Human Wilms Research Articles

Insulin stimulation of glucose transport and metabolism in a human Wilms' tumor-derived myoblast-like cell line: modulation of hormone effects by glucose deprivation.

The effects of insulin and glucose on parameters of metabolism were investigated in myoblast-like (MBL) cells, a human myoblast-like cell line derived from a Wilms' tumor. Insulin responses were studied after 4 hr pre-incubation in serum free media, with or without 5 mM glucose. Insulin was added during the last 2 hr. Glucose starvation markedly increased basal glucose transport (measured as 2-deoxyglucose uptake) as well as the net uptake of [14C]glucose and [14C]glucose incorporation into glycogen. Insulin stimulated net glucose uptake and incorporation into glycogen in a dose-dependent manner in glucose-fed and starved cells. These insulin responses were markedly enhanced in glucose-starved cells. Insulin accelerated 2-deoxyglucose transport in glucose-fed cells but did not further stimulate basal glucose transport in glucose-deprived cells. Insulin increased the incorporation of [3H]leucine into protein in glucose-fed or -starved MBL cells equally. The dose of insulin required for half-maximal insulin responses was similar for all parameters studied. Cycloheximide did not prevent the increased basal glucose incorporation in glucose-starved cells, but markedly inhibited the insulin response, while in glucose-fed cells, cycloheximide stimulated basal glucose incorporation. We conclude that MBL cells resemble fibroblasts in their insulin-independent stimulation of glucose transport in response to glucose-deprivation; when provided with glucose, they respond to insulin like fibroblasts. However, after brief glucose-starvation, the stimulated glucose transport system is no longer insulin-responsive in MBL cells, while pathways leading to the synthesis of macromolecules demonstrate preserved or enhanced stimulation by insulin, suggesting that these cells may serve as models to study the regulation of receptor-response coupling by the metabolic milieu.

Quantitation of angiogenesis factor in bovine retina and tumour extracts by means of radioimmunoassay.

Using an antiserum raised against tumour angiogenesis factor (TAF) we have developed a radioimmunoassay for retina and tumour angiogenesis factor(s). This antiserum was previously shown to bind to both human and animal tumour extracts and to inhibit the angiogenesis induced by TAF in vivo. TAF from rat Walker tumour was used for iodination by the chloramine-T method. An excess of 125I-labelled TAF was incubated with TAF antibody in the absence (maximum binding) and presence (inhibition of maximum binding) of unlabelled tissue extract. A double antibody technique was used to separate free and bound TAF. Unlabelled human Wilms tumour TAF was used as a standard. The extent of inhibition of 125I-TAF-anti-TAF binding provided a measure of TAF in tissue extracts examined. Extracts of normal bovine retina, cornea, lung, aorta, lymph nodes, iris, vitreous humour, and human tumours and normal human pituitary and liver were assayed. Only bovine retina and human tumours were found to contain angiogenesis factor. These findings, together with our earlier results, suggest that angiogenesis factor from both bovine retina and human tumours induce angiogenesis in vivo and possess common antigenic determinants. The presence of angiogenesis factor in healthy retina and its relationship to neovascularisation in clinical conditions is discussed.

Effect of postoperative chemotherapy and radiotherapy, on the survival of subcutaneously implanted Furth Wilms' tumor.

The effect of surgery, postoperative combination chemotherapy and postoperative radiotherapy was evaluated in subcutaneously implanted Wistar/Furth rat Wilms' tumor. Four groups were studied. Group A (controls, no treatment given) had a median survival of 44 days. Group B (surgical excision of the primary tumor on day 14 after implantation) showed a median survival of 77 days, with 40% tumor-free long-term survivors (sacrificed on day 175). Group C (excision followed by chemotherapy consisting of vincristine, actinomycin D and adriamycin) had a median survival of 61 days with 35% tumor-free long-term survivors. Group D received the same postoperative chemotherapy as well as radiotherapy and had 55% tumor-free long-term survivors. This tumor may serve as a treatment model for some human Wilms' tumor cases who do not respond well to current therapies.

L-Azaserine toxicity in established cell lines : Correlation with γ-glutamyl transpeptidase activity

Four established cell lines derived from pig kidney (LLC-PK 1), human Wilms' tumor (TuWi), rat liver (ARL 6), and hamster lung (V79) were found to contain widely divergent levels of γ-glutamyl transpeptidase (GGT) which decreased in the order given from 96 nmole p-nitroaniline released/min/mg protein for LLC-PK 1 to 0.5 nmole for V79, independent of cell density. When lines were treated with l-azaserine for short periods, a positive correlation was observed between cellular GGT levels and sensitivity to azaserine toxicity. Equimolar concentrations of l-serine and l-glutamine were non-toxic. Azaserine-resistant strains were isolated from TuWi cultures exposed to l-azaserine for 24 h. Most exhibited reduced levels of GGT. Those strains expressing the lowest GGT activities also showed the greatest resistance to azaserine toxicity following short-term re-exposure to l-azaserine. These results indicate that GGT is an important determinant in cell sensitivity to l-azaserine toxicity and suggest that heightened susceptibility is a consequence of active transport of the diazo-amino acid.

Nephroblastoma in the Rat: Histology of a Spontaneous Tumor, Identity With Respect to Renal Mesenchymal Neoplasms, and a Review of Previously Recorded Cases2

The histology of a spontaneously occurring neoplasm of the rat kidney conforming to a classification of nephroblastoma is described and compared with that of N-nitrosodimethylamine-induced renal mesenchymal tumors. This rat nephroblastoma was an encapsulated epitheloid neoplasm with a uniform histologic pattern. Clumps of densely crowded, hyperchromatic cells frequently associated with central, well-differentiated ducts were supported by a less cellular, interconnecting stroma of loose areolar or mature fibrous connective tissue. Neoplastic cells were organized into primitive, ill-defined tubular formations. The neoplastic cell component strongly resembled metanephrogenic blastema. In contrast, the renal mesenchymal tumor was nonencapsulated and consisted of a heterogeneous mixture of connective tissue elements including fibroblast-like spindle cells, smooth muscle, and embryonic mesenchyme that engulfed and sequestered preexisting renal tubules and glomeruli. The separate morphologic identities and apparently unrelated existence of rat nephroblastoma and renal mesenchymal tumor were stressed. The rat nephroblastoma morphologically resembled the malignant epithelial component of human Wilms' tumor, whereas rat renal mesenchymal tumor appeared to have counter-parts in the mesenchymal component of Wilms' tumor and in congenital mesoblastic nephroma (leiomyomatous hamartoma) of infancy. The histologic descriptions of previously recorded occurrences of spontaneous and experimentally induced rat neoplasma classified as nephroblastoma or its synonyms were reevaluated in comparison to the present case. In all but four instances, in which sufficient histologic detail was provided in previous reports, a consistent histologic pattern emerged for this neoplasm in the rat.

A Murine Wilms' Tumor as a Model for Chemotherapy and Radiotherapy 2 3

We studied the effect on tumor volumes and host survival of twenty-four chemotherapeutic and radiotherapeutic regimens in rats bearing the Furth/Columbia murine Wilms' tumor. After 5 years and some 100 transfers, this tumor retained its sensitivity to suitable combinations of actinomycin D, vincristine, and X-ray, regimens in current use in the treatment of human Wilms' tumor. Cytoxan alone was highly inhibitory; adriamycin was modestly inhibitory; and lethal doses of methotrexate followed by leucovorin "rescue" were slightly inhibitory to the growth of the rat tumor. No other chemotherapeutic agent tested was effective by our criteria. Cytoxan, with or without adriamycin, and X-irradiation, were the most useful combinations studied. The chemotherapeutic agents given 3 days before irradiation were significantly more carcinostatic than they were when given after radiotherapy.

Detection of a small virus in a cultivated human Wilms' tumor.

After 15 months of in vitro cultivation and after “spontaneous transformation” from a fibroblastoid to epithelioid morphological appearance, a human Wilms' tumor culture was shown by electron microscopy to contain a small virus. The virus measures 45-50 mμ in diameter, contains an electron-dense nucleoid, and is surrounded by a closely adherent double-membrane. Thus, morphologically, it resembles papova viruses. Attempts to establish in vitro and in vivo activity of the virus, thus far, have been unsuccessful. Viral replication has been demonstrated only by electron microscopy in the cultivated cells where virus was first detected. Attempts are continuing to establish a biological assay for the virus and to recover similar agents from other Wilms' tumors.

Ultrastructural studies in Wilms's tumor.

Light and electron-microscopic features based on tissues from three human Wilms's tumors (nephroblastomas) are described and their significance discussed with respect to the histogenesis of the tumors. Tumor cells exhibited various levels of differentiation including well-formed tubules with fine structural characteristics of normal proximal tubules, and glomeruloid structures composed of epithelial cells with cytoplasmic processes suggesting the podocytes and foot processes of the glomerulus, but lacking blood cells, capillaries or mesangial cells. The glomeruloid structures contained what appeared to represent aberrant basement membrane formation corresponding to the PAS positive material observed with the light microscope. Electron microscopy revealed more definitive epithelial features than possible with the light microscope. These ultrastructural observations suggested an origin of Wilms's tumor in the metanephrogenic blastema.