Growth and Chemosensitivity of Gastric Adenocarcinoma and Non-Malignant Cell Lines in Response to Novel Anti-Cancer Drug Combinations.

BACKGROUND: To design novel polychemotherapy regimens for gastric adenocarcinoma therapy with wider therapeutic windows using a novel duplex drug (D-D). METHODS: Two gastric adenocarcinoma (MKN-45 and 23132/87) and 2 non-malignant (NHDF and CCL-241) cell lines were treated with different drug regimens that included different doses of the standard triple-drug combination epirubicin (E) + cisplatin (C) + 5-fluorouracil (5-FU, F), i.e. ECF, and a new D-D that combined 2'-deoxy-5-fluorouridine (5FdU) and 3'ethinylcytidine. The cells were cultured for 14 days and the effect of the drug combinations was evaluated using CASY cell counting technology. RESULTS: Overall growth inhibition of the cell lines with ECF was not cancer cell line-specific. Replacing 5-FU in ECF with a D-D resulted in greater growth inhibition of cancer cells than of the non-malignant cell lines and the inversion of the chemosensitivity of MKN-45 and 23132/87 cells. The type and quantity of the combined drug regimen determined the cytotoxicity and chemosensitivity of the cell lines. CONCLUSION: The cytotoxicity and tumour-cell specificity of standard single drugs can be markedly changed and determined using multidrug combinations that include D-Ds.

Induction of tumor stem cell differentiation--novel strategy to overcome therapy resistance in gastric cancer.

PURPOSE: Metastases are a frequent finding in gastric cancer and are associated with poor prognosis. A recently discovered link between metabolic changes, differentiation, and therapy resistance due to tumor stem cells could depict a novel approach in cancer research and therapy. Phosphoglycerate kinase 1 (PGK1) is a metabolic enzyme and is known to be involved in enabling gastric cancer cells to be invasive and to disseminate. In this study, we investigated if PGK1 is a promising candidate in inducing stem cell differentiation in gastric cancer. MATERIALS AND METHODS: MKN45 gastric cancer cells were used due to their known cancer stem cell population, which is defined by the surface marker CD44. MKN45 cells were separated between CD44+ and CD44- cells and, in equal parts, incubated with shRNA anti-PGK1 using fluorescence-activated cell sorting (FACS) analysis; they were then injected into nude mice to evaluate their tumor growth behavior in vivo. Further, the invasive potential of gastric cancer cells was evaluated in vitro using the xCelligence analyzing system. RESULTS: CD44+ gastric cancer cells treated with and without shRNA anti-PGK1 were capable to cause tumor growth in vivo, whereas tumor growth in CD44+ cells treated with shRNA anti-PGK1 was considerably smaller in comparison with that in CD44+ cells without treatment. CD44- cells did not show any noticeable tumor growth in vivo. By targeting PGK1, the invasive potential of gastric cancer cells was impressively reduced in vitro. In all our cells, which were targeted with shRNA anti-PGK1, we did not find any change that is in accordance with the phenotype of the cells using FACS analysis. CONCLUSIONS: Our findings suggest that targeting the key metabolic enzyme PGK1 in gastric cancer cells may open a new chapter in cancer treatment, which is well worth for further exploration in combination with recent chemotherapy, and might be a promising possibility to overcome therapy resistance in gastric cancer.

Gastric Ulcer Complications after the Introduction of Proton Pump Inhibitors into Clinical Routine: 20-Year Experience.

BACKGROUND: The aim of this study was to analyze the admissions and the management of peptic ulcer disease (PUD) in a tertiary care surgical center. METHODS: We evaluated the medical records of all patients admitted to the University Hospital of Tübingen, Germany, for treatment of PUD during 1989-2008. Patients were included into the study if the diagnosis was verified endoscopically or surgically. Annual number of admissions, length of hospitalization, mortality rate, age, rate of non-steroidal anti-inflammatory drugs (NSAIDs) and proton pump inhibitor (PPI) medication, rate of Helicobacter pylori infection, and complications of PUD and surgery performed were recorded. Data were analyzed by descriptive analyses, Pearson's chi-square test, and regression analysis. RESULTS: This study included 614 admissions. The number of annual admissions (31 ± 12), the length of hospitalization (9 ± 3 days), and the mortality rate (5 ± 4% per year) remained constant, whereas the age increased (1989: 52 ± 14 years vs. 2008: 67 ± 16 years). The rates of patients with H. pylori infection (47 ± 28% per year), NSAIDs treatment (29 ± 15% per year), and PPI treatment (31 ± 27% per year) remained constant. The most frequent PUD complication was hemorrhage (42 ± 16% per year), followed by perforation (9 ± 8% per year). During 1999-2008, more hemorrhages (125 vs. 121; p < 0.05) and perforations (40 vs. 21; p < 0.05) were registered than during 1989-1998. The rate of emergency surgery increased from 70% during 1989-1998 to 87% during 1999-2008. In contrast, elective surgery decreased from 21% during 1989-1998 to 7% during 1999-2008. Ulcer excision and oversewing was the most frequent surgical procedure performed (59%), with decreasing rates of acid-reducing surgery. CONCLUSION: Despite recent advances in PUD management, ulcer hemorrhage and perforation remain a significant health burden and a surgical disease.

Phosphoglycerate kinase 1 as a promoter of metastasis in colon cancer.

Oxidative stress due to intratumoral hypoxia in solid cancer has been shown to be associated with increased mortality. Phosphoglycerate kinase 1 (PGK1) is an enzyme of the glycolytic pathway, which is regulated by hypoxia-inducible factor-1α (HIF-1α) and has been described for its role in tumor progression and metastasis in several malignancies. We investigated whether the expression of PGK1 varies between metastatic and non-metastatic colon cancer. We compared PGK1 expression in colon cancer patients either with or without metastasis via polymerase chain reaction (PCR) and immunohistochemistry. Microarray analysis was performed to test altered gene expression after PGK1 silencing, using isolates from HCT116 cell lines. PCR results showed an increased expression of PGK1 in colon cancer tissue from metastatic patients in comparison to patients with no metastasis (fold change 2.6, p<0.001). Immunohistochemical staining of PGK1 showed stronger staining in metastatic tissue in comparison to non-metastatic cancer tissue according to a semi-quantitative evaluation. Microarray and subsequent pathway analysis provided 4 genes of interest (CYR61, FOS, JUN and EGR1) used for pathway proposal. The results indicate that increased expression of PGK1 in colon cancer tissue is associated with metastasis. Furthermore, we propose several genes induced by PGK1 that could account for cell migration, mainly EGR1 and CYR61 together with the transcription factors FOS and JUN.