Extracellular Sulfatases As Novel Biomarkers For Early Detection of Cancer

University Of California, San Francisco, San Francisco CA

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Abstract

DESCRIPTION (provided by applicant): Among all cancers, non-small cell lung cancer (NSCLC) and glioblastoma (the most common and most malignant type of astrocytic brain cancer) are two of the most deadly cancers with survival measured in months. Earlier diagnosis using a robust biomarker would likely improve survival. However, currently no such biomarker exists due to the heterogeneity of the diseases and the lack of biomarkers with functional relevance in tumorigenesis. The extracellular heparan sulfate endosulfatases, SULF1 and SULF2, are overexpressed in a wide variety of human cancers, and SULF2, in particular, has been shown by the PIs of this proposal, to drive carcinogenesis in NSCLC and malignant astrocytoma through regulation of several cancer-promoting pathways. The overall goal of the proposed study is to evaluate plasma for the presence of the SULFs and consequences of SULF-bioactivity in order to develop novel biomarkers for the early detection of NSCLC and malignant astrocytoma. The SULFs are unique as they modulate the binding of a multiplicity of signaling molecules, including Wnts, VEGF, and FGF-1, by acting on the 6O-sulfation of glucosamine (6OS) on heparan sulfate proteoglycans (HSPGs). As extracellular enzymes that are both tethered to the cell membrane and secreted, the SULFs and their HSPG substrates are present in the extracellular environment and have great potential as novel biomarkers for early detection of cancer in body fluids. This innovative project assembles a diverse team of investigators to integrate mechanistic studies of SULF function in cancer with practical applications of this knowledge to validate a novel biomarker for the early detection of cancer. Our Aims are: Aim 1: Characterize the expression levels of SULFs and the expression and sulfation status of their HSPG substrates in tumor samples from NSCLC and astrocytoma patients. Aim 2: Determine SULF levels in plasma and correlate these with tumor presence and progression Aim 3: Determine the 6OS sulfation status of HSPGs in plasma and correlate these with tumor presence and progression. Aim 4: Characterize the plasma levels of heparin-binding factors (growth factors, morphogens, cytokines, chemokines) that are potentially mobilized by SULF action in the tumor and correlate with tumor SULF levels. Our investigation of novel SULF-based biomarkers could lead to ELISAs for the early diagnosis of NSCLC and malignant astrocytoma and could become a new basis for patient management. In addition, these studies will promote collaborations and stimulate Trans-Alliance projects aimed at identifying how changes in cellular carbohydrates promote cancer progression and how to use this information to identify biomarkers for the early cancer detection.