Risk factor structure of heart failure in patients with cancer after treatment with anticancer agents' assessment by big data from a Japanese electronic health record.

As the prognosis of cancer patients has been improved, comorbidity of heart failure (HF) in cancer survivors is a serious concern, especially in the aged population. This study aimed to examine the risk factors of HF development after treatment by anticancer agents, using a machine learning-based analysis of a massive dataset obtained from the electronic health record (EHR) in Japan. This retrospective, cohort study, using a dataset from 2008 to 2017 in the Diagnosis Procedure Combination (DPC) database in Japan, enrolled 140,327 patients. The structure of risk factors was determined using multivariable analysis and classification and regression tree (CART) algorithm for time-to-event data. The mean follow-up period was 1.55 years. The prevalence of HF after anticancer agent administration were 4.0%. HF was more prevalent in the older than the younger. As the presence of cardiovascular diseases and various risk factors predicted HF, CART analysis of the risk factors revealed that the risk factor structures complicatedly differed among different age groups. The highest risk combination was hypertension, diabetes mellitus, and atrial fibrillation in the group aged ≤ 64 years, and the presence of ischemic heart disease was a key in both groups aged 65-74 years and 75 ≤ years. The machine learning-based approach was able to develop complicated HF risk structures in cancer patients after anticancer agents in different age population, of which knowledge would be essential for realizing precision medicine to improve the prognosis of cancer patients.

Tenascin C protects aorta from acute dissection in mice.

Acute aortic dissection (AAD) is caused by the disruption of intimomedial layer of the aortic walls, which is immediately life-threatening. Although recent studies indicate the importance of proinflammatory response in pathogenesis of AAD, the mechanism to keep the destructive inflammatory response in check is unknown. Here, we report that induction of tenascin-C (TNC) is a stress-evoked protective mechanism against the acute hemodynamic and humoral stress in aorta. Periaortic application of CaCl2 caused stiffening of abdominal aorta, which augmented the hemodynamic stress and TNC induction in suprarenal aorta by angiotensin II infusion. Deletion of Tnc gene rendered mice susceptible to AAD development upon the aortic stress, which was accompanied by impaired TGFß signaling, insufficient induction of extracellular matrix proteins and exaggerated proinflammatory response. Thus, TNC works as a stress-evoked molecular damper to maintain the aortic integrity under the acute stress.

Blood pressure variability activates cardiac mineralocorticoid receptor and induces cardiac remodeling in hypertensive rats.

BACKGROUND: Hypertensive patients with large blood pressure variability (BPV) have aggravated target organ damage. Because the aldosterone/mineralocorticoid receptor (MR) system is a possible mechanism of hypertensive organ damage, we investigated in spontaneously hypertensive rats (SHRs) whether a specific MR blocker, eplerenone, would prevent BPV-induced aggravation of hypertensive cardiac remodeling. METHODS AND RESULTS: A rat model of a combination of hypertension and large BPV was created by performing bilateral sinoaortic denervation (SAD) in SHRs. SAD increased BPV without changing mean BP. SAD induced perivascular macrophage infiltration and aggravated myocardial fibrosis and cardiac hypertrophy, resulting in LV systolic dysfunction. Immunohistostaining revealed SAD-induced translocation of MRs into the nuclei (ie, MR activation) of the intramyocardial arterial medial cells and cardiac myocytes. SAD increased phosphorylation of p21-activated kinase1 (PAK1), a regulator of MR nuclear translocation. Chronic administration of a subdepressor dose of eplerenone prevented MR translocation, macrophage infiltration, myocardial fibrosis, cardiac hypertrophy, and LV dysfunction, while not affecting BPV. Circulating levels of aldosterone and cortisol were not changed by SAD. CONCLUSIONS: Eplerenone inhibited the aggravation of cardiac inflammation and hypertensive cardiac remodeling, and thereby prevented progression of LV dysfunction in SHRs with large BPV. This suggests that the PAK1-MR pathway plays a role in cardiac inflammation and remodeling induced by large BPV superimposed on hypertension, independent of circulating aldosterone.

New computer model for prediction of individual 10-year mortality on the basis of conventional atherosclerotic risk factors.

BACKGROUND: Large cohort studies have revealed that subjects with atherosclerotic risk factors have high mortality. However, there has been no method to predict individual mortality based on these risk factors. Accordingly, we developed a computer model predicting the 10-year mortality of an individual with atherosclerotic risk factors. METHODS: We enrolled two different cohorts in Japan. One was from Tanushimaru-town and the other was from Uku-town. Residents over the age of 40 underwent baseline examinations and were followed-up for ten years. 1851 Subjects in Tanushimaru-town were randomly divided into 1486 training samples and 365 test samples. We applied supervised statistical pattern recognition (SSPR) techniques to develop, using the training samples, a computer model to predict the 10-year mortality of an individual based on 6 conventional risk factors. The test samples were then used to evaluate the predictive accuracy. RESULTS: There were 49 deaths and 316 survivors in the test samples in Tanushimaru-town. The correctly simulated number of deaths and survival was 36 and 250, respectively. The predictive accuracy of death was 73.5% (36/49) and that of survival was 79.1% (250/316) with c-statistics of 0.827. In order to verify our model, we predicted death and survival for the other test samples (Uku-town, n = 170). The predictive accuracy of death was 72.9% (35/48) and that of survival was 76.2% (93/122) with c-statistics of 0.848. CONCLUSIONS: This is the first computer model to use SSPR methods to estimate individual 10-year mortality based on conventional risk factors with high accuracy.

Glycolysis module activated by hypoxia-inducible factor 1alpha is related to the aggressive phenotype of hepatocellular carcinoma.

An increased level of glycolysis, an intracellular hallmark of neoplasms, enables cancer cells to survive under various conditions. To elucidate the role of increased glycolysis in the progression of hepatocellular carcinoma (HCC), we investigated the associations between the expression patterns of 14 glycolysis-related genes and clinicopathologic factors in 60 HCCs by using pooled transcriptome data. We then evaluated the therapeutic efficacy of the knockdown of ENO1, which is encoded by a glycolysis-related gene, in HCC cells. Among the 14 genes, levels of 8 genes (GPI, ALDOA, TPI1, GAPD, PGK, PGAM, ENO1 and PKM), all of which can be transcriptionally activated by hypoxia-inducible factor 1alpha (HIF-1alpha), were significantly higher in HCC with venous invasion (VI) than in HCC without VI. Our cluster analysis showed that HCC patients with activation of the 8 HIF-1alpha-regulated genes had significantly shorter overall survival (P=0.023) than did HCC patients without increased expression levels of these genes. The association between the levels of ENO1 and VI was confirmed in an independent sample set of 49 HCCs by real-time reverse-transcription PCR. The knockdown of ENO1 by small-interfering RNA significantly inhibited the proliferation of an HCC cell line (HLE cells) in both the glucose-rich and glucose-free conditions, accompanied by a decreased S phase and increased G2/M phase of the cell cycle. Collectively, these data suggest that activation of an HIF-1alpha-regulated glycolysis module is closely related to the aggressive phenotype of HCC, and that ENO1, a glycolysis module gene, might serve as a new target to circumvent HCC metastasis.

Relation between serum levels of cell-free DNA and inflammation status in hepatitis C virus-related hepatocellular carcinoma.

Our study revealed that the level of circulating cell-free DNA (cfDNA) is increased in the serum of patients with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). To gain insight into the mechanism underlying this phenomenon, we examined the association between cfDNA levels and various clinicopathological factors in 96 patients with HCV-related HCC and 99 non-HCC patients with HCV. Using pooled DNA microarray data, we profiled the expression patterns of inflammatory cytokine genes in 14 primary tumors from the group of HCC patients. We found that there were positive associations between the cfDNA level, aspartate aminotransferase levels and the number of leukocytes and neutrophils in patients with HCV-related HCC but not in non-HCC patients with HCV. The serum cfDNA level was not associated with other clinicopathological factors in HCC or non-HCC patients. A cluster analysis based on the inflammatory cytokine gene data revealed that HCCs with a high serum cfDNA level had increased levels of several inflammatory cytokine genes, suggesting that the serum cfDNA level is associated with the inflammatory status in primary tumors in HCV-related HCC.

A three-gene predictor for early intrahepatic recurrence of hepatocellular carcinoma after curative hepatectomy.

We previously developed a DNA microarray-based system that out-performs traditionally used clinical parameters for prediction of early intrahepatic recurrence (IHR) of hepatocellular carcinoma (HCC). Because DNA microarray is too expensive for daily clinical use, we used a quantitative real-time reverse transcription-polymerase chain reaction (QRT-PCR) to develop a lower-cost predictor for early IHR. From the 12 early IHR-related genes integrated in the previous predictor, we selected 6 genes whose levels showed the strongest association between data from the 2 distinct DNA microarray platforms with the same sample set. Expression of these 6 genes relative to that of GAPDH was measured by QRT-PCR in 82 HCCs. Of the 82 HCCs, 39 and 43 were assigned to training and independent test sets, respectively. By searching all combinations (n=2-6) of the 6 genes, we found an optimal combination of 3 genes (HLADRA, DDX17 and LAPTM5) that minimized the leave-one-out error for prediction of early IHR in the training set. The 3-gene predictor constructed with the Fisher linear classifier correctly predicted early IHR or non-recurrence in 35 (81.4%) of 43 HCCs in the independent test set and had a high positive predictive value of 72.7% and a high negative predictive value of 84.4%. Multivariate analysis with the stepwise logistic regression showed that the 3-gene predictor [F(x)<0] was an independent risk factor for early IHR (risk ratio, 13.6; p=0.006), indicating its potential as an easy-to-use predictor for accurate prediction of early IHR of HCC.

Resampling based on geographic patterns of hepatitis virus infection reveals a common gene signature for early intrahepatic recurrence of hepatocellular carcinoma.

The majority of hepatocellular carcinomas (HCCs) correlated with infection by either hepatitis B or C virus (HBV or HCV) showing various geographic distributions, making it impossible to identify common gene signatures responsible for HCC recurrence. In this study we performed in silico resampling analysis of DNA microarray data that can reproduce virtually the geographic distribution pattern of HBV and HCV in 6 representative geographic regions. With the use of the Fisher ratio, genes associated with early intrahepatic recurrence of HCC within 1 year of surgery were identified in the 6 geographic virtual cohorts, each consisting of 1,000 virtual samples. The top 100 genes among each virtual cohort were compared. Many human leukocyte antigen (HLA) family genes were common among the 6 geographic virtual cohorts, suggesting that this gene family represents the pathway most responsible for early intrahepatic recurrence of HCC worldwide. This resampling approach is useful for identifying common pathways involved in various aspects of HCC.

Identification of ID2 associated with invasion of hepatitis C virus-related hepatocellular carcinoma by gene expression profile.

Portal vein invasion (PVI) is a hallmark of metastatic potential of hepatocellular carcinoma (HCC) and is frequently found at a stage of moderately differentiated HCC. To identify genes involved in PVI of HCC associated with hepatitis C virus (HCV), we performed a comprehensive analysis of 12,600 genes in 35 moderately differentiated HCV-related HCCs by DNA microarray. Our supervised learning method identified 35 genes involved in PVI. Among the 35 identified genes, we focused on the inhibitor of DNA binding 2 (ID2), because it encodes a liver-rich dominant-negative helix-loop-helix protein. The microarray results for ID2 were reproduced by quantitative real-time reverse transcription (QRT)-PCR and Western blot analyses. In an independent set of HCV-related HCCs (n=28) and HCV-unrelated HCCs (n=14), our QRT-PCR showed that decrease in ID2 mRNA levels were associated with PVI in HCV-related HCC but not HCV-unrelated HCC. In conclusion, our results strongly suggest that ID2 plays an important role in PVI process of HCV-related HCC.

Different molecular pathways determining extrahepatic and intrahepatic recurrences of hepatocellular carcinoma.

Recent genome-wide screens have identified genes associated with the metastatic potential of hepatocellular carcinoma (HCC); however, there is little overlap between the identified genes, and interpretations of the results remain controversial. These inconsistencies may be related to differences in the sample populations, use of distinct microarray platforms and algorithms, and the complicated modes of HCC recurrence. We investigated the gene expression profiles of extrahepatic recurrence (EHR) and early intrahepatic recurrence (IHR), which are two representative modes of recurrence of HCC attributable to metastasis. We used DNA microarray analysis and identified 46 signature genes for EHR in 35 HCCs in a supervised learning manner. The obtained gene expression profile was compared with that for early IHR that was determined previously in the same manner. The 46 signature genes for EHR included many cell adhesion-related genes (ITGA6, SPP1, DNMBP, CD44 and POSTN), which all showed higher expression in HCC with EHR than in HCC without EHR. The 46 signature genes for early IHR included 10 immune response-related genes, which all showed lower expression in HCC with early IHR than in HCC without early IHR. The signature genes for EHR included only two immune response-related genes (P=0.013). These results suggest that alteration of the cell adhesion system plays a central role in EHR and that reduction of the immune response is a specific step in early IHR. These results indicate that the metastatic processes in EHR and early IHR involve different molecular pathways.

Involvement of c-myc-regulated genes in hepatocellular carcinoma related to genotype-C hepatitis B virus.

PURPOSE: The purpose of this study was to elucidate the molecular basis of hepatocellular carcinoma (HCC) caused by genotype-C hepatitis B virus (HBV). METHODS: We compared molecular profiles of 15 HCCs and five non-tumorous livers, all of which were associated with genotype-C HBV infection, using DNA microarray technology. RESULTS: Our supervised learning identified 237 genes whose expression differed between HCCs and non-tumorous livers. This result was validated by a false discovery rate of 0%. Levels of expression of 35 and 202 genes were higher and lower, respectively, in HCCs than in non-tumorous livers. Among the 237 genes, we highlighted the top 35 upregulated and top 35 down regulated genes in tumor. Interestingly, when overlapping genes were excluded, 12 (e.g., NM23-H2, MCM7, PARP1, YWHAH, HSPB1, and MSH2) of the top 34 upregulated genes and five (e.g., MT1A and MT3) of the top 33 downregulated genes were c-myc-regulated genes. The microarray data for five randomly selected genes (MCM7, UBE2L3, PPIA, CXCL12, and ASS) were confirmed by quantitative real-time reverse transcription-polymerase chain reaction. CONCLUSIONS: Our results indicate that many c-myc-regulated genes are involved in genotype-C-HBV-related HCC, suggesting that c-myc is related to the hepatocarcinogenic activity of genotype-C HBV.

Esophageal squamous cell carcinomas with distinct invasive depth show different gene expression profiles associated with lymph node metastasis.

We examined the gene expression profiles of esophageal squamous cell carcinomas (ESCCs) with respect to degree of invasive depth and lymph node (LN) involvement in a large cohort. We used high-density oligonucleotide microarrays to examine the expression of 22,115 genes in 54 ESCCs and 11 non-cancerous esophageal tissues. We found that 4,155 genes were biologically significant in both ESCC and non-cancerous esophageal tissue by analysis of Present Call (hybridization quality by Affymetrix) throughout all samples. From these genes, we used a supervised learning method to select genes responsible for the development of ESCC. We found that 999 genes were expressed differentially in pT1/pN0 tumors vs. non-cancerous esophageal tissue. In the same manner, 48, 66 and 30 genes were expressed differentially in pT1/pN0 tumors vs. pT1/pN1 tumors, pT1/pN0 tumors vs. pT2-4/pN0 tumors and pT2-4/pN0 tumors vs. pT2-4/pN1 tumors, respectively. Intriguingly, there were no overlaps between the 48 LN metastasis-related genes of pT1 tumors and the 30 LN metastasis-related genes of pT2-4 tumors, suggesting that ESCCs with distinct invasive depths express different genes linked to LN metastasis. Our present results suggest that the degree of invasive depth must be considered when predicting LN metastasis of ESCC from gene expression profiles.

Patterns of expression of cytochrome P450 genes in progression of hepatitis C virus-associated hepatocellular carcinoma.

Cytochrome P450 (CYP) genes are involved in the pathogenesis of hepatocellular carcinoma (HCC). To examine changes in expression of CYPs in HCC arising from hepatitis C virus (HCV)-infected liver, we used oligonucleotide array data of 27 CYPs from samples of 50 HCV-associated HCCs, five HCV-infected non-tumorous livers, and six HCV-negative normal livers. Progression of primary HCC can be characterized by decrease in the grade of tumor differentiation, increased frequency of venous invasion and increased tumor size. On the basis of tumor differentiation, the self-organizing map (SOM) classified the 27 CYPs into four groups. The first group contained 11 CYPs, including the CYP2C and CYP4F families, that showed decreased expression in parallel with progression of HCV-infected liver to HCC with less differentiation. The second group contained CYP-IID, CYP3A7 and CYP27A1, genes that showed high levels of expression specific to well differentiated HCC. The third group contained 5 sterol-metabolizing CYPs with levels lower in HCV-infected livers than in HCV-uninfected livers. The last group included the CYP2E1 and CYP3A families. Among the 27 CYPs, levels of 7 (CYP2B6, CYP-IIC, CYP2C9, CYP2C19, CYP3A5, CYP4F3 and CYP27A1) were significantly lower and levels of 2 (CYP2E1 and CYP4F2) were slightly lower in HCC with venous invasion than in HCC without venous invasion. Levels of CYP-IIC and CYP2C9 were inversely associated with tumor size. In contrast, levels of CYP51A1 were positively associated with tumor size. Our present study revealed that expression of specific CYPs was altered in conjunction with progression of HCV-associated HCC. These CYPs may serve as markers of progression and molecular targets for treatment of HCV-associated HCC.

Molecular dissection of a medicinal herb with anti-tumor activity by oligonucleotide microarray.

It is difficult to understand precisely the physiological actions of herbs because they contain a complex array of constituent molecules. In the present study we used DNA microarray data for 12600 genes to examine the anti-proliferative activity of the herb Coptidis rhizoma and eight constituent molecules against eight human pancreatic cancer cell lines. We identified 27 genes showing strong correlation with the 50% inhibitory dose (ID50) of C. rhizoma after 72-h exposure. Hierarchical cluster analysis with correlation coefficients between expression levels of these 27 C. rhizoma-related genes and the ID50 of each constituent molecule classified these test molecules into two clusters, one consisting of C. rhizoma and berberine and the other consisting of the remaining seven molecules. Our results suggest that one molecule, berberine, can account for the majority of the anti-proliferative activity of C. rhizoma and that DNA microarray analyses can be used to improve our understanding of the actions of an intact herb.

Self-organizing-map-based molecular signature representing the development of hepatocellular carcinoma.

Using high-density oligonucleotide array, we comprehensively analyzed expression levels of 12600 genes in 50 hepatocellular carcinoma (HCC) samples with positive hepatitis C virus (HCV) serology (well (G1), moderately (G2), and poorly (G3) differentiated tumors) and 11 non-tumorous livers (L1 and L0) with and without HCV infection. We searched for discriminatory genes of transition (L0 vs. L1, L1 vs. G1, G1 vs. G2, G2 vs. G3) with a supervised learning method, and then arranged the samples by self-organizing map (SOM) with the discriminatory gene sets. The SOM arranged the five clusters on a unique sigmoidal curve in the order L0, L1, G1, G2, and G3. The sample arrangement reproduced development-related features of HCC such as p53 abnormality. Strikingly, G2 tumors without venous invasion were located closer to the G1 cluster, and most G2 tumors with venous invasion were located closer to the G3 cluster (P=0.001 by Fisher's exact test). Our present profiling data will serve as a framework to understand the relation between the development and dedifferentiation of HCC.

Tumor HLA-DR expression linked to early intrahepatic recurrence of hepatocellular carcinoma.

The outcome of patients with hepatocellular carcinoma (HCC) remains poor because of the high frequency of intrahepatic recurrence (IHR), particularly early IHR within 1 year of hepatectomy. To search for genes involved in early IHR, we performed DNA microarray analysis in a training set of 33 HCCs and selected 46 genes linked to early IHR from approximately 6,000 genes by means of a supervised learning method. Gene selection was validated by a false discovery rate of 0.37%. The 46 genes included many immune response-related genes, which were all downregulated in HCCs with early IHR. Four of these genes (HLA-DRA, HLA-DRB1, HLA-DG and HLA-DQA), encoding MHC class II antigens, were coordinately downregulated in HCCs with early IHR compared to levels in HCCs with nonrecurrence. A cluster analysis reproduced expression patterns of the 4 MHC class II genes in 27 blinded HCC samples. To localize the major site of production of HLA-DR protein in the tumor, we used 50 frozen specimens from 50 HCCs. Immunofluorescence staining showed that HLA-DR protein levels in tumor cells, but not in stromal cells, were associated with the transcription levels of HLA-DRA determined by both DNA microarray analysis and real-time quantitative reverse transcription-PCR. Univariate analysis showed that tumor HLA-DR protein expression, pTNM stage and venous invasion were associated with early IHR. Multivariate analysis showed that tumor HLA-DR protein expression was one of the independent risk factors for early IHR, suggesting HLA-DR protein potential as a biomarker and a molecular target for therapeutic intervention.

Sex-based molecular profiling of hepatitis C virus-related hepatocellular carcinoma.

It has been suggested that sex affects not only the incidence of hepatocellular carcinoma (HCC) but also the outcome after treatment. However, no sex-specific therapeutic targets for HCC have been identified. Identification of sex-specific genes will allow for the development of more personalized therapies. To this end, we investigated the expression of approximately 6000 genes in 50 samples of hepatitis C virus (HCV)-related HCC by oligonucleotide microarray. Our supervised learning method and subsequent random permutation test identified 27 genes that were differentially expressed in samples from male (n=34) and female (n=16) patients. Our gene selection was validated by a false discovery rate of only 0.5%. For the 27 genes, expression levels of 12 were higher and expression levels of 15 were lower in HCC samples from men than in HCC samples from women. For the cell proliferation-related genes identified, expression levels of PRDX1 were relatively high in HCC samples from men, and expression levels of PRDX3 were relatively high in HCC samples from women. The DNA microarray data for PRDX1 and PRDX3 were reproduced by reverse transcription-PCR analysis. Our results suggest that these 27 genes may serve as molecular targets or markers for sex-specific treatment of HCV-related HCC. Further studies are needed to elucidate their possible roles in male and female patients with HCV-related HCC.

Molecular signature in three types of hepatocellular carcinoma with different viral origin by oligonucleotide microarray.

Chronic infection with hepatitis B or C virus (HBV or HCV) is the most clearly established risk factor for hepato-cellular carcinoma (HCC). One type of HCC (non-B, non-C HCC) also appears to develop in patients negative for both HBV and HCV. Using a supervised learning method, we investigated gene expression in 11 non-B, non-C HCCs with high-density oligonucleotide microarrays, and compared the patterns of gene expression with those of HBV-infected HCCs (B-type HCCs) and HCV-infected HCCs (C-type HCCs) in the previous dataset. Our gene selection identified 112 and 64 genes that were differentially expressed in non-B, non-C HCC in comparison with B- and C-type HCCs, respectively. In both gene selections, we found that the false discovery rate, the percentage of genes identified by chance, was less than 5%. Additionally, in combination with the previous data, our present data revealed a set of genes specific to each type of B- and C-type HCCs and non-B, non-C HCC. Among these, an interferon-induced gene, IFI27, was differentially expressed among all three types of HCCs, and this result was confirmed by RT-PCR. Thus, our present study provides a framework to characterize the molecular features in the three subtypes of HCC with different viral origin.

Altered Levels of Cytochrome P450 Genes in Hepatitis B or C Virus-infected Liver Identified by Oligonucleotide Microarray.

BACKGROUND: Molecular pathogenesis of hepatocellular carcinoma (HCC) remains to be clarified. Many studies with DNA chip technology have revealed altered levels of several cytochrome P450 (CYP) family genes in human HCC. However, little is known about their alterations in hepatitis B virus (HBV)- and hepatitis C virus (HCV)-infected livers. MATERIALS AND METHODS: We here used high-density oligonucleotide arrays to evaluate alterations of CYP genes in five of each HBV- or HCV-infected livers in comparison with six normal livers. We extracted the data of 32 CYP genes from those of 12600 genes. RESULTS: Among these 32 CYPs, expression levels of four genes were insignificant. The expressions of CYP1B1 and CYP3A7 were up-regulated, whereas the expressions of 12 other CYPs, including CYP2A6, CYP2A7 and CYP2C19, were down-regulated in HBV- and/or HCV-infected livers compared with normal livers. CONCLUSION: These data will allow us to better understand the roles of CYPs in the pathogenesis of HBV- and HCV-related HCCs.

Gene expression profile linked to p53 status in hepatitis C virus-related hepatocellular carcinoma.

To clarify the role of p53 in 22 hepatitis C virus (HCV)-infected hepatocellular carcinomas (HCCs), we compared the gene expression profiles of HCCs with wild-type p53 (wt-p53) (n=17) and those with mutant-type p53 (mt-p53) (n=5) by oligonucleotide microarray analysis. Among 83 p53-related genes identified by a supervised learning method, 25 were underexpressed, and 58 were overexpressed in mt-p53 HCCs compared with wt-p53 HCCs. With a computer search, we identified consensus p53-binding sequences in the 3-kb region upstream of the translation initiation site in 59 of the 83 genes, suggesting that the in vivo p53-associated transcription system is very complicated. These data will provide additional insights into p53-related pathogenesis in HCV-infected HCC.