title: mTOR in breast cancer: differential expression in triple-negative and non-triple-negative tumors.
abstract: Triple-negative breast cancer (TNBC) is defined by the absence of estrogen receptors (ER), progesterone receptors (PR) and overexpression of HER2. Targeted therapy is currently unavailable for this subgroup of breast cancer patients. mTOR controls cancer cell growth, survival and invasion and is thus a potential target for the treatment of patients with TNBC. Using immunohistochemistry, mTOR and p-mTOR were measured in 89 TNBCs and 99 non-TNBCs. While mTOR expression was confined to tumor cell cytoplasm, p-mTOR staining was located in the nucleus, perinuclear area and in the cytoplasm. Potentially important, was our finding that nuclear p-mTOR was found more frequently in triple-negative than non triple-negative cancers (p < 0.001). These results suggest that mTOR may play a more important role in the progression of TNBC compared to non-TNBC. Based on these findings, we conclude that mTOR may be a new target for the treatment of triple-negative breast cancer.
authors.affiliation: UCD School of Medicine and Medical Science, Conway Institute, University College Dublin, Dublin, Ireland.
authors.forename: S
authors.initials: S
authors.lastname: Walsh
authors.forename: L
authors.initials: L
authors.lastname: Flanagan
authors.forename: C
authors.initials: C
authors.lastname: Quinn
authors.forename: D
authors.initials: D
authors.lastname: Evoy
authors.forename: E W
authors.initials: EW
authors.lastname: McDermott
authors.forename: A
authors.initials: A
authors.lastname: Pierce
authors.forename: M J
authors.initials: MJ
authors.lastname: Duffy
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D058570:TOR Serine-Threonine Kinases; C546842:MTOR protein, human; C508053:ERBB2 protein, human