CK-3, A Novel Methsulfonyl Pyridine Derivative, Suppresses Hepatocellular Carcinoma Proliferation and Invasion by Blocking the PI3K/AKT/mTOR and MAPK/ERK Pathways.

Hepatocellular carcinoma (HCC) is an aggressive tumor with a poor prognosis that highly expresses phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (ERK). The PI3K/AKT/mTOR and MAPK/ERK signaling pathways play a crucial role in HCC tumor formation, cell cycle, apoptosis and survival. However, no effective targeted therapies against these pathways is available, mainly due to the extensive and complex negative feedback loops between them. Here we used CK-3, a dual blocker of the PI3K/AKT/mTOR and MAPK/ERK pathways, against HCC cell lines to verify its anti-tumor activity in vitro. CK-3 exhibited cytotoxic activity against HCC, as demonstrated with MTT and colony formation assays. The anti-metastatic potential of CK-3 was demonstrated with wound healing and cell invasion assays. The ability of CK-3 to block both the PI3K/AKT/mTOR and MAPK/ERK pathways was also confirmed. CK-3 induced the apoptosis of Hep3B cells, while Bel7402 cells died via mitotic catastrophe (MC). Oral administration of CK-3 also inhibited the subcutaneous growth of BEL7402 cells in nude mice. Simultaneous PI3K/AKT/mTOR and MAPK/ERK pathway inhibition with CK-3 may be superior to single pathway monotherapies by inhibiting their feedback-regulation, and represents a potential treatment for HCC.

Neuroprotective effects of kukoamine A on 6-OHDA-induced Parkinson's model through apoptosis and iron accumulation inhibition.

Objective: Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons in substantia nigra (SN). Our previous study demonstrated kukoamine A (KuA) to exhibit strong neuroprotective effects through antioxidative stress, and autophagy in MPTP/MPP+-induced PD models in vivo and in vitro. It is necessary to evaluate the efficacy of the anti-PD effects under various models. Methods: In the present study, total chemical synthesis was used to obtain KuA, which performed low content in Lycii Cortex. Then, 6-OHDA-induced PD model of PC12 cells was used to investigate the effects of KuA on PD. Results: Our results demonstrated that KuA ameliorated cell loss and mitochondrial membrane potential (MMP) loss, and inhibited Bax/Bcl-2 ratio increase that were induced by 6-OHDA. Iron accumulation in SN is thought to participate in neuronal death in PD, which subsequently resulted in oxidative stress and overexpression of α-synuclein caused by iron metabolism protein disorder. In our study, KuA could chelate cellular iron content and decrease iron influx. Moreover, KuA could upregulate the expression of ferroportin1 and Hephaestin, downregulate the expression of DMT1, TfR, and Ferritin to maintain cellular iron homeostasis avoiding neuronal death from cellular iron deposition. Moreover, KuA could decrease the expression of a-synuclein in cells. All the results indicated that KuA protected against neurotoxin-induced PD due to the apoptosis inhibition and iron homeostasis maintaining. Conclusion: KuA treatment might represent a neuroprotective treatment for PD.

The PI3Kα inhibitor DFX24 suppresses tumor growth and metastasis in non-small cell lung cancer via ERK inhibition and EPHB6 reactivation.

EPHB6 is a metastasis inhibitory gene that is frequently decreased or deficiency in non-small cell lung cancer (NSCLC), which contributed to the subsequent development of distant metastasis. These suggested the possibility that reactivation of EPHB6 might prevent the metastasis of NSCLC. Nevertheless, EPHB6 expression might also promote cancer cell growth and inhibit cell apoptosis by activating Akt and ERK pathway, apart from inhibition of migration and invasion. In the present study, we developed a novel quinazolin-4(3H)-one analog (DFX24) as a potential PI3Kα inhibitor, which inhibited both cell proliferation and metastasis of NSCLC cell lines. Investigation to the molecular mechanisms revealed DFX24 inhibited the cell growth and metastasis via inhibition of PI3Kα and ERK activity, as well as the increase in EPHB6 expression. In addition, DFX24 also induced cell cycle arrest and tumor cell apoptosis by inhibiting PI3K/Akt pathway and activating mitochondria-dependent pathway, respectively. These findings suggested that DFX24 might be considered as a novel drug candidate and may provide a potential therapy for NSCLC.

Design, synthesis and evaluation of some 1,6-disubstituted-1H-benzo[d]imidazoles derivatives targeted PI3K as anticancer agents.

Phosphatidylinositol 3-kinase (PI3K) pathway regulates various cellular processes, such as proliferation, growth, autophagy and apoptosis. Class I PI3K is frequently mutated and overexpressed in a lot of human cancers and PI3K was considered as a target for therapeutic treatment of cancer. In this study, we designed and synthesized a series of 1,6-disubstituted-1H-benzo[d]imidazoles derivatives and evaluated their anticancer activity and the compound 8i was identified as a lead compound. Compound 8i with the most potent antiproliferative activity was selected for further biological mechanism. The PI3K kinase assay have shown potent efficiency against four subtypes of PI3K with an IC50 of 0.5-1.9 nM. Molecular docking showed a possible formation of H-bonding with essential amino acid residues. Meanwhile, western blot assay indicated that 8i inhibited cell proliferation via suppression of PI3K kinase activity and subsequently blocked PI3K/Akt pathway activation in HCT116 cells. In addition, 8i could inhibit the migration and invasion ability of HCT116 cells and could induce apoptosis of HCT116 cells.

ZW290 Increases Cold Tolerance by Inducing Thermogenesis via the Upregulation of Uncoupling Protein 1 in Brown Adipose Tissue In Vitro and In Vivo.

To provide molecular evidence on the thermogenic mechanism of primary brown adipocytes, western blot analysis was used to detect brown adipose tissue (BAT)-specific gene expressions. BAT protects the mammals from hypothermia injury with a large amount of mitochondria and high expression of uncoupling Protein 1 (UCP1), which is the vital protein to determine the heat production in BAT. In our previous study, the compound ZW290 (the structure shown in Fig. 1) was obtained by molecular docking with a UCP1 inducer. In the present study, ZW290 not only significantly upregulated the expression of UCP1 protein (p < 0.01) and its related signaling pathway in the primary brown adipocytes, but also remarkably decreased the mitochondrial membrane potential and the concentration of adenosine triphosphate (ATP) (p < 0.01). Kunming (KM) mice were kept under acute cold exposure (-20°C) to evaluate the preventive and protective effects of ZW290 on cold injury, and revealed its regulating mechanism in vitro. The rectal and body temperatures of ZW290-treated mice were significantly higher than those of the control (or model) group both at room temperature and at -20°C (p < 0.001). Hematoxylin-eosin (HE) staining and immunohistochemistry indicated that ZW290 notably decreased the size of lipid droplets in BAT and increased the content of mitochondria and the expression of UCP1 in BAT and white adipose tissue (WAT). Furthermore, the survival rate showed that ZW290 could prolong the overall survival of mice. Therefore, we obtained the conclusion that ZW290 might transform energy into heat by inhibiting ATP synthesis and increasing the expression of UCP1. Additionally, ZW290 may enhance cold tolerance by increasing heat production through increasing the content of mitochondria and the expression of UCP1 in BAT and WAT.

Design, synthesis, and biological evaluation of some novel 4-aminoquinazolines as Pan-PI3K inhibitors.

A series of 4-aminoquinazolines derivatives containing hydrophilic group were designed and identified as potent Pan-PI3K inhibitors in this study. The results of antiproliferative assays in vitro showed that this series of compounds had strong inhibition of tumor growth, especially compound 7b for MCF-7 cells but weak inhibition to normal cells. PI3K kinase assay showed that 7b had high activity for three PI3K isoforms with the IC50 values of picomole. The western blot assay indicated that 7b could decrease the phospho-Akt (S473) in a dose-dependent manner. Further experiments showed that 7b could induce apoptosis in MCF-7 cells. Four key hydrogen bonding interactions were found in the docking of 7b with PI3K kinase. All these results suggested that 7b is a potent PI3K inhibitor and could be considered as a potential candidate for the development of anticancer agents.

Daurinoline suppressed the migration and invasion of chemo-resistant human non-small cell lung cancer cells by reversing EMT and Notch-1 and sensitized the cells to Taxol.

Non-small cell lung cancer (NSCLC) is one of the most common malignancies, and Taxol is a cornerstone in the treatment. However, taxol-resistance eventually limits the clinical effects and applications. Daurinoline could restore the sensitivity of resistant MCF-7/adr and KBv200 cells. Whereas, the effect of daurinoline on the chemo-resistant NSCLC cells and the mechanism has not been elucidated. In this study, daurinoline was firstly demonstrated that inhibited the proliferation, migration, invasion and EMT phenotype of chemo-resistant NSCLC cells. And these effects were associated with EMT and Notch-1 reversal. Moreover, daurinoline could significantly enhance the anti-tumor effect of Taxol rather than epirubicin, adriamycin and cisplatin. And the reverse fold (RF) value of daurinoline was greater than terfenadine reported before. There are little cytotoxic effects of daurinoline and its derivatives reported by L.W. Fu, et al. (2001). Therefore, daurinoline may be a potential anti-tumor agent or chemosensitizer for chemo-resistant NSCLC patients.

A novel inhibitor of ADAM17 sensitizes colorectal cancer cells to 5-Fluorouracil by reversing Notch and epithelial-mesenchymal transition in vitro and in vivo.

OBJECTIVES: Colorectal cancer is one of the most common malignancies both in men and women. Owing to metastasis and resistance, the prognosis of colorectal cancerCRC patients remains extremely poor with chemotherapy. A disintegrin and metalloproteinase 17 (ADAM17) induces the activation of Notch pathway and contributes to the chemoresistance. This study aimed to discover a novel ADAM17 inhibitor and investigate the chemosensitization effect. MATERIALS AND METHODS: Pharmacophore model, western blot and enzymatic assay were used to discover ZLDI-8. Cell proliferation was determined by MTT and colony formation assay. Cell migratory and invasive ability were determined by wound healing scratch and transwell assay. Immunofluorescence images and western blot analysed the expression of Notch or epithelial-mesenchymal transition (EMT) pathway markers. Xenografts were employed to evaluate the chemosensitization effect of ZLDI-8 in vivo. RESULTS: We found that ZLDI-8 cell-specifically inhibited the proliferation of CRC, and this effect was due to abrogation of ADAM17 and Notch pathway. Meanwhile, we reported for the first time that ZLDI-8 synergistically improved the anti-tumour and anti-metastasis activity of 5-fluorouracil or irinotecan by reversing Notch and EMT pathways. Interestingly, in vivo studies further demonstrated that ZLDI-8 promoted the anti-tumour effect of 5-fluorouracil through Notch and EMT reversal. CONCLUSIONS: A novel ADAM17 inhibitor ZLDI-8 may be a potential chemosensitizer which sensitized CRC cells to 5-fluorouracil or irinotecan by reversing Notch and EMT pathways.

Design, synthesis and biological evaluation of novel series of 2H-benzo[b][1,4]oxazin-3(4H)-one and 2H-benzo[b][1,4]oxazine scaffold derivatives as PI3Kα inhibitors.

The abnormal activation of PI3K signaling pathway leads to the occurrence of various cancers. The PI3Kα is frequently mutated and overexpressed in many human cancers. Therefore, the PI3Kα was considered as a promising target in therapeutic treatment of cancer. In this study, two series of compounds containing 2H-benzo[b][1,4]oxazin-3(4H)-one and 2H-benzo[b][1,4]oxazine scaffold were synthesized and evaluated antiproliferative activities against three cancer cell lines, including HCT-116, MDA-MB-231 and SNU638. Compound 7f with the most potent antiproliferative activity was selected for further evaluation on normal cells and PI3K kinase. Studies indicated that compound 7f could decrease the phospho-Akt (T308) in a dose-dependent manner. Four key hydrogen bonding interactions were found in the docking of 7f with PI3K enzyme. All the results suggested that 7f was a potent PI3Kα inhibitor.

Design, synthesis and biological evaluation of novel 4-aminoquinazolines as dual target inhibitors of EGFR-PI3Kα.

The overexpression of EGFR correlates with rapidly progressive disease, resistance to chemotherapy and poor prognosis. In certain human cancers, PI3K works synergistically with EGFR to promote proliferation, survival, invasion and metastasis. Development of dual-target drugs against EGFR and PI3K has therapeutic advantage and was an attractive approach against tumors. In this work, based on the molecular docking and previous studies, a series of 4-aminoquinazolines derivatives containing 6-sulfonamide substituted pyridyl group were rationally designed and identified as potent EGFR and PI3K dual inhibitors. The cytotoxicity experiment results showed that this series of compounds could effectively inhibit cell growth. The kinase assay demonstrated that 6c and 6i had high inhibition for EGFR and selectivity for PI3Kα distinguished from other isoforms. Further experiments showed that 6c could induce cell cycle arrest in G1 phase and apoptosis in BT549 cells. The western blot assay indicated that 6c inhibited the proliferation of BT549 cell through EGFR and PI3Kα/Akt signaling pathway. Our study suggested that compound 6c was a potential dual inhibitors of EGFR and PI3Kα.

Novel 4-aminoquinazoline derivatives induce growth inhibition, cell cycle arrest and apoptosis via PI3Kα inhibition.

Phosphatidylinositol 3-kinase (PI3K) signaling pathway has diverse functions, including the regulation of cellular survival, proliferation, cell cycle, migration, angiogenesis and apoptosis. Among class I PI3Ks (PI3Kα, ß, γ, δ), the PIK3CA gene encoding PI3K p110α is frequently mutated and overexpressed in a large portion of human cancers. Therefore, the inhibition of PI3Kα has been considered as a promising target for the development of a therapeutic treatment of cancer. In this study, we designed and synthesized a series of 4-aminoquinazoline derivatives and evaluated their antiproliferative activities against six cancer cell lines, including HCT-116, SK-HEP-1, MDA-MB-231, SNU638, A549 and MCF-7. Compound 6b with the most potent antiproliferative activity and without obvious cytotoxicity to human normal cells was selected for further biological evaluation. PI3K kinase assay showed that 6b has selectivity for PI3Kα distinguished from other isoforms. The western blot assay and PI3K kinase assay indicated that 6b effectively inhibited cell proliferation via suppression of PI3Kα kinase activity with an IC50 of 13.6 nM and subsequently blocked PI3K/Akt pathway activation in HCT116 cells. In addition, 6b caused G1 cell cycle arrest owing to the inhibition of PI3K signaling and induced apoptosis via mitochondrial dependent apoptotic pathway. Our findings suggested that 6b has a therapeutic value as an anticancer agent via PI3Kα inhibition.

Design, synthesis, and biological evaluation of novel 3-substituted imidazo[1,2-a]pyridine and quinazolin-4(3H)-one derivatives as PI3Kα inhibitors.

Phosphatidylinositol 3-kinase (PI3K) is a pivotal regulator of intracellular signaling pathways and considered as a promising target in the development of a therapeutic treatment of cancer. Among the different PI3K subtypes, the PIK3CA gene encoding PI3K p110α is frequently mutated and overexpressed in majority of human cancers. Therefore, the inhibition of PI3Kα has been considered to be an efficient approach for the treatment of cancer. In this study, two series compounds containing hydrophilic group in imidazo[1,2-a]pyridine and quinazolin-4(3H)-one were synthesized and their antiproliferative activities against five cancer cell lines, including HCT-116, SK-HEP-1, MDA-MB-231, SNU638 and A549, were evaluated. Compound 1i with most potent antiproliferative activity was selected for further biological evaluation. PI3K kinase assay showed that 1i has selectivity for PI3Kα distinguished from other isoforms. The western blot assay indicated that 1i is more effective than HS-173, an imidazopyridine-based PI3Ka inhibitor, in reducing the levels of phospho-Akt. All these results suggested that 1i is a potent PI3Kα inhibitor and could be considered as a potential candidate for the development of anticancer agents.