Tumor cells often are seen to express glycoproteins, which can serve as markers especially those which have sialic acid as their sugar moiety.
Recently American scientists have reported bio-orthogonal labeling test for sialylated glycoproteins based on a glycoproteomics approach which assesses the sialylated glycoproteins levels in tumor cell membranes. This has been reported in a very famous journal Angewandte Chemie. This assay identifies up- or downregulated proteins directly in the prostate cancer tissue, instead of just identifying the level of sialylated glycans in the tumor cells.
Tumor cells are very different from the normal cells. They have accelerated levels of metabolism taking place and thus producing proteins up- and some down-regulated. As a lot can be determined about the proteins like their quantity, and quality by these assay techniques, of proteomic research, scientist seek to use a proteomics test system to identify and explore the proteins typical for cancer metabolism. Bertozzi and her research team from Stanford University have chosen a bioorthogonal labeling strategy to identify sialylated glycoproteins. This sialic acid sugar moiety helps cells to evade the immune system.
One very interesting aspect of this bioorthogonal labeling is that it does very little interference with the normal metabolism of the cell. As in this technique, a fluorescent molecule is chemically attached to target molecules, which can then be identified by bioimaging or mass spectrometry.
The cultures are chosen from live human tumor tissue, because “prostate tissue slice cultures, allow direct comparisons of cancerous and normal tissue from the same patient source.” This is the major source of obtaining a culture.
In the technique, the cultures are treated with an azide-modified sialic acid, which was readily integrated into the tumor cell metabolism. Next, a fluorescent label was chemically attached to the azide group. After labeling and cell lysis, the culture slices are inspected into mass spectrometry or by imaging. On observation, clear differences were spotted between a normal, and cancer cell. In the cancer cell, proteins up or down-regulated were identified. Merging this platform with existing glycoproteome analysis techniques as future options. This can lead to a major discovery in understanding, and treating cancer, thus leading mankind to a cancer-free future. The research prospects are evolving as ever, and now understanding cancer is not a far away dream.