Cytotoxicity and ROS production of novel Pt(IV) oxaliplatin derivatives with indole propionic acid

DNA Damage Repair in Glioblastoma: A Novel Approach to Combat Drug Resistance

Due to the lack of effective therapeutic approach, glioblastoma (GBM) remains one of the most malignant brain tumour. By in vitro investigations on primary GBM stem cells, we highlighted one of the underlying mechanisms of drug resistance to alkylating agents, the DNA damage responses. Here, flow cytometric analysis and viability and repopulation assays were used to assess the long-term cytotoxic effect induced by the administration of a fourth-generation platinum prodrug, the (OC-6-44)-acetatodiamminedichlorido(2-(2-propynyl)octanoato) platinum(IV) named Pt(IV)Ac-POA, in comparison to the most widely used Cisplatin. The immunofluorescence studies revealed changing pathways involved in the DNA damage response mechanisms in response to the two chemotherapies, suggesting in particular the role of Poly (ADP-Ribose) polymerases in the onset of resistance to Cisplatin-induced cytotoxicity. Thus, this research provides a proof of concept for how the use of a prodrug which allows the co-administration of Cisplatin and an Histone DeACetylase inhibitors, could suppress DNA repair mechanisms, suggesting a novel effective approach in GBM treatment.

Hollow Copper Sulfide Nanocubes Loaded with Pt(IV) Complexes for Cancer Multimodal Therapy

Chemotherapy (CT) can significantly inhibit tumor growth, metastasis, and recurrence during cancer therapy. People have widely used platinum drugs in cancer treatment. However, as most chemotherapeutic drugs, platinum drugs still have shortcomings such as poor solubility, low cell uptake, nonspecific distribution, multidrug resistance, and adverse side effects. Therefore, we synthesized hollow copper sulfide (CuS) nanocubes with photothermal and photodynamic properties as carriers for Pt(IV) drugs. Hollow CuS nanocubes have attracted considerable interest in the field of cancer photothermal therapy (PTT) using multiple biological windows. Under near-infrared (NIR) laser irradiation, Cu2+ can be reduced into Cu+ in the presence of hydrogen peroxide in the tumor microenvironment. The resulting Cu+ can be used for photodynamic therapy (PDT), which can perform a Fenton-like reaction under acidic conditions (pH 5.5-6.5) and catalyze hydrogen peroxide to produce ·OH in the tumor microenvironment. In addition, compared with Pt(II) drugs, Pt(IV) drugs not only have lower systemic toxicity but also consume glutathione (GSH), thereby increasing reactive oxygen species (ROS) levels in tumor cells and effectively promoting PDT. In this study, we oxidized ethylenediamine platinum chloride to its tetravalent state, loaded the Pt(IV) complexes using hollow CuS nanocubes, and modified the surfaces of the nanoparticles with PEG to improve the EPR effect. The Pt(IV)-loaded hollow CuS nanocubes modified with PEG (Pt(IV)-CuS@PEG) are expected to be used for tumor chemo/photothermal/photodynamic therapy.

Jones A, Romero-Canelon I, Erxleben A. Multiaction Pt(IV) Complexes: Cytotoxicity in Ovarian Cancer Cell Lines and Mechanistic Studies

Ovarian cancer has the worst case-to-fatality ratio of all gynecologic malignancies. The main reasons for the high mortality rate are relapse and the development of chemoresistance. In this paper, the cytotoxic activity of two new multiaction platinum(IV) derivatives of cisplatin and oxaliplatin in a panel of ovarian cancer cells is reported. Cis,cis,trans-[Pt(NH3)2Cl2(IPA)(DCA)] (1) and trans-[Pt(DACH)(OX)(IPA)(DCA)] (2) (IPA = indole-3-propionic acid, DCA = dichloroacetate, DACH = 1R,2R-1,2-diaminocyclohexane, OX = oxalate) were synthesized and characterized by elemental analysis, ESI-MS, FT-IR, and 1H, 13C, and195Pt NMR spectroscopy. The biological activity was evaluated in A2780, PEA1, PEA2, SKOV3, SW626, and OVCAR3 cells. Both complexes are potent cytotoxins. Remarkably, complex 2 is 14 times more active in OVCAR3 cells than cisplatin and is able to overcome cisplatin resistance in PEA2 and A2780cis cells, which are models of post-treatment patient-developed and laboratory-induced resistance. This complex also shows activity in 3D cancer models of the A2780 cells. Mechanistic studies revealed that the complexes induce apoptosis via DNA damage and ROS generation.

Pt(IV) Complexes in the Search for Novel Platinum Prodrugs with Promising Activity

The kinetically inert, six coordinated, octahedral Pt(IV) complexes are termed dual-, triple-, or multi-action prodrugs based on the nature of the axially substituted ligands. These ligands are either inert or biologically active, where the nature of these axial ligands provides additional stability, synergistic biological activity or cell-targeting ability. There are many literature reports from each of these classes, mentioning the varied nature of these axial ligands. The ligands comprise drug molecules such as chlorambucil, doxorubicin, valproic acid, ethacrynic acid, biologically active chalcone, coumarin, combretastatin, non-steroidal anti-inflammatory drugs (NSAIDs) and many more, potentiating the anti-proliferative profile or reducing the side effects associated with cisplatin therapy. The targeting and non-targeting nature of these moieties exert additive or synergistic effects on the anti-cancer activity of Pt(II) moieties. Herein, we discuss the effects of these axially oriented ligands and the changes in the non-leaving am(m)ine groups and in the leaving groups on the biological activity. In this review, we have presented the latest developments in the field of Pt(IV) complexes that display promising activity with a reduced resistance profile. We have discussed the structure activity relationship (SAR) and the effects of the ligands on the biological activity of Pt(IV) complexes with cisplatin, oxaliplatin, carboplatin and the Pt core other than approved drugs. This literature work will help researchers to get an idea about Pt(IV) complexes that have been classified based on the aspects of their biological activity.

Pyrenebutyrate Pt(IV) Complexes with Nanomolar Anticancer Activity

Research on platinum-based anticancer drugs continuously strives to develop new non-classical platinum complexes. Pt(IV) prodrugs are the most promising, and their activation-by-reduction mechanism of action is being explored as a prospect for higher selectivity and efficiency. Herein, we present the anticancer potency and chemical reactivity of Pt(IV) complexes formed by linking pyrene butyric acid with cisplatin. The results from cytotoxicity screening on 10 types of cancer cell lines and non-malignant cells (HEK-293) indicated IC50 values as low as 50-70 nM for the monosubstituted Pt(IV) complex against leukemia cell lines (HL-60 and SKW3) and a cisplatin-resistant derivative (HL-60/CDDP). Interestingly, the bis-substituted complex is virtually non-toxic to both healthy and cancerous cells of adherent types. Nevertheless, it shows high cytotoxicity against multidrug-resistant derivatives HL-60/CDDP and HL-60/Dox. The reactivity of the complexes with biological reductants was monitored by the NMR method. Furthermore, the platinum uptake by the treated cells was examined on two types of cellular cultures: adherent and suspension growing, and proteome profiling was conducted to track expression changes of key apoptosis-related proteins in HL-60 cells. The general conclusion points to a possible cytoskeletal entrapment of the bulkier bis-pyrene complex that could be limiting its cytotoxicity to adherent cells, both cancerous and healthy ones.

Molecular Pathogenesis of Colorectal Cancer with an Emphasis on Recent Advances in Biomarkers, as Well as Nanotechnology-Based Diagnostic and Therapeutic Approaches

Colorectal cancer (CRC) is a serious disease that affects millions of people throughout the world, despite considerable advances in therapy. The formation of colorectal adenomas and invasive adenocarcinomas is the consequence of a succession of genetic and epigenetic changes in the normal colonic epithelium. Genetic and epigenetic processes associated with the onset, development, and metastasis of sporadic CRC have been studied in depth, resulting in identifying biomarkers that might be used to predict behaviour and prognosis beyond staging and influence therapeutic options. A novel biomarker, or a group of biomarkers, must be discovered in order to build an accurate and clinically useful test that may be used as an alternative to conventional methods for the early detection of CRC and to identify prospective new therapeutic intervention targets. To minimise the mortality burden of colorectal cancer, new screening methods with higher accuracy and nano-based diagnostic precision are needed. Cytotoxic medication has negative side effects and is restricted by medication resistance. One of the most promising cancer treatment techniques is the use of nano-based carrier system as a medication delivery mechanism. To deliver cytotoxic medicines, targeted nanoparticles might take advantage of differently expressed molecules on the surface of cancer cells. The use of different compounds as ligands on the surface of nanoparticles to interact with cancer cells, enabling the efficient delivery of antitumor medicines. Formulations based on nanoparticles might aid in early cancer diagnosis and help to overcome the limitations of traditional treatments, including low water solubility, nonspecific biodistribution, and restricted bioavailability. This article addresses about the molecular pathogenesis of CRC and highlights about biomarkers. It also provides conceptual knowledge of nanotechnology-based diagnostic techniques and therapeutic approaches for malignant colorectal cancer.

Long-acting response of COX-2-mediated metastasis inhibition by oxaliplatin-based CP-L-OHP

Among four oxaliplatin-based Pt(iv) complexes, CP-L-OHP significantly delayed BGC-823 cell metastasis via long-acting inhibition of COX-2.

Novel Pt(IV) Prodrugs Displaying Antimitochondrial Effects

The design, synthesis, characterization, and biological activity of a series of platinum(IV) prodrugs containing the axial ligand 3-(4-phenylquinazoline-2-carboxamido)propanoate (L3) are reported. L3 is a derivative of the quinazolinecarboxamide class of ligands that binds to the translocator protein (TSPO) at the outer mitochondrial membrane. The cytotoxicities of cis,cis,trans-[Pt(NH₃)₂Cl₂(L3)(OH)] (C-Pt1), cis,cis,trans-[Pt(NH₃)₂Cl₂(L3)(BZ)] (C-Pt2), trans-[Pt(DACH)(OX)(L3)(OH)] (C-Pt3), and trans-[Pt(DACH)(OX)(L3)(BZ)] (C-Pt4) (DACH: R,R-diaminocyclohexane, BZ: benzoate, OX: oxalate) in MCF-7 breast cancer and noncancerous MCF-10A epithelial cells were assessed and compared with those of cisplatin, oxaliplatin, and the free ligand L3. Moreover, the cellular uptake, ROS generation, DNA damage, and the effect on the mitochondrial function, mitochondrial membrane potential, and morphology were investigated. Molecular interactions of L3 in the TSPO binding site were studied using molecular docking. The results showed that complex C-Pt1 is the most effective Pt(IV) complex and exerts a multimodal mechanism involving DNA damage, potent ROS production, loss of the mitochondrial membrane potential, and mitochondrial damage.

Current scenario of indole derivatives with potential anti-drug-resistant cancer activity

Cancer chemotherapy is frequently hampered by drug resistance, so the resistance to anticancer agents represents one of the major obstacles for the effective cancer treatment. Indole derivatives have the potential to act on diverse targets in cancer cells and exhibit promising activity against drug-resistant cancers. Moreover, some indole-containing compounds such as Semaxanib, Sunitinib, Vinorelbine, and Vinblastine have already been applied in clinics for various kinds of cancer even drug-resistant cancer therapy. Thus, indole derivatives are one of significant resources for the development of novel anti-drug-resistant cancer agents. This review focuses on the recent development of indole derivatives with potential therapeutic application for drug-resistant cancers, and the mechanisms of action, the critical aspects of design as well as structure-activity relationships, covering articles published from 2010 to 2020.