Development of Anticancer Ferric Complex Based on Human Serum Albumin Nanoparticles That Generate Oxygen in Cells to Overcome Hypoxia-Induced Resistance in Metal Chemotherapy.

To achieve the remarkable therapeutic efficacy of a ferric (Fe) complex via a reactive oxygen species (ROS) mechanism in solid tumors, a therapeutic Fe-based Schiff-base complex (Fe1) was synthesized and encapsulated in human serum albumin (HSA) nanoparticles (NPs), which generated oxygen (O2) in cancer cells in situ. The HSA-Fe1-O2 NP (HSA-Fe1-O2NP) delivery system effectively overcame hypoxia-induced resistance in metal chemotherapy, alleviated the hypoxic condition of tumor tissues, and showed excellent tumor suppression by generating excess ROS and promoting the apoptosis of SK-N-MC tumor cells. The HSA-Fe1-O2NPs not only enhanced the ability of the Fe1 complex to target tumor cells but also decreased adverse effects in vivo.

Role of Ubiquitin-specific Proteases in Hepatocellular Carcinoma Pathogenesis.

Signaling pathways in hepatocellular carcinoma are primarily mediated by the phosphorylation and ubiquitination of post-translational proteins. In mammalian cells, ubiquitin-specific proteases (USPs) account for the majority of protein deubiquitination activities. In addition to transcriptional and post-translational regulation, ubiquitination plays an important role in the regulation of key proteins. There is a possibility that altered biological processes may lead to serious human diseases, including cancer. Recent studies have revealed the role of USPs in hepatocellular carcinoma tumorigenesis. The purpose of this review is to summarize the involvement of this class of enzymes in the regulation of cell signaling in hepatocellular carcinoma and the therapeutic development of inhibitors that target USPs, which may lead to novel therapies to treat hepatocellular carcinoma.

Encapsulation of Au(III) Complex Using Lactoferrin Nanoparticles to Combat Glioma.

Metal-based drugs have been used for decades to treat solid cancers; however, these drugs have no significant therapeutic effect on glioma because they cannot effectively cross the blood-brain barrier (BBB). To develop a novel metal-based agent that can cross the BBB to target glioma, we synthesized an Au complex (C2) with remarkable glioma cytotoxicity and fabricated lactoferrin (LF)-C2 nanoparticles (LF-C2 NPs) as a novel therapy. We confirmed that C2 kills glioma cells by inducing apoptosis and autophagic death. The LF-C2 NPs cross the BBB, inhibit glioma growth, and selectively accumulate in the tumor tissue, significantly decreasing the side effects of C2. This study provides a novel strategy for applying metal-based agents to targeted therapy for glioma.

Developing an Anticancer Platinum(II) Compound Based on the Uniqueness of Human Serum Albumin.

To develop the next-generation Pt drug with remarkable activity and low toxicity to maximally inhibit tumor growth, we optimized a Pt(II) thiosemicarbazone compound (C4) with remarkable cytotoxicity to SK-N-MC cells and then constructed a new human serum albumin-C4 (HSA-C4) complex delivery system. The in vivo results showed that C4 and the HSA-C4 complex have remarkable therapeutic efficiency and almost no toxicity; they induced apoptosis and inhibited tumor angiogenesis. This system showed potential as a practical Pt drug. This study could pave the way for developing next-generation dual-targeted Pt drugs and achieving their targeting therapy for cancer.

Robust Control Allocation for Space Inertial Sensor under Test Mass Release Phase with Overcritical Conditions.

This paper proposes a robust control allocation for the capture control of the space inertial sensor's test mass under overcritical conditions. Uncertainty factors of the test mass control system under the overcritical condition are analyzed first, and a 6-DOF test mass dynamics model with system uncertainty is established. Subsequently, a time-varying weight function is designed to coordinate the allocation of 6-DOF generalized forces. Moreover, a robust control allocation method is proposed to distribute the commanded forces and torques into individual electrodes in an optimal manner, which takes into account the system uncertainties. This method transforms the robust control allocation problem into a second-order cone optimization problem, and its dual problem is introduced to simplify the computational complexity and improve the solving efficiency. Numerical simulation results are presented to illustrate and highlight the fine performance benefits obtained using the proposed robust control allocation method, which improves capture efficiency, increases the security margin and reduces allocation errors.

Adaptive Control for Gravitational Wave Detection Formation Considering Time-Varying Communication Delays.

A distributed six-degree-of-freedom (6-DOF) cooperative control for multiple spacecraft formation is investigated considering parametric uncertainties, external disturbances, and time-varying communication delays. Unit dual quaternions are used to describe the kinematics and dynamics models of the 6-DOF relative motion of the spacecraft. A distributed coordinated controller based on dual quaternions with time-varying communication delays is proposed. The unknown mass and inertia, as well as unknown disturbances, are then taken into account. An adaptive coordinated control law is developed by combining the coordinated control algorithm with an adaptive algorithm to compensate for parametric uncertainties and external disturbances. The Lyapunov method is used to prove that the tracking errors converge globally asymptotically. Numerical simulations show that the proposed method can realize cooperative control of attitude and orbit for the multi-spacecraft formation.

Continuous Low-Thrust Maneuver Planning for Space Gravitational Wave Formation Reconfiguration Based on Improved Particle Swarm Optimization Algorithm.

This study proposes a three-spacecraft formation reconfiguration strategy of minimum fuel for space gravitational wave detection missions in the high Earth orbit (105 km). For solving the limitations of measurement and communication in long baseline formations, a control strategy of a virtual formation is applied. The virtual reference spacecraft provides a desired relative state between the satellites, which is then used to control the motion of the physical spacecraft to maintain the desired formation. A linear dynamics model based on relative orbit elements' parameterization is used to describe the relative motion in the virtual formation, which facilitates the inclusion of J2, SRP, and lunisolar third-body gravity effects and provides a direct insight into the relative motion geometry. Considering the actual flight scenarios of gravitational wave formations, a formation reconfiguration strategy based on continuous low thrust is investigated to achieve the desired state at a given time while minimizing interference to the satellite platform. The reconfiguration problem is considered a constrained nonlinear programming problem, and an improved particle swarm algorithm is developed to solve this problem. Finally, the simulation results demonstrate the performance of the proposed method in improving the maneuver sequence distribution and optimizing maneuver consumption.

Attitude-Orbit Coupled Control of Gravitational Wave Detection Spacecraft with Communication Delays.

In order to meet the position and attitude requirements of spacecrafts and test masses for gravitational-wave detection missions, the attitude-orbit coordination control of multiple spacecrafts and test masses is studied. A distributed coordination control law for spacecraft formation based on dual quaternion is proposed. By describing the relationship between spacecrafts and test masses in the desired states, the coordination control problem is converted into a consistent-tracking control problem in which each spacecraft or test mass tracks its desired states. An accurate attitude-orbit relative dynamics model of the spacecraft and the test masses is proposed based on dual quaternions. A cooperative feedback control law based on a consistency algorithm is designed to achieve the consistent attitude tracking of multiple rigid bodies (spacecraft and test mass) and maintain the specific formation configuration. Moreover, the communication delays of the system are taken into account. The distributed coordination control law ensures almost global asymptotic convergence of the relative position and attitude error in the presence of communication delays. The simulation results demonstrate the effectiveness of the proposed control method, which meets the formation-configuration requirements for gravitational-wave detection missions.

Combined effects of vitamin D and neferine on the progression and metastasis of colorectal cancer.

PURPOSE: To investigate the synergistic effect of vitamin D and neferine on the growth and metastasis of colorectal cancer (CRC). METHODS: The synergistic effect of biologically active form of vitamin D, VD3 and neferine on the treatment of CRC was investigated by bliss analysis. Colony formation and wound healing ability, migration and invasion ability, and epithelial mesenchymal transition of HCT-116 cells, as a response to the combination treatment with VD3 and neferine were evaluated. RESULTS: VD3 and neferine showed a synergistic effect on CRC cell growth at a relatively low dose. The wound healing and colony formation capacity, cell migration and invasion abilities were all decreased by combination use of VD3 and neferine, compared to the VD3 or neferine treated single group. Furthermore, VD3 and neferine significantly decreased the expressions of N-cadherin, vimentin, snail, and slug in HCT-116 cells. CONCLUSION: These data suggest that neferine enhances the anticancer capability of VD3 and reduces the dose dependency of VD3. The combination of vitamin D with neferine appears to be a potential therapeutic strategy for CRC.

Developing a Gallium(III) Agent Based on the Properties of the Tumor Microenvironment and Lactoferrin: Achieving Two-Agent Co-delivery and Multi-targeted Combination Therapy of Cancer.

To develop a next-generation anticancer metal-based drug, realize the multi-targeted combination therapy of protein drug and metal-based drug for cancer, solve their co-delivery challenges, and improve their in vivo targeting ability, we proposed to develop a multi-targeted anticancer metal-based agent exploiting the properties of the tumor microenvironment (TME) and of lactoferrin (LF). To this end, we optimized a series of gallium (Ga, III) isopropyl-2-pyridyl-ketone thiosemicarbazone compounds to obtain a Ga compound (C4) with remarkable cytotoxicity and then constructed a new LF-C4 nanoparticle (LF-C4 NP) delivery system. In vivo studies showed that LF-C4 NPs not only had a greater capacity for inhibiting tumor growth than LF or C4 alone but also solved the co-delivery problems of LF and C4 and improved their targeting ability. Furthermore, free C4 and LF-C4 NPs inhibited tumor growth through multiple synergistic actions on the TME: killing cancer cell, inhibiting tumor angiogenesis, and activating immune system.

Designing a multitarget In(III) compound to overcome the resistance of lung cancer cells to cisplatin.

Designing novel anticancer non-platinum metal agents is fully challenging. Herein, a series of little-known indium (In) 2-acetylpyridine thiosemicarbazone compounds as potential anticancer agents were designed, synthesized, and characterized. The hydrogen atoms at the N-4 position with the alkyl of the In compounds significantly increased cellular uptake and cytotoxicity. In(III) compounds showed significantly higher cytotoxicity toward cisplatin-resistant cell lines than cisplatin. More importantly, C4 greatly inhibited A549DDP tumor growth in a vaccinated mouse model. C4 exerted cytotoxic effects via a multitarget mechanism. First, it activated p53 and blocked the cell cycle at the S phase, which then led to weak expression levels of cyclin and related kinases and upregulation of the expression levels of cyclin-dependent kinase inhibitors. C4 also depolarized the mitochondrial membrane potential and regulated the expression of the Bcl-2 family, which then released cyt-c and activated caspase-3/8/9 to execute apoptotic pathways. Then, it inhibited telomerase through the inhibition of the expression of the c-Myc regulator gene and expression of the human telomerase reverse transcriptase. Furthermore, C4 showed excellent antimetastatic activity.

Organometallic gold(I) and gold(III) complexes for lung cancer treatment.

Metal compounds, especially gold complexes, have recently gained increasing attention as possible lung cancer therapeutics. Some gold complexes display not only excellent activity in cisplatin-sensitive lung cancer but also in cisplatin-resistant lung cancer, revealing promising prospects in the development of novel treatments for lung cancer. This review summarizes examples of anticancer gold(I) and gold (III) complexes for lung cancer treatment, including mechanisms of action and approaches adopted to improve their efficiency. Several excellent examples of gold complexes against lung cancer are highlighted.

Synthesis and in vitro/in vivo anticancer evaluation of pentacyclic triterpenoid derivatives linked with l-phenylalanine or l-proline.

Extensive research effort has been put in pentacyclic triterpenoids due to their numerous biological activities. However, their poor water solubility and low oral bioavailability limit their antitumor effects in vivo. To address these issues, 37 triterpenoid acid derivatives linked to l-phenylalanine or l-proline were designed and synthesized in this study. Structure-activity relationship (SAR) studies found two promising glycyrrhetinic acid (GA) derivatives 11 and 16. Compound 11 was obtained by C3-OH esterification and C30-COOH modification with l-phenylalanine while 16 was obtained by attaching C3-OH with l-phenylalanine. Compounds 11 and 16 exhibit up to 48- and 120-fold improvement respectively compared with the IC50 values of naturally occurring GA in the cellular assay. Fluorescence microscope and flow cytometric analysis suggested that both compounds 11 and 16 increased the content of ROS and Ca2+ in cancer cells, decreased mitochondrial membrane potential (JC-1), and activated the regulator caspase-3/8/9 to trigger cell apoptosis. RNA-seq analysis and western blot analysis indicated that compounds 11 and 16 may promote apoptosis by upregulating the functions of pro-apoptotic factors while inhibiting the proteasome activity.

Developing a Novel Indium(III) Agent Based on Human Serum Albumin Nanoparticles: Integrating Bioimaging and Therapy.

To effectively integrate diagnosis and therapy for tumors, we proposed to develop an indium (In) agent based on the unique property of human serum albumin (HSA) nanoparticles (NPs). A novel In(III) quinoline-2-formaldehyde thiosemicarbazone compound (C5) was optimized with remarkable cytotoxicity and fluorescence to cancer cells in vitro. An HSA-C5 complex NP delivery system was then successfully constructed. Importantly, the HSA-C5 complex NPs have stronger bioimaging and therapeutic efficiency relative to C5 alone in vivo. Besides, the results of gene chip analysis revealed that C5/HSA-C5 complex NPs act on cancer cells through multiple mechanisms: inducing autophagy, apoptosis, and inhibiting the PI3K-Akt signaling pathway.

Developing a Novel Anticancer Gold(III) Agent to Integrate Chemotherapy and Immunotherapy.

To effectively treat gastric cancer, we innovatively attempted to develop a metal agent to integrate immunotherapy and chemotherapy by dual targeting the cellular components in the tumor microenvironment (TME) based on the specific residue of human serum albumin (HSA) nanoparticles (NPs). We synthesized a series of Au(III) α-N-heterocyclic thiosemicarbazone compounds and obtained a Au agent (5b) with remarkable cytotoxicity to gastric cancer cells; moreover, we successfully constructed a novel HSA-5b complex NP delivery system. Importantly, the in vivo results showed that 5b/HSA-5b NPs effectively inhibited gastric tumor growth and HSA-5b NPs enhanced the therapeutic efficiency, bioavailability, and targeting ability compared with those of 5b alone. Furthermore, the in vitro/in vivo results revealed that 5b/HSA-5b NPs could integrate chemotherapy and immunotherapy by synergistically attacking two different cellular components in TME at the same time, namely, polarizing the tumor-associated macrophages and inducing apoptosis of gastric cancer cells.

Developing a Novel Gold(III) Agent to Treat Glioma Based on the Unique Properties of Apoferritin Nanoparticles: Inducing Lethal Autophagy and Apoptosis.

Effective delivery of anticancer agents across the blood-brain barrier (BBB) required innovative strategies to achieve glioma regression. To resolve this problem, we proposed to develop a metal agent that target and treat glioma based on the unique property of apoferritin (AFt) nanoparticles (NPs). Thus, we synthesized a series of Au(III) 3-(4-metyl piperidine)thiosemicarbazides compounds and analyzed their structure-activity relationships, obtaining a Au agent (C6) with remarkable cytotoxicity in glioma. Moreover, we confirmed that C6 kills glioma cells by inducing lethal autophagy and apoptosis. Importantly, our results revealed that the successfully constructed apoferritin-C6 NPs (AFt-C6 NPs) can effectively cross the BBB, inhibit glioma growth, and selectively accumulate in tumors.

Synthesis of a series of novel In(III) 2,6-diacetylpyridine bis(thiosemicarbazide) complexes: structure, anticancer function and mechanism.

The anticancer function and anticancer mechanism of indium (In) complexes still remain mysterious to date. Furthermore, it is greatly challenging to design a multi-functional metal agent that not only kills cancer cells but also inhibits their invasion and metastasis. Thus, to develop novel next-generation anticancer metal agents, we designed and synthesized a series of novel In(iii) 2,6-diacetylpyridine bis(thiosemicarbazide) complexes (C1-C4) for the first time and then investigated their structure-activity relationships with human urinary bladder cancer (T-24) cells. In particular, C4 not only showed higher cytotoxicity to cancer cells and less toxicity toward normal cells relative to cisplatin but also inhibited cell invasion and metastasis of T-24 cells. Interestingly, C4 acted against T-24 cells exhibiting multiple mechanisms: (1) arresting the S-phase of cell cycle via regulation of cytokine kinases, (2) activating the mitochondrial-mediated apoptosis, endoplasmic reticulum-stress-mediated cell death, PERK and c-Jun N-terminal kinase 1 (JNK) cell signaling pathways, and (3) inhibiting the expression of telomerase via the regulation of c-myc and h-TERT proteins. Our results suggested that C4 may be developed as a potential multi-functional and multi-targeting anticancer candidate.

Human Serum Albumin-Based Dual-Agent Delivery Systems for Combination Therapy: Acting against Cancer Cells and Inhibiting Neovascularization in the Tumor Microenvironment.

To cause tumor regression by acting against cancer cells and inhibiting neovascularization in the tumor microenvironment, we constructed human serum albumin (HSA)-based delivery systems of 2-acetylpyridine-4,4-dimethyl-3-thiosemicarbazone-copper(II) [Cu(Ap44mT)]Cl and paclitaxel to improve both the therapeutic efficacy and the targeting ability in vivo. X-ray crystallography and matrix-assisted laser desorption/ionization time-of-flight mass spectra confirmed that [Cu(Ap44mT)]Cl complexed with HSA, whereas paclitaxel was tethered to the HSA complex by a linker sensitive to the active matrix metalloproteinase 2 (MMP2) protein. Up to 78% of paclitaxel was released from HSA within 2 h owing to MMP2 protein cleavage. In addition, a large amount of Cu(Ap44mT) was released from HSA in a pH 4.7 buffer. In vivo results revealed the following: (1) the tumor inhibitory rates of the HSA conjugate and the two-agent combination were 72.1 and 50.7%, respectively; (2) the inhibition rate of tumor angiogenesis of the HSA conjugate (73.3%) was higher than that of the two-agent combination (52.4%); (3) the increased amount of Cu in the tumor treated with the HSA conjugate was about 2-fold that in the tumor treated with the two-agent combination. Obviously, the HSA conjugate not only possessed a stronger capacity to inhibit neovascularization and the growth of liver tumors but also improved the targeting ability compared to the combination of the two agents alone.

Novel Brain-Tumor-Inhibiting Copper(II) Compound Based on a Human Serum Albumin (HSA)-Cell Penetrating Peptide Conjugate.

It is a great challenge to design drugs that penetrate the blood-brain barrier to inhibit brain tumor growth by acting against multiple targets and also improve their delivery efficacy and targeting ability to cancer cells. To overcome the above problems, we designed a multitarget metal agent for treating brain tumors based on an human serum albumin (HSA)-cell penetrating peptide conjugate. Thus, we rationally screened copper (Cu) and 2-acetyl-3-ethylpyrazine thiosemicarbazones to synthesize six compounds, and we investigated their structure-activity relationships and confirmed multiple mechanisms for brain glioma cells. The HSA-6b complex structure indicated that 6b binds to the IIA subdomain of HSA and His242 replaces the Br ligand in 6b in coordination with Cu2+. In vivo data suggested that both 6b and the HSA-6b-peptide conjugate penetrate the blood-brain barrier and inhibit brain tumor growth with few side effects. Furthermore, the HSA-peptide conjugate also improved the delivery efficacy and targeting ability of 6b in vivo.

Novel Pt(ii) complexes with modified aroyl-hydrazone Schiff-base ligands: synthesis, cytotoxicity and action mechanism.

To develop new anti-tumour Pt(ii) agents, we designed and synthesized five Pt(ii) complexes. These Pt(ii) complexes were modified benzene rings of 2-hydroxybenzylidene with a hydrocarbyl or halogen group. The five Pt(ii) complexes possessed remarkable cytotoxicity against tumour cells in vitro. In particular, we investigated chemotherapeutic mechanisms of the complexes against A549cisR cells. The Pt(ii) complexes could bind to and cleave DNA, while also inducing arrest of the cell cycle in S phase, leading to down-regulation of the levels of cyclin-dependent kinases and cyclin and up-regulation of the expression of p21. The selected complex, C3, changed the mitochondrial membrane potential and induced apoptosis. C3 also inhibited the expression of the c-myc gene and downstream proteins, thereby inhibiting telomerase activity.