Transparent zebrafish provides new insight into breast cancer.November 14th, 2007 - 2:42 am ICT by admin
The two proteins identified by the researchers are vascular endothelial growth factor (VEGF) and Rhoc. While the former is made by cancerous cells and stimulates new blood vessel formation, the latter is involved in cell movement or migration and is overexpressed in highly metastatic forms of breast cancer.
Dr. Stoletoy has revealed that the two proteins promote metastasis by allowing cancerous breast tumours to enter the blood vessels. He says that neither VEGF nor RhoC alone interact with blood vessels to allow the cancerous tumour to enter the blood vessels (also known as intravasate), “but together, they promote rapid intravasation.”
For their study, the researchers developed an immuno-suppressed zebrafish that expresses green fluorescent protein (commonly known as GFP) only in its blood vessels, so that it would enable them to view the tumour-induced blood vessel formation.
The fish was injected with IBC cells tagged in different colours to study the very rapid tumour progression. While the parental cancer cells were tagged in blue, and the migrating cells that over-expressed RhoC were tagged in red.
The researchers watched the cancer’s progression over several weeks by using high resolution, multi-colour confocal microscopy.
They discovered that RhoC induces an amoeboid-like mode of invasion, in which the cancerous cells move by means of temporary projections or ‘false feet’. They also found that secretion of VEGF was required in order for the cancer cells to penetrate and enter the blood vessel.
“In later stages of the cancerous tumour, the VEGF induces rapid formation of irregular, leaky blood vessels. We discovered that intravasation requires the secretion of VEGF, which disrupts the blood vessel wall, creating small openings that allow the tumour cells to penetrate and enter,” said Dr. Stoletov.
Dr. Richard Klemke, professor of pathology at UCSD School of Medicine and the UCSD Moores Cancer Center who led this study, believes that finding a way to suppress VEGF, and thus inhibiting the growth of “leaky” blood vessels, may stop the movement of cancer cells into the blood vessels and the tumour’s subsequent metastasis.
The transparency of the fish model in the study also enabled researchers to image and analyse, in three dimensions, images of a potential anti-cancer compound that inhibits the VEGF compound.
They say that the inhibitor prevents the formation of the vascular openings, and thereby inhibits intravasation. (ANI)
- Molecules that help propel cancer metastasis identified - Apr 08, 2011
- Novel method might help block for tumour growth - Mar 15, 2011
- Scientists discover protein that arrests cancer-spreading enzyme - Jan 04, 2011
- Key culprit in breast cancer metastasis identified - Feb 17, 2011
- Scientists find new way to 'starve' cancer cells - Apr 05, 2011
- Possible clues to tamoxifen resistance in breast cancer patients found - Mar 31, 2011
- Overabundance of protein promotes growth of breast cancer stem cells - Feb 16, 2011
- Key protein controlling blood vessel growth in mice's brain identified - Nov 12, 2010
- How breast cancer cells dodge immune system and survive - Feb 02, 2011
- Biophysicist attempts to block protein to prevent breast, prostate cancer - Apr 20, 2011
- Hormone therapies 'up breast cancer metastasis risk in post-menopausal women' - May 07, 2010
- Key enzyme that controls growth of breast cancer cells identified - Nov 19, 2010
- Parsley could help in breast cancer treatment - May 10, 2011
- Possible biomarker and therapeutic target for melanoma identified - Mar 18, 2011
- Targeting protein helps keep melanoma tumour growth in check - Dec 10, 2010
Tags: blood vessel formation, blood vessels, breast tumours, cancer cells, cancerous breast, cancerous cells, cancerous tumour, confocal microscopy, false feet, human breast cancer, metastasis, national academy of science, proceedings of the national academy of science, proteins, tagged, they discovered that, transgenic zebrafish, uc san diego, vascular endothelial growth factor, vegf