Tumor Suppressor Gene Missing in Triple Negative Breast Cancer
Posted May 02 2011 10:03am
Triple negative breast cancer (TNBC) remains one of the more aggressive forms of breast cancer. Because of the lack of hormone receptors, triple negative breast cancers do not respond to hormone therapy or HER2 therapy. Standard therapy for TNBC remains mainly limited to surgery, radiation therapy, and chemotherapy, particularly in light of the FDA's earlier recommendation to ban the use of bevacizumab for TNBC . Nonetheless, research into safe and effective triple negative breast cancer treatment continues to show promise .
New triple negative breast cancer research recently published in the journal Cell appears to have identified a tumor suppressor gene involved in TNBC development and progression. In this new study, breast cancer researchers used a genetic screening process to examine gene changes in triple negative breast cancer cells. The investigators identified the gene PTPN12 as potent tumor suppressor gene that appears to be linked to TNBC. The researchers reported
The PTPN12 gene powerfully inhibits the growth of breast cells and their transformation into cancer cells.
PTPN12 functions by blocking the action of multiple growth factor enzymes involved in breast cancer development and progression.
The PTPN12 gene is frequently inactivated in triple negative breast cancer cells, thereby preventing it from blocking tumor suppression.
Restoration of PTPN12 functionality inhibits the metastatic potential of TNBC cells.
The tumorigenic and metastatic ability of TNBC cells can also be inhibited by blocking the growth factor enzymes normally blocked by the PTPN12 gene.
These are exciting breast cancer research results with the potential to lead to new therapies for triple negative breast cancer. The results of this study clearly indicate that this tumor suppressor gene is inactivated in many triple negative breast cancer cells and that re-activating this gene reduces the activity of these breast cancer cells. Breast cancer treatments designed to re-activate this gene or to block the enzymes this gene normally suppresses might prove to be effective ways to improve the outcomes for patients diagnosed with triple negative breast cancer.