Tumor-associated macrophage-derived exosomal miR-513b-5p is a target of jianpi yangzheng decoction for inhibiting gastric cancer

Abstract

Ethnopharmacological relevance: Jianpi Yangzheng decoction (JPYZ) possesses a potential anti-tumor activity in gastric cancer. However, potential effect of JPYZ on regulating tumor-associated macrophage (TAM)-derived exosomes to affect gastric cancer is still unclear.

Aim of study: We aimed to clarify the role of tumor-associated macrophage derived exosomes (TAM-exos) in invasive and metastasis of gastric cancer and the mechanism of JPYZ regulate TAM-exos against gastric cancer.

Materials and methods: Flow cytometry was performed to demonstrate whether JPYZ involved in TAM polarization. After JPYZ treatment, TAM conditioned medium (TAM-CM)/TAM-exos were co-cultured with gastric cancer cells and were detected by wound healing and transwell assay. Transcriptome sequencing and bioinformatics analysis predicted the exosomal miRNA after JPYZ intervention in TAM. miRNA mimic and inhibitor were used to verify the effect of miRNA in exosomes on gastric cancer cells. Q-PCR and luciferase reporter assay were employed to clarify the targeting relationship between miRNA and target gene. Western blot assay detected the expression levels of epithelial-mesenchymal transition (EMT) markers and related signaling pathways proteins.

Results: We firstly demonstrated that TAM-CM intervened by JPYZ significantly inhibited the invasion and migration of gastric cancer. Furthermore, exosomes in TAM supernatants play a key role in migration of gastric cancer. Meanwhile, transcriptome sequencing and q-PCR revealed that miR-513b-5p expression was significantly reduced in TAM-exos intervened by JPYZ. And miR-513b-5p in TAM aggravated TAM-exos mediated invasion and migration of gastric cancer cells, the inhibitor of miR-513b-5p reversed TAM-exos mediated promotion. Bioinformatics analysis and luciferase reporter assay confirmed that PTEN was a direct target of miR-513b-5p in gastric cancer. MiR-513b-5p inhibited PTEN to activate AKT/mTOR signaling pathway thus promoting gastric cancer invasion and metastasis in vivo and in vitro. Importantly, JPYZ inhibited TAM derived exosomal miR-513b-5p, and alleviated AKT/mTOR activation by PTEN depended manner in gastric cancer.

Conclusion: TAM-exos containing miR-513b-5p lead to gastric cancer invasion and migration. Our findings clarify a novel TAM-exos mechanism of JPYZ for inhibiting gastric cancer progression.

Keywords: Gastric cancer; TAM-Exos; Traditional Chinese medicine; miRNA.