Concomitant neoplasms in the skin and stomach unveil the role of type IV collagen and E-cadherin in mucin core protein 5AC expression in vivo.

Mucin core protein (MUC) 5AC is a gel-forming glycoprotein that is expressed in different types of tumour cells. MUC5AC expression in cultured cells is regulated through the extracellular matrix and through remodelling by other membranous proteins such as type IV collagen (COL4) and E-cadherin. However, it has not been elucidated whether COL4 and E-cadherin affect MUC5AC expression in tumours in vivo. Here, by analysing a single individual with concomitant neoplasms in the skin [extramammary Paget disease (EMPD)] and the stomach (gastric cancer), we show that MUC5AC expression is reduced in COL4 and membranous E-cadherin-expressing EMPD specimens whereas MUC5AC is not abolished in gastric cancer with COL4 negativity and E-cadherin cytoplasmic localization. As the EMPD and gastric cancer specimens were derived from a single patient, each specimen had the same genetic background. These in vivo results support previous in vitro studies which showed that COL4 and E-cadherin downregulated MUC5AC expression. Our study suggests that concomitant neoplasms in different organs of the same individual can serve as a strong tool for uncovering functional diversity in tumour markers in distinct cancer cells.

Association of CD8+ T cell infiltration in oesophageal carcinoma lesions with human leucocyte antigen (HLA) class I antigen expression and survival.

Oesophageal cancer is one of the most aggressive tumours with a poor prognosis. However, little is known about the immune response in the tumour microenvironment. To investigate the role of immunosurveillance in the clinical course of oesophageal squamous cell carcinoma, 98 formalin-fixed, paraffin-embedded primary tumours were analysed using immunohistochemical methods for human leucocyte antigen (HLA) class I heavy chain and ß2-microglobulin expression and for CD4-, CD8- and CD57-positive cell infiltration. HLA class I expression of tumour cells was correlated positively with infiltration of CD8(+) T cells into the cancer nest, but not with the clinical course of disease. However, CD8(+) and CD4(+) T cell infiltration was correlated with prognosis. These results suggest that tumour antigen-specific cellular immune response plays a role in the clinical course of the disease and that HLA class I antigen expressed on tumour cells contribute to this association most probably by mediating the interactions between tumour cells and CD8(+) T cells.

Computed tomography evaluation of regional lymph node metastases in patients with biliary cancer.

BACKGROUND: Identification of lymph node metastases in biliary cancer is important for determining prognosis and surgical planning, but the effectiveness of computed tomography (CT) in diagnosing node metastases of the hepatoduodenal ligament (peribiliary and retroportal nodes) or around the common hepatic artery is unknown. METHODS: CT scans and pathological results from 146 patients who had undergone regional lymphadenectomy for biliary carcinoma were reviewed. To evaluate the regional lymph nodes, long- and short-axis diameters of lymph nodes were measured and axial ratios calculated (short-axis diameter/long-axis diameter). Nodes were considered round if the axial ratio exceeded 0.7. Internal lymph node structures were also evaluated. RESULTS: The presence of a round node with a short-axis diameter exceeding 16 mm had a positive predictive value (PPV) of 56 per cent for the presence of metastatic foci, and node heterogeneity had a PPV of 64 per cent. The highest PPV (67 per cent) was obtained for round nodes greater than 18 mm in short-axis diameter, but nodes of this size and character were rare. CONCLUSION: CT is not useful for predicting regional lymph nodal metastases in biliary carcinoma.

HERP, a new primary target of Notch regulated by ligand binding.

Notch signaling dictates cell fate and critically influences cell proliferation, differentiation, and apoptosis in metazoans. Ligand binding initiates the signal through regulated intramembrane proteolysis of a transmembrane Notch receptor which releases the signal-transducing Notch intracellular domain (NICD). The HES/E(spl) gene family is a primary target of Notch and thus far the only known Notch effector. A newly isolated HERP family, a HES-related basic helix-loop-helix protein family, has been proposed as a potential target of Notch, based on its induction following NICD overexpression. However, NICD is physiologically maintained at an extremely low level that typically escapes detection, and therefore, nonregulated overexpression of NICD-as in transient transfection-has the potential of generating cellular responses of little physiological relevance. Indeed, a constitutively active NICD indiscriminately up-regulates expression of both HERP1 and HERP2 mRNAs. However, physiological Notch stimulation through ligand binding results in the selective induction of HERP2 but not HERP1 mRNA and causes only marginal up-regulation of HES1 mRNA. Importantly, HERP2 is an immediate target gene of Notch signaling since HERP2 mRNA expression is induced even in the absence of de novo protein synthesis. HERP2 mRNA induction is accompanied by specific expression of HERP2 protein in the nucleus. Furthermore, using RBP-Jk-deficient cells, we show that an RBP-Jk protein, a transcription factor that directly activates HES/E(spl) transcription, also is essential for HERP2 mRNA expression and that expression of exogenous RBP-Jk is sufficient to rescue HERP2 mRNA expression. These data establish that HERP2 is a novel primary target gene of Notch that, together with HES, may effect diverse biological activities of Notch.

Transcriptional targeting of adenovirus vectors with the squamous cell carcinoma-specific antigen-2 promoter for selective apoptosis induction in lung cancer.

Squamous cell carcinoma antigens SCCA1 and SCCA2 are highly homologous serine proteinase inhibitors which have been widely utilized as serological markers for squamous cell cancers, but it has recently been demonstrated that only SCCA2 is truly specific for certain forms of lung cancer. Using a construct containing the 5'-flanking region of the SCCA2 gene between -460 and +0 bp and the luciferase reporter gene, SCCA2 promoter activity was detected in SCCA2-producing SCC cell lines (LK-2, LC-1), but not in SCCA2-nonproducing lung adenocarcinoma cell lines (A549, ABC-1, and RERF-LC-MS) or normal cells (WI-38, SAEC, and NHEK-Adult). Infection with a recombinant adenovirus vector, Ad-SCCA2-DsRed, resulted in cell-specific expression of the SCCA2 promoter-driven DsRed marker gene only in LK-2 and LC-1 cells. The same strategy was used for SCCA2-driven expression of a proapoptotic gene, (KLAKLAK)2, which can cause mitochondrial disruption by triggering mitochondrial permeabilization and swelling, resulting in the release of cytochrome c and induction of apoptosis. Infection with Ad-SCCA2-KLAKLAK2 specifically reduced the growth of the two human lung SCC cell lines compared to the SCCA2 nonproducing cell lines both in vitro and in vivo, suggesting that the SCCA2 promoter had a tumor-specific effect. These results suggest that transduction of SCCA2 promoter-controlled suicide genes by adenoviral vectors can confer transcriptionally targeted cytotoxicity in SCCA2-producing lung SCC cells, and represents a novel strategy for gene transfer specifically targeted to SCC in the lung.

Selectively replicating adenoviruses for oncolytic therapy.

The most prevalent problem in cancer therapy is the regrowth and metastasis of malignant cells after standard treatment with surgery, radiation, and/or chemotherapy. Gene therapy approaches have suffered from the inadequate transduction efficiencies of replication-defective vectors that have been used thus far. Replication-competent vectors, particularly adenoviruses that cause cytolysis as part of their natural life cycle, represent an emerging technology that shows considerable promise as a novel treatment option, particularly for locally advanced or recurrent cancer. A number of oncolytic adenoviruses that are designed to replicate selectively in tumor cells by targeting molecular lesions inherent in cancer, or by incorporation of tissue-specific promoters driving the early genes that initiate viral replication, are currently being tested in clinical trials. The results of these clinical trials indicate that, in its current form, oncolytic adenovirus therapy shows the best results and achieves an enhanced tumoricidal effect when used in combination with chemotherapeutic agents such as cisplatin, leucovorin and 5-fluorouracil. Nevertheless, each of the oncolytic adenoviruses in current use exhibits characteristic shortcomings, and there is still considerable room for improvement. Current strategies for improving the selectivity and efficacy of oncolytic adenoviruses include molecular engineering of tumor cell-specific binding tropism, selective modifications of viral early genes and incorporation of cellular promoters to achieve tumor-specific replication, augmentation of anti-tumor activity by incorporation of suicide genes, and manipulation of the immune response.

Effects of diltiazem on plasma level and urinary excretion of digoxin in healthy subjects.

To evaluate a possible effect of diltiazem hydrochloride (DTZ) on digoxin (DX) kinetics, we performed a study in which a single oral dose of DX (0.5 or 0.75 mg) was given with and without DTZ (30 mg three times daily for 1 wk) to six healthy subjects. DTZ increased plasma DX concentrations at 3, 4, 6, and 12 hr and decreased renal clearance of DX from 3.05 +/- 0.126 to 2.31 +/- 0.234 ml/min/kg. There was no significant change in absorption t 1/2, peak concentration, peak concentration time, distribution t 1/2, biologic elimination t 1/2, or apparent volume of distribution with DTZ.

Development of lentiviral vectors for antiangiogenic gene delivery.

Growth and metastasis of malignant tumors requires angiogenesis. Inhibition of tumor-induced angiogenesis may represent an effective cytostatic strategy. We have constructed recombinant self-inactivating lentiviral vectors expressing angiostatin and endostatin, and have tested their antiangiogenic activities. As VSV-G-pseudotyped lentiviral vectors showed low relative transduction titers on bovine aortic and human umbilical vein endothelial cells, it was difficult to achieve significant inhibition of endothelial cell growth by lentivirus-mediated antiangiogenic gene transfer directly to endothelial cells without concomitant vector-associated cytotoxicity. However, lentivirus vectors could efficiently and stably transduce T24 human bladder cancer cells that are relatively resistant to adenovirus infection due to loss of coxsackievirus-adenovirus receptor expression. Long-term expression and secretion of angiostatin and endostatin from lentivirus-transduced T24 cells resulted in significant inhibition of cellular proliferation on coculture with endothelial cells. This report represents the first use of lentivirus-based vectors to deliver the antiangiogenic factors, angiostatin and endostatin, and suggests the potential utility of antiangiogenic gene therapy with lentiviral vectors for the treatment of cancer.

Efficacy of the electrothermal bipolar vessel sealer in laparoscopic spleen-preserving distal pancreatectomy with conservation of the splenic artery and vein.

INTRODUCTION: Laparoscopic spleen-preserving distal pancreatectomy (LSPDP) with conservation of the splenic artery and vein has recently been performed as a minimally invasive surgery to retain splenic function in the treatment of pancreatic diseases. As the branches of the splenic vessels are very delicate, division of these branches increases the risk of bleeding. MATERIALS AND METHODS: To overcome this problem, we have used the electrothermal bipolar vessel sealer (EBVS) to divide branches of the splenic vessels in LSPDP while conserving the splenic vessels themselves. RESULTS: The EBVS reliably provided excellent and safe hemostasis, minimizing the risk of serious blood loss. CONCLUSION: Use of the EBVS is safe and efficient in LSPDP with conservation of the splenic vessels.