Identification of Cystatin B as a Potential Serum Marker in Hepatocellular Carcinoma

Abstract

Purpose: The poor survival rate of hepatocellular carcinoma (HCC) is in part due to the inability to diagnose patients at an early stage. Therefore, the aim of this study was to search for candidate serum marker for HCC and to test their ability to distinguish a HCC from benign liver disease. Experimental Design: Genome-wide analysis by a microarray in 40 HCC patients was done between HCC and paired nontumor liver tissues. Expression of cystatin B (CSTB) was examined by mRNA expression analysis and immunohistochemistry.The serum CSTB levels were measured using a sandwich ELISA method in four groups, including normal healthy subjects (group 1, n = 52) and patients with noncirrhotic chronic hepatitis (group 2, n = 53), cirrhosis (group 3, n = 43), and HCC (group 4, n = 62). Results: Microarray and statistical analyses identified 248 genes that were expressed differently between HCC and nontumor liver tissues. One of them, CSTB, was expressed preferentially in the HCCs compared with the nontumor tissues, 36 of 45 specimens (80%) by Northern blot and semiquantitative reverse transcription-PCR analyses. The serum CSTB level was much higher in HCC patients than in those with nonmalignant chronic liver disease (groups 2 and 3; P < 0.0001).The receiver operating characteristic curve indicated 5.34 ng/mL to be the optimal value for CSTB, and the sensitivity and specificity for this CSTB value were 85.5% (95% confidence interval, 74.2-93.1%) and 53.1% (95% confidence interval, 42.7-63.4%), respectively, in distinguishing between patients with HCC and those with nonmalignant chronic liver disease. Conclusion: CSTB is specifically overexpressed in most HCCs and is also elevated in the serum of a large proportion of HCC patients. CSTB or the combination of CSTB and a-fetoprotein may be a useful marker for diagnosing patients with HCC with a high sensitivity.

Peptides in Low Molecular Weight Fraction of Serum Associated with Hepatocellular Carcinoma

“…This is not sufficient for an efficient detection of HCC. New biomarkers for early detection and prevention of HCC are needed and a search is under way in several laboratories [10][11][12][13]. The management of the disease is predicted to benefit from identification of appropriate serologic markers that would assist with the optimization of therapeutic decisions.…”

Cystatin B inhibition of TRAIL-induced apoptosis is associated with the protection of FLIPL from degradation by the E3 ligase itch in human melanoma cells

“…Bioscience and Biotechnology, Daejeon, Republic of Korea) and described elsewhere. 16 FLIP L cDNA and FLIP S cDNA cloned into the pCR vector were kindly provided by Dr. H Nakano (Juntendo University School of Medicine, Tokyo, Japan). 39 Figure 6 For caption see next page…”

“…6,21,25 There is increasing evidence that cystatin B expression is elevated in cancer cells, which may serve as a biomarker for disease progression and prognosis of patients. 14,16,17 However, the current understanding of the mechanism(s) of cystatin B action under physiological and pathological conditions remains largely confined to its ability to inhibit cysteine cathepsins. 33 With regard to regulation of apoptosis, cystatin B-deficient mice are known to exhibit increased apoptosis of cerebella granule cells associated with increased expression of apoptosis genes, many of which are not the genes encoding cysteine cathepsins.…”

“…15 Intriguingly, cystatin B is frequently expressed at high levels in cancer cells. 14,16,17 Although the biological significance of the high levels of expression remains to be elucidated, increased cystatin B either on tumor tissues or in serum has been reported to be a biomarker for disease progression in a number of cancers. 16,17 In view of the potential involvement of cysteine cathepsins in TRAIL-induced apoptosis of melanoma cells, we have tested if cystatin B has a role in the protection of melanoma cells against TRAIL-induced apoptosis.…”

“…14,16,17 Although the biological significance of the high levels of expression remains to be elucidated, increased cystatin B either on tumor tissues or in serum has been reported to be a biomarker for disease progression in a number of cancers. 16,17 In view of the potential involvement of cysteine cathepsins in TRAIL-induced apoptosis of melanoma cells, we have tested if cystatin B has a role in the protection of melanoma cells against TRAIL-induced apoptosis. We show in this report that cystatin B contributes to the resistance of melanoma cells to apoptosis induced by TRAIL, but this is, unexpectedly, not due to the inhibition of cysteine proteases, cathepsin B and L, in the majority of melanoma cell lines.…”