hymecromone and Carcinoma

Numerous studies have demonstrated the importance of altered hyaluronan metabolism to malignant progression of multiple tumor types, including breast carcinomas. Increased hyaluronan (HA) metabolism in the stroma of primary tumors promotes activation of oncogenic signaling pathways that impact tumor initiation, growth, and invasion. Carcinoma cell synthesis and assembly of HA-rich pericellular matrices induces a stromal-independent phenotype, which is associated with cancer progression. Although the pro-tumorigenic role of stromal HA is well established, a novel but unexplored hypothesis is that carcinoma cell-associated HA pericellular matrices promote metastasis of circulating tumor cells. Here, we report the development of an in vitro assay that employs microfluidic techniques to directly measure the importance of an HA-rich pericellular matrix in the entry of carcinoma cells into ectopic sites. This model provides the capability to visualize specific steps in metastasis, which is difficult using animal models. The results show that the presence of a HA-rich pericellular matrix correlates to the invasive and metastatic potential of breast carcinoma cells. Furthermore, enzymatic removal or pharmacologic inhibition of HA synthesis significantly inhibits carcinoma cell extravasation and invasion in this model system. These results implicate pericellular HA-rich carcinoma cell associated pericellular matrices in colonization of ectopic sites by circulating tumor cells and support specific targeting of this matrix to limit metastasis in patients.

Topics: Animals; Breast Neoplasms; Carcinoma; Cell Adhesion; Cell Line, Tumor; Cell Movement; Extracellular Matrix; Female; Green Fluorescent Proteins; Human Umbilical Vein Endothelial Cells; Humans; Hyaluronic Acid; Hymecromone; Mice; Mice, Nude; Microfluidics; Neoplasm Invasiveness; Neoplasm Metastasis; Phenotype

4-Methylumbelliferone (4-MU), a hyaluronan (HA) synthesis inhibitor, has antitumor activity in cancer cells. However, few studies have focused on its effects on ovarian cancer. The aim of this study was to investigate the effects of 4-MU on ovarian cancer and to elucidate its mechanism of action.. The HRA human ovarian serous adenocarcinoma cell line was used in this study. The effects of 4-MU on cell proliferation, migration, and invasion were determined by using in vitro assays as well as an in vivo rat peritoneal carcinomatosis model. The expression of HA synthase (HAS), CD44 HA receptor, vascular endothelial growth factor (VEGF), and thymidine phosphorylase (TP) mRNA in HRA cells was analyzed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR).. 4-MU administration inhibited the growth of peritoneal tumors and significantly prolonged survival. In vitro experiments showed that 4-MU inhibited HRA cell proliferation in a dose-dependent manner, while it did not affect HRA cell invasion and migration. 4-MU significantly decreased TP mRNA expression in HRA cells. On the other hand, since HAS2, CD44, and VEGF endogenous mRNA expression levels were very low in HRA cells, it was impossible to evaluate the effect of 4-MU treatment.. These results suggest that 4-MU exerts its antitumor effect on ovarian cancer through suppressing TP expression.

Topics: Animals; Antineoplastic Agents; Carcinoma; Cell Line, Tumor; Cell Movement; Cell Proliferation; Female; Gene Expression Regulation, Neoplastic; Humans; Hymecromone; Neoplasm Invasiveness; Ovarian Neoplasms; Rats, Nude; Thymidine Phosphorylase; Xenograft Model Antitumor Assays