Torque teno mini virus as a cause of childhood acute promyelocytic leukemia lacking PML/RARA fusion

Acute Promyelocytic Leukemia With Torque Teno Mini Virus::RARA Fusion: An Approach to Screening and Diagnosis

Acute promyelocytic leukemia (APL) with variant RARA translocation is linked to over 15 partner genes. Recent publications encompassing 6 cases have expanded the spectrum of RARA partners to torque teno mini virus (TTMV). This entity is likely underrecognized due to the lack of clinician and pathologist familiarity, inability to detect the fusion using routine testing modalities, and informatic challenges in its recognition within next-generation sequencing (NGS) data. We describe a clinicopathologic approach and provide the necessary tools to screen and diagnose APL with TTMV::RARA using existing clinical DNA- or RNA-based NGS assays, which led to the identification of 4 cases, all without other known cytogenetic/molecular drivers. One was identified prospectively and 3 retrospectively, including 2 from custom automated screening of multiple data sets (50,257 cases of hematopoietic malignancy, including 4809 acute myeloid leukemia/myeloid sarcoma/APL cases). Two cases presented as myeloid sarcoma, including 1 with multiple relapses after acute myeloid leukemia-type chemotherapy and hematopoietic stem cell transplant. Two cases presented as leukemia, had a poor response to induction chemotherapy, but achieved remission upon reinduction (including all-trans retinoic acid in 1 case) and subsequent hematopoietic stem cell transplant. Neoplastic cells demonstrated features of APL including frequent azurophilic granules and dim/absent CD34 and HLA-DR expression. RARA rearrangement was not detected by karyotype or fluorescent in situ hybridization. Custom analysis of NGS fusion panel data identified TTMV::RARA rearrangements and, in the prospectively identified case, facilitated monitoring in sequential bone marrow samples. APL with TTMV::RARA is a rare leukemia with a high rate of treatment failure in described cases. The diagnosis should be considered in leukemias with features of APL that lack detectable RARA fusions and other drivers, and may be confirmed by appropriate NGS tests with custom informatics. Incorporation of all-trans retinoic acid may have a role in treatment but requires accurate recognition of the fusion for appropriate classification as APL.

History of Developing Acute Promyelocytic Leukemia Treatment and Role of Promyelocytic Leukemia Bodies

The story of acute promyelocytic leukemia (APL) discovery, physiopathology, and treatment is a unique journey, transforming the most aggressive form of leukemia to the most curable. It followed an empirical route fueled by clinical breakthroughs driving major advances in biochemistry and cell biology, including the discovery of PML nuclear bodies (PML NBs) and their central role in APL physiopathology. Beyond APL, PML NBs have emerged as key players in a wide variety of biological functions, including tumor-suppression and SUMO-initiated protein degradation, underscoring their broad importance. The APL story is an example of how clinical observations led to the incremental development of the first targeted leukemia therapy. The understanding of APL pathogenesis and the basis for cure now opens new insights in the treatment of other diseases, especially other acute myeloid leukemias.

Case report of pediatric TTMV-related acute promyelocytic leukemia with central nervous system infiltration and rapid accumulation of RARA-LBD mutations

TTMV::RARA is a recently reported fusion gene associated with acute promyelocytic leukemia (APL), caused by the integration of torque teno mini virus (TTMV) genomic fragments into the second intron of the RARA gene. Currently, there have been only six documented cases, with clinical presentations showing significant variability. Although initial responses to all-trans retinoic acid (ATRA) treatment may be observed in patients with TTMV::RARA-APL, the overall prognosis remains unfavorable among infrequent reported cases. This article presents a pediatric case that manifested as PML::RARA-negative APL with central nervous system involvement at onset. The patient experienced both intramedullary and extramedullary relapse one year after undergoing allogeneic hematopoietic stem cell transplantation. Upon identification as TTMV::RARA-APL and subsequent administration of two rounds of ATRA-based treatment, the patient rapidly developed multiple RARA ligand-binding domain mutations and demonstrated extensive resistance to ATRA and various other therapeutic interventions. Additionally, the patient experienced ARID1A mutant clone expansion and progressed MYC-targeted gene activation. This case represents the first documentation of extramedullary involvement at both the initial diagnosis and relapse stages, emphasizing the intricate clinical features and challenges associated with the rapid accumulation of multiple ATRA-resistant mutations in TTMV::RARA-APL, characterizing it as a distinct and complex sub-entity of atypical APL.

Ultrasensitive detection of genetic variation based on dual signal amplification assisted by isothermal amplification and cobalt oxyhydroxide nanosheets/quantum dots

PML/RARα fusion gene (P/R) is the characteristic signature genetic variation of acute promyelocytic leukemia (APL). Here, by integrating triple-stranded DNA hybridization-triggered strand displacement amplification (tri-HT SDA) and cobalt oxyhydroxide nanosheets/quantum dots (CoOOH/QD)-based amplification, we constructed a novel biosensor of easy-operating, time-saving and high sensitivity for detecting P/R to meet clinical needs. Owing to the specific recognition and efficient amplification of tri-HT SDA as well as impressive anti-interference and considerable amplification of CoOOH/QD, this biosensor demonstrated a wide dynamic range (10 fM to 10 nM) with a low limit of detection (5.50 fM) in P/R detection. Additionally, this biosensor could detect P/R spiked into human serum with good recoveries and relative standard deviation (RSD), thus potentially exhibiting ultrasensitive and specific nuclear acid sequence detection ability in clinical diagnosis owing to combing isothermal amplification and nanomaterials.

Brief Report: The Virome of Bladder Tumors Arising in People Living With HIV

BACKGROUND

People living with HIV (PLWH) have elevated risk for developing virus-related cancers. Bladder cancer risk is not increased in PLWH but is elevated among immunosuppressed solid organ transplant recipients (SOTRs). BK polyomavirus and, to a lesser extent, other viruses have been detected in bladder cancers from SOTRs.

OBJECTIVE

To characterize the virome of bladder tumors in PLWH.

DESIGN

Retrospective case series.

METHODS

We sequenced DNA and RNA from archived formalin-fixed bladder tumors from PLWH. Nonhuman reads were assembled and matched to a database of known viruses.

RESULTS

Fifteen bladder tumors from PLWH (13 carcinomas, 2 benign tumors) were evaluated. Fourteen tumors were in men, and the median age at diagnosis was 59 years (median CD4 count 460 cells/mm3). All but 1 tumor yielded both sufficient DNA and RNA. One bladder cancer, arising in a 52-year-old man with a CD4 count of 271 cells/mm3, manifested diverse Alphatorquevirus DNA and RNA sequences. A second cancer arising in a 58-year-old male former smoker (CD4 count of 227 cells/mm3) also showed Alphatorquevirus and Gammatorquevirus DNA sequences. Neither tumor exhibited viral integration.

CONCLUSIONS

Alphatorqueviruses and Gammatorqueviruses are anelloviruses, which have also been detected in bladder cancers from SOTRs, but anelloviruses are common infections, and detection may simply reflect increased abundance in the setting of immunosuppression. The lack of detection of BK polyomavirus among bladder tumors from PLWH parallels the lower level of bladder cancer risk seen in PLWH compared with SOTRs, indirectly supporting a role for BK polyomavirus in causing the excess risk in SOTRs.

Preparation of chitosan/retinoic acid @ nanocapsules/TiO2 self-cleaning one-dimensional photonic crystals and the study of the visual detection of acute promyelocytic leukemia

Sample exposure to air during optical detection leads to the widespread dispersal of microorganisms in the air, posing a health threat to patients and healthcare workers and potentially causing numerous nosocomial infections. In this study, a TiO₂/CS-nanocapsules-Va visualization sensor was developed by alternatively spin-coating TiO₂, CS and nanocapsules-Va. The uniformly distributed TiO₂ can endow the visualization sensor with good photocatalytic performance, and the nanocapsules-Va can bind specifically to the antigen and change its volume. The research results showed that the visualization sensor cannot only detect acute promyelocytic leukemia conveniently, quickly and accurately, but also kill bacteria, decompose organic residues in blood samples under the influence of sunlight, and have an extensive application prospect in substance detection and disease diagnosis.

Identification and Genomic Characterization of Anelloviruses in Patients with Chronic Lymphocytic Leukemia

Purpose. Metagenomics has revealed that, in addition to the digestive tract, certain viruses are also commonly found in human blood. In order to explore and monitor potential novel viruses, three serum samples of patients with chronic lymphocytic leukemia were collected at the No. 2 People’s Hospital of Changshu City, China. Materials and Methods. We sequenced the virome of serum samples from three patients with chronic lymphocytic leukemia using an unbiased viral metagenomic approach and subsequently performed maximum likelihood phylogenetic analysis using MrBayes v3.2. In addition, pairwise sequence comparison was produced with ORF1 amino acid sequences of anelloviruses within Bayesian consensus tree. Results. Partial genomes of eight different anelloviruses containing the complete ORF1 gene have been identified. BLASTp results showed that the amino acid sequence identity of these viruses with the best match in GenBank was between 56.22% and 95.43%. Phylogenetic analysis based on ORF1 indicated that seven sequences belong to the genus Alphatorquevirus and one sequence belongs to the genus Gammatorquevirus. Conclusions. This virological investigation has increased our understanding of the diversity of anelloviruses in human serum, but further study is needed to verify its potential correlation with disease.

Chemotherapy-free treatment for acute promyelocytic leukemia: the pediatric view of a revolutionary tale

The addition of all-trans retinoic acid (ATRA) to the standard anthracycline-base chemotherapy has revolutionized the treatment of acute promyelocytic leukemia (APL) over the last decades, becoming a model for precision medicine. The protocols based on the combination of ATRA and chemotherapy allowed obtaining excellent response rates both for children and adults. However, the persistence of anthracycline chemotherapy as a backbone was a matter of concern for both acute and long-term complications. Efforts in reducing anthracycline cumulative dose or even eliminating anthracycline have been pursued in more recent pediatric protocols thanks to the introduction of arsenic trioxide (ATO). The impressive results of the ATRA/ATO combinations led to the introduction of protocols completely chemotherapy-free for standard-risk adult patients as the standard of care, whereas pediatric chemo-free protocols are still currently under evaluation. In this Review, we will critically retrace the history of this unique revolution in precision medicine, discussing the peculiar advantages for pediatric patients with APL.

Torque teno mini virus driven childhood acute promyelocytic leukemia: The third case report and sequence analysis

In this manuscript, we report torque teno mini virus (TTMV) as a cause of acute promyelocytic leukemia (APL) lacking PML::RARA in a 3-year-old boy. Astolfi et al. firstly identified partial integration of the TTMV genome into RARA intron 2, which resulted in in-frame TTMV::RARA fusion in two APL-like pediatric cases without PML::RARA in November 2021. This fascinating report identified an unexpected exogenous genetic cause of APL and could be of great importance for diagnosing and managing APL. Here we report the third childhood APL-like case caused by TTMV integration and investigate the location and structure of the integrated TTMV sequence. These findings suggest TTMV::RARA is a recurrent cause of APL lacking PML::RARA. Considering the widespread prevalence of TTMV in the population, more TTMV::RARA positive APL-like cases might remain to be identified. Establishing a bioinformatic analysis strategy optimized for the highly variable TTMV genome sequence may facilitate the identification of TTMV::RARA by whole transcript sequencing. An effective PCR protocol to identify TTMV::RARA based on a profound analysis of the conservation of TTMV segments in the fusion transcript is also expected. Also, further investigation is needed to elucidate the oncogenic mechanisms of TTMV integration and the clinical features of TTMV::RARA positive patients.

Case Report: Successful therapy with all-trans retinoic acid combined with chemotherapy followed by hematopoietic stem cell transplantation for acute promyelocytic leukemia carrying the BCOR-RARA fusion gene

Acute promyelocytic leukemia (APL) is characterized by the balanced translocation of chromosomes 15 and 17, resulting in the formation of PML-RARA fusion gene. More than 98% of APL have PML-RARA fusion, and less than 2% have other types of RARA gene partners, which named variant APL (vAPL). In the present study, we reported a vAPL with BCOR-RARA, which was the third case of BCOR-RARA APL published. The patient achieved complete remission (CR) with all-trans retinoic acid (ATRA) monotherapy, and molecular CR with ATRA plus standard chemotherapy. After that, he underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT) and ATRA maintenance and maintained a molecular CR status. This case provided valuable insights into the accurate identification of vAPL. Moreover, ATRA combined with chemotherapy followed by allo-HSCT was suggested as an optimal choice for those vAPL patients who had a high risk of relapse.

Ubiquitin specific peptidase 11 as a novel therapeutic target for cancer management

Ubiquitination is a critical biological process in post-translational modification of proteins and involves multiple signaling pathways in protein metabolism, apoptosis, DNA damage, cell-cycle progression, and cancer development. Deubiquitinase, a specific enzyme that regulates the ubiquitination process, is also thought to be closely associated with the development and progression of various cancers. In this article, we systematically review the emerging role of the deubiquitinase ubiquitin-specific peptidase 11 (USP11) in many cancer-related pathways. The results show that USP11 promotes or inhibits the progression and chemoresistance of different cancers, including colorectal, breast, ovarian, and hepatocellular carcinomas, via deubiquitinating several critical proteins of cancer-related pathways. We initially summarize the role of USP11 in different cancers and further discuss the possibility of USP11 as a therapeutic strategy.

Circulating microbial content in myeloid malignancy patients is associated with disease subtypes and patient outcomes

Although recent work has described the microbiome in solid tumors, microbial content in hematological malignancies is not well-characterized. Here we analyze existing deep DNA sequence data from the blood and bone marrow of 1870 patients with myeloid malignancies, along with healthy controls, for bacterial, fungal, and viral content. After strict quality filtering, we find evidence for dysbiosis in disease cases, and distinct microbial signatures among disease subtypes. We also find that microbial content is associated with host gene mutations and with myeloblast cell percentages. In patients with low-risk myelodysplastic syndrome, we provide evidence that Epstein-Barr virus status refines risk stratification into more precise categories than the current standard. Motivated by these observations, we construct machine-learning classifiers that can discriminate among disease subtypes based solely on bacterial content. Our study highlights the association between the circulating microbiome and patient outcome, and its relationship with disease subtype.