Specific lncRNA signatures discriminate childhood acute leukaemias: a pilot study.

BACKGROUND: Long non-coding RNAs are RNAs longer than 200 bps that do not encode any proteins and are able to alter gene expression by acting on different steps of regulation, including DNA methylation and chromatin structure. They represent a class of biomarkers of crescent interest in the hematologic and oncologic fields. Recent studies showed that the expression levels of specific lncRNAs correlate with the prognosis of paediatric patients with Acute Lymphoblastic Leukaemia. METHODS: We used NGS approaches to analyse the transcriptome of 9 childhood B-ALL patients and 6 childhood T-ALL patients, in comparison with B and T healthy lymphocytes from cord blood. We validate our findings both ex vivo, in a different cohort of 10 B-ALL and 10 T-ALL patients, and in silico using public datasets. RESULTS: We characterised the lncRNA landscape for B-ALL, T-ALL, healthy B, and T cell progenitors. From the characterised signature, we selected candidate lncRNAs able to discriminate not only B-ALL and T-ALL from healthy subjects but also between the two types of leukaemia, and subsequently validated their potential as a diagnostic tool in an additional cohort of paediatric patients. We confirmed our finding with open access transcriptomic data, comparing ALL lncRNAs with AML lncRNA landscape as well. Finally, expression correlation analyses of T-ALL selected lncRNA biomarkers suggested a possible role in lymphocyte activation and the ß-catenin signalling pathway for AC247036.1 and involvement in hedgehog signalling for HHIP-AS1. CONCLUSIONS: Our work identified a lncRNA signature discriminating paediatric B-ALL and T-ALL from healthy subjects, between them and from AML. This study provides the keystone to future clinical studies determining the theragnostic value of the characterised long non coding transcriptome panorama in a clinical setting for childhood patient management.

Quantitative Ultrasound of Proximal Phalanxes in Childhood Acute Lymphoblastic Leukemia Survivors.

Reduced bone mineral density (BMD) is a well-known complication in childhood acute lymphoblastic leukemia (ALL) survivors; the optimal method to assess BMD is still debated. We studied BMD by quantitative ultrasound (QUS) in 72 ALL survivors, and evaluated any correlation with cumulative doses of steroids and cytotoxic agents. Mean age at diagnosis was 61±45 months, while mean age at QUS was 318.3±129.6 months; mean period of follow-up was 41.2±37.8 months. Mean amplitude-dependent speed of sound z-score was -1.22±1.19. Ten survivors (13.8%) presented a z-score below -2 SD. A negative correlation was found between amplitude-dependent speed of sound z-score and age at diagnosis (P=0.01). A positive correlation was observed with length of follow-up (P=0.01). No correlation was found with cytotoxic drugs. This study represents the largest cohort of childhood ALL survivors studied by QUS. Our results suggest that QUS for its characteristics of being radiation free may be an effective option to assess BMD in pediatric age. In addition, our data outline the importance to improve the awareness about the specific expression of this complication in the pediatric age, concerning the major determinants of bone impairment, which are the disease itself and the phase of bone growth when the disease occurs.

LINC00958 as new diagnostic and prognostic biomarker of childhood acute lymphoblastic leukaemia of B cells.

Background: Paediatric acute B-cell lymphoblastic leukaemia is the most common cancer of the paediatric age. Although the advancement of scientific and technological knowledge has ensured a huge step forward in the management of this disease, there are 15%-20% cases of recurrence leading to serious complications for the patient and sometimes even death. It is therefore necessary to identify new and increasingly personalised biomarkers capable of predicting the degree of risk of B-ALL in order to allow the correct management of paediatric leukaemia patients. Methods: Starting from our previously published results, we validate the expression level of LINC00958 in a cohort of 33 B-ALL and 9 T-ALL childhood patients, using in-silico public datasets as support. Expression levels of LINC00958 in B-ALL patients stratified by risk (high risk vs. standard/medium risk) and who relapsed 3 years after the first leukaemia diagnosis were also evaluated. Results: We identified the lncRNA LINC00958 as a biomarker of B-ALL, capable of discriminating B-ALL from T-ALL and healthy subjects. Furthermore, we associated LINC00958 expression levels with the disease risk classification (high risk and standard risk). Finally, we show that LINC00958 can be used as a predictor of relapses in patients who are usually stratified as standard risk and thus not always targeted for marrow transplantation. Conclusions: Our results open the way to new diagnostic perspectives that can be directly used in clinical practice for a better management of B-ALL paediatric patients.

A Comprehensive Analysis of the Expression Profiles of KCTD Proteins in Acute Lymphoblastic Leukemia: Evidence of Selective Expression of KCTD1 in T-ALL.

Acute leukemia is the most common pediatric cancer. In most cases, this disease results from the malignant transformation of either the B-cell (B-ALL) or, less frequently, T-cell progenitors (T-ALL). Recently, a marked overexpression of KCTD15, a member of the emerging class of the potassium (K) channel tetramerization domain-containing proteins (KCTDs) has been detected in both patients and continuous cell lines as in vitro model systems. Because there is growing evidence of the key, yet diversified, roles played by KCTDs in cancers, we here report an exhaustive analysis of their expression profiles in both B-ALL and T-ALL patients. Although for most KCTDs, no significant alterations were found in these pathological states, for some members of the family, significant up- and down-regulations were detected in comparison with the values found in healthy subjects in the transcriptome analysis. Among these, particularly relevant is the upregulation of the closely related KCTD1 and KCTD15 in T-ALL patients. Interestingly, KCTD1 is barely expressed in both unaffected controls and B-ALL patients. Therefore, not only does this analysis represent the first study in which the dysregulation of all KCTDs is simultaneously evaluated in specific pathological contexts, but it also provides a promising T-ALL biomarker that could be suitable for clinical applications.

Blinatumomab in Children and Adolescents with Relapsed/Refractory B Cell Precursor Acute Lymphoblastic Leukemia: A Real-Life Multicenter Retrospective Study in Seven AIEOP (Associazione Italiana di Ematologia e Oncologia Pediatrica) Centers.

Five-year event-free survival in pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL) currently exceeds 80-85%. However, 15-20% of patients still experience a relapsed/refractory disease. From 1 January 2015 to 31 December 2020, thirty-nine patients, 0-21 years old with r/r BCP-ALL were treated with blinatumomab with the aim of inducing remission (n = 13) or reducing MRD levels (n = 26) in the frame of different multiagent chemotherapy schedules, in seven AIEOP centers. Patients were treated in compassionate and/or off-label settings and were not enrolled in any controlled clinical trials. Treatment was well tolerated; 22 (56.4%) patients reported adverse events (AE) on a total of 46 events registered, of which 27 (58.7%) were ≤2 grade according to CTCAE. Neurological AEs were 18 (39.1%); only two patients required transient blinatumomab discontinuation. Complete remission (CR) rate was 46% for the 13 patients treated with ≥5% blasts and 81% PCR/FC MRD negativity in the 26 patients with blasts < 5%. Median relapse-free survival was 33.4 months (95% CI; 7.5-59.3); median overall survival was not reached over a mean follow-up of 16 months. In our study, as in other real-life experiences, blinatumomab proved to be effective and well-tolerated, able to induce a high rate of CR and MRD negativity.

Successful management plan of COVID-19 in a pediatric hemato-oncology department: a single-centre experience.

COVID-19 pandemic raised concern about management of patients with paediatric cancer. We present the operating system that the Hemato-Oncology Department of the Santobono-Pausilipon Hospital applied. We divided our department in three zones: surveillance and screening; quarantine and COVID free, in order to screen admitted patients and to reduce the risk of cross infection. From 3 April until 29 May 2020 (56 days), 662 patients and caregivers underwent rapid serological tests for a total of 1397 assays. No patient or parent with SARS-CoV2 infection was found, demonstrating the effectiveness of COVID-19 screening process.

Toxicity and efficacy of intrathecal liposomal cytarabine in children with leukemia/lymphoma relapsing in the central nervous system: a retrospective multicenter study.

The toxicity and efficacy of intrathecal liposomal cytarabine (LC) were evaluated in children with central nervous system (CNS) relapsed/refractory acute leukemia/lymphoma. Thirty patients (male:female ratio 21:9; median age 9.4 years) with CNS relapsed/resistant disease were treated with intrathecal LC at dosages adjusted for age. Twenty-seven (90%) patients simultaneously received systemic chemotherapy, including concurrent high-dose cytarabine or methotrexate in 21 (70%) cases. Of 28 patients evaluable for response, 25 patients (89%) achieved CNS complete remission and three (11%) partial remission. The median number of intrathecal LC administrations per patient was 4. The cerebrospinal fluid was cleared after a median of 3 intrathecal LC administrations. Neurological toxicity ≥ grade 3 occurred in four (13%) patients. No permanent sequelae were observed. The median overall survival was 20.9 months and the 5-year probability of survival was 46%. These encouraging data suggest that intrathecal LC is well tolerated and effective in children with relapsed/refractory CNS leukemia/lymphoma.

Hypereosinophilia in childhood acute lymphoblastic leukaemia at diagnosis: report of 2 cases and review of the literature.

Hypereosinophilia as first clinical presentation has rarely been reported in paediatric acute lymphoblastic leukaemia. It is commonly associated with specific cytogenetic abnormalities. Although eosinophilia is considered a reactive, non-neoplastic epiphenomenon, it adversely affects patient outcomes, both in children and adults. We describe herewith two paediatric patients who had marked eosinophilia at onset of acute lymphoblastic leukaemia. We point out the importance of a correct differential diagnosis in persistent, unexplained peripheral hypereosinophilia. Clinicians should keep in mind that eosinophilia can be part of the overall pattern of acute leukaemia and therefore needs to be properly investigated. We also provide some recommendations for an appropriate approach to hypereosinophilia - related morbidities.