In regenerating liver of mice, marked increase of the activity of phosphotyrosyl protein phosphatase (PTPP) in cytosol was observed. The PTPP activity varied with time and reached the highest level between 24 to 48 ho...In regenerating liver of mice, marked increase of the activity of phosphotyrosyl protein phosphatase (PTPP) in cytosol was observed. The PTPP activity varied with time and reached the highest level between 24 to 48 hours after partial hepatectomy. In H22a cells the PTPP activity found in every subcellular fraction was lower than that of the normal liver. The PTPP activity was mostly concentrated in lysosomes of normal liver, but mainly distributed in nucleus, cytosol and microsome of regenerating liver. In H22a cells PTPP activity seemed distribute evenly. Five similar major PTPP peaks (I-V) were obtained on DEAE cellulose chromatography of cytosols from all three of liver cells studied. However, two additional PTPP peaks, a and b, were also obtained from cytosol of liver.展开更多
文摘In regenerating liver of mice, marked increase of the activity of phosphotyrosyl protein phosphatase (PTPP) in cytosol was observed. The PTPP activity varied with time and reached the highest level between 24 to 48 hours after partial hepatectomy. In H22a cells the PTPP activity found in every subcellular fraction was lower than that of the normal liver. The PTPP activity was mostly concentrated in lysosomes of normal liver, but mainly distributed in nucleus, cytosol and microsome of regenerating liver. In H22a cells PTPP activity seemed distribute evenly. Five similar major PTPP peaks (I-V) were obtained on DEAE cellulose chromatography of cytosols from all three of liver cells studied. However, two additional PTPP peaks, a and b, were also obtained from cytosol of liver.
文摘目的:探讨紫草多糖是否通过诱导自噬而抑制H_(22)肝癌实体瘤细胞的增殖。方法:将40只KM小鼠随机分为模型组、环磷酰胺组(阳性药物,30 mg/kg,ip,每4 d给药1次)和紫草多糖低、高剂量组(100、300 mg/kg,ig,每天给药1次),每组10只。各组小鼠均腋下接种H_(22)细胞株复制H_(22)肝癌实体瘤模型,造模同时各给药组小鼠给予相应药物,模型组小鼠ig等体积生理盐水。末次给药后,记录并测定小鼠体质量、瘤质量系数和胸腺、脾脏指数;采用实时荧光定量聚合酶链式反应法测定小鼠瘤组织中自噬相关基因Atg5、Beclin1 m RNA表达水平;Western blot法测定瘤组织中自噬微管相关蛋白1轻链3A/B(LC3A/B)蛋白表达水平。结果:紫草多糖可显著降低H_(22)实体瘤小鼠的瘤质量系数,抑瘤率达34.7%;可显著上调瘤组织中自噬相关基因Atg5、Beclin1 m RNA的表达和LC3A/B蛋白的表达,较模型组差异均有统计学意义(P<0.05或P<0.01)。结论:紫草多糖通过促进肝癌细胞的自噬,从而抑制H_(22)肝癌实体瘤细胞的增殖、延缓肿瘤生长。