Advances in Microarray Technology Conference Biggest Ever

The Advances in Microarray Technology Conference, the fourth in the Select BioSciences AMT events, held in Barcelona May 7-8, 2008 was well attended, with more than 400 participants, around 40 exhibitors and a full two-day programme.

The event took place in the well-equipped Catalunya Congress Palace in Barcelona, and the nearby Hotel Rey Juan Carlos.

Simultaneous “Lab-on-a-chip” and “Advances in Biodefense Technology” meetings were held in neighbouring rooms.

Three sessions dealt with “Microarray diagnostics”, “Microarray technology” and “Tissue microarrays” and will be described below. There was also an extensive and well-attended poster section.

• The microarray diagnostics session (one full day) included useful overviews of market opportunities and trends (Steven Bodovitz, BioPerspectives, and Kenneth Krul, BioTechTelligence), highlighting the active development of multiplexed diagnostics and their fairly strong acceptance (from a survey of developers and potential users), while underlining the need for valid follow-up studies and extensive physician education.

Potential molecular diagnostics submarkets were discussed in some detail, with a positive outlook for personalized treatment in contrast to disease susceptibility studies. An overview of technical and clinical issues in DNA array diagnostics (Bertrand Jordan, Marseille-Nice Genopole) discussed the different categories of tests (genotyping vs. expression profiling), and indicated the reasons for their relatively slow acceptance – lack of proof of real clinical utility in a number of cases, as well as cost issues.

This session then presented several varieties of array diagnostics: array CGH for diagnosis of constitutional abnormalities (Karoly Szuhai, Leiden University Medical Center), on the way to replacing karyotypes in clinical practice, CNV (Copy Number Variation) analysis using tiling arrays (Herbert Auer, Institute for Research in Biomedicine, Barcelona), miRNA arrays and the steps necessary to obtain meaningful results (Stefan Wild, Miltenyi Biotech).

Towia Liberman (Beth Israel Med Center, Harvard) discussed the transition from expression profiling to biomarkers, and a useful overview of non-coding RNAs (that go much beyond miRNAs) was given by Antje Kretzschmar (Fraunhofer Institute, Leipzig). Label-free blood typing was described by Holger Schulze (University of Edinburgh), and Michael Tainsky (Wayne State University School of Medicine) showed the use of panels of tumor antigens to detect autoantigens in cancer; he also detailed the difficulties in obtaining biomarkers with sufficient sensitivity and specificity.

Levi Gheber (Ben-Gurion University) described initial steps towards the development of portable arrayed biosensors with microfabrication technology. The session also included corporate presentations: Veronique Mainfroid (Eppendorf), and Peter Roberts (Febit Biomed), the latter highlighting the extreme flexibility of the Geniom system for miRNA studies. Other corporate presentations (in other sessions) described the Arrayjet high-throughput printing system (Ian McWilliam), and Invitrogen’s efforts towards developing protocols allowing arrayCGH experiments using DNA extracted from paraffin-embedded tissue samples (Ernie Guzman).

• The microarray technology session (one morning) was mostly devoted to protein microarrays. A presentation by Thomas Joos (University of Tubingen) showed the variety of systems already available and advocated using off-the-shelf technology whenever possible.

“Reverse phase” protein arrays (in which cell or tissue lysates are spotted and then probed with specific antibodies) were discussed by Ulrike Korf (DKFZ, Heidelberg), using infrared dyes for arrays investigating protein expression in cancer, and by John Austin (Aushon Biosystems) who showed the advantages of solid pin systems for manufacture of arrays with “difficult-to-spot” entities such as proteins or cell lysates.

Tatyana Nasedkina (Engelhard Institute, Moscow) described wide adoption for clinical diagnostics (within the Russian Federation) of the gel pad array system originally developed by Andrei Mirzabekov.

Finally, Steve Blair (University of Utah) gave a very interesting (if somewhat frightening) talk on the complexities and pitfalls of multiplex hybridization on microarrays, raising serious doubts on what exactly is measured in some experiments…

• The last (afternoon) session was centered on tissue microarrays, a clinically important application that (wrongly) appears to be low-tech and is rarely discussed in depth. The analysis of tissue arrays after reaction with specific antibodies (immunohistochemistry) is done manually in a very labor and time-intensive fashion, and attempts to automate it meets many challenges: the data is very complex and expert human judgment seems absolutely necessary.

Stephen Hewitt (NCI, NIH) highlighted the importance of this approach for cancer diagnosis and prognosis, and insisted on the higher relevance of protein biomarkers compared to gene expression signatures. A realistic approach to automation of tissue array procedures was described by Donal O’Shea (SlidePath Ltd), stressing partial automation and the importance of assisting the expert rather than attempting to replace him. Very advanced image analysis procedures developed by Definiens (Münich) were shown by Johannes Zimmerman, with quite striking examples.

The Human Protein Atlas project was reported by Frederik Ponten (University of Uppsala). This programme is presently producing 3,000 highly specific antibodies against human proteins every year (with a team of 80 co-workers) and is making them widely available. This very useful undertaking is on the way to removing one to the major blocks to protein array studies and biomarker discovery, namely the limited availability of good antibodies.

In summary, this was on the whole a good, informative and lively meeting, very valuable to get an update on current technology and projects as well as on clinical applications – and also useful, of course, for networking and business discussions. The delegate mix (about half academia, half industry) was quite good, although it would be nice to attract a few more high-level academic scientists.

In future editions, it would probably be advisable to include one or two talks discussing applications in which arrays are in competition with next-generation sequencing approaches, this would help to see the respective strengths and weaknesses of the two technologies.

In terms of organization, the schedule was fine, quite intensive while still allowing enough time for discussion and for viewing the exhibition as well as the posters. If possible, it would be nice to integrate the poster area with the commercial exhibition – this would further enhance interactions. The organization was faultless and the provision of an open WiFi connection on the meeting grounds was a welcome addition.