Chromatin extrusion explains key features of loop and domain formation in wild-type and engineered genomes.

We recently used in situ Hi-C to create kilobase-resolution 3D maps of mammalian genomes. Here, we combine these maps with new Hi-C, microscopy, and genome-editing experiments to study the physical structure of chromatin fibers, domains, and loops. We find that the observed contact domains are inconsistent with the equilibrium state for an ordinary condensed polymer.

Transcription factor YY1 expression in human gastrointestinal cancer cells.

Over-expression of the multifunctional zinc-finger transcription factor Yin Yang 1 (YY1) has been associated with cellular proliferation and resistance to apoptotic stimuli. In this study, we report that YY1 was uniformly highly over-expressed in a wide range of human cancer cell lines and in human colon cancer tissue samples. The examination of YY1-specific mRNA expression demonstrated at least six mRNA isoforms ubiquitously expressed in normal human adult and fetal tissues.

Deregulated Aurora-B induced tetraploidy promotes tumorigenesis.

High expression of Aurora-B has been observed in various cancers, and inhibition of this kinase has been shown to halt cellular proliferation. However, the mechanism of effect of Aurora-B on cellular transformation has not been fully explored. Here, we show that overexpression of Aurora-B in murine epithelial cells promotes generation of tetraploids.

hBub1 deficiency triggers a novel p53 mediated early apoptotic checkpoint pathway in mitotic spindle damaged cells.

It has been universally believed that spindle assembly checkpoint (SAC) proteins which include the kinetochore proteins are involved in monitoring the faithful segregation of sister chromatids during cell division and hence defects in these proteins result in aneuploidy. Furthermore, there are multiple sources of experimental data to suggest that a defect in p53 can also promote genomic instability leading to aneuploidy. Despite these observations, a molecular basis for the prevention of aneuploidy to maintain genomic integrity upon activation of SAC has largely remained elusive.

Human gastrin-releasing peptide receptor gene regulation requires transcription factor binding at two distinct CRE sites.

Ectopic expression of the gastrin-releasing peptide (GRP) receptor (GRP-R) occurs frequently in human malignancies of the gastrointestinal tract. Owing to paracrine and autocrine interaction with its specific high-affinity ligand GRP, tumor cell proliferation, migration, and invasion might ensue. Here we provide the first insights regarding molecular mechanisms of GRP-R regulation in gastrointestinal cancer cells.

Fat depot-specific characteristics are retained in strains derived from single human preadipocytes.

Fat depots vary in size, function, and potential contribution to disease. Since fat tissue turns over throughout life, preadipocyte characteristics could contribute to this regional variation. To address whether preadipocytes from different depots are distinct, we produced preadipocyte strains from single abdominal subcutaneous, mesenteric, and omental human preadipocytes by stably expressing human telomere reverse transcriptase (hTERT).

Bombesin regulates cyclin D1 expression through the early growth response protein Egr-1 in prostate cancer cells.

Our previous studies indicate that the activation of mitogen-activated protein kinase (MAPK) pathway is involved in bombesin-induced cell proliferation in prostate cancer cells. Cyclin D1 is a critical regulator involved in cell cycle progression through the G1 phase into the S phase, thereby contributing to cell proliferation. Mostly, mitogen-stimulated expression of cyclin D1 is attributed to the extracellular signal-regulated kinase (ERK) activation.

Mechanism of Aurora-B degradation and its dependency on intact KEN and A-boxes: identification of an aneuploidy-promoting property.

The kinase Aurora-B, a regulator of chromosome segregation and cytokinesis, is highly expressed in a variety of tumors. During the cell cycle, the level of this protein is tightly controlled, and its deregulated abundance is suspected to contribute to aneuploidy. Here, we provide evidence that Aurora-B is a short-lived protein degraded by the proteasome via the anaphase-promoting cyclosome complex (APC/c) pathway.

Differential DNA hypermethylation of critical genes mediates the stage-specific tobacco smoke-induced neoplastic progression of lung cancer.

Promoter DNA methylation status of six genes in samples derived from 27 bronchial epithelial cells and matching blood samples from 22 former/current smokers and five nonsmokers as well as 49 primary non-small cell lung cancer samples with corresponding blood controls was determined using methylation-specific PCR (MSP). Lung tumor tissues showed a significantly higher frequency of promoter DNA methylation in p16, MGMT, and DAPK (P < 0.05; Fisher's exact test).

Abundance of two human preadipocyte subtypes with distinct capacities for replication, adipogenesis, and apoptosis varies among fat depots.

Fat depots vary in function and size. The preadipocytes that fat cells develop from exhibit distinct regional characteristics that persist in culture. Human abdominal subcutaneous cultured preadipocytes undergo more extensive lipid accumulation, higher adipogenic transcription factor expression, and less TNF-alpha-induced apoptosis than omental preadipocytes.