ABSTRACT
M2 macrophages serve roles in inhibiting inflammation and promoting tumor development. Reversing tumor-associated macrophages (TAMs) from M2- to M1-type polarization may provide an important strategy for tumor immunotherapy. The present study aimed to enhance antitumor immunity by targeting the concentration of iron in macrophages. Fe3O4-based poly(lactic-co-glycolic) acid (PLGA) nanoparticles surface-modified with an anti-CD206 monoclonal antibody were prepared using the oil in water single-emulsion technique. Particle size was measured using a particle size analyzer, the ζ potential was determined using a ζ potential analyzer and the carrier rate of Fe3O4 was measured using an iron assay kit. The conjugation of anti-CD206, and the ability to target M2 macrophages were studied via immunofluorescence. Polarization indexes of the macrophages were detected using both western blotting and reverse transcription-quantitative PCR (RT-qPCR), and a mouse model with subcutaneous tumors was established to verify the antitumor effects of the nanoparticles in vivo. Nanoparticles had a mean diameter in the range of 260-295 nm, and the ζ potential values were between -19 and -33 mV. The Fe3O4 association efficiency ranged from 65-75%, whereas the anti-CD206 conjunction efficiency ranged from 65-70%. The immunofluorescence experiments were able to demonstrate the successful targeting of the M2 macrophages. The western blotting and RT-qPCR experiments identified that CD206-Fe3O4-PLGA and Fe3O4-PLGA promoted the expression of TNF-α, inducible nitric oxide synthase (iNOS) and IL-1ß in the macrophages. The in vivo studies indicated that CD206-Fe3O4-PLGA nanoparticles were able to promote CD86 expression in TAMs, with CD86 being a specific marker of the M1 subtype. In summary, nanoparticles were characterized in the present study by their mean particle size, polydispersity index, ζ potential and morphology, as well as by their association with Fe3O4 and conjugation with the anti-CD206 monoclonal antibody. Collectively, the present results suggested that the nanoparticles were able to both target M2 macrophages and reverse the M2 polarization of the macrophages to the M1 phenotype via the release of coated iron-oxide particles.
ABSTRACT
OBJECTIVE: To detect the expression of RhoC and Rho kinase 1 (ROCK-1) in prostate carcinoma, and explore the possible mechanism of RhoC/ROCK-1 in the pathogenesis of prostate carcinoma. METHODS: Tissue specimens from 73 patients with prostate carcinoma and corresponding paracancerous tissues were obtained by prostate cancer biopsy or radical prostatectomy. The expression of RhoC/ROCK-1 mRNA was detected by RT-PCR. Western blot and immunohistochemistry were performed to dertect the expression of RhoC/ROCK-1 protein. Eukaryotic expression plasmids of RhoC were constructed and transfected into PC-3M-2B4 cells. p-MAPK and p-Akt were detected by Western bolt. RESULTS: The expression levels of RhoC and ROCK-1 mRNA in the prostate carcinomas were significantly higher than those in corresponding paracancerous tissues [72.6% (53/73) vs. 34.2% (25/73); 68.5% (50/73) vs. 38.4% (28/73), P < 0.01], respectively. The results indicated that RhoC/ROCK-1 mRNA expression had no significant correlation with Gleason grade. However, the expression of RhoC/ROCK-1 mRNA showed a significant positive correlation with distant metastasis. The RhoC/ROCK-1 protein expression in prostate cancer was also higher than corresponding paracancerous tissues, and showed a significant positive correlation with p-MAPK and p-Akt expression levels. In addition, p-MAPK and p-Akt expression levels were up-regulated in the transcripts. CONCLUSION: Expression levels of RhoC and ROCK-1 in prostate carcinoma are higher than those in corresponding paracancerous tissues, showing a significant positive correlation with distant metastasis. RhoC/ROCK-1 may be involved in the development, invasion and metastasis of prostate carcinoma.
