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F R Miller

Publications and source records attributed to F R Miller.

At least 73 records · Page 4Linked to original sources
PubMed1989

Therapeutic perturbation of the tumor ecosystem in reconstructed heterogeneous mouse mammary tumors.

We have measured the response to methotrexate in vivo of paired mixtures of sister subpopulation lines from a mouse mammary tumor, as a model of drug response of a heterogeneous tumor. The subpopulation lines differed in intrinsic sensitivity to methotrexate. Response was measured both as growth delay and as a shift in tumor cell population distribution toward the more resistant cell line. We found differences between two pairs of cell lines in growth delay: line 66 plus 4T07 mixtures tended to be as responsive as was line 4T07 (the more sensitive line) alone, whereas line 168 plus 4T07 mixtures tended to be less responsive than line 4T07 alone. With both paired mixtures, the tumors arising after treatment tended to contain more line 66 or line 168 than did untreated tumors, but this shift was extremely variable among individual tumors. Within most treatment groups, there was no correlation between the growth rate of individual mixed tumors and the final tumor cell distribution. Likewise, between experiments, there was no correlation between the amount of growth delay in mixed tumors and the final tumor cell distribution. Thus, the cellular composition of treated tumors did not directly reflect the response to therapy.

Animals↗
PubMed1988

Expression of epithelial-like markers and class I major histocompatibility antigens by a murine carcinoma growing in the mammary gland and in metastases: orthotopic site effects.

A spontaneous murine mammary carcinoma, designated SP1, grew more aggressively in the mammary gland than in the subcutis exhibiting a 10-fold lower 50% lethal tumor dose and the ability to metastasize spontaneously from the orthotopic mammary gland site. The appearance of metastasis could be abrogated by resection of the primary tumor up to 21 days postinjection, arguing against the possibility that metastasis occurred due to trauma of the injection and/or healing processes. In addition, tumor cells recovered from lung metastases exhibited an increased ability to metastasize when reinjected into either the s.c. or mammary sites. Tumor cells from lung metastases showed low levels of Class I major histocompatibility (MHC) antigens, like the parental SP1 cells, but were found to express differentiation markers typical of normal basal and luminal mammary epithelium. SP1 tumors expressed increased Class I MHC antigens, as well as high levels of basal and luminal breast epithelial markers, within 7 days of implantation into the mammary gland. On the other hand, SP1 tumors growing in the subcutis never expressed increased Class I MHC levels and expressed the epithelial marker antigens at lower levels and not until at least 21 days of growth. Removal of host epithelium by cauterization of the mammary bud at 3 weeks had no effect on the increased growth, metastasis and acquired heterogeneity of MHC and epithelial associated antigens, suggesting that the mammary gland stroma was responsible for the observed phenomenon. These findings suggest that the mammary gland either selects distinct tumor subpopulations, or induces a phenotypic change leading to tumor progression and the generation of metastatic subpopulations.

Animals↗
PubMed1988

Dominance of a tumor subpopulation line in mixed heterogeneous mouse mammary tumors.

When mixtures of cell lines 168 and 4T07, both derived from the same mouse mammary tumor, were injected into syngeneic mice, the resulting tumors, analyzed over a large size range by colony-forming assays in selective media, consisted primarily of line 4T07, even when the ratio injected was 100:1 or greater in favor of line 168. This result indicated a suppression of growth of line 168, since the volume-doubling time of line 168 tumors in the absence of line 4T07 was one-half that of line 4T07 tumors. That growth suppression was not due to inhibition of line 168 by immunity induced to line 4T07 was shown in two ways: (a) line 168 tumors grew almost as well in mice preimmunized with line 4T07 as in controls, whereas line 4T07 tumor growth was strongly inhibited in preimmunized mice; and (b) the final composition (favoring line 4T07) in mixed tumors was similar in tumors grown in mice immunosuppressed by irradiation to that in nonirradiated controls. The strong suppression of line 168 did not occur when the two cell lines were injected simultaneously at different s.c. sites, nor did it occur when line 168 cells were injected in mixtures with lethally irradiated line 4T07 cells. Line 4T07 cells also suppressed the growth of line 168 cells in monolayer cultures. It was not likely that suppression was due to competition for growth factors, since the effect required cell contact. Suppression probably was not mediated through junctional communication, since these cells do not engage in metabolic cooperation. We suggest that a growth-inhibitory factor produced by line 4T07 mediates the suppression of 168 cells.

Animals↗
PubMed1988

Epithelial component of host-tumor interactions in the orthotopic site preference of a mouse mammary tumor.

Mouse mammary tumors grow preferentially upon transplantation into intact mammary glands compared to cleared mammary fat-pads. Both sites provide stroma of the orthotopic site, but the latter lacks epithelial elements. If epithelium from enzymatically dissociated normal mammary glands is added to the tumor cells prior to injection into cleared fat-pads, tumor growth is comparable to that seen in intact mammary fat-pads. The growth-enhancing effects of normal mammary cells are not duplicated by normal kidney or liver cells. These results demonstrate that epithelial-epithelial interactions, as well as stromal-epithelial interactions, are associated with the enhanced growth of mammary tumor cells transplanted into orthotopic sites. The results also suggest that enhancement of tumor growth does not require intact tissue architecture.

Animals↗
PubMed1988

Spontaneous fusion between metastatic mammary tumor subpopulations.

This study describes a differential frequency of spontaneous fusion between metastatic and nonmetastatic subpopulations derived from a single mouse mammary tumor. Subpopulations 66, 66c14 (a variant of 66 which is resistant to both thioguanine and ouabain), 410.4, and 44FTO (a thioguanine-resistant, ouabain-resistant derivative of 410.4) spontaneously metastasize from subcutaneous and mammary fatpad sites. Subpopulations 168, 168FARO (a diaminopurine-resistant, ouabain-resistant derivative of 168), 67, 68H, and 410 do not. The ability of these subpopulation lines to fuse spontaneously in vitro was determined after coculturing a drug-resistant line with a wild-type line in nonselective media. After 16-20 h of coculture, cells were plated in the appropriate media to select for fusion products--either HAT (hypoxanthine, aminopterin, thymidine) plus ouabain or AA (alanosine, adenine) plus ouabain--to determine the number of colony-forming cells (fusion products) present per 10(4) cells plated. When both subpopulations of the pair in the fusion mixture were metastatic, a significantly greater number of fusion products was recovered than if one or both of the subpopulations in the fusion mixture was nonmetastatic, with one exception: line 410 readily fused with both 66c14 and 44FTO. Subline 410 was highly metastatic when originally isolated but lost its metastatic competence after a brief time in tissue culture.

Animals↗
PubMed1987

Analysis of tumour cell composition in tumours composed of paired mixtures of mammary tumour cell lines.

In order to quantitate the effects of tumour subpopulation interactions, we have devised a method to determine the subpopulation composition of tumours by using paired tumour cell lines able to grow in different selective media. Line 4T07 forms colonies in thioguanine but not in HAT and line 168 forms colonies in HAT but not in thioguanine. An independent technique of determining tumour cell content was used to validate this method: line 168 and 4T07 cells are distinguishable by flow cytometry after staining with propidium iodide for DNA content. Mixtures of cell suspensions prepared from each unmixed tumour, as well as from tumours arising from mixtures of these lines, were analysed by both the colony formation assay and by the DNA content assay. The colony formation assay yielded values in good agreement with the DNA content assay, but was considerably more sensitive in that it was able to quantitate minority subpopulations that constituted less than 10% of the tumour. Both methods revealed that in tumours arising from mixtures, the tumour cells were almost entirely line 4T07, even when the inoculum had contained a high proportion of 168 cells. Since line 168 cells are very tumorigenic per se, these results suggest that line 4T07 cells are capable of interfering with 168 proliferation in mixed tumours, either directly or through a host-mediated mechanism.

Aminopterin↗
PubMed1987

Pharmacokinetic comparison of intranasal, oral, and intramuscular metoclopramide in healthy volunteers.

This was a randomized, crossover study of the bioavailability and pharmacokinetics of metoclopramide given by intranasal (IN), oral (PO), and intramuscular (IM) routes. The formulations tested were 5 and 10 mg of IN gel, 10 mg PO, and 5 mg IM. The findings showed that metoclopramide follows similar absorption and elimination characteristics when given via these three extravascular routes. There were no statistically significant differences in the area under the drug concentration versus time curve (AUC) or peak metoclopramide plasma concentration (Cmax) data following PO, IM, or 10-mg IN administration. However, the 5-mg IN doses achieved an AUC that was 39.5% the AUC of the 10-mg IN dose. These data show consistent and relatively predictable metoclopramide plasma concentrations following IN administration. Further, 10-mg doses of IN and PO metoclopramide appear to be bioequivalent.

Administration, Intranasal↗
PubMed1986

Metabolic cooperation in vitro: differential ability of ouabain to uncouple normal, preneoplastic, and neoplastic mouse mammary cells.

We utilized two assays for metabolic cooperation in vitro, one in which cells were grown in monolayer and one in which the cells formed three-dimensional structures in a collagen gel matrix. Both assays required one of the test cell pair to be resistant both to ouabain and to thioguanine (deficient in hypoxanthine-guanine phosphoribosyltransferase). Normal mammary gland cells, cells from preneoplastic mouse hyperplastic alveolar nodules, and mouse mammary tumor cells were metabolically linked in vitro to the drug-resistant tumor cells. Ouabain abrogated communication between tumor cells and normal mammary gland cells and between tumor cells and preneoplastic cells but had no effect on communication between tumor cells.

Animals↗
PubMed1986

Use of drug resistance markers to recover clonogenic tumor cells from occult metastases in host tissues.

A variant of metastatic mouse mammary tumor line 410.4 was produced which is resistant to both 60 microM thioguanine and 3 mM ouabain. Occult tumor cells which result from the metastatic spread of this subline are detected by plating cell suspensions from host tissues in selective media containing thioguanine and ouabain (TO). Only the tumor cells survive and form colonies. Tumor cell colonies were recovered when as few as 6 tumor cells mixed with 1 X 10(6) lymph node cells or normal lung cells were plated in TO. Thus, the method potentially will detect the presence of clonogenic tumor cells when the host tissue contains less than 0.0006% tumor cells. Results suggest that, within 15 min of intravenous injection, less than 10% of the injected cells are clonogenic. In addition, clonogenic tumor cells can be detected in draining lymph nodes prior to the appearance of a palpable tumor implant in the subcutis.

Animals↗
PubMed1986

Metabolic cooperation between mouse mammary tumor subpopulations in three-dimensional collagen gel cultures.

A series of subpopulation lines derived from a single mouse mammary tumor were tested for their ability to interact with each other in metabolic cooperation assays in three-dimensional collagen gel cultures. Inhibition of growth in the presence of selective drug (6-thioguanine or 2-fluoroadenine) of two 6-thioguanine-resistant cell lines, 66cl4 and 44FTO, as well as a 2-fluoroadenine-resistant line, 168FAR, occurred in the presence of other sensitive cells, demonstrating the transfer of drug sensitivity to drug-resistant cells. Transfer of drug resistance was shown by using selective medium containing hypoxanthine, aminopterin, and thymidine plus ouabain in which mutual metabolic cooperation between line 66cl4 (also ouabain resistant) and "wild-type" lines is required for growth. Effective communication leading to the transfer of drug resistance and ultimate survival of both cell types occurred in mixtures containing as little as 10% of either cell type. The requirement for mutual metabolic cooperation in hypoxanthine, aminopterin, and thymidine plus ouabain medium prevented line 66 from overgrowing line 66cl4 to the extent that it did in control medium. The ranked abilities of lines 66, 410.4, and 168 to promote growth when mixed with line 66cl4 in collagen cultures in hypoxanthine, aminopterin, and thymidine plus ouabain medium were correlated with the ranked cell densities required for these same cell lines to inhibit growth of line 66cl4 by metabolic cooperation in the presence of 6-thioguanine in monolayer cultures. These ranked abilities may be related to the effectiveness with which each of these cell lines is able to form communicating junctions with line 66cl4.

Adenine↗
PubMed1985

Concomitant tumor immunity in the mammary gland.

The mouse mammary fatpad is immunologically privileged relative to the subcutis for the transplantation of nonmalignant tissues. Mouse mammary tumors, however, induce tumor-specific immunity in the mammary fatpad. Immunizing tumor cells were injected into the fatpad or subcutis at several time periods before challenge tumor cells were injected into the subcutis on the contralateral side and the time of onset of concomitant immunity was determined. Mice immunized by transplantion of tumor cells into the subcutis became resistant to challenge tumor transplants before mice immunized with tumor cells transplanted into the fatpad. By utilizing a metastatic tumor line which is resistant to thioguanine and ouabain, it was directly demonstrated that tumor cells from a s.c. implant reached the regional inguinal lymph node before tumor cells from a mammary fatpad tumor implant.

Animals↗
PubMed1985

Factors affecting growth and drug sensitivity of mouse mammary tumor lines in collagen gel cultures.

A series of mouse mammary tumor subpopulation lines were compared for growth properties and sensitivity to chemotherapeutic drugs when grown as boluses in a collagen gel matrix versus in monolayer culture. Although the cell lines exhibited characteristic rates of bolus expansion in collagen, this growth was not paralleled by an exponential increase in cell number with time. Cell boluses contained a higher proportion of cells in G0-G1 phases of the cell cycle than did the same cell lines in monolayer cultures. Histological examination revealed areas of necrosis in boluses. Thus cells growing in collagen cultures resembled cells growing as solid tumors and cells from other three-dimensional culture systems. The growth of cell boluses in collagen gel cultures was reduced nonexponentially by melphalan, methotrexate, and 5-fluorouracil in contrast to the exponential decrease in growth measured in cloning assays. The lowest concentration to which cells first responded to drug was in general similar for collagen gel assays and for cloning assays. The rank order of sensitivity of different cell lines in the two assays was identical for methotrexate (four cell lines), similar for melphalan (four of five lines), but quite different for 5-fluorouracil. In contrast to cloning assays cell boluses continued to grow, albeit at a reduced rate, in the presence of high drug concentrations. This was not due to either diminished drug availability in collagen gel or drug penetration into the bolus.

Animals↗
PubMed1984

Assessing tumor drug sensitivity by a new in vitro assay which preserves tumor heterogeneity and subpopulation interactions.

We have designed an in vitro assay to assess the influence of tumor subpopulation interactions on drug response. The assay is based upon inhibition of growth of 1 mm3-pieces of tumor embedded in a collagen gel matrix. Tumor growth is quantitated by planimetry of each colony's image, formed with a split image tracing device attached to an inverted microscope. That expansion of the colonies in collagen gel represents growth through cell replication was demonstrated by releasing and counting cell nuclei. Outgrowths from pieces of tumors produced by a series of mouse mammary tumor subpopulation lines expanded in collagen gel at a rate characteristic of each cell line: the growth rate of tumor pieces was similar to that of the corresponding tumor line embedded as a cell bolus of cultured cells, indicating that growth of pieces of tumor is due to the tumor cells rather than to stromal components. When two cell lines were grown together in collagen cultures, interactions affecting growth rate were observed. Both tumor pieces and cell boluses from cultured cells of the relatively homogeneous cell lines displayed similar, characteristic sensitivities to adriamycin (ADR) in the collagen gel assay. Advantages of the collagen assay over cloning assays are (1) preservation of potential cellular interactions which may be important in assessing tumor drug sensitivity; (2) maximization of growth of all cell populations within the tumor, as compared to growth in agar; and (3) reflection of the zonal distribution of different subpopulations within tumors; and (4) simulation of the three-dimensional growth architecture found in vivo.

Animals↗
PubMed1983

Characterization of tumor-associated lymphocytes in a series of mouse mammary tumor lines with differing biological properties.

Tumor-associated lymphocytes were isolated by isokinetic gradient separation from five related mouse mammary tumor lines with different immunological and growth characteristics. Although considerable variation in recovery rates was seen from experiment to experiment, the five tumor types were found to have reproducible and characteristic patterns of T lymphocyte subpopulations, as detected by cytotoxicity assay using monoclonal antisera to Thy-1, Lyt-1, and Lyt-2 antigens. Tumors of line 168, which are weakly immunogenic at best, had the lowest numbers of recovered ALS+, Thy1+ lymphocytes (12% and 9%, respectively), in contrast to immunogenic lines (mean 38% and 26%, respectively). Line 68H tumors, which grow after prolonged latency periods and also produce tumor cell variants in vivo, were unique in that the numbers of recovered Lyt 1+ lymphocytes exceeded the number of Lyt 2+ lymphocytes, whereas these two T cell subpopulations were either equal or Lyt 2+ cells predominated in the other faster growing, non-variant-producing tumors. No differences in T lymphocyte distribution were associated with the presence or absence of metastatic behavior. These results indicate that distinctive lymphocyte infiltrates may be characteristic of tumors with distinct biological differences.

Animals↗
PubMed1983

Significance of three-dimensional growth patterns of mammary tissues in collagen gels.

Five tumor cell lines that originated from a single mouse mammary adenocarcinoma, normal mammary tissue, a preneoplastic alveolar nodule line, and a tumor developing spontaneously from that preneoplastic line were used to study the different three-dimensional growth patterns that mammary tissues produce in collagen gel. We describe five different outgrowth morphologies, one of which may represent normal stromal tissue and infiltrating cells. One type was produced both by tumors and by normal mammary gland tissue in an age-related fashion, i.e. more outgrowths of this type were produced by mammary tissue from older mice. The outgrowth patterns for the tumor cell lines were not related to morphology in monolayer culture. Certain of the tumor lines, including one variant-producing line, produced multiple outgrowth patterns. Our results indicate that this cultivation technique may be a useful method for studying the heterogeneity of mammary tumors and may facilitate the isolation of mammary tumor subpopulations.

Aging↗
PubMed1983

Characterization of metastatic heterogeneity among subpopulations of a single mouse mammary tumor: heterogeneity in phenotypic stability.

The frequency of metastasis formed by tumor cells injected into lateral tail veins, mammary fatpads, or the subcutis are described for eight subpopulations of a single, spontaneously arising BALB/cfC3H mouse mammary tumor. These subpopulations display a spectrum of metastatic behavior from all three injection sites. The proportion of animals with metastases does not depend upon the site of primary tumor growth (i.e., mammary fatpad versus subcutis). One subpopulation can grow as lung nodules after intravenous injection but is only poorly metastatic from subcutaneous or fatpad implants. Heterogeneity among the subpopulations in the stability of the metastatic phenotype is evident. Although most of the subpopulations and their clones remained stable for periods of 2-5 years, one subpopulation rapidly lost metastatic ability within 3 months and another gradually became more metastatic over 2 years.

Animals↗