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Abstract Background Liver metastases are a major contributor to the poor immunotherapy response in colorectal cancer patients. However, the distinctions in the immune microenvironment between primary tumors and liver metastases are poorly characterized. The goal of this study was to compare the expression profile of multiple immune cells to further analyze the similarities and differences between the microenvironments of liver metastases and the primary tumor. Methods Tissues from 17 patients with colorectal cancer who underwent resection of primary and liver metastases was analyzed using multispectral immunofluorescence. The expression of multiple immune cells (CD8, Foxp3, CD68, CD163, CD20, CD11c, CD66b, CD56, PD-L1, INF-γ, Ki67 and VEGFR-2) in the tumor center (TC), tumor invasive front (

Chemotherapy is still the main therapeutic strategy for gastric cancer (GC). However, most patients eventually acquire multidrug resistance (MDR). Hyperactivation of the EGFR signaling pathway contributes to MDR by promoting cancer cell proliferation and inhibiting apoptosis. We previously identified the secreted protein CGA as a novel ligand of EGFR and revealed a CGA/EGFR/GATA2 positive feedback circuit that confers MDR in GC. Herein, we outline a microRNA-based treatment approach for MDR reversal that targets both CGA and GATA2. We observed increased expression of CGA and GATA2 and increased activation of EGFR in GC samples. Bioinformatic analysis revealed that miR-107 could simultaneously target CGA and GATA2, and the low expression of miR-107 was correlated with poor prognosis in GC patients. The direct interactions between miR-107 and CGA or GATA2 were validated by luciferase reporter assays and Western blot analysis. Overexpression of miR107 in MDR GC cells increased their susceptibility to chemotherapeutic agents, including fluorouracil, adriamycin, and vincristine, in vitro. Notably, intratumor injection of the miR-107 prodrug enhanced MDR xenograft sensitivity to chemotherapies in vivo. Molecularly, targeting CGA and GATA2 with miR-107 inhibited EGFR downstream signaling, as evidenced by the reduced phosphorylation of ERK and AKT. These results suggest that miR-107 may contribute to the development of a promising therapeutic approach for the treatment of MDR in GC. [ABSTRACT FROM AUTHOR]