Publications by authors named "Ashwin Unnikrishnan"

Hypomethylating agents are frontline therapies for myelodysplastic neoplasms (MDS), yet clinical responses remain unpredictable. We conducted a phase 2 trial comparing injectable and oral azacitidine (AZA) administered over one or three weeks per four-week cycle, with the primary objective of investigating whether response is linked to in vivo drug incorporation or DNA hypomethylation. Our findings show that injection results in higher drug incorporation, but lower DNA demethylation per cycle, while global DNA methylation levels in mononuclear cells are comparable between responders and non-responders.

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  • Myelodysplastic neoplasms (MDS) and chronic myelomonocytic leukemia (CMML) are diseases caused by mutations in blood stem cells that affect blood production.
  • Hypomethylating agents (HMAs) can help manage these conditions without needing to eliminate all mutated cells, possibly improving the function of the remaining stem cells.
  • The study analyzed the mutations in different blood cell types before and after treatment to understand how these mutated stem cells behave and contribute to better blood counts following HMA therapy.
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Inorganic nanoparticles for drug delivery in cancer treatment offer many potential advantages because they can maximize therapeutic effect through targeting ligands while minimizing off-target side-effects through drug adsorption and infiltration. Although inorganic nanoparticles were introduced as drug carriers, they have emerged as having the capacity for combined therapeutic capabilities, including anticancer effects through cytotoxicity, suppression of oncogenes and cancer cell signaling pathway inhibition. The most promising advanced strategies for cancer therapy are as synergistic platforms for RNA interference (siRNA, miRNA, shRNA) and as synergistic drug delivery agents for the inhibition of cancer cell signaling pathways.

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Mouse haematopoietic stem cells (HSCs) first emerge at embryonic day 10.5 (E10.5), on the ventral surface of the dorsal aorta, by endothelial-to-haematopoietic transition.

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Chemo-resistance in acute myeloid leukemia (AML) patients is driven by leukemic stem cells (LSCs) resulting in high rates of relapse and low overall survival. Here, we demonstrate that upregulation of the splicing factor, RBM17 preferentially marks and sustains LSCs and directly correlates with shorten patient survival. RBM17 knockdown in primary AML cells leads to myeloid differentiation and impaired colony formation and in vivo engraftment.

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Cerium-based nanoparticles (CeNPs), particularly cerium oxide (CeO), have been studied extensively for their antioxidant and prooxidant properties. However, their complete redox and enzyme-mimetic mechanisms of therapeutic action at the molecular level remain elusive, constraining their potential for clinical translation. Although the therapeutic effects of both antioxidant and prooxidant mechanisms generally are attributed to Ce ↔ Ce redox switching mediation, some studies have hinted at the involvement of unknown pathways in therapeutic effects.

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  • Hypomethylating agents are used in cancer treatment, but their potential to reactivate oncogenes remains unclear.
  • In a study of myelodysplastic syndrome patients, 40% and 30% showed up-regulation of a specific oncogene after treatment, which correlated with worse outcomes.
  • CRISPR-DiR technology identified a critical CpG island for oncogene expression; this highlights the need for further research into the effects of hypomethylating agents on cancer treatment.
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  • Oncofetal protein SALL4 is important for the survival of cancer cells, but targeting it only works for patients with SALL4-positive tumors.
  • Researchers discovered that by artificially introducing SALL4 in SALL4-negative cancer cells, these cells became partially reliant on SALL4 for survival, which could be exploited for treatment.
  • Using the FDA-approved drug 5-aza-2'-deoxycytidine (DAC) to induce SALL4 expression in these cancer cells made them more sensitive to another drug, entinostat, allowing for a new therapeutic strategy for previously untreatable patients.
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  • Existing databases of non-coding RNA (ncRNA) are limited because they only include small and polyadenylated RNAs; a new comprehensive atlas includes a wider range from 300 human tissues and cell lines.
  • This study identifies thousands of new ncRNAs, increasing the known catalog by about 8%, and explores their roles in gene regulation using RNA sequencing data.
  • All findings and data are available on the R2 web portal for further research into RNA biology and function.
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  • Human endogenous retroviruses (HERV), which are mostly silent in the genome, can potentially be activated in myeloid malignancies, making them targets for immune response.
  • Researchers created a library of potential HERV-derived peptides and identified T cell recognition of 29 peptides from 18 HERV loci, with stronger responses in specific HERVs.
  • The study suggests that HERVs could be targeted in immunotherapy for cancer, as enhanced transcription of these elements is observed in patients compared to healthy individuals.
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  • RNA splicing is important for creating protein diversity, and while mutations in splicing factor genes are frequent in hematologic cancers, they're rare in acute myeloid leukemia (AML) affecting less than 20% of patients.
  • A comprehensive bioinformatics approach was utilized to analyze RNA sequencing data, revealing key splicing differences in patients with varying prognoses, even without splicing factor mutations present.
  • The study identified significant alternative splicing events in genes linked to protein translation, which were associated with negative outcomes in AML, leading to a proposed splicing signature that can improve risk assessment in patients.
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  • High-CHK1 activity is prevalent in glioblastoma (GBM) and may influence tumor development and patient survival, but its exact role is unclear.
  • Research shows that the levels of CHK1 and the oncogene CIP2A are independent indicators of poorer survival rates in glioma patients.
  • CHK1 and pSTAT3 work together to regulate CIP2A expression, and disrupting this pathway could slow down GBM growth, suggesting CIP2A as a potential target for new cancer therapies.
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  • Identification of HMGA2 is crucial for understanding hematopoietic stem cell (HSC) behavior and improving their clinical applications in treating blood-related disorders.
  • High levels of HMGA2 are found in HSCs and immature progenitors, and reducing its expression diminishes the long-term repopulation ability of cord blood-derived stem cells.
  • Enhancing HMGA2 expression in these cells boosts their reconstitution capabilities and favors development into specific blood lineages, indicating its significant role in regulating both cell growth and differentiation.
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Mutations in occur in myelodysplastic syndromes (MDS) and MDS/myeloproliferative neoplasms (MPN). mutations cluster at proline 95, with the most frequent mutation being a histidine (P95H) substitution. They undergo positive selection, arise early in the course of disease, and have been identified in age-related clonal hemopoiesis.

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  • - Myelodysplastic syndromes and chronic myelomonocytic leukemia are serious blood disorders that lead to ineffective blood cell production and may progress to acute leukemia; 5-azacytidine (AZA) is the main treatment but has limited effectiveness with only about 50% of patients responding.
  • - Research indicates that responders to AZA have more active hematopoietic progenitor cells (HPCs), while non-responders show quiescence influenced by integrin α5 (ITGA5) signaling, suggesting that a combination of AZA with an ITGA5 inhibitor might enhance treatment effectiveness.
  • - Additionally, AZA seems to trigger an inflammatory response in HPCs, and despite changes in
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  • * These mutations occur independently of when DNA replication happens and are found more often at CTCF/cohesin complex binding sites, indicating that cohesin may help stabilize CTCF's binding to DNA and affect the repair process.
  • * In melanoma cells, mutations in CTCF binding sites reduce CTCF's ability to attach to those regions and are linked to cancer-related genes, but these mutations generally appear to be under neutral selection, necessitating further investigation into their effects on cellular behavior.
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  • Aberrant gene regulatory networks in stem cells are linked to leukaemia, particularly in T-ALL and AML, with the ERG gene being a key player in these conditions.
  • Researchers used a mass spectrometry technique to identify proteins that bind to the ERG +85 enhancer region in leukaemic cells, discovering known binders and new ones like ETV6 and IKZF1.
  • ETV6 and IKZF1 were found to regulate ERG and interact with a complex network of seven transcription factors, with higher levels of these transcription factors being associated with poorer prognosis in AML patients.
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Enhancers are the primary determinants of cell identity, and specific promoter/enhancer combinations of Endoglin (ENG) have been shown to target blood and endothelium in the embryo. Here, we generated a series of embryonic stem cell lines, each targeted with reporter constructs driven by specific promoter/enhancer combinations of ENG, to evaluate their discriminative potential and value as molecular probes of the corresponding transcriptome. The Eng promoter (P) in combination with the -8/+7/+9-kb enhancers, targeted cells in FLK1 mesoderm that were enriched for blast colony forming potential, whereas the P/-8-kb enhancer targeted TIE2+/c-KIT+/CD41- endothelial cells that were enriched for hematopoietic potential.

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Inherited gene variants play an important role in malignant diseases. The transcriptional repressor growth factor independence 1 (GFI1) regulates hematopoietic stem cell (HSC) self-renewal and differentiation. A single-nucleotide polymorphism of GFI1 (rs34631763) generates a protein with an asparagine (N) instead of a serine (S) at position 36 (GFI1(36N)) and has a prevalence of 3%-5% among Caucasians.

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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.

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Recent sequencing studies have extensively explored the somatic alterations present in the nuclear genomes of cancers. Although mitochondria control energy metabolism and apoptosis, the origins and impact of cancer-associated mutations in mtDNA are unclear. In this study, we analyzed somatic alterations in mtDNA from 1675 tumors.

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