OBJECTIVE Gastric cancer is one of the most common malignant tumors,and the inci-dence rate is the highest in all kinds of tumors in China. However,it remains unclear that how signifi-cantly gastric cells are dependent on glycolysis,and which type of gastric cells are sensitive to glycolysis inhibition. In this study, several kind of gastric cancer cell lines were used as the research object, and the metabolic characteristics of different cell lines were systematically analyzed to provide theoretical support for the accurate treatment of gastric cancer. METHODS We examined the energy metabolism of four gastric cancer cell lines(MGC-803,SGC-7901,HGC-27 and BGC-823)by using glycolysis inhibitor, 2-deoxy-D-glucose(2-DG)and inhibitor of oxidative phosphorylation,oligomycin.Oxygen consumption rates(OCR)and L-lactate were also measured with an XF96 Analyzer(Seahorse Biosciences)to deter-mine the significance of metabolism of oxidative phosphorylation and aerobic glycolysisin gastric cells. In addition, western blot was used to detect the contribution of AMP-activated protein kinase (AMPK), and anti-apoptotic proteins(Bcl-2 and survivin)to clarify the mechanism of death or survival of gastric cancer cells treated by 2-DG or oligomycin. RESULTS In this study, it was shown that the growth of gastric cell lines were suppressed by 2-DG.However,the sensitivity to 2-DG was quite different among cell lines:IC 50 of 2-DG was from 3.28 mmol·L-1(MGC-803)to 15.57 mmol·L-1(BGC-823).MGC-803 was relatively sensitive to 2-DG (IC 50:3.28 mmol·L-1), consumed more glucose and produced more lactate (waste product of glycolysis) than the three other cell lines. Consequently, MGC-803 could be more dependent on glycolysis than other cell lines, which was further confirmed by the fact that glucose (+)FCS(-)medium showed more growth and survival than glucose(-)FCS(+)medium.Alternatively, BGC-823, most resistant to 2-DG (IC50: 15.57 mmol·L- 1), was most sensitive to oligomycin, and showed more growth and survival in glucose(-)FCS(+)medium than in glucose(+)FCS(-)medium. Thus,we had reasons to think BGC-823 cells depended on oxidative phosphorylation for energy production. In BGC-823,AMPK,which is activated when ATP becomes limiting,was rapidly phosphorylated by 2-DG, and expression of Bcl-2 was augmented,which might result in resistance to 2-DG.Interestingly,AMPK phosphorylation and augmentation of Bcl-2 expression by 2-DG were not observed in MGC-803,which is 2-DG sensitive. CONCLUSION There is a large metabolic difference between gastric cancer cell lines,which will facilitate the future gastric cancer therapy by targeting metabolic pathways.

OBJECTIVE To probe into the anti-esophagus cancer activity and mechanisms of DN3, a novel natural diterpenoid derivative. METHODS The anti-tumor activity in vitro of DN3 was evaluated by MTT, and by using human esophageal carcinoma cells xenografted into athymic mice model in vivo. The specific mechanisms of DN3, as a dual inhibitor of glycolysis and oxidative phos-phorylation(OXPHOS)were explored through cell and molecular biology techniques.For instance,the manner of cancer cell death induced by DN3 was characterized by hoechst33342, FITC-Annexin V/PI staining and flow cytometric analysis,then these changes of glucose consumption,glucose uptake and lactate production in glycolysis, as well as oxygen consumption rate (OCR) and ATP content in OXPHOS caused by DN3 were performed separately through related kits and SeahorseBioscience XF24 Extra-cellular Flux Analyzer.Furthermore,in order to obtain a clear understanding of the inhibition of DN3 to glycolysis and OXPHOS, these regulatory factors were investigated by Western blot, such as PI3K/AKT, c-Myc and p53 of glycolysis, Bax and HK2 of mitochondrial function. RESULTS DN3 inhibited the growth of esophagus cancer cell EC9706, EC109 and EC1 cells in a dose and time dependent manner,but showed no significant effects on human esophageal epithelial cells(HEECs).DN3 caused significant G2/M arrest of esophagus cancer cell lines and induced apoptosis of these cell lines, which indicated DN3 inhibited the growth of esophagus cancer cell through blocking cell cycle and inducing apoptosis in a dose and time-dependent manner. Importantly, 8 μM DN3 decreased the extracellular acidification rate (ECAR) by 45% in EC109, which indicated glycolysis was inhibited by DN3. Mean-while, DN3 decreased the oxygen consumption rate (OCR) and the OCR linked to intracellular ATP production in EC109 cells,but that was not obvious in HEECs,so which indicated that DN3 could selec-tively block OXPHOS of cancer cells. In addition, the accumulation of reactive oxygen species (ROS) and the drop of mitochondrial membrane potential (MMP) were also observed in EC109 incubated by DN3,which suggested mitochondrial biological function was disturbed.Furthermore,the expression of PI3K/AKT, c-Myc and HK2 related to glycolysis were down-regulated by DN3, but the p53 and Bax were up-regulated in esophageal carcinoma cells. The changes of these enzymes accounted for the decreased glycolysisand OXPHOS in esophageal carcinoma cells treated by DN3. CONCLUSION The new compound DN3 has a strong anti-esophageal carcinoma activity,and it is tolerable that DN3 is seen as a dual inhibitor of glycolysis and oxidative phosphorylation.

OBJECTIVE To study the anti-tumor activity and molecular mechanism of natural diter-pene derivative JD20 in vitro. METHODS Screening the sensitive of gastric carcinoma cell lines to JD20 by cytotoxicity test for 24 h.Cell morphology was evaluated by using DAPI.After staining of can-cer cells with PI or annexin V-FITC/PI respectively,the cell cycle and apoptosis induced by JD20 were detectded by flow cytometry. The change in cell membrane potential was detected by JC-1 test kit. Western blot method was used to detect the apoptosis-related protein. RESULTS The novel natural kaurane diterpene derivative JD20 had a significant inhibitory effect on tumor cells and was particularly active on gastric cancer cell lines HGC-27 (IC50=4.72 ± 1.37 μmol·L- 1) and MGC-803 (IC50=7.36 ± 0.86 μmol·L-1).Further studies found that JD20 resulted in thecell cycle arrest in the G2/M phase,and induced a significant apoptosis in HGC-27. In addition, JD20 also caused the drop of mitochondrial membrane potential of HGC-27 within a short time (3 h). Furthermore, the Western blotting analysis showed that JD20 could induce the up-regulation of p53,Bax and Bim protein expression in gastric can-cer cells,and the releasing of cytochrome c from the mitochondria into the cytoplasm,as well as the ac-tivation of casepase-9/3.CONCLUSION The natural kaurane diterpene derivative JD20 can inhibit the proliferation of various human cancer cells by blocking the cell cycle and inducing apoptosis, and its mechanism of inducing apoptosis may be related to the mitochondria-mediated apoptosis pathway.

Objective:To analyze the characteristics of new cases of pneumoconiosis in Yantai from 2010 to 2019, and to provide scientific basis for the prevention and control of pneumoconiosis.Methods:In March 2020, 2575 new pneumoconiosis cases in Yantai City from January 1, 2010 to December 31, 2019 were obtained through the "Health Hazard Information Monitoring System" platform under "China Disease Prevention and Control Information System" and patient hospital files. Excel 2007 was used to sort out the database of pneumoconiosis and analyze the epidemiological characteristics of new pneumoconiosis, including gender, age, length of service, type of work, etc.Results:From 2010 to 2019, the majority of new pneumoconiosis cases were male (2542 cases, 98.72%) , and the age of onset was 40-<60 years old (2074 cases, 80.54%) . The main age of onset was 15-<30 years (1534 cases, 59.57%) . Silicosis was the most common type of new pneumoconiosis (2313 cases, 89.83%) . There were 2262 cases (87.84%) with one stage of pneumoconiosis. The main types of work were rock driller (799 cases, 31.03%) , hauler (797 cases, 30.95%) , other mine workers (391 cases, 15.18%) . The economic type of enterprises was mainly state-owned enterprises (1156 cases, 44.89%) . The scale of enterprises mainly concentrated in large enterprises (1897 cases, 73.67%) .Conclusion:The new pneumoconiosis in Yantai City shows obvious concentration of disease and work types.It is necessary to strengthen the prevention and treatment of silicosis and the training of protection knowledge for rock drillers and transport workers.

Objective:To study the clinical efficacy of sequential glucocorticoids in the treatment of acute mercury poisoning complicated with interstitial pneumonia.Methods:Retrospective analysis of 37 patients with acute mercury poisoning complicated with interstitial pneumonia admitted from January 2009 to April 2019, including the sequential treatment group (15 cases) and the conventional treatment group (22 cases) , all patients were treated with sodium dimercaptopropane sulfonate, and given anti-inflammatory, liver-protecting and other drugs for symptomatic treatment. The conventional treatment group was given methylprednisolone 1mg/kg once a day for 5-7 days. The sequential treatment group was given 1 mg/kg of methylprednisolone once a day for 5-7 days, then gradually reduced to 20 mg, and the total course of treatment was 14-21 days. To observe the changes of clinical symptoms, signs, lung function including forced vital capacity (FVC) , forced expiratory volume in the first second (FEV 1) and ratio of forced expiratory volume in the first second to forced vital capacity (FEV 1/FVC) , and chest CT indexes before and after treatment in the two groups. Results:The clinical symptoms and signs of the two groups were significantly improved compared with those before treatment, and there was no significant difference between the apparent efficiency and the total effective rate of the two groups ( P>0.05) . The FVC, FEV 1, and FEV 1/FVC of the two groups were significantly higher than those before treatment. After treatment, the indexes of the sequential treatment group were significantly higher than that of the conventional treatment group, and the difference was statistically significant ( P<0.05) . The apparent efficiency (93.3%, 14/15) of CT lesions in the sequential treatment group was significantly higher than those of the conventional treatment group (59.1%, 13/22) , and the difference was statistically significant ( P< 0.05) . Conclusion:Sequential glucocorticoid treatment of acute mercury poisoning complicated with interstitial pneumonia could improve the effect of clinical signs and symptoms which is equal to conventional treatment, but it could better promote the recovery of lung function and the absorption of lung lesions.

Objective:To analyze the incidence characteristics of occupational chronic benzene poisoning under two diagnostic criteria.Methods:In March 2020, 126 patients who were divided into the old criteria group (74 cases) and the new criteria group (52 cases) were retrospectively analyzed. These patients were diagnosed with occupational chronic benzene poisoning, and were diagnosed in our hospital during the period of January 2009 to December 2019. The gender composition, age of onset, years of benzene exposure, industry distribution, work type, benzene concentration in working environment and diagnostic grade of the two groups of patients were analyzed and compared. The follow-up of 22 benzene poisoning observation subjects under the old criteria were retrospectively analyzed.Results:There were no statistically significant differences in gender composition, age of onset, years of benzene exposure, industry distribution and work type between the old criteria group and the new criteria group ( P>0.05) . In the old criteria group and the new criteria group, 41.9% (31/74) and 17.3% (9/52) of the patients' workplace benzene concentration exceeded the maximum allowable concentration, respectively. The composition of different benzene concentration in the workplace between the two groups showed statistically significant ( P<0.05) . In the old criteria group, the proportion of mild poisoning (79.7%, 59/74) was the majority, while in the new criteria group, the proportion of moderate and severe poisoning (51.9%, 27/52) were the majority, and there was statistically significance in the composition ratio of diagnostic grade between the two groups ( P<0.05) . Under the old criteria, after folow-up of 22 cases of benzene poisoning observation subjects, we observed that 8 cases (36.4%) progressed to the level of chronic benzene poisoning. Conclusion:The revision of diagnostic criteria for benzene poisoning may affect the composition of diagnosis classification. Based on the rights and interests of workers, formulating more complete diagnostic criteria and system policies will be more conducive to the development of occupational benzene poisoning prevention and control.

Objective:To analyze the characteristics of new cases of pneumoconiosis in Yantai from 2010 to 2019, and to provide scientific basis for the prevention and control of pneumoconiosis.Methods:In March 2020, 2575 new pneumoconiosis cases in Yantai City from January 1, 2010 to December 31, 2019 were obtained through the "Health Hazard Information Monitoring System" platform under "China Disease Prevention and Control Information System" and patient hospital files. Excel 2007 was used to sort out the database of pneumoconiosis and analyze the epidemiological characteristics of new pneumoconiosis, including gender, age, length of service, type of work, etc.Results:From 2010 to 2019, the majority of new pneumoconiosis cases were male (2542 cases, 98.72%) , and the age of onset was 40-<60 years old (2074 cases, 80.54%) . The main age of onset was 15-<30 years (1534 cases, 59.57%) . Silicosis was the most common type of new pneumoconiosis (2313 cases, 89.83%) . There were 2262 cases (87.84%) with one stage of pneumoconiosis. The main types of work were rock driller (799 cases, 31.03%) , hauler (797 cases, 30.95%) , other mine workers (391 cases, 15.18%) . The economic type of enterprises was mainly state-owned enterprises (1156 cases, 44.89%) . The scale of enterprises mainly concentrated in large enterprises (1897 cases, 73.67%) .Conclusion:The new pneumoconiosis in Yantai City shows obvious concentration of disease and work types.It is necessary to strengthen the prevention and treatment of silicosis and the training of protection knowledge for rock drillers and transport workers.

Objective:To study the clinical efficacy of sequential glucocorticoids in the treatment of acute mercury poisoning complicated with interstitial pneumonia.Methods:Retrospective analysis of 37 patients with acute mercury poisoning complicated with interstitial pneumonia admitted from January 2009 to April 2019, including the sequential treatment group (15 cases) and the conventional treatment group (22 cases) , all patients were treated with sodium dimercaptopropane sulfonate, and given anti-inflammatory, liver-protecting and other drugs for symptomatic treatment. The conventional treatment group was given methylprednisolone 1mg/kg once a day for 5-7 days. The sequential treatment group was given 1 mg/kg of methylprednisolone once a day for 5-7 days, then gradually reduced to 20 mg, and the total course of treatment was 14-21 days. To observe the changes of clinical symptoms, signs, lung function including forced vital capacity (FVC) , forced expiratory volume in the first second (FEV 1) and ratio of forced expiratory volume in the first second to forced vital capacity (FEV 1/FVC) , and chest CT indexes before and after treatment in the two groups. Results:The clinical symptoms and signs of the two groups were significantly improved compared with those before treatment, and there was no significant difference between the apparent efficiency and the total effective rate of the two groups ( P>0.05) . The FVC, FEV 1, and FEV 1/FVC of the two groups were significantly higher than those before treatment. After treatment, the indexes of the sequential treatment group were significantly higher than that of the conventional treatment group, and the difference was statistically significant ( P<0.05) . The apparent efficiency (93.3%, 14/15) of CT lesions in the sequential treatment group was significantly higher than those of the conventional treatment group (59.1%, 13/22) , and the difference was statistically significant ( P< 0.05) . Conclusion:Sequential glucocorticoid treatment of acute mercury poisoning complicated with interstitial pneumonia could improve the effect of clinical signs and symptoms which is equal to conventional treatment, but it could better promote the recovery of lung function and the absorption of lung lesions.

Objective:To analyze the incidence characteristics of occupational chronic benzene poisoning under two diagnostic criteria.Methods:In March 2020, 126 patients who were divided into the old criteria group (74 cases) and the new criteria group (52 cases) were retrospectively analyzed. These patients were diagnosed with occupational chronic benzene poisoning, and were diagnosed in our hospital during the period of January 2009 to December 2019. The gender composition, age of onset, years of benzene exposure, industry distribution, work type, benzene concentration in working environment and diagnostic grade of the two groups of patients were analyzed and compared. The follow-up of 22 benzene poisoning observation subjects under the old criteria were retrospectively analyzed.Results:There were no statistically significant differences in gender composition, age of onset, years of benzene exposure, industry distribution and work type between the old criteria group and the new criteria group ( P>0.05) . In the old criteria group and the new criteria group, 41.9% (31/74) and 17.3% (9/52) of the patients' workplace benzene concentration exceeded the maximum allowable concentration, respectively. The composition of different benzene concentration in the workplace between the two groups showed statistically significant ( P<0.05) . In the old criteria group, the proportion of mild poisoning (79.7%, 59/74) was the majority, while in the new criteria group, the proportion of moderate and severe poisoning (51.9%, 27/52) were the majority, and there was statistically significance in the composition ratio of diagnostic grade between the two groups ( P<0.05) . Under the old criteria, after folow-up of 22 cases of benzene poisoning observation subjects, we observed that 8 cases (36.4%) progressed to the level of chronic benzene poisoning. Conclusion:The revision of diagnostic criteria for benzene poisoning may affect the composition of diagnosis classification. Based on the rights and interests of workers, formulating more complete diagnostic criteria and system policies will be more conducive to the development of occupational benzene poisoning prevention and control.

AIMTo explore the effects of tRNA on the growth of mammalian cells.

METHODSL929, NIH3T3, MCF-7 and PC12 cells were seeded in 96 well culture plate individually, and incubated at 37 degrees C in 5% CO2 for 4 h, the tRNAs from different species were added to the culture media individually. After certain time of incubation, the viability of the cells was evaluated by the MTT methods. Sub-confluent L929 cells were incubated with 200 microg/ml ytRNA for different times, then the cells were pooled and analyzed with flow cytometry assay.

RESULTStRNA specifically inhibited the growth of L929 cells in a dose-dependent manner. The sizes of tRNA-treated cells showed larger sizes and longer processes than those of untreated cells. Flow cytometric analysis further showed that most of tRNA-treated cells were arrested in S phase of the cell cycle.

CONCLUSIONThe cell growth inhibitory effects of tRNAs were caused mainly by their degraded fragments. The results suggested that tRNA or its degraded fragments might play important roles in regulation of cell proliferation.

Animals ; Cell Cycle Checkpoints ; physiology ; Cell Line ; Cell Proliferation ; Fibroblasts ; cytology ; Flow Cytometry ; Mice ; RNA, Transfer ; physiology