Li-Ying Ma

Design, Synthesis, and Structure–Activity Relationship of Novel LSD1 Inhibitors Based on Pyrimidine–Thiourea Hybrids As Potent, Orally Active Antitumor Agents

Histone lysine specific demethylase 1 (LSD1) was reported to be overexpressed in several human cancers and recognized as a promising anticancer drug target. In the current study, we designed and synthesized a novel series of pyrimidine-thiourea hybrids and evaluated their potential LSD1 inhibitory effect. One of the compounds, 6b, containing a terminal alkyne appendage, was shown to be the most potent and selective LSD1 inhibitor in vitro and exhibited strong cytotoxicity against LSD1 overexpressed gastric cancer cells. Compound 6b also showed marked inhibition of cell migration and invasion as well as significant in vivo tumor suppressing and antimetastasis role, without significant side effects by oral administration. Our findings indicate that the pyrimidine-thiourea-based LSD1 inactivator may serve as a leading compound targeting LSD1 overexpressed cancers.

Design and synthesis of novel 1,2,3-triazole-pyrimidine-urea hybrids as potential anticancer agents.

A series of novel 1,2,3-triazole-pyrimidine-urea hybrids were designed, synthesized and evaluated for anticancer activity against four selected cancer cell lines (MGC-803, EC-109, MCF-7 and B16-F10). Majority of the synthesized compounds exhibited moderate to potent activity against all the cancer cell lines assayed. Particularly, compounds 26, 30 and 38 exhibited excellent growth inhibition against B16-F10 with IC50 values of 32nM, 35nM and 42nM, respectively. Flow cytometry analysis demonstrated that compound 26 induced the cellular apoptosis in a concentration-dependent manner.

Synthesis and biological evaluation of novel pyrimidine–benzimidazol hybrids as potential anticancer agents

A series of pyrimidine-benzimidazol hybrids was synthesized and evaluated for anticancer activity on four human cancer cell lines including MCF-7, MGC-803, EC-9706 and SMMC-7721. Some of the synthesized compounds exhibited moderate to potent activity against MGC-803 and MCF-7. Among them, compounds 5a-b and 6a-b showed most effective activity. Compounds 5b and 6b were more cytotoxic than 5-fluorouracil against all tested four human cancer cell lines, with IC50 values ranging from 2.03 to 10.55 μM and 1.06 to 12.89 μM, respectively. Flow cytometry analysis demonstrated that treatment of MGC-803 with 6b led to cell cycle arrest at G2/M phase accompanied by an increase in apoptotic cell death.

Geridonin and paclitaxel act synergistically to inhibit the proliferation of gastric cancer cells through ROS-mediated regulation of the PTEN/PI3K/Akt pathway

Paclitaxel, a taxane, is a cytotoxic chemotherapeutic agent that targets microtubules. It has become a front-line therapy for a broad range of malignancies, including lung, breast, gastric, esophageal, and bladder carcinomas. Although paclitaxel can inhibit tumor development and improve survival, poor solubility, myelotoxicity, allergic reactions, and drug resistance have restricted its clinical application. Paclitaxel is frequently combined with other chemotherapeutics to enhance the antitumor effects and reduce side effects. We synthesized geridonin, a derivative of oridonin, and demonstrate that geridonin and paclitaxel act synergistically to inhibit the growth of gastric cancer cells. Importantly, geridonin enhanced the antitumor effects of paclitaxel without increasing toxicity in vivo. Mechanistic analysis revealed that administration of geridonin in combination with paclitaxel up-regulated the tumor suppressor PTEN and inhibited phosphorylation of Akt and MDM2. This led to the accumulation of p53 and induced apoptosis though the mitochondrial pathway. Thus, geridonin in combination with paclitaxel is a new treatment strategy for gastric cancer.

LPE-1, an orally active pyrimidine derivative, inhibits growth and mobility of human esophageal cancers by targeting LSD1

&NA; Histone lysine specific demethylase 1 (LSD1) plays an important role in epigenetic modifications, and aberrant expression of LSD1 predicts tumor progression and poor prognosis in human esophageal cancers. In this study, a series of LSD1 inhibitors were synthesized and proved to be highly potent against human esophageal squamous cell carcinoma (ESCC). Our data showed that these LSD1 inhibitors selectively suppressed the viability of esophageal cancer cell line (EC‐109) bearing overexpressed LSD1. Among these, compound LPE‐1 (LSD1 IC50 = 0.336 ± 0.003 &mgr;M) significantly suppressed proliferation, induced apoptosis, arrested cell cycle of EC109 cells at G2/M phase, and caused changes of the associated protein markers correspondingly. We also found that compound LPE‐1 potently inhibited the migration and invasion of EC‐109 cells. Docking studies showed that the cyano group formed hydrogen bonds with Val811 and Thr810. Additionally, the thiophene moiety formed arene‐H interaction with Trp761 residue. In vivo studies showed that compound LPE‐1 inhibited tumor growth of xenograft models bearing EC‐109 without obvious toxicity. Collectively, our findings indicate that LSD1 may be a potential therapeutic target in ESCC, and compound LPE‐1 could serve as a lead compound for further development for anti‐ESCC drug discovery. Graphical abstract Figure. No caption available.

Discovery of 5-cyano-6-phenylpyrimidin derivatives containing an acylurea moiety as orally bioavailable reversal agents against P-glycoprotein-mediated mutidrug resistance

P-glycoprotein (ABCB1)-mediated multidrug resistance (MDR) has become a major obstacle in successful cancer chemotherapy, which attracted much effort to develop clinically useful compounds to reverse MDR. Here, we designed and synthesized a novel series of derivatives with a 5-cyano-6-phenylpyrimidine scaffold and evaluated their potential reversal activities against MDR. Among these compounds, 55, containing an acylurea appendage, showed the most potent activity in reversing paclitaxel resistance in SW620/AD300 cells. Further studies demonstrated 55 could increase accumulation of PTX, interrupt ABCB1-mediated Rh123 accumulation and efflux, stimulate ABCB1 ATPase activity, and especially have no effect on CYP3A4 activity, which avoid drug interaction caused toxicity. More importantly, 55 significantly enhanced the efficacy of PTX against the SW620/AD300 cell xenograft without obvious side effects for orally intake. Given all that, the pyrimidine-acylurea based ABCB1 inhibitor may be a promising lead in developing new efficacious ABCB1-dependent MDR modulator.

Novel 3-(2,6,9-trisubstituted-9H-purine)-8-chalcone derivatives as potent anti-gastric cancer agents: Design, synthesis and structural optimization

To explore anti-gastric cancer agents with high efficacy and selectivity, we report the design, synthesis and optimization of a novel series of 3-(2,6,9-trisubstituted-9H-purine)-8-chalcone derivatives starting from the compound PCA-15 reported by us previously. Most of the target compounds demonstrated significant antiproliferative effects on MGC803 cancer cell line, and more potent than the positive control (PCA-15 and 5-Fu). Among them, compound 6o was identified to be the most active compound against MGC803 cell line with an IC50 value of 0.84 μM. Additionally, high selectivity was also observed between cancer and normal cells (23.35 μM against GES-1). Further mechanism studies confirmed that compound 6o could inhibit colony formation and migration, induce the apoptosis of MGC803 cells through both the mitochondrial-mediated intrinsic pathway and death receptor-mediated extrinsic pathway, which were evidenced by the up-regulation of Bax, cleaved-caspase 9/3/8, cleaved PARP and down-regulation of Bcl-2. Our systematic studies implied a new scaffold targeting gastric cancer cells for further development of small-molecule compounds with improved potency and selectivity.

Design, synthesis and in vitro biological evaluation of novel [1,2,3]triazolo[4,5-d]pyrimidine derivatives containing a thiosemicarbazide moiety.

A series of hybrid molecules containing [1,2,3]triazolo[4,5-d]pyrimidine and thiosemicarbazide moieties were designed, synthesized and evaluated for their antiproliferative activities against MGC-803, NCI-H1650 and PC-3 human cancer cells. Some of the synthesized compounds showed moderate to good activity against three selected cancer cell lines. Among these compounds, compound 29 displayed the most potent antiproliferative activity as well as good selectivity between cancer cells and normal cells. Further mechanism studies revealed that compound 29 could obviously inhibit the colony formation and migration of MGC-803 as well as induced apoptosis.

Discovery of 6-chloro-2-(propylthio)-8,9-dihydro-7H-purines containing a carboxamide moiety as potential selective anti-lung cancer agents

A new series of 6-chloro-2-(propylthio)-8,9-dihydro-7H-purine-8-caboxamide derivatives were designed, synthesized, and further evaluated for their antiproliferative activities on four human cancer cell lines (A549, MGC803, PC-3 and TE-1). The structure-activity relationships (SARs) studies were conducted through the variation in the two regions, which including position 8 and 9, of purine core. One of the compounds, 8, containing a terminal piperazine appendage with a carboxamide moiety at position 8 and phenyl group at position 9 of 6-chloro-8,9-dihydro-7H-purine core, showed the most potent antiproliferative activity and good selectivity between cancer and normal cells (IC50 values of 2.80 μM against A549 and 303.03 μM against GES-1, respectively). In addition, compound 8 could inhibit the colony formation and migration of A549 cells in a concentration-dependent manner, as well as induce the apoptosis possibly through the intrinsic pathway.

Abstract 3813: Potent compounds targeting the human MutT homolog 1 (hMTH1) activity and their cytotoxicity evaluation

Recently, it has been reported that MTH1, a sanitizing protein for the oxidized dNTP pool, plays an important role in cancer-associated damage in the dNTP pool and is required for survival in cancer cells. To study the antitumor mechanism of MTH1 and screen effective anti-cancer drugs, the current study was designed to set up an in vitro expressing and activity evaluation system for MTH1, which will be used for MTH1 specific inhibitor screening. Briefly, the acquired recombinant vector pET-28b-MTH1 was transfected into E.Coli BL21(DE3). The MTH1 protein expression was induced by IPTG and purified by Ni2+ affinity chromatography. Through converting dGTP to dGMP and pyrophosphate by MTH1, the latter of which can then be hydrolyzed to inorganic pyrophosphate by inorganic pyrophosphatase, the MTH1 activity is evaluated through measuring the amount of inorganic pyrophosphate after reacting with malachite green and ammonium molybdate at 630nm. Using this method, we have successfully generated a reliable in vitro evaluation system for MTH1 activity. Furthermore, five brand new series of hybrids with total more than one hundred compounds were virtually designed and synthesized. Their potential MTH1 inhibitory effects were screened based on our system. We found that some of them exhibited moderate to excellent inhibitory activity toward MTH1 with nanomole IC50 values, which also showed significant cytotoxicity on several gastric cancer cell lines by MTT assay (with IC50 below 10μM). On the other hand, our studies in human gastric cancer patients also indicated that MTH1 expression levels were significantly enhanced in these patients’ cancer tissues, compared to the para-cancer ones. Our findings suggest that MTH1 may be a potential therapeutic target in gastric cancer. Compounds specifically designed to target MTH1 activity may represent a novel and useful strategy for anti-gastric cancer drug discovery. *Corresponding author: Wen Zhao, Ph.D, Tel.: 01186-15003898187. Email: zhaowen100@139.com Funding Sources. This work was supported by National Natural Science Foundation of China (Project No. 81430085, No. 21372206 and No. 81172937 for H.-M.L.; Project No. 81270270 and No. 81470524 for W.Z.); Ph.D Educational Award from Ministry of Education (No. 20134101130001, for H.-M.L. and No. 20134101110013, for W.Z.); The 2013 Scientific Innovation Talent Award from Department of Education of Henan Province (No. 13HASTIT029, for W.Z.). Citation Format: Wenjuan Zhou, Liying Ma, Biao Hu, Lingyu Li, Bo Wang, Hong-Min Liu, Wen Zhao. Potent compounds targeting the human MutT homolog 1 (hMTH1) activity and their cytotoxicity evaluation. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3813.