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Hypoxia-inducible factor-1 (HIF-1), an essential promoter of tumor progression, has attracted increasing attention as a therapeutic target. In addition to hypoxic cellular conditions, HIF-1 activation can be triggered by cancer treatment, which causes drug tolerance and therapeutic failure. To date, a series of effective strategies have been explored to suppress HIF-1 function, including silencing the HIF-1α gene, inhibiting HIF-1α protein translation, degrading HIF-1α protein, and inhibiting HIF-1 transcription. Furthermore, nanoparticle-based drug delivery systems have been widely developed to improve the stability and pharmacokinetics of HIF-1 inhibitors or achieve HIF-1-targeted combination therapies as a nanoplatform. In this review, we summarize the current literature on nanomedicines targeting HIF-1 to combat cancer and discuss their potential for future development.

Drug transportation is impeded by various barriers in the hypoxic solid tumor, resulting in compromised anticancer efficacy. Herein, a solid lipid monostearin (MS)-coated CaO2/MnO2 nanocarrier was designed to optimize doxorubicin (DOX) transportation comprehensively for chemotherapy enhancement. The MS shell of nanoparticles could be destroyed selectively by highly-expressed lipase within cancer cells, exposing water-sensitive cores to release DOX and produce O2. After the cancer cell death, the core-exposed nanoparticles could be further liberated and continue to react with water in the tumor extracellular matrix (ECM) and thoroughly release O2 and DOX, which exhibited cytotoxicity to neighboring cells. Small DOX molecules could readily diffuse through ECM, in which the collagen deposition was decreased by O2-mediated hypoxia-inducible factor-1 inhibition, leading to synergistically improved drug penetration. Concurrently, DOX-efflux-associated P-glycoprotein was also inhibited by O2, prolonging drug retention in cancer cells. Overall, the DOX transporting processes from nanoparticles to deep tumor cells including drug release, penetration, and retention were optimized comprehensively, which significantly boosted antitumor benefits.

The unfavorable factors in tumor microenvironment such as hypoxia and limited H2O2 levels greatly impede the anticancer efficacy of chemotherapy and chemodynamic therapy (CDT). To address these issues and achieve O2/H2O2-sufficient chemo/chemodynamic combination therapy, we synthesized a solid lipid monostearin coated calcium peroxide (CaO2) nanocarrier for the co-delivery of a chemotherapeutic drug doxorubicin (DOX) and a biocompatible Fenton catalyst iron-oleate complex. Specifically, the solid lipid shells of nanoparticles could disintegrate in lipase-overexpressed cancer cells to release iron-oleate and expose CaO2 cores. Afterwards, the uncovered CaO2 responded to the acidic aqueous environment within cancer cells, leading to the release of DOX molecules and generation of H2O2. Based on Fenton reactions, Fe3+ liberated from iron-oleate reacted with H2O2 to produce O2 for hypoxia-relieved chemotherapy, and Fe2+ for the catalytic generation of hydroxyl radical to initiate CDT. Both treatments synergistically contribute to the enhanced antitumor outcomes.

Antibody drug conjugates (ADCs) normally compose of a humanized antibody and small molecular drug via a chemical linker. After decades of preclinical and clinical studies, a series of ADCs have been widely used for treating specific tumor types in the clinic such as brentuximab vedotin (Adcetris®) for relapsed Hodgkin's lymphoma and systemic anaplastic large cell lymphoma, gemtuzumab ozogamicin (Mylotarg®) for acute myeloid leukemia, ado-trastuzumab emtansine (Kadcyla®) for HER2-positive metastatic breast cancer, inotuzumab ozogamicin (Besponsa®) and most recently polatuzumab vedotin-piiq (Polivy®) for B cell malignancies. More than eighty ADCs have been investigated in different clinical stages from approximately six hundred clinical trials to date. This review summarizes the key elements of ADCs and highlights recent advances of ADCs, as well as important lessons learned from clinical data, and future directions., Graphical abstract Antibody drug conjugates (ADCs), normally composed of a humanized antibody and small molecular drugs via chemical linkers, represent a rapidly growing field for cancer therapy. In this review, we provide an overview of ADCs in preclinical and clinical development, as well as future directions of ADCs.Image 1

Platinum-based chemotherapy is used for non-small cell lung cancer (NSCLC). However, it has side effects and minimum efficacy against lung cancer metastasis. In this study, platinum–curcumin complexes were loaded into pH and redox dual-responsive nanoparticles (denoted as Pt–CUR@PSPPN) to facilitate intracellular release and synergistic anti-cancer effects. Pt–CUR@PSPPN was prepared by a nano-precipitation method and had a diameter of ∼100 nm. The nanoparticles showed increased anti-cancer effects both in vivo and in vitro. In addition, Pt–CUR@PSPPN blocked PI3K/AKT signal transduction pathway and inhibited MMP2 and VEGFR2, resulting in enhanced anti-metastatic activity. Furthermore, reduced side effects were also observed. In conclusion, Pt–CUR@PSPPN provided a novel and attractive therapeutic strategy for NSCLC., Graphical abstract Pt–CUR@PSPPN showed increased anti-cancer effects both in vitro and in vivo. The nanoparticles blocked PI3K/AKT signal transduction pathway and inhibited MMP2 and VEGFR2, resulting in enhanced anti-metastatic activity. In addition, reduced nephrotoxicity was also observed.Image 1

Resistance of hepatocellular carcinoma (HCC) to systemic chemotherapy is partially due to presence of drug-resistant cancer stem cells. Bmi1 protein is essential for survival and proliferation of HCC cancer stem cells (CSCs). Here, we report that Bmi1 siRNA (Bmi1siR) loaded in cationic nanocapsules of cisplatin (NPC) eliminated stem cells in situ HCC in mice. NPC/Bmi1siR was fabricated via electrostatic complexation of Bmi1 siRNA to NPCs, which had cores composed of cisplatin and were coated with cationic lipids. In vivo, NPC/Bmi1siR showed higher anti-tumor activity in HCC bearing mice compared with cisplatin or NPC. Critically, both flow cytometry (FACS) analysis in vitro and histological examination in vivo revealed that side population or CD133+ HCC cells were dramatically decreased by NPC/Bmi1siR treatment, suggesting that HCC CSCs were eliminated. Altogether, our results suggest that drug resistance of HCC can be overcome by co-delivering Bmi1 siRNA with cisplatin in cationic nanocapsules.

Sorafenib is a first-line drug for hepatocellular carcinoma (HCC). Autophagy has been shown to facilitate sorafenib resistance. miR-375 has been shown to be an inhibitor of autophagy. In this study, miR-375 and sorafenib were co-loaded into calcium carbonate nanoparticles with lipid coating (miR-375/Sf-LCC NPs). The nanoparticles had high loading efficiency and were ∼50 nm in diameter. Besides, the NPs could increase the stability and residence time of both drugs. Moreover, we demonstrated that autophagy was activated in HCC cells by sorafenib but not by miR-375/Sf-LCC NPs. In vitro, miR-375/Sf-LCC NPs exhibited pH-dependent drug release and potent cytotoxicity. In vivo, miR-375/Sf-LCC NPs increased miR-375 and sorafenib uptake in tumor (2 folds compared with Lipofectamine 2000-miR-375 and 2–5 folds compared with free sorafenib). Furthermore, miR-375/Sf-LCC NPs showed greatly enhanced therapeutic efficacy in an HCC xenograft model. These findings suggest that miR-375/Sf-LCC NPs may be a promising agent for the HCC therapy. Statement of Significance Hepatocellular carcinoma (HCC) is the most common primary liver tumor and the third leading cause of cancer mortality globally. In this manuscript, miR-375 and sorafenib were co-loaded into calcium carbonate nanoparticles with lipid coating (miR-375/Sf-LCC NPs) to treat HCC. We demonstrated that miR-375/Sf-LCC NPs can deliver sorafenib and miR-375 into HCC cells and tumor tissues, increase drug retention time in tumor, significantly inhibit autophagy and produce enhanced anti-tumor effect.

Chemo-immunotherapy has the superiority of remedying malignant and metastatic tumors, and acquiring better therapeutic effect as well as prognosis than monotherapy. Herein, we report a kind of pH-responsive core-shell nanoparticles to achieve the co-delivery of oxaliplatin intermediate (oxa im) (HCLO NPs) and cytosine-guanine containing oligodeoxynucleotides (CpG) for cancer treatment. The nanoparticles comprise the core of lipid-coated calcium carbonate and the outer layer of hyaluronic acid (HA), providing itself with pH-sensitivity and great biocompatibility. When intratumorally injected, oxa im induces in situ antigen production through immunogenic cell death (ICD) while CpG enhances antigen presentation and facilitates the generation of cytotoxic T lymphocytes (CTLs). In vitro, the HCLO NPs enhanced the toxicity of oxa im to CT26 cells and up-regulated the expression of calreticulin (CRT, “eat me” signal). What’s more, oxaliplatin precursor (oxa pre) directly upregulated CD47 (“don’t eat me” signal) expression in CT26 cells, while being encapsulated into NPs attenuated this upregulation. In vivo, HCLO NPs elicited prominent anti-tumor immunity and abscopal effect, meanwhile significantly increased the infiltration of CD8+ T cells in the tumor microenvironment.

Hydroxyl radical (·OH)-mediated chemodynamic therapy (CDT) and glucose oxidase (GOx)-based starvation therapy (ST) are two emerging antitumor strategies, limited by acid/H2O2 deficiency and tumor hypoxia, respectively. Herein, we developed a liposomal nanoplatform co-delivering Fe(OH)3-doped CaO2 nanocomposites and GOx molecules for synergistic CDT/ST with a complementary effect. Based on Fenton reactions initiated by iron ions, CaO2-supplied H2O2 could not only generate ·OH for H2O2-sufficient CDT, but also produce O2 to promote the catalytic efficiency of GOx under hypoxia. In return, the enhanced ST generated gluconic acid and H2O2, further amplifying CDT. Through in vitro and in vivo experiments, we demonstrated that such a mutually reinforced modality based on the cyclic Fenton/starvation reactions provided a novel and potent anticancer mechanism for the effective treatment of hypoxic cancers.

A series of novel ruthenium(II)-cymene complexes ( 1 – 9 ) with substituted α -dicarbonylmonoximes of general formula [Ru(η 6 -cymene)(L)Cl] (L = N,O-chelating bidentate α -dicarbonylmonoxime derivatives) have been synthesized and characterized by elemental analysis, IR, 1 H NMR, 13 C NMR spectroscopies, and in three cases by single crystal X-ray diffraction analysis. The most effective compound 9 displays remarkable anti-invasion and anti-metastasis properties without apparent cytotoxicity toward three different human cancer cell lines (MCF-7, Hela and HepG2). Further protein level studies suggest that the anti-metastasis activity of the complexes may result from the increasing expression of E-cadherin and reducing expression of Vimentin.

Doxorubicin (DOX) is one of the most frequently used anti-cancer drugs and the front line option for hepatocellular carcinoma (HCC) treatment. However, the clinical applications of DOX are restricted largely due to its toxicity and chemoresistance. Here, we report that miR-375 and DOX were co-delivered by liposomes (named L-miR-375/DOX-NPs) for combination therapy of HCC and drug resistance reversion of DOX. In vitro, L-miR-375/DOX-NPs could deliver DOX and miR-375 efficiently and simultaneously into HCC cells and ensure the successful release of mature miR-375 and DOX. Then, the released miR-375 suppressed the malignant hallmarks of HCC by significantly decreasing the expression of AEG-1, YAP1, and ATG7, while the released DOX evidently accelerated cell apoptosis and blocked cycle at a G2/M stage by activating the P53/Bax/Bcl-2, caspase-3, and P-JNK, P-P38 pathway. Furthermore, miR-375 dramatically inhibited drug resistance of DOX by reducing the expression of multidrug resistance gene 1 (MDR1). In vivo, L-miR-375/DOX-NPs exhibited enhanced anti-tumor efficiency in xenograft HCC mouse models with mild adverse effects compared with doxorubicin or miR-375 alone. In conclusion, our research demonstrated that L-miR-375/DOX-NPs had significant synergetic anti-tumor effects and added values in overcoming drug resistance, which may represent a promising approach for the therapy of HCC.

The emergence and spread of multidrug-resistant strains of the human pathological bacteria are generating a threat to public health worldwide. In the current study, a series of PC190723 derivatives was synthesized and investigated for their antimicrobial activity. The compounds exhibited good activity against several Gram-positive bacteria as determined by comparison of diameters of the zone of inhibition of test compounds and standard antibiotics. Compound 9 with a fluorine substitution on the phenyl ring showed the best antibacterial activity in the series against M. smegmatis with the zone ratio of 0.62, and against S. aureus with the zone ratio of 0.44. The results from this study indicate that based on the unique 3-methoxybenzamide pharmacophore, compound 9 may represent a promising lead candidate against Gram-positive bacteria that are worthy of further investigation.

Previously, we have reported a lipid-based Trp2 peptide vaccine for immunotherapy against melanoma. The suppressive immune microenvironment in the tumor is a major hurdle for an effective vaccine therapy. We hypothesized that curcumin (CUR) would remodel the tumor microenvironment to improve the vaccine activity. Curcumin–polyethylene glycol conjugate (CUR–PEG), an amphiphilic CUR-based micelle, was delivered intravenously (i.v.) to the tumor. Indeed, in the B16F10 tumor–bearing mice, the combination of CUR–PEG and vaccine treatment resulted in a synergistic antitumor effect (P < 0.001) compared to individual treatments. In the immune organs, the combination therapy significantly boosted in vivo cytotoxic T-lymphocyte response (41.0 ± 5.0% specific killing) and interferon-γ (IFN-γ) production (sevenfold increase). In the tumor microenvironment, the combination therapy led to significantly downregulated levels of immunosuppressive factors, such as decreased numbers of myeloid-derived suppressor cells and regulatory T cells (Treg) cells and declined levels of interleukin-6 and chemokine ligand 2—in correlation with increased levels of proinflammatory cytokines, including tumor necrosis factor-α and IFN-γ as well as an elevation in the CD8+ T-cell population. The results indicated a distinct M2 to M1 phenotype switch in the treated tumors. Combining CUR–PEG and vaccine also dramatically downregulated the signal transducer and activator of transcription 3 pathway (76% reduction). Thus, we conclude that CUR–PEG is an effective agent to improve immunotherapy for advanced melanoma.

Iron depletion is an efficient strategy for the development of anticancer agents. In an effort to develop efficient chelators, two new 3-hydroxy-4-pyridinone based polyazamacrocycles 1e and 2e were designed and synthesized. A preliminary study of the ligands was carried out to investigate their iron chelating capability and anti-tumor activity. Chelating kinetics revealed that the ligands exhibited excellent iron depletion capacity in neutral and acidic NH4OAc buffer solutions. Moreover, MTT assay showed that the new ligands displayed potent inhibitory activity in the proliferation of HepG2 cells. The attachment of hydroxypyridione units on the polyazamacrocycles promoted iron chelating capability and improved the anti-tumor activity by offering additional chelating sites and lipophilicity. These results indicate that two novel compounds may possess the therapeutic potential in the treatment of cancer through depleting cellular iron.

The clinical efficacy of cisplatin (DDP) treatment is largely limited by cisplatin resistance, which is related to the activation of hypoxia-inducible factor 1 (HIF-1). The HIF-1 activation can be induced by low oxygen availability as well as chemotherapeutics in a reactive oxygen species (ROS) dependent manner. Here, instead of the traditional ROS elevation strategy, we designed a chitosan-coated selenium/DDP (CSP) nanoparticle to deplete ROS for circumventing acquired cisplatin resistance. The antioxidative selenium nanoparticles were demonstrated to eliminate cisplatin-induced ROS, and further prevent HIF-1 activation accompanied with cisplatin treatment. A series of cisplatin resistance-associated proteins including glutamate-cysteine ligase modifier subunit (GCLM) and multidrug resistance-associated proteins (MRPs) expression were downregulated in a HIF-1α-dependent manner. And in vitro and in vivo experiments showed that CSP nanoparticles exhibited enhanced antitumor efficacy to cisplatin-resistant A549/DDP lung cancer cell lines and xenografts. These results proved that the side effects of treatment-induced ROS in HIF-1 activation and cisplatin-resistance could be significantly reversed by a selenium nanovehicle, which may possess broader applications in ROS-mediated resistance or other ROS-involved diseases.

Bmi-1 is a gene related to malignant transformation in hepatocellular carcinoma (HCC). The liver cancer cells developed the ability to tolerate CDDP treatment with the elevation of Bmi-1. Bmi-1 is also an oncogene promoting malignance of tumor and an anti-cancer target in many studies. Herein, a biocompatible nanocarrier was designed in the study to deliver a chemotherapeutical agent CDDP and Bmi-1 siRNA to kill cancer cells and silence drug resistance related gene simultaneously. Calciumphosphate (CaP) was applied to coat both nanoplatin cores and siRNA as a shell for the purpose of delivering cargos to the cytosol of the tumor cells. Nanoplatin and siRNA co-loaded CaP nanoparticles (NPSC) enhanced cell uptake of CDDP and showed elevated drug accumulation in tumor. NPSC achieved considerable anti-cancer efficacy and counter-regulated drug tolerance, therefore, warranted a further investigation as a novel therapeutic nanosystem to improve cancer therapy.

Two classes of dibutyltin(IV) hydroxamates complexes, formulated as the mononuclear mixed-ligand diorganotin(IV) complex [(n)Bu(2)Sn(HL)Cl] a and the tetranuclear [(n)Bu(4)Sn(2)(HL)(2)(L)](2)b were fully characterized. X-ray diffraction analyses were also carried out for the representative complexes [(n)Bu(2)Sn(2,6-F(2)C(6)H(3)C(O)NHO)Cl](4a) and [[(n)Bu(4)Sn(2){3-BrC(6)H(4)C(O)NHO}(2){3-BrC(6)H(4)C(NO)O}](2)](1b). The cytotoxicity of all compounds was tested by MTT and SRB assays against three human tumor cell lines HL-60, BGC-823 and KB. 1b and 4a have been shown to be more potent antitumor agents than other compounds and cisplatin. Annexin V FITC-PI assay was consistent with the MTT results. Cell cycle assay results indicated that KB cells displayed an arrest in the G(0)/G(1) phase and a decrease of S phase of the cell cycle at the low concentrations of 1b, 4a.

Folate receptors (FRs) have been identified as cellular surface markers for cancer and leukemia. Liposomes containing lipophilic derivatives of folate have been shown to effectively target FR-expressing cells. Here, we report the synthesis of a novel lipophilic folate derivative, folate-polyethylene glycol-cholesterol hemisuccinate (F-PEG-CHEMS), and its evaluation as a targeting ligand for liposomal doxorubicin (L-DOX) in FR-expressing cells. Liposomes containing F-PEG-CHEMS, with a mean diameter of 120+/-20 nm, were synthesized by polycarbonate membrane extrusion and were shown to have excellent colloidal stability. The liposomes were taken up selectively by KB cells, which overexpress FR-alpha. Compared to folate-PEG-cholesterol (F-PEG-Chol), which contains a carbamate linkage, F-PEG-CHEMS better retained its FR-targeting activity during prolonged storage. In addition, F-PEG-CHEMS containing liposomes loaded with DOX (F-L-DOX) showed greater cytotoxicity (IC(50)=10.0muM) than non-targeted control L-DOX (IC(50)=57.5 microM) in KB cells. In ICR mice, both targeted and non-targeted liposomes exhibited long circulation properties, although F-L-DOX (t(1/2)=12.34 h) showed more rapid plasma clearance than L-DOX (t(1/2)=17.10h). These results suggest that F-PEG-CHEMS is effective as a novel ligand for the synthesis of FR-targeted liposomes.