Therapeutic effect of the sulforaphane derivative JY4 on ulcerative colitis through the NF-κB-p65 pathway.

The efficacy of the sulforaphane derivative JY4 was evaluated in acute and chronic mouse models of ulcerative colitis induced by dextran sodium sulfate. Oral administration of JY4 led to significant improvements in symptoms, with recovery of body weight and colorectal length, together with reduced diarrhoea, bloody stools, ulceration of colonic tissue and infiltration of inflammatory cells. The oral bioavailability of JY4, determined by comparing oral dosing with injection into the tail vein, was 5.67%, which was comply with the idea in the intestinal function. Using a dual-luciferase reporter assay, immunofluorescence studies, western blot analysis and immunohistochemical staining, JY4 was shown to significant interfere with the NF-κB-p65 signaling pathway. By preventing the activation of NF-κB-p65, JY4 inhibited the overexpression of downstream inflammatory factors, thereby exerting an anti-inflammatory effect on the intestinal tract. This study thus provides a promising candidate drug, and a new concept for the treatment of ulcerative colitis.

A small molecule compound IX inhibits telomere and attenuates oncogenesis of drug-resistant leukemia cells.

Drug resistance is a common obstacle in leukemia treatment and failing to eradicate leukemia stem cells is the main cause of leukemia relapse. Previous studies have demonstrated that telomerase activity is associated with deregulated self-renewal of leukemia stem cells (LSCs). Here, we identified a novel compound IX, an imatinib derivative with a replacement fragment of a telomerase inhibitor, which can effectively eradicate LSCs but had no influence on normal hematopoietic stem cells (HSCs) survival. We showed that compound IX can decrease the viability of drug-resistant K562/G cells and blast crisis CML primary patient cells. Besides, IX can affect LSC survival, inhibit the colony-forming ability, and reduce LSC frequency. In vivo results showed that IX can relieve the tumor burden in patient-derived xenograft (PDX) model and prolong the lifespan. We observed that compound IX can not only decrease telomerase activity, but also affect the alternative lengthening of telomeres. In addition, IX can inhibit both the canonical and non-canonical Wnt pathways. Our data suggested this novel compound IX as a promising candidate for drug-resistant leukemia therapy.

Design and synthesis of novel dasatinib derivatives as inhibitors of leukemia stem cells.

We used the concept of bioisosteres to design and synthesize a novel series of dasatinib derivatives for the treatment of leukemia. Unfortunately, most of the dasatinib derivatives did not show appreciable inhibition against leukemia cell lines K562 and HL60. However, acrylamide compound 2c had comparable inhibitory activity with dasatinib against K562 cells (IC50 = 0.039 nM vs. 0.069 nM). And amide compound 2a and acrylamide compound 2c also had comparable inhibitory activity with dasatinib against the leukemia cell line HL60 (IC50 = 0.25 nM and 0.26 nM vs. 0.11 nM). Against the leukemia progenitor cell line KG1a, triazole compounds 15a and 15d-15f and oxadiazole compounds 24a-24d were more potent than dasatinib. In particular, the hydroxyl compounds 15a and 24a were about 64 and 180 fold more potent than dasatinib against KG1a cells (IC50 = 0.14 µM and 0.05 µM vs. 8.98 µM). Compounds 15a and 24a also inhibited colony formation in MCF-7 cells and inhibited cell migration in the cell wound scratch assay in B16BL6 cells. Moreover, hydroxyl compounds 15a and 24a had low toxicity in vivo.

Therapeutic effects of isothiocyanate prodrugs on rheumatoid arthritis.

Isothiocyanates 7a and 7b have poor stability and aqueous solubility. To address these problems, prodrugs 8a and 8b were synthesized. Prodrugs 8a and 8b were stable in HEPES buffer at pH 4.4, but released the active compounds 7a and 7b in HEPES buffer at pH 7.4 and in mouse plasma, respectively. Compound 8a and especially compound 8b showed anti-inflammatory effects. Compound 8b demonstrated significant efficacy in animal models of traumatic inflammation, acute inflammation and rheumatoid arthritis. Compound 8b also did not cause appreciable toxicity in mice after 5 weeks at a daily dose of 200 mg/kg.

Cyclic Depsipeptide BE-43547A2 : Synthesis and Activity against Pancreatic Cancer Stem Cells.

Asymmetric total synthesis of the cyclic depsipeptide BE-43547A2 was achieved in 15 linear steps on a 350 mg scale in one batch. The synthesis features the highly diastereoselective construction of an α-hydroxy-ß-ketoamide through α-hydroxylation with a d.r. of up to 86:1. BE-43547A2 significantly reduces the percentage of pancreatic cancer stem cells (PCSCs) in Panc-1 cell cultures, and dramatically reduces the tumorsphere-forming capability of Panc-1 cells. An in vivo tumor-initiation assay, a gold standard for cancer stem cell assays, confirmed that BE-43547A2 can abolish the tumorigenesis of Panc-1 cells. The anti-PCSC activity of BE-43547A2 could make this depsipeptide scaffold a promising starting point for discovering new PCSC-targeting drugs.

Syntheses and biological evaluation of 1,2,3-triazole and 1,3,4-oxadiazole derivatives of imatinib.

Three novel series of 1,2,3-triazole and 1,3,4-oxadiazole derivatives of imatinib were prepared and evaluated in vitro for their cytostatic effects against a human chronic myeloid leukemia (K562), acute myeloid leukemia (HL60), and human leukemia stem-like cell line (KG1a). The structure-activity relationship was analyzed by determining the inhibitory rate of each imatinib analog. Benzene and piperazine rings were necessary groups in these compounds for maintaining inhibitory activities against the K562 and HL60 cell lines. Introducing a trifluoromethyl group significantly enhanced the potency of the compounds against these two cell lines. Surprisingly, some compounds showed significant inhibitory activities against KG1a cells without inhibiting common leukemia cell lines (K562 and HL60). These findings suggest that these compounds are able to inhibit leukemia stem-like cells.

Sulforaphane Analogues with Heterocyclic Moieties: Syntheses and Inhibitory Activities against Cancer Cell Lines.

Recent studies have shown that sulforaphane (SFN) selectively inhibits the growth of ALDH⁺ breast cancer stem-like cells.Herein, a series of SFN analogues were synthesized and evaluated against breast cancer cell lines MCF-7 and SUM-159, and the leukemia stem cell-like cell line KG-1a. These SFN analogues were characterized by the replacement of the methyl group with heterocyclic moieties, and the replacement of the sulfoxide group with sulfide or sulfone. A growth inhibitory assay indicated that the tetrazole analogs 3d, 8d and 9d were significantly more potent than SFN against the three cancer cell lines. Compound 14c, the water soluble derivative of tetrazole sulfide 3d, demonstrated higher potency against KG-1a cell line than 3d. SFN, 3d and 14c significantly induced the activation of caspase-3, and reduced the ALDH⁺ subpopulation in the SUM159 cell line, while the marketed drug doxrubicin(DOX) increased the ALDH⁺ subpopulation.

Simplified captopril analogues as NDM-1 inhibitors.

Captopril is a New Delhi metallo-ß-lactamase-1 (NDM-1) inhibitor with an IC50 value of 7.9µM. It is composed of two units: a 3-mercapto-2-methylpropanoyl fragment and a proline residue. In this study, we synthesized simple amide derivatives of 3-mercapto-2-methylpropanoic acid, and then tested them as NDM-1 inhibitors in order to identify the pharmacophore for NDM-1 inhibition. We found that the lead compound 22 had an IC50 value of 1.0µM. Further structure simplification provided compounds 31 and 32, which had IC50 values of 15 and 10µM, respectively. As compound 32 is a clinically used antidote for metal poisoning, it has great potential to be repurposed to treat bacterial infections.

Synthesis of ponatinib analogues as novel inhibitors of leukemia stem cells.

Aim: To synthesize new analogues of ponatinib and evaluate anti-leukemia cells and cytotoxicity. Methodology & results: The inhibitory activity of compounds 13a and 13c against K562 and HL60 cells was comparable to that of ponatinib (IC50 = 0.74, 0.88 vs 0.64 nM and 0.59, 0.77 vs 0.39 nM, respectively). Compounds 13a and 40b were 34- and 77-fold more potent than ponatinib against KG1a cells (IC50 = 0.091 and 0040 vs 3.6 µM, respectively). Compounds 13a, 13c and 40b also decreased the Abl protein level in the K562 cells, inhibited colony formation in MCF-7 cells and inhibited cell migration in B16BL6 cells. Compound 13a showed low cytotoxicity in 293 cells. Conclusion: Compound 13a was the best lead compound.

[The Effect and Mechanism of Novel Telomerase Inhibitor Nilo 22 on Leukemia Cells].

OBJECTIVE: To investigate the cytotoxic effect and its mechanism of the micromolecule compound on the leukemia cells. METHODS: The cytotoxic effects of 28 Nilotinib derivatives on K562, KA, KG, HA and 32D cell lines were detected by MTT assays, and the compound Nilo 22 was screen out. Cell apoptosis and cell cycle on leukemia cells were detected by flow cytometry. The effect of compound screened out on leukemogenesis potential of MLL-AF9 leukemia mice GFP+ cells was tested by colony-forming units assays (CFU). The cytotoxic effect was further detected by transplant assays ex vivo. Telomerase activity assay, C-circle assay were used to measure the effects of compound on the length mechanism of telomere, RT-PCR was used to detected the changes of telomere. RESULTS: Nilo 22 serves as the most outstanding candidate out of 28 Nilotinib derivatives, which impairs leukemia cell lines, but spares normal hematopoietic cell line. Comparing with Nilotinib, Nilo 22 could induce the apoptosis of GFP+ cells significantly, slightly arrests the cell cycle at G0/G1 phase, and significantly inhibits colony formation and prolong the progression in MLL-AF9 leukemia mice model. The expression showed that the compound could slow the disease progression in MLL-AF9 leukemia mice significantly. Mechanistically, Nilo 22 could reduce the length of telomere by inhibiting telomerase activity and alternative lengthening of telomere (ALT). CONCLUSION: Nilo 22 shows a significant cytotoxic effect on mice and human leukemia cells, especially for drug resistance cells. Nilo 22 is a promising anti-leukemia agent to solve the common clinical problems of drug resistance and relapse of leukemia.

Design, synthesis and evaluation of novel phenothiazine derivatives as inhibitors of breast cancer stem cells.

A novel series of phenothiazine derivatives containing diethanolamine, methoxyethylamine, flavonoids, and a nitric oxide (NO) donor was designed and synthesized for the treatment of breast cancer. Phenothiazine derivatives (l) did not noticeably inhibit the growth of SUM159, MDA-MB-231, MCF-7, and SKBR-3 cells, whereas phenothiazine derivatives (ll) containing the NO donor were more potent or had comparable inhibitory activity to trifluoperazine (TFP) and thioridazine against SUM159, MDA-MB-231, MCF-7, and SKBR-3 cells. Compounds 20a-c and 21a-c showed the strongest activity in SUM159, MDA-MB-231, MCF-7, and SKBR-3 cells, and more potent inhibitory activity than TFP against KG1a cells (IC50 = 1.63, 2.93, 1.14, 1.78, 2.20, and 1.20 vs. 4.58 µM). Compounds 20a and 21a had lower toxicity than compounds 20b-c and 21b-c, and inhibited colony formation in MCF-7 cells, decreased the formation of mammospheres in SUM159 cells, and inhibited the migration of MDA-MB-231 cells. Compounds 20a and 21a could inhibited pNF-κB-p65 as shown by dual-luciferase reporter assays and western blotting in MDA-MB-231 cells.

Syntheses and anti-pancreatic cancer activities of rakicidin A analogues.

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive malignant tumor and resistant to most therapies. Pancreatic cancer stem cells (PCSCs) had critical role in regulating PDAC progression, metastasis, and drug resistance. Therefore, targeting PCSCs is considered to be a promising strategy for treatment of PDAC. However, there is no effective drug that can selectively ablate PCSCs. A series of twenty rakicidin A analogues were synthesized via a combinatorial strategy and evaluated for their anti-PDAC activities, and the structure-activity relationship was also discussed. Compound 32g was prepared in 14 linear steps with 5.05% overall yield, which is much more efficient than our previously reported total synthesis of rakicidin A (19 linear steps with 0.19% yield). In a highly metastatic pancreatic cancer cell line ASPC-1, compound 32g showed about 4 times higher potency (IC50 = 0.022 µM) than rakicidin A (IC50 = 0.082 µM) at hypoxia condition, and 12 folds of hypoxia selectivity (IC50 = 0.27 µM at nomoxia condition). In contrast, the activity of adriamycin in the same hypoxic condition decreased. The percentage of PCSCs (with CD24+CD44+ESA+ biomarker), activity of ALDH, and the number of tumorspheres in PANC-1 cells were greatly reduced after treatment of 32g. More importantly, the tumor-initiating frequency was reduced by 19 folds after the treatment of 32g, which is better than that of rakicidin A (reduction of 4.7 folds).

Structure-Activity Relationship Study of Rakicidins: Overcoming Chronic Myeloid Leukemia Resistance to Imatinib with 4-Methylester-Rakicidin A.

Natural product rakicidin A induces cell death in TKI-resistant chronic myelogenous leukemia (CML) cells. Therefore, 14 rakicidin A analogues were synthesized via a highly efficient combinatorial strategy and were evaluated against CML cell lines. The conjugated diene moiety was found to be crucial for the anti-CML activity of rakicidin A, and the changes in the configuration(s) at C-2, C-3, C-14, C-15, and C-16 resulted in lower levels of anti-CML activity. The most promising compound was 4-methylester rakicidin A (1a). Compared with rakicidin A, 1a exhibited 2.8-fold greater potency against the imatinib-resistant cell line K562/G(+) and approximately 100-fold enhanced potency compared with that of imatinib. Furthermore, compound 1a demonstrated a significantly lower resistance index against Ba/F3 cells expressing BCR-ABL(T315I) than bosutinib, dasatinib, nilotinib, and ponatinib, while 1a exhibited less effect on normal hematopoietic cells. Preliminary results indicated that 1a down-regulated caspase-3 and PARP, which contributes to its K562 cell inhibitory activity.