Blogs for June 2010: Novus Biologicals

HnRNP Antibodies Shed New Light on Fight Against Gastric Cancer

Monday, June 28, 2010 - 10:00

We at Novus Biologicals offer many antibodies relevant to cancer research. Among the areas covered by our antibody catalog are the nuclear matrix proteins, which include the heterogeneous nuclear ribonucleoproteins (hnRNPs). hnRNP antibodies were recently used in a new study in gastric cancer treatment.

The nuclear matrix is a filamentous and complex network of proteins and RNA fibrils, comprising the fibrous nuclear lamina and numerous nuclear pores. The matrix acts to provide a structural framework for the organization of chromatin (the genetic component of the cell). Once thought to be a fairly static structure, antibodystudies have shown matrix proteins play a dynamic role, interacting freely with chromatin. HnRNP proteins, for example, are involved in various nuclear activities, including pre-mRNA processing, mRNA translation and transcription.

The human nuclear cell matrix has been shown to be tumor specific. The nuclear...

Transcription Factor Antibodies Used In Landmark Evolutionary Study

Friday, June 25, 2010 - 10:00

We at Novus Biologicals offer a full antibody database targeted to transcription factor research. Recently, CEBP antibodieswere used in a research study exploring the evolution of gene regulation in various vertebrates. The results revealed surprising discrepancies between genomes, and the conservation of transcription factor function over large evolutionary distances.

Transcription factors bind to specific regulatory areas of DNA sites, and direct gene expression by the activation or inhibition of RNA polymerases. They may act independently, or as part of a larger protein complex. The diversity of genes within the animal kingdom means a vast number of transcription factors exist. We at Novus Biologicals have over 2,300 transcription factor-related products in our antibody catalog, with many more yet to be identified.

...

The Link Between Base Excision Repair and Cancer Antibodies

Wednesday, June 23, 2010 - 10:00

Base excision repair (BER) is the most fundamental DNA repair mechanism, dealing with alterations arising in individual DNA bases during cellular metabolism. We at Novus Biologicals have a large BER antibody database, which has proven important in various cellular studies.

BER has been shown to be the predominant repair mechanism in post-mitotic areas such as brain tissue. Here, modifications of single bases are far more likely to occur than large-scale damage to the DNA helix. Levels of base excision repair proteins have been shown to be elevated or altered in certain cancers, for example prostate cancer and brain tumors.

The two main routes of base excision repair are the long-patch and short-patch repair pathways. Both follow the same 4 basic steps, and although the protein pathways are independent of each other,...

NER, BER, HR and Other DNA Repair Pathways

Monday, June 21, 2010 - 10:00

A large number of antibody assays are devoted to the study of nuclear excision repair (NER) proteins. However, there are a number of other DNA repair pathways, many of which are instigated by NER and share the same proteins. DNA repair antibodies are widely used in cancer research, and Novus Biologicals offers an extensive selection of thoroughly validated, high-quality DNA repair and cancer related antibodies.

NER is subdivided into global repair, which repairs damage to any part of the DNA structure, and transcription-coupled repair, which preferentially recognises damage in an area where simultaneous transcription is occurring. The mechanism by which this occurs is still not fully understood, though it is known that XPC is essential. Antibodystudies have shown that damage recognition and repair can be initiated by blocking RNA polymerase II, assisted by the Cockayne’s syndrome genes...

Blocking 53BP1 Expression Lessens Tumor Development in BRCA1-Defective Mice

Friday, June 18, 2010 - 10:00

Our antibody database at Novus Biologicals provides research tools for the forefront of cancer research. Recently, a mouse study using 53BP1 and BRCA1 antibodies showed that deletion of 53BP1 greatly lessened the incidence of tumor development in mice carrying the mutated BRCA1 gene.

The BRCA1 protein is important in the homologous recombination (HR) DNA repair pathway, repairing the replication-associated chromosome breaks which can occur during cell division. If the HR pathway becomes inactive through BRCA1 mutation, the cell relies on alternative repair pathways. However, these are more mutagenic than BRCA1, and can cause formation of abnormal chromosome structures, increasing the risk of cancer. 53BP1 is a binding protein, known to localize to DNA repair sites, in particular double-strand breaks. However, it is not thought to be mutagenic.

A study carried out by...

Using PCNA as an Antibody Marker

Wednesday, June 16, 2010 - 10:00

PCNA antibodies are useful biomarkers in DNA repair studies. PCNA is one of several proteins essential for the completion of nucleotide excision repair, a multi-stage process involving 20 - 30 proteins, and an important factor in repairing damage and mutations to the DNA helical structure. We at Novus Biologicals have an extensive NER antibody database, which is used in research that includes Cockayne’s Syndrome, XP (Xeroderma Pigmentosum), and cancer and chemotherapy research.

NER is initiated by recognition of the damage and occurs via two routes, global and transcription-coupled. Global is the more common, involving the XPE and XPC complementing proteins, RD23B and centrin 2. From stage 2 onwards NER becomes a single pathway process.

...

NER Antibodies in Cancer Research

Monday, June 14, 2010 - 10:00

We at Novus Biologicals have over 230 products in our antibody catalog devoted to nucleotide excision repair. NER is a multi-stage sequential process involving over 30 proteins, all of which have been widely studied. Being the primary method to repair DNA damage caused by agents ranging from UV radiation to chemotherapy drugs, our NER antibody database is widely used by cancer research groups.

The first stage of NER is damage recognition and demarcation. There are two main pathways: global genomic repair and transcription-coupled repair. Global repair involves the Xeroderma Pigmentosum complementing proteins XPC and DDB1 (XPE), and the RD23B–centrin 2 complex, which recognize the damage by forming a heterotrimeric complex. Transcription-coupled repair occurs in genes that are being actively transcribed by RNA pol II. The...

DNA Repair Pathways Prove Important for Cancer Research

Friday, June 11, 2010 - 10:00

The mammalian DNA repair process encompasses a large number of protein pathways, and forms an important part of our antibody catalog. The past 30 years have seen tremendous advances in the understanding of these mechanisms, with Wood, et al. recently compiling an updated inventory of at least 150 human DNA-repair proteins. This added considerably to the scope of the antibody database of us at Novus Biologicals.

Among the major repair pathways for mammalian DNA are: simple damage reversal; recombination repair; base excision repair (BER) and nucleotide excision repair (NER).

...

The Benefits Of Lightning-Link Direct Antibody Labeling

Monday, June 7, 2010 - 10:00

The typical way of detecting proteins by immunohistochemical staining involves a two-step process. A primary antibody is raised against the antigen, and then a second, fluorescently-labeled antibody is used to detect the first.

Evidently, a one-step staining method would be far simpler and quicker than the indirect method. However, until recently direct conjugation has been avoided because of problems in sensitivity and amplification of the signal. Factors influencing this include the sample size needed, low percentage of recovery and dilution. The indirect method has greater sensitivity, as the signal can be amplified through using several secondary antibodies, each specific to a different antigenic site on the primary protein. However, the procedure is tedious, requiring numerous incubation and wash steps. Using secondary proteins also means more likelihood of cross-over problems and non-specific binding.

We at Novus Biologicals supply...

Novus Customer Focus - The Nelson Lab of ASU's Biodesign Institute

Tuesday, June 1, 2010 - 14:10

Dr. Randall Nelson and his Molecular Biomarkers Lab Team are the topic of this week's Novus Customer Focus. At Arizona State University's Biodesign Institute, Dr. Nelson and his lab conduct biomarker research to investigate and understand how biomarkers function and how they can be used in medical applications.

The Nelson Lab studies biomarkers using a unique methodology called mass spectrometry immunoassay (MSIA). MSIA uses both Matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) and Electrospray Ionization (ESI). This multiplex approach allows for the fast and accurate analysis of several specific proteins and their variants at the same time. MSIA allows Dr. Randall and his team to accurately identify amino acid sequences of small and large proteins, as well as these proteins' post-translational modifications and changes in concentrations, collectively termed ' microheterogeneity'. The capability of...