5-Aza-2'-deoxycytidine may enhance the frequency of T regulatory cells from CD4+ naïve T cells isolated from the peripheral blood of patients with chronic HBV infection

OBJECTIVES

Methylation pattern of gene modification is essential for the differentiation of T regulatory cells (Tregs) and 5-Aza-2'-deoxycytidine is a common inhibitor of methylation. This study aimed to investigate the potential effects of Treg polarizing conditions and 5-Aza-2'-deoxycytidine treatment in the differentiation of naïve T cells during chronic hepatitis B virus (HBV) infection.

METHODS

The frequency of Tregs in peripheral blood was determined by flow cytometry from patients with chronic hepatitis B (CHB) (n = 51), liver cirrhosis (LC) (n = 47), hepatocellular carcinoma (HCC) (n = 40) and healthy controls (HCs) (n = 17). Gene expression were detected by qRT-PCR and DNA methyltransferases (DNMT) Activity was also determined.

RESULTS

The frequency of Tregs and Foxp3 expression in peripheral blood from 5-Aza-2'-deoxycytidine-treated groups were higher than that with acetic acid treatment as a control. Foxp3 mRNA and the frequency of Tregs derived from naïve CD4⁺T cells from peripheral blood of patients with HCC or LC were more pronounced compared with HCs. 5-Aza-2'-deoxycytidine may have induced a more pronounced upward trend of PD-1 expression in HBV patients.

CONCLUSIONS

5-Aza-2'-deoxycytidine mediated demethylation has potential effects on enhancing the differentiation of naïve T cells to Tregs in chronic HBV infection.

Inhibition of Multiple Myeloma Using 5-Aza-2'-Deoxycytidine and Bortezomib-Loaded Self-Assembling Nanoparticles

Purpose

The aim of this study was to explore the use of self-assembling nanoparticles loaded with two chemotherapy drugs for the treatment of multiple myeloma.

Materials and Methods

Nanoparticle systems were developed based on amine polyethylene glycol-polycaprolactone (NH2-PEG-PCL) to encapsulate 5-Aza-2ʹ-deoxycytidine and Bortezomib using the self-assemble method. Morphological changes were observed by transmission electron microscopy (TEM), and the size, drug release, long-term stability, and release of reactive oxygen species (ROS) were analyzed. The MTT assay was used to evaluate the effects of drug-loaded nanoparticles (PEG-PCL-DAC-BTZ) in inhibiting the proliferation of multiple myeloma cells (U266 and LP-1), and the TUNEL assay and Western blotting were used to measure the induction of cell apoptosis.

Results

Based on the diameter of NH₂-PEG-PCL and PEG-PCL-DAC-BTZ, the drug-loaded nanoparticles were successfully prepared. TEM revealed that PEG-PCL-DAC-BTZ was spherically shaped. More than 90% of the drugs were released after 72 h, and PEG-PCL-DAC-BTZ maintained a good stability. U266 and LP-1 cells treated with PEG-PCL-DAC-BTZ showed the highest growth inhibition, release of ROS, and cell apoptosis compared to those treated with unloaded nanoparticles and chemotherapy drugs alone.

Conclusion

The drug-loaded nanoparticles are a good foundation for the treatment of multiple myeloma as they showed a slow release profile, good stability, and superior anti-cancer effects in vitro.

Treatment with MAPKAP2 (MK2) inhibitor and DNA methylation inhibitor, 5-aza dC, synergistically triggers apoptosis in hepatocellular carcinoma (HCC) via tristetraprolin (TTP)

Over 100 putative driver genes that are associated with multiple recurrently altered pathways were detected in hepatocellular carcinoma (HCC), suggesting that multiple pathways will need to be inhibited for any therapeutic method to be effective. In this context, functional modification of the RNA regulating protein, tristetraprolin (TTP) that regulates approximately 2500 genes represents a promising strategy in HCC therapy. Since overexpression of TTP induces cell death in all cell types, it would be useful to target the regulator of TTP. In this study, we applied an inhibitor to MAPKAP2 (MK2) that suppresses TTP function. Importantly, cBIOportal for HCC genomics shows that expression level of the MK2 gene correlates with clinical outcome of HCC. We show that upon treatment with MK2 inhibitor, all 5 HCC cell lines, namely HepG2, Huh7, Hep3B, HLE and HLF, reduced cell growth, especially HepG2 and Hep3B cells underwent apoptosis. Simultaneously, TTP target genes such as c-Myc, IER3 or AKT-1 were downregulated. Depletion of the TTP gene rescued cells from apoptosis and restored the TTP-target mRNA expression in the presence of MK2 inhibitor. Furthermore, MK2 was activated in primary HCC that express TTP at high level. The TTP gene was induced upon treatment with DNA methylation inhibitor, 5-aza dC or interferon in three other cell lines, Huh7, HLE or HLF. Upon treatment with MK2 inhibitor and 5-aza dC or interferon these cells underwent apoptosis. The depletion of TTP in these cells partially rescued them from apoptosis, suggesting that the MK2/TTP pathway plays a role in proliferation and maintenance of HCCs. Notably, under the same conditions human hepatocyte cells (THLE-2) did not undergo apoptosis. These data also suggest that MK2 inhibitor with 5-aza dC or interferon may be a useful tool for therapy against HCC.