Phosphorylation studies made with Antibody Arrays

Oropharyngeal squamous cell carcinomas (OSCCs) can be either Human papillomavirus (HPV)-positive or HPV-negative. Profiles of druggable Receptor Tyrosine Kinases (RTKs) are different in both groups, as shown in a paper by Cortelazzi, B. et al. The authors chose a cohort of 17 HPV-positive and 59 HVP-negative Formalin-Fixed OSCCs, in order to study E5 expression and RTK alterations. RTK activation was explored in further 12 Frozen OSCCs.

HPV-positive and HPV-negative OSCCs showed different RTK profiles, including differences in E5 and HER2 levels, as well as in HER3 activation and heterodimerisation (HER3/EGFR, also seen for HER2/EGFR). PI3KCA mutations/expression/increased gene copy number and PTEN mutations were found in both groups, whereas PTEN gene loss was only observed in the HPV-positive cases.

The authors stated that, for HPV-positive cases, it would be interesting to study the expression of E5, which may modulate EGFR turnover and activate VEGF and PDGFRβ. They also indicate that in HPV-negative cases, HER3 may be a promising druggable biomarker that would deserve further investigation. Finally, PI3KCA and PTEN alterations encourage the promising clinical evaluation of PI3K/mTOR inhibitor activity in OSCCs, particularly in HPV-positive/PI3KCA-mutated OSCCs.

This study was possible in part thanks to an approach based on arrays to detect multiple biomarkers in biological samples at the same time, followed by validation using simplex technologies. These experimental approaches are known for cytokine profiling but also exist for phosphorylation studies (RTKs, EGFR, mTOR phospho-pathways…).

To ensure top quality in the data obtained, you might outsource your biomarker profiling and validation to certified service providers fully trained. tebu-bio: European RaybioTech's Certified Laboratory service provider

In Europe, tebu-bio laboratories (France) were among the first laboratories in the world to be certified by Raybiotech in 2012 but also by Quansys BioSciences and FullMoon BioSystems technologies. The Biomarkers team will be proud to support you to publish novel discoveries by providing innovative discovery & validation tools.

Genetic fingerprint of aggressive colon tumours

1.organoides_tumorales_de_pacientes

Patient-derived tumour organoids (mini colon tumours). In blue: cellular nuclei; in red: cellular membranes (Image: Alexandre Calon, IRB Barcelona).

Researchers at the IRB in Barcelona have found a signature of 4-6 genes able to predict the aggressivity of colon tumours, by analysing the tissue surrounding the tumour cells.

The scientists are currently developing a test that enables the identification of patients at risk of relapse after surgical removal of the tumour by measuring these found genes. They also propose to test in patients a particular drug that blocks the metastatic capacity of colorectal cancers in mice. This drug has been already tested using organoids derived from patients’ samples.

Source:

On a more funny note, have a look at the video done this last summer by researchers at the IRB Barcelona!

Any exciting research (or videos!) done over at your laboratory or institute?

We would like to know!

3 validated tools for ubiquitination studies

Elongation of ubiquitin chains, regardless of the linkage, can form polyubiquitin fibrils to initiate the Autophagy pathway. A deficiency of the autophagy causes cytotoxic accumulation of ubiquitin-positive aggregates leading thus  to neurodegenerative diseases (1). A new deubiquitinating enzyme, USP36, highly expressed in human breast and lung cancers, was identified to regulate c-Myc oncoprotein stability in nucleolus. (2) Also, Itch, an E3 HECT Ubiquitin ligase, inhibits MAPK p38α activation through ubiquitylation can be exploited therapeutically to prevent chronic skin inflammation (3). A recent publication by Yumimoto K. et al. determined that expression of FBXW7, the F-box Protein of SCF Ubiquitin Ligase, can suppress cancer metastasis in either non-cell-autonomous or cell-autonomous manner. (4)

Ub proteolysis pathway

Ub and F-box proteins proteolysis pathways.

 

Immunohistochemistry staining of formalin-fixed paraffin-embedded human lung using FBXW7 monoclonal antibody (3ug/ml) (Cat. No. 157H00055294-M02).

Immunohistochemistry staining of formalin-fixed paraffin-embedded human lung using FBXW7 monoclonal antibody (3ug/ml) (Cat. No. 157H00055294-M02).

In this work, researchers used the anti FBXW7 monoclonal antibody  to perform immuno-cyto-chemical staining on breast tissues.

Other tools to study ubiquitination include the use of Tandem Ubiquitin Binding Entities (TUBES) for the isolation and detection of polyubiquitylated proteins. TUBES can be used, in combination with Anti Linear Polyubiquitin antibody to investifgate Uquitin linkages on substrates.

References

  1. Morimoto, D., et.al. (2015). Nature communications. DOI: 10.1038/ncomms7116.
  2. Sun, X.-X., et.al. (2015). PNAS. DOI: 10.1073/pnas.1411713112.
  3. Theivanthiran, B., et.al. (2015). Science. DOI: 10.1126/scisignal.2005903.
  4. Yumimoto, K., et.al. (2015) JCI. DOI: 10.172/JCI78782.

If you are studying the role of ubiquitin and ubiquitination in your model, please leave your comment!

Cancer stem cells – friend or foe in the fight against cancer?

Today, following our series on Tumour Microenvironment (TME), and leading on from three recent publications, let’s discuss Cancer Stem Cells (CSCs).

CSCs are part of the TME, as they reside in niches where they can survive from immune surveillance, maintain plasticity and facilitate cancer metastasis (1). They can also circulate around the body. Which makes them so interesting. Their worse effect is that they can expand cancer to other organs in the body, thus helping metastasic. The good thing is that their early detection is a very powerful biomarker for cancer, allowing an early treatment. [Read more…]

From osteoarthritis to bladder cancer… hyaluronic acid is not just cosmetics!

Hyaluronic Acid (HA) is important in many biological processes such as wound repair, tissue hydration and inflammation. HA is also a potential biomarker for diseases such as osteoarthritis, liver cirrhosis and bladder cancer. So its importance as a prognostic / diagnostic / predictive biomarker is still to be elucidated… but it might be present even when you don’t expect it!

Hyaluronan (HA) is a linear polysaccharide comprised of a repeating disaccharide of N-acetylglucosamine and D-glucuronic acid. The major function of HA is to provide structural support of tissue as part of the extracellular matrix (ECM). Thus, HA is widely presented in connective tissue in higher animals. The size of HA varies from 100 kD to 10,000 kD and is responsible for different functions. [Read more…]

DNA repair antibodies validated by MD Anderson

A series of publications (1, 2) in the past months has raised the never-ending debate on commercial antibodies and their validity in a given experiment. At tebu-bio, having sold antibodies for more than 40 years, we are well aware that not all antibodies fit all applications, and always strive to find the best antibody for a given experiment.

In collaboration with the MD Anderson Cancer Center, Rockland Inc. has developed and validated a highly specific toolkit to analyze PARP1 in a panel of control and siRNA knockdown cell lysates by multiple immunoassays. [Read more…]

mTOR revisited

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Figure taken from Ref. 1.

The PI3K/Akt/mTOR pathway is an intracellular signaling pathway important in regulating the cell cycle. It is directly related to cellular quiescence, proliferation, cancer, and longevity. This pathway can be regulated by genes involved in response to hypoxia. Discoveries that have been made over the last decade show that the mTOR pathway is activated during various cellular processes (e.g. tumour formation and angiogenesis, insulin resistance, adipogenesis and T-lymphocyte activation) and is deregulated in human diseases such as cancer and type 2 diabetes (1). [Read more…]

New Clinical Research trends in Oncology

A symposium on trends in Clinical Oncology was recently held in Madrid, Spain. The symposium gathered actors from the private health system (Hospital Madrid – Clara Campal, Onkologikoa, Clínica Universidad de Navarra), as well as pharmaceutical companies (Roche, Novartis).

The interest of this symposium is that it had a look at the research on cancer from the perspective of clinicians coming from private hospitals, and not from the National Health Systems. [Read more…]

Discovery of functional serum biomarkers

Lung cancer is one of the most common malignancies, and the leading cause of cancer-related fatality. Current diagnostic practices for common cancers rely heavily on imaging technologies. These methods are quite accurate, but still have a probability of having false-positive findings. Also, there is a substantial need for non-invasive ways to test whether the nodules are benign or malignant.

Blood-based biomarkers have potential in cancer screening, and their role could extend further from general population risk assessment to treatment response evaluation and recurrence monitoring. However, despite much research effort, biomarkers able to predict disease onset and evolution are not always easy to find, or distinctive enough. [Read more…]

PBMCs & drug development

Use of human samples including peripheral blood mononuclear cells (PBMCs) in drug discovery is critical for increasing the chances of success for a small molecule screen hit. A review based on recent published data!

PBMCs DD 1Several theories try to explain why many drug discovery and development projects have a moderate success rate. Even with the advances made in methods (HTS, HCA, library managment, etc), there are many hurdles for a small molecule on the long road to FDA or EMA approval.

One way that may improve predicted efficacy and toxicity of drug leads is to use human samples, such as blood, early on in drug discovery programs. Peripheral blood mononuclear cells  (PBMCs) can be easily used in a variety of ways during the drug discovery process to gain a better understanding of the effects of a small molecule. [Read more…]