Clinical Laboratory, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China.
Department of Infection Management, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei 050011, P.R. China.
Mol Med Rep. 2017 Oct;16(4):5633-5642. doi: 10.3892/mmr.2017.7306. Epub 2017 Aug 21.
Interleukin 24 (IL‑24) is a unique cytokine encoded by the melanoma differentiation associated gene‑7 (Mda‑7), and was first discovered inhuman melanoma cells. Exogenous Mda‑7/IL‑24 has been shown to inhibit the proliferation and invasion of a broad spectrum of human cancer cells, but its effect on the differentiation of B cell lymphoma is not yet clear. To the best of our knowledge, the present study demonstrated for the first time that overexpressing Mda‑7/IL‑24 can induce differentiation in human B cell lymphomacells, and the underlying mechanism was investigated. The proliferation of stable Mda‑7/IL‑24 overexpressing Raji and Daudi cells was assessed by the MTS method. The immunophenotype, apoptosis level and cell cycle distribution of Raji and Daudi cells were analyzed by flow cytometry. The expression of PR domain zinc finger protein 1 (Blimp1) and B‑cell lymphoma 6 (Bcl6) were analyzed by western blotting. Additionally, western blotting assay was also performed to study the effect of Mda‑7/IL‑24 on the activity of the P38 mitogen activated protein kinase (MAPK) signaling pathway in Raji and Daudi cells. Proliferation of Raji and Daudi cells overexpressing Mda‑7/IL‑24 was inhibited significantly, compared with those of parent cells and cells transfected with the empty vector alone. Apoptosis was not involved in the proliferation inhibition, while the cell cycle was arrested in G1 phase in the Raji and Daudi cells overexpressing Mda‑7/IL‑24. Overexpressing Mda‑7/IL‑24 resulted in a significantly decreased expression of cluster of differentiation (CD)10, and increased expression of CD45 and CD138 in the cell surface of Raji and Daudi cells. The expression of Blimp1 was upregulated, while the levels of Bcl6 protein was downregulated, in Raji and Daudi cells overexpressing Mda‑7/IL‑24. Furthermore, the activities of the P38 MAPK signaling pathway in lymphoma cells were upregulated. These results indicated that Mda‑7/IL‑24 could induce terminal differentiation of B lymphoma cells by regulating the expression of Blimp1 and Bcl6 via altering the P38 MAPK signaling pathway, suggesting that Mda‑7/IL‑24 may therefore be a potential differentiation therapeutic agent to be applied in clinical treatment of B cell lymphoma.
白细胞介素 24（IL-24）是一种由黑色素瘤分化相关基因 7（Mda-7）编码的独特细胞因子，最初在人类黑色素瘤细胞中发现。外源性 Mda-7/IL-24 已被证明能抑制广谱人类癌细胞的增殖和侵袭，但它对 B 细胞淋巴瘤的分化影响尚不清楚。据我们所知，本研究首次证明过表达 Mda-7/IL-24 可诱导人类 B 细胞淋巴瘤细胞分化，并探讨了其潜在机制。通过 MTS 法评估稳定过表达 Mda-7/IL-24 的 Raji 和 Daudi 细胞的增殖情况。通过流式细胞术分析 Raji 和 Daudi 细胞的免疫表型、凋亡水平和细胞周期分布。通过蛋白质印迹法分析 PR 结构域锌指蛋白 1（Blimp1）和 B 细胞淋巴瘤 6（Bcl6）的表达。此外，还通过蛋白质印迹法研究了 Mda-7/IL-24 对 Raji 和 Daudi 细胞中 P38 丝裂原活化蛋白激酶（MAPK）信号通路活性的影响。与亲本细胞和单独转染空载体的细胞相比，过表达 Mda-7/IL-24 的 Raji 和 Daudi 细胞的增殖明显受到抑制。增殖抑制不涉及细胞凋亡，而过表达 Mda-7/IL-24 的 Raji 和 Daudi 细胞的细胞周期被阻滞在 G1 期。过表达 Mda-7/IL-24 导致 Raji 和 Daudi 细胞表面的分化群（CD）10 表达显著降低，而 CD45 和 CD138 的表达增加。过表达 Mda-7/IL-24 的 Raji 和 Daudi 细胞中 Blimp1 的表达上调，而 Bcl6 蛋白水平下调。此外，淋巴瘤细胞中 P38 MAPK 信号通路的活性上调。这些结果表明，Mda-7/IL-24 可能通过改变 P38 MAPK 信号通路调节 Blimp1 和 Bcl6 的表达，诱导 B 淋巴瘤细胞的终末分化，提示 Mda-7/IL-24 可能是一种有潜力的分化治疗药物，可应用于 B 细胞淋巴瘤的临床治疗。
