前沿科技及其它

The ability to isolate relatively pure populations of primary normal and malignant lymphocytes has brought studies of lymphoid malignancies to the forefront of cancer research. Apoptosis (programmed cell death) plays a key role in controlling normal B-cell numbers, and resistance to ...

The E1B-55 kDa oncoprotein of adenovirus type 5 targets the tumor suppressor protein p53. This includes four distinct activities: (i) biochemical interaction of E1B-55 kDa with p53; (ii) inhibition of p53-induced transcription; (iii) relocalization of p53 from the nucleus to the cytopla ...

p53 is a sequence-specific DNA binding protein. The p53 consensus is two copies of 5′-RRRC(A/T)(T/A)GYYY-3′. The interaction of p53 with specific DNA binding sites (DBS) has been analyzed extensively using electrophoretic mobility shift analysis (EMSA). These studies do not address the int ...

Until recently, the accepted model held that p53 degradation occurs exclusively on cytoplasmic proteasomes and, hence, has an absolute requirement for nuclear export of p53 via the CRM1 pathway. However, proteasomes are abundant in both cytosol and nucleus. We recently analyzed HDM2-m ...

p53 is a master regulator of cell death pathways and has transcription-dependent and transcription-independent modes of action. Mitochondria are major signal transducers in apoptosis and are critical for p53-dependent cell death. Recently, we discovered that a fraction of stress ...

The p53 protein is a key player in the cellular response to stress conditions. Activation of p53 induces growth inhibition in the form of cell growth arrest or apoptosis. The latter plays an important role in the tumor suppression function of p53. It is therefore of great interest to understand in deta ...

Although MDM2, the product of mouse double minute-2 (mdm2) gene, or its human homologue possesses the potential to confer tumorigenic properties, it induces G1/S arrest in nontransformed cells. Flow cytometry provides a way to determine the effects of MDM2 on the cell cycle by expressing the pr ...

Mutation in the p53 gene is the most frequently found genetic abnormality in human tumors, resulting in increased resistance to chemo- and radiotherapy (1,2). The underlying rationale for p53-mediated cancer gene therapy is to restore the ability of p53 mutant tumors to undergo apoptosis. W ...

p53 is one of the most well-characterized members of the tumor suppressor gene family. The role of p53 in controlling cellular homeostasis has proven critical, with over half of all human tumors having either lost or mutated p53. The emergence of technology facilitating the ablation of a gene with ...

We describe a method for purifying recombinant p53 from baculovirus infected cells in one step by anion exchange chromatography. The p53 is full-length with no flanking sequences and its expression is driven by the baculovirus polyhedron promoter. We also describe how to concentrate the p ...

Differential display (DD) is a method used worldwide for identifying differentially expressed genes in eukaryotic cells. The mRNA DD technology works by systematic amplification of the 3′ terminal regions of mRNAs. Using anchored primers designed to bind 5′ boundary of the polyA tails for ...

Real-time quantitative polymerase chain reaction (QPCR) using the Roche LightCycler� was used to verify the expression of asparagine synthetase (ASNS) identified by microarray analysis as a target of p53 transrepression and mutant p53 transactivation. A p53-null cell line derived ...

Researchers in the p53 field have successfully used many high-throughput screening technologies to analyze and characterize p53-induced gene expression. This chapter will focus on one such technology, the Affymetrix GeneChip�. DNA-Chip technology has grown rapidly over the last ...

The methods outlined in this chapter are designed to facilitate the study of the transactivation and transrepression properties of p53 (as well as p63 and p73). Once a gene of interest is identified, its presumptive promoter region can be cloned upstream of a luciferase gene in a plasmid. The most com ...

There is substantial evidence in the literature that, in addition to functioning as an activator of transcription, the p53 tumor suppressor protein can also function as a sequence-specific transcriptional repressor of a separate set of genes. However, elucidation of the mechanism whe ...

Cellular proteins that interact with p53 play a major role in both positive and negative regulation of this tumor suppressor and can fine-tune its response to specific cellular stresses. As a consequence, p53 biology will not be complete until these interacting proteins are fully characte ...

Cytogenetics plays an important role in the diagnosis of acute lymphoblastic leukaemia (ALL), particularly in relation to the association of specific chromosomal abnormalities with outcome. The karyotype at diagnosis is used in the risk stratification of patients for treatment w ...

In chronic lymphocytic leukemia of the B-lineage (B-CLL), cytogenetic alterations are highly relevant for prognosis and therapeutic decisions. With conventional techniques, chromosome banding analysis in CLL has been hampered by the low quality of metaphases and low rates of cytog ...

Antibodies enable relatively simple, rapid, and reproducible studies to be performed on protein expression in both normal and neoplastic cells. The availability of suitable reagents for routine diagnostic use has revolutionized the study of leukemia and lymphoma pathology. The use ...

Tumor-specific chromosomal abnormalities are attracting a large interest owing to the diagnostic, prognostic, and therapeutic importance. The development of molecular techniques, e.g., fluorescence in situ hybridization (FISH), have improved the detection of specific chr ...