Expression profiling in multistage hepatocarcinogenesis: Identification of HSP70 as a molecular marker of early hepatocellular carcinoma

Abstract

Hepatocellular carcinoma (HCC) associated with chronic liver disease evolves from precancerous lesions and early HCC to a progressed form. Nodule-in-nodule-type HCC (progressed HCC within early HCC) represents the transition from early to progressed HCC and, therefore, is useful in molecular genetic analysis of HCC progression during multistage carcinogenesis. We compared expression profiles among 7 early components and 7 progressed components of nodule-in-nodule-type HCCs and their corresponding noncancerous liver tissues with oligonucleotide array. Of the approximately 12,600 genes that were analyzed, a set of 95 genes provided a molecular signature that distinguished between early HCC components and their noncancerous liver tissues, and a set of 92 genes distinguished between progressed and early HCC components. Of these genes, the most abundantly up-regulated gene in early HCC components (P < .001) was heat-shock protein 70 (HSP70). Real-time quantitative reverse transcription polymerase chain reaction (RT-PCR) confirmed this finding. Further immunohistochemical examination of HSP70 revealed its significant overexpression in early HCC compared with precancerous lesions (P < .001) and in progressed HCC compared with early HCC (P < .001). In conclusion, molecular signatures were clearly different in noncancerous liver tissue as compared with the early and progressed components of nodule-in-nodule-type HCC. Moreover, HSP70 could be a sensitive marker for the differential diagnosis of early HCC from precancerous lesion or noncancerous liver, a difficult distinction for pathologists due to very well differentiated histology with little atypia in early HCC. (HEPATOLOGY 2003;37:198-207.) H epatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide and one of the leading causes of cancer death in Japan. 1 Despite remarkable advances in diagnostic and therapeutic techniques, the incidence of HCC is still on the increase. HCC occurs mainly in livers that are chronically diseased as a result of hepatitis virus infection. 2 Progression often leads to vascular invasion and intrahepatic metastasis. As is known for other cancers, 3 HCC is also characterized by an obvious multistage process of tumor progression. Histopathologic and molecular biological studies have revealed the multistep development of human HCCs. [4][5][6][7] It has been shown that small nodular hypercellular lesions known as adenomatous hyperplasia (AH) or atypical AH (AAH: AH with focally increased atypia but too indefinite for a diagnosis of HCC) appear in damaged liver infected with hepatitis virus B or C. These lesions develop into early HCC, which corresponds to in situ or microinvasive carcinoma, in which the portal tracts within the nodule are preserved, and then into progressed HCC through the stage of nodule-in-nodule-type HCC (progressed HCC within early HCC), which indicates a transition from early to progressed HCC. These pathologic findings are also supported by radiologic findings. 8,9

Pathologic diagnosis of early hepatocellular carcinoma: A report of the international consensus group for hepatocellular neoplasia # †

“…HSP70 is, in particular, a potent antiapoptotic survival factor. Chuma et al 47 reported HSP70 as the most abundantly up-regulated gene among a set of 12,600 genes in early HCC. Furthermore, it was significantly overexpressed in progressed HCC as compared with early HCC, and in the latter as compared with precancerous lesions.…”

Histological features of early hepatocellular carcinomas and their developmental process: for daily practical clinical application

“…Because such thickened trabecular structure cannot mix with noncancerous tissue, advanced HCCs show distinct margin even in a liver with an early stage of chronic liver disease. Various tumor markers, that is, HSP70, GPC3, and GS, also show incrementally more intense expression from early to advanced HCCs [25][26][27][28][29][30][31]. Vascularities of the tumors also change according to tumor development.…”

“…In addition to the morphological criteria, some attempts have been made recently to utilize immunohistochemical markers for the diagnosis of well-differentiated HCCs [25][26][27][28][29][30][31]. Heat shock protein 70 (HSP70) [25,26], glypican 3 (GPC3) [25,[27][28][29], and glutamine synthetase (GS) [25,30,31] have been used independently or in combination.…”

“…Heat shock protein 70 (HSP70) [25,26], glypican 3 (GPC3) [25,[27][28][29], and glutamine synthetase (GS) [25,30,31] have been used independently or in combination. These markers can be useful for the diagnosis of difficult lesions.…”

Heat shock response: hsp70 in environmental monitoring

“…Owing to their responsiveness to diverse forms of stress, the stress proteins have undergone widespread application in biomonitoring and environmental toxicology [5,[34][35][36][37][38][39][40][41]. As members of the Hsp70 are often the prominent proteins to be expressed following environmental insults, these stress proteins are, therefore, very useful indicators of cellular aggression, and have been used to monitor the impact of environmental factors on various animal species [42][43][44][45] as well as in in vitro models [28,37,41,46,47]. Hsp70 is the target molecule or molecule under investigation because it simultaneously takes part in defense, repair, or detoxification machinery of the cell and becomes a direct and specific indicator of cellular stress [30,[48][49][50][51].…”