Archive | March 2013

Iñaki Ruiz-Trillo and the origin of multicellularity

Hear biologist Iñaki Ruiz-Trillo explaining how his muliticellgenome lab is trying to understand the origin of multicellularity, i.e., the step from being a single cell to having trillions with differentiated functions. He works at the Institute for Evolutionary Biology (IBE:UPF-CSIC).

Assessing a new test for cervical cancer

Continuing with the issue of cervical cancer (you can read a previous post about virus-like particle (VLP)-based vaccines against this type of cancer), which is caused by high-risk human papillomavirus (HR-HPV), a group of researchers from the Pathology department of the Hospital del Mar (Parc de Salut MAR Biobanc), a reference laboratory for cervical cytology in Barcelona, have recently evaluated the clinical performance of a new HPV test (the cobas HPV Test).

Although the most widespread screening technique for cervical cancer is cytology (also called Papanicolaou test, or Pap smear), HPV detection has been proposed as an alternative, since it is more sensitive for the detection of precancerous lesions. However, compared to cytology, HPV testing has the risk of an excessive number of women without relevant lesions being referred for colposcopy.

 Hybrid capture 2 (HC2) is the current gold standard in HPV testing in cervical samples, but other tests have been recently launched, such as the cobas HPV Test. Since clinical sensitivity and specificity are decisive factors before the introduction of a new screening tool, the authors decided to evaluate the applicability of the new cobas HPV Test in the Catalan opportunistic screening protocol, which presently is based on cytology and HC2.

The study included samples from 958 women. According to the authors of this paper, published in PLoS One, the cobas HPV test system showed excellent results regarding both sensitivity and specificity, being at least as good as HC2. Both intralaboratory and interlaboratory reproducibility values were in the category considered almost perfect, overcoming the minimal requirements for a clinical test. The cobas HPV test has also proved to be a user-friendly system with high reproducibility and easy interpretation of results. It also has some advantages compared to HC2: it doesn’t require a specific procedure which takes time and increases the risk of contamination, and it contains an internal positive control (DNA amplification of cellular beta-globin).

“We feel confident that our results confirm a reliable clinical performance of cobas HPV Test allowing its introduction in cervical cancer screening protocols”, concludes correspondent author Sergi Serrano.

Reference:

Lloveras B, Gomez S, Alameda F, Bellosillo B, Mojal S, Muset M, Parra M, Palomares JC, Serrano S. HPV Testing by cobas HPV Test in a Population from Catalonia. PLoS One. 2013;8(3):e58153

Therapeutic virus-like particle- based vaccines against cervical cancer

Cervical cancer represents the second most frequent gynecological malignancy in the world. It is caused by a persistent virus infection by the high-risk human papillomavirus (HR-HPV) but no cervical cancer vaccine has been marketed to date. In a paper published in PLoS, Juan Martin Caballero, director of the PRBB animal facility, together with colleagues from a pharmaceutical company have generated a virus-like particle (VLP)-based vaccine to treat this cancer and have tested it in humanized transgenic mice.

The researchers took a long C-terminal fragment of the HPV-16 E7 protein – one of the two viral proteins necessary for induction and maintenance of malignant transformation – and introduced it into the infectious bursal disease virus (IBDV) VLP. The combination of tumor antigens and IBDV-VLPs has been shown as a good strategy to boost the immune response and direct it against different types of cancer.

The authors tested the therapeutic potential of their new vaccine, VLP-E7, in HLA-A2 humanized transgenic mice grafted with TC1/A2 tumor cells. They performed a series of tumour challenge experiments demonstrating a strong immune response against already formed tumors, including its complete eradication. Remarkably, therapeutic efficacy was obtained with a single dose without adjuvant and it persisted when the mice were re-challenged with a second tumor cell inoculation. As the authors state, this indicates a high immunogenic potential and in vivo efficacy of  their cervical cancer candidate vaccine, VLP-E7, although further studies will be necessary to investigate the potential of the IBDV VLP carrier and its applications to other human diseases.

Reference:

Martin Caballero J, Garzón A, González-Cintado L, Kowalczyk W, Jimenez Torres I, Calderita G, Rodriguez M, Gondar V, Bernal JJ, Ardavín C, Andreu D, Zürcher T, von Kobbe C. Chimeric Infectious Bursal Disease Virus-Like Particles as Potent Vaccines for Eradication of Established HPV-16 E7-Dependent Tumors. PLoS One. 2012;7(12):e52976

Environmental exposures and child health – a new European study

The official kick-off of the HELIX project (The Human Early-LIfe Exposome) will be taking place on March 11-13 at the PRBB, with public conferences in the Auditorium on the first day.

Coordinated by Martine Vrijheid from CREAL, HELIX has received €8.6M from the European Commission’s 7th Framework Programme. It aims to build an early life “Exposome”, a collection of all early-life environmental exposures affecting children, and it has 4 years and a half, from January 2013 to July 2017, to do so. HELIX will develop tools to measure the exposome, including the use of smartphones and biological markers.

The project involves 13 partners from eight European countries, including two SME’s and six birth cohort studies from France, Greece, Norway, Spain and the United Kingdom.

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