Exosomes derived from M1 macrophages inhibit the proliferation of the A549 and H1299 lung cancer cell lines via the miRNA-let-7b-5p-GNG5 axis

Abstract

Background Almost all cells are capable of secreting exosomes (Exos) for intercellular communication and regulation. Therefore, Exos can be used as a natural therapeutic platform to regulate genes or deliver drugs to treat diseases. M1 macrophages inhibit tumor growth by releasing pro-inflammatory factors. This study explored the applicability of M1 macrophage exosomes (M1-Exos) as gene carriers and the effects on GNG5 protein, and further examined whether macrophage repolarization could inhibit tumor activity. Methods M0 macrophages were polarized toward M1 using vitexin. Exos were obtained from M1 macrophages by ultra-centrifugation. The transwell non-contact co-culture system was used to co-culture M1 macrophages with HLF-α human lung epithelial cells or A549 or H1299 lung cancer cells. MTT, scratch, and transwell assays were used to detect the cell viability, migration, and invasion ability of cells in the four groups. Flow cytometry was used to detect the apoptosis rate of each group, and western blot (WB) analysis was performed to detect the change in the expression of proliferation- and apoptosis-related proteins. We screened the differentially expressed microRNAs using quantitative polymerase chain reaction technology. Luciferase reporter analysis was performed to explore the interaction between miRNA and protein. We used Xenografted A549 tumors in nude mice to study the effect of M1-Exos on tumor cell growth in vivo. Results The results showed that, under the M1 macrophage co-culture system, lung cancer cell viability, invasion, and migration ability decreased, and the number of apoptotic cells increased, will all indicators being statistically significant (P < 0.05). The expression levels of PCNA, KI67, and Bcl-2 decreased significantly, but that of Bax increased (P < 0.05). Exosomes can have the same effect on tumor cells as M1 macrophages. Exosomes can transport miR-let-7b-5p to tumor cells, and miR-let-7b-5p can inhibit tumor cell proliferation and promote tumor cell apoptosis by regulating the GNG5 protein level. Conclusions M1-Exos inhibit the proliferation, invasion, and metastasis of lung cancer cells through miRNA-let-7b-5p and GNG5 signaling pathways and inhibit the anti-apoptotic ability of lung cancer cells.

Disruption of LPA‐LPAR1 pathway results in lung tumor growth inhibition by downregulating B7‐H3 expression in fibroblasts

“…The fibroblast cell lines used in our study have been validated in the literature and are extensively employed in various cancer and fibrosis models. [36][37][38][39] There were certain limitations to our study. The unavailability of sufficient Ki16425 prevented us from examining the effect of blocking the LPAR1 signaling pathway on tumor growth in vivo.…”

“…Unfortunately, we were unable to verify these findings using patient‐isolated fibroblasts due to ethical and technical issues. The fibroblast cell lines used in our study have been validated in the literature and are extensively employed in various cancer and fibrosis models 36–39 …”

Exosomal Non-Coding RNAs: Novel Regulators of Macrophage-Linked Intercellular Communication in Lung Cancer and Inflammatory Lung Diseases

“…Compared to M1 macrophage exosomes, miRNA let-7b-5p expression is decreased in M0 macrophage exosomes. Exosomal let-7b-5p from M1 macrophages suppresses cell proliferation and enhances cell apoptosis via repressing the G-protein gamma 5 subunit (GNG5) in A549 and H1299 cells [ 60 ]. As mentioned above, exosomal miRNAs from M2 macrophages always serve as oncogenic factors and promote lung cancer cell proliferation, cell migration, and cell invasion.…”

Exosomes: Diagnostic and Therapeutic Implications in Cancer

“…Tumorigenesis involves interactions among cancer cells, stromal cells, and immune cells [ 11 ]. It is therefore reasonable to expect that exosomes might also mediate these cellular interactions, as has been investigated by prior studies: M2-like macrophage-derived exosomes enhance the metastatic potential of non-small cell lung cancer cells (NSCLCs) through exosomal integrin αVβ3 [ 67 ].…”

“…Exosomes mediate cell-to-cell communication [ 9 , 11 ], and exosomal contents mediate the effects of exosomes on various life processes. Exosomes are involved in angiogenesis [ 12 ], metastasis [ 13 , 14 , 15 ], anticancer drug resistance [ 16 ], immune evasion [ 17 ], macrophage polarization [ 18 ], and metabolic reprogramming [ 19 ].…”