Sorafenib,rapamycin, and venetoclax attenuate doxorubicin-induced senescence and promote apoptosis in HCT116 cells

Emerging evidence has shown that the therapy-induced senescent growth arrest in cancer cells is of durable nature whereby a subset of cells can reinstate proliferative capacity. Promising new drugs named senolytics selectively target senescent cells and commit them into apoptosis. Accordingly, senolytics have been proposed as adjuvant cancer treatment to cull senescent tumor cells, and thus, screening for agents that exhibit senolytic properties is highly warranted. Our study aimed to investigate three agents, sorafenib, rapamycin, and venetoclax for their senolytic potential in doxorubicin-induced senescence in HCT116 cells. HCT116 cells were treated with one of the three agents, sorafenib (5 µM), rapamycin (100 nM), or venetoclax (10 µM), in the absence or presence of doxorubicin (1 µM). Senescence was evaluated using microscopy-based and flow cytometry-based Senescence-associated-β-galactosidase staining (SA-β-gal), while apoptosis was assessed using annexin V-FITC/PI, and Muse caspase-3/-7 activity assays. We screened for potential genes through which the three drugs exerted senolytic-like action using the Human Cancer Pathway Finder PCR array. The three agents reduced doxorubicin-induced senescent cell subpopulations and significantly enhanced the apoptotic effect of doxorubicin compared with those treated only with doxorubicin. The senescence genes IGFBP5 and BMI1 and the apoptosis genes CASP7 and CASP9 emerged as candidate genes through which the three drugs exhibited senolytic-like properties. These results suggest that the attenuation of doxorubicin-induced senescence might have shifted HCT116 cells to apoptosis by exposure to the tested pharmacological agents. Our work argues for the use of senolytics to reduce senescence-mediated resistance in tumor cells and to enhance chemotherapy efficacy.     

Efficacy of stem cell-based therapies for colistin-induced nephrotoxicity

The increase in infections with multidrug resistant bacteria has forced to return to the use of colistin, antibiotic with known nephrotoxicity. Mesenchymal stem cells (MSCs) are being extensively investigated for their potential in regenerative medicine. This study aimed to investigate the possible protective mechanisms of the MSCs against kidney injury induced by colistin. Forty adult female albino rats were randomly classified into 4 equal groups; the control group, the MSC-treated group (a single dose of 1 ×10⁶ /ml MSCs through the tail vein), the colistin-treated group (36 mg/kg/day colistin was given for 7 days), and the both colistin and MSC group (36 mg/kg/day colistin and 1 ×10⁶ /ml MSCs). Main outcome measures were histopathological alterations, kidney malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and immunohistological autophagy evaluation. MSC repressed the progression of colistin-induced kidney injury as evidenced by the improvement of histopathological alterations and the substantial increase MDA, and decrease SOD and CAT in serum levels. Moreover, MSC resulted in a profound reduction in oxidative stress as manifested by decreased MDA and increased SOD in serum. Notably, MSC suppressed colistin-induced autophagy; it reduced renal levels of Beclin-1, P62 and LC3A/B. Furthermore, MSC decreased renal levels of eNOS. Lastly, MSC efficiently decreased expression of the TUNEL positive cell number. MSC confers protection against colistin-induced kidney injury by alleviating oxidative stress, nitric oxide synthase besides modulating reducing autophagy and apoptosis.     

首发儿童精神分裂症患者脑源性神经营养因子水平及神经元凋亡研究

目的探讨首发儿童精神分裂症患者脑源性神经营养因子(BDNF)、β-微管蛋白III(Tuj-1)、胱天蛋白酶3(Caspase-3)的变化,为揭示儿童精神分裂症的病因和发病机制提供参考。方法以2015年8月-2018年3月在大理州第二人民医院就诊的符合《精神障碍诊断与统计手册(第4版)》(DSM-IV)诊断标准的儿童精神分裂症患者(n=35)为研究组,同期在大理州第二人民医院的体检儿童中随机选取健康儿童为对照组(n=30)。通过实时荧光定量逆转录-聚合酶链反应(RT-PCR)测定两组儿童血液中BDNF、Caspase-3和Tuj-1的mRNA表达水平。结果与对照组相比,研究组BDNF和Tuj-1 mRNA表达低(P0.05或0.01),Caspase-3 mRNA表达高(P0.01)。结论儿童精神分裂症患者的BDNF mRNA和Tuj-1 mRNA表达少,Caspase-3 mRNA表达多,BDNF mRNA、Tuj-1 mRNA和Caspase-3 mRNA可能与儿童精神分裂症相关。     

Molecular mechanisms and cellular events involved in the neuroprotective actions of estradiol. Analysis of sex differences

Estradiol, either from peripheral or central origin, activates multiple molecular neuroprotective and neuroreparative responses that, being mediated by estrogen receptors or by estrogen receptor independent mechanisms, are initiated at the membrane, the cytoplasm or the cell nucleus of neural cells. Estrogen-dependent signaling regulates a variety of cellular events, such as intracellular Ca²⁺ levels, mitochondrial respiratory capacity, ATP production, mitochondrial membrane potential, autophagy and apoptosis. In turn, these molecular and cellular actions of estradiol are integrated by neurons and non-neuronal cells to generate different tissue protective responses, decreasing blood-brain barrier permeability, oxidative stress, neuroinflammation and excitotoxicity and promoting synaptic plasticity, axonal growth, neurogenesis, remyelination and neuroregeneration. Recent findings indicate that the neuroprotective and neuroreparative actions of estradiol are different in males and females and further research is necessary to fully elucidate the causes for this sex difference.     

MicroRNA-301b-3p accelerates the growth of gastric cancer cells by targeting zinc finger and BTB domain containing 4

MicroRNAs (miRNAs) have been found to be aberrantly expressed and exert essential roles in the tumorigenesis and progression of gastric cancer (GC). miR-301b-3p has been recognized as a cancer-related miRNA in lung cancer, bladder cancer and hepatocellular carcinoma. However, the function of miR-301b-3p in GC progression and its underlying mechanism have not been studied yet. In this study, we found that miR-301b-3p expression was up-regulated in GC tissues compared to adjacent noncancerous tissues. Furthermore, the elevated levels of miR-301b-3p were detected in GC cell lines (SGC-7901, AGS, MKN-45 and MGC-803) as compared with GES-1 cells. Interestingly, GC tissues from patients with tumor size ≥ 5 cm and advanced tumor stages showed obvious higher levels of miR-301b-3p compared to matched controls. Functionally, miR-301b-3p knockdown prominently inhibited cell proliferation, and induced cell cycle arrest at G1 phase and apoptosis in MGC-803 cells. Meanwhile, ectopic expression of miR-301b-3p conversely regulated these biological behaviors of MKN-45 cells. Next, we found that miR-301b-3p knockdown increased, whereas miR-301b-3p overexpression reduced the expression of zinc finger and BTB domain containing 4 (ZBTB4) in GC cells. Accordingly, luciferase reporter assay identified ZBTB4 as a direct target of miR-301b-3p. ZBTB4 overexpression markedly restrained the growth of MGC-803 cells. More importantly, ZBTB4 silencing partially reversed miR-301b-3p knockdown-induced tumor suppressive effects on MGC-803 cells. In conclusion, we firstly revealed that miR-301-3p was highly expressed in GC and contributed to tumor progression via attenuating ZBTB4, which might provide a novel molecular-targeted strategy for GC treatment.     

The effect of ageing on the resolution of inflammation

Ageing is associated with the development of a low-level, systemic, chronic inflammation known as “inflammaging”. This chronic inflammatory state can contribute to diseases of ageing such as sarcopenia and frailty. The presence of inflammaging suggests a failure of the cell clearance mechanisms that ordinarily aid in the resolution of inflammation after pathogen infiltration or tissue injury. This review aims to explore what is known of how the processes involved in the resolution of inflammation might become defective with age.     

Tryptophanyl-tRNA Synthetase Sensitizes Hormone Receptor-Positive Breast Cancer to Docetaxel-Based Chemotherapy

PurposeA relatively low response to chemotherapy has been reported for hormone receptor (HR)-positive breast cancer. In this study, we investigated the role of tryptophanyl-transfer RNA synthetase (WARS) in the chemotherapeutic response of HR-positive breast cancer.MethodsPre-chemotherapeutic needle biopsy samples of 45 HR-positive breast cancer patients undergoing the same chemotherapeutic regimen were subjected to immunohistochemistry. To investigate the biological functions of WARS in HR-positive breast cancer, we conducted cell viability assay, flow cytometry analysis, caspase activity assay, Quantitative real-time polymerase chain reaction, and western blotting using WARS gene-modulated HR-positive breast cancer cells (T47D, ZR-75-1, and MCF7).ResultsWARS overexpression in HR-positive breast cancer patients showed a significant correlation with favorable chemotherapy response. Downregulation of WARS increased cell viability following docetaxel treatment in tumor cell lines. On the other hand, WARS overexpression sensitized the therapeutic response to docetaxel. Additionally, downregulation of WARS caused a decrease in the number of apoptotic cell populations by docetaxel. Poly (ADP-ribose) polymerase cleavage and caspase 3/7 activity were increased in docetaxel-treated tumor cells with WARS overexpression.ConclusionOur results suggest that WARS might be a potential predictor for chemotherapy response in patients with HR-positive breast cancer as well as a novel molecular target to improve chemosensitivity.     

Inhibition of fatty acid synthase (FASN) affects the proliferation and apoptosis of HepG2 hepatoma carcinoma cells via the β-catenin/C-myc signaling pathway

Introduction and objectivesResearch in the last few years has proven that inhibition of fatty acid synthase (FASN) suppresses the migration and invasion of hepatoma carcinoma cells. This study aims to explore the effect of fatty acid synthase knockdown on the apoptosis and proliferation of HepG2 cells.Materials and methodsThe human liver cancer cell line HepG2 was cultured and then transfected with FASN-specific siRNA and negative control RNAi. After 48 h, cells and protein lysates were used for western blotting, CCK-8 (cell counting kit-8) assays, flow cytometry and other tests. To assess cell apoptosis, Bax, Bcl-2 and caspase-3 were detected; to assess proliferation, CDK4 (cyclin-dependent kinases 4) and P21 were detected; and to determine the signaling pathway involved, β-catenin and C-myc were also detected.ResultsInhibition of FASN in HepG2 cells can decrease proliferation and promote apoptosis. Flow cytometry and CCK-8 assays demonstrated that the apoptosis rate of FASN-specific siRNA-transfected cells was significantly increased compared to that of the control cells (p < 0.01). In addition, the cell cycle analysis revealed that FASN-specific siRNA-transfected cells induced G1 phase arrest (p < 0.05), but an increasing trend in G2 (p < 0.05).Compared with expression in negative RNAi-transfected cells, the expression of Bcl-2 and CDK-4 was reduced and the expression of Bax, caspase-3 and P21 was increased in FASN-specific siRNA-transfected cells (p < 0.05). Regarding the signaling pathway, the expression of β-catenin and C-myc was significantly reduced when compared to that in negative control cells (p < 0.05).ConclusionsInhibition of FASN suppressed the cell survival of HepG2 cells by inhibiting the β-catenin/C-myc pathway. This result suggests the potential treatment value of FASN for hepatoma carcinoma (HCC).     

电针干预佐剂性关节炎大鼠踝关节滑膜细胞凋亡的MMP-3、MMP-9分子调节机制

目的观察电针干预对佐剂性关节炎大鼠踝关节滑膜细胞凋亡和相关蛋白基质金属蛋白酶-3(MMP-3)、基质金属蛋白酶-9(MMP-9)表达的影响。方法32只雄性SD大鼠被随机分为生理盐水组、模型组、电针干预组和假电针干预组,每组8只。生理盐水组大鼠在双侧足垫部注射模拟造模,其余大鼠用弗氏完全佐剂在双侧足垫部注射造模。电针干预组大鼠予以电针干预。假电针干预组予以假电针刺激处理。HE染色观察模型大鼠踝关节炎症进展情况,Tunnel法检测模型大鼠踝关节滑膜细胞凋亡情况,RT-PCR检测踝关节滑膜的MMP-3、MMP-9的mRNA表达,Western blot检测踝关节滑膜的MMP-3、MMP-9的蛋白表达。结果HE染色显示,电针干预组大鼠的关节炎症显著轻于模型组。Tunnel法检测,电针干预可以促进关节炎大鼠的滑膜细胞凋亡。RT-PCR和Western blot检测结果显示,电针干预可以显著降低关节炎大鼠踝关节滑膜组织中的MMP-3、MMP-9 mRNA和蛋白表达水平(P<0.05)。结论电针干预可以显著减轻佐剂性关节炎大鼠的关节炎症和增殖的滑膜细胞数量,其分子机制可能和电针降低局部的MMP-3、MMP-9蛋白的表达有关。