目的:探讨旋转细胞培养系统(RCCS)模拟失重环境对人SK-BR-3乳腺癌细胞生物学行为的影响.方法:体外培养人SK-BR-3乳腺癌细胞,将实验细胞随机分为模拟微重力组(SMG)和正常重力对照组(NG).应用RCCS模拟微重力环境.培养第3 d收取SMG组与NG组细胞进行检测:CCK-8法检测吸光度值,比较两组细胞增殖能力;流式细胞仪技术检测细胞周期和细胞凋亡变化;透射电镜观察细胞超微结构变化.结果:CCK-8检测结果显示,SMG组乳腺癌细胞的吸光值显著低于NG组(0.522±0.060 vs 1.327±0.090,P<0.001).流式细胞仪检测发现,SMG和NG组乳腺癌细胞的凋亡细胞率分别为(33.233±5.537)％和(5.500±1.572)％,差异有统计学意义(P=0.001);SMG组人SK-BR-3乳腺癌细胞G0/G1期、S期和G2/M期比例分别为(52.734±3.264)％、(36.864±2.918)％和(10.402±0.881)％,与NG组细胞G0/G1期、S期和G2/M期的对应比例(32.534±1.741)％、(53.924±3.215)％和(13.542±2.451)％相比,差异均有统计学意义(P<0.05).透射电镜结果显示,与NG组比较,SMG组人SK-BR-3乳腺癌细胞经RCCS模拟失重环境培养3 d后,线粒体水肿,次级溶酶体增多,细胞超微结构发生明显改变.结论:RCCS模拟失重环境下人SK-BR-3乳腺癌细胞凋亡增加,增殖受抑制,细胞周期和超微结构发生明显改变.

Microgravity is a component of the complex environment in space. Due to its adverse effects on the human body, it poses unknown obstacles to the implementation of space missions. In microgravity, the body often loses the point of force and it is difficult to control itself, which leads to various accidental collisions. As the largest organ of the human body, the skin is often damaged by traumatic injury because of its large contact area with the external environment. In this study, we summarized and discussed the latest research on the impact of weightlessness or simulated microgravity on the skin and the process of wound healing to further understand the changes and mechanisms of wound healing. A series of studies have investigated the effects of weightlessness or simulated microgravity on the human skin and the wound healing process. Under microgravity environment, the skin showed certain changes, such as thinning and altered blood supply; microgravity also affected various cellular functions and their associations with the extracellular matrix during wound healing. Various stages of wound healing and sophisticated interactions between the elements involved in wound healing become disordered in a microgravity environment. However, more studies are needed to further understand the impact and mechanisms of microgravity on the trauma repair process to provide theoretical guidance for wound healing. With the support and help of a lot of good researches and trails, accidental trauma will no longer be an obstacle to human exploration of space.

BackgroundWeightlessness is a component of the complex space environment. It exerts adverse effects on the human body, and may pose unknown challenges to the implementation of space missions. The regular function of the digestive system is an important checkpoint for astronauts to conduct missions. Simulated microgravity can recreate the changes experienced by the human body in a weightless environment in space to a certain extent, providing technical support for the exploration of its mechanism and a practical method for other scientific research.Methods and materialsIn the present study, we reviewed and discussed the latest research on the effects of weightlessness or simulated microgravity on the digestive system, as well as the current challenges and future expectations for progress in medical science and further space exploration.ResultsA series of studies have investigated the effects of weightlessness on the human digestive system. On one hand, weightlessness and the changing space environment may exert certain adverse effects on the human body. Studies based on cells or animals have demonstrated the complex effects on the human digestive system in response to weightlessness. On the other hand, a microgravity environment also facilitates the ideation of novel concepts for research in the domain of life science.ConclusionThe effects of weightlessness on the digestive system are considerably complicated. The emergence of methods that help simulate a weightless environment provides a more convenient alternative for assessing the impact and the mechanism underlying the effect of weightlessness on the human body. In addition, the simulated microgravity environment facilitates the ideation of novel concepts for application in regenerative medicine and other fields of life science.

Simulated microgravity can significantly affect various cell types and multiple systems of the human body, such as cardiovascular system, skeletal muscle system, and immune system, and is known to cause anemia and loss of electrolyte and fluids. Epidermal stem cells (EpSCs) were cultured in a rotary cell culture system (RCCS) bioreactor to simulate microgravity. The metabolites of EpSCs were identified by liquid chromatography-mass spectrometry (LC-MS). Compared with normal gravity (NG) group, a total of 57 different metabolites of EpSCs were identified ( P < 0.05, VIP > 1), including lipids and lipid-like molecules (51 molecules), amino acids (5 molecules), nucleosides, nucleotides, and analogues (1 molecule). According to the partial least squares discriminant analysis (PLS-DA) score plot, a VIP > 1 and P < 0.05 were obtained for the 57 different metabolites, of which 23 molecules were significantly downregulated and 34 were significantly upregulated in simulated microgravity (SMG) group. These results showed that SMG has a significant impact on different pathways, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis indicated that multiple pathways were involved, mainly the amino acid metabolism pathway, lipid metabolism pathway, membrane transport pathway, and cell growth and death pathways. Thus, the metabolic profile of EpSCs was changed under SMG. Exploring the metabolic profile of EpSCs would be helpful to further understand the growth characteristics of EpSCs under SMG, which will provide a new approach to explore the metabolomics mechanism of stress injury and repair trauma under SMG.

The understanding into the pathogenesis and treatment of gastric cancer has improved in recent years; however, a number of limitations have delayed the development of effective treatment. Cancer cells can undergo glycolysis and inhibit oxidative phosphorylation in the presence of oxygen (Warburg effect). Previous studies have demonstrated that a rotary cell culture system (RCCS) can induce glycolytic metabolism. In addition, the potential of regulating cancer cells by targeting their metabolites has led to the rapid development of metabolomics. In the present study, human HGC-27 gastric cancer cells were cultured in a RCCS bioreactor, simulating weightlessness. Subsequently, liquid chromatography-mass spectrometry was used to examine the effects of simulated microgravity (SMG) on the metabolism of HGC-27 cells. A total of 67 differentially regulated metabolites were identified, including upregulated and downregulated metabolites. Compared with the normal gravity group, phosphatidyl ethanolamine, phosphatidyl choline, arachidonic acid and sphinganine were significantly upregulated in SMG conditions, whereas sphingomyelin, phosphatidyl serine, phosphatidic acid, L-proline, creatine, pantothenic acid, oxidized glutathione, adenosine diphosphate and adenosine triphosphate were significantly downregulated. The Human Metabolome Database compound analysis revealed that lipids and lipid-like metabolites were primarily affected in an SMG environment in the present study. Overall, the findings of the present study may aid our understanding of gastric cancer by identifying the underlying mechanisms of metabolism of the disease under SMG.

With the rapid development of modern medical technology and the deterioration of living environments, cancer, the most important disease that threatens human health, has attracted increasing concerns. Although remarkable achievements have been made in tumor research during the past several decades, a series of problems such as tumor metastasis and drug resistance still need to be solved. Recently, relevant physiological changes during space exploration have attracted much attention. Thus, space exploration might provide some inspiration for cancer research. Using on ground different methods in order to simulate microgravity, structure and function of cancer cells undergo many unique changes, such as cell aggregation to form 3D spheroids, cell-cycle inhibition, and changes in migration ability and apoptosis. Although numerous better experiments have been conducted on this subject, the results are not consistent. The reason might be that different methods for simulation have been used, including clinostats, random positioning machine (RPM) and rotating wall vessel (RWV) and so on. Therefore, we review the relevant research and try to explain novel mechanisms underlying tumor cell changes under weightlessness.

目的 探讨旋转式细胞培养系统(RCCS)模拟微重力对人永生化角质形成细胞系(HaCaT)细胞代谢组学的影响.方法 应用RCCS建立模拟微重力细胞培养系统,体外培养HaCaT细胞,随机分为模拟微重力组(SMG组)和正常重力组(NG组),细胞培养1、2、3 d后收集样本,进行LC/MS代谢组学分析.结合正交偏最小二乘法(O-PLS-DA)和两样本独立t检验寻找两组细胞的差异代谢物,将差异代谢物输入KEGG数据库,进行代谢通路的构建与功能分析.结果 LC/MS代谢组学分析结果显示,与NG组比较,SMG组HaCaT细胞在RCCS模拟微重力环境中培养1 d后共有74种差异代谢物,其中16种表达上调,58种表达下调;2 d后共有89种差异代谢物,其中15种表达上调,74种表达下调;3 d后共有100种差异代谢物,其中23种表达上调,77种表达下调;以表达有统计学差异(VIP>1且P<0.05)的49种代谢物作为目标代谢标记物,其中鞘氨醇、谷氨酸、二十二碳五烯酸下调,脱水山梨糖醇等物质表达上调.KEGG分析显示,其涉及的代谢通路有氨基酸代谢、脂质代谢、细胞增殖和凋亡、物质转运、分解代谢、信号转导等.结论 RCCS模拟微重力环境可对角化细胞代谢产生明显影响,主要涉及鞘脂类、谷氨酸等代谢产物及相关信号通路.

Abstract Objective This study aimed to investigate changes in the ultrastructure, apoptosis, cycle progression, and migration ability of human MDA‐MB‐231 breast cancer cells under simulated microgravity conditions. Methods MDA‐MB‐231 breast cancer cells were cultured in a rotary cell culture system bioreactor to simulate microgravity for 7 days. The cells were randomly divided into a simulated microgravity (SMG) group and normal gravity control (NG) group. Changes in apoptosis, ultrastructure, cell cycle, and migration ability were evaluated. Results Transmission electron microscopy showed that cells in the SMG group had more secondary lysosomes than the NG groups. The flow cytometry assay showed that the proportion of apoptotic cells in the SMG group was significantly increased compared with the NG group; additionally, the median and interquartile spacing of the proportion of cells in the G0/G1 phase in the SMG group was lower than in the NG group, but the proportion of cells in the S phase was increased in the SMG group compared with the NG group. The transwell migration assay showed that cell migration in the SMG group was significantly reduced compared with the NG group. The expression of BCL‐2 and MMP9 in the SMG group was decreased compared with the NG group, whereas the expression of cyclin D3 in the SMG group was increased. Conclusion Simulated microgravity through rotary cell culture system had significant effects on human MDA‐MB‐231 breast cancer cells: the cell cycle and ultrastructure were impaired, apoptosis increased, migration ability decreased, and the expression of BCL‐2, cyclin D3, and MMP9 were affected.

Background: Gas-forming pyogenic liver abscess is a life-threatening disease with poor prognosis commonly caused by 2 bacteria, Klebsiella pneumoniae and Clostridium perfringens . Due to its low incidence and associated high mortality rate, it is important to study the biological characteristics of the disease. The aim of this study was to conduct a worldwide review of literature on gas-forming pyogenic liver abscess caused by K. pneumoniae and C. perfringens . Methods: We searched PubMed and Web of Science databases from January 2009 to March 2019, with published in English. All relevant articles were accessed in full text. The manual search included references of retrieved articles. Finally, 35 publications were selected for review. Results: The results showed that more cases of gas-forming pyogenic liver abscess in Asia were caused by K. pneumoniae than by C. perfringens (P=0.011). The prevalence of diabetes mellitus in patients with gas-forming pyogenic liver abscess caused by K. pneumoniae was higher than caused by C. perfringens (P=0.032). The survival rate of patients with gas-forming pyogenic liver abscess caused by K. pneumoniae who received surgical debridement or drainage was higher than caused by C. perfringens (P=0.002). Conclusions: The prevalence of diabetes mellitus was higher in patients with gas-forming pyogenic liver abscess caused by K. pneumoniae than in patients caused by C. perfringens .

目的 微重力对正常细胞和肿瘤细胞均有重要影响.微重力环境对人MDA-MB-231乳腺癌细胞影响的研究,仅有少数报道.本研究旨在探讨模拟微重力环境培养条件下人MDA-MB-231乳腺癌细胞超微结构、细胞凋亡、细胞周期及细胞迁移能力的变化.方法 体外培养人MDA-MB-231乳腺癌细胞,应用旋转细胞培养系统(rotating cell culture system,RCCS)建立模拟微重力细胞培养体系,将人MDA-MB-231乳腺癌细胞随机分为模拟微重力(simulated micro-gravity,SMG)组和正常重力对照(normal gravity,NG)组,经7 d培养后分别收集2组细胞,应用透射电镜观察细胞超微结构改变,流式细胞仪技术检测细胞凋亡和细胞周期,Transwell迁移实验检测细胞迁移能力改变,蛋白质印迹法检测细胞凋亡、周期和迁移相关蛋白的表达.结果 透射电镜结果显示,与NG组比较,SMG组人MDA-MB-231乳腺癌细胞经7 d培养后,细胞内次级溶酶体增多.流式细胞仪检测发现,SMG组人MDA-MB-231凋亡细胞比例为(31.100±5?803)％,相比于NG组的(7.067±1.930)％增加,差异有统计学意义,P=0.002.SMG组G0/G1期细胞比例的中位数(四分位间距)为46.250％(50.878),与NG组52.340％(57.710)相比减少,P=0.027;但S期细胞比例为(44.168±4?260)％,大于NG组的(37.094±3.880)％,差异有统计学意义,P=0.035.Transwell迁移实验结果显示,SMG组人MDA-MB-231乳腺癌细胞迁移数量(138.333±26.502)相比于NG组(592.667±60.929)减少,P<0.001.蛋白质印迹法检测结果表明,失重环境中MDA-MB-231乳腺癌细胞的Bcl-2(0.397±0.790)和MMP9(0.288±0.182)表达相比于NG组(Bcl-2为0.654±0.136,MMP9为0.611±0.029)减少,而SMG组Cyclin D3表达(1.577±0.868)相比于NG组(0.853±0.315)增加,差异均有统计学意义,均P<0.05.结论 在RCCS模拟微重力环境下,人MDA-MB-231乳腺癌细胞的细胞周期和超微结构发生改变,凋亡增加,迁移能力受到抑制,Bcl-2、Cyclin D3和MMP9的表达发生改变.

Objective To investigate the effects of simulated microgravity by RCCS on proliferation and cell cytoskeleton of human HaCaT keratinocyte. Methods The rotary cell culture system (RCCS) was used to simulate the microgravity environment, and human HaCaT keratinocytes were divided randomly(random number) into the simulated microgravity group (SMG) and normal gravity group (NG). HaCaT cells in the two groups were harvested respectively after 32, 36 and 42 h culture. The HaCaT cells proliferation and cycles were detected by flow cytometry, the concentration of hb-EGF in supernatant was detected by ELISA, and the cell cytoskeleton was observed after 42 hours' culture under laser confocal microscope with FITC-labeled technique. SPSS 23.0 statistical software was used for statistical analysis, and P <0.05 was considered statistically significant. Results The flow cytometry showed that the proportions of human HaCaT keratinocytes in G1 and G2/M phases were increased while the proportion of HaCaT cells in S stage was decreased significantly after 32, 36 and 42 h RCCSculture compared with those in the normal gravity group. The HaCaT cells in G1 stage were declined along with incubation time. ELISA results showed that the hb-EGF concentration in HaCaT supernatant under simulated microgravity culture for 24 and 36 h was lower than that in the normal control group (P<0.01). The laser confocal microscope revealed that the HaCaT fluorescence intensity was decreased,and there were disordered microfilaments, structural ambiguity, pseudopodia reduction and irregularshape among FITC-labeled HaCaT cells cultured 42 h in RSSC compared with the normal gravity group.Conclusions RCCS simulated microgravity environment could inhibit the cell cycle transformation and proliferation of human HaCaT keratinocyte, affect the keratinocyte-secreting function, and induce alterations of the cell cytoskeleton.

Human epidermal growth factor receptor-2 positive breast cancer (HER2+ BC) is characterized by a high rate of metastasis and drug resistance. The advent of targeted therapy drugs greatly improves the prognosis of HER2+ BC patients. However, drug resistance or severe side effects have limited the application of targeted therapy drugs. To achieve more effective treatment, considerable research has concentrated on strategies to overcome drug resistance. Abemaciclib (CDK4/6 inhibitor), a new antibody-drug conjugate (ADC), src homology 2 (SH2) containing tyrosine phosphatase-1 (SHP-1) and fatty acid synthase (FASN) have been demonstrated to improve drug resistance. In addition, using an effective vector to accurately deliver drugs to tumors has shown good application prospects. Many studies have also found that natural anti-cancer substances produced effective results during in vitro and in vivo anti-HER2+ BC research. This review aimed to summarize the current status of potential clinical drugs that may benefit HER2+ BC patients in the future.

The rotary cell culture system(RCCS)was used to simulate the microgravity environment, and FRTL-5 cells were divided into simulated microgravity group(SMG)and normal gravity group(NG). FRTL-5 cells were harvested after treatment for 6, 12, 24, and 36 h, the cell viability was measured by MTT assay, and the cells cycles were detected by flow cytometry. The ultrastructure of FRTL-5 cells was observed under laser confocal microscope with FITC-labeled technique. The MTT assay showed that the proliferation of FRTL-5 cells was significantly inhibited after RCCS treatment for 6, 12, 24, and 36h compared with NG(P<0.05), in which the most obvious effect was observed at 24h. The flow cytometry showed that the proportion of FRTL-5 cells at G1 stage in RCCS group was increased significantly after 6, 12, 24, and 36h compared with NG(P<0.05), while the proportion of FRTL-5 cells at S stage was decreased significantly(P<0.05)except that cultured with RCCS for 6 h. The proportion of FRTL-5 cells at G2/M stage was decreased in early phase(6-12 hours)of RCCS culture, with the lowest at 12h and transient increase at 24h of RCCS culture. The laser confocal microscope revealed that there were local microfilament depolymerization, tension fibers decrease, structure disorder, cellular pseudopodia reduction, and irregular shape among FITC-labeled FRTL-5 cells cultured with RCCS for 36h. (Chin J Endocrinol Metab, 2018, 34: 598-601) Key words: Simulated microgravity; Thyroid follicular epithelial cells; FRTL-5 cell line; Proliferation; Microfilament

Backgrounds: Neratinib is a potent EGFR/HER2 kinase inhibitor. Gastrointestinal complications (i.e. diarrhea, vomiting and nausea) are the most common adverse events. In this study, we aimed to investigate (1) the overall incidence and relative risk (RR) of diarrhea, vomiting and nausea and (2) whether combination neratinib therapy increased the incidence of gastrointestinal complications versus neratinib alone.Methods: Relevant studies were identified from the PubMed database, from abstracts presented at the American Society of Clinical Oncology annual conference and from the Web of Science database. Incidences, RRs, and 95% confidence intervals (CIs) were calculated.Results: The incidences of all-grade diarrhea, vomiting and nausea in the neratinib groups were 89% (95% CI = 77-95%), 31% (95% CI = 25-37%) and 44% (95% CI = 33-55%), respectively. The neratinib arms significantly increased the risk of diarrhea and vomiting in comparison with the control groups (diarrhea: all-grade, RR = 2.06, 95% CI = 1.38-3.08, P = 0.0004; grade 3/4, RR = 8.77, 95% CI = 2.91-26.40, P = 0.0001; vomiting: all-grade, RR = 2.02, 95% CI = 1.10-3.71, P = 0.02; grade 3/4, RR = 7.10, 95% CI = 3.33-15.15, P < 0.00001).Conclusions: Our meta-analysis demonstrates that the neratinib arms are associated with a significantly increased risk of diarrhea and vomiting.