Getting SHIP-shape Over Tumour Suppression

Thu, 12/16/2010 - 07:53

PTEN antibodies have shown PTEN to be an important tumor suppressor and, in mutated form, a factor in cancer development. However, a recent study, led by Robert Rickert, shows that the SHIP gene may also be an important tumor suppressor in B-cell lymphomas. We at Novus Biologicals have an extensive range of PTEN and SHIP antibodies in our antibody catalog.

SHIP (SH2-containing inositol phosphatase) and PTEN (phosphatase and tensin homologue) antibodies are closely aligned, as both proteins have a similar function. PTEN is a lipid phosphatase which dephosphorylates phosphatidylinositol 3,4,5-trisphosphate (PIP3), forming phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2.) SHIP is a haemopoietic-specific phosphatase which also hydrolyzes PIP3, but at a different position, producing phosphatidylinositol-3, 4-bisphosphate, or PI(3,4)P2. Both function to negatively control cell growth and proliferation.

PIP3 activates the downstream signalling protein kinase AKT, a promoter of cell growth and division. Antibody studies have shown PTEN to negatively regulate the PI3k/AKT pathway via its action on PIP3. In this way it acts as a tumor suppressor. PTEN mutations are seen in a large number of cancers. In mouse experiments, T-cells lacking PTEN developed lymphomas.

Immunohistochemistry-Paraffin: PTEN

Rickert’s study looked at SHIP and PTEN activity with respect to B-cell lymphomas. It was seen that B-cells lacking either PTEN or SHIP remained normal. When both proteins were absent, however, lethal lymphomas developed. Earlier antibody studies had shown SHIP expression was reduced in the inflammatory response. It was suggested that PTEN mutation plus inflammation could lead to development of B-cell lymphomas, even where SHIP expression was otherwise normal. Depleted lymphoma cells also underwent proliferation in the absence of the prosurvival factor BAFF.

Taken together, the results indicate SHIP and PTEN act in unison to suppress B-cell lymphomas. Our PTEN/SHIP antibody database may prove vital in developing new cancer therapies.

Novus Biologicals offers many PTEN reagents for your research needs including:

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