Predictive pathology of cytostatic drug resistance and new anti-cancer targets

Integrative genomics identifies gene signature associated with melanoma ulceration

Background

Despite the extensive research approaches applied to characterise malignant melanoma, no specific molecular markers are available that are clearly related to the progression of this disease. In this study, our aims were to define a gene expression signature associated with the clinical outcome of melanoma patients and to provide an integrative interpretation of the gene expression -, copy number alterations -, and promoter methylation patterns that contribute to clinically relevant molecular functional alterations.

Methods

Gene expression profiles were determined using the Affymetrix U133 Plus2.0 array. The NimbleGen Human CGH Whole-Genome Tiling array was used to define CNAs, and the Illumina GoldenGate Methylation platform was applied to characterise the methylation patterns of overlapping genes.

Results

We identified two subclasses of primary melanoma: one representing patients with better prognoses and the other being characteristic of patients with unfavourable outcomes. We assigned 1,080 genes as being significantly correlated with ulceration, 987 genes were downregulated and significantly enriched in the p53, Nf-kappaB, and WNT/beta-catenin pathways. Through integrated genome analysis, we defined 150 downregulated genes whose expression correlated with copy number losses in ulcerated samples. These genes were significantly enriched on chromosome 6q and 10q, which contained a total of 36 genes. Ten of these genes were downregulated and involved in cell-cell and cell-matrix adhesion or apoptosis. The expression and methylation patterns of additional genes exhibited an inverse correlation, suggesting that transcriptional silencing of these genes is driven by epigenetic events.

Conclusion

Using an integrative genomic approach, we were able to identify functionally relevant molecular hotspots characterised by copy number losses and promoter hypermethylation in distinct molecular subtypes of melanoma that contribute to specific transcriptomic silencing and might indicate a poor clinical outcome of melanoma.

Targeting cancer stem cells with monoclonal antibodies: a new perspective in cancer therapy and diagnosis

This review discusses some of the impacts that biotechnology, genomics and nanotechnology convergence should have on future cancer management, in particular, the development of innovative diagnostic and therapeutic approaches based on monoclonal antibodies (mAbs) and cancer stem cells. Emergent therapeutic strategies in cancer have been focusing on the use of mAbs to stimulate an immune response against tumors, to block signaling pathways, or to refine delivery of cytotoxic agents. Now that cancer stem cells are being identified and characterized in different tumor types, their relevance to cancer physiopathology is becoming evident, making them natural targets for mAb development. Cancer stem cells are postulated to be responsible for tumor development, metastasis and relapse after conventional therapies. Therefore, mAbs targeting specific antigens and related pathways altered in cancer stem cells should facilitate earlier diagnosis through molecular imaging techniques and more efficient destruction of tumor initiating cells, thus improving clinical outcome.

Where we publish : an analysis of the publications of German institutes of pathology

Pathologists provide the link between the clinical and the natural science aspect of medicine and are often integrated in translational research projects. We wanted to analyse the spread and position of research led by pathologists in the scientific literature. Publications from institutes of pathology of 21 randomly chosen German university cities between 2004 and 2006 were analysed. To validate our findings we subsequently extended our analysis to 45 university cities from Italy, France and the Nordic countries (Denmark, Finland, Iceland, Norway and Sweden). We detected publications directed by pathologists in numerous biomedical journals, most of which not categorised as "pathology" journals. In the analyses from Germany and Italy, Virchows Archiv led the ranking in terms of absolute number of publications. Meanwhile, Anticancer Research and the International Journal of Cancer took the lead concerning publications from pathologists from the Nordic countries. Our results mirror the wide diversification in scientific pathology and the overlap with other medical subspecialties, especially oncology, cell biology and biochemistry. This explains the problem of defining "pathology" journals and deducting pathological research activity from these publications. However, the general notion that pathology journals are the most important communication medium of pathology research was affirmed.