Polyomaviruses of the skin: integrating molecular and clinical advances in an emerging class of viruses.

BACKGROUND: Human polyomaviruses (HPyVs) are small, nonenveloped, double-stranded DNA viruses that express tumour antigen proteins. Fourteen species of polyomaviruses have been discovered in humans, and since the 2008 discovery of the first cutaneous polyomavirus - Merkel cell polyomavirus (MCPyV) - six more species have been detected in the skin: trichodysplasia spinulosa-associated polyomavirus (TSPyV), HPyV6, HPyV7, HPyV9, HPyV10 and HPyV13. Of these cutaneous species, only MCPyV, TSPyV, HPyV6 and HPyV7 have been definitively associated with diseases of the skin, most commonly in immunocompromised individuals. MCPyV is a predominant aetiology in Merkel cell carcinomas. TSPyV is one of the aetiological factors of trichodysplasia spinulosa. HPyV6 and HPyV7 have been recently linked to pruritic skin eruptions. The roles of HPyV9, HPyV10 and HPyV13 in pathogenesis, if any, are still unknown, but their molecular features have provided some insight into their functional biology. RESULTS: In this review, we summarize the known molecular mechanisms, clinical presentation and targeted therapies of each of the eight cutaneous HPyVs. CONCLUSIONS: We hope that heightened awareness and clinical recognition of HPyVs will lead to increased reports of HPyV-associated diseases and, consequently, a more robust understanding of how to diagnose and treat these conditions.

Adenocarcinoma arising from tubulovillous adenoma in a native bladder following gastrocystoplasty.

Gastrocystoplasty is a surgical form of bladder augmentation which improves bladder capacity and compliance. Patients who undergo bladder augmentation with a gastric remnant are at increased risk for malignancy. The most common types of tumors in this situation were adenocarcinoma and urothelial carcinoma. Most of the adenocarcinomas arise in the gastric remnant or anastomotic site, and adenocarcinomas arising in the residual native bladder are extremely rare. We report on a patient who received gastrocystoplasty 16 years ago. She suffered from recurrent urinary tract infections for a year and cystoscopy showed a tumor in the bladder trigone. Pathologic examination showed tubulovillous adenoma with malignant transformation to adenocarcinoma. The tumor consisted of intact adenomatous architecture from low-grade dysplastic gland to adenocarcinoma, which suggested that the pathogenesis might be related to intestinal metaplasia and dysplasia. The unique location and immunohistologic findings of the tumor suggested that it originated in the bladder mucosa.

Crossed fused renal ectopia with segmental fusion of bilateral ureters and abdominal aortic anomalies in a patient with caudal regression syndrome.

Caudal regression syndrome consists of multiple congenital anomalies, mainly caudal segment defects. We describe a preterm baby born to a healthy mother with typical caudal regression picture, including imperforated anus with rectovesical fistula, sacral agenesis, multiple rib and vertebral anomalies, and club feet. Crossed fused renal ectopia with fused ureters resulting in urinary obstruction was managed with transureteroureterostomy and cutaneous vesicostomy. We also found a single large umbilical artery with high abdominal aortic insertion which usually presents in sirenomelia. Because of the anatomical diversity of the urinary and cardiovascular systems associated with multiple congenital anomalies, careful evaluation is mandatory.

The role of transcatheter arterial embolization for patients with unresectable hepatocellular carcinoma: a nationwide, multicentre study evaluated by cancer stage.

BACKGROUND: Transcatheter arterial embolization is a major palliative treatment for unresectable hepatocellular carcinoma, but the survival benefit of transcatheter arterial embolization is controversial. AIM: To evaluate the role of transcatheter arterial embolization in different stage of unresectable hepatocellular carcinoma and to select patients who can get the best benefit from the treatment. METHODS: From 1991 to 1995, 476 patients who had unresectable hepatocellular carcinoma from four medical centres in Taiwan were enrolled. Among them, 425 underwent transcatheter arterial embolization, and 51 received supportive treatment alone. The survivals between the two groups were compared. RESULTS: Among the 476 patients, transcatheter arterial embolization can significantly prolong survival. The 1-, 2-, and 5-year survival rates for patients who underwent transcatheter arterial embolization were 60.2%, 39.3%, and 11.5%; and the rates for patients who underwent supportive treatment were 37.3%, 17.6%, and 2%, respectively (P = 0.0002). The survival benefit of transcatheter arterial embolization was observed in patients between Cancer and the Liver Italian Program 0 and Cancer and the Liver Italian Program 4. In multivariate analysis, transcatheter arterial embolization, tumour size <5 cm and earlier Cancer and the Liver Italian Program stage were independent factors associated with a better survival. CONCLUSIONS: For patients who fulfilled the criteria of transcatheter arterial embolization, embolization can serve as a primary treatment for patients with unresectable hepatocellular carcinoma. The survival benefit of transcatheter arterial embolization is regardless of tumour stages.

Low mutation rate of hMSH2 and hMLH1 in Taiwanese hereditary non-polyposis colorectal cancer.

Hereditary non-polyposis colorectal cancer (HNPCC), the most common type of hereditary colorectal cancer, is thought to be a simple Mendelian disease involving DNA mismatch repair genes. The majority of mutations associated with HNPCC occur in the hMSH2 and hMLH1 genes. The reported incidence of mismatch repair gene mutations in HNPCC kindreds varies considerably (from 22 to 86%), and most mutations are unique. This study aimed to determine the genetic basis of Taiwanese HNPCC kindreds, focusing on the two major genes involved in this disease. A total of 15 Taiwanese HNPCC kindreds meeting the Amsterdam criteria, including 72 affected individuals among a total of 266 individuals, were analyzed using both RNA- and DNA-based methods. The mutation rate of hMSH2 and hMLH1 in these 15 kindreds was 0% and 20%, respectively, which is lower than that reported in other countries. Two novel mutations were discovered in hMLH1: one was an allelic loss of a 5.2-kb genomic fragment causing exon 16 deletion; and the other was a two-nucleotide deletion that resulted in a frameshift mutation of exon 3. We also identified one hMLH1 exon 4 mutation (a C to T transition in codon 117), which had been reported previously in western countries. This is the first genetic study of HNPCC from Taiwan.

Hypermethylation in human cancers of the RIZ1 tumor suppressor gene, a member of a histone/protein methyltransferase superfamily.

The retinoblastoma protein-interacting zinc finger gene RIZ1 is a tumor suppressor gene and a member of a nuclear histone/protein methyltransferase superfamily. RIZ1 inactivation is commonly found in many types of human cancers and occurs through loss of mRNA expression, frameshift mutation, chromosomal deletion, and missense mutation. RIZ1 is also a tumor susceptibility gene in mice. We now show that loss of RIZ1 mRNA in human cancers is associated with DNA methylation of its promoter CpG island. Methylation of the RIZ1 promoter strongly correlated with lost or decreased RIZ1 mRNA expression in breast, liver, colon, and lung cancer cell lines as well as in liver cancer tissues. Treatment with the methylation inhibitor 5-aza-2'-deoxycytidine activated RIZ1 mRNA expression in cancer cells. Furthermore, methylation was found in 11 of 25 (44%) breast cancer specimens and 20 of 32 (62%) liver cancer specimens. Our results suggest that DNA methylation is a common mechanism in inactivating the RIZ1 tumor suppressor gene in human liver and breast cancers.

Less reversal of liver fibrosis after prolonged carbon tetrachloride injection.

BACKGROUND/AIMS: It was generally believed, but not proved, that early cirrhosis may be reversible, while advanced cirrhosis may not. This present study is to compare in mice the spontaneous regression of liver fibrosis between early and more advanced stage. METHODOLOGY: Liver fibrosis in mice was induced by intraperitoneal injection of carbon tetrachloride for 4, 10, and 16 weeks. After the last dose of each schedule, mice were sacrificed 1 day later (progression model) or left untreated for 10, 20, and 60 days (regression model). Tissue sections were stained by Sirius red. Liver hydroxyproline levels were determined to assess severity of fibrosis. Gelatinases in tissue extracts were assayed by zymography. RESULTS: During regression, diminution of fibrotic bands was more prominent in the 4-week group than in the others. Liver hydroxyproline levels in the progression model increased and resolution of liver fibrosis in the regression model decreased as carbon tetrachloride injection was prolonged. Liver matrix metalloproteinase-2 and -9 activities in the progression model also decreased as the injection was prolonged. CONCLUSIONS: These data demonstrated that reversibility of liver fibrosis would be gradually lost as liver injuries were prolonged. Gradual loss of the expression of matrix metalloproteinases may be responsible for the loss of reversibility.

Expression of matrix metalloproteinases in spontaneous regression of liver fibrosis.

BACKGROUND/AIMS: Spontaneous regression of liver fibrosis would depend on the degradation of the excessive matrix in the liver. In this study, we tried to determine the kinetics of the expression of genes for matrix metalloproteinase-2 and -13. METHODOLOGY: Liver fibrosis induced by carbon tetrachloride was resolved after withdrawal of this toxin. Histological staining for fibrous septa and determination of liver collagen content were used to evaluate the extent of liver fibrosis. Expression in liver of matrix metalloproteinase-2 and -13 was determined by reverse transcription-polymerase chain reaction. RESULTS: The fibrous septa became thinner and interrupted and liver fibrosis resolved rapidly within 10 days. Expression of matrix metalloproteinase-2 and -13 was elevated to 2.5- and 8.7-fold, respectively, at peak fibrosis. The former was maintained at 88%-76% and the later dropped rapidly to 30%-20% in the recovery periods. CONCLUSIONS: Resolution of liver fibrosis began within 10 days but only to 70%. Gene expression kinetics suggested metalloproteinase-13 might play a more important role in the resolution because it surged more markedly at peak fibrosis and returned to nearly basal levels in the recovery periods in parallel with liver collagen content.

Deletion mapping of chromosome 16q24 in hepatocellular carcinoma in Taiwan and mutational analysis of the 17-beta-HSD gene localized to the region.

Human chromosome band 16q24 commonly undergoes loss of heterozygosity (LOH) in human hepatocellular carcinoma (HCC). To further localize the region of deletion on 16q24 and to evaluate the genetic role of 17-beta-HSD, which is near 16q24, in HCC, we examined the pattern of loss of heterozygosity in 88 HCC patients. DNAs from 88 pairs of HCCs and corresponding non-tumor parts were prepared. Loss of heterozygosity on chromosomes 16q24 was investigated by 11 sets of microsatellite markers. Mutation analysis of type II 17-beta-HSD was performed by automatic sequencing. LOH on 16q24 for at least 1 locus was found in 43 of the 88 tumor DNAs (49%). Three non-overlapping regions of frequent LOH were defined in these 43 tumors with partial deletions. The first region was between D16S516 loci and D16S507, encompassed by a 1-cM region, defined by the D16S504. The second region was defined by the 17HSDB2 locus between D16S505 and D16S422, encompassed approximately by a 1-cM region. The third region was between D16S520 and D16S413, defined by D16S3048, encompassed approximately by a 4-cM region. Homozygous deletions of any exons in 17HSDB2 gene were identified in 7 of 27 cases (26%). Automated sequencing analysis of 17HSDB2 failed to demonstrate mutations in any of these specimens. Our data suggest that the 17HSDB2 locus is a frequent target of deletion in HCC but the inactivation of 17HSDB2 may not involve sequence mutations. Furthermore, the presence of the other 2 frequent LOH regions suggest that the putative tumor suppressor genes at these locations might be involved in the development of HCC.

Preferential loss of a polymorphic RIZ allele in human hepatocellular carcinoma.

The RIZ (PRDM2) locus commonly undergoes loss of heterozygosity (LOH) and maps within the minimal deleted region on 1p36 in hepatocellular carcinoma (HCC). Although peptide-altering mutations of RIZ are rare in HCC, the RIZ1 product is commonly lost in HCC and has tumour suppressive activities. Here, we analysed RIZ gene mutations and LOH in HCC, breast cancer, familial melanoma, colon cancer, and stomach cancer. We found 7 polymorphisms but no mutations. By analysing the Pro704-deletion polymorphism, we detected LOH of RIZ in 31 of 79 (39%) informative HCC cases, 11 of 47 (23%) colon cancer cases, 8 of 43 (19%) breast cancer cases, 8 of 66 (12%) stomach cancer cases. Importantly, loss of the Pro704(+)allele was found in 74% of the 31 LOH positive HCC cases (P< 0.01), indicating a preferential loss and hence a stronger tumour suppressor role for this allele compared to the P704(-)allele. In addition, the Pro704(+)allele was found to be more common in Asians (0.61) than Caucasians (0.42) (P = 0.0000), suggesting an interesting link between gene polymorphisms and potential differences in tumour incidence between racial groups.

Expressions of cancer-testis antigens in human hepatocellular carcinomas.

Though regular sonographic examination can early detect small hepatocellular carcinoma, the therapeutic results remains unsatisfactory. Antigen-specific immunotherapy is an alternative approach for controlling tumors. The prerequisite for antigen-specific cancer immunotherapy is the identification of appropriate tumor antigens. Recently, a new category of tumor-specific shared antigens, called cancer-testis antigens, has been identified. The cancer-testis antigens have been found in a variety of cancers. However, the expression of cancer-testis antigens in human hepatocellular carcinomas is unknown. The aim of this current study is to investigate the expression of cancer-testis antigens in human hepatocellular carcinomas. Reverse-transcription polymerase chain reaction (RT-PCR) was used to investigate the expression of the SSX-1,-2,-4,-5, SCP-1, NY-ESO-1 genes in tumorous and corresponding non-tumorous liver tissues. In the 30 hepatocellular carcinomas studied, SSX-1,-2,-4,-5, SCP-1, and NY-ESO-1 mRNA expressions were detected in 24 (80%), 14 (46.7%), 22 (73.3%), 10 (33.3%), 2 (6.7%), and 11 (36.7%), respectively. Expressions of these genes were detected in few non-tumor liver tissues. The cancer-testis antigens are expressed in a high percentage of hepatocellular carcinomas. These cancer-testis antigen gene products are potential targets for antigen-specific immunotherapy of hepatocellular carcinoma.

Correlation of histologic subtypes and replication error phenotype with comparative genomic hybridization in gastric cancer.

To characterize phenotypic and genotypic changes in gastric cancer (GC), DNA copy number aberrations (CNAs) were assessed in 53 tumors using comparative genomic hybridization (CGH) and correlated with clinicopathologic characteristics and status of TP53 and replication error (RER). The number of CNAs per tumor was 6.8 (gain 5.3, loss 1.5), and the number of changes was significantly higher in tumors with advanced stage, TP53 mutation, and without RER than in those with early stage (7.7 vs. 3.0), no TP53 mutations (12.4 vs. 4.8) or RER phenotype (8.2 vs. 2.6). Frequent abnormalities included gains on chromosomal arms 8q (43%), 6q (26%), 11q (26%), 13q (24%), 7p (23%), 17q (23%), and 20q (23%), and losses on chromosomal arms 16q (26%), 19p (23%), 5q (19%), 3p (15%), 4q(15%), and 1p (15%). Advanced GC demonstrated a higher prevalence of gains of 8q (51% vs. 10%, P < 0.05) and loss of 16q (33% vs. 0%, P < 0.05) than early GC. Gains on 8q (64% vs. 20%, P < 0.05), 17q (39% vs. 4%, P < 0.05) and losses on 3p (25% vs. 4%, P = 0.05) and 5q (32% vs. 4%, P < 0.05) were higher in intestinal GC than in diffuse GC. On the other hand, gains on 13q were more common in the diffuse type (40% vs. 11%, P < 0.05). As compared with noncardia cancer, cardia cancer showed more gains on 7p (58% vs. 12%, P < 0.05) and 20q (58% vs. 12%, P < 0.05) and more losses on 4q (50% vs. 5%, P < 0.05). The finding of histology-related aberrations and the combination of CGH and molecular data thus provide additional evidence suggesting genetic heterogeneity of GC.

Hepatic lymphangioma--a case report.

A patient presented with a huge, pedunculated abdominal cystic lymphangioma arising from the quadrate lobe of the liver near the round ligament. Microscopically, dilated hepatic ducts with scant liver tissue could be recognized in the main cyst. A review of the literature reveals no previous report of a lymphangioma arising in this manner or from this area.

Recurrent hepatocellular carcinoma presenting with superior vena cava syndrome.

A 45-year-old male received wedge resection for his small hepatocellular carcinoma in April 1989 and extended right lobectomy for tumor recurrence 8 months later. Unfortunately, recurrent hepatic tumor with lung metastases were found 18 months after the second operation. Both the hepatic and pulmonary recurrent tumors were resected and transcatheter arterial embolization was added for the residual hepatic tumors. He remained symptom free for another 18 months. However, mediastinal lymphadenopathy, superior vena cava thrombus with superior vena cava syndrome, cardiac and brain metastases developed subsequently. He died of increased intracranial pressure. It is rare for hepatocellular carcinoma to have mediastinal metastases, superior vena cava thrombus and superior vena cava syndrome.

Segmental dilatation of the ileum as an unusual cause of gastrointestinal bleeding: report of one case.

We report a case of segmental dilatation of the ileum in a 10-month-old male infant. Intermittent loose black-colored stool passage and normocytic anemia were noted at the initial visits to our hospital. There was no symptom or sign of intestinal obstruction such as abdominal distention or vomiting. On physical examination, he was found to be pale but his abdomen was soft and flat. Digital examination revealed brownish stool tinged with black-colored oil-like stool but no polyp. Laboratory studies excluded coagulopathy, hemolytic anemia and lead poisoning. During hospitalization, he was treated with nothing per mouth, intravascular fluids, ranitidine, and transfusion of packed red blood cells. All examinations including panendoscopy, Technetium-99m (99mTc)-pertechnetate Meckel's diverticulum scan, and double contrast colon series revealed no organic lesion except that 99mTc-red blood cell bleeding scans showed abnormal bleeding in the small intestine. Because of his persistent gastrointestinal bleeding with unknown cause, we did an exploratory laparotomy when the patient was 13 months old and idiopathic segmental dilatation of the ileum was confirmed. The dilated segment is supposed to be idiopathic because of histologically proven normal muscle layers without ectopic tissue. This case suggests that segmental dilatation of the ileum can only present as gastrointestinal bleeding without intestinal obstruction.

Mapping of a minimal deleted region in human hepatocellular carcinoma to 1p36.13-p36.23 and mutational analysis of the RIZ (PRDM2) gene localized to the region.

Human chromosome band 1p36 commonly undergoes loss of heterozygosity (LOH) in hepatocellular carcinoma (HCC) but the minimal deleted region remains to be mapped. This chromosomal region contains a candidate HCC suppressor gene, RIZ (PRDM2), that is a member of the PR (PRDI-BF1-RIZ homology)-domain-containing zinc finger gene family. One characteristic of this family is the unusual yin-yang involvement in human cancers. The PR-domain-containing RIZ1 product of the RIZ locus, in contrast to the PR-domain-minus product RIZ2, is commonly lost or underexpressed in HCC. Furthermore, RIZ1 can induce cell cycle arrest, apoptosis, or both and suppress HCC tumorigenicity in nude mice. To help identify the putative HCC locus on 1p36 and to evaluate a genetic role of RIZ in HCC, we studied 97 HCC cases and mapped a minimal deleted region in HCC to 1p36.13-p36. 23 between markers D1S434 and D1S436. Notably, RIZ mapped within this region and was found to undergo LOH in 37% (25/67) of HCC cases. Single-strand conformation polymorphism (SSCP) analysis, however, did not show mutations in the PR-domain region of RIZ1 in 49 cases of HCC examined. Our data suggest that the RIZ locus is a target of frequent deletion in HCC, but that the more common way of RIZ inactivation in HCC may not involve mutations that alter peptide sequences. Genes Chromosomes Cancer 28:269-275, 2000.

Incidence and clinical presentation of posttransfusion TT virus infection in prospectively followed transfusion recipients: emphasis on its relevance to hepatitis.

BACKGROUND: A novel transfusion-transmissible human DNA virus, TT virus (TTV), has been discovered recently. An attempt was made to determine the incidence and clinical outcome of TTV infection in recipients of blood transfusion. STUDY DESIGN AND METHODS: Serial serum samples collected as part of a prospective study of posttransfusion hepatitis were examined for TTV DNA by a nested PCR assay. RESULTS: Among 150 adults undergoing cardiac surgery, posttransfusion specimens from 59 individuals were positive for TTV DNA. Pretransfusion sera were found to be positive in 13 of these individuals. Therefore, 46 (33.6%) of the 137 previously uninfected patients developed new TTV viremia after transfusion. Among the 46 patients, 3 were coinfected with HCV, 5 were coinfected with HGV, and 38 were infected with TTV alone. No apparent symptoms or signs were noted in the 38 patients infected by TTV alone or the 5 infected with HGV plus TTV. The average peak serum ALT activity was 31 IU per L, with persistently normal levels in 34 of the 38 patients with TTV infection alone. In 8 other patients who subsequently developed well-documented non-A-G hepatitis, 3 were positive for TTV (3/8 vs. 46/137, p = 0.8). In 12 patients followed for more than 1 year, TTV viremia persisted in every case. CONCLUSION: In this population, TTV is transmitted by transfusion to approximately 30 percent of patients who undergo cardiac surgery. Most of the infections appear to become persistent. Despite the high prevalence rate, TTV does not appear to cause hepatitis on its own.

Distinct clinicopathologic and genetic profiles in sporadic gastric cancer with different mutator phenotypes.

A subset of sporadic gastric cancers (GC) exhibits microsatellite instability (MSI). To define the precise role of MSI in GC, a total of 100 patients with sporadic GC were classified into three groups, i.e., high-frequency MSI (MSI-H), low-frequency MSI (MSI-L), and microsatellite stable (MSS), based on 10 microsatellite markers. Mutational analyses of TGFbetaRII, IGFIIR, BAX, MSH3, MSH6, E2F4, MSH2, MLH1, and TP53 genes, and methylation and protein expression of MLH1 and MSH2 were performed and correlated. Twenty-seven percent of GC showed MSI at least in one locus and could be further graded as MSI-H (14%) and MSI-L (13%). No clinicopathologic difference was noted between GC with MSI-L and MSS. Compared with GC with MSI-L or MSS, GC with MSI-H had a significantly higher frequency of antral location, intestinal subtype, H. pylori seropositivity, but a lower incidence of lymph node metastasis, and displayed a higher frequency of frameshift mutations of TGFbetaRII, IGFIIR, BAX, MSH3, and E2F4 genes but a lower incidence of TP53 mutations. Furthermore, hypermethylation of the MLH1 promoter was responsible for the loss of protein function in 13 of 14 MSI-H tumors. It was concluded that a specific phenotype and a distinct profile of genetic alterations exist in MSI-H GC. We speculate that epigenetic inactivation of MLH1 by methylation plays a crucial role in initiating such a pathway of carcinogenesis. In contrast, GCs with MSS and MSI-L exhibit clinicopathologic features that are distinct from MSI-H tumors and have a higher frequency of TP53 mutations, suggesting that they may evolve through an entirely different pathway.