Progress in cancer vaccines by enhanced self-presentation

Tumor Microenvironment-Responsive Polypeptide Nanogels for Controlled Antitumor Drug Delivery

Tumor microenvironment-responsive polypeptide nanogels belong to a biomaterial with excellent biocompatibility, easily adjustable performance, biodegradability, and non-toxic properties. They are developed for selective delivery of antitumor drugs into target organs to promote tumor cell uptake, which has become an effective measure of tumor treatment. Endogenous (such as reduction, reactive oxygen species, pH, and enzyme) and exogenous (such as light and temperature) responsive nanogels can release drugs in response to tumor tissues or cells to improve drug distribution and reduce drug side effects. This article systematically introduces the research progress in tumor microenvironment-responsive polypeptide nanogels to deliver antitumor drugs and provides a reference for the development of antitumor nanoformulations.

Selected Office Based Anticancer Treatment Strategies

Over the years, the treatment of patients with cancer has varied widely as much because of recent advancements in science and medicine as the philosophies that belie their use. This paper briefly describes many of the prevailing approaches in use today with an attempt to offer some perspective of how to apply these disparate methodologies so that they may be more effectively integrated, resulting in consistently better clinical responses.

Cord blood stem-cell-derived dendritic cells generate potent antigen-specific immune responses and anti-tumour effects

The aim of the present study was to investigate whether CBSCs [(umbilical) cord blood stem cells] can be a new source of DCs (dendritic cells), which can generate more potent antigen-specific immune responses and anti-tumour effects. CBSCs and PBMCs (peripheral blood mononuclear cells) were collected, cultured and differentiated into DCs. Surface markers, secreting cytokines, antigen-presentation activity, antigen-specific cell-mediated immunity and cytotoxic killing effects induced by these two DC origins were evaluated and compared. CBSCs were expanded ~17-fold by ex vivo culture. The expression of surface markers in CBSC-derived DCs were higher than those in PBMC-derived DCs treated with LPS (lipopolysaccharide). The CBSC-derived DCs mainly secreted IL (interleukin)-6, IL-10 and TNF (tumour necrosis factor)-α, whereas PBMC-derived DCs mainly secreted IL-5 and IFN (interferon)-γ. The CBSC-derived DCs had better antigen-presentation abilities when stimulated with LPS or TNF-α, induced higher numbers of IFN-γ-secreting antigen-specific CD8+ T-cells, as assessed using an ELISpot (enzyme-linked immunosorbent spot) assay, and stimulated more potent antigen-specific CTL (cytotoxic T-cell) activities (P<0.01, one-way ANOVA). CBSC-derived DCs had quicker and greater ERK (extracellular-signal-regulated kinase) and Akt phosphorylation, and weaker p38 phosphorylation, than PBMC-derived DCs when stimulated with LPS. In conclusion, CBSC-derived DCs have the ability to induce stronger antigen-specific immunity and more potent anti-tumour effects and therefore could be a good source of DCs for use in DC-based cancer vaccines and immunotherapy.

Antitumor activity of a fusion of esophageal carcinoma cells with dendritic cells derived from cord blood

The aim of this experiment was to develop a cytotoxic cancer vaccine (EC109-DC) prepared by fusions of esophageal carcinoma cells with dendritic cells derived from cord blood and to study the biological characteristics and resultant induction of antitumor immunity. CD34+ hematopoietic stem cells were isolated from cord blood using a CD34+ Progenitor Cell Isolation Kit by magnetic cell sorting system (MACS). CD34+ cells were incubated with rhGM-CSF, rhTNF-alpha and rhSCF for 2 weeks as DC (dendritic cells), and then by PEG-3600 to fuse with an esophageal carcinoma cell line. Selection with MACS marked with HLA-DR MicroBeads generated EC109-DC. Phenotypes and proliferation were analyzed by flow cytometry and cell culture in vitro. The lymphocyte proliferation reaction and CTL cytotoxicity were examined by MTT assay. The EC109-DC cells could proliferate slowly in vitro and highly expressed CD80, CD83 and CD86. The lymphocyte proliferation reaction and specific cytotoxicity against EC109 induced by EC109-DC cells were significantly higher than in control groups (p < 0.05). EC109-DC cells obtained by PEG fusion acquired the immuno-stimulating phenotype and could significantly stimulate the lymphocyte proliferation reaction and CTL activity. The results of this research provide the basis for materials to develop the DC-based vaccine against esophageal carcinoma.

Progress in the Development of Immunotherapy of Cancer Using Ex Vivo-Generated Dendritic Cells Expressing Multiple Tumor Antigen Epitopes

Immunotherapy with tumor-associated antigen-pulsed, ex vivo-generated dendritic cells (DCs) is a promising approach for the treatment of cancer that has shown efficacy in animal models and is now being tested in the clinic. The majority of studies performed to date make use of a single tumor-associated epitope. However, because of the high rate of mutation in tumor cells allowing for loss of expression of a single antigen, it is likely that use of multiple antigenic epitopes will induce a broader, longer-lasting, and effective tumor-specific immune response. Multiple vehicles for loading DCs with multiple antigenic epitopes are under investigation to determine the most effective method for vaccination, with many of these methods showing promise. These loading methods, as well as other critical considerations for making DC vaccination as efficacious as possible, are discussed in this article.