RESUMO
Objective : To study the synergistic effect of chemo-photothermal on castration-resistant prostate cancer (CRPC) for enhancing the efficacy of chemotherapy by single-walled carbon nanotubes (SWCNTs). Methods ¡¤ High-purity SWCNTs were used as the drug carrier. Firstly, SWCHTs were truncated (shorten SWCNTs, s-SWCNTs) by mixed acid solutions. At the same time, a large amount of -COOH were in-troduced onto the surface of s-SWCNTs. Secondly, the polyethylene glycol (PEG) with amino terminated was successfully modified onto s-SWCNTs through amido linkage in N-hydroxysuccinimide and 1-(3-dimethylaminopropyl)-3-ethyl-carbodiimide hydrochloride solutions to endow s-SWCNTs with water solubility and biocompatibility. Finally, docetaxel (DTX) was successfully loaded through nano-deposition method and π-π stacking on the surface of s-SWCNTs. Thus a nanosystem with both chemotherapy and photothermal properties was established. The chemo-photothermal therapy synergistic inhibition on CRPC cell line C4-2 in vitro and the anti-tumor effect in vivo were evaluated. Results ¡¤ Fourier transform infrared spectrum and zeta potential test showed that -COOH was successfully introduced onto s-SWCNTs, and the amount of -COOH was 0.412 mol per gram of SWCNTs determined by automatic conduct metric titration. The UV absorption spectrum showed that DTX was successfully loaded onto the nanosystem. By monitoring the UV absorption of the dialysate, DTX could be loaded onto SWCNTs up to 1.35 mg per gram of s-SWCNTs. Under the stimulation of acidic conditions, DTX could be rapidly released from the surface of the nanosystem. The in vitro cell viability and in vivo anti-tumor experiment showed that DTX combined with photothermal had a synergetic effect on killing C4-2 cells than any single treatment model. Conclusion ¡¤ DTX-loaded s-SWCNTs nanosystem with high stability and photothermal effect can inhib-it the growth of CRPC cells and the tumor growth in mice bearing CRPC. The nanosystem with synergistic effect of chemotherapy and photo-thermal therapy could be used in the treatment of prostate cancer which is resistant to chemotherapy drugs.
RESUMO
<p><b>Objective</b>To study the correlation of high-risk human papillomavirus 16 and 18 (HPV16/18) infections with the risk of prostate cancer (PCa) and their association with the clinicopathologic indexes of PCa.</p><p><b>METHODS</b>We collected tissue samples from 75 cases of PCa and 73 cases of benign prostatic hyperplasia (BPH). We detected HPV16/18 infections in the samples by immunohistochemistry and PCR combined with reverse dot blot (RDB) assay.</p><p><b>RESULTS</b>Immunohistochemistry revealed 16 cases of HPV16/18 positive in the PCa (21.3%) and 7 cases in the BPH samples (9.5%), with statistically significant difference between the two groups (P=0.049). PCR combined with RDB assay showed 17 cases of HPV16 infection (22.6%) and 13 cases of HPV18 infection (17.8%), including 4 cases of HPV16/18 positive, in the PCa group, remarkably higher than 6 cases of HPV16 infection (8.2%), 3 cases of HPV18 infection (4.1%) and no HPV16/18 positive in the BPH controls (P=0.001). No significant differences were observed between the result of immunohistochemistry and that of PCR combined with RDB assay (P=0.069). The risk of HPV16/18 infections was found to be correlated with the clinical T-stage and Gleason score of PCa (P<0.05 ) but not with the patient's age, PSA level or lymph node metastasis (P>0.05 ).</p><p><b>CONCLUSIONS</b>High-risk HPV16/18 infections are correlated with the risk of prostate cancer.</p>