University of Texas Southwestern Medical Center

About: University of Texas Southwestern Medical Center is a healthcare organization based out in Dallas, Texas, United States. It is known for research contribution in the topics: Population & Cancer. The organization has 39107 authors who have published 75242 publications receiving 4497256 citations. The organization is also known as: UT Southwestern & UT Southwestern Medical School.

Epigenetic Inactivation of RASSF1A in Lung and Breast Cancers and Malignant Phenotype Suppression

Abstract: Background: The recently identified RASSF1 locus is located within a 120-kilobase region of chromosome 3p21.3 that frequently undergoes allele loss in lung and breast cancers. We explored the hypothesis that RASSF1 encodes a tumor suppressor gene for lung and breast cancers. Methods: We assessed expression of two RASSF1 gene products, RASSF1A and RASSF1C, and the methylation status of their respective promoters in 27 non-small-cell lung cancer (NSCLC) cell lines, in 107 resected NSCLCs, in 47 small-cell lung cancer (SCLC) cell lines, in 22 breast cancer cell lines, in 39 resected breast cancers, in 104 nonmalignant lung samples, and in three breast and lung epithelial cultures. We also transfected a lung cancer cell line that lacks RASSF1A expression with vectors containing RASSF1A complementary DNA to determine whether exogenous expression of RASSF1A would affect in vitro growth and in vivo tumorigenicity of this cell line. All statistical tests were two-sided. Results: RASSF1A messenger RNA was expressed in nonmalignant epithelial cultures but not in 100% of the SCLC, in 65% of the NSCLC, or in 60% of the breast cancer lines. By contrast, RASSF1C was expressed in all nonmalignant cell cultures and in nearly all cancer cell lines. RASSF1A promoter hypermethylation was detected in 100% of SCLC, in 63% of NSCLC, in 64% of breast cancer lines, in 30% of primary NSCLCs, and in 49% of primary breast tumors but in none of the nonmalignant lung tissues. RASSF1A promoter hypermethylation in resected NSCLCs was associated with impaired patient survival (P = .046). Exogenous expression of RASSF1A in a cell line lacking expression decreased in vitro colony formation and in vivo tumorigenicity. Conclusion: RASSF1A is a potential tumor suppressor gene that undergoes epigenetic inactivation in lung and breast cancers through hypermethylation of its promoter region.

SynCAM, a Synaptic Adhesion Molecule That Drives Synapse Assembly

Abstract: Synapses, the junctions between nerve cells through which they communicate, are formed by the coordinated assembly and tight attachment of pre- and postsynaptic specializations. We now show that SynCAM is a brain-specific, immunoglobulin domain-containing protein that binds to intracellular PDZ-domain proteins and functions as a homophilic cell adhesion molecule at the synapse. Expression of the isolated cytoplasmic tail of SynCAM in neurons inhibited synapse assembly. Conversely, expression of full-length SynCAM in nonneuronal cells induced synapse formation by cocultured hippocampal neurons with normal release properties. Glutamatergic synaptic transmission was reconstituted in these nonneuronal cells by coexpressing glutamate receptors with SynCAM, which suggests that a single type of adhesion molecule and glutamate receptor are sufficient for a functional postsynaptic response.

An Analysis of Outcomes of Reconstruction or Amputation after Leg-Threatening Injuries

Abstract: Background Limb salvage for severe trauma has replaced amputation as the primary treatment in many trauma centers. However, long-term outcomes after limb reconstruction or amputation have not been fully evaluated. Methods We performed a multicenter, prospective, observational study to determine the functional outcomes of 569 patients with severe leg injuries resulting in reconstruction or amputation. The principal outcome measure was the Sickness Impact Profile, a multidimensional measure of self-reported health status (scores range from 0 to 100; scores for the general population average 2 to 3, and scores greater than 10 represent severe disability). Secondary outcomes included limb status and the presence or absence of major complications resulting in rehospitalization. Results At two years, there was no significant difference in scores for the Sickness Impact Profile between the amputation and reconstruction groups (12.6 vs. 11.8, P=0.53). After adjustment for the characteristics of the patients and t...