Whole-body subcellular multicolor imaging of tumor-host interaction and drug response in real time

To noninvasively image cancer cell/stromal cell interaction in the tumor microenvironment and drug response at the cellular level in live animals in real time, we developed a new imageable three-color animal model. The model consists of green fluorescent protein (GFP)-expressing mice transplanted with dual-color cancer cells labeled with GFP in the nucleus and red fluorescent protein in the cytoplasm. The Olympus IV100 Laser Scanning Microscope, with ultra-narrow microscope objectives ("stick objectives"), is used for three-color whole-body imaging of the two-color cancer cells interacting with the GFP-expressing stromal cells. In this model, drug response of both cancer and stromal cells in the intact live animal is also imaged in real time. Various in vivo phenomena of tumor-host interaction and cellular dynamics were imaged, including mitotic and apoptotic tumor cells, stromal cells interacting with the tumor cells, tumor vasculature, and tumor blood flow. This new model system enables the first cellular and subcellular images of unperturbed tumors in the live intact animal. New visible real-time targets for novel anticancer agents are provided in this model, including the color-coded interacting cancer and stromal cells, tumor vasculature, and blood flow. This imageable model should lead to many new insights of in vivo cancer cell biology and to novel drug discovery.     

Hereditary alterations in tumor-host relationship

An indirect exposure of mice during their fetal stage of development to Ehrlich ascites tumor cells alters the animals' response to this tumor during their adult life. Control mice injected intraperitoneally with Ehrlich tumor cells react in various ways to the presence of this alien tissue. The response is expecially evident during the first 48–72 h post-injection. Several aspects of this complex reaction are absent in those animals which were exposed to this tumor in utero. The measurably altered reactivity toward the Ehrlich tumor cells is hereditary. Possible mechanisms of this alteration are discussed.     

Suppression of wound healing in tumor bearing animals as a model for tumor-host interaction: mechanism of suppression

Tumor wound healing was explored as a possible model for tumor-host interactions. Wound healing within tumors progressed normally through the hemorrhagic and inflammatory stages but failed at the mesenchymal ingrowth phase. Due to this failure of mesenchymal ingrowth, no significant collagen deposition could be detected within tumor wounds. Fluid collected from tumor wounds markedly altered fibroblast cytoskeletal structures and profoundly inhibited fibroblast proliferation and collagen synthesis. This suppression did not appear to be the direct consequence of tumor products, since tumor conditioned media enhanced fibroblast proliferation and had no effects on collagen synthesis and fibroblast cytoskeleton. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of lysed fibroblasts demonstrated that two polypeptides (Mr 280,000 and 240,000) were induced in or adherent to fibroblasts exposed to fluid from the tumor wound but not in fibroblasts exposed to fluid obtained from wounds in normal tissue or tumor conditioned media. These findings suggest that tumor wound healing is a model for mesenchymal inhibition within tumors but that the inhibitors are not tumor derived products.     

Prognostic significance of tumor-host interaction in clinical gastric cancer: Relationship between dna ploidy and dendritic cell infiltration

DNA ploidy of tumor cells and the degree of infiltration of dendritic cells were determined in 93 gastric cancer tissue specimens, and the mechanisms of tumor-host interaction on the prognosis were investigated. DNA ploidy patterns were grouped into low and high ploidy, and the degree of infiltration of dendritic cells (DC) was graded into marked and slight infiltration. In the low ploidy group, the 5-year survival rates in patients with marked and slight DC infiltration were 80.7% and 61.5%, respectively (P < 0.05). In the high ploidy group, however, there were no significant differences. In cases of low ploidy, the incidence of lymph node metastasis was significantly lower in the marked DC infiltration group compared with findings in the slight DC group. Thus, markedly infiltrating dendritic cells in gastric cancer tissue may lead to prolongation of survival time for patients with a carcinoma of the low ploidy profile, by preventing widespread nodal involvement. © 1993 Wiley-Liss, Inc.     

Spatially resolved multi-omics deciphers bidirectional tumor-host interdependence in glioblastoma

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Interleukin-1--a major pleiotropic cytokine in tumor-host interactions

Interleukin-1 (IL-1) represents a family of two agonistic proteins, IL-1alpha and IL-1beta, that are pleiotropic and affect hemopoiesis, inflammation, and immunity. In the context of the producing cell, IL-1beta is solely active in its secreted form, whereas IL-1alpha is active as an intracellular precursor, as a membrane-associated cytokine and to a lesser extent as a secreted molecule. IL-1 is abundant at tumor sites, where it may not only affect the growth and invasiveness of malignant cells, but where it may also induce antitumor immunity. Here we review the effects of microenvironmental and tumor cell-associated IL-1 on malignant processes, in experimental tumor models and in cancer patients.     

Cancer metastasis: A product of tumor-host interactions

Metastasis continues to be the most devastating event for the patient with an established primary cancer. The most significant therapeutic problems are: (1) treatment of patients with established macrometastases, (2) identification of patients who have micrometastases and (3) the development of adequate adjunctive therapies for micrometastases. It is hoped that our evolving understanding of the biology of experimental metastasis and the high level of premium quality laboratory research ongoing in this area will result in further resolution of this clinical problem or, at least, a better understanding of this most extreme expression of the malignant phenotype.     

Fibroblast enhancement of tumor invasion in a tumor-host interface recapitulated in-vitro

Tumor cells and fibroblasts were isolated from the tumor-host interface of a colon 4047 tumor growing subcutaneously in a Fischer 344 rat. The populations were co-cultured to recapitulate the tumor-host interface in vitro. The co-cultured populations grew in a predictable pattern with tumor cells forming nodules surrounded by fibroblasts. Population dynamic experiments demonstrated the fibroblasts enhanced the growth of the tumor cells but tumor inhibited and ultimately destroyed the fibroblasts. Video microscopic examination of the fibroblasts demonstrated intense membrane ruffling adjacent to the tumor nodules followed by membrane fragmentation and detachment. Immunohistochemical staining for gelatinase A was markedly positive within the fibroblasts surrounding the tumor nodules; but negative within the tumor and in fibroblasts when tumor was absent. This technique recapitulates many aspects of the tumor-host interface in vitro and may be a useful model for evaluating several aspects of tumor-host interaction.     

Total parenteral nutrition and inhibition of gluconeogenesis on tumor-host responses.

Rats bearing the Morris hepatoma No. 7777 were randomized into three treatment groups. Two of the groups received a nutritionally complete liquid formula diet per os ad libitum. One of these two groups received hydrazine sulfate (HS; an inhibitor of gluconeogenesis) twice daily (15 mg/kg) for 5 days. A third group of tumorous rats received the HS therapy and was given the liquid diet parenterally for 5 days. Tumorous rats fed per os, especially with HS therapy demonstrated inhibition of tumor growth, reduction of body and carcass weight, anorexia and decreased nitrogen retention. The combination of parenteral feeding and HS therapy sustained body and carcass weight with high nitrogen retention but stimulated tumor growth and was associated with liver toxicity. These results support the concept that cancer cachexia involves 'a systemic energy-losing cycle dependent on an interplay of tumor glycolysis and gluconeogenesis'.     

Hormone receptor levels related to histological parameters of tumor-host relationships in female breast carcinoma

A series of 115 female breast carcinomas was studied with special emphasis on the relationships between the hormone receptor (ER and PR) levels and the histological parameters reflecting tumor-host reactivity. Carcinomas were classified according to their nuclear grade (NC) and the stromal host reactions; perivenous lymphocyte infiltration (PVI), lymphocyte (LD), plasma cell (PCI), and mast cell infiltration (MI) were assessed. NG did correlate directly with the ER positivity, but not with the absolute ER values. LI and PCI, but not MI and PVI, showed an inverse relation to the ER values, but not to those of PR. ER and to lesser extent the PR values were higher in postmenopausal than in premenopausal women. The findings are discussed in the light of tumor-host relationships, and conclusion is drawn that the receptor determinations used in connection with the histological evaluation of these parameters (NG especially) are of definite benefit in dividing the breast cancer patients into groups of different expectancy of the future outcome of their disease.     

Loss of smooth muscle calponin results in impaired blood vessel maturation in the tumor-host microenvironment

The interactions between malignant cells and the microenvironment of the local host tissue play a critical role in tumor growth, metastasis and their response to treatment modalities. We investigated the roles of smooth muscle calponin (Cnn1, also called calponin h1 or basic calponin) in the development of tumor vascul ature in vivo by analyzing mutant mice lacking the Cnn1 gene. Here we show that loss of Cnn1 in host mural cells prevents maturation of tumor vasculature. In vitro studies showed that platelet-derived growth factor B-induced vascular smooth muscle migration was downregulated by the Cnn1-deficiency, and forced expression of Cnn1 restored migration. Moreover, destruction of established tumor mass by treatment with an antivascular endothelial growth factor antibody was markedly enhanced in Cnn1-deficient mice. These data, coupled with the knowledge that structural fragility of normal blood vessels is caused by loss of the Cnn1 gene, suggest that Cnn1 plays an important role in the maturation of blood vessels, and may have implications for therapeutic strategies targeting tumor vasculature for treatment of human cancers.     

The involvement of IL-1 in tumorigenesis, tumor invasiveness, metastasis and tumor-host interactions

Interleukin-1 (IL-1) includes a family of closely related genes; the two major agonistic proteins, IL-1α and IL-1β, are pleiotropic and affect mainly inflammation, immunity and hemopoiesis. The IL-1Ra antagonist is a physiological inhibitor of pre-formed IL-1. Recombinant IL-1α and IL-1β bind to the same receptors and induce the same biological functions. As such, the IL-1 molecules have been considered identical in normal homeostasis and in disease. However, the IL-1 molecules differ in their compartmentalization within the producing cell or the microenvironment. Thus, IL-1β is solely active in its secreted form, whereas IL-1α is mainly active in cell-associated forms (intracellular precursor and membrane-bound IL-1α) and only rarely as a secreted cytokine, as it is secreted only in a limited manner. IL-1 is abundant at tumor sites, where it may affect the process of carcinogenesis, tumor growth and invasiveness and also the patterns of tumor–host interactions. Here, we review the effects of microenvironment- and tumor cell-derived IL-1 on malignant processes in experimental tumor models and in cancer patients. We propose that membrane-associated IL-1α expressed on malignant cells stimulates anti-tumor immunity, while secretable IL-1β, derived from the microenvironment or the malignant cells, activates inflammation that promotes invasiveness and also induces tumor-mediated suppression. Inhibition of the function of IL-1 by the IL-1Ra, reduces tumor invasiveness and alleviates tumor-mediated suppression, pointing to its feasibility in cancer therapy. Differential manipulation of IL-1α and IL-1β in malignant cells or in the tumor’s microenvironment can open new avenues for using IL-1 in cancer therapy.     

Low molecular weight inhibitors of Myc-Max interaction and function

c-Myc is helix-loop-helix-leucine zipper (HLH-ZIP) oncoprotein that is frequently deregulated in human cancers. In order to bind DNA, regulate target gene expression, and function in a biological context, c-Myc must dimerize with another HLH-ZIP protein, Max. A large number of c-Myc target genes have been identified, and many of the encoded proteins are transforming. Such functional redundancy, however, complicates therapeutic strategies aimed at inhibiting any single target gene product. Given this consideration, we have instead attempted to identify ways by which c-Myc itself could be effectively disabled. We have used a yeast two-hybrid approach to identify low-molecular-weight compounds that inhibit c-Myc-Max association. All of the compounds prevented transactivation by c-Myc-Max heterodimers, inhibited cell cycle progression, and prevented the in vitro growth of fibroblasts in a c-Myc-dependent manner. Several of the compounds also inhibited tumor growth in vivo. These results show that the yeast two-hybrid screen is useful for identifying compounds that can be exploited in mammalian cells. More specifically, they provide a means by which structural analogs, based upon these first-generation Myc-Max inhibitors, can be developed to enhance antitumor efficacy.