Immune response to COVID-19 vaccination in patients with Waldenström macroglobulinaemia who pause their BTKi therapy.

Patients with Waldenström macroglobulinaemia (WM) are at increased risk of severe COVID-19 infection and have poor immune responses to COVID-19 vaccination. This study assessed whether a closely monitored pause in Bruton's Tyrosine Kinase inhibitor (BTKi) therapy might result in an improved humoral response to a 3rd COVID-19 vaccine dose. Improved response was observed in WM patients who paused their BTKi, compared to a group who did not pause their BTKi. However, the response was attenuated after BTKi recommencement. This data contributes to our understanding of vaccination strategies in this patient group and may help inform consensus approaches in the future.

Induction of muscle-regenerative multipotent stem cells from human adipocytes by PDGF-AB and 5-azacytidine.

Terminally differentiated murine osteocytes and adipocytes can be reprogrammed using platelet-derived growth factor-AB and 5-azacytidine into multipotent stem cells with stromal cell characteristics. We have now optimized culture conditions to reprogram human adipocytes into induced multipotent stem (iMS) cells and characterized their molecular and functional properties. Although the basal transcriptomes of adipocyte-derived iMS cells and adipose tissue-derived mesenchymal stem cells were similar, there were changes in histone modifications and CpG methylation at cis-regulatory regions consistent with an epigenetic landscape that was primed for tissue development and differentiation. In a non-specific tissue injury xenograft model, iMS cells contributed directly to muscle, bone, cartilage, and blood vessels, with no evidence of teratogenic potential. In a cardiotoxin muscle injury model, iMS cells contributed specifically to satellite cells and myofibers without ectopic tissue formation. Together, human adipocyte-derived iMS cells regenerate tissues in a context-dependent manner without ectopic or neoplastic growth.

Proteomic level changes associated with S3I201 treated U87 glioma cells.

Glioblastoma multiforme is Grade IV brain tumor associated with high mortality and limited therapeutics. Signal Transducer and Activator of Transcription 3 (STAT3) is persistently active in several cancers including gliomas, and plays a major role in disease progression and survival of glioma patients, thus being a potential therapeutic target for treatment. S3I201 and its analogs inhibit the transcriptional functions of STAT3 and reduce growth of tumor tissues. Here we have studied proteomic alteration associated with S3I201 treated U87 cells using 2-DE and Isobaric tags for relative and absolute quantitation coupled with mass spectrometry. This analysis revealed 136 differentially expressed proteins which were functionally classified with gene ontology analysis. Results showed metabolism, apoptosis, cytoskeletal behaviour, cell redox homeostasis and immune response as the most affected biological processes on S3I201 treatment. Apoptosis-inducing factor 1 mitochondrial, cyclophilin A and chloride intra-cellular channel protein 1 were found to be up-regulated which possibly contributes to its anti-tumorigenic function. Several glycolytic enzymes like phosphoglycerate mutase 1 were also found to be up-regulated and its expression was validated using immunoblot. Conclusively, our study shows the downstream effects of S3I201 in U87 glioma cells and suggests its therapeutic potential. SIGNIFICANCE: Gliomas with constitutive expression can be treated with STAT3 inhibitors. S3I201, a STAT3 inhibitor, reduces the growth of glioma cells thus could be studied further for its application as anti-glioma agent. This study investigated proteomic alteration associated with S3I201 in U87 cells using complementary proteomic approaches, and our findings suggest that S3I201 influences central metabolism, apoptosis, cytoskeletal behaviour, cell redox homeostasis and immune response as the most affected biological processes which altogether contribute to its anti-tumorigenic activity. Several proteins were identified which may serve as prognostic or predictive markers in GBM. Apoptosis-inducing factor 1 mitochondrial and cyclophilin A were identified as potential therapeutic targets and further investigations on these candidates may facilitate therapeutic development and suggests that GBM therapy can be improved by targeting cellular metabolism and by using immunotherapy.

PDGF-AB and 5-Azacytidine induce conversion of somatic cells into tissue-regenerative multipotent stem cells.

Current approaches in tissue engineering are geared toward generating tissue-specific stem cells. Given the complexity and heterogeneity of tissues, this approach has its limitations. An alternate approach is to induce terminally differentiated cells to dedifferentiate into multipotent proliferative cells with the capacity to regenerate all components of a damaged tissue, a phenomenon used by salamanders to regenerate limbs. 5-Azacytidine (AZA) is a nucleoside analog that is used to treat preleukemic and leukemic blood disorders. AZA is also known to induce cell plasticity. We hypothesized that AZA-induced cell plasticity occurs via a transient multipotent cell state and that concomitant exposure to a receptive growth factor might result in the expansion of a plastic and proliferative population of cells. To this end, we treated lineage-committed cells with AZA and screened a number of different growth factors with known activity in mesenchyme-derived tissues. Here, we report that transient treatment with AZA in combination with platelet-derived growth factor-AB converts primary somatic cells into tissue-regenerative multipotent stem (iMS) cells. iMS cells possess a distinct transcriptome, are immunosuppressive, and demonstrate long-term self-renewal, serial clonogenicity, and multigerm layer differentiation potential. Importantly, unlike mesenchymal stem cells, iMS cells contribute directly to in vivo tissue regeneration in a context-dependent manner and, unlike embryonic or pluripotent stem cells, do not form teratomas. Taken together, this vector-free method of generating iMS cells from primary terminally differentiated cells has significant scope for application in tissue regeneration.