, Volume 6, Issue 2, pp 59-70
Date: 31 Jan 2014

The PI3K/AKT/MTOR Signaling Pathway: The Role of PI3K and AKT Inhibitors in Breast Cancer

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


Breast cancer is the second leading cause of cancer death in women. Targeted therapies are available for HER2-positive and endocrine-sensitive disease while chemotherapy remains the mainstay of treatment for triple-negative breast cancer. The efficacy of all targeted interventions is, however, limited by primary or secondary resistance. Preclinical data show that active PI3K/AKT/mTOR signaling contributes to therapy resistance in HER2-positive and hormone-receptor-positive breast cancer. In line with these preclinical observations, clinical trials such as BOLERO-2 demonstrated a benefit of additional inhibition of mTOR signaling in advanced estrogen-receptor-positive breast cancer patients refractory to prior aromatase-inhibitor therapy. Besides the mTOR, several other proteins involved in the PI3K-pathway serve as potential therapeutic targets, such as PI3K and AKT. In this review, we summarize the current available knowledge and experimental and clinical research results about targeting the PI3K-pathway in breast cancer and, thus, provide the rationale for PI3K- and AKT-inhibitor use in the clinic.