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Abstract: Preclinical data suggest a rationale for combining CPX-351, a dual-drug liposomal encapsulation of daunorubicin and cytarabine, with venetoclax, a B-cell lymphoma-2 inhibitor. This phase 1b study evaluated lower-intensity CPX-351 combined with venetoclax in adults with acute myeloid leukemia (AML) considered unfit/ineligible for intensive chemotherapy. In a dose-exploration phase using a 3+3 design, patients received stepwise dosing of CPX-351 IV on days 1 and 3 plus venetoclax 400 mg orally on days 2 to 21 per cycle to determine the recommended phase 2 dose (RP2D) for this combination. During the expansion phase, additional patients received CPX-351 plus venetoclax at the identified RP2D. The primary end points were the RP2D and safety of CPX-351 combined with venetoclax. Secondary end points included preliminary efficacy and pharmacokinetics. Overall, 35 patients were enrolled in the study. A RP2D of CPX-351 30 units/m2 (daunorubicin 13.2 mg/m2 and cytarabine 30 mg/m2) plus venetoclax 400 mg was established. The safety profile of the combination was consistent with the known safety profiles of CPX-351 and venetoclax. Complete remission (CR)/CR with incomplete hematologic recovery (CRi) was achieved by 17 of 35 patients (49%), all after cycle 1; of these, 14 were negative for measurable residual disease. CR was achieved by 1 of 8 patients (13%) with a mutation in TP53, and CR/CRi was achieved by 15 of 26 patients (58%) with wild-type TP53. This study highlights that lower-intensity therapy of CPX-351 plus venetoclax as induction therapy provides a well-tolerated treatment option in adults with AML deemed unfit for intensive chemotherapy. This trial was registered at www.ClinicalTrials.gov as #NCT04038437., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Objectives: Children with cancer are exposed to repeated painful and invasive procedures. This study examines Chinese parents' stress and perception toward their children's procedural pain control., Methods: We recruited 265 parents of children (aged <18 years) diagnosed with hematological cancer (74.7%) and solid tumors (25.3%) from two major public hospitals. Parents used a scale (0-10) to rate perceived pain experienced by their child when undergoing lumbar puncture (LP), bone marrow aspirate, or/and biopsy. They reported their stress level and attitudes toward analgesics using the adapted Pain Flexibility Scale for Parents and Parental Medication Attitude Questionnaire. General linear modeling was used to identify factors associated with perception outcomes., Results: Parents (72.8% mothers, age 36.5 [6.8] years) expressed that they were worried (31.7%) and had difficulty with concentration (57.7%) when the child was in pain. Among parents whose children had undergone LP (n = 207), 39.1% perceived that their child still experienced severe pain (pain score >7) even with existing pain control measures. Parents reported concerns over side effects of analgesics (69.4%) and addiction (35.1%). Half of the parents (47.2%) perceived that analgesics should only be reserved for severe pain. Parents who were older (estimate = 2.07, SE = 0.87; P = 0.0054) and had lower education attainment (estimate = -3.38, SE = 1.09; P = 0.0021) had a more negative attitude toward analgesics use. Higher parental distress was associated with avoidance of analgesics use (r s  = 0.17, P = 0.0052)., Conclusion: Our findings suggested that subgroups of Chinese parents demonstrated distress with their child's pain and harbored misconceptions over analgesics use. Future work includes devising targeted psychoeducation interventions for these parents., (Copyright © 2020 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.)

BRCA1 C-terminal domains are found in a specialized group of 23 proteins that function in the DNA damage response to protect genomic integrity. C-terminal domain phosphatase 1 (CTDP1) is the only phosphatase with a BRCA1 C-terminal domain in the human proteome, yet direct participation in the DNA damage response has not been reported. Examination of the CTDP1 BRCA1 C-terminal domain-specific protein interaction network revealed 103 high confidence interactions enriched in DNA damage response proteins, including FANCA and FANCI that are central to the Fanconi anemia DNA repair pathway necessary for the resolution of DNA interstrand crosslink damage. CTDP1 expression promotes DNA damage-induced FANCA and FANCD2 foci formation and enhances homologous recombination repair efficiency. CTDP1 was found to regulate multiple aspects of FANCI activity, including chromatin localization, interaction with γ-H2AX, and SQ motif phosphorylations. Knockdown of CTDP1 increases MCF-10A sensitivity to DNA interstrand crosslinks and double-strand breaks, but not ultraviolet radiation. In addition, CTDP1 knockdown impairs in vitro and in vivo growth of breast cancer cell lines. These results elucidate the molecular functions of CTDP1 in Fanconi anemia interstrand crosslink repair and identify this protein as a potential target for breast cancer therapy., Competing Interests: Conflict of interestThe authors declare that they have no conflict of interest.

Fanconi anemia (FA), the most common form of inherited bone marrow failure, predisposes to leukemia and solid tumors. FA is caused by the genetic disruption of a cellular pathway that repairs DNA interstrand crosslinks. The impaired function of this pathway, and the genetic instability that results, is considered the main pathogenic mechanism behind this disease. The identification of breast cancer susceptibility genes (for example, BRCA1/FANCS and BRCA2/FANCD1) as being major players in the FA pathway has led to a surge in molecular studies, resulting in the concept of the FA-BRCA pathway. In this review, we discuss recent advances in the molecular pathogenesis of FA from three viewpoints: (a) new FA genes, (b) modifier pathways that influence the cellular and clinical phenotypes of FA and (c) non-canonical functions of FA genes that may drive disease progression independently of deficient DNA repair. Potential therapeutic approaches for FA that are relevant to each will also be proposed.

Repair of interstrand crosslinks by the Fanconi anemia (FA) pathway requires both monoubiquitination and de-ubiquitination of the FANCI/FANCD2 (FANCI/D2) complex. In the standing model, the phosphorylation of six sites in the FANCI S/TQ cluster domain occurs upstream of, and promotes, FANCI/D2 monoubiquitination. We generated phospho-specific antibodies against three different S/TQ cluster sites (serines 556, 559, and 565) on human FANCI and found that, in contrast to the standing model, distinct FANCI sites were phosphorylated either predominantly upstream (ubiquitination independent; serine 556) or downstream (ubiquitination-linked; serines 559 and 565) of FANCI/D2 monoubiquitination. Ubiquitination-linked FANCI phosphorylation inhibited FANCD2 de-ubiquitination and bypassed the need to de-ubiquitinate FANCD2 to achieve effective interstrand crosslink repair. USP1 depletion suppressed ubiquitination-linked FANCI phosphorylation despite increasing FANCI/D2 monoubiquitination, providing an explanation of why FANCD2 de-ubiquitination is important for function of the FA pathway. Our work results in a refined model of how FANCI phosphorylation activates the FANCI/D2 complex., (Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.)

The Fanconi anemia (FA)-BRCA pathway mediates repair of DNA interstrand crosslinks. The FA core complex, a multi-subunit ubiquitin ligase, participates in the detection of DNA lesions and monoubiquitinates two downstream FA proteins, FANCD2 and FANCI (or the ID complex). However, the regulation of the FA core complex itself is poorly understood. Here we show that the FA core complex proteins are recruited to sites of DNA damage and form nuclear foci in S and G2 phases of the cell cycle. ATR kinase activity, an intact FA core complex and FANCM-FAAP24 were crucial for this recruitment. Surprisingly, FANCI, but not its partner FANCD2, was needed for efficient FA core complex foci formation. Monoubiquitination or ATR-dependent phosphorylation of FANCI were not required for the FA core complex recruitment, but FANCI deubiquitination by USP1 was. Additionally, BRCA1 was required for efficient FA core complex foci formation. These findings indicate that FANCI functions upstream of FA core complex recruitment independently of FANCD2, and alter the current view of the FA-BRCA pathway.

The MYC oncogene induces both cell proliferation and apoptosis. The apoptotic function of MYC is thought to inhibit carcinogenesis; thus, when disrupted, tumorigenic potential is increased. Both MYC and transforming growth factor alpha (TGFalpha) are commonly over-expressed in hepatocellular carcinomas, and transgenic mice expressing these genes rapidly develop tumors via the suppression of MYC-induced apoptosis by the growth factor. However, the nature of the interactions between MYC and TGFalpha are not well understood. Specifically, it is unclear whether TGFalpha acts only as an anti-apoptotic factor in its interactions with MYC or whether it has substantial effects on cell growth. We investigated whether TGFalpha can provide additional mitogenic signals if it is not required to act as an anti-apoptotic factor. We demonstrate that expression of MYC and TGFalpha in liver progenitor cells (known as oval cells) results in enhanced cell proliferation in culture and the generation of poorly differentiated tumors after inoculation into nude mice. We further demonstrate that while the apoptosis-deficient T58A and S71F alleles of MYC retain their ability to promote oval cell proliferation, they have opposite growth interactions with TGFalpha. The T58A allele has a stimulatory effect on both proliferation and tumorigenicity. In contrast, co-expression of the S71F allele reduces proliferation and slows tumor development. We conclude that the tumorigenic growth effects of MYC in TGFalpha-expressing liver progenitor cells are not solely dependent on its apoptotic activity.