Secreted cyclophilin A mediates G1/S phase transition of cholangiocarcinoma cells via CD147/ERK1/2 pathway
Secreted cyclophilin A mediates G1/S phase transition of cholangiocarcinoma cells via CD147/ERK1/2 pathway
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DOI：
10.1007/s13277-014-2691-5
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发表时间：
2015-02-01
期刊：
影响因子：
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通讯作者：
Wongkham, Sopit
中科院分区：
文献类型：
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作者：
Obchoei, Sumalee;Sawanyawisuth, Kanlayanee;Wongkham, Sopit
亲环蛋白 A (CypA) 在人胆管癌 (CCA) 组织中表达上调。抑制细胞内 CypA (inCypA) 可显着降低体外细胞增殖和裸鼠肿瘤生长。本研究进一步研究了分泌型CypA（sCypA）对CCA细胞系增殖的影响及潜在机制。用含有 sCypA 的条件培养基 (CM) 或纯化的重组人 CypA (rhCypA) 处理 CCA 细胞。通过 MTS 测定、流式细胞术和蛋白质印迹检查细胞增殖、细胞周期、ERK1/2、p38 MAPK、NF-kappa B 和 STAT3 活性。在 MMNK1（永生化人胆管细胞系）和六种 CCA 细胞系的 CM 中检测到 sCypA。 sCypA 水平对应于 inCypA 水平，表明 sCypA 的细胞内起源。含有sCypA的CM和rhCypA均显着增加CCA细胞的增殖。通过shRNA敲低或用CD147单克隆抗体中和来消除CD147可显着减少sCypA和rhCypA介导的细胞增殖。 rhCypA 处理后，ERK1/2 迅速磷酸化；而中和 CD147 则抑制 ERK1/2 磷酸化。细胞周期分析显示，rhCypA 处理的细胞中 S 期显着增加，G1 期显着减少。与未处理的对照细胞相比，rhCypA处理的细胞中细胞周期蛋白D1和磷酸化视网膜母细胞瘤蛋白的表达水平增加。 p38 MAPK 通路在 siCypA 处理的细胞中被抑制。总之，CypA 由 CCA 细胞分泌，并以自分泌/旁分泌的方式增强细胞增殖，至少通过与 CD147 直接结合，这可能激活 ERK1/2 和 p38 MAPK 信号通路。
Cyclophilin A (CypA) was shown to be upregulated in human cholangiocarcinoma (CCA) tissues. Suppression of intracellular CypA (inCypA) significantly reduces cell proliferation in vitro and tumor growth in nude mice. In the present study, the effect and potential mechanism of secreted CypA (sCypA) on cell proliferation of CCA cell lines were further investigated. CCA cells were treated with sCypA-containing conditioned media (CM) or with purified recombinant human CypA (rhCypA). Cell proliferation, cell cycle, ERK1/2, p38 MAPK, NF-kappa B, and STAT3 activities were examined by MTS assay, flow cytometry, and Western blot. sCypA was detected in CM from MMNK1 (an immortalized human cholangiocyte cell line) and six CCA cell lines. The sCypA levels corresponded to the inCypA levels indicating the intracellular origin of sCypA. Both sCypA-containing CM and rhCypA significantly increased proliferation of CCA cells. CD147 depletion by shRNA-knockdown or neutralizing with a CD147-monoclonal antibody significantly reduced sCypA-, and rhCypA-mediated cell proliferation. Upon rhCypA treatment, ERK1/2 was rapidly phosphorylated; whereas neutralizing CD147 inhibited ERK1/2 phosphorylation. Cell cycle analysis showed a significant increase in S phase and decrease in G1 population in rhCypA-treated cells. The expression levels of cyclin D1 and phosphorylated-retinoblastoma protein in the rhCypA-treated cells were increased compared with those in the non-treated control cells. p38 MAPK pathway was shown to be suppressed in siCypA-treated cells. In summary, CypA is secreted from CCA cells and enhances cell proliferation in an autocrine/paracrine manner, at least via direct binding with CD147, which may activate the ERK1/2 and p38 MAPK signaling pathways.