Alterations of mitochondrial structure and function in tumor cells allow cell survival and proliferation under hypoxic and acidic microenvironment. The effect of normal mitochondria on tumor initiation and development remains unknown. In this study, mice were euthanized by rapid cervical dislocation for isolation of hepatic mitochondria, which were injected intravenously to melanoma-bearing mice. This animal experiment had been approved by Southwest University Experiment Animal Ethics Review Committee. The results showed that exogenous mitochondria can significantly inhibit the growth of melanoma. Mitochondria isolated from the liver of young mice had more potent anti-melanoma effect than those isolated from aging mice. The average volume of tumors decreased significantly from 1.35 cm³ to 0.34 cm³, and the average mass of tumors decreased significantly from 0.63 g to 0.22 g. This anti-tumor mechanism might be associated with induction of mitophagy and cell necrosis after the exogenous mitochondria entering the melanoma cells. As mitotherapy can clinically improve somatic cell survival for treatment of pediatric patients with myocardial ischemia, the observed anti-tumor effect of exogenous mitochondria provides a hope for selective tumor treatment.

The purpose of this study was to select the active compounds targeting Hsp90 protein in pancreatic cancer cells through a new dual "target + activity" rapid discovery technique. We combined an in vitro anti-cancer activity screening method with a dual-luciferase reporter gene and multi-chromatography separation technology, for rapid discovery of potential Hsp90 inhibitors from the Chinese herbal medicine Physalis angulata L. The anti-proliferation activity of those compounds was assessed in pancreatic cancer cell line BxPC-3 by MTT assays. The molecular mechanisms of Hsp90 inhibition were explored by Western blot and shRNA knockdown assays. As a result, two withanolides, withanolide E (WE) and 4β-hydroxywithanolide E (HWE), were identified from Physalis angulata L. The half maximal inhibitory concentration (IC₅₀) of WE and HWE were 0.71±0.03 and 1.23±0.10 μmol·L^-1 for the growth of BxPC-3 cells in 48 h. Luciferase reporter assay demonstrated that WE and HWE significantly induced heat shock element (HSE) activity in a dose-and time-dependent manner. The molecular mechanism study showed that after exposing to 5 μmol·L^-1 WE or HWE for 48 h, the aggregation of Hsp90 dimer was upregulated to 6.5±1.3 and 11.8±2.0 fold, while the expression of Hsp90 client protein Akt was downregulated to 21.7%±2.8% and 9.8%±1.4% of the control group. Moreover, the Hsp90 inhibitory activity of WE or HWE was canceled by shRNA mediated Hsp90 knockdown. Overall, based on the dual "target + active" rapid discovery technique, two new Hsp90 inhibitors WE and HWE were found from Physalis angulata L. The Hsp90 inhibitory mechanism of WE and HWE may be mediated by induction of Hsp90 aggregate dimer and inhibition of Hsp90 client protein Akt expression.

A sensitive and efficient liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for quantitative determination of diflucortolone in rabbit plasma after dermal administration of diflucortolone valerate cream to rabbits. After extraction with ethyl acetate, the chromatographic separation was performed on Zorbax Eclipse XDB-C18 (50 mm×4.6 mm, 5 μm) with a gradient mobile phase consisting of 50% acetonitrile-50% methanol and 0.1% formic acid-5% methanol-5 mmol·L^-1 ammonium formate at a flow rate of 0.35 mL·min^-1. The quantitative analysis was carried out using multiple reaction monitoring (MRM) at specific ion transitions of m/z[M+H]⁺ 395.2→m/z 355.2 for diflucortolone and m/z[M+H]⁺ 258.1→m/z 120.9 for ethoxyphenylethylamine (internal standard) in positive ion mode with electrospray ionization (ESI) source. This validated LC-MS/MS method had a linearity over the concentration range of 0.01-10 ng·mL^-1 with the lower limit of quantification (LLOQ) at 0.01 ng·mL^-1. At level of LLOQ, the inter and intra-assay precision (RSD) were no greater than 9.82% and 11.0%, respectively. The main pharmacokinetic parameters of the diflucortolone including t_max, C_max, AUC_{0-72 h}, and t_1/2 were as follows:(6.33±1.21) h, (0.168±0.080 0) ng·mL^-1, (3.15±0.834) h·ng·mL^-1, (32.0±17.4) h. The method was validated in the pharmacokinetic study of diflucortolone in rabbit following dermal administration of diflucortolone valerate cream at dose of 0.01 g·cm^-2. In this study, the program of animal testing had been approved by Committee on the management and usage of experimental animal in the Evaluation Company of Innovative Drug, Tianjin Institute of Pharmaceutical Research.

The purpose of this study is to further explore the effects of SI-4650, a newly discovered small molecule inhibitor of spermine oxidase (SMO) in our laboratory, on proliferation and migration of human osteosarcoma 143B cells and its underlying molecular mechanism. Chemiluminescence and high performance liquid chromatograph were used to analyze the effect of SI-4650 on SMO activity in 143B cells. DCFH-DA-staining/FCM was used to analyze the accumulation of cellular reactive oxygen species (ROS), whereas MTT and FCM were used to detect proliferation and cell cycle. Transwell culture and Western blot were used to analyze the expression levels of migration-related proteins. PI/FITC-Annexin V/FCM, fluorescence microscopy and Western blot were used to analyze apoptosis and autophagy. Our results showed that SI-4650 could significantly decrease SMO activity, inhibit cell proliferation or migration, and induce a S-phase cell cycle arrest in 143B human osteosarcoma cells. The mechanism may be related to interfering with polyamine metabolism, activating mitochondrial-mediated apoptosis and causing autophagic death. These results suggest that SI-4650 has the potential for clinical use in treatment of osteosarcoma.

Carbon monoxide (CO) is an important chemical gas messenger molecule in the body with anti-inflammatory activity. As an active substance in gaseous state, the method for its safe and effective delivery towards the lesion sites remains to be established. Based on the natural affinity of carbon monoxide to hemoglobin, a main component of red blood cells (RBCs), this study proposes a carbon monoxide-red blood cell (CO-RBC) composite system, and tested its therapeutic effect against lung injury in an animal model. The mouse model of septic lung injury was adopted, and the carbon monoxide release molecule (CORM-2) was used as a positive control. CO-RBC system was characterized by CO release, stability, toxicity and in vivo lung targeting. The expression of intercellular adhesion molecule (ICAM-1) and pulmonary surfactant protein-A (SP-A) were evaluated in the animal model and the therapeutic effect of CO-RBC system for sepsis was measured by inflammatory factors tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), as well as survival time of mice and pathological changes of the lung. Our results show that CO-RBC system exhibited satisfactory stability with negligible CO release during 48 h storage under nitrogen protection, while the CO release was about 70% within 12 h under physiological condition, in contrast to CO burst release from CORM-2. The CO-RBC system showed no significant toxicity in the animal model, and in vivo fluorescence imaging results showed effective accumulation in the lungs, supporting its lung targeting effects. The secretion of TNF-α and IL-6 in the CO-RBC group was significantly lower than that in other groups, the degree of pulmonary interstitial edema was relieved, the white blood cell infiltration was decreased, and the survival rate was significantly improved. Therefore, the CO-RBC system has a significant inhibitory effect on the pulmonary inflammatory response in septic mice compared with CORM-2. This system provides a new hope for therapeutic treatment of sepsis.

Covalent tyrosine kinase inhibitors (TKIs) can inhibit the signaling pathway of tumor cells by covalent binding with cysteine residues of target proteins, which has the advantages of high potency, extended duration of action and overcoming drug resistance. In this article, we will review the metabolism and pharmacokinetics of some covalent TKIs. Currently, the covalent TKIs approved by US food and drug administration (FDA) are afatinib, neratinib, dacomitinib, osimertinib, ibrutinib and acalabrutinib. Pyrotinib have been approved by National Medical Products Administration (NMPA) to reach the market recently. Covalent TKIs can covalently bind with plasma proteins, especially human serum albumin, thus effected the pharmacokinetics of these drugs.

Melatonin (MLT) is an endogenous chemical that has antitumor effects at high doses. However, it shows low oral bioavailability and short in vivo half-life, leading to drug resistance. Here, liposomal melatonin dry powder inhalers (LMD) were prepared, and were used for treatment of primary rat lung cancer by pulmonary delivery. Liposomal melatonin (LM) was prepared by the ethanol injection method to achieve an entrapment efficiency of 98.89%. LMD was obtained by freeze-drying after LM was mixed with mannitol. LMD appeared as spherical particles under a scanning electron microscope. The rehydrated liposomes had a small size of 65.15 nm and the zeta potential of -14.2 mV without change inentrapment efficiency. LMD had an aerodynamic particle size of 6.73 ±0.012 μm and a fine particle fraction (FPF < 8.06 μm) of 22.2%, suitable for pulmonary delivery. When administered with the same dose, LMD showed much higher inhibition on A549 lung cancer cells than MLT and gemcitabine. LMD of a large dose had no effect on the growth of normal lung epithelial cells (BEAS-2B). Rat lung cancer models were established after 45 days by instilling 3-methylcholanthrene (MCA) and N, N-dimethylnitrosamine (DEN) into the rat lungs once (the experiments had been approved by the ethics committee and carried out in accordance with relevant guidelines and regulations). Decreases of tumor nodules and inflammatory cells in the tumor-bearing rat lungs were observed after treatment of MLT, gemcitabine and LMD by pulmonary delivery compared with the models, wherein LMD was most effective. The efficiencies of inhibition of NF-κB p65, increase of Tunel detection (indicating enhancement of apoptosis), and decrease of malondialdehyde corresponded to LMD being most effective. Therefore, given the fact that LMD can deliver the drug into the tumor tissues of lungs, and it presents as a promising pulmonary inhalable regiment for treatment of lung cancer.

Reprogramming of metabolism is one of the most critical features in tumorigenesis and tumor growth. Many types of cancer show an increased demand for specific amino acids, rely on exogenous supplies, or alter amino acid metabolic pathways, leading to changes in corresponding amino acid levels to meet the need of tumorigenesis. Therefore, if the level of tumor growth-dependent amino acids can be effectively controlled, a new treatment strategy can be developed from the perspective of cell metabolism. At present, remarkable progress has been made in this field. This paper outlines the amino acid metabolic pathways closely related to tumorigenesis and tumor growth, and summarizes the corresponding regulatory mechanisms and active molecules. Finally, the direction of the field is discussed and prospected for future development.

As a part of novel drug delivery carriers, peptides have diverse biological activities, low immunogenicity and good biocompatibility. In recent years, studies on the delivery carriers modified by peptides have attracted much attention. Among them, the peptides with acid sensitivity can change their secondary structures under slightly acidic microenvironment of the tumor or in lysosome. Therefore, the carriers made or modified by acid-sensitive peptides can specifically release the loaded drug in the tumor tissue, enhance the cell internalization of drugs and improve its therapeutic effects. In accordance with acid-sensitive peptides studied, the side chains, number of polar residues, sequence and secondary structure of the peptides might be involved in the acid sensitivity. In this review, we summarize the acid-sensitive peptides from recent literatures, analyze the connection between the structure and the acid sensitivity, and focus on the mechanism and application of acid-sensitive peptides in drug delivery. This provides the basis for further development and utilization for acid-sensitive peptides for efficient drug delivery.

This study was designed to explore the interventional mechanism involving "multi-components, multi-targets and multi-pathways" of Gu-Chang-Zhi-Xie pills (GCZX) for treatment of irritable bowel syndrome (IBS) using pharmacological network technology. Firstly, 96 active ingredients from GCZX pills were screened by ADME parameter filtration and chemical space principal component analysis, and the targets of anti-IBS function were predicted using PharmMapper online database. Secondly, AutoDock Vina was used to validate the docking between the active ingredients and predicted disease targets, and to establish the corresponding relationship between "pharmacodynamic molecules and target proteins". Finally, the target elements were mapped into the KEGG biological pathway by CluoGO plug-in, which further elucidates the potential relationship between the key targets and the mechanism of action of Gu-Chang-Zhi-Xie pills for treatment of IBS. The results showed that most of the top 11 key pharmacodynamic molecules were isoquinoline alkaloids, which mainly acted on inflammatory or pain targets, with different degrees of anti-inflammatory and analgesic effects. A total of 39 key targets were identified, including TPH1, TNF-α, IL-6, IFN-γ, MAO-A and IL-10. These targets were mapped to 29 KEGG pathways, of which the P-value of 5-HT signaling pathway was the smallest. Therefore, the pharmacodynamic molecules mainly act on 6 core targets and may play a major role in the regulation of 5-HT signal synthesis or transport pathway. This study sets an example for drug development and mechanistic investigation using innovative technology.