Objective　To investigate the indomethacin (IN) induced apoptosis of K562 cells: ① the expression, activation and subcellular localization of caspase-3 and -8;②the change of intracellular free calcium concentration (［fCa2+］i) and its mechanism; and ③ whether the cell apoptosis is cyclooxygenase (cox) dependent or not. Methods　Changes and subcellular localization of caspase-3 and -8 were observed by laser scanning confocal microscopy (LSCM); expression and activation of caspase-3 and -8 proteins by Western blotting; changes of intracellular ［fCa2+］i by LSCM coupling with a calcium-fluorescence probe and calcium chelator EGTA blocking test; and cox inhibitor effect by MTT assay. Results　①LSCM assay and Western blotting showed that caspase-3 and -8 localized in cytoplasm and nucleus dispersedly and spottedly and were upregulated with the increasing of IN doses. Western blotting also showed the cleavage and activation of caspase-3 and -8 during IN-induced apoptosis. ②The increase of ［fCa2+］i in K562 cells was parallel to the increase of IN concentration regardless of the presence or absence of EGTA. But with EGTA treatment,［fCa2+］i was much less than that without EGTA treatment. ③Low dose of IN or other cox inhibitors could not exert cytotoxic effects on K562 cells whereas high dose of IN could. Conclusion　①The upregulation and activation of caspase-3 and -8 play a fundamental role in apoptosis induced by IN in K562 cells. Both cytoplasm and nucleus are locations where caspase-3 and -8 localized. ②The increase of ［fCa2+］i may be critical in the modulation of apoptosis; the extracellular calcium influx is the main source of the elevation of ［fCa2+］i in K562 cells and can be blocked by the calcium chelator EGTA;the release of calcium from intracellular calcium store is also an important source of the intracellular calcium which can trigger apoptosis without the extracellular calcium influx.③Apoptosis of K562 cells induced by IN is cox-independent.

To establish a green fluorescent protein (GFP)-based cellular model for screening proteasome inhibitors from compounds including extracts from Traditional Chinese Medicinal herbs, we transfected A549 cells with lentivirus expression vector pGC-E1-ZU1-GFP, and selected clones stably expressing ZU1-GFP. The A549-ZU1-GFP cells were treated with PS-341 for 24 h, and the accumulation of GFP was analyzed by fluorescence microscope. We found that the fluorescence intensity of A549-ZU1-GFP cells treated with PS-341 was significantly increased as compared to the control. We screened for proteasome inhibitors from compounds including some from Traditional Chinese Medicinal herbs, and the data suggested a few compounds could be novel proteasome inhibitors.
Boronic Acids ; pharmacology ; Bortezomib ; Cell Line ; Drug Evaluation, Preclinical ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Genetic Vectors ; genetics ; Green Fluorescent Proteins ; biosynthesis ; genetics ; Humans ; Lentivirus ; genetics ; metabolism ; Models, Biological ; Protease Inhibitors ; isolation & purification ; pharmacology ; Pyrazines ; pharmacology

Effects of Rabdocoetsin B (Rabd-B), a diterpenoid extracted from Isodon coetsa, on t(8;21) leukemic cells was tested by CCK-8 assay and Flow cytometry. The A549 cells stably expressing pGC-E1-ZU1-GFP were treated with Rabd-B for 4 h, and the accumulation of GFP was detected by fluorescence microscope. Using Western blotting, we investigated the expression of Casp-3, PARP, S6', which is a subunit of the 19S regulatory complex of the 26S proteasome, and cellular ubiqutinated proteins. We found that Rabd-B induced growth inhibition and apoptosis of Kasumi-1 cells in a dose-dependent manner. In Kasumi-1 cells treated with 2.5 micromol/L Rabd-B for 24 h, pro-caspase-3 was processed into its active form. The substrate of Casp-3, poly ADP-ribose polymerase (PARP), was cleaved with generation of an 85 kD fragment. The increased GFP fluorescence intensity, cleavage of S6' and the accumulation of ubiquitinated proteins were found in Kasumi-1 cells treated with Rabd-B. These results suggested that Rabd-B is a potential proteasome inhibitor which induces programmed cell death of t(8;21) cells. Further study might provide evidence for employing Rabd-B in treating human t(8;21) leukemia.
Antineoplastic Agents, Phytogenic ; pharmacology ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cell Line, Tumor ; Diterpenes ; isolation & purification ; pharmacology ; Humans ; Isodon ; chemistry ; Leukemia, Myeloid, Acute ; pathology ; Proteasome Inhibitors ; Translocation, Genetic ; Ubiquitins ; metabolism

Recently, Ng et al. reported that the A:T > T:A substitutions, proposed to be a signature of aristolochic acid (AA) exposure, were detected in 76/98 (78%) of patients with hepatocellular carcinoma (HCC) from the Taiwan Province of China, and 47% to 1.7% of HCCs from the Chinese mainland and other countries harbored the nucleotide changes. However, other carcinogens, e.g., tobacco carcinogens 4-aminobiphenyl and 1,3-butadiene, air toxic vinyl chloride and its reactive metabolites chloroethylene oxide, melphalan and chlorambucil, also cause this signature in the genome. Since tobacco smoke is a worldwide public health threat and vinyl chloride distributes globally and is an air pollutant in Taiwan Province, the estimation of the patients' exposure history is the key to determine the "culprit" of the A:T > T:A mutations. Apparently, without estimation of the patients' exposure history, the conclusion of Ng et al. is unpersuasive and misleading.
Aristolochic Acids ; toxicity ; Carcinogens ; toxicity ; Carcinoma, Hepatocellular ; chemically induced ; genetics ; China ; Environment ; Humans ; Liver Neoplasms ; chemically induced ; genetics ; Mutation ; Taiwan ; Tobacco ; toxicity ; Vinyl Chloride ; toxicity

In order to unveil ubiquitin pathway genes (UPGs) that are essential for non-small cell lung cancer (NSCLC) cell proliferation, we recently conducted a siRNA screening experiment to knockdown the expression of 696 UPGs found in the human genome in A549 and H1975 NSCLC cells. We found that silencing of one of the candidates, RFWD3 that encodes an E3 ubiquitin ligase essential for the repair of DNA interstrand cross-links in response to DNA damage, led to dramatic inhibition of NSCLC cell proliferation with significant Z-scores. Knockdown of RFWD3 suppressed colony forming activity of NSCLC cells.We further evaluated the significance of RFWD3 in NSCLCs and found that this gene was more elevated in tumor samples than in paired normal lung tissues and was inversely associated with the clinical outcome of patients with NSCLC. Moreover, RFWD3 expression was significantly higher in smokers than in non-smokers. These results show for the first time that RFWD3 is required for NSCLC cell proliferation and may have an important role in lung carcinogenesis.

Lung squamous cell carcinoma (LUSC) causes approximately 400 000 deaths each year worldwide. The occurrence of LUSC is attributed to exposure to cigarette smoke, which induces the development of numerous genomic abnormalities. However, few studies have investigated the genomic variations that occur only in normal tissues that have been similarly exposed to tobacco smoke as tumor tissues. In this study, we sequenced the whole genomes of three normal lung tissue samples and their paired adjacent squamous cell carcinomas.We then called genomic variations specific to the normal lung tissues through filtering the genomic sequence of the normal lung tissues against that of the paired tumors, the reference human genome, the dbSNP138 common germline variants, and the variations derived from sequencing artifacts. To expand these observations, the whole exome sequences of 478 counterpart normal controls (CNCs) and paired LUSCs of The Cancer Genome Atlas (TCGA) dataset were analyzed. Sixteen genomic variations were called in the three normal lung tissues. These variations were confirmed by Sanger capillary sequencing. A mean of 0.5661 exonic variations/Mb and 7.7887 altered genes per sample were identified in the CNC genome sequences of TCGA. In these CNCs, C:G→T:A transitions, which are the genomic signatures of tobacco carcinogen N-methyl-N-nitro-N-nitrosoguanidine, were the predominant nucleotide changes. Twenty five genes in CNCs had a variation rate that exceeded 2%, including ARSD (18.62%), MUC4 (8.79%), and RBMX (7.11%). CNC variations in CTAGE5 and USP17L7 were associated with the poor prognosis of patients with LUSC. Our results uncovered previously unreported genomic variations in CNCs, rather than LUSCs, that may be involved in the development of LUSC.
Adult ; Aged ; Aged, 80 and over ; Biomarkers, Tumor ; genetics ; Carcinoma, Squamous Cell ; genetics ; Case-Control Studies ; Female ; Genome, Human ; Genomic Structural Variation ; Humans ; Lung Neoplasms ; genetics ; Male ; Middle Aged ; Mutation

Since the outbreak of the COVID-19 pandemic in early December 2019, 81 174 confirmed cases and 3242 deaths have been reported in China as of March 19, 2020. The Chinese people and government have contributed huge efforts to combat this disease, resulting in significant improvement of the situation, with 58 new cases (34 were imported cases) and 11 new deaths reported on March 19, 2020. However, as of March 19, 2020, the COVID-19 pandemic continues to develop in 167 countries/territories outside of China, and 128 665 confirmed cases and 5536 deaths have been reported, with 16 498 new cases and 817 new deaths occurring in last 24 hours. Therefore, the world should work together to fight against this pandemic. Here, we review the recent advances in COVID-19, including the insights in the virus, the responses of the host cells, the cytokine release syndrome, and the therapeutic approaches to inhibit the virus and alleviate the cytokine storm. By sharing knowledge and deepening our understanding of the virus and the disease pathogenesis, we believe that the community can efficiently develop effective vaccines and drugs, and the mankind will eventually win this battle against this pandemic.
Betacoronavirus ; China ; epidemiology ; Coronavirus Infections ; epidemiology ; therapy ; Humans ; Pandemics ; Pneumonia, Viral ; epidemiology ; therapy

Humans ; COVID-19 ; China/epidemiology*

BACKGROUND: Immune checkpoint inhibitors (ICIs) such as antibodies against programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1), have shown remarkable efficacies in many subtypes of cancers. However, ICIs may also cause severe immune-related adverse events in the recipient patients. Recently, ICI-associated myocarditis have been reported in hundreds of patients worldwide, with a mortality rate of approximately 50% in these cases. This study aims to recapitulate the cardiotoxicity and explore the detoxicifying approaches to attenuate mortality caused by PD-1/PD-L1 inhibitors in healthy mice. METHODS: Six to eight-week-old C57BL/6 mice were inoculated with anti-PD-1 antibody (12.5 μg/g every 5 days for 6 injections), anti-PD-L1 antibody (10 μg/g once a week for 6 weeks), anti-PD-L1 antibody (with the same dosage described above) in combination with levothyroxine (0.25 μg/g, intraperitoneally injected half an hour before anti-PD-L1 antibody injection), or isotype control immunoglobulin IgG (10 μg/g once a week for 6 weeks). The ejection function of the hearts was detected by echocardiography, body temperature and blood pressure were detected by Mouse MonitorTM and non-invassive blood pressure minotor, and serum free thyroxine concentration was detected by The enzyme linked immunosorbent assay (ELISA). RESULTS: PD-L1 was expressed at different levels by the cardiomyocytes of the mice. The isotype control immunoglobulin and anti-PD-1 antibody did not cause death of the mice. The 12 mice receiving 3-6 injections of anti-PD-L1 antibody showed a significant increase in the heart-to-tibial ratio and cardiomyoctye degeneration, hyalinization and extravascular inflammatory cell infiltration. In addition, the serum thyroxine was mardedly decreased to 1/3 of that in the control group mice, and the blood pressure and body temperature were abnormally decreased in mice upon treatment with PD-L1 blockade. Eight of the 12 (66.7%) mice died from multiple intravenous injection of anti-PD-L1 antibody.Intraperitoneal injection of levothyroxine 30 min before the injection of anti-PD-L1 antibody significantly attenuated the mortality rate of the anti-PD-L1 antibody-treated mice. CONCLUSIONS The anti-PD-L1 antibody is cardiotoxic and lethal, and levothyroxine is able to rescue the mice from this immune checkpoint inhibitor-caused mortality.

Sialic acid binding Ig-like lectin 10 (Siglec10) is a member of innate immune checkpoints that inhibits the activation of immune cells through the interaction with its ligand CD24 on tumor cells. Here, by analyzing public databases containing 64 517 patients of 33 cancer types, we found that the expression of Siglec10 was altered in 18 types of cancers and was associated with the clinical outcomes of 11 cancer types. In particular, Siglec10 was upregulated in patients with kidney renal clear cell carcinoma (KIRC) and was inversely associated with the prognosis of the patients. In 131 KIRC patients of our settings, Siglec10 was elevated in the tumor tissues of 83 (63.4%) patients compared with that in their counterpart normal kidney tissues. Moreover, higher level of Siglec10 was associated with advanced disease (stages III and IV) and worse prognosis. Silencing of CD24 in KIRC cells significantly increased the number of Siglec10-expressing macrophages phagocytosing KIRC cells. In addition, luciferase activity assays suggested that Siglec10 was a potential target of the transcription factors c-FOS and GATA1, which were identified by data mining. These results demonstrate that Siglec10 may have important oncogenic functions in KIRC, and represents a novel target for the development of immunotherapies.
Carcinoma, Renal Cell/pathology* ; Gene Expression Regulation, Neoplastic ; Humans ; Immunity, Innate ; Kidney Neoplasms/pathology* ; Lectins/metabolism* ; Prognosis ; Receptors, Cell Surface/metabolism*