Malignant Gastrointestinal Stromal Tumor of the Gallbladder

Gastrointestinal stromal tumors (GISTs) of the gallbladder are representative of an extremely rare group of tumors. We have encountered a patient with a malignant GIST of the gallbladder and presented it with a review of some articles. A 72-yr-old woman initially presented with right upper quadrant abdominal pain, fever and chills. Emergency cholecystectomy was performed under the impression of gallbladder empyema. Liver metastasis was found at 7 months postoperatively and the patient expired 9 months after the surgery. At the time of cholecystectomy, the gallbladder showed a necrotic serosal surface with an irregular thickened wall. A mass, 6 cm in length and 3 cm in width, encircled the whole wall of the neck and upper body of the gallbladder. Microscopic findings revealed frequent mitotic figures (more than 20/50 HPF) and tumor necrosis. Hyperchromatic, pleomorphic and spindle shaped neoplastic cells that were arranged in a pattern of short fascicles infiltrated the entire layer of the gallbladder. The tumor cells were immunoreactive for CD117 antigen (c-kit protein) and vimentin. They were negative for desmin, smooth muscle actin and S-100 protein. Mutations of the c-kit proto-oncogene were not found in this case. These findings were sufficient to provide enough clinical, histopathological and immunohistochemicalevidence in diagnosing our case as a malignant GIST

Relationship Between the Extent of Chromosomal Losses and the Pattern of CpG Methylation in Gastric Carcinomas

The extent of unilateral chromosomal losses and the presence of microsatellite instability (MSI) have been classified into high-risk (high- and baseline-level loss) and low-risk (low-level loss and MSI) stem-line genotypes in gastric carcinomas. A unilateral genome-dosage reduction might stimulate compensation mechanism, which maintains the genomic dosage via CpG hypomethylation. A total of 120 tumor sites from 40 gastric carcinomas were examined by chromosomal loss analysis using 40 microsatellite markers on 8 chromosomes and methylation analysis in the 13 CpG (island/non-island) regions near the 10 genes using the bisulfite-modified DNAs. The high-level-loss tumor (four or more losses) showed a tendency toward unmethylation in the Maspin, CAGE, MAGE-A2 and RABGEF1 genes, and the other microsatellite-genotype (three or fewer losses and MSI) toward methylation in the p16, hMLH1, RASSF1A, and Cyclin D2 genes (p<0.05). The non-island CpGs of the p16 and hMLH1 genes were hypomethylated in the high-level-loss and hypermethylated in the non-high-level-loss sites (p<0.05). Consequently, hypomethylation changes were related to a high-level loss, whereas the hypermethylation changes were accompanied by a baseline-level loss, a low-level loss, or a MSI. This indicates that hypomethylation compensates the chromosomal losses in the process of tumor progression

The overmethylated genes in Helicobacter pylori-infected gastric mucosa are demethylated in gastric cancers

<p>Abstract</p> <p>Background</p> <p>The transitional-CpG sites between weakly methylated genes and densely methylated retroelements are overmethylated in the gastric mucosa infected with <it>Helicobacter pylori </it>(<it>H. pylori</it>) and they are undermethylated in the gastric cancers depending on the level of loss of heterozygosity (LOH) events. This study delineated the transitional-CpG methylation patterns of CpG-island-containing and -lacking genes in view of the retroelements.</p> <p>Methods</p> <p>The transitional-CpG sites of eight CpG-island-containing genes and six CpG-island-lacking genes were semi-quantitatively examined by performing radioisotope-labelling methylation-specific PCR under stringent conditions. The level of LOH in the gastric cancers was estimated using the 40 microsatellite markers on eight cancer-associated chromosomes. Each gene was scored as overmethylated or undermethylated based on an intermediate level of transitional-CpG methylation common in the <it>H. pylori</it>-negative gastric mucosa.</p> <p>Results</p> <p>The eight CpG-island genes examined were overmethylated depending on the proximity to the nearest retroelement in the <it>H. pylori</it>-positive gastric mucosa. The six CpG-island-lacking genes were similarly methylated in the <it>H. pylori</it>-positive and -negative gastric mucosa. In the gastric cancers, long transitional-CpG segments of the CpG-island genes distant from the retroelements remained overmethylated, whereas the overmethylation of short transitional-CpG segments close to the retroelements was not significant. Both the CpG-island-containing and -lacking genes tended to be decreasingly methylated in a LOH-level-dependent manner.</p> <p>Conclusions</p> <p>The overmethylated genes under the influence of retroelement methylation in the <it>H. pylori</it>-infected stomach are demethylated in the gastric cancers influenced by LOH.</p

Sublingual Immunization with M2-Based Vaccine Induces Broad Protective Immunity against Influenza

The ectodomain of matrix protein 2 (M2e) of influenza A virus is a rationale target antigen candidate for the development of a universal vaccine against influenza as M2e undergoes little sequence variation amongst human influenza A strains. Vaccine-induced M2e-specific antibodies (Abs) have been shown to display significant cross-protective activity in animal models. M2e-based vaccine constructs have been shown to be more protective when administered by the intranasal (i.n.) route than after parenteral injection. However, i.n. administration of vaccines poses rare but serious safety issues associated with retrograde passage of inhaled antigens and adjuvants through the olfactory epithelium. In this study, we examined whether the sublingual (s.l.) route could serve as a safe and effective alternative mucosal delivery route for administering a prototype M2e-based vaccine. The mechanism whereby s.l. immunization with M2e vaccine candidate induces broad protection against infection with different influenza virus subtypes was explored.A recombinant M2 protein with three tandem copies of the M2e (3M2eC) was expressed in Escherichia coli. Parenteral immunizations of mice with 3M2eC induced high levels of M2e-specific serum Abs but failed to provide complete protection against lethal challenge with influenza virus. In contrast, s.l. immunization with 3M2eC was superior for inducing protection in mice. In the latter animals, protection was associated with specific Ab responses in the lungs.The results demonstrate that s.l. immunization with 3M2eC vaccine induced airway mucosal immune responses along with broad cross-protective immunity to influenza. These findings may contribute to the understanding of the M2-based vaccine approach to control epidemic and pandemic influenza infections

Effect of p53 gene transfer on the cell proliferation and cell cycle progression in a human oral cancer cell line with p53 mutation

To investigate the effect of p53 gene transfer on the cell proliferation and cell cycle progression in an oral cancer cell line containing p53 mutation, we introduced a recombinant plasmid (pMSG-p53X) encoding wt p53 into SCC-9 line. A stable clonal cell line, SCC-9-p53X, was derived that conditionally expressed wt p53 protein following exposure to dexamethasone. Induction of wt p53 expression may play an improtant role in the suppression of tumorigenic phenotypes in cancer cells with p53 mutations by decreased expression and/or activities of key G_1-phase cell cycle regulatory proteins. To investigate this possibility, we determined the change of tumorigenic phenotype, the cellular levels of key G_1-phase cell cycle regulatory proteins p21^WAF1/CIP, p16, p27, cyclins (D1 and E), cdks (cdk2, cdk4 and cdk6) and PCNA proteins, and the activities of cdks in the SCC-9-p53X cells caused (i) a significant decrease in the cell proliferation, level of the DNA replication protein, PCNA, and anchorage-independent growth, (ii) an inhibition in the activities of cdk2, cdk4, and cdk6 kinases, and(iii) a decrease in the levels of cdk2 and cdk6 proteins. However, dexamethasone failed to induce these changes in the nontransfected SCC-9 cells. These results demonstrate that in human cancer cells containing p53 mutation, the levels of cdk proteins and their kinase activities of the G_1 phase are notably reduced by expression of wt p53 gene thereby making them to repress of tumorigenic phenotype.This study was supported by the Academic Research Fund of Ministry of Education, Republic of Korea(1996, 1997)(B.-M. M.)

Metastatic breast cancer from a hepatocellular carcinoma: a case report

Breast metastases from extramammary malignancies are rare. Here, we report a case of breast metastasis from hepatocellular carcinoma (HCC) after breast mass excision in a 63-year-old woman. A new breast nodule was noticed after transarterial chemoembolization, transarterial radioembolization, and stereotactic body radiation therapy for HCC. Breast ultrasound and core needle biopsy were performed to differentiate between the breast tumors. The biopsy result was invasive breast carcinoma, and wide excision of the breast was performed. The final pathological diagnosis was HCC breast metastasis based on histological findings and immunohistochemical staining results. After 9 months of follow-up, HCC and breast metastasis recurred. Despite palliative treatment, the patient died due to complications and general health deterioration. Although breast metastasis due to HCC is very rare, HCC breast metastasis should be considered when a new breast mass is discovered in a patient with a history of HCC for effective treatment and management