Case-Control Study for 23 Cancer Types With Functional Analysis of : Risk Estimation and Clinical Recommendations in East Asia.

Purpose: is the frequently detected cancer-predisposing gene in female breast cancer. In addition, the association with the risks of other cancer types has been suggested, and clinical management has also been discussed. Although clinical relevance of germline variants differs across population, there is little evidence of the clinical relevance of germline variants in East Asia.

In-frame germline TP53 variant impairs p53 oligomerization and predisposes to cancer.

Germline loss-of-function variants in TP53 cause Li-Fraumeni syndrome (LFS) characterized by an early onset of various cancer types including sarcomas, adrenocortical carcinoma, and breast cancer. The most common are mutations in the DNA binding domain of p53, but alterations in the oligomerization domain also cause LFS with variable level of penetrance. Here we report identification of a novel germline in-frame deletion TP53 variant c.

An ATM-PPM1D Circuit Controls the Processing and Restart of DNA Replication Forks.

In response to DNA replication stress, DNA damage signaling kinases inhibit origin firing and promote the remodeling and stabilization of replication forks, leading to a systemic reduction in DNA synthesis that protects genomic integrity. Little is understood about the regulatory mechanisms of replication stress recovery, including the mechanisms involved in the restart of stalled replication forks. Here, we identify the oncogenic phosphatase PPM1D/WIP1 as a critical regulator of replication fork restart.

Protein structure and interactions elucidated with in-cell NMR for different cell cycle phases and in 3D human tissue models.

Most of our knowledge of protein structure and function originates from experiments performed with purified proteins resuspended in dilute, buffered solutions. However, most proteins function in crowded intracellular environments with complex compositions. Significant efforts have been made to develop tools to study proteins in their native cellular settings.

PPM1D activity promotes cellular transformation by preventing senescence and cell death.

Cell cycle checkpoints, oncogene-induced senescence and programmed cell death represent intrinsic barriers to tumorigenesis. Protein phosphatase magnesium-dependent 1 (PPM1D) is a negative regulator of the tumour suppressor p53 and has been implicated in termination of the DNA damage response. Here, we addressed the consequences of increased PPM1D activity resulting from the gain-of-function truncating mutations in exon 6 of the PPM1D.

FAM110A promotes mitotic spindle formation by linking microtubules with actin cytoskeleton.

Precise segregation of chromosomes during mitosis requires assembly of a bipolar mitotic spindle followed by correct attachment of microtubules to the kinetochores. This highly spatiotemporally organized process is controlled by various mitotic kinases and molecular motors. We have recently shown that Casein Kinase 1 (CK1) promotes timely progression through mitosis by phosphorylating FAM110A leading to its enrichment at spindle poles.

RAD18 directs DNA double-strand break repair by homologous recombination to post-replicative chromatin.

RAD18 is an E3 ubiquitin ligase that prevents replication fork collapse by promoting DNA translesion synthesis and template switching. Besides this classical role, RAD18 has been implicated in homologous recombination; however, this function is incompletely understood. Here, we show that RAD18 is recruited to DNA lesions by monoubiquitination of histone H2A at K15 and counteracts accumulation of 53BP1.

Ppm1d truncating mutations promote the development of genotoxic stress-induced AML.

Hematopoietic stem cells (HSCs) ensure blood cell production during the life-time of an organism, and to do so they need to balance self-renewal, proliferation, differentiation, and migration in a steady state as well as in response to stress or injury. Importantly, aberrant proliferation of HSCs leads to hematological malignancies, and thus, tight regulation by various tumor suppressor pathways, including p53, is essential. Protein phosphatase magnesium-dependent 1 delta (PPM1D) is a negative regulator of p53 and promotes cell survival upon induction of genotoxic stress.

ENIGMA CHEK2gether Project: A Comprehensive Study Identifies Functionally Impaired CHEK2 Germline Missense Variants Associated with Increased Breast Cancer Risk.

Purpose: Germline pathogenic variants in CHEK2 confer moderately elevated breast cancer risk (odds ratio, OR ∼ 2.5), qualifying carriers for enhanced breast cancer screening. Besides pathogenic variants, dozens of missense CHEK2 variants of uncertain significance (VUS) have been identified, hampering the clinical utility of germline genetic testing (GGT).

PPM1D activity promotes the replication stress caused by cyclin E1 overexpression.

Oncogene-induced replication stress has been recognized as a major cause of genome instability in cancer cells. Increased expression of cyclin E1 caused by amplification of the CCNE1 gene is a common cause of replication stress in various cancers. Protein phosphatase magnesium-dependent 1 delta (PPM1D) is a negative regulator of p53 and has been implicated in termination of the cell cycle checkpoint.

Importance of Germline and Somatic Alterations in Human , , and Genes Coding for MRN Complex.

The , , and genes encode for the nuclear MRN protein complex, which senses the DNA double strand breaks and initiates the DNA repair. The MRN complex also participates in the activation of ATM kinase, which coordinates DNA repair with the p53-dependent cell cycle checkpoint arrest. Carriers of homozygous germline pathogenic variants in the MRN complex genes or compound heterozygotes develop phenotypically distinct rare autosomal recessive syndromes characterized by chromosomal instability and neurological symptoms.

Phosphorylation of TRF2 promotes its interaction with TIN2 and regulates DNA damage response at telomeres.

Protein phosphatase magnesium-dependent 1 delta (PPM1D) terminates the cell cycle checkpoint by dephosphorylating the tumour suppressor protein p53. By targeting additional substrates at chromatin, PPM1D contributes to the control of DNA damage response and DNA repair. Using proximity biotinylation followed by proteomic analysis, we identified a novel interaction between PPM1D and the shelterin complex that protects telomeric DNA.

Many Ways to the Cell Cycle Exit after Inhibition of CDK4/6.

Cyclin-dependent kinases (CDKs) are master regulators of proliferation, and therefore they represent attractive targets for cancer therapy. Deve-lopment of selective CDK4/6 inhibitors including palbociclib revolutionized the treatment of advanced HR+/HER2- breast cancer. Inhibition of CDK4/6 leads to cell cycle arrest in G0/G1 phase and eventually to a permanent cell cycle exit called senescence.

CDC25B is required for the metaphase I-metaphase II transition in mouse oocytes.

Mammalian oocytes are arrested at meiotic prophase I. The dual-specificity phosphatase CDC25B is essential for cyclin-dependent kinase 1 (CDK1) activation that drives resumption of meiosis. CDC25B reverses the inhibitory effect of the protein kinases WEE1 and MYT1 on CDK1 activation.

C53 Interacting with UFM1-Protein Ligase 1 Regulates Microtubule Nucleation in Response to ER Stress.

ER distribution depends on microtubules, and ER homeostasis disturbance activates the unfolded protein response resulting in ER remodeling. CDK5RAP3 (C53) implicated in various signaling pathways interacts with UFM1-protein ligase 1 (UFL1), which mediates the ufmylation of proteins in response to ER stress. Here we find that UFL1 and C53 associate with γ-tubulin ring complex proteins.

CK1-mediated phosphorylation of FAM110A promotes its interaction with mitotic spindle and controls chromosomal alignment.

Progression through the cell cycle is driven by cyclin-dependent kinases that control gene expression, orchestration of mitotic spindle, and cell division. To identify new regulators of the cell cycle, we performed transcriptomic analysis of human non-transformed cells expressing a fluorescent ubiquitination-based cell cycle indicator and identified 701 transcripts differentially expressed in G1 and G2 cells. Family with sequence similarity 110 member A (FAM110A) protein is highly expressed in G2 cells and localized at mitotic spindle and spindle poles during mitosis.

A novel assay for screening WIP1 phosphatase substrates in nuclear extracts.

Upon exposure to genotoxic stress, cells activate DNA damage response (DDR) that coordinates DNA repair with a temporal arrest in the cell cycle progression. DDR is triggered by activation of ataxia telangiectasia mutated/ataxia telangiectasia and Rad3-related protein kinases that phosphorylate multiple targets including tumor suppressor protein tumor suppressor p53 (p53). In addition, DNA damage can activate parallel stress response pathways [such as mitogen-activated protein kinase p38 alpha (p38)/MAPK-activated protein kinase 2 (MK2) kinases] contributing to establishing the cell cycle arrest.

Cyclin A2 localises in the cytoplasm at the S/G2 transition to activate PLK1.

Cyclin A2 is a key regulator of the cell cycle, implicated both in DNA replication and mitotic entry. Cyclin A2 participates in feedback loops that activate mitotic kinases in G2 phase, but why active Cyclin A2-CDK2 during the S phase does not trigger mitotic kinase activation remains unclear. Here, we describe a change in localisation of Cyclin A2 from being only nuclear to both nuclear and cytoplasmic at the S/G2 border.

Germline Variants in Cancer Predisposition: Stalemate Rather than Checkmate.

Germline alterations in many genes coding for proteins regulating DNA repair and DNA damage response (DDR) to DNA double-strand breaks (DDSB) have been recognized as pathogenic factors in hereditary cancer predisposition. The ATM-CHEK2-p53 axis has been documented as a backbone for DDR and hypothesized as a barrier against cancer initiation. However, although CHK2 kinase coded by the gene expedites the DDR signal, its function in activation of p53-dependent cell cycle arrest is dispensable.

Identification of Germline Mutations in Melanoma Patients with Early Onset, Double Primary Tumors, or Family Cancer History by NGS Analysis of 217 Genes.

Cutaneous melanoma is the deadliest skin malignity with a rising prevalence worldwide. Patients carrying germline mutations in melanoma-susceptibility genes face an increased risk of melanoma and other cancers. To assess the spectrum of germline variants, we analyzed 264 Czech melanoma patients indicated for testing due to early melanoma (at <25 years) or the presence of multiple primary melanoma/melanoma and other cancer in their personal and/or family history.

Truncated PPM1D Prevents Apoptosis in the Murine Thymus and Promotes Ionizing Radiation-Induced Lymphoma.

Genome integrity is protected by the cell-cycle checkpoints that prevent cell proliferation in the presence of DNA damage and allow time for DNA repair. The transient checkpoint arrest together with cellular senescence represent an intrinsic barrier to tumorigenesis. Tumor suppressor p53 is an integral part of the checkpoints and its inactivating mutations promote cancer growth.

Phosphorylation of PLK3 Is Controlled by Protein Phosphatase 6.

Polo-like kinases play essential roles in cell cycle control and mitosis. In contrast to other members of this kinase family, PLK3 has been reported to be activated upon cellular stress including DNA damage, hypoxia and osmotic stress. Here we knocked out in human non-transformed RPE cells using CRISPR/Cas9-mediated gene editing.

Multigene Panel Germline Testing of 1333 Czech Patients with Ovarian Cancer.

Ovarian cancer (OC) is the deadliest gynecologic malignancy with a substantial proportion of hereditary cases and a frequent association with breast cancer (BC). Genetic testing facilitates treatment and preventive strategies reducing OC mortality in mutation carriers. However, the prevalence of germline mutations varies among populations and many rarely mutated OC predisposition genes remain to be identified.