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Pancreatic cancer (PC) is characterized by rapid tumor spread, and very few patients with PC survive for more than 5 years. It is imperative to discover additional diagnostic biomarkers or specific therapeutic targets in order to improve the treatment of patients with PC. In search for useful biomarkers, we analyzed ten pairs of non-cancerous and cancer tissues from patients with PC by two-dimensional gel electrophoresis (2-DE). Nineteen protein spots showed differential expression on 2-DE gels between the cancer and non-cancerous tissues. Six upregulated protein spots were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) as calreticulin, glutathione synthetase, stathmin, vinculin, α-enolase and glyceraldehyde-3-phosphate dehydrogenase. Western blotting demonstrated that vinculin was predominantly expressed in the pancreatic cancer tissues compared with to non-cancerous tissues. Our findings indicate that vinculin may be a clinically useful biomarker of PC.

Hepatocellular carcinoma (HCC) often exhibits a poor prognosis due to metastatic spread caused by portal vein invasion (PVI). In the present study, we attempted to identify a novel therapeutic target related to PVI of HCC. Based on pooled genomic data, we identified RD RNA binding protein (RDBP), a member of the negative elongation factor (NELF) transcription elongation regulatory complex, to be preferentially overexpressed in HCC with PVI. We used quantitative reverse transcription polymerase chain reaction (RT-PCR) and immuno-histochemical analyses to investigate the relationship between RDBP mRNA and protein with metastatic potential in sample sets of hepatitis C virus (HCV)-related HCC and corresponding non-HCC liver tissues. We also used the small interfering RNA technique to examine the role of RDBP in invasion and proliferation of HCC cells in vitro. Our data showed that both mRNA and protein levels of RDBP were significantly higher in HCC compared to non-HCC liver tissue, and that these levels were also significantly higher in HCC with PVI compared to HCC without PVI. Multivariate analysis revealed that RDBP protein levels were an independent risk factor for early intrahepatic recurrence of HCC within 2 years of surgery. Knockdown of RDBP protein significantly inhibited the proliferation and invasion of cells in vitro. These data demonstrate that RDBP is related to the metastatic potential of HCC, suggesting a possible candidate for prevention of HCC cell metastasis.

Pancreatic cancer (PC) is one of the most deadly malignant tumors. The aim of this study was to identify potential biomarkers for PC. Using two-dimensional gel electrophoresis and liquid chromatography-tandem mass spectrometry, the proteomic profiles of pancreatic cancerous and non-cancerous tissues from ten patients with PC were compared. One of the numerous spots that showed stronger intensity in cancerous compared to non-cancerous tissues was identified as non-muscle cofilin (cofilin-1). This up-regulation was validated by Western blot analysis. It is noteworthy that Western blot analysis showed significantly lower expression of muscle cofilin (cofilin-2) in pancreatic cancerous tissues compared to non-cancerous tissues. This is the first time that cofilin isoforms (cofilin-1/2) have been identified to be differentially expressed in pancreatic cancerous tissues. Therefore, cofilin isoforms may serve as candidates for clinically useful biomarkers or therapeutic targets for PC.

Pancreatic cancer (PC) is one of the most lethal malignant tumors because of late diagnosis and the lack of response to various therapies. To identify potential biomarkers in cancerous serum from early stage PC patients, we carried out two-dimensional gel electrophoresis (2-DE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) to compare the serum proteomic profiles from 45 patients with PC and 20 healthy volunteers. Seven spots showed differential expression on 2-DE gels and two up-regulated protein spots were identified by LC-MS/MS as α-1-antitrypsin (AAT). These protein spots were also confirmed by Western blotting. This is the first time that AAT isoforms have been identified as potential serum biomarkers for PC. The serum isoforms of AAT may be clinically useful for PC diagnosis and monitoring.

Biological characteristics of a tumor are primarily affected by its genomic alterations. It is thus important to ascertain whether there are genomic changes linked with DNA ploidy and/or chromosomal instability (CIN). In the present study, using fresh-frozen samples of 46 invasive breast cancers, laser scanning cytometry, array-based comparative genomic hybridization, and chromosome fluorescence in situ hybridization were performed to assess DNA ploidy, DNA copy number aberrations (DCNAs), and CIN status. Both ploidy and CIN status were examined in 36 tumors, resulting in 23 aneuploid/CIN+ tumors, 1 aneuploid/CIN-, 2 diploid/CIN+, and 10 diploid/CIN- tumors. Comparison of the aCGH data with the DNA ploidy and CIN status identified cytogenetically 11 characteristic breast cancers with distinctive DCNAs. The 11 tumors were classified into two types; one type is diploid/CIN- phenotype containing 4 DCNAs, and the other aneuploid/CIN+ phenotype containing 7 DCNAs. In 30 (65.2%) of the 36 breast cancers, the status of DNA ploidy and CIN depended on the type of DCNAs. Furthermore, the DNA ploidy phenotype depended on the dominant type of DCNAs even in tumors with a mixture of multiple DCNAs of one type and a single DCNA of the other type. Tumors with multiple DCNAs of both types represented aneuploidy and over three quarters of breast cancers carry at least one type of the DCNAs. These results suggested that, in breast cancers, the status of DNA ploidy and CIN was likely to determine at the beginning of carcinogenesis.

MUC1 is a tumor-associated antigen that is overexpressed in invasive ductal carcinomas of the pancreas (PC). MUC1-specific cytotoxic T lymphocytes (CTLs) recognize MUC1 molecules in a HLA-unrestricted manner. In this study, we performed adoptive immunotherapy (AIT) in patients with PC with CTLs stimulated by the MUC1-expressing human PC cell line YPK-1. To induce CTLs, peripheral blood mononuclear cells (PBMCs) were cultured for 3 days with inactivated YPK-1 cells and then stimulated with interleukin (IL)-2 for 7 days. The cytotoxicity of these cells against human cancer cell lines was analyzed, and a variety of antibodies were evaluated for their ability to inhibit cytotoxicity. We treated 8 patients with unresectable PC and 20 patients with resectable PC postsurgically. CTLs were induced as described above, suspended in 100 ml saline and injected intravenously. Induced CTLs were cytotoxic against 5 MUC1-expressing PC cell lines and a breast cancer cell line, regardless of the HLA phenotype. Low cytotoxicity was observed in 7 MUC1-negative cancer cell lines. Anti-CD3 monoclonal antibody (mAb) or anti-CD8 mAb strongly inhibited cytotoxicity against YPK-1, whereas anti-class I mAb showed no inhibition. YPK-1 cells incubated with anti-MUC1 mAb also showed low cytotoxicity. Clinically, the median survival time was 5.0 months for patients with unresectable PC treated with AIT. None of the 5 patients without liver metastasis showed hepatic recurrence. The median survival time was 17.8 months for 18 out of 20 patients with resectable PC who underwent curative surgery, and the 1-, 2- and 3-year survival rates after surgery were 83.3, 32.4, and 19.4%, respectively. Liver metastasis was found in only one patient and no side effects of AIT were observed. CTLs stimulated by a MUC1-expressing human pancreatic cancer cell line showed a strong tumor cytotoxic activity in a MUC1-specific and MHC-unrestricted manner. AIT with stimulated CTLs significantly suppressed the postsurgical hepatic recurrence of PC. Adjuvant immunotherapy with CTLs may be useful in the postsurgical treatment of PC.

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)

Although gemcitabine (GEM) is widely used in the treatment of pancreatic cancers, the molecular mechanisms that underlie its anti-tumor effects are not fully understood. To clarify the anti-tumor mechanism(s) of GEM, we studied a human pancreatic cancer cell line, YPK-1, that showed a 50% inhibitory concentration (IC50) of GEM of 6.3 x 10(-3) microg/ml after 72 h of exposure. Cell proliferation was perturbed by 6 to 72 h of exposure to GEM concentrations equal to one-half or one-quarter of the IC50. We used cDNA microarrays containing 2976 genes to identify genes with expression affected by exposure to GEM. The self-organizing map identified nine clusters, including 85 and 87 genes, that showed differential expression in response to exposure to one half and one quarter IC50 GEM, respectively. Of these, 24 genes were common to cells exposed to the two different concentrations of GEM. Most are signal transduction or transcription-related genes. The microarray data for two of these genes, SPARC and RPS8, were validated by RT-PCR. Although further studies are needed to examine whether the changes in expression profiles of these genes are specific to cells exposed to GEM, the present data provide insights into the anti-tumor effects of GEM on pancreatic cancers.

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.

The prognosis of pancreatic cancer is extremely poor, and development of new treatment modalities is needed. One such treatment could be specific immunotherapy. To evaluate safety and immunological responses, we conducted a phase I study of personalized peptide vaccination for pancreatic cancer patients (n=11). Namely, pre-vaccination peripheral blood mononuclear cells were screened for their reactivity in vitro to each of 14 or 16 peptides in HLA-A24(+) or -A2(+) patients, and only the reactive peptides (maximum: 4) were vaccinated in vivo. This regimen was generally well tolerated, although inflammatory reactions at the injection site were observed in 7 patients. Delayed-type hypersensitivity to peptides used for vaccination was observed in 7 patients. Increased cellular and humoral immune responses to at least one of peptides used for vaccination were observed in the post-vaccination PBMCs and sera from 4 of 8 patients and 4 of 10 patients tested, respectively. The 6- and 12-month survival rates for patients who received >3 vaccinations (n=10) were 80% and 20%, respectively. Due to tolerability and capability of inducing specific immunity, further development of personalized peptide-based immunotherapy for pancreatic cancer patients is warranted.

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.