Members of the RAS proto-oncogene superfamily are indispensable molecular switches that play critical roles in cell proliferation, differentiation, and cell survival. Recent studies have attempted to prevent the inter...Members of the RAS proto-oncogene superfamily are indispensable molecular switches that play critical roles in cell proliferation, differentiation, and cell survival. Recent studies have attempted to prevent the interaction of RAS/GTP with RAS guanine nucleotide exchange factors(GEFs), impair RASeffector interactions, and suppress RAS localization to prevent oncogenic signalling. The present study aimed to investigate the effect of the natural triterpenoic acid inhibitor glycyrrhetinic acid, which is isolated from the roots of Glycyrrhiza plant species, on RAS stability. We found that glycyrrhetinic acid may bind to the P-loop of RAS and alter its stability. Based on our biochemical tests and structural analysis results, glycyrrhetinic acid induced a conformational change in RAS. Meanwhile, glycyrrhetinic acid abolishes the function of RAS by interfering with the effector protein RAF kinase activation and RAS/MAPK signalling.展开更多
B—RAF是促分裂素原活化蛋白激酶（mitogen—activated protein kinase，MAPK）信号转导通路中一个重要的丝氨酸一苏氨酸蛋白激酶。它的激活突变能够促进细胞的转化与增殖，因此与肿瘤发生密切相关。B-RAF的主要突变形式B—RAF V600E发...B—RAF是促分裂素原活化蛋白激酶（mitogen—activated protein kinase，MAPK）信号转导通路中一个重要的丝氨酸一苏氨酸蛋白激酶。它的激活突变能够促进细胞的转化与增殖，因此与肿瘤发生密切相关。B-RAF的主要突变形式B—RAF V600E发生于约8％的实体肿瘤中，其中占黑色素瘤的50％～80％、乳突型甲状腺癌的30％～70％、结肠癌的5％～15％以及非小细胞肺癌的2％～4％。目前，基于B-RAF的特异性抑制剂在临床上治疗B—RAF V600E的黑色素瘤取得了良好成效，但这些一代B-RAF抑制剂依然存在许多问题，包括不良反应大、迅速耐药以及适应症有限等。本文综述了B-RAF突变作为肿瘤治疗靶点的依据、3种FDA批准的针对B-RAF V600E突变的靶向抑制剂的临床疗效及其肿瘤耐药机制以及第2代B—RAF抑制剂的研发前景。展开更多
Objective： To observe the effects of p38 mitogen activated protein kinase （MAPK） inhibitor SB203580 by intrathecal injection on the pain behavior and the spinal proinflammatory cytokines in a rat model of bone canc...Objective： To observe the effects of p38 mitogen activated protein kinase （MAPK） inhibitor SB203580 by intrathecal injection on the pain behavior and the spinal proinflammatory cytokines in a rat model of bone cancer pain induced by breast cancer cells. Methods： Eleven rats were used to establish the models of bone cancer pain, six rats were treated by intrathecal SB203580 injection, and the other 5 were as the controls. The paw withdrawal latency （PWL）, histology and the spinal levels of IL-1β and TNF-α were detected. Results： All the 11 rats presented evident bone destruction and thermal hyperalgesia after intra-tibial injection of breast cancer cells. No effect of SB203580 on the bone destruction was observed. However, following intrathecal injection of SB203580, the left PWLs （12.12± 1.26 s at 16 days and 12.99 ± 1.65 s at 19 days） were significant higher than that of controls （9.05 ± 1.08 s at 16 days and 8.55 ± 1.60 s at 19 days）, P 〈 0.05. Meanwhile, inkathecal injection of SB203580 evidently reduced the levels of spinal IL-1β and TNF-α. Conclusion： Intrathecal injection of SB203580 in a rat model of bone cancer pain cannot prevent the tibial destruction but significantly depress the thermalgia sensitivity, which might result from inhibiting inkacellular p38 MAPK signaling transduction, and thereby reducing the release of the proinflammatory cytokines.展开更多
Arsenic is a highly toxic and carcinogenic metalloid widely dispersed in the environment, contaminating water and soil and accumulating in crops. Paradoxically, arsenic is also part of modern therapy and employed in t...Arsenic is a highly toxic and carcinogenic metalloid widely dispersed in the environment, contaminating water and soil and accumulating in crops. Paradoxically, arsenic is also part of modern therapy and employed in treating numerous ailments and diseases. Hence, inventing strategies to tune cellular arsenic uptake based on purpose is striking. Here, we describe an approach in which the arsenite uptake can be increased using a MAPK inhibitor. Employing microfluidic flow chambers in combination with optical tweezers and fluorescent microscopy, we elevated the influx of arsenite into the yeast Saccharomyces cerevisiae cells following short-term treatment with a Hog1 kinase inhibitor. The increase in arsenite uptake was followed on arsenite triggered redistribution of a reporter protein, Hsp104-GFP, which was imaged over time. The effect was even more pronounced when the yeast mother and daughter cells were analyzed disjointedly, an opportunity provided owing to single-cell analysis. Our data firstly provide a strategy to increase arsenite uptake and secondly show that arsenite triggered aggregates, previously shown to be sites of damaged proteins, are distributed asymmetrically and less accumulated in daughter cells. Inventing approaches to tune arsenite uptake has a great value for its use in environmental as well as medical applications.展开更多
基金supported by grants from National Natural Science Foundation of China (Grant Nos. 81430095, 81673616, and 81473403)International Cooperation and Exchange of the National Natural Science Foundation of China (Grant No. 81761168039)
文摘Members of the RAS proto-oncogene superfamily are indispensable molecular switches that play critical roles in cell proliferation, differentiation, and cell survival. Recent studies have attempted to prevent the interaction of RAS/GTP with RAS guanine nucleotide exchange factors(GEFs), impair RASeffector interactions, and suppress RAS localization to prevent oncogenic signalling. The present study aimed to investigate the effect of the natural triterpenoic acid inhibitor glycyrrhetinic acid, which is isolated from the roots of Glycyrrhiza plant species, on RAS stability. We found that glycyrrhetinic acid may bind to the P-loop of RAS and alter its stability. Based on our biochemical tests and structural analysis results, glycyrrhetinic acid induced a conformational change in RAS. Meanwhile, glycyrrhetinic acid abolishes the function of RAS by interfering with the effector protein RAF kinase activation and RAS/MAPK signalling.
基金a grant from the National Nature Sciences Foundation of China (No. 30672426).
文摘Objective： To observe the effects of p38 mitogen activated protein kinase （MAPK） inhibitor SB203580 by intrathecal injection on the pain behavior and the spinal proinflammatory cytokines in a rat model of bone cancer pain induced by breast cancer cells. Methods： Eleven rats were used to establish the models of bone cancer pain, six rats were treated by intrathecal SB203580 injection, and the other 5 were as the controls. The paw withdrawal latency （PWL）, histology and the spinal levels of IL-1β and TNF-α were detected. Results： All the 11 rats presented evident bone destruction and thermal hyperalgesia after intra-tibial injection of breast cancer cells. No effect of SB203580 on the bone destruction was observed. However, following intrathecal injection of SB203580, the left PWLs （12.12± 1.26 s at 16 days and 12.99 ± 1.65 s at 19 days） were significant higher than that of controls （9.05 ± 1.08 s at 16 days and 8.55 ± 1.60 s at 19 days）, P 〈 0.05. Meanwhile, inkathecal injection of SB203580 evidently reduced the levels of spinal IL-1β and TNF-α. Conclusion： Intrathecal injection of SB203580 in a rat model of bone cancer pain cannot prevent the tibial destruction but significantly depress the thermalgia sensitivity, which might result from inhibiting inkacellular p38 MAPK signaling transduction, and thereby reducing the release of the proinflammatory cytokines.
文摘Arsenic is a highly toxic and carcinogenic metalloid widely dispersed in the environment, contaminating water and soil and accumulating in crops. Paradoxically, arsenic is also part of modern therapy and employed in treating numerous ailments and diseases. Hence, inventing strategies to tune cellular arsenic uptake based on purpose is striking. Here, we describe an approach in which the arsenite uptake can be increased using a MAPK inhibitor. Employing microfluidic flow chambers in combination with optical tweezers and fluorescent microscopy, we elevated the influx of arsenite into the yeast Saccharomyces cerevisiae cells following short-term treatment with a Hog1 kinase inhibitor. The increase in arsenite uptake was followed on arsenite triggered redistribution of a reporter protein, Hsp104-GFP, which was imaged over time. The effect was even more pronounced when the yeast mother and daughter cells were analyzed disjointedly, an opportunity provided owing to single-cell analysis. Our data firstly provide a strategy to increase arsenite uptake and secondly show that arsenite triggered aggregates, previously shown to be sites of damaged proteins, are distributed asymmetrically and less accumulated in daughter cells. Inventing approaches to tune arsenite uptake has a great value for its use in environmental as well as medical applications.
