title: Altered p-JAK1 expression is associated with estrogen receptor status in breast infiltrating ductal carcinoma.
abstract: The mammalian Janus kinase (JAK) family consists of four members, namely JAK1, JAK2, JAK3 and TYK2, which play a critical role in cytokine/growth factor signaling and is increasingly associated with human cancers. Aberrant activation of these non-receptor tyrosine kinases may contribute to carcinogenesis. Herein, we focused on exploring the potential role of p-JAK1 in breast cancer. The expression profiles of p-JAK1 were analyzed in 68 pairs of cancer and non-cancer breast tissues from the same infiltrating ductal carcinoma case by using immunoblotting technique. The results obtained were further correlated with clinicopathological characteristics. Intriguingly, p-JAK1 expression was decreased in 55.9% of breast cancer tissues as compared to the matched non-cancer tissues. Further immunohistochemistry study showed an intense p-JAK1 staining predominantly in adjacent normal breast tissues but not the matched cancer lesions. Decreased p-JAK1 expression in breast cancer tissues was significantly correlated with positive estrogen receptor (ER) status and increased tumor size (p=0.010 and 0.009). We also found that p-JAK1 expression was high in ERalpha-negative breast cancer cell lines but was low in ERalpha-positive breast cell lines. Transfection of ERalpha-positive MCF-7 cells with an ERalpha-specific siRNA upregulated the expression of p-JAK1. In summary, our results indicated that an altered p-JAK1 expression might be involved in the development of breast infiltrating ductal carcinoma in an ERalpha-related manner.
authors.affiliation: Department of Medical Research and Department of Obstetrics and Gynecology, E-DA Hospital, Kaohsiung, Taiwan, ROC.
authors.forename: Y T
authors.initials: YT
authors.lastname: Yeh
authors.forename: F
authors.initials: F
authors.lastname: Ou-Yang
authors.forename: I F
authors.initials: IF
authors.lastname: Chen
authors.forename: S F
authors.initials: SF
authors.lastname: Yang
authors.forename: J H
authors.initials: JH
authors.lastname: Su
authors.forename: M F
authors.initials: MF
authors.lastname: Hou
authors.forename: S S
authors.initials: SS
authors.lastname: Yuan
mesh_terms: D001943:Breast Neoplasms / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D004789:Enzyme Activation; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D053613:Janus Kinase 1 / Q000096:biosynthesis* / Q000378:metabolism; D009367:Neoplasm Staging; D010766:Phosphorylation; D011960:Receptors, Estrogen / Q000378:metabolism*
chemical_list: D011960:Receptors, Estrogen; C507904:JAK1 protein, human; D053613:Janus Kinase 1