PDL1 Regulation by p53 via miR-34
PDL1 Regulation by p53 via miR-34
复制标题
DOI：
10.1093/jnci/djv303
复制
发表时间：
2016-01-01
影响因子：
10.3
通讯作者：
Welsh, James W.
中科院分区：
文献类型：
--
作者：
Cortez, Maria Angelica;Ivan, Cristina;Welsh, James W.
背景资料：尽管临床研究显示靶向PD 1/PDL 1信号转导在非小细胞肺癌（NSCLC）中的前景，但对PDL 1表达的调控知之甚少。方法：采用p53野生型和p53缺陷型细胞系（p53（-/-）和p53（+/+）HCT 116、p53诱导型H1299和p53敲低型H460），检测p53是否通过miR-34调控PDL 1。在来自肺癌癌症基因组图谱（TCGA LUAD）的NSCLC和突变型p53与野生型p53肿瘤患者的样本中分析了PDL 1和miR-34 a表达。我们通过蛋白质印迹和荧光素酶测定证实了PDL 1是miR-34的直接靶点，并使用p53（R172 H Delta）g/+K-ras（LA 1/+）同基因小鼠模型（n = 12）递送miR-34 a负载脂质体（MRX 34）加放疗（XRT），并评估PDL 1表达和肿瘤浸润淋巴细胞（TIL）。结果：我们发现p53通过miR-34调节PDL 1，miR-34在NSCLC模型中直接与PDL 1 3'非翻译区结合（荧光素酶活性相对于对照组的倍数变化，miR-34 a的平均值= 0.50，SD = 0.2，P <0.001; miR-34 b的平均值= 0.52，SD = 0.2，P = 0.006; miR-34 c的平均值= 0.59，SD = 0.14，P = 0.006）。MRX 34的治疗性递送，目前是I期临床试验的主题，（对照组CD 8表达百分率均值= 22.5%，SD = 1.9%; MRX 34的平均CD 8表达百分比= 30.1%，SD = 3.7%，P = 0.016，n = 4）和体内CD 8（+）PD 1（+）细胞减少（对照组CD 8/PD 1表达百分率均值= 40.2%，SD = 6.2%; MRX 34的CD 8/PD 1表达百分比的平均值= 20.3%，SD = 5.1%，P = .001，n = 4）。此外，MRX 34 + XRT增加的CD 8+细胞数量多于任一单独治疗（MRX 34 + XRT的CD 8表达百分比平均值为对照组的44.2%，SD = 8.7%，P = 0.004，n = 4）。最后，miR-34 a的递送减少了辐射诱导的巨噬细胞的数量。（对照组F4-80表达百分比的平均值= 52.4%，SD = 1.7%; MRX 34的F4-80表达百分比的平均值= 40.1%，SD = 3.5%，P = 0.008，n = 4）和T调节细胞。我们确定了一种新的机制，通过这种机制，肿瘤免疫逃避受到p53/miR-34/PDL 1轴的调节。我们的研究结果表明，使用标准疗法（如XRT）递送miRNA可能代表了肺癌的一种新治疗方法。
Background: Although clinical studies have shown promise for targeting PD1/PDL1 signaling in non-small cell lung cancer (NSCLC), the regulation of PDL1 expression is poorly understood. Here, we show that PDL1 is regulated by p53 via miR-34.Methods: p53 wild-type and p53-deficient cell lines (p53(-/-) and p53(+/+) HCT116, p53-inducible H1299, and p53-knockdown H460) were used to determine if p53 regulates PDL1 via miR-34. PDL1 and miR-34a expression were analyzed in samples from patients with NSCLC and mutated p53 vs wild-type p53 tumors from The Cancer Genome Atlas for Lung Adenocarcinoma (TCGA LUAD). We confirmed that PDL1 is a direct target of miR-34 with western blotting and luciferase assays and used a p53(R172H Delta)g/+K-ras(LA1/+) syngeneic mouse model (n = 12) to deliver miR-34a-loaded liposomes (MRX34) plus radiotherapy (XRT) and assessed PDL1 expression and tumor-infiltrating lymphocytes (TILs). A two-sided t test was applied to compare the mean between different treatments.Results: We found that p53 regulates PDL1 via miR-34, which directly binds to the PDL1 3' untranslated region in models of NSCLC (fold-change luciferase activity to control group, mean for miR-34a = 0.50, SD = 0.2, P < .001; mean for miR-34b = 0.52, SD = 0.2, P = .006; and mean for miR-34c = 0.59, SD = 0.14, and P = .006). Therapeutic delivery of MRX34, currently the subject of a phase I clinical trial, promoted TILs (mean of CD8 expression percentage of control group = 22.5%, SD = 1.9%; mean of CD8 expression percentage of MRX34 = 30.1%, SD = 3.7%, P = .016, n = 4) and reduced CD8(+)PD1(+) cells in vivo (mean of CD8/PD1 expression percentage of control group = 40.2%, SD = 6.2%; mean of CD8/PD1 expression percentage of MRX34 = 20.3%, SD = 5.1%, P = .001, n = 4). Further, MRX34 plus XRT increased CD8+ cell numbers more than either therapy alone (mean of CD8 expression percentage of MRX34 plus XRT to control group = 44.2%, SD = 8.7%, P = .004, n = 4). Finally, miR-34a delivery reduced the numbers of radiation-induced macrophages (mean of F4-80 expression percentage of control group = 52.4%, SD = 1.7%; mean of F4-80 expression percentage of MRX34 = 40.1%, SD = 3.5%, P = .008, n = 4) and T-regulatory cells.Conclusions: We identified a novel mechanism by which tumor immune evasion is regulated by p53/miR-34/PDL1 axis. Our results suggest that delivery of miRNAs with standard therapies, such as XRT, may represent a novel therapeutic approach for lung cancer.