Research Project
8312069
DESCRIPTION (provided by applicant): Hepatocellular carcinoma (HCC) and intrahepatic cholagiocarcinoma (ICC) usually go undetected until its late stages, with a 5-year survival rate less than 10%. The survival rate can, however, be as high as 40% if cancer is detected early. Unfortunately, early detection of HCC/ICC is not possible by current available screening tests such as ultrasound and image technologies. AFP is used as a diagnostic marker for HCC, however, low specificity and sensitivity limit its use. Additionally, no biomarker currently exists to reliably detect ICC. Therefore, a method of detecting HCC/ICC more effectively than the current methods would bring forward the management. Background and Objective: Recent studies have suggested that levels of serine protease inhibitor Kazal (SPIK) is highly related to HCC/ICC progression and over- expression of SPIK is correlated to short survival and early recurrence of HCC/ICC. While all data suggests that SPIK may be used as a more effective biomarker for detecting HCC/ICC, this had been complicated by other disease such as pancreatitis also led to higher serum SPIK levels. However, we have been able to demonstrate that SPIK secreted by liver cancer (LC-SPIK) can be distinguished from that secreted by pancreas as: (1) the quantity of LC-SPIK is significantly greater than that secreted by pancreatic cells, and (2) a molecular structural difference in the form of an additional 9- amino-acid fragment in the N-terminus is present in the LC-SPIK. Based on this discovery, we would be able to develop a specific antibody and diagnostic ELISA test kit that could use LC-SPIK as a more effective and specific biomarker for screening HCC/ICC than available currently. Approach: In phase I, Aim1: We will develop a prototype test system for quantifying LC-SPIK by constructing a specific monoclonal antibody against the 9 amino-acid segment in LC-SPIK with high sensitivity (at nanogram level) and specificity. Aim2. We will assess the performance of LC-SPIK in 160 patients with HCC and 90 patients with ICC. 200 serum samples from normal people, patients with pancreatitis and other liver disease (hepatitis and cirrhosis) will be used as controls. After completion of these studies we would have proved our concept and obtain a test system with high sensitivity and specificity to distinguish HCC/ICC from the subjects with pancreatitis and other liver diseases or normal liver. In phase II studies, Am3: we will standardize our technology and develop a test kit (HepatoDetect(R)) for screening HCC/ICC. This ELISA kit would be reliable, easy to operate and inexpensive. In Aim4: Using our kit, we will systematically determine the performance of LC-SPIK in a blinded sample sets including 300 specimens in each clinical group from HCC, ICC, normal liver, pancreatitis and other liver diseases such as hepatitis and cirrhosis to determine the specificity for HCC/ICC. Finally we will commercialize this kit after approved by FDA. Market: Because nearly 15 million people in US and 2 billions people in worldwide are infected by HBV or HCV, 30-40% of them have a high risk to develop HCC. For these people, routine examination of cancer is necessary. In addition, ICC is the second most common primary liver cancer after HCC and currently no reliable biomarker exists for detecting it, therefore, the market of detection HCC/ICC is huge. Competition: Currently, only AFP is used as a diagnostic marker for HCC but is less effective, there is no similar product in the market. PUBLIC HEALTH RELEVANCE: Currently, there is no effective biomarker to detect early occurrence of liver cancer (HCC and ICC) and its recurrence after surgical resection. However, overexpression of serine protease inhibitor Kazal (SPIK) was found in HCC and ICC and the level of SPIK protein in the serum of patients has been demonstrated to correlate with the progress of the cancers. In this proposal, we will develop an easy and quick diagnostic kit to specifically quantify serum SPIK and examine its effectiveness using serum samples from mice implanted with HCC tumors and determine whether SPIK can be a biomarker for diagnosis of HCC/ICC.
