Grapefruit-derived nanovectors deliver miR-18a for treatment of liver metastasis of colon cancer by induction of M1 macrophages

Feng

Molecular Medicine Reports

et al. 2017

Dysregulation of microRNAs (miRNAs) in colorectal cancer provides important opportunities for the development of future miRNA‑based therapies. The present study aimed to assess the role of miRNA‑630 (miR‑630) expression in colorectal cancer. HCT116 human colorectal cancer cells were transfected with miR‑630 inhibitor, mimic or control miRNA, and the effects of miR‑630 dysregulation on cell viability, proliferation and apoptosis were analyzed using MTT and bromodeoxyuridine assays, and an annexin V‑fluorescein isothiocyanate cell apoptosis kit, respectively. In addition, the changes in the protein expression of proliferation‑associated and AKT signaling pathway proteins were analyzed by western blot analysis. The results of the present study demonstrated that overexpression of miR‑630 significantly promoted HCT116 cell proliferation however inhibited apoptosis. Furthermore, miR‑630 overexpression reduced the protein expression of p27, BCL2‑associated X apoptosis regulator, procaspase‑3 and active caspase‑3, and increased the levels of phosphorylated‑AKT and BCL2 apoptosis regulator. The suppression of miR‑630 led to the opposite results. In conclusion, the present findings suggested that miR‑630 may function as an oncogenic miRNA in colorectal cancer, and may promote cellular proliferation and inhibit apoptosis, through the regulation of the expression of p27 and the AKT signaling pathway. The present study suggested that the inhibition of miR‑630 may have potential as an alternative therapeutic strategy for the treatment of patients with colorectal cancer.

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

microRNA-630 promotes cell proliferation and inhibits apoptosis in the HCT116 human colorectal cancer cell line

Feng

Molecular Medicine Reports

et al. 2017

“…Free GNVs and GNVs loaded with Dox (GNV-Dox), Dox+LA1 (GNV-Dox-LA1), and Dox+LA1+Psi (GNVDox-Psi-LA1) were prepared as previously reported [16]. Pre-prepared GNV-Dox was incubated with PEI for 60 min at room temperature; after centrifugation at 36, 000 rpm for 1 h, PEI-modified GNV-Dox (GNV-Dox-PEI) were resuspended and incubated overnight at 4°C with LA1 without or with Psi.…”

Section: Preparation and Characterization Of Dox La1 And Psi-loadedmentioning

confidence: 99%

Overcoming Drug Resistance in Colon Cancer by Aptamer-Mediated Targeted Co-Delivery of Drug and siRNA Using Grapefruit-Derived Nanovectors

Yan

Tao

Jiang

et al. 2018

Cell Physiol Biochem

Background/Aims: Multidrug resistance (MDR) is the most common cause of chemotherapy failure. Upregulation of P-glycoprotein (P-gp) is one of the main mechanisms underlying MDR. Methods: In this study, we developed a targeted drug and small interfering (si)RNA co-delivery system based on specific aptamer-conjugated grapefruit-derived nanovectors (GNVs) that we tested in MDR LoVo colon cancer cells. The internalization of nanovectors in cancer cells was tested by fluorescence microscopy and flow cytometry. The anti-cancer activity in vitro was determined by colony formation and cell apoptosis assays. The biodistribution of nanovectors was analyzed by live imaging and the anti-cancer activity in vivo was observed. Results: GNVs loaded with aptamer increased doxorubicin (Dox) accumulation in MDR LoVo cells, an effect that was abolished by pretreatment with DNase. The LA1 aptamer effectively promoted nanovector internalization into cells at 4°C and increased the targeted delivery of Dox to tumors. Constructs harboring Dox, LA1, and P-gp siRNA more effectively inhibited proliferation and enhanced apoptosis in cultured MDR LoVo cells while exhibiting more potent anti-tumor activity in vivo than free Dox or GNVs loaded with Dox alone or in conjunction with LA1, an effect that was associated with downregulation of P-gp expression. Conclusion: This GNV-based system may be an effective strategy for overcoming MDR in clinical settings.

“…Kupffer cells are the resident macrophages of the liver and contribute to the metastatic process. (25,26) To elucidate the role of hepatic macrophages in liver metastasis, we determined the numbers of hepatic macrophages by immunofluorescence analysis. As shown in Figure 3(a), F4/80 + cells markedly accumulated into the metastatic tumors in WT compared with AT1aKO.…”

Section: Resultsmentioning

confidence: 99%

Angiotensin II subtype 1a receptor signaling in resident hepatic macrophages induces liver metastasis formation

et al. 2017

Liver metastases from colorectal cancer (CRC) are a clinically significant problem. The renin–angiotensin system is involved in tumor growth and metastases. This study was designed to evaluate the role of angiotensin II subtype receptor 1a (AT1a) in the formation of liver metastasis in CRC. A model of liver metastasis was developed by intrasplenic injection of mouse colon cancer (CMT‐93) into AT1a knockout mice (AT1aKO) and wild‐type (C57BL/6) mice (WT). Compared with WT mice, the liver weight and liver metastatic rate were significantly lower in AT1aKO. The mRNA levels of CD31, transforming growth factor‐ β1 (TGF‐β1), and F4/80 were suppressed in AT1aKO compared with WT. Double immunofluorescence analysis showed that the number of accumulated F4/80+ cells expressing TGF‐β1 in metastatic areas was higher in WT than in AT1aKO. The AT1aKO bone marrow (BM) (AT1aKO‐BM)→WT showed suppressed formation of liver metastasis compared with WT‐BM→WT. However, the formation of metastasis was further suppressed in WT‐BM→AT1aKO compared with AT1aKO‐BM→WT. In addition, accumulated F4/80+ cells in the liver metastasis were not BM‐derived F4/80+ cells, but mainly resident hepatic F4/80+ cells, and these resident hepatic F4/80+ cells were positive for TGF‐β1. Angiotensin II enhanced TGF‐β1 expression in Kupffer cells. Treatment of WT with clodronate liposomes suppressed liver metastasis by diminishing TGF‐β1+F4/80+ cells accumulation. The formation of liver metastasis correlated with collagen deposition in the metastatic area, which was dependent on AT1a signaling. These results suggested that resident hepatic macrophages induced liver metastasis formation by induction of TGF‐β1 through AT1a signaling.