or knockdown of HDAC 1, HDAC2, HDAC3 or HDAC6 all induced c-Cbl. Ectopic expression of c-Cbl induced decreased EGFR, inhibited growth in NSCLC cells. Knockdown of EGFR inhibited NSCLC growth. Mutation of EGFR at Y1045 decreased WJ-induced growth inhibition as well as in vivo anti-cancer effect and EGFR degradation mediated by WJ. Time-lapse confocal analysis showed co-localization of c-Cbl and EGFR after WJ treatment. Furthermore, WJ inhibited lung tumor growth through c-Cbl induction in orthotopic and tail vein injected models. C-Cbl up-regulation induced by HDACi is a potential strategy for NSCLC treatment.
Sen A, Nelson TJ, Alkon DLApoE4 and Aβ Oligomers Reduce BDNF Expression via HDAC Nuclear Translocation.
J Neurosci. 2015; 35(19):7538-51 [PubMed
] Related Publications
Apolipoprotein E4 (ApoE4) is a major genetic risk factor for several neurodegenerative disorders, including Alzheimer's disease (AD). Epigenetic dysregulation, including aberrations in histone acetylation, is also associated with AD. We show here for the first time that ApoE4 increases nuclear translocation of histone deacetylases (HDACs) in human neurons, thereby reducing BDNF expression, whereas ApoE3 increases histone 3 acetylation and upregulates BDNF expression. Amyloid-β (Aβ) oligomers, which have been implicated in AD, caused effects similar to ApoE4. Blocking low-density lipoprotein receptor-related protein 1 (LRP-1) receptor with receptor-associated protein (RAP) or LRP-1 siRNA abolished the ApoE effects. ApoE3 also induced expression of protein kinase C ε (PKCε) and PKCε retained HDACs in the cytosol. PKCε activation and ApoE3 supplementation prevented ApoE4-mediated BDNF downregulation. PKCε activation also reversed Aβ oligomer- and ApoE4-induced nuclear import of HDACs, preventing the loss in BDNF. ApoE4 induced HDAC6-BDNF promoter IV binding, which reduced BDNF exon IV expression. Nuclear HDAC4 and HDAC6 were more abundant in the hippocampus of ApoE4 transgenic mice than in ApoE3 transgenic mice or wild-type controls. Nuclear translocation of HDA6 was also elevated in the hippocampus of AD patients compared with age-matched controls. These results provide new insight into the cause of synaptic loss that is the most important pathologic correlate of cognitive deficits in AD.
Cancer progression requires a significant reprogramming of cellular signaling to support the essential tumor-specific processes that include hyperproliferation, invasion (for solid tumors) and survival of metastatic colonies. NEDD9 (also known as CasL and HEF1) encodes a multi-domain scaffolding protein that assembles signaling complexes regulating multiple cellular processes relevant to cancer. These include responsiveness to signals emanating from the T and B cell receptors, integrins, chemokine receptors, and receptor tyrosine kinases, as well as cytoplasmic oncogenes such as BCR-ABL and FAK- and SRC-family kinases. Downstream, NEDD9 regulation of partners including CRKL, WAVE, PI3K/AKT, ERK, E-cadherin, Aurora-A (AURKA), HDAC6, and others allow NEDD9 to influence functions as pleiotropic as migration, invasion, survival, ciliary resorption, and mitosis. In this review, we summarize a growing body of preclinical and clinical data that indicate that while NEDD9 is itself non-oncogenic, changes in expression of NEDD9 (most commonly elevation of expression) are common features of tumors, and directly impact tumor aggressiveness, metastasis, and response to at least some targeted agents inhibiting NEDD9-interacting proteins. These data strongly support the relevance of further development of NEDD9 as a biomarker for therapeutic resistance. Finally, we briefly discuss emerging evidence supporting involvement of NEDD9 in additional pathological conditions, including stroke and polycystic kidney disease.
Wang XC, Ma Y, Meng PS, et al.miR-433 inhibits oral squamous cell carcinoma (OSCC) cell growth and metastasis by targeting HDAC6.
Oral Oncol. 2015; 51(7):674-82 [PubMed
] Related Publications
OBJECTIVES: The aim of this study was to determine expression levels of miR-433 in oral squamous cell carcinomas (OSCCs) and adjacent normal tissues, and explore its biological functions in OSCCs.
METHODS: miR-433 level in oral squamous cell carcinomas (OSCCs) and adjacent normal tissues was tested by real-time qPCR. The effect of miR-433 on cell growth was detected by MTT and colony formation assays. The tumorigenicity of miR-433 transfected OSCCs was evaluated in nude mice model. Transwell and wound healing assays were performed to detect the effect of miR-433 on OSCCs cell invasion and migration. Luciferase reporter gene assays were performed to identify the interaction between miR-433 and 3'UTR of HDAC6 mRNA. The protein level of HDAC6, BCL2, CCNE1, MMP1 and MMP9 was determined by Western blotting. Immunohistochemistry analysis was performed to detect the expression of HDAC6 in oral squamous cell carcinomas (OSCCs) and adjacent normal tissues.
RESULTS: We found that miR-433 was frequently down-regulated in OSCCs compared with adjacent normal tissues. Restoring miR-433 expression in OSCC cells dramatically suppressed cells growth, invasion and migration. Importantly, our data showed that miR-433 downregulated the expression of HDAC6 through directly targeting its 3'UTR.
CONCLUSION: Our data suggest that miR-433 exerts its tumor suppressor function by targeting HDAC6, leading to the inhibition of OSCC cell growth, invasion and migration, which suggest that miR-433 may be potential target for diagnostic and therapeutic applications in OSCC.
Dali-Youcef N, Froelich S, Moussallieh FM, et al.Gene expression mapping of histone deacetylases and co-factors, and correlation with survival time and 1H-HRMAS metabolomic profile in human gliomas.
Sci Rep. 2015; 5:9087 [PubMed
] Free Access to Full Article Related Publications
Primary brain tumors are presently classified based on imaging and histopathological techniques, which remains unsatisfaying. We profiled here by quantitative real time PCR (qRT-PCR) the transcripts of eighteen histone deacetylases (HDACs) and a subset of transcriptional co-factors in non-tumoral brain samples from 15 patients operated for epilepsia and in brain tumor samples from 50 patients diagnosed with grade II oligodendrogliomas (ODII, n = 9), grade III oligodendrogliomas (ODIII, n = 22) and glioblastomas (GL, n = 19). Co-factor transcripts were significantly different in tumors as compared to non-tumoral samples and distinguished different molecular subgroups of brain tumors, regardless of tumor grade. Among all patients studied, the expression of HDAC1 and HDAC3 was inversely correlated with survival, whereas the expression of HDAC4, HDAC5, HDAC6, HDAC11 and SIRT1 was significantly and positively correlated with survival time of patients with gliomas. (1)H-HRMAS technology revealed metabolomically distinct groups according to the expression of HDAC1, HDAC4 and SIRT1, suggesting that these genes may play an important role in regulating brain tumorigenesis and cancer progression. Our study hence identified different molecular fingerprints for subgroups of histopathologically similar brain tumors that may enable the prediction of outcome based on the expression level of co-factor genes and could allow customization of treatment.
Previous studies have shown that histone deacetylase 6 (HDAC6) plays critical roles in many cellular processes related to cancer. However, its biological roles in the development of melanoma remain unexplored. Our aim was to investigate whether HDAC6 has a biological role in human melanoma development and to understand its underlying mechanism. In the present study, HDAC6 expression was up-regulated in melanoma tissues and cell lines. Knockdown of HDAC6 significantly inhibited the proliferation and colony formation ability of A375.S2 cells, promoted cell arrest at G0/G1 phase and apoptosis. Additionally, western blotting assay showed that HDAC6 silencing suppressed Bcl-2 level and enhanced Bax level, then activated caspase-9 and caspase-3, and further activated the release of cytochrome c from mitochondria to cytoplasm, finally induced cell apoptosis involving the mitochondrial pathway. Knockdown of HDAC6 triggered a significant generation of ROS and disruption of mitochondrial membrane potential (MMP). Furthermore, ROS inhibitor, NAC reduced HDAC6 siRNA-induced ROS production, and blocked HDAC6 siRNA-induced loss of MMP and apoptosis. NAC also significantly blocked HDAC6 siRNA-induced mtDNA copy number decrease and mitochondrial biogenesis and degradation imbalance. In conclusion, the results showed that knockdown of HDAC6 induced apoptosis in human melanoma A375.S2 cells through a ROS-dependent mitochondrial pathway.
Recently, we reported that induction of the co-chaperone Bcl-2-associated athanogene 3 (BAG3) is critical for recovery of rhabdomyosarcoma (RMS) cells after proteotoxic stress upon inhibition of the two constitutive protein degradation pathways, that is, the ubiquitin-proteasome system by Bortezomib and the aggresome-autophagy system by histone deacetylase 6 (HDAC6) inhibitor ST80. In the present study, we investigated the molecular mechanisms mediating BAG3 induction under these conditions. Here, we identify nuclear factor-kappa B (NF-κB)-inducing kinase (NIK) as a key mediator of ST80/Bortezomib-stimulated NF-κB activation and transcriptional upregulation of BAG3. ST80/Bortezomib cotreatment upregulates mRNA and protein expression of NIK, which is accompanied by an initial increase in histone H3 acetylation. Importantly, NIK silencing by siRNA abolishes NF-κB activation and BAG3 induction by ST80/Bortezomib. Furthermore, ST80/Bortezomib cotreatment stimulates NF-κB transcriptional activity and upregulates NF-κB target genes. Genetic inhibition of NF-κB by overexpression of dominant-negative IκBα superrepressor (IκBα-SR) or by knockdown of p65 blocks the ST80/Bortezomib-stimulated upregulation of BAG3 mRNA and protein expression. Interestingly, inhibition of lysosomal activity by Bafilomycin A1 inhibits ST80/Bortezomib-stimulated IκBα degradation, NF-κB activation and BAG3 upregulation, indicating that IκBα is degraded via the lysosome in the presence of Bortezomib. Thus, by demonstrating a critical role of NIK in mediating NF-κB activation and BAG3 induction upon ST80/Bortezomib cotreatment, our study provides novel insights into mechanisms of resistance to proteotoxic stress in RMS.
Xia Q, Wang H, Zhang Y, et al.Loss of TDP-43 Inhibits Amyotrophic Lateral Sclerosis-Linked Mutant SOD1 Aggresome Formation in an HDAC6-Dependent Manner.
J Alzheimers Dis. 2015; 45(2):373-86 [PubMed
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Amyotrophic lateral sclerosis (ALS) is a fatal, adult-onset, and progressive neurodegenerative disorder with no cure. Cu/Zn-superoxide dismutase (SOD1) was the first identified protein associated with familial ALS; and aggresome formation of misfolded SOD1 is closely associated with ALS pathogenesis. HDAC6, one of the histone deacetylase family members, has already been demonstrated to play an important role in regulating aggresome formation of misfolded proteins and protecting cells against the toxicity induced by misfolded proteins. In this study, we found that in a cellular model with impaired proteasome activity, the TAR DNA-binding protein 43, which is closely linked with ALS and associated with various neurodegenerative disorders such as frontotemporal lobar degeneration, Alzheimer’s disease, and Parkinson’s disease, can regulate mutant SOD1 aggresome formation through an HDAC6-dependent manner. TDP-43 deficiency did not affect poly-ubiquitination of mutant SOD1, whereas it greatly decreased the expression level of HDAC6, which is required for aggresome formation of ALS-linked mutant SOD1. Moreover, overexpression of siRNA-resistant HDAC6 restored mutant SOD1 aggresome formation in TDP-43-knockdown cells. Thus, our data provide evidence that TDP-43 plays an important role in mutant SOD1 aggresome formation through its regulation of HDAC6.
Neuroblastoma is one of the most prevalent pediatric extracranial solid tumors and is often diagnosed after dissemination has occurred. Despite recent advances in multimodal therapies of this malignancy, its therapeutic efficacy remains poor. Novel treatment strategies are thus in great need. Herein, we demonstrate that histone deacetylase 6 (HDAC6), a member of the deacetylase family that is localized predominantly in the cytoplasm, is involved in neuroblastoma dissemination. HDAC6 expression in neuroblastoma tissue samples varied with the site of the tumor. HDAC6 showed little impact on the proliferation of neuroblastoma cells. Instead, downregulation of HDAC6 expression by RNA interference or inhibition of its catalytic activity by the pharmacological inhibitor tubacin significantly decreased the migration of 3 human malignant neuroblastoma cell lines and reduced the invasion ability of one of the 3 cell lines, but only slightly affected the migration and invasion of human normal brain glial cells. Our data further revealed that the regulation of neuroblastoma cell migration by HDAC6 was mediated by its effects on cell polarization and adhesion. These findings suggest a role for HDAC6 in neuroblastoma dissemination and a potential of using HDAC6 inhibitors for the treatment of this malignancy.
Histone deacetylases (HDAC) control gene expression through their ability to acetylate proteins, thereby influencing a diverse range of cellular functions. Class I HDAC (HDAC1-3 and 8) and HDAC6 are predominantly upregulated in malignancies and their altered expression in some cancers has a significant prognostic implication. The expression and prognostic consequence of dysregulated Class I HDAC and HDAC6, key players in multiple myeloma (MM), are unknown. This study hypothesized that HDAC are dysregulated in MM and patients with high expression have significantly poorer prognostic outcomes. Quantitative PCR for 11 HDAC (Class I, II, and IV) was performed in genetically heterogeneous human myeloma cell lines (HMCL) and primary MM and compared to normal plasma cells (PC). In HMCL, HDAC1-3 and 8 (Class I), and HDAC5 and HDAC10 (Class II) were significantly upregulated compared to normal PC. In primary MM, the median expression level of all of the HDAC, except HDAC1 and HDAC11, were elevated when compared to normal PC. Patients with higher levels of HDAC1-3, HDAC4, HDAC6, and HDAC11 transcripts demonstrated a significantly shorter progression-free survival (PFS). Immunohistochemical staining for HDAC1 and HDAC6 on bone marrow trephines from a uniformly treated cohort of transplant eligible MM patients revealed that HDAC1 protein was detectable in most patients and that higher levels of MM cell HDAC1 protein expression (≥90 % versus ≤20 % MM cell positivity) correlated with both shorter PFS (P = 0 .07) and shorter overall survival (P = 0 .003). Conversely, while the majority of patients expressed HDAC6, there was no correlation between HDAC6 levels and patient outcome. Together, these results indicate that overexpression of Class I HDAC, particularly HDAC1, is associated with poor prognosis in MM.
Moriya S, Komatsu S, Yamasaki K, et al.Targeting the integrated networks of aggresome formation, proteasome, and autophagy potentiates ER stress‑mediated cell death in multiple myeloma cells.
Int J Oncol. 2015; 46(2):474-86 [PubMed
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The inhibitory effects of macrolide antibiotics including clarithromycin (CAM) on autophagy flux have been reported. Although a macrolide antibiotic exhibits no cytotoxicity, its combination with bortezomib (BZ), a proteasome inhibitor, for the simultaneous blocking of the ubiquitin (Ub)‑proteasome and autophagy‑lysosome pathways leads to enhanced multiple myeloma (MM) cell apoptosis induction via stress overloading of the endoplasmic reticulum (ER). As misfolded protein cargo is recruited by histone deacetylase 6 (HDAC6) to dynein motors for aggresome transport, serving to sequester misfolded proteins, we further investigated the cellular effects of targeting proteolytic pathways and aggresome formation concomitantly in MM cells. Pronounced apoptosis was induced by the combination of vorinostat [suberoylanilide hydroxamic acid (SAHA); potently inhibits HDAC6] with CAM and BZ compared with each reagent or a 2‑reagent combination. CAM/BZ treatment induced vimentin positive‑aggresome formation along with the accumulation of autolysosomes in the perinuclear region, whereas they were inhibited in the presence of SAHA. The SAHA/CAM/BZ combination treatment maximally upregulated genes related to ER stress including C/EBP homologous protein (CHOP). Similarly to MM cell lines, enhanced cytotoxicity with CHOP upregulation following SAHA/CAM/BZ treatment was shown by a wild‑type murine embryonic fibroblast (MEF) cell line; however, a CHOP‑deficient MEF cell line almost completely canceled this pronounced cytotoxicity. Knockdown of HDAC6 with siRNA exhibited further enhanced CAM/BZ‑induced cytotoxicity and CHOP induction along with the cancellation of aggresome formation. Targeting the integrated networks of aggresome, proteasome, and autophagy is suggested to induce efficient ER stress‑mediated apoptosis in MM cells.
Lakshmaiah KC, Jacob LA, Aparna S, et al.Epigenetic therapy of cancer with histone deacetylase inhibitors.
J Cancer Res Ther. 2014 Jul-Sep; 10(3):469-78 [PubMed
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Epigenetics is the study of heritable alterations in gene expression that are not accompanied by the corresponding change in DNA sequence. Three interlinked epigenetic processes regulate gene expression at the level of chromatin, namely DNA methylation, nucleosomal remodeling and histone covalent modifications. Post-translational modifications that occur on certain amino acid residues of the tails of histone proteins modify chromatin structure and form the basis for "histone code". The enzymes Histone Acetyl Transferase (HAT) and Histone Deacetylase (HDAC) control the level of acetylation of histones and thereby alter gene expression. In many cancers, the balance between HAT and HDAC is altered. HDAC enzymes are grouped into four different classes namely Class I (HDAC1, HDAC2, HDAC3, and HDAC8), Class II (HDAC4, HDAC5, HDAC6, HDAC7, HDAC9, and HDAC10), Class III HDAC and Class IV (HDAC11). Histone Deacetylase Inhibitors (HDACI) exert anticancer activity by promoting acetylation of histones as well as by promoting acetylation of non-histone protein substrates. The effects of HDACI on gene transcription are complex. They cause cell cycle arrest, inhibit DNA repair, induce apoptosis and acetylate non histone proteins causing downstream alterations in gene expression. HDACI are a diverse group of compounds, which vary in structure, biological activity, and specificity. In general, HDACIs contain a zinc-binding domain, a capping group, and a straight chain linker connecting the two. They are classified into four classes namely short chain fatty acids, hydroxamic acids, cyclic peptides and synthetic benzamides. This review describes the clinical utility of HDACI as monotherapy as well as combination therapy with other treatment modalities such as chemotherapy and radiotherapy. Adverse effects and shortcomings of treatment with HDACI are also discussed in detail.