Cerebral white matter abnormalities associated with chromosome 18q duplication.

Background: Chromosome 18q duplications are associated with a range of phenotypes often similar to complete trisomy 18, variably including poor growth, feeding difficulties, congenital malformations and dysmorphic facial features. Although 18q duplication patients may have seizures and developmental impairment, brain MRI typically shows only variable degrees of cerebral atrophy.

Patient: We present a boy with a 52.

NR1D1 regulation by Ran GTPase via miR4472 identifies an essential vulnerability linked to aneuploidy in ovarian cancer.

While aneuploidy is a main enabling characteristic of cancers, it also creates specific vulnerabilities. Here we demonstrate that Ran inhibition targets epithelial ovarian cancer (EOC) survival through its characteristic aneuploidy. We show that induction of aneuploidy in rare diploid EOC cell lines or normal cells renders them highly dependent on Ran.

The double dealing of cyclin D1.

The cell cycle is tightly regulated by cyclins and their catalytic moieties, the cyclin-dependent kinases (CDKs). Cyclin D1, in association with CDK4/6, acts as a mitogenic sensor and integrates extracellular mitogenic signals and cell cycle progression. When deregulated (overexpressed, accumulated, inappropriately located), cyclin D1 becomes an oncogene and is recognized as a driver of solid tumors and hemopathies.

Cytoplasmic cyclin D1 controls the migration and invasiveness of mantle lymphoma cells.

Mantle cell lymphoma (MCL) is a hematologic neoplasm characterised by the t(11;14)(q13;q32) translocation leading to aberrant cyclin D1 expression. The cell functions of cyclin D1 depend on its partners and/or subcellular distribution, resulting in different oncogenic properties. We observed the accumulation of cyclin D1 in the cytoplasm of a subset of MCL cell lines and primary cells.

Cyclin D1 unbalances the redox status controlling cell adhesion, migration, and drug resistance in myeloma cells.

The interactions of multiple myeloma (MM) cells with their microenvironment are crucial for pathogenesis. MM cells could interact differentially with their microenvironment depending on the type of cyclin D they express. We established several clones that constitutively express cyclin D1 from the parental RPMI8226 MM cell line and analyzed the impact of cyclin D1 expression on cell behavior.

Necdin modulates proliferative cell survival of human cells in response to radiation-induced genotoxic stress.

Background: The finite replicative lifespan of cells, termed cellular senescence, has been proposed as a protective mechanism against the proliferation of oncogenically damaged cells, that fuel cancer. This concept is further supported by the induction of premature senescence, a process which is activated when an oncogene is expressed in normal primary cells as well as following intense genotoxic stresses. Thus, deregulation of genes that control this process, like the tumor suppressor p53, may contribute to promoting cancer by allowing cells to bypass senescence.

Cyclin D1 inhibits mitochondrial activity in B cells.

Cyclin D1 is a cell cycle regulatory protein that acts at the G1-S transition, following its binding to and activation by the cyclin-dependent kinases 4 or 6. Cyclin D1 is absent from the entire B-cell lineage but is present in a large percentage of 2 types of malignant B-cell hemopathy--mantle cell lymphoma and multiple myeloma--suggesting a major role of this protein in the malignancy process. We show here, in an experimental model of cyclin D1 fusion protein transduction in mature B cells, that, cyclin D1 inhibits total mitochondrial activity.

Cyclin D1 regulates p27(Kip1) stability in B cells.

p27(Kip1) is a cyclin-dependent kinase inhibitor that plays a critical role in regulating G(1)/S transition, and whose activity is, in part, regulated through interactions with D-type cyclins. We have generated the BD1-9 cell line, a BaF3 pro-B cells derivative in which cyclin D1 can be induced rapidly and reversibly by ponasterone A. The induction of cyclin D1 expression leads to a targeted p27(Kip1) accumulation in both cytoplasmic and nuclear compartments.

Cyclin K and cyclin D1b are oncogenic in myeloma cells.

Background: Aberrant expression of cyclin D1 is a common feature in multiple myeloma (MM) and always associated with mantle cell lymphoma (MCL). CCND1 gene is alternatively spliced to produce two cyclin D1 mRNA isoforms which are translated in two proteins: cyclin D1a and cyclin D1b. Both isoforms are present in MM cell lines and primary cells but their relative role in the tumorigenic process is still elusive.