microRNA-21-5p from M2 macrophage-derived extracellular vesicles promotes the differentiation and activity of pancreatic cancer stem cells by mediating KLF3
Authors: Weimin Hu
Hanjun Li
Zhongchao Zhu
Pei Mei
Xingcheng Xiong
Jian Chang
Jing Tao
Journal: Cell Biology and Toxicology (2021)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: Differentiation; Extracellular vesicles; Krüppel-like factor 3; M2 macrophages; MicroRNA-21a-5p
Affiliations: Department of Pancreatic Surgery, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuhan, 430060, Hubei, China., Department of Pancreatic Surgery, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuhan, 430060, Hubei, China. .

Abstract:  Aim: Given the fact that tumor-associated macrophage-derived extracellular vesicles (EVs) are attributable to tumor aggressiveness, this research intends to decode the mechanism of M2 macrophage-derived EVs in the differentiation and activities of pancreatic cancer (PaCa) stem cells via delivering microRNA (miR)-21-5p. Methods: Polarized M2 macrophages were induced, from which EVs were collected and identified. miR-21-5p expression in M2 macrophage-derived EVs was tested. After cell sorting, CD24+CD44+EpCAM+ stem cells were co-cultured with M2 macrophages, in which miR-21-5p was upregulated or downregulated. The effects of M2 macrophage-derived EVs and miR-21-5p on Nanog/octamer-binding transcription factor 4 (Oct4) expression, sphere formation, colony formation, invasion and migration capacities, apoptosis, and in vivo tumorigenic ability were examined. Krüppel-like factor 3 (KLF3) expression and its interaction with miR-21-5p were determined. Results: M2 macrophage-derived EVs promoted PaCa stem cell differentiation and activities. miR-21a-5p was upregulated in M2 macrophage-derived EVs. miR-21a-5p downregulation in M2 macrophage-derived EVs inhibited Nanog/Oct4 expression and impaired sphere-forming, colony-forming, invasion, migration, and anti-apoptosis abilities of PaCa stem cells in vitro and tumorigenic ability in vivo. miR-21-5p targeted KLF3 to mediate the differentiation and activities of PaCa stem cells, and KLF3 was downregulated in PaCa stem cells. Conclusion: This work explains that M2 macrophage-derived exosomal miR-21a-5p stimulates differentiation and activity of PaCa stem cells via targeting KLF3, paving a novel way for attenuating PaCa stemness. 

Retracted: No

PubPeer comments:
 Figs 1f, 6d, 7a. ![file] Is it possible for the authors to upload scans of the original blots for these eyebrow-like Western Blots? They sample the same confined region of morphology space as Figs 1b, 7a of [Yang et al (2021)] ... ![] Figs 1b, 6d f, 7b from [Li et al (2021)] ... ![file] ... and Figs 5b,d and 7b from [Tang Hu (2021)] . ![] A few dozen other examples are [tabulated here] . , 
 This article shares several characteristics with others in the eyebrow family of papers identified by Hoya Camphorifolia. 1. Table 1 is  Primer sequences 2. miRNA RT: No miRNA-specific RT method. Mature miRNA could not have been amplified. 3. miRNA normalizer: GAPDH (?) 4. miRNA-target alignment figure is mis-aligned , 
 Readers should reassess the reliability of this paper as its bibliography includes **several questioned references** that are likely to be unreliable. So far, the following have been spotted: | Questioned Reference Cited | Details | | --- | --- | | [10.1186 s13046-019-1239-3] retracted | 2019 _Journal of Experimental Clinical Cancer Research_: RETRACTED ARTICLE: Down-regulated lncRNA DLX6-AS1 inhibits tumorigenesis through STAT3 signaling pathway by suppressing CADM1 promoter methylation in liver cancer stem cells. Dong-Mei Wu u2022 Zi-Hui Zheng u2022 Ying-Bo Zhang u2022 Shao-Hua Fan u2022 Zi-Feng Zhang u2022 Yong-Jian Wang u2022 Yuan-Lin Zheng u2022 Jun Lu | | [10.1002 jcp.28747] | 2019 _Journal of Cellular Physiology_: microRNAu201016u20105pu2010containing exosomes derived from bone marrowu2010derived mesenchymal stem cells inhibit proliferation, migration, and invasion, while promoting apoptosis of colorectal cancer cells by downregulating ITGA2. Yan Xu u2022 Liangfang Shen u2022 Fujun Li u2022 Junwen Yang u2022 Xiaoping Wan u2022 Miao Ouyang | According to [Dimensions] , this article has been [cited 14 times] . Flagged by the [_Problematic Paper Screener_] , [Feet of Clay] Detector. ,