Ibrahim Safaa A, Katara Gajendra K, Kulshrestha Arpita, Jaiswal Mukesh K, Amin Magdy A, Beaman Kenneth D
Department of Microbiology and Immunology, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA.
Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Giza, Egypt.
Oncotarget. 2015 Oct 20;6(32):33033-45. doi: 10.18632/oncotarget.5439.
In invasive breast cancer, tumor associated neutrophils (TAN) represent a significant portion of the tumor mass and are associated with increased angiogenesis and metastasis. Identifying the regulatory factors that control TAN behavior will help in developing ideal immunotherapies. Vacuolar ATPases (V-ATPases), multi-subunit proton pumps, are highly expressed in metastatic breast cancer cells. A cleaved peptide from a2 isoform V-ATPase (a2NTD) has immunomodulatory role in tumor microenvironment. Here, we report for the first time the role of V-ATPase in neutrophils modulation. In invasive breast cancer cells, a2NTD was detected and a2V was highly expressed on the surface. Immunohistochemical analysis of invasive breast cancer tissues revealed that increased neutrophil recruitment and blood vessel density correlated with increased a2NTD levels. In order to determine the direct regulatory role of a2NTD on neutrophils, recombinant a2NTD was used for the treatment of neutrophils isolated from the peripheral blood of healthy volunteers. Neutrophils treated with a2NTD (a2Neuɸ) showed increased secretion of IL-1RA, IL-10, CCL-2 and IL-6 that are important mediators in cancer related inflammation. Moreover, a2Neuɸ exhibited an increased production of protumorigenic factors including IL-8, matrix metaloprotinase-9 and vascular endothelial growth factor. Further, functional characterization of a2Neuɸ revealed that a2Neuɸ derived products induce in vitro angiogenesis as well as increase the invasiveness of breast cancer cells. This study establishes the modulatory effect of breast cancer associated a2V on neutrophils, by the action of a2NTD, which has a positive impact on tumor progression, supporting that a2V can be a potential selective target for breast cancer therapy.
在浸润性乳腺癌中，肿瘤相关中性粒细胞（TAN）占肿瘤组织的很大一部分，且与血管生成增加和转移相关。确定控制TAN行为的调节因子将有助于开发理想的免疫疗法。液泡型ATP酶（V-ATP酶）是多亚基质子泵，在转移性乳腺癌细胞中高表达。来自a2亚型V-ATP酶的裂解肽（a2NTD）在肿瘤微环境中具有免疫调节作用。在此，我们首次报道了V-ATP酶在中性粒细胞调节中的作用。在浸润性乳腺癌细胞中，检测到a2NTD且a2V在表面高表达。浸润性乳腺癌组织的免疫组织化学分析显示，中性粒细胞募集增加和血管密度增加与a2NTD水平升高相关。为了确定a2NTD对中性粒细胞的直接调节作用，使用重组a2NTD处理从健康志愿者外周血中分离的中性粒细胞。用a2NTD处理的中性粒细胞（a2Neuɸ）显示白细胞介素-1受体拮抗剂（IL-1RA）、白细胞介素-10、趋化因子配体-2（CCL-2）和白细胞介素-6的分泌增加，这些都是癌症相关炎症中的重要介质。此外，a2Neuɸ表现出促肿瘤因子的产生增加，包括白细胞介素-8、基质金属蛋白酶-9和血管内皮生长因子。进一步的研究表明，a2Neuɸ衍生产物可诱导体外血管生成，并增加乳腺癌细胞的侵袭性。本研究证实了乳腺癌相关a2V通过a2NTD的作用对中性粒细胞具有调节作用，这对肿瘤进展有积极影响，支持a2V可能成为乳腺癌治疗的潜在选择性靶点。
