Publications by authors named "Haoyu Ye"

72 Publications

Discovery of a Series of Hydroxamic Acid-Based Microtubule Destabilizing Agents with Potent Antitumor Activity.

J Med Chem 2021 10 14;64(20):15379-15401. Epub 2021 Oct 14.

State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital of Sichuan University, Chengdu 610041, Sichuan, China.

Hydroxamic acid group is one of the characteristic pharmacophores of histone deacetylase (HDAC) inhibitors. But here, we discovered a series of hydroxamic acid-based microtubule destabilizing agents (MDAs), which were derived from shortening the length of the linker in HDAC6 inhibitor SKLB-23bb. Interestingly, the low nanomolar antiproliferative activity of these MDAs depended on the presence of hydroxamic acid groups, but their inhibitory effects on HDAC were lost. Among them, showed favorable metabolism stability, high bioavailability, and potent antitumor activity in multidrug-resistant cell lines and A2780/T xenograft model. More importantly, in the patient-derived xenograft models of triple-negative breast cancer and osimertinib-resistant non-small-cell lung cancer, both 20 mg/kg oral and 10 mg/kg intravenous administration of could induce more than 70% tumor inhibition without obvious toxicity. Overall, we discovered that , as a novel MDA based on hydroxamic acid, could serve as a potential MDA for further investigation.
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http://dx.doi.org/10.1021/acs.jmedchem.1c01451DOI Listing
October 2021

Cevipabulin-tubulin complex reveals a novel agent binding site on α-tubulin with tubulin degradation effect.

Sci Adv 2021 May 19;7(21). Epub 2021 May 19.

Laboratory of Natural and Targeted Small Molecule Drugs, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu 610041, China.

Microtubules, composed of αβ-tubulin heterodimers, have remained popular anticancer targets for decades. Six known binding sites on tubulin dimers have been identified thus far, with five sites on β-tubulin and only one site on α-tubulin, hinting that compounds binding to α-tubulin are less well characterized. Cevipabulin, a microtubule-active antitumor clinical candidate, is widely accepted as a microtubule-stabilizing agent by binding to the vinblastine site. Our x-ray crystallography study reveals that, in addition to binding to the vinblastine site, cevipabulin also binds to a new site on α-tubulin. We find that cevipabulin at this site pushes the αT5 loop outward, making the nonexchangeable GTP exchangeable, which reduces the stability of tubulin, leading to its destabilization and degradation. Our results confirm the existence of a new agent binding site on α-tubulin and shed light on the development of tubulin degraders as a new generation of antimicrotubule drugs targeting this novel site.
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http://dx.doi.org/10.1126/sciadv.abg4168DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8133757PMC
May 2021

Cleavage of the N≡N Triple Bond and Unpredicted Formation of the Cyclic 1,3-Diaza-2,4-Diborete (FB) N from N and Fluoroborylene BF.

Angew Chem Int Ed Engl 2021 Jul 26;60(31):17205-17210. Epub 2021 Jun 26.

Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin, Fabeckstrasse 34-36, 14195, Berlin, Germany.

A complete cleavage of the triple bond of N by fluoroborylene (:BF) was achieved in a low-temperature N matrix by the formation of the four-membered heterocycle FB(μ-N) BF, which lacks a trans-annular N-N bond. Additionally, the linear complex FB=N-N=BF and cyclic FB(η -N ) were formed. These novel species were characterized by their matrix infrared spectra and quantum-chemical calculations. The puckered four-membered-ring B N complex shows a delocalized aromatic two-electron π-system in conjugation with the exo-cyclic fluorine π lone pairs. This work may contribute to a rational design of catalysts based on borylene for artificial dinitrogen activation.
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http://dx.doi.org/10.1002/anie.202106984DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8361949PMC
July 2021

Design, Synthesis, and Bioactivity Evaluation of Dual-Target Inhibitors of Tubulin and Src Kinase Guided by Crystal Structure.

J Med Chem 2021 06 3;64(12):8127-8141. Epub 2021 Jun 3.

State Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital of Sichuan University, Chengdu 610041, China.

Klisyri (KX01) is a dual tubulin/Src protein inhibitor that has shown potential therapeutic effects in several tumor models. However, a phase II clinical trial in patients with bone-metastatic castration-resistant prostate cancer was halted because of lack of efficacy. We previously reported that KX01 binds to the colchicine site of β-tubulin and its morpholine group lies close to α-tubulin's surface. Thus, we hypothesized that enhancing the interaction of KX01 with α-tubulin could increase tubulin inhibition and synthesized a series of KX01 derivatives directed by docking studies. Among these derivatives, exhibited more than 10-fold antiproliferation activity in several tumor cells than KX01 and significantly improved antitumor effects. The X-ray crystal structure suggested that both bound to the colchicine site and extended into the interior of α-tubulin to form potent interactions, presenting a novel binding mode. A potential clinical candidate for cancer therapy was identified in this study.
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http://dx.doi.org/10.1021/acs.jmedchem.0c01961DOI Listing
June 2021

Studies on the anti-psoriasis effects and its mechanism of a dual JAK2/FLT3 inhibitor flonoltinib maleate.

Biomed Pharmacother 2021 May 24;137:111373. Epub 2021 Feb 24.

State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China. Electronic address:

Psoriasis is a chronic, inflammatory autoimmune disease mediated by T cells, and characterized with abnormal proliferation and differentiation of keratinocytes, and inflammatory infiltration. The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway has been identified to play essential roles in mediating various of biological processes, and is closely related to autoimmune diseases. Dendritic cells (DCs) are important antigen presenting cells and play an important regulatory role in T cells. The proliferation, differentiation and function of DCs are regulated by JAK and FMS-like tyrosine kinase 3 (FLT3) signal pathways. Flonoltinib maleate (FM), a high selectivity dual JAK2/FLT3 inhibitor with IC values of 0.8 nM and 15 nM for JAK2 and FLT3, respectively, was developed by our laboratory. Moreover, FM was a potent JAK2 inhibitor with 863-fold and 696-fold selectivity over JAK1 and JAK3, respectively. In this study, the anti-psoriasis activity of FM was evaluated both in vitro and in vivo. FM effectively inhibited the proliferation of HaCaT, the inflammatory keratinocyte induced by M5 and markedly suppressed the generation and differentiation of DCs from bone marrow (BM), and inhibited the expression of FLT3 in DCs in vitro. FM effectively inhibited the ear thickening and improved the pathological changes of the ear in interleukin (IL)-23-induced psoriasis-like acanthosis mouse model. Further in keratin 14-vascular endothelial growth factor (K14-VEGF) transgenic homozygous mice model, FM could obviously improve the psoriatic symptom and pathological changes, significantly inhibit the generations of Th1 and Th17 cells in the spleen, and the accumulations of DCs in the ears. FM could also significantly reduce the expression of various inflammatory factors both in C57BL/6 and K14-VEGF mice ears, and the serum of K14-VEGF mice. Mechanism revealed that FM effectively suppressed the phosphorylation of JAK2, STAT3 and STAT5 in inflammatory keratinocytes and the mice ears of C57BL/6 and K14-VEGF, as well as the phosphorylation of FLT3 in K14-VEGF mice ears. In conclusion, FM plays an excellent anti-psoriasis activity, including inhibiting keratinocyte proliferation and regulating inflammatory response through inhibiting JAK2 and FLT3 signaling pathway.
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http://dx.doi.org/10.1016/j.biopha.2021.111373DOI Listing
May 2021

Biphenyl-type neolignans from stem bark of Magnolia officinalis with potential anti-tumor activity.

Fitoterapia 2020 Nov 2;147:104769. Epub 2020 Nov 2.

The Ministry of Education Key Laboratory of Standardization of Chinese Herbal Medicine, State Key Laboratory, Breeding Base of Systematic Research Development and Utilization of Chinese Medicine Resources, School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, People's Republic of China; Laboratory of Natural Product Drugs, State Key Laboratory of Biotherapy and Cancer Center, West China Medical School, West China Hospital, Sichuan University, Chengdu 610041, People's Republic of China.

Six new biphenyl-type neolignans (1-6), and eighteen known compounds (7-24) were isolated from the EtOH extract of Magnolia officinalis. Their structures were determined by 1D and 2D NMR, and by HRMS. The anti-tumor activities of the isolated compounds were evaluated on HepG2, HCT-116, H1975 and HUVEC cell lines. Among the isolated compounds, nine compounds (3, 5, 7, 8, 12, 14, 20, 22, and 24) showed moderate cytotoxicities, and compound 23 showed the best cytotoxicity with IC value lower than 10 μM.
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http://dx.doi.org/10.1016/j.fitote.2020.104769DOI Listing
November 2020

An isoflavone derivative potently inhibits the angiogenesis and progression of triple-negative breast cancer by targeting the MTA2/SerRS/VEGFA pathway.

Cancer Biol Med 2020 08;17(3):693-706

School of Medicine, Nankai University, Tianjin 300071, China.

Angiogenesis plays a vital role in tumor growth and metastasis. Here, we aimed to find novel efficient antiangiogenic molecules targeting vascular endothelial growth factor A (VEGFA ) at the transcriptional level to treat triple-negative breast cancer (TNBC). We used a cell-based seryl tRNA synthetase (SerRS) promoter-driven dual-luciferase reporter system to screen an in-house library of 384 naturally occurring small molecules and their derivatives to find candidate molecules that could upregulate the expression of SerRS, a potent transcriptional repressor of VEGFA. The levels of SerRS and VEGFA were examined by quantitative RT-PCR (qRT-PCR), western blotting, and/or ELISAs in TNBC cells after candidate molecule administration. Zebrafish, the Matrigel plug angiogenesis assay in mice, the TNBC allograft, and xenograft mouse models were used to evaluate the anti-angiogenic and anti-cancer activities. Furthermore, the potential direct targets of the candidates were identified by proteomics and biochemical studies. We found the most active compound was 3-(4-methoxyphenyl) quinolin-4(1H)-one (MEQ), an isoflavone derivative. In TNBC cells, MEQ treatment resulted in increased SerRS mRNA ( < 0.001) and protein levels and downregulated VEGFA production. Both the vascular development of zebrafish and Matrigel plug angiogenesis in mice were inhibited by MEQ. MEQ also suppressed the angiogenesis in TNBC allografts and xenografts in mice, resulting in inhibited tumor growth and prolonged overall survival ( < 0.05). Finally, we found that MEQ regulated SerRS transcription by interacting with MTA2 (Metastasis Associated 1 Family Member 2). Our findings suggested that the MTA2/SerRS/VEGFA axis is a drug-treatable anti-angiogenic target, and MEQ is a promising anti-tumor molecule that merits further investigation for clinical applications.
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http://dx.doi.org/10.20892/j.issn.2095-3941.2020.0010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7476100PMC
August 2020

Correction: Non-toxic dose of liposomal honokiol suppresses metastasis of hepatocellular carcinoma through destabilizing EGFR and inhibiting the downstream pathways.

Oncotarget 2020 Sep 1;11(35):3350-3351. Epub 2020 Sep 1.

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, P.R. China.

[This corrects the article DOI: 10.18632/oncotarget.13687.].
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http://dx.doi.org/10.18632/oncotarget.27369DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7476731PMC
September 2020

FBMF (M = V, Nb, and Ta) and FBMF (M = Nb and Ta): A Combined Matrix Isolation Infrared Spectroscopic and Quantum Chemical Investigation.

J Phys Chem A 2020 Oct 24;124(40):8192-8200. Epub 2020 Sep 24.

School of Chemical Science and Engineering, Shanghai Key Lab of Chemical Assessment and Sustainability, Tongji University, Shanghai 200092, China.

Through matrix isolation infrared spectrometry and quantum chemical calculations, the reactions of laser ablated V, Nb, and Ta with boron trifluoride were investigated in excess solid neon at 4 K. The possible reaction products FBMF, FBMF, and BMF (M = V, Nb, and Ta) were calculated at the B3LYP, BPW91, and CCSD(T) levels of theory. The B-M bond strength in FBMF molecules is confirmed by energy decomposition analysis-natural orbitals for chemical valence calculations, CASSCF calculation, and natural bond orbital analysis, which favors one σ bond and two half π bonds.
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http://dx.doi.org/10.1021/acs.jpca.0c05132DOI Listing
October 2020

Ethanol extract of Liriodendron chinense (Hemsl.) Sarg barks attenuates hyperuricemic nephropathy by inhibiting renal fibrosis and inflammation in mice.

J Ethnopharmacol 2021 Jan 22;264:113278. Epub 2020 Aug 22.

Division of Nephrology and National Clinical Research Center for Geriatrics, Kidney Research Institute, West China Hospital of Sichuan University, Chengdu, 610041, China. Electronic address:

Ethnopharmacological Relevance: Liriodendron chinense (Hemsl.) Sarg, known as the Chinese tulip tree, has a long history of cultivation and utilization in many Asia countries, especially in China to use in traditional Chinese medicine for expelling "wind and dampness", a term corresponding to rheumatic fever and rheumatoid arthritis. Interestingly, the barks of Liriodendron chinense (Hemsl.) Sarg was also found in folk to treat gout. However, further experimental studies remained to confirm its uric acid-lowering effects.

Aim Of The Study: The aim of the study was to evaluate the protective effect of ethanol extract of the barks of Liriodendron chinense (Hemsl.) Sarg (EELC) in a mouse model of hyperuricemic nephropathy (HN) and the involved mechanisms.

Materials And Methods: EELC at a respective dose of 250 mg/kg/d or 500 mg/kg/d were orally administered to HN mice induced by a mixture of adenine (160 mg/kg/d)/potassium oxonate (2.4 g/kg/d) for 21 days. At the end of the treatment, serum uric acid, kidney functions (serum creatinine, blood urea nitrogen and urine microalbumin), 24-h urine uric acid excretion, as well as kidney pathological changes were investigated by biochemical assay, histopathological score, immunofluorescence and histochemistry, RT-qPCR, and western blotting analysis.

Results And Discussion: Oral administration of EELC significantly lowered serum uric acid level at 500 mg/kg (185.75 ± 15.49 μmol/L of EELC vs. 238.28 ± 20.97 μmol/L of HN model, p < 0.01) in HN mice. EELC at 500 mg/kg also remarkably reduced the levels of serum creatinine (82.92 ± 7.86 μmol/L of EELC vs. 92.08 ± 6.13 μmol/L of HN model, p < 0.0001), blood urea nitrogen (21.50 ± 1.87 mmol/L of EELC vs. 29.40 ± 3.95 mmol/L of HN model, p < 0.001) and urine microalbumin (4.25 ± 0.40 mg/L of EELC vs. 5.95 ± 0.33 mg/L of HN model, p < 0.001) to improve renal function. It also attenuated renal fibrosis, especially the high-dose of EELC. Furthermore, EELC could inhibit the activation of NF-κB, ASK1/JNK/c-Jun, JAK2/STAT3 signaling pathways and reduce the release of pro-inflammatory cytokine TNF-α in the kidneys of HN mice. Additionally, EELC remarkably increased urine uric acid excretion of HN mice, which may be achieved by the upregulation of organic anion transporter 1 (OAT1), OAT3 and ATP-binding cassette subfamily G member 2 (ABCG2) proteins.

Conclusions: EELC alleviated the progression of HN by suppressing the activation of NF-κB, ASK1/JNK/c-Jun and JAK2/STAT3 signaling pathway, reducing the infiltration of inflammatory factors and uric acid accumulation in the kidney.
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http://dx.doi.org/10.1016/j.jep.2020.113278DOI Listing
January 2021

Herb-sourced emodin inhibits angiogenesis of breast cancer by targeting VEGFA transcription.

Theranostics 2020 22;10(15):6839-6853. Epub 2020 May 22.

School of Medicine, Nankai University, Tianjin 300071, China.

Anti-angiogenesis is an important and promising strategy in cancer therapy. However, the current methods using anti-vascular endothelial growth factor A (VEGFA) antibodies or inhibitors targeting VEGFA receptors are not as efficient as expected partly due to their low efficiencies in blocking VEGFA signaling . Until now, there is still no method to effectively block VEGFA production in cancer cells from the very beginning, i.e., from the transcriptional level. Here, we aimed to find bioactive small molecules to block VEGFA transcription. We screened our natural compound pool containing 330 small molecules derived from Chinese traditional herbs for small molecules activating the expression of seryl-tRNA synthetase (SerRS), which is a newly identified potent transcriptional repressor of VEGFA, by a cell-based screening system in MDA-MB-231 cell line. The activities of the candidate molecules on regulating SerRS and VEGFA expression were first tested in breast cancer cells. We next investigated the antiangiogenic activity by testing the effects of candidate drugs on the vascular development in zebrafish and by matrigel plug angiogenesis assay in mice. We further examined the antitumor activities of candidate drugs in two triple-negative breast cancer (TNBC)-bearing mouse models. Furthermore, streptavidin-biotin affinity pull-down assay, coimmunoprecipitation assays, docking analysis and chromatin immunoprecipitation were performed to identify the direct targets of candidate drugs. We identified emodin that could greatly increase SerRS expression in TNBC cells, consequently reducing VEGFA transcription. Emodin potently inhibited vascular development of zebrafish and blocked tumor angiogenesis in TNBC-bearing mice, greatly improving the survival. We also identified nuclear receptor corepressor 2 (NCOR2) to be the direct target of emodin. Once bound by emodin, NCOR2 got released from SerRS promoter, resulting in the activation of SerRS expression and eventually the suppression of VEGFA transcription. We discovered a herb-sourced small molecule emodin with the potential for the therapy of TNBC by targeting transcriptional regulators NCOR2 and SerRS to suppress VEGFA transcription and tumor angiogenesis.
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http://dx.doi.org/10.7150/thno.43622DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7295066PMC
May 2021

Identification and optimization of piperine analogues as neuroprotective agents for the treatment of Parkinson's disease via the activation of Nrf2/keap1 pathway.

Eur J Med Chem 2020 Aug 5;199:112385. Epub 2020 May 5.

State Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital of Sichuan University, Chengdu, 610041, China. Electronic address:

Parkinson's disease (PD) is a slowly progressive and complex neurodegenerative disorder. Up to date, there are no approved drugs that could slow or reverse the neurodegenerative process of PD. Here, we reported the synthesis of series of piperine analogues and the evaluation of their neuroprotective effects against hydrogen peroxide (HO) induced damage in the neuron-like PC12 cells. Among these analogues, 3b exhibited the most potent protection effect and its underlying mechanism was further investigated. Further results indicated that the ROS scavenging and cytoprotection effect of 3b might be related to the Nrf2 activation and upregulation of related phase II antioxidant enzymes, such as HO-1 and NQO1. In in vivo study, oral administration (100 mg/kg) of 3b significantly attenuated PD-associated behavioral deficits in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD and protected tyrosine hydroxylase-immunopositive dopaminergic neurons. Our results provided evidence that 3b might be a promising candidate for Parkinson's disease treatment.
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http://dx.doi.org/10.1016/j.ejmech.2020.112385DOI Listing
August 2020

Design, synthesis and discovery of 2(1H)-quinolone derivatives for the treatment of pulmonary fibrosis through inhibition of TGF-β/smad dependent and independent pathway.

Eur J Med Chem 2020 Jul 6;197:112259. Epub 2020 Apr 6.

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, 610041, PR China. Electronic address:

Idiopathic pulmonary fibrosis (IPF) is a progressive, life-threatening and interstitial lung disease with the median survival of only 3-5 years. However, due to the unclear etiology and problems in accurate diagnosis, up to now only two drugs were approved by FDA for the treatment of IPF and their outcome responses are limited. Numerous studies have shown that TGF-β is the most important cytokine in the development of pulmonary fibrosis and plays a role through its downstream signaling molecule TGF-binding receptor Smads protein. In this paper, compounds bearing 2(1H)-quinolone scaffold were designed and their anti-fibrosis effects were evaluated. Of these compounds, 20f was identified as the most active one and could inhibit TGF-β-induced collagen deposition of NRK-49F cells and mouse fibroblasts migration with comparable activity and lower cytotoxicity than nintedanib in vitro. Further mechanism studies indicated that 20f reduced the expression of fibrogenic phenotypic protein α-SMA and collagen Ⅰ by inhibiting the TGF-β/Smad dependent pathways and ERK1/2 and p38 pathways. Moreover, compared with the nintedanib, 20f (100 mg/kg/day, p.o) more effectively alleviated collagen deposition in lung tissue and delayed the destruction of lung tissue structure both in bleomycin-induced prevention and treatment mice pulmonary fibrosis models. The immunohistochemical experiments further showed that 20f could block the expression level of phosphorylated Smad3 in the lung tissue cells, which resulted in its anti-fibrosis effects in vivo. In addition, 20f demonstrated good bioavailability (F = 41.55% vs 12%, compare with nintedanib) and an appropriate elimination half-life (T = 3.5 h), suggesting that 20f may be a potential drug candidate for the treatment of pulmonary fibrosis.
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http://dx.doi.org/10.1016/j.ejmech.2020.112259DOI Listing
July 2020

Author Correction: Isogambogenic acid induces apoptosis-independent autophagic cell death in human non-small-cell lung carcinoma cells.

Sci Rep 2020 Apr 20;10(1):6895. Epub 2020 Apr 20.

State Key Laboratory of Biotherapy/Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital of Sichuan University, Chengdu, China.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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http://dx.doi.org/10.1038/s41598-020-62992-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7170920PMC
April 2020

Alkaloids from Black Pepper ( L.) Exhibit Anti-Inflammatory Activity in Murine Macrophages by Inhibiting Activation of NF-κB Pathway.

J Agric Food Chem 2020 Feb 18;68(8):2406-2417. Epub 2020 Feb 18.

Laboratory of Natural Product Drugs, Cancer Center, West China Medical School, West China Hospital , Sichuan University , Chengdu 610041 , People's Republic of China.

Black pepper ( L.) has been commonly utilized in food preparation and traditional medicine in several countries. Seven new amide alkaloids, pipernigramides A-G (, , , and -), a new piperic ester, pipernigrester A (), along with 47 known compounds were isolated from the EtOH extract of . The inhibitory effects on nitric oxide (NO) of all compounds were then evaluated. Among the tested compounds, three of them (-) significantly inhibited inducible nitric oxide synthase (iNOS)-mediated NO (IC = 4.74 ± 0.18, 4.08 ± 0.19, and 3.71 ± 0.32 μM, respectively), and IL-1β, IL-6, TNF-α, and PGE release in RAW 264.7 cells stimulated by lipopolysaccharide. Moreover, - suppressed IκB degradation and further inhibited the cytosol-nucleus translocation of the p65 subunit by targeting IKK-β. In the carrageenan-induced paw edema test, - demonstrated anti-inflammatory effects as well. These results indicate that all three compounds from have the potential anti-inflammatory effects.
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http://dx.doi.org/10.1021/acs.jafc.9b07754DOI Listing
February 2020

Synthesis and discovery of new compounds bearing coumarin scaffold for the treatment of pulmonary fibrosis.

Eur J Med Chem 2020 Jan 19;185:111790. Epub 2019 Oct 19.

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center, Chengdu, 610041, China. Electronic address:

Idiopathic pulmonary fibrosis, characterized by excess accumulation of extracellular matrix, involved in many chronic diseases or injuries, threatens human health greatly. We have reported a series of compounds bearing coumarin scaffold which potently inhibited TGF-β-induced total collagen accumulation in NRK-49F cell line and migration of macrophages. Compound 9d also suppressed the TGF-β-induced protein expression of COL1A1, α-SMA, and p-Smad3 in vitro. Meanwhile, 9d at a dose of 100 mg/kg/day through oral administrations for 4 weeks effectively alleviated infiltration of inflammatory cells in lung tissue and fibrotic degree in bleomycin-induced pulmonary fibrosis model, which may related to its inhibition of TGF-β/Smad3 pathway and anti-inflammation efficacy. In addition, 9d demonstrated decent bioavailability (F = 39.88%) and suitable eliminated half-life time (T = 13.09 h), suggesting that 9d could be a potential drug candidate for the treatment of fibrotic diseases.
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http://dx.doi.org/10.1016/j.ejmech.2019.111790DOI Listing
January 2020

Reversible binding of the anticancer drug KXO1 (tirbanibulin) to the colchicine-binding site of β-tubulin explains KXO1's low clinical toxicity.

J Biol Chem 2019 11 18;294(48):18099-18108. Epub 2019 Oct 18.

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy and Cancer, Chengdu 610041, China. Electronic address:

KXO1 (tirbanibulin or KX2-391) is as a non-ATP-competitive inhibitor of SRC proto-oncogene nonreceptor tyrosine kinase (SRC) and is being clinically investigated for the management of various cancers and actinic keratosis. Recently, KXO1 has also been shown to strongly inhibit tubulin. Interestingly, unlike conventional tubulin-targeting drugs, KXO1 has exhibited low toxicity in preclinical and clinical studies, but the reason for this remains elusive, as are the KXO1-binding site and other details of the interaction of KXO1 with tubulin. Here, cell-based experiments revealed that KXO1 induces tubulin depolymerization and G/M phase cell cycle arrest at low nanomolar concentrations, similar to colchicine, used as a positive control. Results from biochemical experiments, including an ,-ethylenebis(iodoacetamide) competition assay, disclosed that KXO1 binds to the colchicine-binding site on β-tubulin, further confirmed by the crystal structure of the tubulin-KXO1 complex at 2.5-Å resolution. A high-quality electron density map of the crystallographic data enabled us to unambiguously determine the position and orientation of KXO1 in the colchicine-binding site, revealing the detailed interactions between KXO1 and tubulin. We also found that KXO1 binds reversibly to purified tubulin, induces a totally reversible cellular effect (G/M cell cycle arrest), and possesses no cellular toxicity 5 days after drug washout, explaining KXO1's low toxicity. In summary, we show that KXO1 binds to the colchicine-binding site of tubulin and resolved the crystal structure of the tubulin-KXO1 complex. Importantly, KXO1's reversible binding to tubulin explains its clinically low toxicity, an insight that could guide further clinical applications of KXO1.
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http://dx.doi.org/10.1074/jbc.RA119.010732DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6885616PMC
November 2019

The Natural Compound Withaferin A Covalently Binds to Cys239 of -Tubulin to Promote Tubulin Degradation.

Mol Pharmacol 2019 12 4;96(6):711-719. Epub 2019 Oct 4.

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital of Sichuan University and Collaborative Innovation Center of Biotherapy and Cancer, Chengdu, People's Republic of China

Withaferin A (WIT) is a natural product possessing a wide range of pharmacologic activities. Previous studies have reported covalent binding of WIT to tubulin and down-of tubulin protein levels although the underlying mechanisms remain to be established. In the current investigation, we showed that WIT induces down-regulation of tubulin in a post-transcriptional manner, suggestive of direct and potent activity in tubulin degradation. The ,'-ethylene bis(iodoacetamide) assay and competitive binding experiments with four colchicine site-targeted tubulin inhibitors further revealed that WIT interacts with the colchicine site of tubulin to promote degradation. WIT irreversibly inhibited tubulin polymerization, and mass spectrometry results disclosed binding to cysteine at position 239 (Cys239) and Cys303 sites of -tubulin. Interestingly, WIT promoted degradation of the -tubulin isoforms containing Cys239 [2, 4, and 5()] but had no effect on those containing Ser239 (3 and 6). Moreover, a C239S but not C303S mutation in -tubulin completely abolished the degradation effect of WIT, suggesting that the Cys239-WIT covalent bond accounts for this activity. Our collective results clearly demonstrate that covalent interactions between WIT and Cys239 of -tubulin promote tubulin degradation, supporting its potential utility as a therapeutic compound. SIGNIFICANCE STATEMENT: Withaferin A, a natural product possessing a wide range of pharmacologic activities, covalently binds to Cys239 of -tubulin near the colchicine site, and the WIT-Cys239 covalent bond accounts for WIT-induced tubulin degradation, fully clarifying the underlying mechanisms and supporting its potential utility a therapeutic compound.
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http://dx.doi.org/10.1124/mol.119.117812DOI Listing
December 2019

Purinostat Mesylate Is a Uniquely Potent and Selective Inhibitor of HDACs for the Treatment of -Induced B-Cell Acute Lymphoblastic Leukemia.

Clin Cancer Res 2019 12 22;25(24):7527-7539. Epub 2019 Aug 22.

State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital of Sichuan University, Chengdu, China.

Purpose: This study was to perform preclinical evaluation of a novel class I and IIb HDAC-selective inhibitor, purinostat mesylate, for the treatment of Ph B-cell acute lymphoblastic leukemia (B-ALL).

Experimental Design: Biochemical assays were used to test enzymatic activity inhibition of purinostat mesylate. Ph leukemic cell lines and patient cells were used to evaluate purinostat mesylate activity . BL-2 secondary transplantation Ph B-ALL mouse model was used to validate its efficacy, mechanism, and pharmacokinetics properties . -induced primary B-ALL mouse model and PDX mouse model derived from relapsed Ph B-ALL patient post TKI treatment were used to determine the antitumor effect of purinostat mesylate for refractory or relapsed Ph B-ALL. Long-term toxicity and hERG blockade assays were used to safety evaluation of purinostat mesylate.

Results: Purinostat mesylate, a class I and IIb HDAC highly selective inhibitor, exhibited robust antitumor activity in hematologic cancers. Purinostat mesylate at low nanomolar concentration induced apoptosis, and downregulated BCR-ABL and c-MYC expression in Ph leukemia cell lines and primary Ph B-ALL cells from relapsed patients. Purinostat mesylate efficiently attenuated Ph B-ALL progression and significantly prolonged the survival both in BL-2 secondary transplantation model with clinical patient symptoms of Ph B-ALL, -induced primary B-ALL mouse model, and PDX model derived from patients with relapsed Ph B-ALL post TKI treatment. In addition, purinostat mesylate possesses favorable pharmacokinetics and low toxicity properties.

Conclusions: Purinostat mesylate provides a new therapeutic strategy for patients with Ph B-ALL, including those who relapse after TKI treatment.
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http://dx.doi.org/10.1158/1078-0432.CCR-19-0516DOI Listing
December 2019

Flavonoids from the stems of Drake mediate cytotoxic activity through apoptosis and autophagy in cancer cells.

J Adv Res 2019 Nov 21;20:117-127. Epub 2019 Jun 21.

Lab of Natural Product Drugs and Cancer Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu 610041, People's Republic of China.

In this study, systematic separation and subsequent pharmacological activity studies were carried out to identify cytotoxic natural products from the dried stems of Drake. Five previously undescribed isoflavones, pachyvones A-E; one previously undescribed xanthone, pachythone A; and twenty-two known compounds were obtained. The structures of these compounds were assigned on the basis of 1D/2D NMR data and high-resolution electrospray ionization mass spectroscopy analysis. Preliminary activity screening with HeLa and MCF-7 cells showed that ten compounds (-, , , -, , and ) had potential cytotoxicity. Further in-depth activity studies with five cancer cell lines (HeLa, HepG2, MCF-7, Hct116, and MDA-MB-231) and one normal cell line (HUVEC) revealed that these ten compounds showed specific cytotoxicity in cancer cells, with IC values ranging from 5 to 40 μM, while they had no effect on normal cell lines. To investigate whether the cytotoxicity of these ten compounds was associated with autophagy, their autophagic effects were evaluated in GFP-LC3-HeLa cells. The results demonstrated that compound (durmillone) significantly induced autophagy in a concentration-dependent manner and had the best activity as an autophagy inducer among all of the compounds. Therefore, compound was selected for further study. The PI/Annexin V double staining assay and Western blotting results revealed that compound also induced obvious apoptosis in HeLa and MCF-7 cells, which suggests that it mediates cytotoxic activity through activation of both apoptosis and autophagy. Taken together, this study identified ten natural cytotoxic products from the dried stems of Drake, of which compound induced apoptosis and autophagy and could be an anticancer drug candidate.
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http://dx.doi.org/10.1016/j.jare.2019.06.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6626068PMC
November 2019

PEG-derivatized birinapant as a nanomicellar carrier of paclitaxel delivery for cancer therapy.

Colloids Surf B Biointerfaces 2019 Oct 13;182:110356. Epub 2019 Jul 13.

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Collaborative Innovation Center for Biotherapy, Chengdu, 610041, PR China. Electronic address:

A novel triblock amphiphilic copolymer (PAL-PEG-Birinapant) was designed and synthesized as a dual-functional micellar carrier utilizing birinapant (an inhibitor of inhibitor-of-apoptosis proteins) as a pH-sensitive segment and inhibitor-of-apoptosis proteins-targeting ligand. The mixed micelles comprised of PAL-PEG-Birinapant (PPB) and mPEG2k-PDLLA2k (MPP), named as PPB/MPP (2/1,w/w) micelles were developed for enhanced solubility and antitumor potency of hydrophobic drugs as paclitaxel (PTX). In vitro cell viability and cytotoxicity studies revealed that the PTX-loaded PPB/MPP micelles were more potent than the commercial PTX formulation (Taxol), as well as the in vitro cell apoptosis study. Clear differences in the intracellular uptake of free coumarin-6 (C6) solution and C6-loaded PPB/MPP micelles were observed and indicated that the PPB/MPP micelles could efficiently deliver chemical compound into tumor cells. PPB copolymer and PTX-loaded PPB/MPP micelles demonstrated an excellent safety profile with a maximum tolerated dose (MTD) of above 1.2 g copolymer/kg and above 100 mg PTX/kg in mice respectively in contrast to 20˜24 mg/kg of Taxol®. The near infrared (NIR) fluorescence imaging showed that PPB/MPP micelles persisted for a relatively long time in the circulation and accumulated preferentially in tumor tissue. Moreover, PTX loaded PPB/MPP micelles significantly inhibited the tumor growth both in MDA-MB-231 and Ramos cancer xenograft mice models without obvious toxicity. Collectively, our study presents a new dual-functional micelles that improve the therapeutic efficacy of PTX in vitro and in vivo.
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http://dx.doi.org/10.1016/j.colsurfb.2019.110356DOI Listing
October 2019

Covalent modification of Cys-239 in β-tubulin by small molecules as a strategy to promote tubulin heterodimer degradation.

J Biol Chem 2019 05 2;294(20):8161-8170. Epub 2019 Apr 2.

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China. Electronic address:

Clinical microtubule-targeting drugs are functionally divided into microtubule-destabilizing and microtubule-stabilizing agents. Drugs from both classes achieve microtubule inhibition by binding different sites on tubulin and inhibiting or promoting polymerization with no concomitant effects on the protein levels of tubulin heterodimers. Here, we have identified a series of small molecules with diverse structures potentially representing a third class of novel tubulin inhibitors that promote degradation by covalent binding to Cys-239 of β-tubulin. The small molecules highlighted in this study include T0070907 (a peroxisome proliferator-activated receptor γ inhibitor), T007-1 (a T0070907 derivative), T138067, ,'-ethylene-bis(iodoacetamide) (EBI), and allyl isothiocyanate (AITC). Label-free quantitative proteomic analysis revealed that T007-1 promotes tubulin degradation with high selectivity. Mass spectrometry findings showed covalent binding of both T0070907 and T007-01 to Cys-239 of β-tubulin. Furthermore, T007-1 exerted a degradative effect on tubulin isoforms possessing Cys-239 (β2, β4, and β5(β)) but not those containing Ser-239 (β3, β6) or mutant β-tubulin with a C239S substitution. Three small molecules (T138067, EBI, and AITC) also reported to bind covalently to Cys-239 of β-tubulin similarly induced tubulin degradation. Our results strongly suggest that covalent modification of Cys-239 of β-tubulin by small molecules could serve as a novel strategy to promote tubulin heterodimer degradation. We propose that these small molecules represent a third novel class of tubulin inhibitor agents that exert their effects through degradation activity.
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http://dx.doi.org/10.1074/jbc.RA118.006325DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6527155PMC
May 2019

Identification of Pyrrolo[2,3- d]pyrimidine-Based Derivatives as Potent and Orally Effective Fms-like Tyrosine Receptor Kinase 3 (FLT3) Inhibitors for Treating Acute Myelogenous Leukemia.

J Med Chem 2019 04 15;62(8):4158-4173. Epub 2019 Apr 15.

A series of pyrrolo[2,3- d]pyrimidine derivatives were prepared and optimized for cytotoxic activities against FLT3-ITD mutant cancer cells. Among them, compound 9u possessed nanomolar FLT3 inhibitory activities and subnanomolar inhibitory activities against MV4-11 and Molm-13 cells. It also showed excellent inhibitory activities in FLT3-ITD-D835V and FLT3-ITD-F691L cells which were resistant to quizartinib. Furthermore, 9u exhibited over 40-fold selectivity toward FLT3 relative to c-Kit kinase, which might reduce myelosuppression toxicity. Cellular assays demonstrated that 9u inhibited phosphorylated FLT3 and downstream signaling factors and also induced cell cycle arrest in the G/G stage and apoptosis in MV4-11 and Molm-13 cells. Oral administration of 9u at 10 mg/kg could achieve rapid tumor extinction in the MV4-11 xenograft model and significantly inhibit the tumor growth in the MOLM-13 xenograft model with a tumor growth inhibitory rate of 96% without obvious toxicity. Additionally, 9u demonstrated high bioavailability ( F = 59.5%) and suitable eliminated half-life time ( T = 2.06 h), suggesting that 9u may be a potent candidate for treating acute myelogenous leukemia.
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http://dx.doi.org/10.1021/acs.jmedchem.9b00223DOI Listing
April 2019

Millepachine showed novel antitumor effects in cisplatin-resistant human ovarian cancer through inhibiting drug efflux function of ATP-binding cassette transporters.

Phytother Res 2018 Dec 19;32(12):2428-2435. Epub 2018 Aug 19.

Department of Thyroid Surgery, West China Hospital, Sichuan University, Chengdu, China.

Millepachine (MIL), a bioactive natural chalcone from Chinese herbal medicine Millettia pachycarpa Benth, exhibits strong antitumor effects against many human cancer cells both in vitro and in vivo. In this study, we found that MIL significantly inhibited the proliferation of cisplatin-resistant A2780CP cells via inducing obvious G2/M arrest and apoptosis and down-regulating the activity of topoisomerase II protein. We further found that the mechanism by which MIL showed good antitumor effects in cisplatin-resistant human ovarian cancer was associated with inhibiting the expression of ATP-binding cassette transporters in cisplatin-resistant A2780CP cells. Importantly, MIL did not only significantly inhibit the tumor growth in cisplatin-sensitive A2780S xenograft model, with an inhibitory rate of 73.21%, but also inhibited the tumor growth in the cisplatin-resistant A2780CP xenograft model, with an inhibitory rate of 65.68% (p < 0.001 vs. control; p < 0.001 vs. DDP). In addition, MIL did not induce acquired drug resistance in A2780S tumor-bearing mice with an inhibitory rate of 60.03%. The promising in vitro and in vivo performance indicated that MIL exhibited potential significance for drug research and development.
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http://dx.doi.org/10.1002/ptr.6180DOI Listing
December 2018

Discovery and synthesis of novel magnolol derivatives with potent anticancer activity in non-small cell lung cancer.

Eur J Med Chem 2018 Aug 27;156:190-205. Epub 2018 Jun 27.

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, PR China; School of Pharmacy, Chengdu University of TCM, The Ministry of Education Key Laboratory of Standardization of Chinese Herbal Medicine, State Key Laboratory Breeding Base of Systematic Research, Development and Utilization of Chinese Medicine Resources, Chengdu, 611137, PR China. Electronic address:

EGFR T790 M accounts for 50% to 60% of cases of non-small-cell lung carcinoma (NSCLC) resistance to the first-generation EGFR tyrosine kinase inhibitors (TKIs). Hence, identifying novel compounds with activity against TKIs resistant is of great value. In this study, twenty honokiol and magnolol derivatives were isolated from the EtOH extract of Magnolia officinalis and the antiproliferative activity was evaluated on HCC827 (19del EGFR mutation), H1975 (L858 R/T790 M EGFR mutation), and H460 (KRAS mutation) cell lines. Among the isolated compounds, piperitylmagnolol (a 3-substituted magnolol derivative) showed the best antiproliferative activity against those three cell lines with the IC values of 15.85, 15.60 and 18.60 μM, respectively, which provided a direction for the structural modification of magnolol. Further structural modification led to the synthesis of thirty-one magnolol derivatives, and compounds A13, C1, and C2 exhibited significant and broad-spectrum antiproliferative activity with the IC values ranging from 4.81 to 13.54 μM, which were approximately 4- and 8-fold more potent than those of honokiol and magnolol, respectively. Moreover, their aqueous solubility was remarkably improved with 12-, 400- and 10 fold greater than those of honokiol and magnolol. Anti-tumor mechanism research revealed that these three compounds were able to induce cell cycle arrest at G0/G1 phase, cause efficient apoptosis in H1975 cells, and also prevent the migration of HUVECs in a dose-dependent manner through Cdk2, Cdk4, Cyclin E, and Cyclin D1 inhibition as well as up-regulation of cleaved-PARP and cleaved-caspase 3 levels. In in vivo antitumor activity, C2 (10, 30 and 100 mg/kg, po) dose-dependently inhibited the tumor growth in H1975 xenograft model with the tumor inhibition rate of 46.3%, 59.3% and 61.2% respectively, suggesting that C2 is a potential oral anticancer agent deserving further investigation.
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http://dx.doi.org/10.1016/j.ejmech.2018.06.048DOI Listing
August 2018

SKLB060 Reversibly Binds to Colchicine Site of Tubulin and Possesses Efficacy in Multidrug-Resistant Cell Lines.

Cell Physiol Biochem 2018 22;47(2):489-504. Epub 2018 May 22.

State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, China.

Background/aims: Many tubulin inhibitors are in clinical use as anti-cancer drugs. In our previous study, a novel series of 4-substituted coumarins derivatives were identified as novel tubulin inhibitors. Here, we report the anti-cancer activity and underlying mechanism of one of the 4-substituted coumarins derivatives (SKLB060).

Methods: The anti-cancer activity of SKLB060 was tested on 13 different cancer cell lines and four xenograft cancer models. Immunofluorescence staining, cell cycle analysis, and tubulin polymerization assay were employed to study the inhibition of tubulin. N, N '-Ethylenebis(iodoacetamide) assay was used to measure binding to the colchicine site. Wound-healing migration and tube formation assays were performed on human umbilical vascular endothelial cells to study anti-vascular activity (the ability to inhibit blood vessel growth). Mitotic block reversibility and structural biology assays were used to investigate the SKLB060-tubulin bound model.

Results: SKLB060 inhibited tubulin polymerization and subsequently induced G2/M cell cycle arrest and apoptosis in cancer cells. SKLB060 bound to the colchicine site of β-tubulin and showed antivascular activity in vitro. Moreover, SKLB060 induced reversible cell cycle arrest and reversible inhibition of tubulin polymerization. A mitotic block reversibility assay showed that the effects of SKLB060 have greater reversibility than those of colcemid (a reversible tubulin inhibitor), indicating that SKLB060 binds to tubulin in a totally reversible manner. The crystal structures of SKLB060-tubulin complexes confirmed that SKLB060 binds to the colchicine site, and the natural coumarin ring in SKLB060 enables reversible binding.

Conclusions: These results reveal that SKLB060 is a powerful and reversible microtubule inhibitor that binds to the colchicine site and is effective in multidrug-resistant cell lines.
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http://dx.doi.org/10.1159/000489983DOI Listing
July 2018

The compound millepachine and its derivatives inhibit tubulin polymerization by irreversibly binding to the colchicine-binding site in β-tubulin.

J Biol Chem 2018 06 24;293(24):9461-9472. Epub 2018 Apr 24.

From the State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu 610041, China and

Inhibitors that bind to the paclitaxel- or vinblastine-binding sites of tubulin have been part of the pharmacopoeia of anticancer therapy for decades. However, tubulin inhibitors that bind to the colchicine-binding site are not used in clinical cancer therapy, because of their low therapeutic index. To address multidrug resistance to many conventional tubulin-binding agents, numerous efforts have attempted to clinically develop inhibitors that bind the colchicine-binding site. Previously, we have found that millepachine (MIL), a natural chalcone-type small molecule extracted from the plant , and its two derivatives (MDs) SKLB028 and SKLB050 have potential antitumor activities both and However, their cellular targets and mechanisms are unclear. Here, biochemical and cellular experiments revealed that the MDs directly and irreversibly bind β-tubulin. X-ray crystallography of the tubulin-MD structures disclosed that the MDs bind at the tubulin intradimer interface and to the same site as colchicine and that their binding mode is similar to that of colchicine. Of note, MDs inhibited tubulin polymerization and caused G/M cell-cycle arrest. Comprehensive analysis further revealed that free MIL exhibits an s- conformation, whereas MIL in the colchicine-binding site in tubulin adopts an s- conformation. Moreover, introducing an α-methyl to MDs to increase the proportion of s- conformations augmented MDs' tubulin inhibition activity. Our study uncovers a new class of chalcone-type tubulin inhibitors that bind the colchicine-binding site in β-tubulin and suggests that the s- conformation of these compounds may make them more active anticancer agents.
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http://dx.doi.org/10.1074/jbc.RA117.001658DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6005456PMC
June 2018

The effect and mechanism of millepachine-disrupted spindle assembly in tumor cells.

Anticancer Drugs 2018 06;29(5):449-456

Department of Thyroid Surgery.

Millepachine (MIL) is a bioactive natural product that shows great potential for cancer treatment. Previous studies showed that MIL was a novel cancer drug candidate with a special structure. To provide reference for the research and development of MIL, we further investigated the mechanism of MIL inducing G2/M arrest and found MIL disrupted spindle assembly in tumor cells. In this study, we investigated the disrupting spindle assembly effects of MIL with a focus on its potential mechanism of action. First, we indicated that MIL did not inhibit microtubule polymerization from the results of in-vivo microtubule nucleation assay and microtubule polymerization in-vitro assay but delayed this process by inhibiting the production of ATP in tumor cells. Thereafter, we investigated the effect of MIL on the mitotic spindle. We found that MIL induced multipolar spindles by inhibiting the activity of Eg5 and inhibited mitotic spindle formation and chromatin condensation by the activation of the spindle assembly checkpoint (SAC) in tumor cells. These results established a novel function of MIL in regulating the assembly of mitotic spindle. As Eg5 and SAC are antitumor targets, effect of MIL on the Eg5 protein and SAC activation hinted that MIL has novel application in the development of antitumor drugs.
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http://dx.doi.org/10.1097/CAD.0000000000000618DOI Listing
June 2018

SKLB-23bb, A HDAC6-Selective Inhibitor, Exhibits Superior and Broad-Spectrum Antitumor Activity via Additionally Targeting Microtubules.

Mol Cancer Ther 2018 04;17(4):763-775

State Key Laboratory of Biotherapy, Collaborative Innovation Center of Biotherapy and Cancer Center, West China Hospital of Sichuan University, Chengdu, China.

Our previous study reported that SKLB-23bb, an orally bioavailable HDAC6-selective inhibitor, exhibited superior antitumor efficiency both and in comparison with ACY1215, a HDAC6-selective inhibitor recently in phase II clinical trial. This study focused on the mechanism related to the activity of SKLB-23bb. We discovered that despite having HDAC6-selective inhibition equal to ACY1215, SKLB-23bb showed cytotoxic effects against a panel of solid and hematologic tumor cell lines at the low submicromolar level. Interestingly, in contrast to the reported HDAC6-selective inhibitors, SKLB-23bb was more efficient against solid tumor cells. Utilizing HDAC6 stably knockout cell lines constructed by CRISPR-Cas9 gene editing, we illustrated that SKLB-23bb could remain cytotoxic independent of HDAC6 status. Investigation of the mechanism confirmed that SKLB-23bb exerted its cytotoxic activity by additionally targeting microtubules. SKLB-23bb could bind to the colchicine site in β-tubulin and act as a microtubule polymerization inhibitor. Consistent with its microtubule-disrupting ability, SKLB-23bb also blocked tumor cell cycle at G-M phase and triggered cellular apoptosis. In solid tumor xenografts, oral administration of SKLB-23bb efficiently inhibited tumor growth. These results suggested that SKLB-23bb was an orally bioavailable HDAC6 and microtubule dual targeting agent. The microtubule targeting profile enhanced the antitumor activity and expanded the antitumor spectrum of SKLB-23bb, thus breaking through the limitation of HDAC6 inhibitors. .
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http://dx.doi.org/10.1158/1535-7163.MCT-17-0332DOI Listing
April 2018

Identification, characterization and HPLC quantification of formulation-related impurities of honokiol, an antitumor natural drug candidate in clinical trials.

J Pharm Biomed Anal 2018 May 21;153:186-192. Epub 2018 Feb 21.

Lab of Natural Product Drugs, Cancer Center, West China Medical School, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.

Natural products and their derivatives have historically been invaluable as a source of therapeutic agents. Honokiol, as a well-known natural product in Chinese herbal medicine Houpu, is finally being studied in a Phase I clinical trial (CTR20170822) in patients with Advanced Non-Small Cell Lung Cancer (NSCLS) in China this year. During the honokiol liposome formulation process, five major impurities were present in the range of 0.05-0.1% based on the HPLC analysis. These five major impurities were obtained from the forced degradation product of honokiol through countercurrent chromatography and prep-HPLC. The structure were elucidated with H NMR, C NMR, 2D NMR and MS spectral data. The proposed HPLC method was validated for specificity, linearity (concentration range 0.01-1.62, 0.003-0.96, 0.05-7.98, 0.04-6.52, 0.03-5.18 μg/ml for impurities I-V respectively, R2 > 0.9988), accuracy (99.11-100.67%), precision (CV < 1.6%), and sensitivity (LOD 3.3, 0.1, 16.7, 13.3, 10.0 ng/ml for impurities I-V respectively). The validated method was employed in the further study of the honokiol drug substance.
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http://dx.doi.org/10.1016/j.jpba.2018.02.033DOI Listing
May 2018
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