Growth of Hodgkin cell lines in severely combined immunodeficient mice.

No animal model exists for the in vivo growth of Hodgkin's-lymphoma-derived cells. Neither unmanipulated Hodgkin's-disease(HD)-derived cell lines nor primary biopsy tissue could be grown in nude mice. Since the severe combined immunodeficient (SCID) mouse has been reported to be a better recipient for transplanted human lymphatic tissue than the nude mouse, we tested whether SCID mice provide suitable conditions for the in vivo growth of HD cell lines. Tumorigenicity of HD cells was tested in untreated and pre-treated SCID mice and in another combined immunodeficient mouse strain, beige/nude/X-linked immunodeficient (BNX) mouse. SCID mice supported in vivo growth of the 6 HD cell lines tested (L428, L540, L591, DEV, HD-LM2, KM-H2). Only one of the 6 lines (DEV) was tumorigenic in BNX mice. No HD cell line proliferated in T-cell-deficient nude mice. Thus, in vivo growth of HD cell lines appeared to be related to the degree of host immunodeficiency. Additional growth supportive treatments such as fibrosarcoma co-transplantation, intraperitoneal mineral oil injection or immunosuppressive pre-treatment (anti-asialo-GMI-antibody injection) permitted growth of 3 additional HD cell lines in BNX mice. The immunophenotype and karyotype of explanted graft cells were identical to the original cell lines. Our experiments describe an effective and reproducible xenograft model for growth of Hodgkin's-disease-derived cell lines. This may be of value for elucidating the growth characteristics of Hodgkin's-lymphoma-derived cells as well as for testing new therapeutic regimens.     

The product of the imprinted H19 gene is an oncofetal RNA.

AIMS/BACKGROUND: The H19 gene is an imprinted, maternally expressed gene in humans. It is tightly linked and coregulated with the imprinted, paternally expressed gene of insulin-like growth factor 2. The H19 gene product is not translated into protein and functions as an RNA molecule. Although its role has been investigated for more than a decade, its biological function is still not understood fully. H19 is abundantly expressed in many tissues from early stages of embryogenesis through fetal life, and is down regulated postnatally. It is also expressed in certain childhood and adult tumours. This study was designed to screen the expression of H19 in human cancer and its relation to the expression of H19 in the fetus. METHODS: Using in situ hybridisation with a [35S] labelled probe, H19 mRNA was detected in paraffin wax sections of fetal tissues from the first and second trimesters of pregnancy and of a large array of human adult and childhood tumours arising from these tissues. RESULTS: The H19 gene is expressed in tumours arising from tissues which express this gene in fetal life. Its expression in the fetus and in cancer is closely linked with tissue differentiation. CONCLUSIONS: Based on these and previous data, H19 is neither a tumour suppressor gene nor an oncogene. Its product is an oncofetal RNA. The potential use of this RNA as a tumour marker should be evaluated.     

Preclinical study on gene therapy of cervical carcinoma using adeno-associated virus vectors

Approximately 90% of cervical carcinomas are causally linked to infections with high-risk human papillomaviruses (HPVs), whose oncogenicity has been assigned to the continued expression of two early genes, E6 and E7. Reversal of the transformed phenotype by inhibiting E6/E7 gene expression therefore provides a suitable goal for future tumor therapy. Using recombinant adeno-associated virus type 2 (AAV-2) vectors, two types of therapeutic genes were expressed in cervical carcinoma cells with the aim of suppressing the E6/E7 oncogenes: (a) antisense E6/E7 and ribozyme genes and (b) the monocyte chemoattractant protein-1 (MCP-1) gene encoding MCP-1. Previous studies have shown that the MCP-1 protein is able to indirectly repress E6/E7 gene expression and is consistently absent in tumorigenic HPV-positive cervical carcinoma cell lines. Here, the effect of these therapeutic genes on tumor formation is analyzed in nude mice after ex vivo gene transfer into a HPV16- or HPV18-positive cervical carcinoma cell line (HeLa or SiHa, respectively). Whereas AAV-2 vector-mediated transfer of antisense or even ribozyme genes did not significantly influence tumor formation from implanted SiHa cells, the transfer and expression of human MCP-1 strongly inhibited the development of tumors derived from either HeLa or SiHa cells. Similar results were also obtained after in vivo delivery of these genes into SiHa-derived tumors. This suggests that transfer of therapeutic genes mediating a systemic effect via recombinant AAV-2 vectors offers a promising approach for the development of gene therapies directed against papillomavirus-induced human cancers.     

Quantitative features of chromatin structure in the prognosis of breast cancer.

In prognosis of breast cancer different parameters are in current use. Along with clinical staging the most important parameter appears to be histologic grading. Features of the grading such as nuclear pleomorphism proved to correlate closely with the proliferative activity and aggressiveness of the tumors. Because of difficulties in assessing and classifying the degree of nuclear pleomorphism by usual microscopy, the authors applied methods of digital image analysis. The study is a retrospective analysis of paraffine slides from the primary lesions of 60 breast cancers with 10 to 16 years of follow-up evaluation. Using large sets of different parameters defining nuclear morphology and chromatin structure the authors extracted criteria with prognostic importance. These included nuclear area in micron 2, eccentricity, integral optical density per micron 2, average area of a chromatin region, integral optical density of a chromatin region per micron 2, and the number of central chromatin regions per micron 2. The results demonstrate that the criteria used enable prediction of prognosis with an accuracy of 92%.     

Various shor-term assays and two long-term studies with the plasticizer di(2-ethylhexyl)phthalate in the Syrian golden hamster

The plasticizer di(2-ethylhexyl)phthalate (DEHP) and its mainmetabolite monoethylhexylphthalate (MEHP) were investigatedin several short-term in vitro assays, including mutagenicityin Salmonella typhimurium TA102, a strain sensitive to mutationsarising as a cause of oxidative DNA damage. Also DNA amplificationin SV40-transformed Chinese hamster cells and DNA damage inrat and hamster hepatocytes were investigated. The two compoundswere not genotoxic in any of the test systems. Furthermore,DEHP was investigated in two long-term bioassays with Syriangolden hamsters using both i.p. (max. total dose 54 g/kg) andinhalative (7–10 mg/kg) application. In both experimentsan additional group of animals received a combination treatmentof DEHP with N-nitrosodimethylamine (NDMA). These studies wereincluded in order to elucidate whether the observed influenceof DEHP on the microsomal enzyme activity (Seth, 1982) may effectthe carcinogenic activity of NDMA. There was no significantincrease in tumor incidence after application of only DEHP viaboth routes. However, the occurrence of liver malignancies wassignificantly (P<0.001) reduced after the combination treatmentin the inhalation study.     

Characterization of BSp73, a spontaneous rat tumor and its in vivo selected variants showing different metastasizing capacities

BSp73 arose spontaneously (1979) as intraperitoneal nodules together with ascites. Histologically, the nodules were classified as adenocarcinoma of the pancreas. During serial transplantation of ascites cells to a subcutaneous site, two variants appeared--one fast-growing, nonmetastasizing, the other slowly growing and metastasizing via the lymphatic system to the lung. From the in vivo selected variants as well as from the parental tumor, two types of tissue cultured cell lines were established. These differed in morphology, adherence to plastic, susceptibility to detachment by trypsin, and, above all, in the ability to metastasize upon reinjection into syngeneic recipients. From differences in growth kinetics in vivo it has to be concluded that variant cell types coexisted in the parental tumor in the form of precursors, which adopted their characteristic features (irreversibly) after a shift in the environment.