T-cell exhaustion represents a progressive loss of T-cell function. The inhibitory receptor PD-1 is known to negatively regulate CD8+ T cell responses directed against tumor antigen, but the blockades of PD-1 pathway didn't show the objective responses in patients with colorectal cancer (CRC). Thus, further exploring the molecular mechanism responsible for inducing T-cell dysfunction in CRC patients may reveal effective strategies for immune therapy. This study aims to characterize co-inhibitory receptors on T cells in CRC patients to identify novel targets for immunotherapy. In this study, peripheral blood samples from 20 healthy controls and 54 consented CRC patients, and tumor and matched paraneoplastic tissues from 7 patients with advanced CRC, subjected to multicolor flow cytometric analysis of the expression of PD-1 and Tim-3 receptors on CD8+ T cells. It was found that CRC patients presented with significantly higher levels of circulating Tim-3+PD-1+CD8+ T cells compared to the healthy controls (medians of 3.12% and 1.99%, respectively, p = 0.0403). A similar increase of Tim-3+PD-1+CD8+ T cells was also observed in the tumor tissues compared to paraneoplastic tussues. Tim-3+PD-1+CD8+ T cells in tumor tissues produced even less cytokine than that in paraneoplastic tissues. Functional ex vivo experiments showed that Tim-3+PD-1+CD8+ T cells produced significantly less IFN-γ than Tim-3−PD-1−CD8+ T cells, followed by Tim-3+PD-1−CD8+ T cells, and Tim-3−PD-1+CD8+ T cells, indicating a stronger inhibition of IFN-γ production of Tim-3+CD8+ T cells. It is also found in this study that Tim-3+PD-1+CD8+ T cell increase in circulation was correlated with clinical cancer stage but not histologic grade and serum concentrations of cancer biomarker CEA. Our results indicate that upregulation of the inhibitory receptor Tim-3 may restrict T cell responses in CRC patients, and therefore blockage of Tim-3 and thus restoring T cell responses may be a potential therapeutic approach for CRC patients.

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For developing gene therapy for chronic myelogenous leukemia (CML), we evaluated the feasibility of using autologous bone marrow stromal cells (BMSCs) of one CML patient as a target cell population and studied the efficiency of recombinant adenovirus-mediated human Gamma Interferon (hIFN-gamma) gene transfer into BMSCs. BMSCs can be readily obtained, expanded, and successfully transduced with adenoviral vectors in vitro. We studied the in vitro expression of hIFN-gamma in human BMSCs following transduction with Ad/hIFN-gamma. On transduction of BMSCs at a MOI of 50, the expression and secretion of hIFN-gamma were achieved as high as 5492 +/- 660 approximately 50647 +/- 4049 ng/10(6) cells per 24 h over the course of 3 weeks. We further studied the effects of hIFN-gamma produced by transduced BMSCs on the proliferation of the human leukemia cell line K562 cells in vitro, proliferation of K562 cells was markedly inhibited in the experimental groups as compared with the other two control groups after 5 days of coculture. We also found that the percentage of K562 cells in the G(1) phase of cell cycle can be increased by treatment of hIFN-gamma produced by Ad/hIFN-gamma transduced BMSCs, but the percentage of K562 cells in the S phase of cell cycle can be decreased in the same time. Apoptosis rate of K562 cells in the experimental groups was 30.8 +/- 8.5%, as compared with the other two control groups (5.6 +/- 1.3% and 5.5 +/- 0.8%, respectively) (p < 0.01). Our results indicate that hIFN-gamma gene engineered BMSCs of CML donors could be successfully established and that local production of hIFN-gamma is sufficiently to inhibit the proliferation of K562 cells and induce apoptosis of K562 cells in vitro, suggesting an important potential use in the clinical gene therapy of CML.

In summary, our study indicated that high-dose aspirin, rather than low-dose aspirin, might be associated with decreased risk for pancreatic cancer, especially for Americans.

Metaphyseal and epiphyseal trabeculae show regionally specific variations in BMD and microstructure. The former are more susceptible to bone loss induced by estrogen deficiency and would be strengthened by either hypertrophy or hypermineralization, while epiphyseal trabeculae are mainly strengthened by thickening.

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The treatment of a brain glioma remains one of the most difficult challenges in oncology. In the present study a delivery system was developed for targeted drug delivery across the blood-brain barrier (BBB) to the brain cancer cells. A cyclic arginine-glycine-aspartic acid (RGD) peptide and transferrin (TF) were utilized as targeting ligands. Cyclic RGD peptides are specific targeting ligands of cancer cells and TFs are ligands that specifically target the BBB and cancer cells. Liposome (LP) was used to conjugate the cyclic RGD and TFs to establish the brain glioma cascade delivery system (RGD/TF-LP). The LPs were prepared by the thin film hydration method and physicochemical characterization was conducted. In vitro cell uptake and three-dimensional tumor spheroid penetration studies demonstrated that the system could target endothelial and tumor cells, as well as penetrate the tumor cells to reach the core of the tumor spheroids. The results of the in vivo imaging further demonstrated that the RGD/TF-LP provided the highest brain distribution. As a result, the paclitaxel-loaded RGD/TF-LP presents the best antiproliferative activity against C6 cells and tumor spheroids. In conclusion, the RGD/TF-LP may precisely target brain glioma, which may be valuable for glioma imaging and therapy.