Single-cell RNA-seq supports a developmental hierarchy in human oligodendroglioma

Although human tumours are shaped by the genetic evolution of cancer cells, evidence also suggests that they display hierarchies related to developmental pathways and epigenetic programs in which cancer stem cells (CSCs) can drive tumour growth and give rise to differentiated progeny. Yet, unbiased evidence for CSCs in solid human malignancies remains elusive. Here we profile 4,347 single cells from six IDH1 or IDH2 mutant human oligodendrogliomas by RNA sequencing (RNA-seq) and reconstruct their developmental programs from genome-wide expression signatures. We infer that most cancer cells are differentiated along two specialized glial programs, whereas a rare subpopulation of cells is undifferentiated and associated with a neural stem cell expression program. Cells with expression signatures for proliferation are highly enriched in this rare subpopulation, consistent with a model in which CSCs are primarily responsible for fuelling the growth of oligodendroglioma in humans. Analysis of copy number variation (CNV) shows that distinct CNV sub-clones within tumours display similar cellular hierarchies, suggesting that the architecture of oligodendroglioma is primarily dictated by developmental programs. Subclonal point mutation analysis supports a similar model, although a full phylogenetic tree would be required to definitively determine the effect of genetic evolution on the inferred hierarchies. Our single-cell analyses provide insight into the cellular architecture of oligodendrogliomas at single-cell resolution and support the cancer stem cell model, with substantial implications for disease management

Decoupling genetics, lineages, and microenvironment in IDH-mutant gliomas by single-cell RNA-seq

Tumor subclasses differ according to the genotypes and phenotypes of malignant cells as well as the composition of the tumor microenvironment (TME).We dissected these influences in isocitrate dehydrogenase (IDH)-mutant gliomas by combining 14,226 single-cell RNA sequencing (RNA-seq) profiles from 16 patient samples with bulk RNA-seq profiles from 165 patient samples. Differences in bulk profiles between IDH-mutant astrocytoma and oligodendroglioma can be primarily explained by distinct TME and signature genetic events, whereas both tumor types share similar developmental hierarchies and lineages of glial differentiation. As tumor grade increases, we find enhanced proliferation of malignant cells, larger pools of undifferentiated glioma cells, and an increase in macrophage over microglia expression programs in TME. Our work provides a unifying model for IDH-mutant gliomas and a general framework for dissecting the differences among human tumor subclasses.National Cancer Institute (U.S.) (Grant P30-CA14051

[31] Use of platelets as drug carriers for the treatment of hematologic diseases

This chapter discusses the use of platelets as drug carriers for the treatment of hematologic diseases. The major function of platelets is to promote hemostasis. In addition, the platelet participates in immune reactions, inflammation, maintenance of vascular wall integrity, and in the evolution of vascular diseases, such as vasculitis and atherosclerosis. Vinblastine dissociated readily, whereas vincristine dissociated much more slowly, suggesting that for the in vitro drug-loading, vincristine should be a better choice than vinblastine. The platelet is a natural carrier for vinca alkaloids in vivo. In lower concentrations, different characteristics of binding and dissociation between vinblastine and vincristine were noted. Vinblastine binds rapidly and dissociates readily, whereas vincristine binds slowly and dissociates slowly. For the best use of vinblastine, constant slow infusion is to be preferred, whereas for vincristine, the best use should be platelets loaded in vitro. Selective delivery of vinca alkaloids using platelets as a carrier has been explored in the treatment of several human disorders

Immune modulation by danazol in autoimmune thrombocytopenia

Danazol, an attenuated androgen, has recently been introduced into the treatment of autoimmune thrombocytopenia. We studied its effects on T helper/inducer (Thi) and T suppressor/cytotoxic (Tsc) lymphocytes in these patients. Prospectively nine patients were studied with their T-cell subsets measured before and during danazol therapy. Increases in the percentage of Thi lymphocytes ( P < 0.05) and Thi/Tsc ratios ( P < 0.001) were observed at 1 and 3 months of treatment. Retrospectively T-cell subset data on 30 patients not treated with danazol and 36 patients on danazol were compared with those of 35 normal controls. The group not on danazol had lower percentages of Pan T ( P < 0.05), Thi ( P < 0.002), and Thi/Tsc ratios ( P < 0.00005), and had higher percentages of Tsc lymphocytes ( P < 0.01), than those of controls. In the group treated with danazol the percentages of Pan T, Thi, and Tsc lymphocytes were similar to those of controls. The percentage of Thi in the treated group was higher ( P < 0.002) than in the untreated group. Thus, danazol appears to be an effective immune modulator, correcting the abnormality of T-cell subsets seen in autoimmune thrombocytopenia by increasing the percentage of Thi lymphocytes

Danazol therapy for cyclic thrombocytopenia

Cyclic thrombocytopenia is a rare disease characterized by cyclic oscillations of platelet counts from very low to normal or higher. Severe hemorrhage may occur during the thrombocytopenic phase. To date, treatments for this disorder have been disappointing. Its pathophysiology is unknown. We report a successful outcome using danazol therapy. It can be argued that the long‐term outcome was due to spontaneous remission. However, significant improvement was noted from the outset of danazol therapy, and further improvement with long‐term therapy, as seen in the response of chronic ITP to danazol therapy. Danazol may offer lasting benefit in cyclic thrombocytopenia

Sex difference in the CD4 + CD45R + T lymphocytes in normal individuals and its selective decrease in women with idiopathic thrombocytopenic purpura

Chronic idiopathic thrombocytopenic purpura (ITP) is a well-defined autoimmune hematologic disorder. It is more common in women than men. We have shown that patients with active disease have abnormal T cell subsets which are more perturbed in women than in men and functional abnormalities that are confined to the T lymphocytes. In the current study, the anti-2H4 (CD45R) monoclonal antibody was used to divide the CD4 subset into their CD4+CD45R+ and CD4+CD45R− T lymphocytes. The sub-populations were measured in the peripheral blood of 26 women and 15 men with active ITP, 16 women and 8 men with disease in remission, and 33 normal healthy women and men. Normal women had increased percentages ( P < 0.0001) and numbers ( P < 0.005) of the CD4+CD45R+ lymphocytes compared to normal men. Women with active disease had reduced percentages and numbers of CD4+CD45R+ lymphocytes compared to normal women ( P < 0.0001) and women with disease in remission ( P < 0.001). Those women with decreased CD4+CD45R+ lymphocytes had a significantly depressed lymphocyte response to polyclonal T cell mitogens. In contrast, men with active disease had neither such phenotypic changes nor functional correlations. The percentages and numbers of CD4+CD45R− lymphocytes were not changed in either sex with active disease. In conclusion, women, but not men, with active ITP appear to possess a reduced sub-population of CD4+CD45R+ T lymphocytes

Very Low Dose Danazol in Idiopathic Thrombocytopenic Purpura and its Role as an Immune Modulator

Danazol, an attenuated androgen, has been used successfully at its conventional dose (400–800 mg/day) in the treatment of idiopathic thrombocytopenic purpura (ITP). To minimize side effects, the authors tried a very low dose (50 mg/day) regimen which has not been used in any other disease and observed its efficacy in ITP. Fifteen patients were given this dosage of danazol. Its effects on T-cell subsets, B cells, and blastogenic response to pokeweed mitogen (PWM) and staphylococcus aureus (Staph A) were studied before and during therapy. The percentage of CD3 and the percentage and numbers of CD4 were significantly increased during therapy. Responses to PWM, a T-cell dependent B cell mitogen, were also significantly elevated during therapy. However, no change in the percentage of B (CD 19) lymphocytes and response to Staph A, a polyclonal B cell mitogen, were noted. There were seven excellent-good and eight fair-poor responses in platelet counts. The excellent-good responders were found to have a more stable CD4 subset between before and during therapy compared to the fair-poor responders (p < 0.05, Fisher’s exact test). Very low dose danazol regimen, therefore, produced a significant increase in the CD4 without affecting the B cells. However, the excellent-good responder patients showed no significant increase in the CD4 lymphocytes