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The down-modulation of the β-catenin antagonist Chibby 1 (CBY1) associated with the BCR-ABL1 fusion gene of chronic myeloid leukemia (CML) contributes to the aberrant activation of β-catenin, particularly in leukemic stem cells (LSC) resistant to tyrosine kinase (TK) inhibitors. It is, at least partly, driven by transcriptional events and gene promoter hyper-methylation. Here we demonstrate that it also arises from reduced protein stability upon binding to 14-3-3σ adapter protein. CBY1/14-3-3σ interaction in BCR-ABL1+ cells is mediated by the fusion protein TK and AKT phosphorylation of CBY1 at critical serine 20, and encompasses the 14-3-3σ binding modes I and II involved in the binding with client proteins. Moreover, it is impaired by c-Jun N-terminal kinase (JNK) phosphorylation of 14-3-3σ at serine 186, which promotes dissociation of client proteins. The ubiquitin proteasome system UPS participates in reducing stability of CBY1 bound with 14-3-3σ through enhanced SUMOylation. Our results open new routes towards the research on molecular pathways promoting the proliferative advantage of leukemic hematopoiesis over the normal counterpart. [ABSTRACT FROM AUTHOR]

Abstract: Autophagy protects chronic myeloid leukemia stem cells from tyrosine kinase inhibitors hence supporting the disease persistence under therapy. However, the signals involved in autophagy regulation relative to BCR–ABL1 are still elusive. The autophagic flux proceeding from the inhibition of BCR–ABL1 tyrosine kinase represents a regulatory mechanism of β-catenin stability through events encompassing the activation of calpain, which targets β-catenin for proteasome-independent degradation. Accordingly, its inactivation may contribute to induce autophagy and autophagy induction may, in turn, promote β-catenin autolysosomal degradation to originate a regulatory loop where β-catenin plays a central role in cell decision between life and death. Here we proved that the cytoplasmic accumulation of β-catenin driven by up-regulation of its antagonist Chibby1 is a component of autophagy induction in response to imatinib in BCR–ABL1+ cells opposing the apoptotic death. It is contingent upon ER stress and elevation of free Ca2+ cytosolic concentration and results in the calpain cleavage into a 28kDa fragment implicated in β-catenin proteasome-independent degradation. More important for BCR–ABL1+ cell survival and proliferation following IM treatment, might be the calpain-mediated cleavage of β-catenin accumulated within the cytoplasmic compartment into a 75kDa fragment, still owning TCF-dependent transcriptional activity. Such a β-catenin fragment might be crucial for BCR–ABL1+ cell survival following the fusion protein TK inhibition. [Copyright &y& Elsevier]

Beta Catenin signaling is critical for the self-renewal of leukemic stem cells in chronic myeloid leukemia. It is driven by multiple events, enhancing beta catenin stability and promoting its transcriptional co-activating function. We investigated the impact of BCR-ABL1 on Chibby1, a beta catenin antagonist involved in cell differentiation and transformation. Relative proximity of the Chibby1 encoding gene (C22orf2) on chromosome 22q12 to the BCR breakpoint (22q11) lets assume its involvement in beta catenin activation in chronic myeloid leukemia as a consequence of deletions of distal BCR sequences encompassing one C22orf2 allele. Forty patients with chronic myeloid leukemia in chronic phase were analyzed for C22orf2 relocation and Chibby1 expression. Fluorescent in situ hybridization analyses established that the entire C22orf2 follows BCR regardless of chromosomes involved in the translocation. In differentiated hematopoietic progenitors (bone marrow mononuclear cell fractions) of 30/40 patients, the expression of Chibby1 protein was reduced below 50% of the reference value (peripheral blood mononuclear cell fractions of healthy persons). In such cell context, Chibby1 protein reduction is not dependent on C22orf2 transcriptional downmodulation; however, it is strictly dependent upon BCR-ABL1 expression because it was not observed at the moment of major molecular response under tyrosine kinase inhibitor therapy. Moreover, it was not correlated with the disease prognosis or response to therapy. Most importantly, a remarkable Chibby1 reduction was apparent in a putative BCR-ABL1+ leukemic stem cell compartment identified by a CD34+ phenotype compared to more differentiated hematopoietic progenitors. In CD34+ cells, Chibby1 reduction arises from transcriptional events and is driven by C22orf2 promoter hypermethylation. These results advance low Chibby1 expression associated with BCR-ABL1 as a component of beta catenin signaling in leukemic stem cells. [ABSTRACT FROM AUTHOR]

Abstract: Chronic myeloid leukemia (CML) is a myeloproliferative disease caused by the constitutive tyrosine kinase (TK) activity of the BCR-ABL fusion protein. However, the phenotype of leukemic stem cells (LSC) is sustained by β catenin rather than by the BCR-ABL TK. β catenin activity in CML is contingent upon its stabilization proceeding from the BCR-ABL-induced phosphorylation at critical residues for interaction with the Adenomatous polyposis coli (APC)/Axin/glycogen synthase kinase 3 (GSK3) destruction complex or GSK3 inactivating mutations. Here we studied the impact of β catenin antagonist Chibby (CBY) on β catenin signaling in BCR-ABL1+ cells. CBY is a small conserved protein which interacts with β catenin and impairs β catenin-mediated transcriptional activation through two distinct molecular mechanisms: 1) competition with T cell factor (TCF) or lymphoid enhancer factor (LEF) for β catenin binding; and 2) nuclear export of β catenin via interaction with 14-3-3. We found that its enforced expression in K562 cell line promoted β catenin cytoplasmic translocation resulting in inhibition of target gene transcription. Moreover, cytoplasmic accumulation of β catenin activated the endoplasmic reticulum (ER) stress-associated pathway known as unfolded protein response (UPR). CBY-driven cytoplasmic accumulation of β catenin is also a component of BCR-ABL1+ cell response to the TK inhibitor Imatinib (IM). It evoked the UPR activation leading to the induction of BCL2-interacting mediator of cell death (BIM) by UPR sensors. BIM, in turn, contributed to the execution phase of apoptosis in the activation of ER resident caspase 12 and mobilization of Ca2+ stores. [Copyright &y& Elsevier]

Abstract: The advantage of Aurora kinase (AK) inhibitors in chronic myeloid leukemia (CML) therapy mostly arises from “off-target” effects on tyrosine kinase (TK) activity of wild type (wt) or mutated Bcr-Abl proteins which drive the disease resistance to imatinib (IM). We proved that the AK inhibitor MK-0457 induces the growth arrest DNA damage-inducible (Gadd) 45a through recruitment of octamer-binding (Oct)-1 transcription factor at a critical promoter region for gene transcription and covalent modifications of histone H3 (lysine 14 acetylation, lysine 9 de-methylation). Such epigenetic chromatin modifications may depict a general mechanism promoting the re-activation of tumor suppressor genes silenced by Bcr-Abl. [Copyright &y& Elsevier]

Abstract: Background: The Abbott RealTime High Risk HPV assay (ART) is an automated multiplex real-time PCR test for detection of DNA from 14 high risk (HR) HPV types in cervical specimens and simultaneous distinction of HPV16 and HPV18 from other HR-HPV. Objectives: To evaluate the performance of the ART assay in specimens referred for HPV testing to our laboratory (referral population) by comparison with historical data from HC2 and INNO-LiPA as well as histological status, if available. Study design: 412 cervical specimens were collected from women between 18 and 70 years of age: 301 previously tested by HC2 without clinical data and 111 previously tested by HC2 and INNO-LiPA with histological diagnosis of CIN3+. Results: Our study demonstrated good overall agreement between ART, HC2 and INNO-LiPA. In the group of the CIN3+ specimens HR-HPV was detected by ART in 93.07% (95% CI: 88.12–98.02), while HR-HPV detection rates with HC2 and INNO-LiPA were 91.09% (95% CI: 85.53–96.65) and 95.05% (95% CI: 90.82–99.28), respectively. The typing capability of ART for HPV16, HPV18 and a pool of twelve other HR-HPV types was investigated by comparison with INNO-LiPA demonstrating high overall assay concordance (89.81%; k 0.87). Conclusions: The Abbott RealTime assay showed similar clinical performance for detection of CIN3+ compared with HC2. The high level of automation and ability to identify HPV16, HPV18 and other HR-HPV make this assay a very attractive option for HR-HPV testing, potentially improving patient management by risk stratification of cytological abnormal populations. [Copyright &y& Elsevier]

Abstract: Background: Human papillomavirus (HPV) infection is a necessary event in the development of cervical carcinoma. High risk (HR) HPV genotypes, however, may progress differentially from low grade lesions to malignancy. Objectives: The necessity to genotype and quantify HPV-DNA in cervical screening programs, in the follow up post-surgical treatments and in monitoring the effectiveness of HPV vaccination programs, requires access to economical, high-throughput and flexible molecular technologies. Study design: A high-throughput two-step LNA real time PCR assay was developed consisting of real time PCR reactions with fluorescent Locked Nucleic Acid (LNA) probes. The first step permits classification into three prognostic-risk groups of nine HR HPV genotypes (16, 18, 31, 33, 35, 45, 52, 56 and 58) most frequently found associated with cervical lesions in Europe. The second step allows us to genotype/quantify the HPV-DNA only when clinical, epidemiological or prophylactic aims exist. Results: The specificity, repeatability, detection and quantitation limit, and linearity of the assay were evaluated and appear to be in agreement with guidelines for the validation of analytical procedures. The overall genotype concordance on cervical samples between our assay and INNOLiPA test was 94% (k 0.83) indicating good agreement. Conclusions: The two-step PCR assay can give much information relative to the predictive value of different HR HPV types and can quantify the genotype-specific viral load. In particular, its ability to detect and quantify nine HR HPV genotypes can help provide more efficient and successful patient care and may be useful for the monitoring of the efficacy of HPV vaccines. [Copyright &y& Elsevier]

This study investigates a novel multimodal treatment for chronic tinnitus, a condition that significantly affects quality of life, by combining personalized sound therapy with both low- and high-frequency electromagnetic wave stimulation. Conducted at Tor Vergata University Hospital in Rome, the research involved 55 patients and employed a portable medical device for therapy delivery. Treatment effectiveness was measured through the Tinnitus Functional Index (TFI), Tinnitus Handicap Inventory (THI), Visual Analogue Scale (VAS), Hyperacusis Questionnaire (HQ), and Short Form-36 Health Survey (SF-36), encompassing initial sound therapy and subsequent multimodal treatment phases. Remarkably, 73% of participants experienced notable improvements in TFI scores, with 39% reporting a significant enhancement of 13 points or more. This improvement was mirrored in secondary outcomes like THI, VAS, and HQ scores, along with certain SF-36 domains, indicating enhanced life quality and reduced tinnitus distress. The study underscored high compliance and no adverse effects, suggesting the combined therapy's promising potential in chronic tinnitus management. The findings advocate for further research to discern the distinct contributions of each treatment modality, positing that this innovative approach could ameliorate tinnitus symptoms and improve patient well-being, confirming its safety and efficacy. [ABSTRACT FROM AUTHOR]

The article informs about a study based on promoting the low expression of pro-apoptotic BCL2L11 gene associated with BCR-ABL1 fusion gene of chronic myeloid leukemia through DNA hypermethylation. It mentions that polymerase chain reaction and immunoprecipitation methods are used in the study. It adds that DNA methyltransferase (DNMT) 1 recruitment and 5 methylcytosine (5mC) excess was found to be involved in the aberrant DNA methylation at promoter-associated CpG islands of several genes.

The article presents a study which showed that the Aurora kinase (AK) c, MK-0457, induces chromatin covalent modifications that promote recruitment of transcriptional co-repressor heterochromatin protein (HP) 1 at a BCR promoter region critical for the fusion gene transcription. This study used the K562 cell line, murine bone marrowderived Ba/F3 cells stably transduced with BCR-ABL1 constructs coding.

Abstract: The presence of HPV 16 E1 and E2 genes was detected in cervical cytological samples using polymerase chain reaction assays. A total of 48 samples were analyzed from patients with HPV 16 infections associated with 13 low-grade cervical intraepithelial neoplasia and 35 high-grade cervical intraepithelial neoplasia. Disruption/deletion sites, within E1 and E2 genes, were detected using 6 primer pairs spanning the entire gene sequences. This technique is not able to recognize mixed DNA forms (integrated plus episomal DNA); therefore, it detects only the presence of pure integrated DNA. Both E1 and E2 genes were detected in 84.6% and in 62.9% of low and high-grade lesions, respectively. The rate of samples with disrupted/deleted genes was significantly higher in high-grade cervical intraepithelial neoplasia than in low-grade cervical intraepithelial neoplasia (P <0.05). In high-grade cervical intraepithelial neoplasia the disruption/deletion pattern involved both E1 and E2 genes and E2 gene was always involved, while in the low grade cervical intraepithelial neoplasia only E1 gene was involved. In conclusion, in high-grade cervical lesions E2 gene seems a suitable target to identify HPV 16 DNA integration into cellular genome. [Copyright &y& Elsevier]