Novel pH-sensitive nanoformulated docetaxel as a potential therapeutic strategy for the treatment of cholangiocarcinoma.

BACKGROUND: Cholangiocarcinoma (CC) is one of the fatal malignant neoplasms with poor prognosis. The traditional chemotherapy has been resistant to CC and does not improve the quality of life. The aim of the present study is to investigate the potential of chondroitin sulphate (CS)-histamine (HS) block copolymer micelles to improve the chemotherapeutic efficacy of docetaxel (DTX). RESULTS: pH-responsive property of CS-HS micelles was utilized to achieve maximum therapeutic efficacy in CC. In the present study, docetaxel-loaded CS-HS micelles (CSH-DTX) controlled the release of drug in the basic pH while rapidly released its cargo in the tumor pH (pH 5 and 6.8) possibly due to the breakdown of polymeric micelles. A nanosize of <150 nm will allow its accumulation in the tumor interstitial spaces via EPR effect. CSH-DTX effectively killed the cancer kills in a time- and concentration-dependent manner and showed pronounced therapeutic action than that of free drug at all-time points. CSH-DTX resulted in higher apoptosis of cancer cells with ~30% and ~50 of cells in early apoptosis quadrant when treated with 100 and 1000 ng/ml of equivalent drug. The micellar formulations showed remarkable effect in controlling the tumor growth and reduced the overall tumor volume to 1/5(th) to that of control and half to that of free drug treated group with no sign of drug-related adverse effects. Immunohistochemical analysis of tumor sections showed that fewer number of Ki-67 cells were present in CSH-DTX treated group comparing to that of free DTX treated group. CONCLUSION: Our data suggests that nanoformulation of DTX could potentially improve the chemotherapy treatment in cholangiocarcinoma as well as in other malignancies.

[Histone deacetylase inhibitor MS-275 treatment alters immune molecule content and categories in hepatocarcinoma exosomes].

OBJECTIVE: To investigate the effects of the histone deacetylase inhibitor, MS-275, on the immune molecule content and categories in hepatocarcinoma exosomes. METHODS: Exosomes were isolated from the human hepatocarcinoma cell lines, HepG2 and Hep3b, and purified by a combination technique of ultrafiltration centrifugation and sucrose gradient ultracentrifugation. The expressions of heat shock protein (HSP)70, human leukocyte antigen (HLA)-I, HLA-DR, cluster of differentiation (CD) 80 and NY-ESO-1 on exosomes were analyzed with immunoelectron microscopy and Western blotting before and after MS-275 treatment. Intergroup differences were statistically analyzed by the Student's paired t-test. RESULTS: MS-275 treatment of both HepG2 and Hep3b cell types significantly increased the numbers of exosomes, their total protein content, and expression of HSP70, HLA-I and CD80 (per 100 exosomes), as compared to non-treated cells (all, P less than 0.01). MS-275 was also found to induce de novo expression of HLA-DR, but had no significant effect on NY-ESO-1 expression (P more than 0.05). The findings from immunoelectron microscopy confirmed those from Western blotting. CONCLUSION: The histone deacetylase inhibitor, MS-275, can significantly alter the immune molecule content and categories in exosomes of hepatocarcinoma cells. The differential expression profile may reflect an anti-cancer immune response and represent molecular targets for novel anti-hepatoma therapeutic or preventative strategies.

Effect of 5-aza-2'-deoxycytidine on immune-associated proteins in exosomes from hepatoma.

AIM: To study the effect of 5-aza-2'-deoxycytidine (5-aza-CdR) on heat shock protein 70 (HSP70), human leucocyte antigen-I (HLA-I) and NY-ESO-1 proteins in exosomes produced by hepatoma cells, HepG2 and Hep3B. METHODS: Exosomes derived from HepG(2) and Hep3B cells treated with or without 5-aza-CdR were isolated and purified by ultrafiltration centrifugation and sucrose gradient ultracentrifugation. The number of exosomes was counted under electron microscope. Concentration of proteins in exosomes was measured by bicinchoninic acid protein assay. Expression of HSP70, HLA-I and NY-ESO-1 proteins in exosomes was detected by Western blotting and immunoelectron microscopy. mRNA expression of p53 gene was detected by reverse transcription polymerase chain reaction. RESULTS: The mRNA expression of p53 gene was increased in both hepatoma cell lines after treatment with 5-aza-CdR. The number of exosomes and the concentration of total proteins in exosomes were increased significantly after treatment with 5-aza-CdR (P < 0.05). After treatment with 5-aza-CdR, immunoelectron microscopy and Western blotting showed that the HSP70, HLA-I and NY-ESO-1 proteins were increased in exosomes produced by both hepatoma cell lines. CONCLUSION: 5-Aza-CdR, an inhibitor of DNA methyltransferase, can increase exosomes produced by hepatoma cells and immune-associated protein component of exosomes, which may be mediated by p53 gene up-regulation and 5-aza-CdR demethylation.