Detection of proteins that recognize platinum-modified DNA using gel mobility shift assay

Using a gel mobility shift assay, we have identified proteins, in the nuclear extracts of a human lung cancer cell line, that recognize cis-diamminedichloroplatinum(II) (cis-DDP, CDDP)-modified DNA. A 158-base-pair double-stranded DNA fragment, derived from pBR322 plasmid DNA, was modified by either CDDP, tetrachloro(dl-trans)-1,2-diaminocyclohexaneplatinum(IV) (tetraplatin) or trans-DDP (the stereoisomer of CDDP and clinically ineffective). These platinum drug-modified probes were incubated with nuclear extracts and analyzed by gel mobility shift assay. Proteins in the extracts selectively recognized the clinically active platinum-modified DNA fragment. No binding to the trans-DDP-modified DNA fragment was observed. These proteins may play a role in the cytotoxicity or in a DNA repair process.     

高迁移率族蛋白B1与肿瘤的相关性

高迁移率族蛋白B1(HMGB1)是一种核内非组蛋白染色质结合蛋白,通过与其受体相互作用产生广泛生物效应,可参与转录调节,诱导炎症反应等,并与风湿免疫性疾病密切相关.近年研究发现,HMGB1在多种恶性肿瘤中呈高表达,其表达水平与肿瘤分化、侵袭、转移呈正相关.HMGB1有望成为一种新的抗肿瘤治疗靶分子.     

高迁移率族蛋白B1与胰腺癌的关系

高迁移率族蛋白B1(HMGB1)是细胞内的非组蛋白染色体结合蛋白,在维持核小体稳定和DNA重组、复制、修复及基因转录中发挥着重要作用.而细胞外HMGB1可作为一种晚期炎症介质,在炎症的晚期阶段启动着炎症反应.最近研究发现,HMGB1作为一种非组蛋白染色体蛋白质,与胰腺癌的生长、浸润、转移密切相关,能促使细胞外基质降解,促进胰腺癌浸润、转移.     

高迁移率族蛋白B1与肿瘤侵袭性的研究进展

既往高迁移率族蛋白B1被认为是典型的非组DNA结合蛋白,在细胞核内参与DNA的稳定及基因转录的功能。近年来研究表明,高迁移率族蛋白B1在多种肿瘤内过度表达并且与肿瘤的浸润性生长密切相关。     

High mobility group 1 and 2 proteins bind preferentially to DNA that contains bulky adducts induced by benzo[a]pyrene diol epoxide and N-acetoxy-acetylaminofluorene

High mobility group (HMG) proteins 1 and 2 are abundant non-histone chromosomal proteins that bind preferentially DNA that is bent or underwound. Previous studies have shown that these proteins preferentially bind to DNA damaged by the crosslinking agents cis-diammine-dichloro-platinum(II), chromium(III) and UV-C radiation. Here we have studied the binding of HMG-1/2 proteins to a duplex oligonucleotide damaged by benzo(a)pyrene diol epoxide or N-acetoxy-acetylaminofluorene using an electrophoretic mobility shift assay. Both chemicals induce monoadducts that are known to distort DNA structure. The affinities of HMG-1/2 for DNA damaged by benzo[a]pyrene diol epoxide or N-acetoxy-acetylaminofluorene were similar to that for UV-irradiated DNA, which were an order of magnitude higher than for undamaged DNA. In contrast, DNA modified by dimethyl sulfate was not preferentially recognised by HMG-1/2.     

高迁移率族蛋白B1及其在宫颈癌中的作用

胞外的高迁移率族蛋白B1(HMGB1)与晚期糖基化终末产物受体、Toll样受体、趋化因子CXCL12等相关受体及肿瘤信号调控通路作用引起持续的炎症反应,并最终促进肿瘤发生.在宫颈癌患者中,HMGB1的表达水平随宫颈癌变级别的升高而增加,HMGB1通过多种途径参与宫颈癌的发生发展、浸润和转移过程.应用RNA干扰技术可以抑制HMGB1基因表达,从而影响宫颈癌细胞的增殖、侵袭和分化,这为抗肿瘤药物的研发提供了新的思路.     

High mobility group A1 expression correlates with the histological grade of human glial tumors

Glioblastoma is one of the most aggressive tumors in mankind with 50% of patients dying within the 1st year of diagnosis, and being refractory to conventional therapies. The aim of our work has been to analyse the expression of the HMGA1 proteins in human astrocytomas and glioblastomas in order to verify whether the detection of these proteins might be of some help in the diagnosis of these neoplasias. Here we report the analysis of 27 cases, including 12 astrocytomas and 15 glioblastomas, for HMGA1 expression. All the neoplastic samples showed positive staining even though the number of positive cells and the staining intensity was higher in glioblastomas compared to astrocytomas. Conversely, HMGA1 proteins were not detected in normal brain. Accordingly, expression of the hmga1 gene, analysed by RT-PCR, was higher in glioblastomas than in astrocytomas.     

Role of the high mobility group A proteins in human lipomas

The HMGA family is comprised of four proteins: HMGA1a, HMGA1b, HMGA1c and HMGA2. The first three proteins are products of the same gene, HMGA1, generated through an alternative splicing mechanism. The HMGA proteins are involved in the regulation of chromatin structure and HMGA DNA-binding sites have been identified in functional regions of many gene promoters. Rearrangements of the HMGA2 gene have been frequently detected in human benign tumors of mesenchymal origin including lipomas. 12q13-15 chromosomal translocations involving the HMGA2 gene locus, account for these rearrangements. The HMGA proteins have three AT-hook domains and an acidic C-terminal tail. The HMGA2 modifications consist in the loss of the C-terminal tail and fusion with ectopic sequences. A pivotal role of the HMGA2 rearrangements in the process of lipomagenesis is suggested by experiments showing that transgenic mice carrying a truncated HMGA2 gene showed a giant phenotype together with abdominal/pelvic lipomatosis. As HMGA2 null mice showed a great reduction in fat tissue, a positive role of the HMGA2 gene in adipocytic cell proliferation is proposed. More recently, similar alterations of the HMGA1 gene have been described. As the block of the HMGA1 protein synthesis induces an increase in growth rate of the pre-adipocytic cell line 3T3-L1, we suggest a negative role of the HMGA1 proteins in adipocytic cell growth and, therefore, we propose that adipocytic cell growth derives from the balance of the HMGA1 and HMGA2 protein functions.     

高迁移率族蛋白A2与肿瘤

高迁移率族蛋白A2是一种非组蛋白的染色质相关蛋白,通过与染色质结合后改变其构象,从而激活或抑制转录因子的活性来调节某些基因的转录,进而通过不同的机制导致肿瘤的形成。本文对高迁移率蛋白A2在肿瘤中的作用、导致肿瘤形成的机制及其在肿瘤诊断及预后中的作用作一综述。     

Masquerader: high mobility group box-1 and cancer.

Since its identification a third of a century ago, the high-mobility group box-1 (HMGB1) protein has been linked to varied diverse cellular processes, including release from necrotic cells and secretion by activated macrophages engulfing apoptotic cells. Initially described as solely chromatin-associated, HMGB1 was additionally discovered in the cytoplasm of several types of cultured mammalian cells 6 years later. In addition to its intracellular role, HMGB1 has been identified extracellularly as a putative leaderless cytokine and differentiation factor. In the years since its discovery, HMGB1 has also been implicated in disease states, including Alzheimer's, sepsis, ischemia-reperfusion, arthritis, and cancer. In cancer, overexpression of HMGB1, particularly in conjunction with its receptor for advanced glycation end products, has been associated with the proliferation and metastasis of many tumor types, including breast, colon, melanoma, and others. This review focuses on current knowledge and speculation on the role of HMGB1 in the development of cancer, metastasis, and potential targets for therapy.     

高迁移率族蛋白B-1与胃肠道肿瘤的相关性

高迁移率族蛋白B-1(HMGBl)是一种非组蛋白DNA结合蛋白和细胞外损伤相关模式分子,在正常情况下定位于细胞内,发挥多种生物学效应.研究证实,几乎所有的胃肠道肿瘤都有HMGBI的表达,且HMGBI表达与胃肠道肿瘤的生长、增殖、浸润和转移密切相关.研究还发现HMGB1抑制剂可抑制胃肠道肿瘤的生长和转移,有望成为胃肠道肿...     

High mobility group box 1 can be used to monitor perioperative course in patients with liver cancer

ObjectiveHigh mobility group box 1 (HMGB1) is produced by inflammation. Regarding liver injuries, HMGB1 is reportedly involved in liver regeneration. The present study investigated the use of HMGB1 as a postoperative marker of surgical course in patients with liver cancer.MethodsPatients were enrolled if they had liver cancer, had undergone liver surgery, and did not develop postsurgical complications. Patients who received emergency surgery or patients with unresectable cancerous lesions were excluded. Blood samples were preoperatively obtained as well as at 1 day, 1 week, and 4 weeks following surgery; white blood cell count, serum C-reactive protein, serum albumin, and serum HMGB1 levels were measured.ResultsA total of 36 patients were included in this study. HMGB1 levels significantly changed over time, increasing from a median of 7.1 ng/ml (preoperatively) to 13.9 ng/ml at 1 week postoperatively, and then decreased to 6.3 ng/ml at 4 weeks postoperatively. Peak HMGB1 levels were delayed, and elevated HMGB1 levels persisted as compared with the changes in conventional markers.ConclusionsHMGB1 indicates a unique perioperative inflammatory state in patients with liver cancer. Serum HMGB1 may serve as a marker for monitoring surgical course in patients undergoing surgery for liver cancer.