Gadd45a基因对小鼠造血干细胞功能的影响

目的 Gadd45a基因对小鼠造血干细胞功能的影响。方法流式细胞仪分选小鼠骨髓造血干细胞、体外单克隆培养,竞争性骨髓移植,放射线照射观察生存曲线。结果 Gadd45a基因缺失的小鼠造血干细胞克隆形成能力增强,短期造血重建能力无差异,8.5Gy放射线照射后生存情况无差异。结论 Gadd45a基因对小鼠造血干细胞功能起重要作用。     

Mathematical modelling of the Warburg effect in tumour cords

The model proposed here links together two approaches to describe tumours: a continuous medium to describe the movement and the mechanical properties of the tissue, and a population dynamics approach to represent internal genetic inhomogeneity and instability of the tumour. In this way one can build models which cover several stages of tumour progression. In this paper we focus on describing transition from aerobic to purely glycolytic metabolism (the Warburg effect) in tumour cords. From the mathematical point of view this model leads to a free boundary problem where domains in contact are characterized by different sets of equations. Accurate stitching of the solution was possible with a modified ghost fluid method. Growth and death of the cells and uptake of the nutrients are related through ATP production and energy costs of the cellular processes. In the framework of the bi-population model this allowed to keep the number of model parameters relatively small.     

A positive feedback loop between miR‐181b and STAT3 that affects Warburg effect in colon cancer via regulating PIAS3 expression

This study aimed to investigate the relationship between the expression of microRNA (miR)‐181b, protein inhibitor of activated STAT3 (PIAS3) and STAT3, and to examine the function of the miR‐181b/PIAS3/STAT3 axis on the Warburg effect and xenograft tumour growth of colon cancer. Moreover, a positive feedback loop between miR‐181b and STAT3 that regulated the Warburg effect in colon cancer was explored. A luciferase reporter assay was used to identify whether PIAS3 was a direct target of miR‐181b. The gain‐of‐function and loss‐of‐function experiments were performed on HCT 116 cells to investigate the effect of miR‐181b/PIAS3/STAT3 on the Warburg effect and xenograft tumour growth of colon cancer, as determined by commercial kits and xenograft experiments. The relationship between the expression of miR‐181b, PIAS3 and STAT3 in HCT 116 and HT‐29 cells was determined using RT‐qPCR and Western blot. We found miR‐181b was a direct regulator of PIAS3. miR‐181b promoted the Warburg effect and the growth of colon cancer xenografts; however, these effects could be reversed by PIAS3. miR‐181b expression interacted with STAT3 phosphorylation in a positive feedback loop in colon cancer cells via regulating PIAS3 expression. In conclusion, this study for the first time demonstrated that miR‐181b contributed to the Warburg effect and xenograft tumour growth of colon cancer by targeting PIAS3. Moreover, a positive feedback loop between miR‐181b and STAT3 that regulated the Warburg effect in colon cancer was also demonstrated. This study suggested miR‐181b/PIAS3/STAT3 axis as a novel target for colon cancer treatment.     

血清LncRNA XIST与miR-33a在膀胱癌中的表达及临床意义

目的:探究血清长链非编码RNA X染色体失活特异转录本(Lnc RNA XIST)与微小RNA-33a(mi R-33a)在膀胱癌中的表达及临床意义。方法:选择2017年4月至2019年8月青岛大学附属医院诊治的95例膀胱癌患者作为膀胱癌组,选择同期体检的95例健康者作为健康组。采用荧光定量PCR检测两组的血清LncRNA XIST与mi R-33a表达水平,分析患者的临床病理参数与血清LncRNA XIST、mi R-33a表达水平的关系,采用受试者工作特征曲线(ROC)分析血清LncRNA XIST与mi R-33a对膀胱癌的预测价值。结果:与健康组相比,膀胱癌组的血清LncRNA XIST表达水平明显升高(P0.05),而血清mi R-33a表达水平明显下降(P0.05)。血清LncRNA XIST与mi R-33a表达均与膀胱癌患者的TNM分期和淋巴结转移情况相关(P0.05)。血清LncRNA XIST联合mi R-33a(AUC=0.830,敏感性=90.47%,特异性=89.85%)预测膀胱癌的临床价值明显高于血清LncRNA XIST(AUC=0.716,敏感性=81.36%,特异性=80.74%)及血清mi R-33a(AUC=0.736,敏感性=82.19%,特异性=81.09%)单独检测。结论:血清LncRNA XIST表达异常升高、血清mi R-33a表达降低与膀胱癌发生密切相关,联合检测有助于预测膀胱癌发生的风险,从而为临床制定针对性干预和治疗方案提供参考。     

AKT-mediated phosphorylation of ATG4B impairs mitochondrial activity and enhances the Warburg effect in hepatocellular carcinoma cells

Phosphorylation is a major type of post-translational modification, which can influence the cellular physiological function. ATG4B, a key macroautophagy/autophagy-related protein, has a potential effect on the survival of tumor cells. However, the role of ATG4B phosphorylation in cancers is still unknown. In this study, we identified a novel phosphorylation site at Ser34 of ATG4B induced by AKT in HCC cells. The phosphorylation of ATG4B at Ser34 had little effect on autophagic flux, but promoted the Warburg effect including the increase of L-lactate production and glucose consumption, and the decrease of oxygen consumption in HCC cells. The Ser34 phosphorylation of ATG4B also contributed to the impairment of mitochondrial activity including the inhibition of F₁Fo-ATP synthase activity and the elevation of mitochondrial ROS in HCC cells. Moreover, the phosphorylation of ATG4B at Ser34 enhanced its mitochondrial location and the subsequent colocalization with F₁Fo-ATP synthase in HCC cells. Furthermore, recombinant human ATG4B protein suppressed the activity of F₁Fo-ATP synthase in MgATP submitochondrial particles from patient-derived HCC tissues in vitro. In brief, our results demonstrate for the first time that the phosphorylation of ATG4B at Ser34 participates in the metabolic reprogramming of HCC cells via repressing mitochondrial function, which possibly results from the Ser34 phosphorylation-induced mitochondrial enrichment of ATG4B and the subsequent inhibition of F₁Fo-ATP synthase activity. Our findings reveal a noncanonical working pattern of ATG4B under pathological conditions, which may provide a scientific basis for developing novel strategies for HCC treatment by targeting ATG4B and its Ser34 phosphorylation.