IGFBP-2 and Beta-Catenin makes brain tumour aggressive
Q. Which of the following is seen to be important in making a tumor aggressive?
1) IGFBP-2
2) Beta-catenin
3) Plakoglobin- Published on 30 May 16a. 2, 3
b. 1, 2
c. 1, 3
d. All of the above
ANSWER: 1, 2
- IGFBP-2 (insulin-like growth factor binding protein 2), one of the proteins present in the extracellular fluids surrounding the cells, makes the tumour aggressive.
- While previous studies have shown that patients with more aggressive forms of glioblastoma had higher IGFBP-2 levels in their serum, the IISc-NIMHANS study reveals that the IGFBP-2 uses the protein beta-catenin as its pathway.
- In glioblastoma cells with high levels of IGFBP-2 expression, nuclear beta-catenin levels were higher. In cells that made very little or no IGFBP-2, nuclear beta-catenin levels were low.
- Unlike IGFBP-2, which is present outside the cell, beta-catenin can shuttle in and out of the nucleus of the cell. When present inside, it influences protein production.
- The researchers found that higher IGFBP-2 levels led to inactivation of another protein — GSK3, which impairs the degradation of beta-catenin inside the cell. Hence, beta-catenin can easily travel to the nucleus and induce production of new proteins that instruct the tumour cells to proliferate faster than normal, and start invading other tissues.
