Competitive polymerase chain reaction: a new method for measuring N-myc amplification

The highly variable biological behaviour of neuroblastoma, a neoplasm which belongs to the family of primitive neuroectodermal tumours, is determined by its molecular pathological characteristics. Among them amplification of the N-myc gene is the most important factor in both therapeutic and prognostic points of view. Value of the amplification can be determined by different methods. The latest of them is the competitive polymerase chain reaction (PCR), essence of which is the parallel reaction of the target N-myc gene (exon 3.) and the endogen competitor CF gene (exon 3.) in the same reaction solution. The authors applied the method on 11 neuroblastoma cases diagnosed between 1994 and january of 1999. In three cases the amplification was determined also by fluorescens in situ hybridization (FISH). Six of the 11 cases were detected to have more than 10-fold, two of the six about 100-fold N-myc amplification. Results of the PCR and FISH correlated well. The two methods applied by the authors complete each other and are appropriate for determining the gene amplification which gives valuable prognostic and therapeutic information about the examined tumour.     

An analysis of serum interleukin-6 levels to predict benefits of medroxyprogesterone acetate in advanced or recurrent breast cancer

Treatment of advanced or recurrent breast cancer with medroxyprogesterone acetate (MPA) shows high response rates and the accessory effects of appetite stimulation, improvement in performance status (PS) and bone marrow protection. In recent years, interleukin-6 (IL-6) has been reported to cause cachexia. In this study, to clarify the significance of IL-6 in advanced or recurrent breast cancer, the relationship between the IL-6 level and clinical findings or effect of MPA was investigated. Sixty-five patients with recurrent or advanced breast cancer participated in a prospective study. The age of patients ranged from 28 to 79 years with an average age of 51.3 years. IL-6 level was investigated in these patients dosed with 800 mg/day of MPA and in 17 postoperative nonrecurrent patients. Serum MPA level was measured by high-performance liquid chromatography and IL-6 level was measured prior to MPA administration, 4 weeks (in 59 cases) and 12 weeks (in 32 patients) after MPA administration by ELISA. Serum IL-6 level was significantly higher in recurrent cases, especially in those with visceral metastasis. Further, in patients for whom MPA therapy was effective, the IL-6 level prior to the treatment was clearly low. The IL-6 level was significantly increased after 4 weeks. However, response to MPA was significantly higher and PS was improved in those cases demonstrating less increased IL-6 levels after 4 weeks. In addition, the effect of MPA was significantly related to a higher serum concentration of MPA-positive ER, and longer disease-free interval, although there was no significant predictive factor for the clinical effect of MPA therapy in multivariate analysis. In conclusion, MPA therapy was effective in cases demonstrating a low IL-6 level and less increased IL-6 levels after 4 weeks. PS was improved in those cases in which the degree of IL-6 increase was suppressed by MPA, and many such cases showed low IL-6 levels prior to MPA therapy. Furthermore, PS was improved even in nonresponders to MPA. Therefore, it is suggested that MPA therapy might be useful in treating recurrent breast cancer, and its benefits might be mediated by IL-6.     

Establishment of a new human pancreatic cancer cell line, NOR-P1, with high angiogenic activity and metastatic potential

We present here a new cell line, NOR-P1, established from a metastatic subcutaneous tumor of a patient with pancreatic cancer. The cells show rapid growth in culture with a doubling time of 16 h and high migration activity. Genetic and molecular analyses revealed high telomerase activity and a mutation in the K-ras oncogene. Of particular interest, the cells express markedly elevated mRNA levels of angiogenic factors, vascular endothelial growth factor and platelet-derived growth factor, as well as other tumor growth-related factors. Subcutaneous transplantation of the NOR-P1 cells into nude mice formed solid, hemorrhagic tumors which were histologically diagnosed as adenocarcinoma with dense blood vessels and severe extravasation of blood. Furthermore, when NOR-P1 cell suspension was injected directly into the pancreas of nude mice, the cells grew rapidly to form intra-pancreatic tumors associated with liver metastases and peritoneal dissemination that resulted in cachexia and subsequent death. These properties suggest that NOR-P1 is an aggressive pancreatic cancer cell line with a high metastatic potential and may serve as a useful experimental model for studying tumor angiogenesis and metastasis of pancreatic cancer.     

A possible role for centrosome overduplication in radiation-induced cell death

Radiotherapy plays a key role in the treatment of many tumors; however, the precise mechanisms responsible for radiation-induced cell death remain uncertain. We have reported previously that ionizing radiation induces centrosome overduplication in human tumor cells. The present study was designed to elucidate a possible link between centrosome dysregulation and radiation-induced cell death. Exposure to 10 Gy gamma-radiation resulted in a substantial increase in cells containing an abnormally high number of centrosomes in a variety of cell lines derived from different types of human solid tumors. These aberrant centrosomes contribute to the assembly of multipolar spindles, thereby causing an unbalanced division of chromosomes and mitotic cell death characterized by the appearance of multi- or micronucleated cells. An extensive analysis of a panel of 10 tumor cell lines revealed a positive correlation between the fraction of cells with multiple centrosomes and the fraction with these nuclear abnormalities after irradiation. When the centrosome overduplication was blocked by enforced expression of p21Waf1/Cip1, the radiation-induced lethality was drastically rescued. Taken together, these results indicate that centrosome overduplication may be a critical event leading to mitotic failure and subsequent cell death following exposure to ionizing radiation.     

An intestinal volvulus caused by multiple magnet ingestion: an unexpected risk in children

It has been reported that ingested magnets can cause intestinal fistula formation or perforation, leading to intestinal obstruction. However, there are no previous case reports that magnet ingestion additionally caused an intestinal volvulus. We report herein the case of a 1-year-old boy in whom the ingested magnets caused a volvulus of part of the small intestine leading to the resection of the necrotic portion. We think that if more than one magnet is found as a foreign body in the intestine, they should be removed immediately by laparotomy. Clinicians who care for children should be aware of this unexpected risk.     

Differentiation effects by the combination of spheroid formation and sodium butyrate treatment in human hepatoblastoma cell line (Hep G2): a possible cell source for hybrid artificial liver

The aim of this study was to investigate the feasibility of human hepatoblastoma cell line (Hep G2), which differentiates by spheroid formation, and treatment with sodium butyrate (SB) as a cell source for hybrid artificial liver (HAL). Hep G2 spontaneously formed spheroids in polyurethane foam (PUF) within 3 days of culture and restored weak ammonia removal activity. Treatment with SB, which is a histone deacetylase inhibitor, further increased the ammonia removal activity of Hep G2 spheroids in a concentration-dependent manner. The activation of ornithine transcarbamylase--a urea cycle enzyme--was significantly related to the upregulation of ammonia removal by spheroid formation, but scarcely contributed to the further upregulation following SB treatment. In contrast with ammonia removal, treatment with SB reduced the albumin secretion of Hep G2 spheroids in a concentration-dependent manner. In the PUF-HAL module in a circulation culture, the ammonia removal rate and albumin secretion rate (per unit volume of the module) of Hep G2 spheroids treated with 5 mM SB were almost the same as those of primary porcine hepatocyte spheroids. These results suggest that simultaneous use of spheroid formation and SB treatment in Hep G2 is beneficial in enhancing the functions of human hepatocytes with potential applications in regenerative medicine and drug screening.     

Laparoscopic pancreatic surgery: Current indications and surgical results

Background: Although minimally invasive surgery has achieved worldwide acceptance in various fields, laparoscopic surgery for pancreatic diseases has been reported only rarely. The purpose of this study was to evaluate the outcomes and feasibility of laparoscopic pancreatic surgery. Methods: Fifteen patients, comprising eight men and seven women with an average age of 54 years, underwent laparoscopic pancreatic surgery. Distal pancreatectomy was indicated for solid tumors (n = 4), cystic lesions (n = 3), and chronic pancreatitis (n = 2). Cystogastrostomy was performed for pseudocysts (n = 4) and enucleation for insulinomas (n = 2). The lesions varied in size from 1 to 9 cm (2.9 ± 2.4 cm) and were located in the pancreatic head (n = 2), body (n = 3), or tail (n = 10). For distal pancreatectomy, the splenic artery was divided and the parenchyma was transected with a linear stapler. Laparoscopic ultrasonography was used to determine the distance between the tumor and the main pancreatic duct for enucleation as well as to localize the lesion for distal pancreatectomy. Cystogastrostomy, 4.5 cm in length, was also performed with the linear stapler through the window of the lesser omentum. Results: Mean operation time was 249 ± 70 min (293 ± 58 min in distal pancreatectomy, 185 ± 14 min in enucleation, 204 ± 50 min in cystogastrostomy), and mean blood loss was 138 ± 184 g (213 ± 227 g, 75 ± 35 g, 38 ± 48 g, respectively). Two distal pancreatectomies (13%) were converted to open surgery due to severe peripancreatic inflammation. There was no related mortality, but there were two cases (15%) of pancreatic fistula, one in a distal pancreatectomy case and the other in an enucleation case, and both were treated conservatively. Conclusions: Laparoscopic pancreatic surgery is safe and feasible for patients with benign tumors and cystic lesions.     

Population Pharmacokinetic Modeling of a Subcutaneous Depot for GnRH Antagonist Degarelix

PURPOSE: The objective of this study is to develop a population pharmacokinetic (PK) model that describes the subcutaneous (SC) depot formation of gonadotropin-releasing hormone (GnRH) antagonist degarelix, which is being developed for treatment of prostate cancer, exhibiting dose-volume and dose-concentration dependent absorption. METHODS: The PK analysis is made in NONMEM through joint analysis of data from two phase I clinical studies; an intravenous infusion study and a single SC dose escalation study. The SC absorption is modeled using an approximation to Ficks' second law of diffusion out of a spherical depot. The dose-volume effect on the SC release is estimated using a B-spline basis whereas the bioavailability is modeled as a function of the dose-concentration. RESULTS: The SC depot model is approximated by using two concentric spherical compartments for the SC absorption combined with a two-compartment disposition model. The results indicate that the volume effect is most apparent at low injection volumes whereas the effect is diminishing at higher injection volumes. The dose-concentration effect on the bioavailability is estimated to decrease at increasing dose-concentrations. CONCLUSIONS: The presented SC depot model describes the PK profile of GnRH antagonist degarelix. This modeling approach might also be applicable for other depot-formulated drugs exhibiting complex PK profiles.     

Three-dimensional coculture of endometrial cancer cells and fibroblasts in human placenta derived collagen sponges and expression matrix metalloproteinases in these cells

OBJECTIVE: Collagen gel constitutes a valuable tool for the study of cell-matrix interactions; however, it is sometimes difficult to use the gel, in which tumor and stromal cells are cocultured, for immunohistochemistry, because it is easily broken during the process of fixation and embedding in paraffin, especially after long-term culture. METHODS: To examine the interaction between endometrial cancer cells and fibroblasts in tumor invasion, we carried out three-dimensional (3-D) coculture of various endometrial cancer cell lines and fibroblasts in human placenta derived collagen sponges and analyzed the expression and localization of matrix metalloproteinases (MMP) and plasminogen activators (PA) in these cells by immunohistochemistry. RESULTS: After 4 weeks of culture on the collagen sponges, endometrial cancer cells composed stratiform or glandular structures on the layer of extracellular matrix, which was composed from fibloblasts and extracellular matrix. Compared to Ishikawa cells, which were rarely invasive, HEC-1A and HEC-1BE and cocultured fibroblasts showed high invasiveness and strong expression of some proteins. In cell line HEC-1BE, MMP-1, -7, and -9, MT1-MMP, tissue inhibitors of metalloproteinases 2, and uPA showed intensive staining in both cancer cells and fibroblasts by immunohistochemistry. HEC-1A cells and cocultured fibroblasts showed expression patterns similar to those of HEC-1BE. CONCLUSION: These results suggested that expression of MMPs and uPA was accelerated in fibroblasts surrounded by cancer cells. We believe that our 3-D coculture system has merit in that the interaction between cancer cells and stromal cells can be visually analyzed by immunohistochemistry and that experiments for a long period, at least 2 weeks, are possible. Furthermore, it is expected that some animal, e.g., nude mouse, experiments can be replaced by experiments using this culture system.