ABSTRACT
Hyaluronan (HA) and hyaluronan synthases (HAS) have been implicated in cancer growth and progression. We previously have shown that HAS3 and HA mediate tumor growth in SW620 colon cancer cells, but the mechanism remains poorly understood. In addition, the effect of HAS3 inhibition on tumor growth with other cells lines has not been explored. We therefore hypothesized that inhibition of HAS3 in highly tumorigenic HCT116 colon cancer cells would decrease tumor growth and that the underlying mechanism would involve altering proliferation and/or apoptosis. HAS3 expression was inhibited by transfection with siRNA; a scrambled sequence served as a control. Stable transfectants were injected into the flanks of nude mice and tumor growth followed for 30 days. Proliferation and apoptosis were then assessed in the harvested tumors. Results were compared using the Students' t-test and ANOVA where appropriate. siRNA transfection decreased HAS3 expression, protein production, and pericellular HA retention, and decreased in vivo tumor growth. Proliferation was unaffected in the HCT116 tumors, but increased slightly in the SW620 tumors. In contrast, HAS3 inhibition significantly increased apoptosis in all tumors. HAS3 inhibition decreases subcutaneous tumor growth by colon cancer cells and significantly increases apoptosis with less effect on proliferation. These data show that HAS3 and HA mediate colon cancer growth by inhibiting apoptosis.
Subject(s)
Apoptosis , Biomarkers, Tumor/metabolism , Colonic Neoplasms/genetics , Glucuronosyltransferase/antagonists & inhibitors , Hyaluronic Acid/metabolism , RNA, Small Interfering/genetics , Animals , Biomarkers, Tumor/genetics , Caspase 3/genetics , Caspase 3/metabolism , Cell Proliferation , Colonic Neoplasms/enzymology , Colonic Neoplasms/pathology , Glucuronosyltransferase/genetics , Glucuronosyltransferase/metabolism , HCT116 Cells , Humans , Hyaluronan Synthases , Injections, Subcutaneous , Ki-67 Antigen/genetics , Ki-67 Antigen/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Nude , RNA, Small Interfering/metabolism , Transfection , Tumor Burden , Xenograft Model Antitumor AssaysABSTRACT
Internal hernias are an uncommon cause of bowel obstruction, accounting for less than 1% of cases. Paraduodenal hernias, the most common type of internal hernias, are believed to be congenital in origin. They can be asymptomatic, cause chronic abdominal pain, or present with acute intestinal obstruction with strangulation and ischemia. We describe a case of left paraduodenal hernia found in a patient who presented with acute intestinal obstruction.
