Synthesis and biological activities of novel mitochondria-targeted artemisinin ester derivatives

A mitochondria-targeting dihydroartemisinin derivative as a reactive oxygen species -based immunogenic cell death inducer

Immunogenic cell death (ICD) can activate the anticancer immune response and its occurrence requires high reliance on oxidative stress. Inducing mitochondrial reactive oxygen species (ROS) is a desirable capability for ICD inducers. However, in the category of ICD-associated drugs, numerous reported ICD inducers are a series of anthracyclines and weak in ICD induction. Herein, a mitochondria-targeting dihydroartemisinin derivative (T-D) was synthesized by conjugating triphenylphosphonium (TPP) to dihydroartemisinin (DHA). T-D can selectively accumulate in mitochondria to trigger ROS generation, leading to the loss of mitochondrial membrane potential (ΔΨm) and ER stress. Notably, T-D exhibits far more potent ICD-inducing properties than its parent compound. In vivo, T-D-treated breast cancer cell vaccine inhibits metastasis to the lungs and tumor growth. These results indicate that T-D is an excellent ROS-based ICD inducer with the specific function of trigging vigorous ROS in mitochondria and sets an example for incorporating artemisinin-based drugs into the ICD field.

A comprehensive overview of Artemisinin and its derivatives as anticancer agents

Artemisinin is the crucial ingredient of artemisia annua, a traditional Chinese medicine used for the therapy of malaria in China for hundreds of years. In recent years, the anticancer properties of artemisinin and its derivatives have also been reported. This review has summarized the research and development of artemisinin and its derivatives as anticancer agents, which included both natural and synthetic monomers as well as their dimers. In addition, it highlights the antitumor effects of artemisinin and its derivatives after site-modification or after transformation to a nano-delivery system. Moreover, we have further explored their potential mechanisms of action and also discussed the clinical trials of ARTs used to treat cancer, which will facilitate in further development of novel anticancer drugs based on the scaffold of artemisinin.

Identification of Novel Artemisinin Hybrids Induce Apoptosis and Ferroptosis in MCF-7 Cells

A series of novel 1,3,4-oxadiazole-artemisinin hybrids have been designed and synthesized. An MTT assay revealed that most of tested hybrids showed more enhanced anti-proliferative activities than artemisinin, among which A8 had the superior potency with IC₅₀ values ranging from 4.07 μM to 9.71 μM against five tested cancer cell lines. Cell colony formation assays showed that A8 could inhibit significantly more cell proliferation than artemisinin and 5-fluorouracil. Further mechanism studies reveal that A8 induces apoptosis and ferroptosis in MCF-7 cells in a dose-dependent manner, and CYPs inhibition assays reveal that A8 has a moderate inhibitory effect on CYP1A2 and CYP3A4 in the human body at 10 μM. The present work indicates that hybrid A8 may merit further investigation as a potential therapeutic agent.

Synthesis and Antitumor Activities of Novel Mitochondria-Targeted Dihydroartemisinin Ether Derivatives

Ten novel mitochondria-targeted dihydroartemisinin ether derivatives were designed, synthesized, and evaluated for antitumor activity against five cancer cell lines in vitro. Profoundly, compound D8-T (IC₅₀ = 56.9 nM) showed the most potent antiproliferative activity against the T24 cells with low cytotoxicity in normal human umbilical vein endothelial cells. High-performance liquid chromatography analysis confirmed that D8-T targeted mitochondria 6.3-fold higher than DHA. ATP content assay demonstrated that D8-T decreased the ATP level of bladder cancer cells. The effect of D8-T on cell apoptosis was determined by flow cytometry and western blot of Bax and Bcl-2. Surprisingly, the results indicated that D8-T did not induce bladder cancer cell apoptosis. In contrast, the cell cycle analysis and western blot of CDK4, CDK6, cyclin D1, and p21 demonstrated that the cancer cell cycle was arrested at the G1 phase after D8-T treatment. Furthermore, the consistent results were received by RNA-seq assay. These promising findings implied that D8-T could serve as a great candidate against bladder cancer for further investigation.

Development of artesunate intelligent prodrug liposomes based on mitochondrial targeting strategy

Breast cancer is the leading cause of cancer-related deaths in women and remains a formidable therapeutic challenge. Mitochondria participate in a myriad of essential cellular processes, such as metabolism, and are becoming an ideal target for cancer therapy. Artemisinin and its derivatives have demonstrated multiple activities in the context of various cancers. Mitochondrial autophagy(mitophagy) is one of the important anti-tumor mechanisms of artemisinin drugs. However, the lack of specific tumor targeting ability limits the anti-tumor efficacy of artemisinin drugs. In this study, a GSH-sensitive artesunate smart conjugate (TPP-SS-ATS) was synthesized and liposomes (TPP-SS-ATS-LS) that target tumor cells and mitochondria were further prepared. The advantages of TPP-SS-ATS-LS targeting to the breast tumor were verified by in vivo and in vitro evaluations. In our study, the cytotoxicity was obviously enhanced in vitro and tumor growth inhibition rate was increased from 37.7% to 56.4% at equivalent artesunate dosage in breast cancer orthotopic implanted mice. Meanwhile, mitochondrial dysfunction, suppression of ATP production and respiratory capacity were detected in breast cancer cells. We further discovered that TPP-SS-ATS-LS inhibited tumor cells proliferation through mitophagy by regulating PHB2 and PINK1 expression_. These results provide new research strategies for the development of new artemisinin-based anti-tumor drugs.

Novel dihydroartemisinin derivative Mito-DHA5 induces apoptosis associated with mitochondrial pathway in bladder cancer cells

Background

Bladder cancer is the second most common genitourinary malignancy and the eleventh most common cancer worldwide. Dihydroartemisinin (DHA), a first-line antimalarial drug, has been found to have potent antitumor activity. In our previous study, a novel dihydroartemisinin derivative Mito-DHA₅ synthesized in our laboratory has a stronger anti-tumor activity than DHA. In this study, we investigated the apoptotic effect of Mito-DHA₅ on bladder cancer T24 cells and molecular mechanisms underlying.

Methods

Antitumor activity in vitro was evaluated by MTT, wound healing and cloning formation assays. Mitochondrial membrane potential (MMP) was detected by JC-1 probe and ROS levels were measured by specific kit. The expression of caspase-3, cleaved-caspase3, mitochondrial Cyt-C, Bcl-2, Bax and PARP in T24 cells was evaluated by Western blotting.

Results

The results showed that Mito-DHA₅ reduced cell viability with an IC₅₀ value of 3.2 µM and induced T24 cell apoptosis in a dose-dependent manner, increased the production of ROS and decreased MMP. Mito-DHA₅ could down-regulate the expression of Bcl-2, mitochondrial Cyt-C, Caspase-3, PARP and up-regulate the expression of Bax and cleaved Caspase-3.

Conclusions

These data suggested that Mito-DHA₅ had a potent inhibitory effect on T24 bladder cancer cell growth and induced these cells apoptosis associated with mitochondrial pathway.