Keiko Takagi

Inhibition of MMP-9 transcription and suppression of tumor metastasis by pyrrole-imidazole polyamide.

(Cancer Sci 2010; 101: 759–766)

Abnormal nucleotide repeat sequence in the TGF-βRII gene in hepatocellular carcinoma and in uninvolved liver tissue

Replication error (RER)‐related genetic alterations are associated with a subset of hepatocellular carcinomas (HCCs) with multiple primary cancers. This study investigated whether mutations in the nucleotide repeats of three putative target genes of RER are associated with hepatocarcinogenesis. The genes examined were those encoding transforming growth factor β type II receptor (TGF‐βRII), BCL‐2‐associated X protein (BAX), and insulin‐like growth factor II receptor (IGF‐IIR). Tumour and non‐tumour hepatic tissues were examined in 48 HCC patients, 34 with solitary HCC and 14 who had double cancer with gastric cancer. Four double‐cancer cases showed an abnormal signal in the single nucleotide repeat (A)10 of the TGF‐βRII gene. These four were among the six RER‐positive cases in this series. The genotypes of the poly A tract of the TGF‐βRII gene in the liver tumour tissue of the four cases with an abnormal signal were (A)9/10, (A)9/10, (A)9/10, and (A)9/9. Five uninvolved liver tissue specimens from these four patients showed (A)9/10 and (A)9/9, (A)9/10, (A)10/10 and (A)9/9, respectively. The genotype in the stomach cancer specimens of these four patients was (A)10/10, indicating no germline mutation of the TGF‐βRII gene. There were no mutations in the nucleotide repeats of the BAX and IGF‐IIR genes in any of the liver tissue specimens. Abnormality of the nucleotide repeat in the TGF‐βRII gene occurred in the uninvolved liver tissue as well as the HCC tissue in some HCC patients. Such genetic instability may be gene‐specific and tissue‐specific in carcinogenesis. Copyright

DNA hypermethylation of zygote arrest 1 (ZAR1) in hepatitis C virus positive related hepatocellular carcinoma

BackgroundHepatocellular carcinoma (HCC) is one of the most common human malignancies in the world, and its prognosis is generally poor. Epigenetic alteration such as DNA methylation has been shown to be important in the development of human cancers including HCC. Here, we analyzed the methylation status of ZAR1, which has been reported to be aberrantly methylated in a few human cancers.MethodsWe investigated the methylation status of ZAR1 in 88 HCV-positive HCC and matched nontumorous liver tissue samples and 4 normal liver tissue samples used as a control using MassARRAY EpiTYPER. Further statistical analysis was performed to determine the relationship between methylation level and patient clinicopathological features and prognosis.ResultsCpG islands in ZAR1 exon 1 showed a higher methylation level in all 88 HCC than in nontumorous tissues. The hypermethylation group, whose cancer tissues showed a twofold or higher methylation level compared with nontumorous tissues, showed a significantly higher serum AFP (p = 0.018) and lower serum albumin (p = 0.001) and single rather than multiple tumors (p = 0.031) compared with the hypomethylation group. Multivariate regression analyses were performed to identify which of the following factors were the predictors of the hypermethylation group: serum albumin, AFP, and tumor multiplicity. This study showed that patients who had Zar1 hypermethylation in the HCC tissues had a significantly lower serum albumin level than those in the hypomethylation group (p = 0.007).ConclusionAlthough it is still unknown how ZAR1 hypermethylation affects HCC development, it could be a potential marker to detect HCV-related HCC.

Cell division cycle 34 is highly expressed in hepatitis C virus-positive hepatocellular carcinoma with favorable phenotypes

Despite tremendous efforts to develop curative agents, there are few effective drugs for the treatment of hepatocellular carcinoma (HCC). This is predominantly due to the variations in individual HCC cases. As numerous HCC cases have no mutations in known tumor-associated genes, identification of novel genes involved in the development and progression of human cancers is considered to be an urgent issue. In the present study, surgical specimens of HCC were analyzed for the expression patterns of ubiquitin-conjugating enzyme, cell division cycle 34 (CDC34), which is hypomethylated in its promoter region and exhibits elevated expression levels in mouse skin tumors. The results of the current study clearly indicated that the elevated CDC34 expression level in cancerous regions was significantly associated with favorable clinicopathological features, such as reduced alanine aminotransferase (ALT) levels and histological grades. Similarly, a higher T/N ratio, which is the ratio of CDC34 expression in HCCs to that in non-tumorous tissues, was significantly associated with favorable features, such as a lower indocyanin green retention rate after 15 min (ICG15R), reduced α-fetoprotein and smaller tumor size. These results indicate that the CDC34 expression level in HCC is a marker for predicting the HCC prognosis and that CDC34 acts as a tumor suppressor.

Gastrointestinal: Case of accidentally discovered splenic epidermoid cyst with serum CA19‐9 elevation

A 36-year old woman underwent upper gastrointestinal examination during a routine medical examination, which revealed an abnormality (Fig. 1a). She was admitted for further examination. She had no symptoms and her abdomen showed no obvious abnormality with palpation. Computed tomographic scan revealed an abdominal low-density tumor, which measured 8 cm in diameter, with partial calcification close to the stomach and spleen (Fig. 1b). She had no history of significant abdominal trauma. Results of physical and laboratory examinations were normal except for elevation of serum CA19-9 (carbohydrate antigen 19-9) levels of 244.4 U/ml. Surgical exploration suggested that a huge tumor originated from the spleen. Because malignancy and risk of rupture could not be denied, she underwent splenectomy. The excised specimen was a cystic lesion measuring 8.5 × 7.5 × 5.5 cm with necrosis and bleeding (Fig. 1c). Histopathologically, the removed specimen showed a unicystic lesion surrounded by splenic tissue with marked fibrosis and calcification (Fig. 2a). This cyst had eosinophilic contents with cell debris, cholesterol crystals and a few inflammatory cells. Although lining epithelium had been partially effaced, the cyst wall was mostly covered with thin, two to three-layered non-keratinizing stratified squamous epithelium having an intercellular bridge. A few ciliated cells were observed in the surface (Fig. 2a, inset). Immunohistochemically, the lining epithelium showed a full thickness positive reaction to both CK14 (Fig. 2b) and CK19 (Fig. 2c), and the upper half of the epithelium was positive for CA19-9 (Fig. 2d). This case was diagnosed as epidermoid cyst of the spleen. After one month of follow-up, the patient was in good clinical condition. Splenic cysts are classified into true cysts and pseudocysts, based on the presence or absence of lining epithelium. Among true splenic cysts, epidermoid cysts account for 90%. Even if true splenic cysts are benign, there are cases that show elevation of serum CA19-9. This condition can be explained by the CA19-9 positive cells that seem to produce this glycoprotein. CA19-9 will flow into blood if internal pressure of the cyst rises. There are various opinions on the origin of the cyst. In general, CK14 is a marker of stratified squamous epithelium, while CK19 is a marker of simple epithelium. In this case, the epithelium has both characteristics of simple and stratified squamous epithelium. The presence of CK19 and CA19-9 positive cells give us the impression that squamous metaplasia occurred in simple epithelium aberrantly embedded in the developing stage.