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Cytosolic co-delivery of miRNA-34a and docetaxel with core-shell nanocarriers via caveolae-mediated pathway for the treatment of metastatic breast cancer

View Article: PubMed Central - PubMed

ABSTRACT

-: Codelivery of microRNAs and chemotherapeutic drugs into tumor cells is an attractive strategy for synergetic breast cancer therapy due to their complementary mechanisms. In this work, a core-shell nanocarrier coated by cationic albumin was developed to simultaneously deliver miRNA-34a and docetaxel (DTX) into breast cancer cells for improved therapeutic effect. The co-delivery nanocarriers showed a spherical morphology with an average particle size of 183.9 nm, and they efficiently protected miRNA-34a from degradation by RNase and serum. Importantly, the nanocarriers entered the cytosol via a caveolae-mediated pathway without entrapment in endosomes/lysosomes, thus improving the utilization of the cargo. In vitro, the co-delivery nanocarriers suppressed the expression of anti-apoptosis gene Bcl-2 at both transcription and protein levels, inhibited tumor cell migration and efficiently induced cell apoptosis and cytotoxicity. In vivo, the co-delivery nanocarriers prolonged the blood circulation of DTX, enhanced tumor accumulation of the cargo and significantly inhibited tumor growth and metastasis in 4T1-tumor bearing mice models. Taken together, the present nanocarrier co-loading with DTX and miRNA-34a is a new nanoplatform for the combination of insoluble drugs and gene/protein drugs and provides a promising strategy for the treatment of metastatic breast cancer.

No MeSH data available.


Cellular uptake of CNCs observed by CLSM (a,b) and measured by FCM (c,d). Dual fluorescence-labeled CNCs were prepared by loading C6 (green) in the cores and Cy5-RNA (red) in the shells of CNCs. A549 cells (a,c) or 4T1 cells (b,d) were incubated with CNCs for 4 h at 37 °C. Cell nuclei (blue) were stained with DAPI. Free dye (C6 or Cy5-RNA) was used as control. Scale bar: 10 μm.
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f3: Cellular uptake of CNCs observed by CLSM (a,b) and measured by FCM (c,d). Dual fluorescence-labeled CNCs were prepared by loading C6 (green) in the cores and Cy5-RNA (red) in the shells of CNCs. A549 cells (a,c) or 4T1 cells (b,d) were incubated with CNCs for 4 h at 37 °C. Cell nuclei (blue) were stained with DAPI. Free dye (C6 or Cy5-RNA) was used as control. Scale bar: 10 μm.

Mentions: To detect by CLSM and flow cytometry (FCM), fluorescence probes, C6 (green) was loaded in the core and Cy5-labeled miRNA-34a (Cy5-RNA, red) was incorporated in the shell of CNCs simultaneously. To evaluate the stability of C6 and Cy5-RNA in CNCs, the in vitro leakage of C6 and Cy5-RNA from CNCs in serum-free medium were performed. As shown in Supplementary Fig. S5, less than 3% of C6 or Cy5-RNA were released from CNCs at 6 h, thereby indicating that the fluorescence-labeled CNCs were stable during use. As shown in Fig. 3a and b, after 4 h incubation with free C6 and Cy5-RNA, little fluorescent signals were present in A549 or 4T1 cells, indicating that free C6 or Cy5-RNA could hardly be internalized by cells. In contrast, significant fluorescent signals of C6 (green in the web version) and Cy5-RNA (red in the web version) were present in the cytoplasm of A549 or 4T1 cells upon treated with dual fluorescence-labeled CNCs; moreover, obvious yellow fluorescent spots in the cytoplasm after overlapping of green and red fluorescence could be seen in the merged images. FCM analysis further demonstrated that almost 100% of 4T1 or A549 cells were both C6-positive and Cy5-positive (Fig. 3c and d). These results suggested that CNCs could be efficiently taken by 4T1 or A549 cells and were able to deliver drugs and miRNAs into the same tumor cells simultaneously.


Cytosolic co-delivery of miRNA-34a and docetaxel with core-shell nanocarriers via caveolae-mediated pathway for the treatment of metastatic breast cancer
Cellular uptake of CNCs observed by CLSM (a,b) and measured by FCM (c,d). Dual fluorescence-labeled CNCs were prepared by loading C6 (green) in the cores and Cy5-RNA (red) in the shells of CNCs. A549 cells (a,c) or 4T1 cells (b,d) were incubated with CNCs for 4 h at 37 °C. Cell nuclei (blue) were stained with DAPI. Free dye (C6 or Cy5-RNA) was used as control. Scale bar: 10 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5382875&req=5

f3: Cellular uptake of CNCs observed by CLSM (a,b) and measured by FCM (c,d). Dual fluorescence-labeled CNCs were prepared by loading C6 (green) in the cores and Cy5-RNA (red) in the shells of CNCs. A549 cells (a,c) or 4T1 cells (b,d) were incubated with CNCs for 4 h at 37 °C. Cell nuclei (blue) were stained with DAPI. Free dye (C6 or Cy5-RNA) was used as control. Scale bar: 10 μm.
Mentions: To detect by CLSM and flow cytometry (FCM), fluorescence probes, C6 (green) was loaded in the core and Cy5-labeled miRNA-34a (Cy5-RNA, red) was incorporated in the shell of CNCs simultaneously. To evaluate the stability of C6 and Cy5-RNA in CNCs, the in vitro leakage of C6 and Cy5-RNA from CNCs in serum-free medium were performed. As shown in Supplementary Fig. S5, less than 3% of C6 or Cy5-RNA were released from CNCs at 6 h, thereby indicating that the fluorescence-labeled CNCs were stable during use. As shown in Fig. 3a and b, after 4 h incubation with free C6 and Cy5-RNA, little fluorescent signals were present in A549 or 4T1 cells, indicating that free C6 or Cy5-RNA could hardly be internalized by cells. In contrast, significant fluorescent signals of C6 (green in the web version) and Cy5-RNA (red in the web version) were present in the cytoplasm of A549 or 4T1 cells upon treated with dual fluorescence-labeled CNCs; moreover, obvious yellow fluorescent spots in the cytoplasm after overlapping of green and red fluorescence could be seen in the merged images. FCM analysis further demonstrated that almost 100% of 4T1 or A549 cells were both C6-positive and Cy5-positive (Fig. 3c and d). These results suggested that CNCs could be efficiently taken by 4T1 or A549 cells and were able to deliver drugs and miRNAs into the same tumor cells simultaneously.

View Article: PubMed Central - PubMed

ABSTRACT

-: Codelivery of microRNAs and chemotherapeutic drugs into tumor cells is an attractive strategy for synergetic breast cancer therapy due to their complementary mechanisms. In this work, a core-shell nanocarrier coated by cationic albumin was developed to simultaneously deliver miRNA-34a and docetaxel (DTX) into breast cancer cells for improved therapeutic effect. The co-delivery nanocarriers showed a spherical morphology with an average particle size of 183.9 nm, and they efficiently protected miRNA-34a from degradation by RNase and serum. Importantly, the nanocarriers entered the cytosol via a caveolae-mediated pathway without entrapment in endosomes/lysosomes, thus improving the utilization of the cargo. In vitro, the co-delivery nanocarriers suppressed the expression of anti-apoptosis gene Bcl-2 at both transcription and protein levels, inhibited tumor cell migration and efficiently induced cell apoptosis and cytotoxicity. In vivo, the co-delivery nanocarriers prolonged the blood circulation of DTX, enhanced tumor accumulation of the cargo and significantly inhibited tumor growth and metastasis in 4T1-tumor bearing mice models. Taken together, the present nanocarrier co-loading with DTX and miRNA-34a is a new nanoplatform for the combination of insoluble drugs and gene/protein drugs and provides a promising strategy for the treatment of metastatic breast cancer.

No MeSH data available.