Identification and pre-clinical investigation of 3-O-cyclohexanecarbonyl-11-keto-ß-boswellic acid as a drug for external use to treat psoriasis.

BACKGROUND AND PURPOSE: Psoriasis vulgaris is a refractory skin inflammatory disorder with 80% of the cases belonging to the mild-to-moderate type, which can be controlled by topical treatment. Nevertheless, the drugs for external use have not been upgraded for decades. We modified acetyl-11-keto-beta-boswellic acid (ABKA), a natural compound shown to treat psoriasis animal models, to improve efficacy and solubility for topical use. EXPERIMENTAL APPROACH: Eleven compounds were synthesized using AKBA as a lead compound, and their effects on Th17 cell differentiation were screened. 3-O-cyclohexanecarbonyl-11-keto-ß-boswellic acid (CKBA) potently inhibited Th17 cell differentiation. Its efficacy in a mouse model of psoriasis was assessed along with its pharmacology and safety profile when topically or systemically delivered to several animal species. KEY RESULTS: CKBA inhibited mouse and human Th17 cell differentiation with an IC50 of 3.28 and 3.61 µM, respectively, and directly targeted acetyl-CoA carboxylase 1 (ACC1). Safety evaluation and toxicity tests suggested that systemically delivered high-dose CKBA for 14 days had no dose-associated adverse effects on the CNS, haematopoietic, cardiovascular, respiratory and digestive systems of cynomolgus monkeys. CKBA ointment permeated the skin and did not irritate or sensitize intact skin. CKBA ointment mediated dose-dependent suppression of imiquimod-induced psoriasis-like skin inflammation with slow absorption and limited bioavailability (<10% in rats and <1% in minipigs). CONCLUSIONS AND IMPLICATIONS: CKBA is safe when topically or systemically delivered to animals. The beneficial effects of CKBA ointment in a mouse model of psoriasis indicate that this is a promising drug candidate for further development as a treatment for psoriasis.

FBXO9 Mediates the Cancer-Promoting Effects of ZNF143 by Degrading FBXW7 and Facilitates Drug Resistance in Hepatocellular Carcinoma.

F-box proteins are critical for malignancy because they control the turnover of key proteins that govern multiple cellular processes. F-box protein 9 (FBXO9) belongs to the F-box protein family and exhibits oncogenic properties in hematological malignancies. However, the function and molecular mechanism of FBXO9 in hepatocellular carcinoma (HCC) remain unclear. Here, we report that FBXO9 was remarkably overexpressed in HCC. Loss- and gain-of-function experiments showed that FBXO9 facilitates HCC cell proliferation and metastasis both in vitro and in vivo. Mechanistically, as a direct upstream transcription factor, FBXO9 is regulated by zinc finger protein 143 (ZNF143) and accelerates tumor growth and metastasis by targeting the F-box and WD repeat domain containing 7 (FBXW7) for ubiquitination and degradation. Additionally, we found that with FBXO9 knockdown, HCC cells were more sensitive to treatment with lenvatinib and sorafenib. In summary, our results demonstrate that a ZNF143-FBXO9-FBXW7 signaling regulatory axis may be involved in tumor progression in HCC, and suggest that FBXO9 could be a potential biomarker and therapeutic target for HCC.

STAT5A modulates CDYL2/SLC7A6 pathway to inhibit the proliferation and invasion of hepatocellular carcinoma by targeting to mTORC1.

Chromodomain Y-like 2 (CDYL2), as a member of CDY family known to be involved in spermatogenesis, has been reported to participate in breast cancer development recently, but its exact biological role in hepatocellular carcinoma (HCC) remains unclear. Here, we observed that CDYL2 was down-regulated in human primary HCC tissues and the low levels of CDYL2 expression were correlated with poor survival. Gain- and loss-of-function experiments showed that CDYL2 inhibited the proliferation and metastasis of HCC cells in vitro and in vivo. Mechanistically, CDYL2 down-regulates solute carrier family 7 member 6 (SLC7A6) by decreasing the enrichment of H3K4me3 on the promoter region of SLC7A6. Additionally, we also found that signal transducer and activator of transcription 5A (STAT5A) could directly and positively regulate the expression of CDYL2. Thus, CDYL2 was regulated by STAT5A, and suppressed the amino acid transportation through down-regulation of SLC7A6, and then inhibits the mTORC1/S6K pathway, a master regulator of cell growth. Consistently, CDYL2 expression correlated significantly with STAT5A and SLC7A6 expression in HCC. Collectively, we propose a model for a STAT5A/CDYL2/SLC7A6 axis that provides novel insight into CDYL2, which may serve as a potential factor for predicting prognosis and a therapeutic target for HCC patients.

Structure-activity relationship study of novel quinazoline-based 1,6-naphthyridinones as MET inhibitors with potent antitumor efficacy.

As a privileged scaffold, the quinazoline ring is widely used in the development of EGFR inhibitors, while few quinazoline-based MET inhibitors are reported. In our ongoing efforts to develop new MET-targeted anticancer drug candidates, a series of quinazoline-based 1,6-naphthyridinone derivatives were designed, synthesized, and evaluated for their biological activities. The preliminary SARs studies indicate that the quinazoline scaffold was also acceptable for the block A of class II MET inhibitors. The further pharmacokinetic studies led to the identification of the most promising compound 22a with favorable in vitro potency (MET, IC50 = 9.0 nM), human microsomal metabolic stability (t1/2 = 621.2 min) and oral bioavailability (F = 42%). Moreover, 22a displayed good in vivo antitumor efficacy (IR of 81% in 75 mg/kg) in MET-positive human glioblastoma U-87 MG xenograft model. These positive results indicated that 22a is a potential new MET-targeted antitumor drug lead, which is worthy of further development.

MicroRNA-18a promotes cancer progression through SMG1 suppression and mTOR pathway activation in nasopharyngeal carcinoma.

miR-18a has been reported to be upregulated in nasopharyngeal carcinoma (NPC) tissues by microarray assays. However, the roles and the underlying mechanisms of miR-18a in NPC remain poorly understood. Here we demonstrated by real-time RT-PCR that miR-18a expression is upregulated in NPC tissues, and positively correlated with tumor size and TNM stage. Moreover, miR-18a expression could be upregulated by NF-κB activation or Epstein-Barr virus encoded latent membrane protein 1 expression. The ectopic expression of miR-18a promoted NPC cell proliferation, migration and invasion, while the repression of miR-18a had opposite effects. Candidate genes under regulation by miR-18a were screened out through a whole-genome microarray assay, further identified by a reporter assay and verified in clinical samples. SMG1, a member of the phosphoinositide 3-kinase-related kinases family and an mTOR antagonist, was identified as functional target of miR-18a. Our results confirmed that miR-18a exerts its oncogenic role through suppression of SMG1 and activation of mTOR pathway in NPC cells. Importantly, in vivo xenograft tumor growth in nude mice was effectively inhibited by intratumor injection of miR-18a antagomir. Our data support an oncogenic role of miR-18a through a novel miR-18a/SMG1/mTOR axis and suggest that the antitumor effects of antagomir-18a may make it suitable for NPC therapy.

miR-665 expression predicts poor survival and promotes tumor metastasis by targeting NR4A3 in breast cancer.

Cancer metastasis is the main cause of death in breast cancer (BC) patients. Therefore, prediction and treatment of metastasis is critical for enhancing the survival of BC patients. In this study, we aimed to identify biomarkers that can predict metastasis of BC and elucidate the underlying mechanism of the functional involvement of such markers in metastasis. miRNA expression profile was analyzed using a custom microarray system in 422 BC tissues. The relationship between the upregulated miR-665, metastasis and survival of BC was analyzed and verified in another set of 161 BC samples. The biological function of miR-665 in BC carcinogenesis was explored with in vitro and in vivo methods. The target gene of miR-665 and its signaling cascade were also analyzed. There are 399 differentially expressed miRNAs between BC and noncancerous tissues, of which miR-665 is the most upregulated miRNA in the BC tissues compared with non-tumor breast tissues (P < 0.001). The expression of miR-665 predicts metastasis and poor survival in 422 BC patients, which is verified in another 161 BC patients and 2323 BC cases from online databases. Ectopic miR-665 expression promotes epithelial-mesenchymal transition (EMT), proliferation, migration and invasion of BC cells, and increases tumor growth and metastasis of BC in mice. Bioinformatics, luciferase assay and other methods showed that nuclear receptor subfamily 4 group A member 3 (NR4A3) is a target of miR-665 in BC. Mechanistically, we demonstrated that miR-665 promotes EMT, invasion and metastasis of BC via inhibiting NR4A3 to activate MAPK/ERK kinase (MEK) signaling pathway. Our study demonstrates that miR-665 upregulation is associated with metastasis and poor survival in BC patients, and mechanistically, miR-665 enhances progression of BC via NR4A3/MEK signaling pathway. This study provides a new potential prognostic biomarker and therapeutic target for BC patients.

2,7-naphthyridinone-based MET kinase inhibitors: A promising novel scaffold for antitumor drug development.

As part of our effort to develop new molecular targeted antitumor drug, a novel 2,7-naphthyridone-based MET kinase inhibitor, 8-((4-((2-amino-3-chloropyridin-4-yl)oxy)- 3-fluorophenyl)amino)-2-(4-fluorophenyl)-2,7-naphthyridin-1(2H)-one (13f), was identified. Knowledge of the binding mode of BMS-777607 in MET led to the design of new inhibitors that utilize novel 2,7-naphthyridone scaffold to conformationally restrain the key pharmacophoric groups (block C). Detailed SAR studies resulted in the discovery of a new MET inhibitor 13f, displaying favorable in vitro potency and oral bioavailability. More importantly, 13f exhibited excellent in vivo efficacy (tumor growth inhibition/TGI of 114% and 95% in 50 mg/kg, respectively) both in the U-87 MG and HT-29 xenograft models. The favorable drug-likeness of 13f indicated that 2,7-naphthyridinone may be used a promising novel scaffold for antitumor drug development. The preclinical studies of 13f are under way.

MicroRNA­342­3p suppresses proliferation and invasion of nasopharyngeal carcinoma cells by directly targeting Cdc42.

Deregulated microRNAs play an important role in the development and progression of various types of cancer. In our previous study, we observed that microRNA­342­3p (miR­342­3p) was one of the most markedly downregulated microRNAs in two nasopharyngeal carcinoma (NPC) cell lines compared to non­neoplastic cells by using whole genome small RNA sequencing. In the present study, we confirmed that the expression of miR­342­3p was significantly reduced in NPC tissues compared with normal nasopharyngeal epithelial tissues. Overexpression of miR­342­3p inhibited proliferation, epithelial­mesenchymal transition (EMT), migration and invasiveness of NPC cells. In addition, we observed that Cdc42, a Rho GTPase family member involved in cell proliferation and metastasis, is a direct target of miR­342­3p. Additionally, ML141, a small­molecule inhibitor of Cdc42, efficiently suppressed the invasion of NPC cells compared with the control cells. Finally, we analyzed NPC tissues derived from 10 NPC patients and subjected them to quantitative RT­PCR and immunohistochemistry assays for concomitant determination of the expression levels of miR­342­3p and Cdc42. Our results revealed that miR­342­3p levels were significantly inversely correlated with the protein levels of its target Cdc42. The results of the present study indicated that miR­342­3p inhibited NPC tumor growth and invasion by directly targeting the Cdc42 pathway.

Identification of 4-(2-furanyl)pyrimidin-2-amines as Janus kinase 2 inhibitors.

Janus kinases inhibitor is considered to have therapeutic potential for the treatment of oncology and immune-inflammatory diseases. Two series of 4-(2-benzofuranyl)pyrimidin-2-amine and 4-(4,5,6,7-tetrahydrofuro[3,2-c]pyridin-2-yl)pyrimidin-2-amine derivatives have been designed and synthesized. Primary SAR studies resulted in the discovery of a novel class of 4,5,6,7-tetrahydrofuro[3,2-c]pyridine based JAK2 inhibitors with higher potency (IC50 of 0.7nM) and selectivity (>30 fold) to JAK3 kinase than tofacitinib.

Calycosin induces apoptosis in colorectal cancer cells, through modulating the ERß/MiR-95 and IGF-1R, PI3K/Akt signaling pathways.

Calycosin, the main component extractable from the herb Radix astragali, has been shown to inhibit cellular proliferation and induce apoptosis in several cancer cell lines, but the underlying mechanisms by the way in which this occurs remain unclear. In the present study, we aimed to determine the potential effects of calycosin on proliferation in colorectal cancer cells in vitro and in vivo and to elucidate the underlying molecular mechanisms of action. Colorectal cancer cell lines SW480 and LoVo and cervical cancer cell line HeLa were treated with various concentrations of calycosin or plus ER beta (ERß) inhibitor PHTPP. The CCK8 assay, flow cytometry, and Hoechst 33258 stain were used to assess the effects on cellular proliferation and apoptosis. The mRNA levels of ERß and miR-95 were quantified by real-time PCR. The protein expression levels of ERß, ERα, IGF-1R, and p-Akt were evaluated by Western blot analysis. We demonstrated that calycosin inhibited the proliferation in SW480 and LoVo cells and induced apoptosis, particularly in SW480 cells, but not in HeLa cells. Calycosin increased ERß expression and reduced the ERα, IGF-1R, and p-Akt expression alongside down-regulation of miR-95 in SW480 cells. Inhibiting ERß blocked the change of miR-95 and the resulting increase in apoptosis in SW480 cells. Additionally, calycosin significantly suppressed xenograft tumor growth in nude mice. In conclusion, calycosin exerts an inhibitory effect on proliferation of CRC cells in vivo and in vitro, through ERß-mediated regulation of the IGF-1R, PI3K/Akt signaling pathways and of miR-95 expression.

Calycosin induces apoptosis by the regulation of ERß/miR-17 signaling pathway in human colorectal cancer cells.

Prior studies have suggested that a high intake of isoflavonoids is associated with a protective effect against hormone-related cancers, such as colorectal cancer (CRC). Calycosin, a main component of isoflavones, has been shown to suppress the growth of hormone-dependent tumors through an ERß-mediated signaling pathway. However, the effects of calycosin on CRC remain unclear. In this study, we aimed to investigate the anti-tumor activities of calycosin on CRC and its potential mechanism. HCT-116 cells were treated with calycosin. Cell proliferation, apoptosis and invasiveness were measured by MTT assay, flow cytometry and transwell invasion assay, respectively. mRNA levels of ER beta (ERß) and miR-17 were quantified by real-time PCR. Protein expressions of ERß and phosphatase and tensin homolog deleted on chromosome ten (PTEN) were determined by western blotting. We found that calycosin significantly induced apoptosis, and inhibited proliferation and invasiveness of HCT-116 cells in a dose-dependent manner. In addition, ERß expression significantly increased in calycosin-treated HCT-116 cells, followed by a decrease of miR-17, and up-regulation of PTEN. Our results indicate that calycosin has an inhibitory effect on CRC, which might be obtained by ERß-mediated regulation of miR-17 and PTEN expression.

Formononetin promotes cell cycle arrest via downregulation of Akt/Cyclin D1/CDK4 in human prostate cancer cells.

BACKGROUND: Formononetin is an O-methylated isoflavone isolated from the root of Astragalus membranaceus. It has already been reported that formononetin could inhibit cell proliferation and induce cell apoptosis in several cancers, including prostate cancer. This study aimed to further investigate whether cell cycle arrest is involved in formononetin-mediated antitumor effect in human prostate cancer cells, along with the underlying molecular mechanism. METHODS: Human prostate cancer cells PC-3 and DU145 were respectively treated with various concentrations of formononetin. The inhibitory effect of formononetin on proliferation of prostate cancer cells was determined using MTT assays and flow cytometry. Next, formononetin-induced alterations in cyclin D1, CDK4 and Akt expression in PC-3 cells were detected by real-time PCR and western blot. RESULTS: Formononetin dose-dependently inhibited prostate cancer cell proliferation via the induction of cell cycle arrest at G0/G1 phase in vitro, which was more evident in PC-3 cells. Meanwhile, concomitant with reduced phosphorylation of Akt in PC-3 cells, formononetin remarkably downregulated expression levels of cyclin D1 and CDK4 in a dose-dependent manner. More interestingly, in the in vivo studies, formononetin showed a noticeable inhibition of tumor growth in recipient mice. CONCLUSION: Formononetin could exhibit inhibitory activity against human prostate cancer cells in vivo and in vitro, which is associated with G1 cell cycle arrest by inactivation of Akt/cyclin D1/CDK4. Therefore, formononetin may be used as a candidate agent for clinical treatment of prostate cancer in the future.

Design, synthesis and evaluation of highly selective pyridone-based class II MET inhibitors.

The high incidence of MET oncogene activation in human malignancies has prompted researchers to develop MET inhibitors. As part of our efforts to developing effective and safe therapeutic agents against MET-dependent tumors, a pyridone-based class II MET inhibitor, namely, 1-(4-((2-amino-3-iodopyridin-4-yl)-oxy)-3-fluorophenyl)-N-(4-fluorobenzyl)-4-methoxy-6-oxo-1,6-dihydropyridine-3-carboxamide (3s), was identified. Knowledge of the binding mode of class II MET inhibitors led to the design of new inhibitors that utilize 2-pyridone to conformationally restrain key pharmacophoric groups within the molecule. Integrated molecular docking and SAR studies resulted in the discovery of a novel class of pyridone MET inhibitors with high potency (IC50 of 0.005 µM) and efficient selectivity (>5000 fold) to VEGFR-2, c-Kit and RET kinases.

Estrogen receptor beta-mediated proliferative inhibition and apoptosis in human breast cancer by calycosin and formononetin.

BACKGROUND: Calycosin and formononetin are two main components of isoflavones. In our previous studies, we have respectively reported their antitumor activities on breast cancer cell MCF-7. To further investigate the feasibility of isoflavones in clinically treating breast carcinoma, here we specifically focused on the comparison between calycosin and formononetin, along with the relevant mechanism. METHODS: ER-positive (MCF-7, T-47D) and ER-negative breast cancer cells (MDA-231, MDA-435) were respectively treated with calycosin or formononetin. Cell proliferation and apoptosis were measured by MTT assay and flow cytometry. mRNA levels of ER beta (ERß) and miR-375 were quantifed by real-time PCR. Expression of ERß and insulin-like growth factor 1 receptor (IGF-1R), and activation of poly (ADP-ribose) polymerase 1 (PARP-1) were determined by Western blotting. RESULTS: Both calycosin and formononetin impaired proliferation and triggered apoptosis of ER-positive breast cancer cells (MCF-7, T-47D) in a time- and dose-dependent manner, especially in the treatment with calycosin. However, no such effect was observed in ER-negative breast cancer cells, indicating the correlation between isoflavones-induced inhibitory effect and ERs. Thus calycosin and most sensitive MCF-7 cells were used to study the relevant signaling pathway. After the treatment of calycosin, ERß expression was significantly increased in MCF-7 cells, followed by decrease of IGF-1R, activation of PARP-1 cleavage and downregulation of miR-375. CONCLUSION: Calycosin has an advantage on inhibiting breast cancer growth in comparison with formononetin, which is obtained by ERß-mediated regulation of IGF-1R signaling pathways and miR-375 expression.

The discovery of novel N-(2-pyrimidinylamino) benzamide derivatives as potent hedgehog signaling pathway inhibitors.

Hedgehog signaling pathway inhibitors are emerging as new therapeutic intervention against cancer. A novel series of N-(2-pyrimidinylamino) benzamide derivatives as hedgehog signaling pathway inhibitors were designed and synthesized. Most compounds presented significant inhibitory effect on hedgehog signaling pathway, among which 21 compounds exhibited more potent than vismodegib. Furthermore, compound 6a showed moderate pharmacokinetic properties in vivo, representing a promising lead compound for further exploration.