ABSTRACT
Negative ions are considered to have potential health benefits, but few studies have examined their effects in vivo. We studied water-generated negative ions (WNI) with respect to physical properties as well as immunologic activation and anti-tumor activity (inhibition of carcinogenesis and tumor growth) in mice. Electrically, generated negative ions (ENI) served as control. Water-generated negative ions had a long life, significantly enhanced the cytotoxic activity of natural killer cells, and significantly decreased the incidence of cancer and inhibited tumor growth. Anti-tumor effects were attributed to enhancement of natural killer cell activity. The mechanisms and applications of negative ions warrant further investigation.
Subject(s)
Anions , Cell Transformation, Neoplastic/immunology , Killer Cells, Natural/immunology , Water , Animals , MiceABSTRACT
There have been few studies regarding cancer progression from differentiated thyroid carcinoma to the undifferentiated one. To examine the possible involvement of Epstein-Barr virus (EBV) in this progression, 10 papillary carcinomas and 11 undifferentiated carcinomas were subjected to mRNA in situ hybridization, indirect immunofluorescence staining, polymerase chain reaction (PCR), and reverse-transcriptase PCR. mRNA in situ hybridization using a BamHIW probe revealed signals in all of the examined samples, although the signal strength was weaker in the papillary carcinomas than in the undifferentiated carcinomas. EBV nuclear antigen-2 (EBNA2) in situ hybridization produced almost the same results; however, the signals were detected less frequently in the papillary carcinomas. Indirect immunofluorescence using anti-EBNA2, anti-latent membrane protein-1 (LMP1), and anti-BZLF1 antibodies also showed positive results with high frequency and with more prominent fluorescence in undifferentiated carcinomas than in papillary carcinomas. An examination of thyroid carcinoma cell lines also confirmed these findings. EBV infected all of the thyroid carcinomas irrespective of the degree of pathological differentiation. The expression of EBV, especially of EBNA2 and LMP1 (both of which are oncogene products of EBV), was stronger in the undifferentiated carcinomas than in the papillary carcinomas. These results suggest that increased expression of EBV may be involved in the progression of thyroid papillary carcinoma to undifferentiated carcinoma.
Subject(s)
Carcinoma, Papillary/virology , Epstein-Barr Virus Infections/complications , Thyroid Neoplasms/virology , Animals , Blotting, Southern , DNA, Viral/analysis , Disease Progression , Epstein-Barr Virus Nuclear Antigens/metabolism , Fluorescent Antibody Technique , Herpesvirus 4, Human/isolation & purification , Humans , In Situ Hybridization , RNA, Messenger/analysis , Reverse Transcriptase Polymerase Chain Reaction , Viral Matrix Proteins/metabolismABSTRACT
BACKGROUND: The anti-tumor activity of interferon-gamma (IFN-gamma) and interleukin-2 (IL-2) have been shown in human gastric cancer cell lines, however, their therapeutic effects on peritoneal metastasis have not been investigated. MATERIALS AND METHODS: The anti-tumor activity of IFN-gamma and IL-2 against the gastric cancer cell line, MKN45, was evaluated by in vitro antiproliferation assays and in animal-tumor models of intraperitoneal (i.p.) and subcutaneous (s.c.) tumors. RESULTS: Survival of the animals with i.p. tumor was longest in those given IFN-gamma, followed by those given IL-2, IL-2 + IFN-gamma and saline (control) with median survival of 88 +/- 27 days, 73 +/- 30 days, 53 +/- 20 days and 32 +/- 1.1 days, respectively (p < 0.001 vs control). In animals with s.c. tumor, IFN-gamma significantly inhibited tumor growth as compared with the control. In vitro, IFN-gamma alone inhibited the growth of MKN45 and induced apoptosis, while IL-2 had no additional effect. CONCLUSION: IFN-gamma inhibited the growth of gastric cancer cells in vitro and in a peritoneal tumor model. The therapeutic effects were partially antagonized by IL-2.
