We observed that TIS21<sup>/BTG2</sup> inhibited mTORc1 activity by reducing Raptor-mTOR interaction along with upregulation of tsc1 expression, which lead to significant reduction of p70S6K activation as opposed to AKT1<sup>S473</sup>, but not AKT2, phosphorylation via downregulating PHLPP2 (AKT1-specific phosphatase) in breast cancers.
Collectively, the results of this study reveal novel LAM biomarkers linked to breast cancer metastasis to lung and to cell stemness, which in turn might guide the assessment of additional or complementary therapeutic opportunities for LAM.
Recent data suggest that functional inactivation of TSC proteins might also be involved in the development of other diseases not associated with TSC, such as sporadic bladder cancer, breast cancer, ovarian carcinoma, gall bladder carcinoma, non-small-cell carcinoma of the lung, and Alzheimer's disease.