Editorial: Unravelling Copper-Regulatory Systems and Copper-Affected Pathways in Cancer Cells to Improve Current Therapies

Unravelling Copper-Regulatory Systems and Copper-Affected Pathways in Cancer Cells to Improve Current Therapie

Methods for preventing and treating cancer using N-thiolated β-lactam compounds and analogs thereof

The subject invention concerns N-thiolated β-lactam compounds of formula A, wherein R1 is a hydrocarbon group having 1–8 carbon atoms; R3 is an organothio group; and R4 is alkyl, alkenyl, alkynyl, aryl, heteroaryl, cycloalkyl, heterocycloalkyl, cycloalkenyl, or heterocycloalkenyl, and analogs and pharmaceutically acceptable salts, esters and amides thereof. The subject invention also concerns methods for inducing tumor cell death or inhibiting tumor cell proliferation, and methods for inducing DNA damage, inhibiting DNA replication, activating p38 MAP kinase, or activating caspase cascade activation, or releasing cytochrome C from mitochondria into the cytoplasm in a tumor cell. Methods for treating cancer using N-thiolated β-lactam compounds, as well as pharmaceutical compositions comprising the same are further disclosed

Use of proteasome inhibitors in anticancer therapy

The importance of the ubiquitin-proteasome pathway to cellular function has brought it to the forefront in the search for new anticancer therapies. The ubiquitin-proteasome pathway has proven promising in targeting various human cancers. The approval of the proteasome inhibitor bortezomib for clinical treatment of relapsed/refractory multiple myeloma and mantle cell lymphoma has validated the ubiquitin-proteasome as a rational target. Bortezomib has shown positive results in clinical use but some toxicity and side effects, as well as resistance, have been observed, indicating that further development of novel, less toxic drugs is necessary. Because less toxic drugs are necessary and drug development can be expensive and time-consuming, using existing drugs that can target the ubiquitin-proteasome pathway in new applications, such as cancer therapy, may be effective in expediting the regulatory process and bringing new drugs to the clinic. Toward this goal, previously approved drugs, such as disulfiram, as well as natural compounds found in common foods, such as green tea polyphenol (-)-EGCG and the flavonoid apigenin, have been investigated for their possible proteasome inhibitory and cell death inducing abilities. These compounds proved quite promising in preclinical studies and have now moved into clinical trials, with preliminary results that are encouraging. In addition to targeting the catalytic activity of the proteasome pathway, upstream regulators, such as the 19S regulatory cap, as well as E1, E2, and E3, are now being investigated as potential drug targets. This review outlines the development of novel proteasome inhibitors from preclinical to clinical studies, highlighting their abilities to inhibit the tumor proteasome and induce apoptosis in several human cancers

Polyphenol proteasome inhibitors, synthesis, and methods of use

The present invention relates to synthetic green tea derived polyphenolic compounds, their modes of syntheses, and their use in inhibiting proteasomal activity and in treating cancers. The present invention is also directed to pharmaceutical compositions useful in methods of inhibiting proteasomes and of treating cancers

Gold(III)-Dithiocarbamato Peptidomimetics in the Forefront of the Targeted Anticancer Therapy: Preclinical Studies against Human Breast Neoplasia

Since the serendipitous discovery of cisplatin, platinum-based drugs have become well-established antitumor agents, despite the fact that their clinical use is limited by many severe side-effects. In order to both improve the chemotherapeutic index and broaden the therapeutic spectrum of current drugs, our most recent anti-neoplastic agents, Au(III) complexes, were designed as carrier-mediated delivery systems exploiting peptide transporters, which are up-regulated in some cancers. Among all, we focused on two compounds and tested them on human MDA-MB-231 (resistant to cisplatin) breast cancer cell cultures and xenografts, discovering the proteasome as a major target both in vitro and in vivo. 53% inhibition of breast tumor growth in mice was observed after 27 days of treatment at 1.0 mg kgSUP−1 dSUP−1, compared to control. Remarkably, if only the most responsive mice are taken into account, 85% growth inhibition, with some animals showing tumor shrinkage, was observed after 13 days. These results led us to file an international patent, recognizing this class of gold(III) peptidomimetics as suitable candidates for entering phase I clinical trials

Activation of AMP-Activated Protein Kinase by 3,39-Diindolylmethane (DIM) Is Associated with Human Prostate Cancer Cell Death \u3cem\u3eIn Vitro\u3c/em\u3e and \u3cem\u3eIn Vivo\u3c/em\u3e

There is a large body of scientific evidence suggesting that 3,39-Diindolylmethane (DIM), a compound derived from the digestion of indole-3-carbinol, which is abundant in cruciferous vegetables, harbors anti-tumor activity in vitro and in vivo. Accumulating evidence suggests that AMP-activated protein kinase (AMPK) plays an essential role in cellular energy homeostasis and tumor development and that targeting AMPK may be a promising therapeutic option for cancer treatment in the clinic. We previously reported that a formulated DIM (BR-DIM; hereafter referred as B-DIM) with higher bioavailability was able to induce apoptosis and inhibit cell growth, angiogenesis, and invasion of prostate cancer cells. However, the precise molecular mechanism(s) for the anti-cancer effects of B-DIM have not been fully elucidated. In the present study, we investigated whether AMP-activated protein kinase (AMPK) is a molecular target of B-DIM in human prostate cancer cells. Our results showed, for the first time, that B-DIM could activate the AMPK signaling pathway, associated with suppression of the mammalian target of rapamycin (mTOR), down-regulation of androgen receptor (AR) expression, and induction of apoptosis in both androgen-sensitive LNCaP and androgen-insensitive C4-2B prostate cancer cells. B-DIM also activates AMPK and down-regulates AR in androgen-independent C4-2B prostate tumor xenografts in SCID mice. These results suggest that B-DIM could be used as a potential anti-cancer agent in the clinic for prevention and/or treatment of prostate cancer regardless of androgen responsiveness, although functional AR may be required

Fujiki

ABSTRACT Prostate cancer cells demonstrate slow growth kinetics and chemoresistance. Tea polyphenols have been shown to exert prostate cancer-preventative effects. Here we report that growth-arrested prostate cancer cells expressed high levels of a hyperphosphorylated Bcl-X L in mitochondria. Treatment with tea polyphenols or the major tea component epigallocatechin-3-gallate blocked expression of the hyper-, but not hypophosphorylated Bcl-X L in mitochondria, accompanied by cytochrome c release, caspase activation, and apoptosis. Studies using specific inhibitors suggest that tea inhibits p38 mitogenactivated protein kinase and the proteasome activities, leading to inhibition of Bcl-X L phosphorylation and induction of prostate cancer cell death. Epidemiological and animal studies have demonstrated the cancer preventative properties of green tea polyphenols (GTP) (Liao et a

The Proteasome Is a Molecular Target of Environmental Toxic Organotins

BACKGROUND: Because of the vital importance of the proteasome pathway, chemicals affecting proteasome activity could disrupt essential cellular processes. Although the toxicity of organotins to both invertebrates and vertebrates is well known, the essential cellular target of organotins has not been well identified. We hypothesize that the proteasome is a molecular target of environmental toxic organotins. OBJECTIVES: Our goal was to test the above hypothesis by investigating whether organotins could inhibit the activity of purified and cellular proteasomes and, if so, the involved molecular mechanisms and downstream, events. RESULTS: We found that some toxic organotins [e.g., triphenyltin (TPT)] can potently and preferentially inhibit the chymotrypsin-like activity of purified 20S proteasomes and human breast cancer cellular 26S proteasomes. Direct binding of tin atoms to cellular proteasomes is responsible for the observed irreversible inhibition. Inhibition of cellular proteasomes by TPT in several human cell lines results in the accumulation of ubiquitinated proteins and natural proteasome target proteins, accompanied by induction of cell death. CONCLUSIONS: The proteasome is one of the molecular targets of environmental toxic organotins in human cells, and proteasome inhibition by organotins contributes to their cellular toxicity

The Clinical and Theranostic Values of Activated Leukocyte Cell Adhesion Molecule (ALCAM)/CD166 in Human Solid Cancers

Activated leukocyte cell adhesion molecule (ALCAM), also known as CD166, is a cell adhesion protein that is found in multiple cell types. ALCAM has multiple and diverse roles in various physiological and pathological conditions, including inflammation and cancer. There has been compelling evidence of ALCAM’s prognostic value in solid cancers, indicating that it is a potential therapeutic target. The present article overviews the recent findings and progress in ALCAM and its involvement in cancer, with a primary focus on its clinical connections in cancer and therapeutic values

Recent advances in repurposing disulfiram and disulfiram derivatives as copper-dependent anticancer agents

© 2021 The Authors. Published by Frontiers Media. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3389/fmolb.2021.741316Copper (Cu) plays a pivotal role in cancer progression by acting as a co-factor that regulates the activity of many enzymes and structural proteins in cancer cells. Therefore, Cu-based complexes have been investigated as novel anticancer metallodrugs and are considered as a complementary strategy for currently used platinum agents with undesirable general toxicity. Due to the high failure rate and increased cost of new drugs, there is a global drive towards the repositioning of known drugs for cancer treatment in recent years. Disulfiram (DSF) is a first-line antialcoholism drug used in clinics for more than 65 yr. In combination with Cu, it has shown great potential as an anticancer drug by targeting a wide range of cancers. The reaction between DSF and Cu ions forms a copper diethyldithiocarbamate complex (Cu(DDC)2 also known as CuET) which is the active, potent anticancer ingredient through inhibition of NF-κB and ubiquitin-proteasome system as well as alteration of the intracellular reactive oxygen species (ROS). Importantly, DSF/Cu inhibits several molecular targets related to drug resistance, stemness, angiogenesis and metastasis and is thus considered as a novel strategy for overcoming tumour recurrence and relapse in patients. Despite its excellent anticancer efficacy, DSF has proven unsuccessful in several cancer clinical trials. This is likely due to the poor stability, rapid metabolism and/or short plasma half-life of the currently used oral version of DSF and the inability to form Cu(DDC)2 at relevant concentrations in tumour tissues. Here, we summarize the scientific rationale, molecular targets, and mechanisms of action of DSF/Cu in cancer cells and the outcomes of oral DSF ± Cu in cancer clinical trials. We will focus on the novel insights on harnessing the immune system and hypoxic microenvironment using DSF/Cu complex and discuss the emerging delivery strategies that can overcome the shortcomings of DSF-based anticancer therapies and provide opportunities for translation of DSF/Cu or its Cu(DDC)2 complex into cancer therapeutics.Published versio