Wang Zhu, Yang Yang, Cui Yancheng, Wang Chao, Lai Zhiyong, Li Yansen, Zhang Wei, Mustonen Harri, Puolakkainen Pauli, Ye Yingjiang, Jiang Kewei, Shen Zhanlong, Wang Shan
Department of Gastroenterological Surgery, Peking University People's Hospital, Beijing 100044, China.
Laboratory of Surgical Oncology, Beijing Key Laboratory of Colorectal Cancer Diagnosis and Treatment Research, Peking University People's Hospital, Beijing 100044, China.
Chin J Cancer Res. 2020 Feb;32(1):72-88. doi: 10.21147/j.issn.1000-9604.2020.01.09.
Recent studies have shown that tumor-associated macrophages (TAMs) play an important role in cancer invasion and metastasis. Our previous studies have reported that TAMs promote the invasion and metastasis of gastric cancer (GC) cells through the Kindlin-2 pathway. However, the mechanism needs to be clarified.
THP-1 monocytes were induced by PMA/interleukin (IL)-4/IL-13 to establish an efficient TAM model and M2 macrophages were isolated via flow cytometry. A dual luciferase reporter system and chromatin immunoprecipitation (ChIP) assay were used to investigate the mechanism of transforming growth factor β2 (TGFβ2) regulating Kindlin-2 expression. Immunohistochemistry was used to study the relationships among TAM infiltration in human GC tissues, Kindlin-2 protein expression, clinicopathological parameters and prognosis in human GC tissues. A nude mouse oncogenesis model was used to verify the invasion and metastasis mechanisms .
We found that Kindlin-2 expression was upregulated at both mRNA and protein levels in GC cells cocultured with TAMs, associated with higher invasion rate. Kindlin-2 knockdown reduced the invasion rate of GC cells under coculture condition. TGFβ2 secreted by TAMs regulated the expression of Kindlin-2 through the transcription factor NF-кB. TAMs thus participated in the progression of GC through the TGFβ2/NF-κB/Kindlin-2 axis. Kindlin-2 expression and TAM infiltration were significantly positively correlated with TNM stage, and patients with high Kindlin-2 expression had significantly poorer overall survival than patients with low Kindlin-2 expression. Furthermore, Kindlin-2 promoted the invasion of GC cells .
This study elucidates the mechanism of TAMs participating in GC cell invasion and metastasis through the TGFβ2/NF-κB/Kindlin-2 axis, providing a possibility for new treatment options and approaches.
近期研究表明，肿瘤相关巨噬细胞（TAM）在癌症侵袭和转移中起重要作用。我们之前的研究报道，TAM通过Kindlin-2通路促进胃癌（GC）细胞的侵袭和转移。然而，其机制尚需阐明。
用佛波酯（PMA）/白细胞介素（IL）-4/IL-13诱导THP-1单核细胞建立高效TAM模型，并通过流式细胞术分离M2巨噬细胞。采用双荧光素酶报告系统和染色质免疫沉淀（ChIP）试验研究转化生长因子β2（TGFβ2）调节Kindlin-2表达的机制。采用免疫组织化学研究人GC组织中TAM浸润、Kindlin-2蛋白表达、临床病理参数及预后之间的关系。用裸鼠成瘤模型验证侵袭和转移机制。
我们发现，与TAM共培养的GC细胞中，Kindlin-2在mRNA和蛋白水平均上调，且侵袭率更高。敲低Kindlin-2可降低共培养条件下GC细胞的侵袭率。TAM分泌的TGFβ2通过转录因子NF-κB调节Kindlin-2的表达。因此，TAM通过TGFβ2/NF-κB/Kindlin-2轴参与GC的进展。Kindlin-2表达和TAM浸润与TNM分期显著正相关，Kindlin-2高表达患者的总生存期明显低于Kindlin-2低表达患者。此外，Kindlin-2促进GC细胞的侵袭。
本研究阐明了TAM通过TGFβ2/NF-κB/Kindlin-2轴参与GC细胞侵袭和转移的机制，为新的治疗选择和方法提供了可能性。
