Diffuse intrinsic pontine glioma (DIPG) is a deadly paediatric brain cancer. Transient response to radiation, ineffective chemotherapeutic agents and aggressive biology result in rapid progression of symptoms and a dismal prognosis. Increased availability of tumour tissue has enabled the identification of histone gene aberrations, genetic driver mutations and methylation changes, which have resulted in molecular and phenotypic subgrouping. However, many of the underlying mechanisms of DIPG oncogenesis remain unexplained. It is hoped that more representative in vitro and preclinical models–using both xenografted material and genetically engineered mice–will enable the development of novel chemotherapeutic agents and strategies for targeted drug delivery. This review provides a clinical overview of DIPG, the barriers to progress in developing effective treatment, updates on drug development and preclinical models, and an introduction to new technologies aimed at enhancing drug delivery.
Biology ; Brain Neoplasms ; Brain Stem Neoplasms ; Carcinogenesis ; Glioma ; Heterografts ; Histones ; Hope ; In Vitro Techniques ; Methylation ; Molecular Biology ; Prognosis

The infusion and persistence in a transplant recipient of donor-derived bone marrow cells (DBMC) of multi-lineage can lead to a state of permanent chimerism. In solid vascular organ transplantation, the donor bone marrow lineage cells can even be derived from the transplant organ, and these cells can be detected in very small numbers in the recipient. This has been called microchimerism. Much controversy has developed with respect to the function of chimeric cells in organ transplantation. One idea is that the occurrence of these donor cells found in microchimerism in the recipient are coincidental and have no long-term beneficial effect on engraftment. A second and opposing view, is that these donor cells have immunoregulatory function that affect both the acute and chronic phases of the recipient anti-donor responses. It follows that detecting quantitative changes in chimerism might serve as an indication of the donor-specific alloimmune or regulatory response that could occur in concert with or independent of other adaptive immune responses. The latter, including autoimmune native disease, need to be controlled in the transplant organ. The safety and immune tolerance potential of DBMC infusion with deceased and living donor renal transplants was evaluated in a non-randomized trial at this center and compared with non-infused controls given identical immunosuppression. Overall DBMC infusions were well tolerated by the recipients. There were no complications from the infusion (s), no episodes of graft-vs-host disease (GVHD) and no increase infections or other complications. In the deceased DBMC- kidney trial, actuarial graft survival at 5 years was superior especially when graft survival was censored for recipient death. Acute rejections were significant reduced in patients given two DBMC infusions, and chronic rejection was dramatically reduced in all DBMC treated patients. The most interesting finding was that the degree of microchimerism slowly increased over the years the DBMC group that had exhibited no rejection episodes. In the DBMC-living related trial, the incidence of acute rejection did not differ between groups. However, DBMC chimerism in recipient iliac crest marrow had increased more rapidly than might be predicted from results previously seen in the cadaver group, despite four times fewer DBMC infused, with the generation of T- regulartory cells in-vitro assays.
*Bone Marrow Transplantation ; Humans ; *Kidney Transplantation ; *Living Donors ; *Tissue Donors ; *Transplantation Chimera ; *Transplantation Tolerance