The development of portal hypertension in a patient with cirrhosis portends a poor prognosis. Untreated or progressive portal hypertension has serious clinical outcomes, which are often fatal. It is important to recognize portal hypertension early to delay progression and to treat complications of portal hypertension as they arise.
View Article and Find Full Text PDFSporadic colorectal cancer (CRC) is a somatic genetic disease in which pathogenesis is influenced by the local colonic environment and the patient's genetic background. Consolidating the knowledge of genetic and epigenetic events that occur with initiation, progression, and metastasis of sporadic CRC has identified some biomarkers that might be utilized to predict behavior and prognosis beyond staging, and inform treatment approaches. Modern next-generation sequencing of sporadic CRCs has confirmed prior identified genetic alterations and has classified new alterations.
View Article and Find Full Text PDFThe majority of potent and broadly neutralizing antibodies against HIV-1 have been isolated from untreated patients with acute or chronic infection. To assess the extent of HIV-1 specific antibody response and neutralization after many years of virologic suppression from potent combination ART, we examined antibody binding titers and neutralization of 51 patients with chronic HIV-1 infection on suppressive ART for at least three years. In this cross-sectional analysis, we found high antibody titers against gp120, gp41, and the membrane proximal external region (MPER) in 59%, 43%, and 27% of patients, respectively.
View Article and Find Full Text PDFWhereas the presence of autoantibodies in cancer patients has been acknowledged, their diagnostic or therapeutic significance has yet to be established. This is due, at least in part, to the lack of robust screening techniques to detect and characterize such antibodies for further assessment. In this study, we screened colorectal cancer (CRC) patient sera for antibodies specifically targeting the key cell cycle inhibitory factor p21 encoded by the cyclin-dependent kinase inhibitor 1A (CDKN1A).
View Article and Find Full Text PDFHere, we report a case of a young man who presented with a significant upper gastrointestinal bleed treated by endoscopic removal of multiple hyperplastic polyps. Gastric hyperplastic polyps are a relatively uncommon cause of overt gastrointestinal bleeding. While most hyperplastic gastric polyps are asymptomatic, they may present with abdominal pain, iron deficiency anemia or gastric outlet obstruction.
View Article and Find Full Text PDFBackground And Objectives: Colorectal tumors are often observed with tumor infiltrating lymphocytes, presumably as a host-immune response, and patterns may segregate by types of genomic instability. Microsatellite unstable (MSI) colorectal cancers contain a pronounced lymphocyte reaction that can pathologically identify these tumors. Colorectal tumors with elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) have not been examined for lymphocyte patterns.
View Article and Find Full Text PDFMetastasis accounts for the majority of cancer-related deaths. Accurate prediction of metastatic potential of tumors has been elusive, and the search for clinically useful markers continues. We previously reported that GIV/Girdin triggers tumor cell migration by virtue of a C-terminal guanine-nucleotide exchange factor motif that activates Gαi.
View Article and Find Full Text PDFBackground & Aims: Elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) occurs during microsatellite instability (MSI) that is not associated with major defects in DNA mismatch repair (MMR) but rather the reduced (heterogenous) expression of the MMR protein hMSH3; it occurs in sporadic colorectal tumors. We examined the timing of development of EMAST during progression of colorectal neoplasias and looked for correlations between EMAST and clinical and pathology features of tumors.
Methods: We evaluated tumor samples from a cohort of patients that had 24 adenomas and 84 colorectal cancers.
Cells respond to growth factors by either migrating or proliferating, but not both at the same time, a phenomenon termed migration-proliferation dichotomy. The underlying mechanism of this phenomenon has remained unknown. We demonstrate here that Galpha(i) protein and GIV, its nonreceptor guanine nucleotide exchange factor (GEF), program EGF receptor (EGFR) signaling and orchestrate this dichotomy.
View Article and Find Full Text PDFBackground & Aims: DCC and UNC5C, Netrin-1 dependence receptors, perform an important role in intestinal epithelial biology. Both receptors frequently are down-regulated in colorectal cancer (CRC). Although CRCs frequently lose DCC owing to deletions at 18q, the mechanism for the UNC5C loss is poorly understood.
View Article and Find Full Text PDFBone morphogenetic proteins (BMPs) regulate cell differentiation, proliferation, and apoptosis through a canonical SMAD signaling cascade. Absence of BMP signaling causes the formation of intestinal juvenile polyps in the colon cancer-prone syndrome familial juvenile polyposis. As sporadic colon cancers appear to have intact BMP signaling, we evaluated if K-RAS, driving a mitogenic pathway frequently activated in colon cancer, negatively affects BMP growth suppression.
View Article and Find Full Text PDFBackground & Aims: Colon cancers with high-frequency microsatellite instability (MSI-H) develop frameshift mutations in tumor suppressors as part of their pathogenesis. ACVR2 is mutated at its exon 10 polyadenine tract in >80% of MSI-H colon cancers, coinciding with loss of protein. ACVR2 transmits the growth effects of activin via phosphorylation of SMAD proteins to affect gene transcription.
View Article and Find Full Text PDFAm J Physiol Gastrointest Liver Physiol
July 2006
Bone morphogenetic proteins (BMPs) are members of the transforming growth factor-beta superfamily, which utilize BMP receptors and intracellular SMADs to transduce their signals to regulate cell differentiation, proliferation, and apoptosis. Because mutations in BMP receptor type IA (BMPRIA) and SMAD4 are found in the germline of patients with the colon cancer predisposition syndrome juvenile polyposis, and because the contribution of BMP in colon cancers is largely unknown, we examined colon cancer cells and tissues for evidence of BMP signaling and determined its growth effects. We determined the presence and functionality of BMPR1A by examining BMP-induced phosphorylation and nuclear translocation of SMAD1; transcriptional activity via a BMP-specific luciferase reporter; and growth characteristics by cell cycle analysis, cell growth, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide metabolic assays.
View Article and Find Full Text PDF