Carbonic anhydrase XII mediates the survival and prometastatic functions of macrophages in human hepatocellular carcinoma
Wan-Ru Ning, Da Jiang, Xing-Chen Liu, Yu-Fan Huang, Zhi-Peng Peng, Ze-Zhou Jiang, Tiebang Kang, Shi-Mei Zhuang, Yan Wu, Limin Zheng
Wan-Ru Ning, Da Jiang, Xing-Chen Liu, Yu-Fan Huang, Zhi-Peng Peng, Ze-Zhou Jiang, Tiebang Kang, Shi-Mei Zhuang, Yan Wu, Limin Zheng
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Research Article Immunology Metabolism

Carbonic anhydrase XII mediates the survival and prometastatic functions of macrophages in human hepatocellular carcinoma

Abstract

Macrophages constitute a major immune component in tumor tissues, but how these cells adapt to and survive in the nutrient-depleted and lactic acid–induced acidic tumor microenvironments is not yet fully understood. Here, we found that levels of carbonic anhydrase XII (CA12) expression were significantly and selectively upregulated on macrophages in human hepatocellular carcinoma (HCC). Transient glycolytic activation of peritumoral monocytes induced sustained expression of CA12 on tumor-infiltrating macrophages via autocrine cytokines and HIF1α pathways. On the one hand, CA12 mediated the survival of macrophages in relatively acidic tumor microenvironments, while on the other hand, it induced macrophage production of large amounts of C-C motif chemokine ligand 8 (CCL8), which enhanced cancer cell epithelial-mesenchymal transition (EMT) and facilitated tumor metastasis. Consistently, the accumulation of CA12+ macrophages in tumor tissues was associated with increased tumor metastatic potential and reduced survival of patients with HCC. Selective targeting of tumor-infiltrating macrophages with a CA12 inhibitor reduced tumor growth in mice and was sufficient to synergistically enhance the therapeutic efficacy of immune-checkpoint blockade. We suggest that CA12 activity is a previously unappreciated mechanism regulating the accumulation and functions of macrophages in tumor microenvironments and therefore represents a selective vulnerability that could be exploited in future designs for antitumor immunotherapeutic strategies.

Authors

Wan-Ru Ning, Da Jiang, Xing-Chen Liu, Yu-Fan Huang, Zhi-Peng Peng, Ze-Zhou Jiang, Tiebang Kang, Shi-Mei Zhuang, Yan Wu, Limin Zheng

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Figure 1

CA12 is selectively upregulated on tumor-infiltrating monocytes and macrophages and correlates with disease progression.

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CA12 is selectively upregulated on tumor-infiltrating monocytes and macr...
(A) CD14+ cells were purified from paired nontumor (N) and tumor tissues (T) from 3 patients with HCC. The levels of CD14+ cell αCA family gene expression were quantified by qPCR. (B) CD14+ and CD14– leukocytes were purified from paired nontumor and tumor tissues from HCC patients. Levels of CA12 expression in these cells were quantified by qPCR (n = 5). (C) Frozen sections of HCC samples were stained with an anti-human CD68 antibody (red), an anti-human CA12 antibody (green), and DAPI (blue). The colocalization and distribution of cell signals were analyzed by confocal microscopy. Scale bar: 50 μm. One out of five representative micrographs from 5 independent experiments is shown. (D) CD14+ and CD14– leukocytes were purified from paired nontumor, peritumor (P), and tumor tissues from HCC patients. The levels of CA12 expression in these cells were determined by immunoblotting (n = 3). (E) Fresh leukocytes were isolated from paired nontumor, peritumor, and tumor tissues from HCC patients. Levels of CA12 expression on CD14+ and CD14– leukocytes were determined by flow cytometry (n = 6). (F) Seventy-two HCC patients who underwent curative resection with follow-up data were divided into 2 groups according to the median value of CD68+ or CD68+CA12+ cell density in tumor tissues (CD68+ cells: low, ≤391 cells/mm2 [n = 35]; high, >391 cells/mm2 [n = 37]; CD68+CA12+ cells: low, ≤278 cells/mm2 [n = 35]; high, >278 cells/mm2 [n = 37]). The OS and TR of these patients were analyzed via the Kaplan-Meier method and log-rank test. Results shown in B and E are represented as mean ± SEM. P values were obtained by paired 2-tailed Student’s t test (B), 1-way ANOVA (E), or log-rank test (F). **P < 0.01; ***P < 0.001.