The dysregulation of m6A-related genes recognized as 'writers', 'readers', and 'erasers' is reported to be involved in the initiation, progression, and drug resistance of acute myeloid leukemia (AML). In the present study, we investigated the expression levels of various readers, writers, and erasers in pediatric AML patients. Additionally, we categorized the patients according to the molecular subtyping of common mutations and recurrent fusions and correlated the expression of m6A-associated genes with different molecular subtypes and evaluated their prognostic and clinical implications. A total of fifty-seven patients with pediatric de novo AML were enrolled in the study. The study cohort consisted of 41 males and 16 females with a median age of 7 years (range 1 to 12 years). A high expression of m6A RNA modification complex genes was noted in AML patients. Among the writers, METTL3 and METTL14 were found to be upregulated in 19 and 17 patients, the readers YTHDF1 and YTHDF2 showed higher expression in 6 and 10 patients, while a high expression of erasers FTO and ALKBH5 was found in 28 patients and 1 patient, respectively. Further, the expression of m6A regulators showed a significant association with genetic alterations including FLT3-ITD, RBM15::MKL fusions and NPM1 mutations. Additionally, while evaluating the prognostic implications, both the readers YTHDF1 and YTHDF2 showed a significant correlation with TLC at diagnosis (p < 0.05). Further, Kaplan-Meier estimation showed a poor event-free survival in cases with the overexpression of YTHDF1 (log-rank p = 0.028). Additionally, we noted a strong correlation between YTHDF1 overexpression and treatment-related mortality (log-rank p < 0.001), and a nearly significant correlation with YTHDF2 expression in such patients (log-rank p = 0.053) at a median follow-up of 8 months. Thus, our data suggest that m6A genes, especially readers YTHDF1 and YTHDF2, are involved in the disease prognosis of AML and probably function in an integrated manner with other m6A-modifying genes to subsequently play a role in AML pathogenesis.

RNA modification is the critical mechanism for regulating post-transcriptional processes. There are more than 150 RNA modifications reported so far, among which N6-Methyladenosine is the most prevalent one. M6A RNA modification complex consists of ‘writers’, ‘readers’ and ‘erasers’ which together in a group catalyze, recognize and regulate the methylation process of RNA and thereby regulate the stability and translation of mRNA. The discovery of erasers also known as demethylases, revolutionized the research on RNA modifications as it revealed that this modification is reversible. Since then, various studies have focused on discovering the role of m6A modification in various diseases especially cancers. Aberrant expression of these ‘readers’, ‘writers’, and ‘erasers’ is found to be altered in various cancers resulting in disturbance of cellular homeostasis. Acute leukemias are the most common cancer found in pediatric patients and account for 20% of adult cases. Dysregulation of the RNA modifying complex have been reported in development and progression of hematopoietic malignancies. Further, targeting m6A modification is the new approach for cancer immunotherapy and is being explored extensively. This review provides detailed information about current information on the role of m6A RNA modification in acute leukemia and their therapeutic potential.

Introduction T-cell acute lymphoblastic leukemia (T-ALL) is a genetically heterogeneous disease with poor prognosis and inferior outcome. Although multiple studies have been perform on genomics of T-ALL, data from Indian sub-continent is scarce. Methods In the current study we aimed to identify the genetic variability of T-ALL in an Indian cohort of pediatric (age ≤ 12 years) T-ALL patients ( n = 25) by whole transcriptome sequencing along with whole exome sequencing and correlated the findings with clinical characteristics and disease outcome. Results The median age was 7 years (range 3 -12 years). RNA sequencing revealed a definitive fusion event in 14 cases (56%) (including a novel fusions) with STIL::TAL1 in 4 (16%), followed by NUP21::ABL1, TCF7::SPI1, ETV6::HDAC8, LMO1::RIC3, DIAPH1::JAK2, SETD2::CCDC12 and RCBTB2::LPAR6 in 1 (4%) case each. Significant aberrant expression was noted in RAG1 (64%), RAG2 (80%), MYCN (52%), NKX3-1 (52%), NKX3-2 (32%), TLX3 (28%), LMO1 (20%) and MYB (16%) genes. WES data showed frequent mutations in NOTCH1 (35%) followed by WT1 (23%), FBXW7 (12%), KRAS (12%), PHF6 (12%) and JAK3 (12%). Nearly 88.2% of cases showed a deletion of CDKN2A/CDKN2B/MTAP genes. Clinically significant association of a better EFS and OS ( p =0.01) was noted with RAG2 over-expression at a median follow up of 22 months, while a poor EFS ( p =0.041) and high relapse rate ( p =0.045) was observed with MYB over-expression. Conclusion Overall, the present study demonstrates the frequencies of transcriptomic and genetic alterations from Indian cohort of pediatric T-ALL and is a salient addition to current genomics data sets available in T-ALL.

Introduction Pediatric T-cell acute lymphoblastic leukemia (T-ALL) poses significant challenges due to its aggressive nature and resistance to standard treatments. Long non-coding RNAs (lncRNAs) have emerged as potential biomarkers and therapeutic targets in leukemia. This study aims to characterize the lncRNA landscape in pediatric T-ALL, identify specific lncRNAs signatures, and assess their clinical relevance. Methods RNA sequencing was performed on T-ALL patient and control samples. Differential expression analysis identified dysregulated lncRNAs and mRNAs. Functional enrichment analysis revealed potential roles of these lncRNAs in cancer pathogenesis. Validation of candidate lncRNAs was conducted using real-time PCR. Clinical correlations were assessed, including associations with patients’ clinical characteristics and survival outcomes. Results Analysis identified 674 dysregulated lncRNAs in pediatric T-ALL, with LINC01221 and CRNDE showing the most interactions in cancer progression pathways. Functional enrichment indicated involvement in apoptosis, survival, proliferation, and metastasis. Top 10 lncRNAs based on adjusted p value < 0.05 and Fold Change > 2 were selected for validation. Seven lncRNAs LINC01221, PCAT18, LINC00977, RP11-620J15.3, RP11-472G21.2, CTD-2291D10.4, and CRNDE showed correlation with RNA sequencing data. RP11-472G21.2 and CTD-2291D10.4 were highly expressed in T-ALL patients, with RP11-620J15.3 correlating significantly with better overall survival ( p = 0.0007) at a median follow up of 32 months. The identified lncRNAs were further analysed in B-ALL patients. Distinct lncRNAs signatures were noted, distinguishing T-ALL from B-ALL and healthy controls, with lineage-specific overexpression of LINC01221 ( p < 0.0001), RP11-472G21.2 ( p < 0.001) and CRNDE ( p = 0.04) in T-ALL. Conclusion This study provides insights into the lncRNA landscape of pediatric T-ALL, offering potential diagnostic and prognostic markers. RP11-620J15.3 emerges as a promising prognostic marker, and distinct lncRNAs signatures may aid in the differentiation of T-ALL subtypes. Further research with larger cohorts is warranted to validate these findings and advance personalized treatment strategies for pediatric T-ALL patients.

T-cell Acute Lymphoblastic Leukemia (T-ALL) is a highly aggressive form of ALL with at least 25

Methods: Forty pediatric (0–12 years) B-ALL DNA samples (20 paired Diagnosis-Relapse) and an additional six B-ALL DNA samples (without relapse at 3 years post treatment), as the non-relapse arm, were retrieved from the biobank for advanced genomic analysis. Deep sequencing (1050–5000X; mean 1600X) was performed using a custom NGS panel of 74 genes incorporating unique molecular barcodes. Results: A total 47 major clones (>25% VAF) and 188 minor clones were noted in 40 cases after bioinformatic data filtering. Of the forty-seven major clones, eight (17%) were diagnosis-specific, seventeen (36%) were relapse-specific and 11 (23%) were shared. In the control arm, no pathogenic major clone was noted in any of the six samples. The most common clonal evolution pattern observed was therapy-acquired (TA), with 9/20 (45%), followed by M-M, with 5/20 (25%), m-M, with 4/20 (20%) and unclassified (UNC) 2/20 (10%). The TA clonal pattern was predominant in early relapses 7/12 (58%), with 71% (5/7) having major clonal mutations in the NT5C2 or PMS2 gene related to thiopurine-dose response. In addition, 60% (3/5) of these cases were preceded by an initial hit in the epigenetic regulator, KMT2D. Mutations in common relapse-enriched genes comprised 33% of the very early relapses, 50% of the early and 40% of the late relapses. Overall, 14/46 (30%) of the samples showed the hypermutation phenotype, of which the majority (50%) had a TA pattern of relapse. Conclusions: Our study highlights the high frequency of early relapses driven by TA clones, demonstrating the need to identify their early rise during chemotherapy by digital PCR.

Thiopurine drugs like 6-Mercaptopurine (6MP) are the cornerstone of maintenance therapy in acute lymphoblastic leukemia (ALL). A recently described variant in alpha-ketoglutarate dependent dioxygenase (FTO) gene has been reported to play an important role in thiopurine induced myelosuppression. In this study, we genotyped a coding variant (p.Ala134Thr, rs79206939) and an intronic variant (rs16952570) of FTO in 174 Indian children (age ≤ 12 years) with ALL on maintenance phase of chemotherapy and examined correlation with the risk of thiopurine induced myelosuppression and hepatic toxicity. The prevalence of FTO-rs16952570 polymorphism was 18.4

PurposeBCR::ABL1-like pre-B-ALL comprises a myriad of genetic lesions making molecular diagnosis challenging and expensive. Its frequency and outcome are less studied in resource-constraint settings.Methods154 pre-B-ALL cases (0-12 years) were enrolled as group 1 (37 cases of B-other-ALL) and group 2 (117 patients with recurrent translocations/ hyperdiploidy). Group 1 was evaluated for BCR::ABL1-like genetic lesions and copy-number abnormalities (CNAs) as per our published PACE approach supplemented with targeted RNA sequencing.ResultsBCR::ABL1-like frequency was 5.2% (8 of 154) and 22% (8 of 37) with the PACE approach alone in the whole and B-other-ALL cohort, respectively. The addition of targeted RNA-sequencing had led to the frequency increasing to 9% (14 of 154) and 38% (14 of 37) in the whole and B-other-ALL cohort, respectively. P2RY8::CRLF2, IGH::CRLF2, and RCSD1::ABL1 were noted in 8 (57.1%), 4 (28.6%), and 2 (14.3%) patients, respectively. CNAs were noted in 56.7% (21 of 37) of patients. The BCR::ABL1-like group had a significantly higher initial WBC count of ≥ 50,000/mm3 (71.4%; P < .001) than group 2. The 4-year OS, EFS, RFS of group 1 was not statistically different from group 2, though RFS was borderline poor (84.2%, 51.7%, 56.9% Vs. 82.6%, 62.9%, 78% [P - .42, P - .53, P - .059]). The 4-year EFS and RFS for BCR::ABL1-like cases was 70.7% and 76.6%, respectively.ConclusionsThe sensitivity of detecting BCR::ABL1-like lesions had increased significantly from 22% using the PACE approach alone to 38% in B-other-ALLs with the integrated approach. Although outcomes were not statistically different, a higher percentage of relapses were noted in the B-other-ALL group.

Abstract Introduction: Current study is a 4 year experience in diagnosis and screening of bone marrow failure cases using a targeted sequencing panel. Methods: A total of 171 cases underwent targeted NGS and were categorized as suspected inherited bone marrow failure syndrome (IBMFS) group (106/62%) and idiopathic aplastic anemia (IAA) group (65/38%) based on clinical and laboratory criteria. Results: 110 (64%) were pediatric (0-12 years) and 61 (36%) adolescent and adults (13-47 years). In suspected IBMFS group, 47 (44%) were positive for a pathogenic variation while in IAA group, 8 (12%) revealed a silent germline pathogenic variation. Whole exome sequencing performed in 15/61 suspected IBMFS group cases, revealed a clinically important variation in 3 (20%) cases. The targeted panel helped in establishing a diagnosis in 44% (27/61) of phenotypically heterogenous unclassified bone marrow failure syndrome cases and also led to amendment of clinical diagnosis in 5 (4.7%) of genotyped cases. Conclusion: Overall targeted NGS panel yield was comparable to western data, however, this was achievable at 1/5th the cost, making it a cost-effective panel for resource constraint settings.

T cell acute lymphoblastic leukaemia (T-ALL) is a genetically heterogeneous and aggressive form of malignancy. Although a number of recurrent fusion genes are reported in T-ALL, their involvement in disease stratification and therapeutic intervention is still controversial. Considering the prognostic value of STIL-TAL1 fusion and tyrosine kinase inhibitor (TKI) based therapeutic potential of NUP214-ABL1, the present study aimed to investigate their frequency and clinical correlation in pediatric T-ALL cases. Our cohort consisted of 48 T-ALL pediatric cases (age ≤ 12 years) with a median age of 6 years and male to female ratio of 20.5:1. The median TLC of the study group was noted to be 220,000/ cu mm with a range from 26,810/cu mm to 785,430/cu mm. By MLPA and RT-PCR analysis we observed that 11/48 cases (23%) showed STIL-TAL1 fusion and 4/48 cases (8.3%) had NUP214-ABL1 fusion gene. Both of the fusion genes did not show any significant correlation with any of the clinico-hematological or treatment outcome parameters. However, upon analysis of copy number variations (CNVs) with other clinically relevant genes, we found significant correlation between LEF1 (p = 0.024) and PTEN (p = 0.049) gene deletions with STIL/TAL1 fusion in T-ALL patients. NUP214-ABL1 fusion gene did not reveal any association with either CNVs or with survival. Although limited with the small cohort size and follow up, our study supports the similar frequency of these fusions as compared to other Asian and Western studies and also highlights utility of MLPA technique as a good diagnostic modality to screen for both STIL-TAL1 and NUP214-ABL1 fusions in a single assay with additional data on secondary copy number changes.