Open AccessRapamycin inhibits BAFF-stimulated cell proliferation and survival by suppressing mTOR-mediated PP2A-Erk1/2 signaling pathway in normal and neoplastic B-lymphoid cells
Author(s) -
Qingyu Zeng,
Hai Zhang,
Jiamin Qin,
Zhigang Xu,
Lin Gui,
Beibei Liu,
Chunxiao Liu,
Chong Xu,
Wen Liu,
Shuangquan Zhang,
Shile Huang,
Long Chen
Publication year - 2015
Publication title -
cellular and molecular life sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.928
H-Index - 223
eISSN - 1420-9071
pISSN - 1420-682X
DOI - 10.1007/s00018-015-1976-1
Subject(s) - pi3k/akt/mtor pathway , b cell activating factor , cancer research , cell growth , signal transduction , protein phosphatase 2 , microbiology and biotechnology , protein kinase b , biology , rptor , chemistry , b cell , immunology , phosphorylation , phosphatase , biochemistry , antibody
B-cell activating factor (BAFF) is involved in not only physiology of normal B cells, but also pathophysiology of aggressive B cells related to malignant and autoimmune diseases. Rapamycin, a lipophilic macrolide antibiotic, has recently shown to be effective in the treatment of human lupus erythematosus. However, how rapamycin inhibits BAFF-stimulated B-cell proliferation and survival has not been fully elucidated. Here, we show that rapamycin inhibited human soluble BAFF (hsBAFF)-induced cell proliferation and survival in normal and B-lymphoid (Raji and Daudi) cells by activation of PP2A and inactivation of Erk1/2. Pretreatment with PD98059, down-regulation of Erk1/2, expression of dominant negative MKK1, or overexpression of wild-type PP2A potentiated rapamycin's suppression of hsBAFF-activated Erk1/2 and B-cell proliferation/viability, whereas expression of constitutively active MKK1, inhibition of PP2A by okadaic acid, or expression of dominant negative PP2A attenuated the inhibitory effects of rapamycin. Furthermore, expression of a rapamycin-resistant and kinase-active mTOR (mTOR-T), but not a rapamycin-resistant and kinase-dead mTOR-T (mTOR-TE), conferred resistance to rapamycin's effects on PP2A, Erk1/2 and B-cell proliferation/viability, implying mTOR-dependent mechanism involved. The findings indicate that rapamycin inhibits BAFF-stimulated cell proliferation/survival by targeting mTOR-mediated PP2A-Erk1/2 signaling pathway in normal and neoplastic B-lymphoid cells. Our data highlight that rapamycin may be exploited for preventing excessive BAFF-induced aggressive B-cell malignancies and autoimmune diseases.