2-(Naphthalene-1-yl)-6-pyrrolidinyl-4-quinazolinone inhibits skin cancer M21 cell proliferation through aberrant expression of microtubules and the cell cycle

Far-Red Light-Activatable Prodrug of Paclitaxel for the Combined Effects of Photodynamic Therapy and Site-Specific Paclitaxel Chemotherapy

Paclitaxel (PTX) is one of the most useful chemotherapeutic agents approved for several cancers, including ovarian, breast, pancreatic, and nonsmall cell lung cancer. However, it causes systemic side effects when administered parenterally. Photodynamic therapy (PDT) is a new strategy for treating local cancers using light and photosensitizer. Unfortunately, PDT is often followed by recurrence due to incomplete ablation of tumors. To overcome these problems, we prepared the far-red light-activatable prodrug of PTX by conjugating photosensitizer via singlet oxygen-cleavable aminoacrylate linker. Tubulin polymerization enhancement and cytotoxicity of prodrugs were dramatically reduced. However, once illuminated with far-red light, the prodrug effectively killed SKOV-3 ovarian cancer cells through the combined effects of PDT and locally released PTX. Ours is the first PTX prodrug that can be activated by singlet oxygen using tissue penetrable and clinically useful far-red light, which kills the cancer cells through the combined effects of PDT and site-specific PTX chemotherapy.

Molecular modelling, synthesis, cytotoxicity and anti-tumour mechanisms of 2-aryl-6-substituted quinazolinones as dual-targeted anti-cancer agents

BACKGROUND AND PURPOSE

Our previous study demonstrated that 6-(pyrrolidin-1-yl)-2-(3-methoxyphenyl)quinazolin-4-one (HMJ38) was a potent anti-tubulin agent. Here, HMJ38 was used as a lead compound to develop more potent anti-cancer agents and to examine the anti-cancer mechanisms.

EXPERIMENTAL APPROACH

Using computer-aided drug design, 2-aryl-6-substituted quinazolinones (MJ compounds) were designed and synthesized by introducing substituents at C-2 and C-6 positions of HMJ38. The cytotoxicity of MJ compounds towards human cancer cells was examined by Trypan blue exclusion assay. Microtubule distribution was visualized using TubulinTracker(TM) Green reagent. Protein expression of cell cycle regulators and JNK was assessed by Western blot analysis.

KEY RESULTS

Compounds MJ65-70 exhibited strong anti-proliferative effects towards melanoma M21, lung squamous carcinoma CH27, lung non-small carcinoma H460, hepatoma Hep3B and oral cancer HSC-3 cells, with one compund MJ66 (6-(pyrrolidin-1-yl)-2-(naphthalen-1-yl)quinazolin-4-one) highly active against M21 cells (IC50 about 0.033 μM). Treatment of CH27 or HSC-3 cells with MJ65-70 resulted in significant mitotic arrest accompanied by increasing multiple asters of microtubules. JNK protein expression was involved in the MJ65-70-induced CH27 and M21 cell death. Consistent with the cell cycle arrest at G2/M phase, marked increases in cyclin B1 and Bcl-2 phosphorylation were also observed, after treatment with MJ65-70.

CONCLUSIONS AND IMPLICATION

MJ65-70 are dual-targeted, tubulin- and JNK-binding, anti-cancer agents and induce cancer cell death through up-regulation of JNK and interfering in the dynamics of tubulin. Our work provides a new strategy and mechanism for developing dual-targeted anti-cancer drugs, contributing to clinical anti-cancer drug discovery and application.

MJ-66 induces malignant glioma cells G2/M phase arrest and mitotic catastrophe through regulation of cyclin B1/Cdk1 complex

Malignant gliomas are among the most devastating cancers as they are resistant to many kinds of treatment. Despite recent advances in the diagnosis and treatment, the prognosis of patients remains very poor and the development of new drug is urgently needed. Here, we report that a synthetic quinazolinone analog 2-(naphthalene-1-yl)-6-pyrrolidinyl-4-quinazolinone (MJ-66) induced glioma cell death. Immunofluorescence staining showed that MJ-66-induced cell death was associated with multinucleated phenotype and multipolar spindles that were typical characteristics of mitotic catastrophe. Flow cytometry analysis revealed that MJ-66 caused glioma cell cycle arrest at G2/M phase and increased the proportion of polyploidy cells. Western blotting indicated that the expression of cyclin B1, Cdk1 pY15 and Cdk1 increased after treatment with MJ-66. MJ-66 effectively inhibited tumor growth and induced apoptosis in the xenograft animal model of U87 human glioma cells. Together, these results suggest that MJ-66 inhibited malignant gliomas growth through inducing mitotic catastrophe by interference with G2/M cell cycle checkpoint which may open a new avenue for the treatment of malignant gliomas.

Dual inhibition of EGFR and c-Met kinase activation by MJ-56 reduces metastasis of HT29 human colorectal cancer cells

Quinazolinone derivatives are known to possess anticancer activities on cell metastasis and cell death in different human cancer cell lines. Here, we studied the anti-metastasis activity and the underlying mechanisms of the novel quinazoline derivative MJ-56 (6-pyrrolidinyl-2-(3-bromostyryl)quinazolin-4-one). MJ-56 inhibited cell migration and invasion of HT29 human colorectal cancer cells by wound-healing and Matrigel-coated transwell assays in a concentration-dependent manner. MJ-56-treated cells resulted in the reduced expression of matrix metalloproteinase (MMP)-2, -7, -9 and -10 and the reduced enzymatic activities of MMP-2 and MMP-9. In contrast, MJ-56-treated cells enhanced the expression of the tissue inhibitors of metalloproteinases (TIMPs) TIMP-1 and TIMP-2. Further analyses showed that MJ-56 attenuated the activities of epidermal growth factor receptor (EGFR), c-Met and the downstream ERK-mediated MAPK and PI3K/AKT/mTOR signaling pathways, which led to decreased protein synthesis by dephosphorylating the translation initiation factors eIF-4B, eIF-4E, eIF-4G and S6 ribosomal protein. In addition, MJ-56 interfered with the NF-κB signaling via impairing PI3K/AKT activation and subsequently reduced the NF-κB-mediated transcription of MMPs. Taken together, the reduced expression of phosphor-EGFR and c-MET is chiefly responsible for all events of blocking metastasis. Our results suggest a potential role of MJ-56 on therapy of colorectal cancer metastasis.