[Research progress in macrophage migration inhibitory factor (MIF) in tumor immune response].

Macrophage migration inhibitor factor (MIF), as a pro-inflammatory and oncogenic cytokine, is highly expressed in a variety of malignant tumors and recruits tumor cells or immune cells into the tumor microenvironment. MIF affects the development of tumor by altering the tumor microenvironment. In the process of tumor, MIF not only plays an anti-inflammatory role, but also promotes tumorigenesis by immune escape and immune tolerance.This is closely related to immune cells that play a role in the tumor immune response, mainly including natural killer (NK) cells, macrophages, dendritic cells, B cells, T cells and myeloid-derived suppressor cells. The article summarizes the role of MIF in tumor immune and the relationship between MIF and the development of malignant tumors, in order to provide new ideas and possible therapy for tumor treatment.

Fisetin-induced cell death in human ovarian cancer cell lines via zbp1-mediated necroptosis.

BACKGROUND: Among reproductive cancers, ovarian cancer leads to the highest female mortality rate. Fisetin, a natural flavonoid, exerts pharmacological effects, inhibiting cancer growth with various origins. Although multiple mechanisms are involved in regulating cell death, it is still unclear whether and how fisetin exhibits anticancer effects on ovarian cancer. The present study aimed to evaluate cell apoptotic and necroptotic processes occurring in ovarian carcinoma (OC) cell lines induced by fisetin. METHODS: Cell growth was evaluated by MTT assay in OC cell lines treated with or without fisetin. Annexin V/propidium iodide staining followed by flow cytometry was used to characterize fisetin-induced cell death. The apoptotic process was suppressed by z-VAD intervention, and cell necroptosis was assessed by introducing ZBP1-knockdown OC cell lines coupled with fisetin intervention. The expression of necroptosis-related mediators and the migration capability of the respective cells were evaluated by Western blotting and in vitro cell invasion assay. RESULT: Fisetin successfully reduced cell growth in both OC cell lines in a dose-dependent manner. Both apoptosis and necroptosis were induced by fisetin. Suppression of the cell apoptotic process failed to enhance the proliferation of fisetin-treated cells. The induced cell death and robust expression of the necroptotic markers RIP3 and MLKL were alleviated by knocking down the expression of the ZBP1 protein in both OC cell lines. CONCLUSION: The present study provided in vitro evidence supporting the involvement of both apoptosis and necroptosis in fisetin-induced OC cell death, while ZBP1 regulates the necroptotic process via the RIP3/MLKL pathway.

Ribosomal L1 domain-containing protein 1 coordinates with HDM2 to negatively regulate p53 in human colorectal Cancer cells.

BACKGROUND: Ribosomal L1 domain-containing protein 1 (RSL1D1) is a nucleolar protein that is essential in cell proliferation. In the current opinion, RSL1D1 translocates to the nucleoplasm under nucleolar stress and inhibits the E3 ligase activity of HDM2 via direct interaction, thereby leading to stabilization of p53. METHODS: Gene knockdown was achieved in HCT116p53+/+, HCT116p53-/-, and HCT-8 human colorectal cancer (CRC) cells by siRNA transfection. A lentiviral expression system was used to establish cell strains overexpressing genes of interest. The mRNA and protein levels in cells were evaluated by qRT-PCR and western blot analyses. Cell proliferation, cell cycle, and cell apoptosis were determined by MTT, PI staining, and Annexin V-FITC/PI double staining assays, respectively. The level of ubiquitinated p53 protein was assessed by IP. The protein-RNA interaction was investigated by RIP. The subcellular localization of proteins of interest was determined by IFA. Protein-protein interaction was investigated by GST-pulldown, BiFC, and co-IP assays. The therapeutic efficacy of RSL1D1 silencing on tumor growth was evaluated in HCT116 tumor-bearing nude mice. RESULTS: RSL1D1 distributed throughout the nucleus in human CRC cells. Silencing of RSL1D1 gene induced cell cycle arrest at G1/S and cell apoptosis in a p53-dependent manner. RSL1D1 directly interacted with and recruited p53 to HDM2 to form a ternary RSL1D1/HDM2/p53 protein complex and thereby enhanced p53 ubiquitination and degradation, leading to a decrease in the protein level of p53. Destruction of the ternary complex increased the level of p53 protein. RSL1D1 also indirectly decreased the protein level of p53 by stabilizing HDM2 mRNA. Consequently, the negative regulation of p53 by RSL1D1 facilitated cell proliferation and survival and downregulation of RSL1D1 remarkably inhibited the growth of HCT116p53+/+ tumors in a nude mouse model. CONCLUSION: We report, for the first time, that RSL1D1 is a novel negative regulator of p53 in human CRC cells and more importantly, a potential molecular target for anticancer drug development.

Synthesis, characterization, DNA/HSA interactions and in vitro cytotoxic activities of two novel water-soluble copper(II) complexes with 1,3,5-triazine derivative ligand and amino acids.

Two water-soluble copper(II) complexes of 6-(pyrazin-2-yl)-1,3,5-triazine-2,4-diamine (pzta) and amino acids, [Cu(pzta)(L-ArgH)(H2O)](ClO4)2 (1) and [Cu(pzta)(L-Met)(H2O)]ClO4·3H2O (2) (L-ArgH: protonated L-Argininate; L-Met: L-Methioninate), were synthesized and characterized. The determined X-ray crystallographic structures of 1 and 2 exhibited distorted square-pyramidal coordination geometries. Their binding properties toward calf thymus DNA (CT-DNA) and human serum protein (HSA) were measured by spectroscopic (UV-Vis, fluorescence, circular dichroism (CD)), calorimetric (isothermal titration calorimetry (ITC)) and molecular docking technology. DNA binding experiments showed that the complexes bound to DNA through a groove binding mode, the positive ΔH and ΔS values indicated that the hydrophobic interaction was the main force in the binding between the complexes and DNA. Besides, the complexes caused the fluorescence quenching of HSA through a static quenching procedure, changed the secondary structure and microenvironment of the Trp-214 residue, and preferably bound to subdomain IIA of HSA driven by hydrophobic and hydrogen-bond interactions. These results were further verified by the molecular docking technology. Furthermore, the in vitro cytotoxicities of the complexes against three human carcinoma cell lines (A549, PC-3 and HeLa) were evaluated, which confirmed that the complexation improved the anticancer activity of the pzta ligand significantly.

Two new Cu(II) dipeptide complexes based on 5-methyl-2-(2'-pyridyl)benzimidazole as potential antimicrobial and anticancer drugs: Special exploration of their possible anticancer mechanism.

In the search for more effective anticancer drugs with less toxic side effects, dipeptides were introduced into the Cu(II) complex of 5-methyl-2-(2'-pyridyl)benzimidazole (HPBM). Analytical and spectroscopic techniques were employed to thoroughly characterize complexes [Cu(Gly-gly)(HPBM)(H2O)]ClO4·0.5H2O (1) and [Cu(Gly-L-leu)(HPBM)(H2O)]ClO4 (2) (where Gly-gly = Glycyl-glycine anion, Gly-L-leu = Glycyl-l-leucine anion). The solution stability studies performed by ultraviolet-visible (UV-Vis) spectroscopy confirmed the stability of the complexes in the buffer solutions. The DNA binding affinity was evaluated using multi-spectroscopy, viscosity measurement and molecular docking methods and further quantified by Kb and Kapp values, revealing an intercalative mode. Moreover, gel electrophoresis analysis revealed that the complexes could damage CT DNA through a hydroxyl radical pathway in the presence of ascorbic acid. All the complexes displayed favorable antimicrobial and cytotoxic activities toward the tested microorganisms (Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa) and cancer cells (A549, HeLa and PC-3). Most importantly, the possible anticancer mechanism of the complexes was explored by determining the cells morphological changes, intracellular reactive oxygen species (ROS) levels, location in mitochondria, mitochondrial membrane potentials and the expression of Bcl-2 family proteins. The results showed that the complexes could induce apoptosis in HeLa cells through an ROS-mediated mitochondrial dysfunction pathway, which was accompanied by the regulation of Bcl-2 family proteins.