Calorie restriction: effect on growth of human tumors heterotransplanted in nude mice

The presence of 4 human malignant tumors (1 breast, 1 lung, and 2 colon carcinomas) growing subcutaneously as heterotransplants in nude mice did not significantly affect the body weights of adult animals until the tumors reached very large dimensions (tumor wt greater than 15% of the body wt). However, a colon carcinoma (HT 29) induced a cessation of the natural rate of body weight increase when it grew in young adults (animals weighing approximately equal to 25 g which will gain 6 g or approximately equal to 25% body wt in 1 mo). Calorie restriction at all the levels tested (8, 6, 4, and 2 g/day/mouse) with standard pelletized mouse food produced both weight loss in the animals (with and without tumor) and a lowering of the growth rate of all the 4 tumors tested growing at a subcutaneous site and/or under the kidney capsule. Each tumor responded differently to the calorie restriction. The 4 tumors tested grew equally in both male and female nude mice. Young animals weighing 20 g inoculated with a fifth tumor (MeWo melanoma) exhibited tumor growth inhibition proportional to restriction of calorie intake. Their survival, however, did not improve.     

Chromosomes and causation of human cancer and leukemia. XXX. Banding studies of primary intestinal tumors

The chromosomes of 15 primary intestinal tumors were analyzed with a banding technique. Of the 15 tumors, 12 had some chromosomal abnormalities (8 with numerical changes and 4 with both numerical and structural abnormalities) and in the remaining three no karyotypic abnormalities were found. No common marker chromosomes were seen among the various tumors and no two tumors with chromosomal changes and identical karyotypes, though some chromosomes were involved more often than others. Excessive chromosomes in the primary tumors were usually due to extra chromosomes in the following groups (numbers of tumors involved are shown in parenthesis): No. 8 (7), No. 13 (4), No. 15 (4), No. 17 (6) and No. 21 (6). On the other hand, chromosomes losses, though much less frequent, involved chromosomes No. 5, No. 6, No. 7, No. 10 and No. 16. Most of the tumor cells with chromosomal changes were hyperdiploid and usually contained less than 60 chromosomes. Only one tumor contained hypodiploid cells. The cytogenetic data presented on primary intestinal tumors indicate that they consist primarily of numerical changes, relative infrequency (when compared to metastases) and small number (1-4) of markers.     

Response and determinants of sensitivity to paclitaxel in human non-small cell lung cancer tumors heterotransplanted in nude mice.

The lack of tumor models that can reliably predict for response to anticancer agents remains a major deficiency in the field of experimental cancer therapy. Although heterotransplants of certain human solid tumors can be successfully grown in nude mice, they have never been appropriately explored for prediction of in vivo chemosensitivity to anticancer agents. We determined the tumor response rate and studied the influence of several biological and molecular tumor parameters on the in vivo sensitivity to paclitaxel in a series of heterotransplanted human non-small cell lung cancer (NSCLC) tumors. One hundred consecutive resected NSCLC tumors were heterotransplanted s.c. in nude mice. The in vivo sensitivity to i.v. paclitaxel (60 mg/kg every 3 weeks) was studied in 34 successfully grown heterotransplants. Treatment started when the tumors reached a size of 5 mm in diameter, and strict standard clinical criteria (>50% shrinkage in tumor weight or cross-sectional surface) were used to define tumor response. Baseline multidrug resistance protein (MRP), Her-2/neu, and epidermal growth factor receptor (EGFR) expression, and pre- and posttherapy bax and bcl-2 expression were determined by Western blot analysis. p53 status was determined by sequencing. The overall take rate was 46% (95% confidence interval, 36-56%) and was significantly higher (P < 0.05) for squamous carcinoma tumors (75%) than for adenocarcinoma tumors (30%) and bronchoalveolar tumors (23%). The heterotransplants were morphologically very similar to the original tumors. The response rate to paclitaxel was 21% (95% confidence interval, 9-38%). Baseline tumor parameters associated with response were no Her-2/neu expression (none of the responding tumors expressed Her-2/neu versus 48% of the nonresponding tumors, P = 0.05) and baseline bcl-2 expression (all responding tumors expressed bcl-2 versus only 43% of the nonresponding tumors, P = 0.02). There was a trend toward a higher response rate in bax-positive tumors, and MRP- and EGFR-negative tumors, but it was not statistically significant. The response was independent of baseline p53 status and baseline mitotic index. Responding tumors had a higher bax/bcl-2 ratio 24 h after therapy, but the difference was only marginally significant (2.8 for responding tumors versus 1.1 for nonresponding tumors, P = 0.07). The extent of mitotic arrest at 24 h after therapy was not associated with response. Human NSCLC heterotransplants are morphologically identical to the original tumors and have a response rate to paclitaxel that is equivalent to that reported in Phase II studies in patients with advanced NSCLC treated with single-agent paclitaxel. NSCLC heterotransplants deserve to be explored to evaluate new agents for lung cancer and to predict clinical response on an individual basis in selected groups of patients.     

Elevated adenosine 3',5'-cyclic monophosphate levels in human and animal tumors in vivo.

Cyclic AMP (cAMP) levels were measured in several animal and human tumors and in normal human tissues. Malignant tissues did not appear to be deficient in cAMP.     

Antitumor activity of murine tumor necrosis factor (TNF) against transplanted murine tumors and heterotransplanted human tumors in nude mice

The antitumor activity of highly purified tumor necrosis factor (TNF) was tested against eight kinds of murine tumor and five kinds of human tumor heterotransplanted into nude mice. Mice were treated by intravenous or intratumoral injection of TNF, commencing when the tumors were well established. TNF showed an excellent curative effect against all kinds of murine and human tumors tested. Meth A sarcoma, Colon 26, Ehrlich, sarcoma 180, MM 46, MH 134, B16 melanoma, and Lewis lung tumors transplanted into mice underwent tumor necrosis and regression following a single injection of TNF. Sometimes a complete cure was observed in Meth A sarcoma, sarcoma 180, Ehrlich, and MM 46 tumors. Human cancers, SEKI, HMV-I, KATO-III, MKN 45, or KB, heterotransplanted into nude mice, also exhibited tumor necrosis and regression in size following several intratumoral injections of TNF. A great difference in curative effects of TNF was observed in Meth A sarcomas between those transplanted into BALB/c nu/+ and into BALB/c nu/nu mice: following a single intravenous administration the effect was stronger in BALB/c nu/+ than in nu/nu mice. In contrast, tumor necrosis was almost the same in nu/+ and nu/nu mice following intratumoral administration. The present results thus indicate that TNF from mice had an antitumor activity against not only murine tumors but also human tumors. In addition to direct cytotoxicity against tumor cells, TNF induced a host-mediated factor which contributed to the antitumor effects.     

Antitumor activity of recombinant human interleukin-1 against heterotransplanted human non-Hodgkin lymphomas in nude mice

Antitumor activity of recombinant human interleukin 1 alpha (IL-1) against seven human non-Hodgkin lymphomas grown in athymic nude mice was studied. Growth of the lymphomas was markedly inhibited after an injection of 0.4 mg/kg IL-1. The growth inhibition of Burkitt lymphoma was found to be dose-dependent up to 0.4 mg/kg, reaching a plateau thereafter. The loss of colony-forming ability of the cells and the loss of cell viability showed the same type of dose-dependence and progressed during 24 h following an injection of IL-1. In accordance with these observations, histopathologic examination revealed progressively spreading coagulative necrosis without bleeding. Little infiltration of inflammatory cells into the tumor tissue was observed. IL-1 growth inhibition of T lymphoma in beige nude mice having low natural killer activity was similar to that in nude mice. These findings suggested that the antitumor effects might not be produced through cell-mediated antitumor actions. Immunocytological examination with anti-IL-1 antibody revealed that administered IL-1 was bound to the lymphoma cells, suggesting that IL-1 receptor is probably expressed on these cells in vivo. The antitumor action of IL-1 on the lymphomas may be exerted directly through the IL-1 receptor.     

Somatostatin receptor subtypes sst1, sst2, sst3 and sst5expression in human pituitary,gastroentero-pancreatic and mammary tumors

Using in situhybridization techniques with selective oligoprobes, the gene expression of sst₁, sst₂, sst₃ and sst₅ was studied in a series of 32 human pituitary adenomas, 28 breast tumors and 21 endocrine gastroentero-pancreatic tumors, shown to express somatostatin receptors to variable extents. In most of these tumors the sst₂ receptor subtype was abundantly expressed, even though a significant number of pituitary adenomas, breast and gastroentero-pancreatic tumors expressed sst₁ and/or sst₃ as well. A very high incidence of the sst₅subtype was found in growth hormone-producing pituitary adenomas and, to a lesser extent, in inactive pituitary adenomas, whereas breast tumors seldom expressed sst₅; gastroentero-pancreatic tumors showed all possible combinations of sst expression, with, however, a predominance of sst₂ and sst₁. Overall, the presence of sst₂ mRNA and/or sst₅ mRNA generally correlated with the presence of octreotide binding sites. A lack of octreotide binding sites corresponded with a lack of sst₂ mRNA. Several tumors exhibiting a low number of octreotide binding sites had no measurable sst₂ mRNA, despite abundance of β-actin mRNA, suggesting in these cases a very low abundance of sst mRNAs or a too low sensitivity of the in situ hybridization methodology. In all other cases, the method allowed precise localization of the respective mRNAs on the tumor tissue, notably in breast tumors with non-homogeneous receptor distribution. Tumors without measurable amounts of somatostatin receptors had no detectable sst mRNA. Our results indicate a highly variable abundance of the various sst mRNAs in individual somatostatin receptor-containing tumors. Int. J. Cancer 70:530–537. © 1997 Wiley-Liss Inc.     

Determinants of 5-fluorouracil sensitivity in human tumors.

It is not apparent that advanced human carcinomas of the breast or the large bowel are conprised of at least two populations: those responding to treatment with 5-fluorouracil (approximately 20 per cent) and those unresponsive to this drug. This classification cannot be made before chemotherapy on the basis of any clinical parameter. Biochemical parameters to distinguish between responding and nonresponding tumors are being sought in this laboratory. Techniques have been developed to measure thymidylate synthetase, the target enzyme for 5-fluorouracil, 5-fluoro-2'-deoxyuridylate, the active form of the antimetabolite, and 2'-deoxyuridylate, the naturally occuring competing metabolite. These methods are sufficiently sensitive to permit analysis of these parameters in needle biopsy specimens, and do not require exposure of patients to radioisotopes.