PMID- 32948650 OWN - NLM STAT- MEDLINE DCOM- 20211014 LR - 20211014 IS - 2051-1426 (Electronic) IS - 2051-1426 (Linking) VI - 8 IP - 2 DP - 2020 Sep TI - Targeted delivery of miR-99b reprograms tumor-associated macrophage phenotype leading to tumor regression. LID - 10.1136/jitc-2019-000517 [doi] LID - e000517 AB - BACKGROUND: Accumulating evidence has shown that tumor-associated macrophages (TAMs) play a critical role in tumor progression. Targeting TAMs is a potential strategy for tumor immunotherapy. However, the mechanism underlying the TAM phenotype and function needs to be resolved. Our previous studies have demonstrated that miR-125a can reverse the TAM phenotype toward antitumor. Meanwhile, we have found that miR-125a and miR-99b cluster in the first intron of the same host gene, and are transcribed simultaneously in bone marrow-derived macrophages (BMDMs) following LPS+IFNgamma stimulation. However, it remains unclear whether miR-99b by itself can exert an antitumor effect by regulating macrophage phenotype. METHODS: miR-99b and/or miR-125a were delivered into TAMs of orthotopic hepatocellular carcinoma (HCC) or subcutaneous Lewis lung cancer (LLC) mice. The effect of treatment was evaluated by live imaging, TUNEL staining and survival tests. The phenotype of the immune cells was determined by qRT-PCR, ELISA, western blot and FACS. The capability of miR-99b-mediated macrophage phagocytosis and antigen presentation was detected by FACS and immunofluorescence staining. The underlying molecular mechanism was examined by qRT-PCR, reporter assay and western blot, and further verified in the tumor model. The expression of miR-99b and its target genes was determined in TAMs sorted from tumor and adjacent tissues in patients with liver cancer. RESULTS: Targeted delivery of miR-99b and/or miR-125a into TAMs significantly impeded the growth of HCC and LLC, especially after miR-99b delivery. More importantly, the delivery of miR-99b re-educated TAM toward antitumor phenotype with enhanced immune surveillance. Further investigation of mechanisms showed that macrophage-specific overexpression of miR-99b promoted M1 while suppressing M2 macrophage polarization by targeting kappaB-Ras2 and/or mTOR, respectively. miR-99b-overexpressed M1 macrophage was characterized by stronger capability of phagocytosis and antigen presentation. Additionally, delivery of simTOR or sikappaB-Ras2 into TAMs inhibited miR-99b antagomir-triggered tumor growth. Finally, miR-99b expression was lower in TAMs of patients with liver cancer than that in adjacent tissues, while the expression of kappaB-Ras2 and mTOR was reversed. CONCLUSIONS: Our results reveal the mechanism of miR-99b-mediated TAM phenotype, indicating that TAM-targeted delivery of miR-99b is a potential strategy for cancer immunotherapy. CI - (c) Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY. Published by BMJ. FAU - Wang, Liang AU - Wang L AUID- ORCID: 0000-0003-3068-4004 AD - State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, Fourth Military Medical University, Xi'an, Shaanxi, China. FAU - Hu, Yi-Yang AU - Hu YY AD - State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, Fourth Military Medical University, Xi'an, Shaanxi, China. FAU - Zhao, Jun-Long AU - Zhao JL AD - State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, Fourth Military Medical University, Xi'an, Shaanxi, China. FAU - Huang, Fei AU - Huang F AD - State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, Fourth Military Medical University, Xi'an, Shaanxi, China. FAU - Liang, Shi-Qian AU - Liang SQ AD - State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, Fourth Military Medical University, Xi'an, Shaanxi, China. FAU - Dong, Lei AU - Dong L AD - State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, Jiangsu, China. FAU - Chen, Yan AU - Chen Y AD - Department of Clinical Oncology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China. FAU - Yu, Heng-Chao AU - Yu HC AD - Department of Hepatobiliary Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China. FAU - Bai, Jian AU - Bai J AD - State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, Fourth Military Medical University, Xi'an, Shaanxi, China. FAU - Yang, Jia-Meng AU - Yang JM AD - State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, Fourth Military Medical University, Xi'an, Shaanxi, China. FAU - Fan, Jie-Yi AU - Fan JY AD - State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, Fourth Military Medical University, Xi'an, Shaanxi, China. FAU - Feng, Lei AU - Feng L AD - State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, Fourth Military Medical University, Xi'an, Shaanxi, China. FAU - Li, San-Zhong AU - Li SZ AD - State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, Fourth Military Medical University, Xi'an, Shaanxi, China. FAU - Han, Hua AU - Han H AD - State Key Laboratory of Cancer Biology, Department of Biochemistry and Molecular Biology, Fourth Military Medical University, Xi'an, Shaanxi, China. FAU - Qin, Hong-Yan AU - Qin HY AUID- ORCID: 0000-0003-1038-7037 AD - State Key Laboratory of Cancer Biology, Department of Medical Genetics and Developmental Biology, Fourth Military Medical University, Xi'an, Shaanxi, China hyqin@fmmu.edu.cn. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't PL - England TA - J Immunother Cancer JT - Journal for immunotherapy of cancer JID - 101620585 RN - 0 (MIRN99 microRNA, human) RN - 0 (MicroRNAs) SB - IM MH - Animals MH - Cell Line, Tumor MH - Humans MH - Macrophage Activation/*physiology MH - Mice MH - MicroRNAs/*metabolism MH - Phenotype MH - Transfection PMC - PMC7511616 OTO - NOTNLM OT - antigen presentation OT - immunotherapy OT - liver neoplasms OT - macrophages OT - phagocytosis COIS- Competing interests: None declared. EDAT- 2020/09/20 06:00 MHDA- 2021/10/15 06:00 PMCR- 2020/09/18 CRDT- 2020/09/19 05:29 PHST- 2020/08/12 00:00 [accepted] PHST- 2020/09/19 05:29 [entrez] PHST- 2020/09/20 06:00 [pubmed] PHST- 2021/10/15 06:00 [medline] PHST- 2020/09/18 00:00 [pmc-release] AID - jitc-2019-000517 [pii] AID - 10.1136/jitc-2019-000517 [doi] PST - ppublish SO - J Immunother Cancer. 2020 Sep;8(2):e000517. doi: 10.1136/jitc-2019-000517.