Chondroitin sulfates play a major role in breast cancer metastasis: a role for CSPG4 and CHST11 gene expression in forming surface P-selectin ligands in aggressive breast cancer cells.

INTRODUCTION: We have previously demonstrated that chondroitin sulfate glycosaminoglycans (CS-GAGs) on breast cancer cells function as P-selectin ligands. This study was performed to identify the carrier proteoglycan (PG) and the sulfotransferase gene involved in synthesis of the surface P-selectin-reactive CS-GAGs in human breast cancer cells with high metastatic capacity, as well as to determine a direct role for CS-GAGs in metastatic spread. METHODS: Quantitative real-time PCR (qRT-PCR) and flow cytometry assays were used to detect the expression of genes involved in the sulfation and presentation of chondroitin in several human breast cancer cell lines. Transient transfection of the human breast cancer cell line MDA-MB-231 with the siRNAs for carbohydrate (chondroitin 4) sulfotransferase-11 (CHST11) and chondroitin sulfate proteoglycan 4 (CSPG4 ) was used to investigate the involvement of these genes in expression of surface P-selectin ligands. The expression of CSPG4 and CHST11 in 15 primary invasive breast cancer clinical specimens was assessed by qRT-PCR. The role of CS-GAGs in metastasis was tested using the 4T1 murine mammary cell line (10 mice per group). RESULTS: The CHST11 gene was highly expressed in aggressive breast cancer cells but significantly less so in less aggressive breast cancer cell lines. A positive correlation was observed between the expression levels of CHST11 and P-selectin binding to cells (P < 0.0001). Blocking the expression of CHST11 with siRNA inhibited CS-A expression and P-selectin binding to MDA-MB-231 cells. The carrier proteoglycan CSPG4 was highly expressed on the aggressive breast cancer cell lines and contributed to the P-selectin binding and CS-A expression. In addition, CSPG4 and CHST11 were over-expressed in tumor-containing clinical tissue specimens compared with normal tissues. Enzymatic removal of tumor-cell surface CS-GAGs significantly inhibited lung colonization of the 4T1 murine mammary cell line (P = 0.0002). CONCLUSIONS: Cell surface P-selectin binding depends on CHST11 gene expression. CSPG4 serves as a P-selectin ligand through its CS chain and participates in P-selectin binding to the highly metastatic breast cancer cells. Removal of CS-GAGs greatly reduces metastatic lung colonization by 4T1 cells. The data strongly indicate that CS-GAGs and their biosynthetic pathways are promising targets for the development of anti-metastatic therapies.

A Pilot Dental Survey on Maui.

Routine dental screening surveys of third graders have proven to be a useful tool to monitor the dental health of a community, especially those of highest risk. In 2010 the PEW Charitable Trust (PEW) conducted state-by-state oral hygiene assessments, giving Hawai'i a poor grade, with routine dental surveys of children one of several criteria not met. The Maui Oral Health Task Force piloted its own survey for the island of Maui to assess the challenges in implementing a dental screening and to gain an understanding as to how obstacles might be addressed. Three issues were identified: technical (sampling methodology, data interpretation, and analysis), administrative (approvals of protocols, consent forms, and confidentiality), and operational (participation rates, dental referrals, and missing data of socio-economic status). These issues were relatively easy to resolve over the course of a few months due to the public's and providers' outcry over the negative findings of the PEW report. Two hundred and eighty-one students were surveyed, which represents 46% of the children whose forms were sent home for parental consent and approval. Of those returning the forms, 77% had parent's consent to participate. Based on our island survey, the estimated sample size and participation rate for the State of Hawai'i would be comparable to those of other states, which had met the PEW survey criteria. Comparative exploratory analysis between Maui and survey data from other states underscores the value of prevention in averting dental treatment.