TYM-3-98, a novel selective inhibitor of PI3Kδ, demonstrates promising preclinical antitumor activity in B-cell lymphomas.

AIMS: PI3Kδ is expressed predominately in leukocytes and is commonly found to be aberrantly activated in human B-cell lymphomas. Although PI3Kδ has been intensively targeted for discovering anti-lymphoma drugs, the application of currently approved PI3Kδ inhibitors has been limited due to unwanted systemic toxicities, thus warranting the development of novel PI3Kδ inhibitors with new scaffolds. MAIN METHODS: We designed TYM-3-98, an indazole derivative, and evaluated its selectivity for all four PI3K isoforms, as well as its efficacy against various B-cell lymphomas both in vitro and in vivo. KEY FINDINGS: We identified TYM-3-98 as a highly selective PI3Kδ inhibitor over other PI3K isoforms at both molecular and cellular levels. It showed superior antiproliferative activity in several B-lymphoma cell lines compared with the approved first-generation PI3Kδ inhibitor idelalisib. TYM-3-98 demonstrated a concentration-dependent PI3K/AKT/mTOR signaling blockage followed by apoptosis induction. In vivo, TYM-3-98 showed good pharmaceutical properties and remarkably reduced tumor growth in a human lymphoma xenograft model and a mouse lymphoma model. SIGNIFICANCE: Our findings establish TYM-3-98 as a promising PI3Kδ inhibitor for the treatment of B-cell lymphoma.

A novel sesquiterpene lactone fraction from Eupatorium chinense L. suppresses hepatocellular carcinoma growth by triggering ferritinophagy and mitochondrial damage.

BACKGROUND: Hepatocellular carcinoma (HCC) is an aggressive tumor with limited treatment options, and it is the third leading cause of cancer-related deaths. Hence, novel therapeutic strategies are required to treat HCC. Eupatorium chinense L. is a traditional Chinese medicine (TCM) that can effectively neutralize heat and smoothen the flow of "Qi" through the liver. However, the anti-HCC effects of Eupatorium chinense L. remain unknown. PURPOSE: The present study investigated the anti-HCC effects and the underlying mechanisms of the electrophilic sesquiterpenes isolated from E. chinense L. (EChLESs) in the regulation of ferroptosis and apoptosis in HCC cells. STUDY DESIGN/METHODS: Cell viability was assessed by the MTT assay. Cell apoptosis was confirmed by flow cytometry and western blotting assay. Ferroptosis was assessed by flow cytometry, transmission electron microscopy, and western blotting assay. Ferritinophagy was detected by acridine orange staining and western blotting assay. Small interfering RNA of nuclear receptor coactivator 4 (NCOA4) was used to confirm the role of ferritinophagy in the therapeutic effect of EChLESs on HCC cells. A mouse xenograft model was constructed to determine the inhibitory effect of EChLESs on HCC in vivo. RESULTS: EChLESs induced apoptosis by disrupting mitochondrial membrane potential depolarization and mitochondrial reactive oxygen species. EChLESs induced ferroptosis as noted by a significant increase in mitochondrial disruption, lipid peroxidation, and intracellular iron level and decreased glutathione level. The apoptosis inhibitor Z-VAD-FMK and lipid reactive oxygen species scavenger ferrostatin 1 attenuated EChLESs-induced cell death. NCOA4-mediated ferritinophagy through autophagic flux was the crucial pathway for ferroptosis induced by EChLESs. NCOA4 knockdown alleviated EChLESs-induced cell death. EChLESs controlled the expression of NCOA4 at the transcriptional and post-transcriptional levels. In the in vivo experiment, EChLESs suppressed HCC growth in the xenograft tumor mouse model. CONCLUSION: EChLESs enhances cell apoptosis through mitochondrial dysfunction and ferroptosis through NCOA4-mediated ferritinophagy. Thus, Eupatorium chinense L. could be a potential TCM for treating HCC.

Design, synthesis, and biological evaluation of C-8 modified curcumol derivatives against colorectal cancer cell lines.

A series of structurally modified curcumol derivatives at C-8 position were designed and synthesized, whose structures were confirmed by 1H NMR,13C NMR, and HRMS analysis. The tested compounds were evaluated for in vitro antitumor activity against colorectal cancer cell lines SW620, HCT116, and CaCo2. Many of the tested candidates exhibited higher inhibition efficiency than curcumol. Among them, compound 3 l shows the best inhibitory effect on the viability of SW620 with IC50 value of 19.90 ± 0.64 µM. The structure-activity relationships of these derivatives were discussed, which showed that the introduction of amino or aryl groups tended to increase the anti-cancer activity. In addition, compound 3 l may inhibit cancer cell proliferation through triggering cell apoptosis.

Design, synthesis, and anticancer activity evaluation of curcumol derivatives.

A new series of C-14 curcumol derivatives as potent anticancer agents were designed and synthesized by click reaction, whose structures were confirmed by 1H NMR,13C NMR, and HRMS analysis. All the synthesized compounds were evaluated for in vitro antitumor activity against colorectal cancer cell lines SW620 and HCT116. Most of them exhibited higher inhibitory activity than curcumol. Especially, compound 3j shows good inhibitory activity against SW620 with IC50 value of 8.10 ± 0.13 µM. The structure-activity relationships (SARs) of these derivatives were discussed. In addition, flow cytometry revealed that compound 3j induced SW620 cells apoptosis by facilitating apoptosis-related proteins expressions. Our findings suggested that fluorine functional group on phenyl ring tended to increase the anticancer activity.

L1CAM is involved in lymph node metastasis via ERK1/2 signaling in colorectal cancer.

L1-cell adhesion molecule (L1CAM, L1) belongs to the immunoglobulin superfamily and was originally found to play a role in nerve cells. Recently, the expression and prognostic value of L1 has been established in several cancers, including colorectal cancer (CRC). However, its association with lymph node metastasis in CRC and the mechanisms underlying its effects remain unclear. In this study, we evaluated the L1 transcript levels in CRC (n=12) and normal intestinal tissues (n=15) by qRT-PCR. Western blotting was used to evaluate L1 and pERK1/2 expression levels. Immunohistochemistry was performed to evaluate the relationship between L1 and pERK1/2 in CRC tissues with different levels of differentiation. The mRNA expression levels in CRC tissues were significantly higher compared to normal intestinal tissues. Western blotting demonstrated that both L1 and pERK1/2 levels were higher in CRC than in normal tissues. Immunohistochemistry confirmed that L1 and pERK1/2 levels in adenomas with lymph node metastasis were significantly higher than in poorly and well-differentiated adenomas, indicating that L1 and pERK1/2 levels correlated with CRC lymph node metastasis. In conclusion, L1 and pERK1/2 were significantly up-regulated in CRC tissues and lymph node metastasis may occur via the L1CAM-mediated ERK pathway in CRC.

Precise discovery of a STAT3 inhibitor from Eupatorium lindleyanum and evaluation of its activity of anti-triple-negative breast cancer.

Michael reaction acceptors (MRAs) are a class of active compounds. There is a great prospect to screen STAT3 inhibitors from Eupatorium lindleyanum, furthermore, to discover lead compounds for anti-triple-negative breast cancer (TNBC). In this study, glutathione (GSH) was employed, and a UPLC-MS screening method was developed to discover MRAs. We screened MRAs which can inhibit STAT3 using a STAT3-dependent reporter system. Six sesquiterpene lactones, including a new compound Eupalinolide O (1), together with five known compounds, Eupalinolide I (2), Eupalinolide K (3), Eupalinolide H (4), Eupalinolide J (5) and Eupalinolide G (6) were isolated. Eupalinolide J was identified as MRA that decreased luciferase activity of STAT3. Preliminary activity assessment showed that Eupalinolide J could inhibit the viability of TNBC cell lines. We demonstrated that Eupalinolide J, which is a natural typical MRA, has a notable inhibition of STAT3 activity and a potential cytotoxic activity against TNBC cell lines.

Polysaccharide from Phellinus Igniarius activates TLR4-mediated signaling pathways in macrophages and shows immune adjuvant activity in mice.

Polysaccharide from Phellinus igniarius (PPI) is known for its immune-regulating effect with low toxicity. Toll like receptor 4 (TLR4) is important in both innate and adaptive immune responses and considered to be a promising target for new immune adjuvants. In this study, PPI was investigated for its effect on activating TLR4 in RAW264.7 and peritoneal macrophages. The adjuvant potential of PPI was evaluated in OVA-immunized mice. The results showed PPI treatment significantly increased the secretion and the mRNA expression of both MyD88 dependent and TRIF dependent cytokines. IRAK-1, a key molecule on the downstream of MyD88, was polyubiquitinated while IRF-3, another key molecule on the downstream of TRIF, was phosphorylated obviously after the treatment of PPI. The phosphorylation of molecules involved in both NF-κB pathway and MAPK pathway were significantly up-regulated after PPI treatment. In addition, the effects of PPI on the macrophages almost completely disappeared after treating the cells with the TLR4 antagonist TAK-242. Further in vivo results showed PPI significantly increased the serum OVA-specific antibody and the OVA-specific spleen cell proliferation. Taken together, PPI can specifically stimulate TLR4 and activate both MyD88 and TRIF pathways. PPI has immune adjuvant activity and may become a new potential immune adjuvant.

A new five-coordinated copper compound for efficient degradation of methyl orange and Congo red in the absence of UV-visible radiation.

A new copper-based coordination compound Cu2(2,2'-bipy)2(pfbz)4 (1) (where 2,2'-bipy = 2,2'-bipyridine; pfbz = pentafluorobenzoate), was hydrothermally synthesized and structurally characterized. Compound 1 having a binuclear structure consists of two copper cations and two oxygen atoms alternately in a plane square arrangement. In the presence of very small amounts of H2O2, the catalytic properties of compound 1 for the degradation of methyl orange (MO) are excellent in the absence of UV-visible radiation. Moreover, compound 1 presents suitable properties for degradation of Congo red (CR). Our results indicated that the five-coordinated copper compound, 1, will be a promising candidate for efficient degradation of organic dyes.

The Loss of a Sugar Chain at C(3) Position Enhances Stemucronatoside K-Induced Apoptosis, Cell Cycle Arrest, and Hedgehog Pathway Inhibition in HT-29 Cells.

Stemucronatoside K (SMK) and its aglycone stephanthraniline A (STA) are the most representative of a series of novel C21 steriodal compounds that we have previously isolated from Asclepiadaceae plants. The objectives of this study were to investigate the antitumor activity of SMK and STA, and clarify the effect of the sugar chain at the C(3) position. Our results showed that both SMK and STA decreased the growth of HT-29 cells in a dose- and time-dependent manner. Meanwhile, STA showed much stronger inhibitory effect than SMK. Treatment of HT-29 cells with STA increased the apoptotic cell numbers and the protein expression of cleaved caspase 3 and cleaved-PARP. G1 phase cell cycle arrest and decreased expression of cyclin D1 and cyclin-dependent kinases 4 were also observed after STA treatment. Furthermore, STA reduced the mRNA levels of four Hedgehog pathway components (GLI1, GLI2, GLI3, and PTCH1) and suppressed Shh-induced Hedgehog pathway activation in a concentration-dependent manner. These results indicated that SMK and STA could inhibit the growth of HT-29 cells by inducing apoptosis, cell cycle arrest, and hedgehog pathway inhibition. The loss of sugar chain at C(3) position could enhance SMK's activity. This study is beneficial to understand the use of natural C21 steroids as antitumor lead compounds.

Combined inhibition of EGFR and c-ABL suppresses the growth of triple-negative breast cancer growth through inhibition of HOTAIR.

Triple-negative breast cancer (TNBC) does not express conventional therapeutic targets and is the only type of malignant breast cancer for which no designated FDA-approved targeted therapy is available. Although overexpression of epidermal growth factor receptor (EGFR) is frequently found in TNBC, the therapeutic effect of EGFR inhibitors in TNBC has been underwhelming. Here we show that co-treatment with clinically validated inhibitors of c-ABL (imatinib) and EGFR (lapatinib) results in synergistic growth inhibition in TNBC cells. The dual treatment leads to synergistic repression of the long non-coding RNA (lncRNA) HOTAIR (HOX Antisense Intergenic RNA). HOTAIR has been known to induce tumor growth and metastasis in breast cancer. Depleting HOTAIR alone phenocopies the dual treatment in growth suppression. We show that expression of HOTAIR is regulated by ß-catenin through a LEF1/TCF4-binding site. The dual treatment blocks nuclear expression of ß-catenin and prevents its recruitment to the HOTAIR promoter. Consistently, forced expression of ß-catenin rescued HOTAIR expression and cell viability in the presence of both drugs. Upregulation of HOTAIR is associated with TNBC in cell lines and a cohort of primary tumors. This study elucidates a previously unidentified mechanism in TNBC linking signaling with lncRNA regulation which may be exploited for therapeutic gain.

MFTZ-1, an actinomycetes subspecies derived antitumor macrolide, functions as a novel topoisomerase II poison.

14-Ethyl-2,5,11-trimethyl-4,13,19,20-tetraoxa-tricyclo[14.2.1.1(7,10)]eicosane-3,12-dione (MFTZ-1), a new macrolide compound isolated from Streptomyces sp. Is9131, displayed wide cytotoxicity in human tumor cell lines with an average IC(50) of 0.905 micromol/L. Notably, MFTZ-1 showed significant cytotoxicity in the three multidrug resistance cell lines with an average resistance factor of 2.08. The in vivo experiments showed that MFTZ-1 had inhibitory effects on the human ovarian carcinoma HO-8910 cell line xenotransplanted in nude mice. Further studies showed that MFTZ-1 induced DNA double-strand breaks and triggered mitochondria-dependent apoptosis in human leukemia HL-60 cells. Using a yeast genetic system, we found that topoisomerase (Topo) II rather than Topo I was the primary cellular target of MFTZ-1. Most importantly, MFTZ-1 functions as a novel nonintercalative Topo II poison via binding to ATPase of Topo II, characterized by its strong inhibition on the decatenation and relaxation of Topo II. The capacity of MFTZ-1 to stabilize Topo II-DNA covalent complexes was comparable with that of the classic Topo II poison, etoposide. Moreover, using a Topo II catalytic inhibitor aclarubicin and Topo II-deficient HL-60/MX2 cells, we further showed that MFTZ-1-triggered DNA double-strand breaks and apoptosis occurred in a Topo II-dependent manner. Together, the well-defined Topo II-poisoning function and the potent antitumor activity, with the appreciable anti-multidrug resistance action in particular, promises MFTZ-1 as a novel potential Topo II-targeted agent, which merits further research and development.

Silencing of heparanase by siRNA inhibits tumor metastasis and angiogenesis of human breast cancer in vitro and in vivo.

Expression of the heparanase gene is associated with invasive, angiogenic and metastatic potential of diverse malignant tumors and cell lines. Here we used RNA interference strategies to evaluate the role of human heparanase in breast malignancy and to explore the therapeutic potential of its specific targeting. The siRNA targeting human heparanase almost completely inhibited the expression of heparanase in human breast carcinoma MDA-MB-435 cells, whereas the mismatched siRNA showed no effect. Cells transfected with heparanase siRNA expressed significantly less heparanase and profoundly reduced invasion and adhesion in vitro. In MDA-MB-435 cell xenograft model, tumors treated with siRNA were less vascularized and less metastatic than those treated with saline and the mismatched controls. The association of reduced levels of heparanase and altered tumorigenic properties in cells with anti-heparanase siRNA indicates that heparanase is important in cancer progress and has potential use as a target for anticancer drug development.