Structurally novel HDAC inhibitors based on the trans-β-arylacryl tetrahydroisoquinoline scaffold: the design, synthesis, and anti-cancer activity / 药学学报

In this study, a series of 18 histone deacetylases inhibitors (HDACis), derived from our in-house anti-cancer trans-β-arylacryl 1,2,3,4-tetrahydroisoquinoline-based scaffold, were designed, synthesized, and antitumor evaluated. HDAC1 inhibitory activity assay showed that compounds 13d-13f and 13m-13o demonstrated attractive enzymatic activity with IC50 at single-digit nanomolar or subnanomolar level.In addition, 13o exerted superior anti-proliferative activity (A549, IC50 = 0.89 μmol·L-1; HCT116, IC50 = 0.49 μmol·L-1) to that of vorinostat (SAHA).Besides,13e, with the most potent HDAC1 enzymatic activity (IC50 = 3.8 nmol·L-1), also displayed attractive cellular activity (A549, IC50 = 1.74 μmol·L-1; HCT116, IC50 = 2.43 μmol·L-1). The Western blot analysis illustrated that 13e treatment increased the acetylation of H3 and α-tubulin in a dose-dependent manner in A549 cells. In summary, 13e and 13o deserve further functional investigation.

Advances in anti-tumor research of HDAC inhibitors and combination with PI3K inhibitors / 药学学报

Histone deacetylase (HDAC) is usually abnormally overexpressed, which mainly leads to the transcriptional repression of tumor suppressor genes. Histone deacetylase inhibitors (HDIs) exert anti-tumor biological effects by regulating nucleosome structure, inhibiting HDAC activity, and controlling the expression of tumor suppressor genes. There are currently 5 drugs on the market, but only for peripheral T-cell lymphoma and cutaneous T-cell lymphoma. In solid tumors, most of the HDAC inhibitors used have failed to achieve effective therapeutic effects. Phosphoinositide 3-kinase (PI3K) is the starting node of the PI3K-AKT-mTOR signaling pathway, which plays a very important role in the proliferation, migration, invasion, and differentiation of tumor cells. The abnormal activation of PI3K is closely related to the occurrence and development of tumors, and the combined use of HDAC and PI3K inhibitors and HDAC/PI3K dual-target inhibitors show synergistic anticancer activity. This article introduces the anti-tumor clinical and preclinical research progress of representative HDAC inhibitors and PI3K inhibitors, as well as HDAC/PI3K dual-target inhibitors.

Chidamide inhibits the NOTCH1-MYC signaling axis in T-cell acute lymphoblastic leukemia / 医学前沿

T-cell acute lymphoblastic leukemia (T-ALL) is one of the most dangerous hematological malignancies, with high tumor heterogeneity and poor prognosis. More than 60% of T-ALL patients carry NOTCH1 gene mutations, leading to abnormal expression of downstream target genes and aberrant activation of various signaling pathways. We found that chidamide, an HDAC inhibitor, exerts an antitumor effect on T-ALL cell lines and primary cells including an anti-NOTCH1 activity. In particular, chidamide inhibits the NOTCH1-MYC signaling axis by down-regulating the level of the intracellular form of NOTCH1 (NICD1) as well as MYC, partly through their ubiquitination and degradation by the proteasome pathway. We also report here the preliminary results of our clinical trial supporting that a treatment by chidamide reduces minimal residual disease (MRD) in patients and is well tolerated. Our results highlight the effectiveness and safety of chidamide in the treatment of T-ALL patients, including those with NOTCH1 mutations and open the way to a new therapeutic strategy for these patients.

HDAC inhibitors overcome immunotherapy resistance in B-cell lymphoma

Immunotherapy has been applied successfully to treat B-cell lymphomas in preclinical models or clinical settings. However, immunotherapy resistance is a major challenge for B-cell lymphoma treatment. To overcome this issue, combinatorial therapeutic strategies have been pursued to achieve a better efficacy for treating B-cell lymphomas. One of such strategies is to combine immunotherapy with histone deacetylase (HDAC) inhibitors. HDAC inhibitors can potentially increase tumor immunogenicity, promote anti-tumor immune responses, or reverse immunosuppressive tumor environments. Thus, the combination of HDAC inhibitors and immunotherapy has drawn much attention in current cancer treatment. However, not all HDAC inhibitors are created equal and their net effects are highly dependent on the specific inhibitors used and the HDACs they target. Hence, we suggest that optimal treatment efficacy requires personalized design and rational combination based on prognostic biomarkers and unique profiles of HDAC inhibitors. Here, we discuss the possible mechanisms by which B-cell lymphomas acquire immunotherapy resistance and the effects of HDAC inhibitors on tumor cells and immune cells that could help overcome immunotherapy resistance.

HDAC inhibitors overcome immunotherapy resistance in B-cell lymphoma

Immunotherapy has been applied successfully to treat B-cell lymphomas in preclinical models or clinical settings. However, immunotherapy resistance is a major challenge for B-cell lymphoma treatment. To overcome this issue, combinatorial therapeutic strategies have been pursued to achieve a better efficacy for treating B-cell lymphomas. One of such strategies is to combine immunotherapy with histone deacetylase (HDAC) inhibitors. HDAC inhibitors can potentially increase tumor immunogenicity, promote anti-tumor immune responses, or reverse immunosuppressive tumor environments. Thus, the combination of HDAC inhibitors and immunotherapy has drawn much attention in current cancer treatment. However, not all HDAC inhibitors are created equal and their net effects are highly dependent on the specific inhibitors used and the HDACs they target. Hence, we suggest that optimal treatment efficacy requires personalized design and rational combination based on prognostic biomarkers and unique profiles of HDAC inhibitors. Here, we discuss the possible mechanisms by which B-cell lymphomas acquire immunotherapy resistance and the effects of HDAC inhibitors on tumor cells and immune cells that could help overcome immunotherapy resistance.

Histone deacetylase inhibition attenuates hepatic steatosis in rats with experimental Cushing's syndrome

Cushing's syndrome (CS) is a collection of symptoms caused by prolonged exposure to excess cortisol. Chronically elevated glucocorticoid (GC) levels contribute to hepatic steatosis. We hypothesized that histone deacetylase inhibitors (HDACi) could attenuate hepatic steatosis through glucocorticoid receptor (GR) acetylation in experimental CS. To induce CS, we administered adrenocorticotropic hormone (ACTH; 40 ng/kg/day) to Sprague-Dawley rats by subcutaneous infusion with osmotic mini-pumps. We administered the HDACi, sodium valproate (VPA; 0.71% w/v), in the drinking water. Treatment with the HDACi decreased steatosis and the expression of lipogenic genes in the livers of CS rats. The enrichment of GR at the promoters of the lipogenic genes, such as acetyl-CoA carboxylase (Acc), fatty acid synthase (Fasn), and sterol regulatory element binding protein 1c (Srebp1c), was markedly decreased by VPA. Pan-HDACi and an HDAC class I-specific inhibitor, but not an HDAC class II a-specific inhibitor, attenuated dexamethasone (DEX)-induced lipogenesis in HepG2 cells. The transcriptional activity of Fasn was decreased by pretreatment with VPA. In addition, pretreatment with VPA decreased DEX-induced binding of GR to the glucocorticoid response element (GRE). Treatment with VPA increased the acetylation of GR in ACTH-infused rats and DEX-induced HepG2 cells. Taken together, these results indicate that HDAC inhibition attenuates hepatic steatosis hrough GR acetylation in experimental CS.

Antitumor effects and the mechanisms of dual-targeting drug NL-101 on human multiple myeloma / 中国药科大学学报

The antitumor activities of NL-101,aHDACi/DNA damage dual-targeting drug,on human multiple myeloma in vitro and in vivo were studied.Furthermore,the primary mechanisms were revealed.We detected the anti-proliferative activity of NL-101 on 10 human multiple myeloma cell lines,and the combinational effect of NL-101 and bortezomib on RPMI 8226 cell line.The inducing effects of NL-101 on cell cycle arrest and apoptosis were detected by FACS.The effects of NL-101 on acetyled-Histone H3,total Histone H3,acetyled α-Tubulin,total α-Tubulin,phospho-Histone H2A.X and total Histone H2A.X were evaluated by Western blott.We also demonstrated the antitumor activity of NL-101 and the combinational effect of NL-101 and bortezomib on RPMI 8226 xenograft tumor model in vivo.Results showed that NL-101 possessed strong antitumor activities on human multiple myeloma cells in vitro and in vivo.NL-101exhibited significant HDAC inhibitory activity and DNA alkylating activity.NL-101not only inhibited histone deacetylation level,but also increased the DNA damage in multiple myeloma cells.Meanwhile,NL-101 induced cell cycle arrest and apoptosis.Also,the synergistic effect of NL-101 was discovered when combined with bortezomib in vitro and in vivo.These data demonstrated that NL-101 may be a potent agent for the treatment of human multiple myeloma in future.

Histone deacetylase inhibitor down-regulated the expression of HER-2 in breast cancer through the changes in miRNA / 中国肿瘤临床

Objective:To investigate the mechanism of histone deacetylase (HDAC) inhibitor in down-regulating the expression of HER-2 in breast cancer cells and to provide an innovative therapeutic option to overcome the disadvantages of anti-HER-2 therapy. Meth-ods:HER-2-positive breast cell lines were treated with HDAC inhibitors. The changes in the gene and protein levels of HER-2 were de-tected by qPCR and Western blot. MiRNA microarray was used to identify the HDAC inhibitors, whereas qPCR was used to verify the miRNA expression. Results:In vitro cell experiments confirmed that the HDAC inhibitors TSA and SAHA can down-regulate the expres-sion of HER-2 in breast cancer cell lines. TSA can down-regulate the expression of HER-2 gene in BT474 and decrease the concentra-tions of 100 nmol by 10.7%and 200 nmol by 38.9%(P<0.05). TSA had no effect on the primary cells. The expression of HER-2 gene of BT474 was down-regulated by 93.9%(P<0.05) in the 5μmol/L group but not in the 1μmol/L group. SAHA significantly affected the pri-mary cells at a concentration of 1μmol/L and reduced the cells at 87.1%at a concentration of 5μmol/L. Seven miRNAs were identified from the miRNA microarray. MiR-762 was used as a basis to identify the changes in miRNA. The miRNA sputum identified by miRNA microarray and qPCR may be associated with the down-regulation of HER-2 by HDAC inhibitors. Conclusion: HDAC inhibitors may down-regulate the expression of HER-2 in breast cancer cells by changing some miRNAs.

Effect of suberoylanilide hydroxamic acid on diastolic dysfunction in restrictive cardiomyopathy mice / 解放军医学杂志

Objective To explore whether suberoylanilide hydroxamic acid (SAHA,br.Vorinostat,a kind of histone deacetylase inhibitor) can improve the diastolic function of restrictive cardiomyopathy (RCM) mice by up-regulating the expression of wild type cardiac troponin I (WT-cTnI).Methods Sixteen male cTnI R193H mice were employed and divided into SAHA group (n=6),dimethyl sulfoxide (DMSO) group (n=5) and control groups (n=5).Mice were subcutaneously injected with 50mg/kg SAHA in SAHA group,with 1ml/kg DMSO in DMSO group and with 1ml/kg normal saline in control group,respectively.The total treatment duration lasted for 56 days.Western blotting was performed to determine the levels of acetylated histone H3 (acH3) and the expression of cTnI.The transcription levels of Tnni3 were detected with RT-qPCR.The levels of acH3 in Tnni3 promoter key area were detected with chromatin immunoprecipitation (ChIP).The data of diastolic function measurements were collected using high frequency echocardiography.Results Compared to control group,the acH3 levels in nucleus and in Tnni3 promoter key area increased significantly in SAHA group (P＜0.05).The acH3 level showed no significant difference between SAHA group and DMSO group (P＞0.0S),but the specific acH3 level in Tnni3 promoter key area increased significantly in SAHA group compared to that in DMSO group (P＜0.05).The expression of cTnI protein and Tnni3 mRNA showed no significant difference among the 3 groups.Compared to the control group,Tei index and E/A ratio increased in DMSO group.Left ventricle fractional shortening (LVFS),left ventricle ejection fraction (LVEF),stroke volume (SV),cardiac output (CO),isovolumic relaxation time (IVRT),E peak deceleration time (DT),early diastolic blood flow (E velocity) and late diastolic filling flow (A velocity) showed no significant difference between DMSO group and control group.IVRT,DT and Tei index increased,and E velocity and A velocity decreased in SAHA group compared to that in control group.Furthermore,LVFS,LVEF,SV and CO were decreased in SAHA group compared to that in control group (P＜0.05).Similarly,IVRT increased (P＜0.05) and LVFS,LVEE CO,E velocity and E/A ratio decreased in SAHA group compared to that in DMSO group.Conclusions SAHA may up-regulate the acH3 level in GATA and MEF2 binding site of Tnni3 promoter of RCM mice.However,SAHA may have no effect on the expression and transcription of Tnni3 in heart.Further studies are needed to confirm whether SAHA has any toxic effect on cardiac function.

Effects of Trichostatin A on the Chondrogenesis from Human Mesenchymal Stem Cells

Histone deacetylase inhibitors (HDACi) are a class of compounds that suppress the function of histone deacetylases (HDACs). This study was performed to examine the effects of Trichostatin A (TSA), a typical HDACi, on chondrogenesis of human bone marrow mesenchymal stem cells (hBMMSCs) and related molecular pathways. After evaluating the concentration for cytotoxicity and HDAC activity, hBMMSCs underwent chondrogenic differentiation in pellet culture with or without TSA for 21 days. The weight of TSA-treated pellets was 25% lower than that of untreated pellets. DNA level was not significantly different, but glycosaminoglycan content per DNA level was lower in TSA-treated pellets than that of untreated pellets. Gene expression of the chondrogenic markers (SOX9, Aggrecan, and Col2A1) decreased by by 12.9-fold, 8.9-fold, and 7.6-fold respectively in TSA-treated pellets compared with that in TSA-untreated pellets. TSA-treated pellets had lower cell density and lower proteoglycan staining content compared with those of TSA-untreated pellets. A microarray analysis from TSA-treated pellets showed that 1,467 chondrogenic-related genes were downregulated and 1,524 were upregulated by more than 2-fold compared with TSA-untreated pellets. Col10A1, TGF-β3, and SOX9 decreased significantly by 10-fold, 2.1-fold, and 3.2-fold respectively in TSA-treated pellets compared with those in untreated pellets, whereas expression of BMP4 and FGFR3 increased significantly by 2.1-fold and 5.4-fold respectively. It is concluded that TSAinhibits chondrogenesis and does not seem to be useful for cartilage tissue engineering of hBMMSCs.

A New Histone Deacetylase Inhibitor, MHY219, Inhibits the Migration of Human Prostate Cancer Cells via HDAC1

Histone deacetylase (HDAC) inhibitors are considered novel agents for cancer chemotherapy. We previously investigated MHY219, a new HDAC inhibitor, and its potent anticancer activity in human prostate cancer cells. In the present study, we evaluated MHY219 molecular mechanisms involved in the regulation of prostate cancer cell migration. Similar to suberanilohydroxamic acid (SAHA), MHY219 inhibited HDAC1 enzyme activity in a dose-dependent manner. MHY219 cytotoxicity was higher in LNCaP (IC50=0.67 muM) than in DU145 cells (IC50=1.10 muM) and PC3 cells (IC50=5.60 muM) after 48 h of treatment. MHY219 significantly inhibited the HDAC1 protein levels in LNCaP and DU145 cells at high concentrations. However, inhibitory effects of MHY219 on HDAC proteins levels varied based on the cell type. MHY219 significantly inhibited LNCaP and DU145 cells migration by down-regulation of matrix metalloprotease-1 (MMP-1) and MMP-2 and induction of tissue inhibitor of metalloproteinases-1 (TIMP-1). These results suggest that MHY219 may potentially be used as an anticancer agent to block cancer cell migration through the repression of MMP-1 and MMP-2, which is related to the reduction of HDAC1.

Treatment strategies for Hodgkin lymphoma recurring following autologous hematopoietic stem cell transplantation

Hodgkin lymphoma (HL) represents one of the great success stories in hematology going from a uniformly fatal disease, to one that is curable in the vast majority of cases. Despite this success, some patients experience relapse. To address this unmet need a variety of agents, classes of drugs, and strategies have demonstrated activity in HL recurring after autologous hematopoietic stem cell transplantation. These include chemotherapeutics (gemcitabine-based combinations, bendamustine), histone deacetylase (HDAC) inhibitors (panobinostat), immunomodulatory agents (lenalidomide), mTOR inhiobitors (everolimus), monoclonal antibodies (rituximab), and antibody-drug conjugates (brentuximab vedotin) as well the potential of long-term disease control via allogeneic transplantation. Such advances reflect our increased understanding of the biology of HL and hold promise for continued improved outcomes for those suffering with this condition.

The Neuroprotective Effect of Treatment of Valproic Acid in Acute Spinal Cord Injury

OBJECTIVE: Valproic acid (VPA), as known as histone deacetylase inhibitor, has neuroprotective effects. This study investigated the histological changes and functional recovery from spinal cord injury (SCI) associated with VPA treatment in a rat model. METHODS: Locomotor function was assessed according to the Basso-Beattie-Bresnahan scale for 2 weeks in rats after receiving twice daily intraperitoneal injections of 200 mg/kg VPA or the equivalent volume of normal saline for 7 days following SCI. The injured spinal cord was then examined histologically, including quantification of cavitation. RESULTS: Basso-Beattie-Bresnahan scale scores in rats receiving VPA were significantly higher than in the saline group (p<0.05). The cavity volume in the VPA group was significantly reduced compared with the control (saline-injected) group (p<0.05). The level of histone acetylation recovered in the VPA group, while it was significantly decreased in the control rats (p<0.05). The macrophage level was significantly decreased in the VPA group (p<0.05). CONCLUSION: VPA influences the restoration of hyperacetylation and reduction of the inflammatory reaction resulting from SCI, and is effective for histology and motor function recovery.

The Neuroprotective Effect of Treatment of Valproic Acid in Acute Spinal Cord Injury

OBJECTIVE: Valproic acid (VPA), as known as histone deacetylase inhibitor, has neuroprotective effects. This study investigated the histological changes and functional recovery from spinal cord injury (SCI) associated with VPA treatment in a rat model. METHODS: Locomotor function was assessed according to the Basso-Beattie-Bresnahan scale for 2 weeks in rats after receiving twice daily intraperitoneal injections of 200 mg/kg VPA or the equivalent volume of normal saline for 7 days following SCI. The injured spinal cord was then examined histologically, including quantification of cavitation. RESULTS: Basso-Beattie-Bresnahan scale scores in rats receiving VPA were significantly higher than in the saline group (p<0.05). The cavity volume in the VPA group was significantly reduced compared with the control (saline-injected) group (p<0.05). The level of histone acetylation recovered in the VPA group, while it was significantly decreased in the control rats (p<0.05). The macrophage level was significantly decreased in the VPA group (p<0.05). CONCLUSION: VPA influences the restoration of hyperacetylation and reduction of the inflammatory reaction resulting from SCI, and is effective for histology and motor function recovery.