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The development of novel anticancer drugs with antiproliferative and antimetastatic activities is of great importance in the pharmaceutical field. Herein, a series of ligustrazine (LSZ) platinum(IV) complexes with chemotherapeutic and immunotherapeutic effects were designed, prepared and evaluated as antitumor agents for the first time. Complex 4 with potent antitumor activities both in vitro and in vivo was screened out as a candidate. Notably, it displays significantly more effective anti-metastatic activities than the platinum(II) drugs cisplatin and oxaliplatin. Mechanism detection discloses that it causes serious DNA damage and increases the expression of γ-H2AX and P53. Then, the apoptosis of tumor cells is promoted by activating the mitochondrial apoptotic pathway Bcl-2/Bax/caspase-3 and causing autophagy via modulating LC3-I/II and P62 expression. Furthermore, the immune therapeutic responses are significantly elevated by blocking HIF-1α, ERK 1/2 and COX-2 pathways to reduce PD-L1 expression, and further increasing CD3+ and CD8+ T cells to elevate T cell immunity in tumors. Tumor metastasis is blocked by the synergistic functions of DNA damage, hypoxia modulation and immune activation. [ABSTRACT FROM AUTHOR]

To develop new chemotherapeutics with anti-metastasis properties, a series of multi-specific niflumic acid (NFA) platinum(IV) complexes with DNA damage, inflammation inhibition, immunity activation, and angiogenesis suppression mechanisms were designed, synthesized and evaluated as novel antitumor agents. The dual NFA platinum(IV) complex with a cisplatin core showed promising antitumor activities both in vitro and in vivo with lower toxicity than platinum(II) drugs and displayed attractive anti-metastasis performance. It caused serious DNA damage and further elevated the expression of γ-H2AX. Furthermore, it promoted apoptosis by activating the mitochondrial apoptotic pathway and autophagy of tumor cells. Moreover, immune response in tumors was significantly improved by increasing CD3+, CD4+ and CD8+ T infiltrating cells. Subsequently, the pathway ERK/HIF-1α/VEGFA associated with angiogenesis was suppressed by the reduced inflammation and elevated immune response, and the density of microvessels marked by CD34 was significantly reduced in tumors. Accordingly, the multi-specific NFA platinum(IV) complexes have great potential to be developed as novel anti-proliferative and anti-metastatic drugs. [ABSTRACT FROM AUTHOR]

The design of novel platinum(IV) complexes with mitochondria injury competence, besides the DNA damage mechanism, is a promising way to develop new platinum drugs. Herein, dihydro-2-quinolone (DHQLO) as a mitocan was incorporated into the platinum(IV) system for the first time to prepare a new series of DHQLO platinum(IV) compounds. Complex 1b could effectively inhibit the proliferation of tumor cells in vitro and in vivo. It accumulated at higher levels in both whole cells and DNA, and easily underwent intercellular reduction to release platinum(II) and DHQLO moieties. The released platinum(II) complex caused serious DNA damage by covalent conjunction with the DNA duplex, and remarkably increased the expression of the γ-H2AX protein. Moreover, 1b also caused serious mitochondria injury to induce mitochondrial membrane depolarization and increase ROS generation. Such actions upon DNA and mitochondria activate the p53 apoptotic pathway synergetically in tumor cells by upregulating the protein p53 and apoptotic proteins caspase9 and caspase3, which efficiently promoted the apoptotic death of tumor cells. Compound 1b with such synergic mechanism exhibited great potential in reversing cisplatin resistance and improving antitumor efficacies. [ABSTRACT FROM AUTHOR]

Cycloxygenases (COXs) and matrix metalloproteinases (MMPs) in the tumor microenvironment (TME) are tightly related to the progression of cancers. Here, naproxen as a potent inhibitor of both COX and MMP was combined with platinum(IV) to construct hybrids as antitumor agents. Compound 2 with comparable or even superior activities to that of cisplatin, oxaliplatin, and carboplatin, great potential for reversing drug resistance, and superior tumor targeting properties was screened out as a lead compound. Moreover, compound 2 possessed potent tumor growth inhibition capability in vivo, which was comparable to that of oxaliplatin, and displayed rather lower side effects than the platinum(II) reference drugs. The naproxen platinum(IV) complex could easily undergo reduction and liberate the platinum(II) complex and naproxen as well as exert a multifunctional antitumor mechanism: (i) the liberated platinum(II) fragment would cause serious DNA injury; (ii) naproxen would inhibit COX-2 and decrease tumor-associated inflammation; and (iii) the naproxen platinum(IV) complex exhibited remarkable MMP-9 inhibition in tumor tissues. These antitumor functions can help reduce the growth and metastasis of malignancy. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Bifunctional 7-hydroxycoumarin platinum(IV) complexes as antitumor agents. • Have much potential in overcoming cisplatin drug-resistance. • Antitumor mechanism was investigated. • Enhanced accumulation in whole cells and DNA. • Combination with HSA by noncovalent forces. Abstract A series of bi-functional 7-hydroxycoumarin platinum(IV) complexes were synthesized, characterized, and evaluated for antitumor activities. The 7-hydroxycoumarin platinum(IV) complexes display moderate to effective antitumor activities toward the tested cell lines and show much potential in overcoming drug resistance of platinum(II) drugs. In reducing microenvironment, the title compounds could be reduced to platinum(II) complex accompanied with two equivalents of coumarin units. By a unique mechanism, the 7-hydroxycoumarin platinum(IV) complex attacks DNA via the released platinum(II) compound, meanwhile it also inhibits the activities of cyclooxygenase by coumarin fragment. This action mechanism might be of much benefit for reducing tumor-related inflammation in the progress of inhibiting tumor proliferation and overcoming cisplatin resistance. The incorporation of 7-hydroxycoumarin leads to significantly enhanced platinum accumulation in both whole tumor cells and DNA. The HSA interaction investigation reveals that the tested coumarin platinum(IV) compound could effectively combine with HSA via van der Waals force and hydrogen bond. [ABSTRACT FROM AUTHOR]

Abstract Naphthalimide platinum(IV) antitumor complexes with potential dual DNA damage mechanism were designed, synthesized and evaluated for antitumor activities. The incorporation of DNA targeted naphthalimide group to the platinum(IV) system exerts much positive impacts on their antitumor efficacy. The mechanism research reveals that the title compounds could interact with dsDNA in platinum(IV) form via the naphthalimide group and cause DNA lesion. The further reduction would release platinum(II) complexes and naphthalimide acids which would induce remarkable secondary damage to DNA. Furthermore, the naphthalimide platinum(IV) compounds could combine with human serum albumin via electrostatic force, which are favourable for their storage and transport in blood. Moreover, the title compounds exhibit higher accumulation in tumor cells, and exert lower toxic and higher safe properties than oxaliplatin in vivo. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Conjugates (A1–A5) of the Pt(iv) derivative (A6) with amino groups from peracetyl glucose, rhamnose and mannose with a propyl amino or ethyl amino linker at the reducing end were synthesized and exhibited significant therapeutic efficacy in tumour cells, especially for prostate cancer (PCa). The antitumor activities are greatly affected by glycosyl groups. Cytotoxic experiments in vitro indicated that the antitumor activities were increased by 5-fold when its Pt(iv) derivative was conjugated to S18 (IC50 = 4.82 ± 0.45 μM) and by 12-fold when conjugated to S21 (IC50 = 1.9 ± 0.67 μM). The mannose substituted Pt(iv) complexes A4 and A5 were also over an order of magnitude more potent towards HeLa, A549, MCF-7 and PC3 than cisplatin and oxaliplatin. Importantly, the glycosylated Pt(iv) derivatives A4 and A5 displayed potential safety for clinical therapeutic exposure with IC50 of 84 μM and 169 μM compared with cisplatin (IC50 = 8 μM) to 3T3. Cellular uptake and DNA platination are higher than cisplatin and oxaliplatin. ESI-MS analysis of A5 binding to 5′-dGMP revealed that bifunctional DNA lesions were formed. The antitumor activities in vivo showed that the MTD and LD50 for A4 and A5 are nearly 4-fold higher than that of oxaliplatin indicating the potential safety for the glycosylated Pt(iv) complexes. [ABSTRACT FROM AUTHOR]

Mitophagy is an important target for antitumor drugs development. A series of ciclopirox (CPX) platinum(IV) hybrids targeting PTEN induced putative kinase 1 (PINK1)/Parkin mediated mitophagy were designed and prepared as antitumor agents. The dual CPX platinum(IV) complex with cisplatin core was screened out as a candidate, which displayed promising antitumor activities both in vitro and in vivo. Mechanistically, it caused serious DNA damage in tumor cells. Then, remarkable mitochondrial damage was induced accompanied by the mitochondrial membrane depolarization and reactive oxygen species generation, which further promoted apoptosis through the Bcl-2/Bax/Caspase3 pathway. Furthermore, mitophagy was ignited via the PINK1/Parkin/P62/LC3 axis, and exhibited positive influence on promoting the apoptosis of tumor cells. The antitumor immunity was boosted by the block of immune check point programmed cell death ligand-1 (PD-L1), which further increased the density of T cells in tumors. Subsequently, the metastasis of tumor cells was inhibited by inhibiting angiogenesis in tumors. Ciclopirox platinum(IV) hybrids were designed and prepared as antitumor agents, which activated by damaging mitochondria, provoking prodeath mitophagy, and activating immune responses in tumor tissues, besides inducing DNA damage. A candidate complex was screened out possessing potent antitumor efficacy in vivo but causing rather low toxicity. [Display omitted] • Ciclopirox platinum(IV) complexes were developed as new potent antitumor agents. • Effective in igniting mitophagy and boosting T cell immunity. • Inhibit tumor metastasis by inhibiting angiogenesis. [ABSTRACT FROM AUTHOR]

Abstract A series of new 4-hydroxycoumarin platinum(IV) complexes were designed, synthesized and evaluated as antitumor agents. All the title compounds display moderate to effective antitumor activities toward the tested cell lines and two prominent compounds were screened out with activities comparable to cisplatin and oxaliplatin. The mechanism investigation demonstrates that the platinum(IV) compounds could be reduced to bivalence and exert significant genotoxicity to tumor cells. Meanwhile the coumarin moiety endows the title compounds with cyclooxygenase inhibitory competence which might favour the reduction of tumor-related inflammation and further influence tumor proliferation. The coumarin platinum(IV) complex could effectively induce apoptosis of SKOV-3 cells through up-regulating the expression of caspase3 and caspase9. Furthermore, the conversion of platinum(II) drugs to platinum(IV) form via the conjunction with 4-hydroxycoumarin enhances the drug uptake in whole cells and DNA simultaneously. Moreover, the 4-hydroxycoumarin platinum(IV) complex could combine with human serum albumin via van der Waals force and hydrogen bond, which would influence their transport and bioactivities in vivo. Graphical abstract New 4-hydroxycoumarin platinum(IV) hybrids were designed, synthesized and evaluated as antitumor agents. The platinum(IV) core could be reduced to bivalence and display significant genotoxicity. Meanwhile the coumarin group endows the title compounds with cyclooxygenase inhibitory competence which would favour of reducing tumor-related inflammation and further influencing tumor proliferation. Unlabelled Image Highlights • Development of 4-hydroxycoumarin platinum(IV) hybrids as antitumor agents • Antitumor activities were evaluated and the action mechanism was investigated. • Active apoptotic pathway by up-regulating the expression of caspase3 and caspase9 • Exert higher accumulation in both whole cells and DNA than platinum(II) drugs • Combine with human serum albumin effectively by noncovalent forces [ABSTRACT FROM AUTHOR]

Herein, novel laser-responsive multi-functional nanoparticles (NPs-Lip@PTX/CyA/Ce6) were fabricated with bovine serum albumins (BSA) based nanoparticles, which simultaneously carried chemotherapeutic drug paclitaxel (PTX) and P-gp inhibitor cyclosporin A (CyA), as core and photosensitizer agent Chlorin e6 (Ce6) loaded Tf-modified liposomal bilayer as shell. NPs-Lip@PTX/CyA/Ce6 exhibited apparent core-shell structure morphology with particle size of 160.9 ± 1.7 nm and zeta potential of − 26.7 ± 0.6 mV, indicating their excellent stability in aqueous solution. Besides, NPs-Lip@PTX/CyA/Ce6 possessed laser-responsive release profiles upon laser irradiation at specific wavelength, which was favor to exert efficient combinatorial chemo-photodynamic therapy and effectively reverse the multiple drug resistance (MDR). Under laser irradiation, as expected, NPs-Lip@PTX/CyA/Ce6 demonstrated superb intracellular ROS productivity and fantastic in vitro and in vivo anti-cancer therapy effect but absent of systemic toxicity. In conclusion, the nano-drug delivery system would be prospectively applied in clinic as resultful therapeutic tactic for investing compositional chemo-photodynamic therapy synergistically. [Display omitted] • Novel laser-responsive multi-functional NPs-Lip@PTX/CyA/Ce6 were fabricated. • NPs-Lip showed apparent core-shell structure morphology and excellent stability. • NPs-Lip possessed laser-responsive release profiles. • NPs-Lip exhibited superb cellular 1O 2 productivity and uptake efficiency. • NPs-Lip displayed fantastic antitumor efficacy but absent of systemic toxicity. [ABSTRACT FROM AUTHOR]