庆大霉素诱导LLC-PK1细胞凋亡与p27Kip1表达关系的研究

目的　观察庆大霉素对体外培养的肾小管上皮细胞凋亡的诱导作用 ;研究细胞周期调节蛋白 p2 7Kip1蛋白和mRNA表达在凋亡过程中的变化 ;并探讨细胞凋亡与p2 7Kip1之间的关系。方法　对体外培养的猪肾近端小管上皮细胞株 (LLC PK1细胞 )予以不同浓度的庆大霉素溶液分别作用 2 4～ 96h ,以MTT法测定庆大霉素对LLC PK1细胞增殖的抑制率 ,抽提细胞DNA进行琼脂糖凝胶电泳观察细胞凋亡条带 ,流式细胞术测定细胞凋亡率和细胞增殖动力学 ,WesternBlot法检测细胞内p2 7Kip1的蛋白表达 ,RT PCR法检测细胞p2 7Kip1mRNA表达的变化。结果　庆大霉素对LLC PK1细胞增殖有抑制作用 ,具诱导LLC PK1细胞凋亡的作用 ,凋亡率呈药物浓度和作用时间依赖性 ;庆大霉素致细胞周期停滞于G1期。p2 7Kip1蛋白在细胞内的表达随着干预的庆大霉素浓度增加而逐渐上调 ,蛋白水平与凋亡率之间呈正相关 ,其mRNA表达趋势与其蛋白表达一致。结论　庆大霉素诱导的LLC PK1细胞凋亡与细胞周期蛋白p2 7Kip1表达密切相关。     

Ergosta-7,22-diene-2β,3α,9α-triol from the fruit bodies of Ganoderma lucidum induces apoptosis in human myelocytic HL-60 cells

Ganoderma lucidum is known as a medicinal mushroom used in traditional medicine. In our study, the cytotoxic activities of 17 compounds (1-17) isolated from the fruiting bodies of G. lucidum were investigated. Among them, ergosta-7,22-diene-2β,3α,9α-triol (EGDT) induced apoptosis in HL-60 human premyelocytic leukemia cells. EGDT activated the apoptotic process, including DNA fragmentation and caspase-3 activity. In immunoblotting analysis, treatment with EGDT resulted in the cleavage of procaspase-3 and poly(ADP-ribose) polymerase (PARP) into active forms. In the in vivo study, the administration (i.p.) of EGDT to Lewis lung carcinoma (LLC)-inoculated mice evidenced a significant inhibition of tumor growth. These results indicate that EGDT was one of the apoptotic constituents of G. lucidum, and might be an antitumor agent.     

小剂量X射线全身照射提高小鼠抗瘤能力的整体和离体研究

本文作者利用肿瘤血道转移和自发转移模型，从整体和离体两方面观察７５ｍＧｙＸ射线全身照射对小鼠抗瘤能力的影响。结果发现：①与假照组相比，照射组小鼠Ｂ１６黑色素瘤血道肺转移结节数明显降低（Ｐ＜０．０１）；过继转移至同系小鼠体内的脾细胞，可明显抑制Ｌｅｗｉｓ肺癌（ＬＬＣ）的局部生长和自发肺转移（Ｐ＜０．０５～０．０１）。②与假照组相比，体外检测照射组小鼠脾细胞对ＣｏｎＡＩＬ－２反应性增强（Ｐ＜０．０１），ＮＫ活性明显提高（Ｐ＜０．０１）；体内检测其巨噬细胞功能也显著增强（Ｐ＜０．０１），１２５ＩＵｄＲ标记黑色素瘤细胞在肺内的存留率显著降低（Ｐ＜０．０１）。上述结果提示，小剂量辐射可明显提高小鼠的抗瘤能力；机体免疫功能的增强可能是其抗肿瘤效应的主要机理之一。     

MAPK regulation and caspase activation are required in DMNQ S-52 induced apoptosis in Lewis lung carcinoma cells

6-(1-Hydroxyimino-4-methylpentyl)5,8-dimethyoxy 1,4-naphthoquinone S-52 (DMNQ S-52) was reported to have cytotoxic activity against L1210 leukemia cells. In the present study, we investigated the apoptotic mechanism of DMNQ S-52 in vitro and in vivo in murine solid cancer cells. DMNQ S-52 exerted cytotoxicity against Lewis lung carcinoma (LLC) cells (IC50=12.3 microM). DMNQ S-52 increased Annexin V positive cell population in a concentration-dependent manner. DMNQ S-52 also induced apoptosis through caspase-mediated pathway, including activation of caspase-3, cleavage of Poly(ADP-ribose) polymerase (PARP) and decreased expression of Bcl-2 in LLC cells in a time and concentration-dependent fashion. DMNQ S-52 activated the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 as well as abrogated the expression of extracellular signal-regulated kinase (ERK) in a time-dependent manner at 10 microM. Similarly, cell proliferation inhibition by DMNQ S-52 was masked by caspase inhibitor Z-Asp-Glu-Val-Asp-fluoromethylketone (Z-VAD-FMK), JNK inhibitor SP600125 and p38 inhibitor SB203580, but not by MEK inhibitor U0126. Furthermore, i.p. administration of DMNQ S-52 at 5 mg/kg resulted in a potent inhibition of the growth of LLC cells implanted on the right flank of C57BL/6 mice compared to untreated control. Immunohistochemical analysis revealed the decreased tumor cell proliferation and increased tumor cell apoptosis in DMNQ S-52 treated tumor sections using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) and proliferation cell nuclear antigen (PCNA). Taken together, these findings demonstrate that DMNQ S-52 may exhibit anti-tumor activity by inducing apoptosis via caspases and mitogen activated protein (MAP) kinase-dependent pathways.     

What's Old Is New Again: Laboratory Oversight of Point of Care Testing—Guidelines,Challenges, and Practical Strategies

Laboratory medicine has evolved significantly over the past 45 years. Collaboration with other health care workers has always been important; today, it is even more important when developing new services, such as point-of-care testing (POCT) performed by non-laboratory staff with governance and oversight by laboratory personnel. POCT implies near-patient testing with the objective of generating rapid results for immediate management and treatment decisions. Although POCT dates back many years, what is old is now new again. We have seen a significant increase in POCT in the past 20-plus years, with predictions for even more testing with the advent of new technology. This article provides an overview of common challenges and practical examples for addressing POCT in daily clinical practice.