Novel biomarkers in gastric cancer

The word “cancer” groups a series of diseases of different origin and different prognosis, with differentiated molecular mechanisms causing their onset and progression. Hence, discovery of novel biomarkers for each type of cancer, allowing to understand their underlying mechanisms and provide a specific (or even personalised) treatment is a fast-moving area of research.

In previous posts, we have described the finding of novel biomarkers for several types of cancer (e.g. esophageal, glioblastoma, pancreatic cancer, etc).  Let’s take a look today at gastric cancer.

An antibody array has recently been launched, allowing to detect and quantify the levels of 5 biomarkers associated to gastric cancer (CA19-9, CA72-4, CEA, Pepsinogen 1 and Pepsinogen 2). The array is not intended for clinical use, but rather, as a valuable tool to study cohorts of patients and see the levels of these biomarkers in serum and other types of samples, in order to validate them as future clinical markers.Untitled

CA19-9 is a glycosylated protein that has traditionally been considered as a tumour biomarker. It is not specific to gastric cancer, as it can also be present in pancreas cancer. It is useful, however, to monitor disease progression in some cases.

CA72-4 is another glyosylated protein, a bit more specific for gastric cancer than CA19-9, though it can also be present in some types of ovarian cancer.

Detection of CA19-9 and CA72-4 can be done adding CEA to the pannel, which increases the sensitivity and specificity from 42 % to 57 %. CEA (Carcinoembryonic antigen) groups a series of very similar glycoproteins involved in cell adhesion.

Finally, pepsinogens are clear indicators of gastric disease, and ratio between pepsinogen I and II can have a clinical significance for many gastric disorders. Combination of all these 5 biomarkers can be a good way to study gastric cancer in a more specific way.

Which model are you working on? If you’re interested this antibody array, or in any other arrays for your biomarkers of interest, get in touch!

 

 

High quality, low cost DNASeq kits and gene enrichment panels

Otogenetics' kits at tebu-bioOtogenetics Corporation, a DNASeq and RNASeq next generation sequencing service provider has processed over 11,000 samples and is now producing their own DNASeq kits. In order to reduce costs and improve results, Otogenetics developed and validated kits in-house and has now made these high quality, low cost kits available to other researchers.

[Read more…]

Tumour microenvironment – the kinome (II)

In a previous post, we discussed  kinome studies in the tumour microenvironment (TME). We described some solutions to study known markers, but we did not look at those cases in which the biomarkers associated to the kinome are unkown, and therefore some exploration is needed. [Read more…]

Novel biomarkers for esophageal cancer

As discussed in previous posts, use of new tools allows the finding of new disease-related biomarkers. Today, we want to put our spotlight on esophageal cancer.32_Q_Plex__multiplex_ELISA_by_Quansys

A recent alliance between Quansys Biosciences and Allegheny Health Network has allowed the development of a novel 4-plex assay for use in the early diagnosis of esophageal cancer. Though esophageal cancer is rare, it often has deadly outcomes. [Read more…]

How to get the most out of your biobank

For years, clinicians and researchers have gathered enormous collections of samples coming from different patients. These samples enable retrospective studies in order to better understand the mechanisms underlying a variety of diseases, helping to find novel biomarkers for early diagnosis, prognosis or evaluate the response to treatment. [Read more…]

Tumour microenvironment – exosomes

Following our series of posts on the tumour microenvironment (TME), we will put our spotlight today on exosomes.

TME-exosomes

Proposed immunological functions of tumour-derived exosomes. Taken from Ref. 3

TME is composed on myofibroblasts, extracellular matrix and many other cell types. The tumour communicates with its microenvironment through cytokines, growth factors, chemokines, miRNAs, etc, as previously seen. Exosomes are nanosized extracellular vesicles (EVs) that allow communication between cells. They seem to play a role in the progression of some cancers (e.g. prostate cancer, glioblastoma), as well as in resistance to cancer therapies (1, 2). In fact, they modulate the immune response, explaining their role in either fighting the tumour or helping the tumour cells evade the immune system (3). [Read more…]

Tumour microenvironment and miRNA biomarkers

In previous posts, we have seen the role of inflammation and glycosylation in the tumour microenvironment (TME). All these are mainly factors at the protein level causing the tumour cells to evade the immune system and metastasise. But what about other factors?

One of the areas that has raised quite some interest recently are microRNAs (miRNAs). If you’d like to brush up your knowledge on miRNAs, you might be interested in this post by my colleague Paola Vecino. miRNAs are becoming trendy, as they seem to be involved in several disease mechanisms (not only in cancer, but also in some other pathologies, including some inflammatory diseases), and they can be used as diagnostic and/or prognostic biomarkers.

[Read more…]

The best antibodies to detect FOX transcription factors

FOX transcription factor family members regulate the expression of genes known to play a critical role in embryonic development and organ morphogenesis. These “helix-turn-helix” class of proteins display a common “forkhead” motif and are encoded by Forkhead genes. Recent lines of evidences suggest that FOX proteins are promising therapeutical targets and biomarkers in various areas. A good opportunity to review of the most reliable FOX primary antibodies for research applications!

[Read more…]

See now how BRCA2 works to repair DNA

How BRCA2 works to repair damaged DNA.

Picture showing how BRCA2 proteins (red) help Red51 (yellow) form short filaments on strands of broken DNA (blue). This structure enables it to look for matching strands. (2)

A great discovery related to BRCA2 molecular mechanisms has been recently published in the October 2014 edition of Nature Structural and Molecular Biology. (1)

Funded by the Medical Research Council and the Wellcome Trust, a team of researchers have described for the first time the structure and the mechanism of action of the BRCA2 breast cancer tumor suppressor by electron microscopy.

Interestingly, the authors found that BRCA2 proteins work in pairs to facilitates Rad51-mediated homologous-recombination to repair DNA damaged. (see picture below)

A better understanding of the DNA repair processes will definitely help researchers in designing potent therapeutical approaches targeting molecular events involved in DNA integrity.

Want to know more about this BRAC2 picture and interactions with Rad51?

Here are the sources of this post:

  1. Shahid et al. ‘Structure and Mechanism of Action of the BRCA2 Breast Cancer Tumor Suppressor.’ Nature Structural and Molecular Biology, 5 October 2014. DOI:10.1038/nsmb.2899.

    BRCA2 representation

    BRCA2 representation. Study led by Professor Xiaodong Zhang from the Department of Medicine at Imperial College London and Dr Stephen West at the London Research Institute.

  2. First pictures of BRCA2 protein show how it works to repair DNA by Sam Wong

Feel free to leave a comment concerning the recent discoveries that impress you the most.

Tumor growth and metastasis monitored in vivo

In vivo monitoring of tumor growth and metastasis provides a powerful means for studying cancer properties and development of effective therapies. Mouse models created with tumor xenografts, resulting from subcutaneous or tail vein injection of cells, have long been used for such purposes. However, without a convenient means to visualize cancer progression in these animals, invasive surgical procedures are required in order to estimate the size and weight of primary and metastatic tumors, and cannot be used for early stages in tumor development. Surgery often requires sacrificing the animals, leading to the need for large numbers of individuals and increasing the cost and risk of sampling errors.

GeneCopoeia has recently announced the introduction of pre-made cancer cell lines labeled with GFP, and pre-made cancer cell lines dual-labeled with luciferase and GFP. A new powerful and sensitive mathods to follow tumor growth & metastasis in vivo! [Read more…]