Liver metastases with 10 human colon carcinoma cell lines in nude mice and association with carcinoembryonic antigen production.

BACKGROUND: The secretion of carcinoembryonic antigen (CEA) by many colorectal tumors is associated with a worse prognosis and a greater likelihood of metastases. The exact biologic function of CEA is not known. In the literature, it has been postulated CEA may be a tumorigenicity-enhancing factor. METHODS: Ten different human colonic adenocarcinoma cell lines (RW-7213, RW-2982, LS174T, SW1116, RW-5928, DLD-2, SW-48, DLD-1, SW-480, and HCT-8) with a wide range of CEA production (from undetectable to 5200 ng/ml in culture medium) were injected into the spleens of groups of nude mice as a model for experimental hepatic metastasis. RESULTS: There was a wide range in local tumorigenicity in the spleen (from 0-90%) and in liver metastases (from 0-70%). The capacity to grow in both liver and spleen was associated with CEA production. The four cell lines that secreted the highest amounts of CEA produced the highest tumorigenicity in the spleen (67-90%) with frequent liver colonization (25-70%). The two cell lines that secreted no detectable CEA produced neither splenic tumors nor hepatic colonies. Low-level CEA production was associated with intermediate and more variable tumorigenicity. CONCLUSIONS: There was an association between CEA secretion and the ability of 10 different colorectal cell lines to grow in nude mouse spleen and liver models.

In vivo selection of a highly metastatic cell line from a human pancreatic carcinoma in the nude mouse.

A cell line with high metastatic capacity to the liver was established by sequential passages of a human pancreatic cancer cell line through the nude mouse liver. A subline, L3.5, established after five passages of the fast-growing variant (FG) of the human pancreatic cancer COLO 357 through the nude mouse liver produced extensive hepatic metastases in 100% of experimental animals when injected into the spleen. The incidence of pulmonary metastases decreased from 43% for FG to 9% for L3.5. The L3.5 cell line showed aggressive growth with almost complete replacement of the hepatic parenchyma in one third of the mean time required for the development of macroscopic metastases of FG in the liver after splenic injections of tumor cells. This study indicates that the nude mouse provides a good model for in vivo selection of metastatic cells from human pancreatic cancer. The L3.5 cell line will be valuable in the study of human pancreatic cancer metastasis, particularly in the area of survival and growth of metastatic cells in the microenvironment of the liver.

An IgG human monoclonal antibody reactive with a surface membrane antigen expressed on malignant breast cancer cells.

A human IgG3 monoclonal antibody (HMab), F86, that reacts with breast cancer cells was obtained by fusion of antibody-secreting Epstein-Barr virus (EBV)-transformed cells from a draining lymph node with the human fusion partner HMMA2.11TG/O. F86 reacts with an antigen expressed on the surface of five malignant human breast cancer cell lines and several human malignant myelomonocytic cell lines but is not detected on normal peripheral blood mononuclear cells. Studies with tissue sections of a human breast cancer line xenografted in nude mice have demonstrated that the F86 antigen is expressed both on the cell surface and in the cytoplasm of tumor cells. The F86 antigen is also expressed by the tumor cells in the original tumor specimen of a patient from whom one of the test cell lines and the xenografts were derived. Functionally, the F86 antibody does not mediate complement lysis or antibody-dependent cellular cytotoxicity in vitro. The F86 antigen could not be labeled by [35S] methionine or 125I and immunoprecipitated. The nature and expression of antigens such as that detected by the HMab F86 and how they became immunogenic and/or suppress an active immune response can be addressed through the use of HMab.

Heterogeneity of potential for hematogenous metastasis in a human pancreatic carcinoma.

Human pancreatic carcinoma, a disease with grave prognosis, frequently metastasizes to the liver, with detrimental consequences for the host. Good models of experimental metastasis for this disease are lacking. We describe a model of hepatic metastasis from the fast-growing variant (FG) of the human pancreatic carcinoma COLO 357. We also show that the slow-growing variant (SG) of COLO 357 lacks the potential for forming hepatic and pulmonary metastases following injection into the spleen of the nude mouse. This expression of heterogeneity of potential for hematogenous metastases can be exploited by pursuing studies aiming at identifying differences between the cells with and without metastatic potential.

Invasion and metastasis following orthotopic transplantation of human pancreatic cancer in the nude mouse.

A good experimental model for metastasis of human pancreatic cancer would be a valuable tool for the study of this process, which contributes significantly to morbidity and mortality. Models of experimental metastasis using injection of tumor cells into the portal or systemic circulation bypass some important steps of the metastatic process. We describe invasion and metastasis following orthotopic transplantation of human pancreatic carcinoma into nude mice. Tumor pieces were used as xenografts in this study, and metastases were observed in the regional lymph nodes, liver, lungs, and distant lymph nodes of the animals. Peritoneal implants and ascites were not observed in this study. Orthotopic transplantation of human pancreatic cancer in the nude mouse appears to be a promising model of spontaneous metastasis relevant to clinical reality.

A human breast stromal sarcoma cell line with features of malignant cystosarcoma phyllodes.

A cell line was established from a portion of a 25-cm stromal sarcoma of the left breast of a 65-year-old woman. The clinical course was rapid with tumor recurrence on the chest wall less than 1 month after mastectomy. Other cutaneous and abdominal metastases occurred shortly thereafter, and death followed within 3 months despite chemotherapy. The cultured cells, designated RW-972, produced large amounts of acid mucopolysaccharides (hyaluronic acid) and mimicked the aggressive growth characteristics seen in the patient. After injection into nude mice, the tumor grew rapidly and occasionally produced metastases. This unique cell line, RW-972, presumably derived from the stromal component of a human malignant cystosarcoma phyllodes, might be useful in studies of experimental therapy of this rare tumor type and of lobular stromal cells of breast. It may also be used to investigate hyaluronic acid production by tumor cells.

Cell culture of the mucinous variant of human colorectal carcinoma.

Two cell lines, RW-2982 and RW-7213, have been established for the first time from the mucinous variant of human colorectal carcinoma, which is a distinctive and important subtype that has a worse prognosis than the more common nonmucogenic large bowel carcinoma. Methods of establishment and observations made during 7 and 3 years, respectively, of continuous culture are described. These cell lines required 4-9 months of adaptation to tissue culture conditions before noticeable growth occurred. Both cell lines have the following unique properties: (a) growth in vitro as delicate branching three-dimensional tumor particles within a wide gel of insoluble, often translucent mucus (proteoglycan); (b) production of large quantities of carcinoembryonic antigen; (c) ability to survive or adapt to growth in media free of serum, hormones, growth factors, and all protein; and (d) tumorigenicity in multiple sites in nude mice, including liver, with especially rapid growth in the peritoneal cavity as gelatinous material that is nonadherent and noninvasive and thus resembles pseudomyxoma peritonei. Unlike other reported colorectal cell lines, these mucus-coated particulate cell lines will not readily grow as monolayers and grow much more slowly with a doubling time of 2 weeks or more. A serially transplantable tumor from the RW-7213 surgical specimen has also been maintained in nude mice since August 8, 1984. This tumor retains properties of the original specimen. Observations made on the tumor biology of mucogenic colorectal carcinoma using these cell lines are discussed.

Differential characteristics of two newly established human breast carcinoma cell lines.

Two human breast carcinoma cell lines, EP and MW, were established in culture from malignant pleural effusions. In addition to producing tumors in antithymocyte serum-immunosuppressed mice, both cell lines showed epithelial characteristics and anchorage-independent growth in soft agar. EP and MW differed in morphology (spindle-shaped versus round), chromosomal mode (hyperdiploid versus near triploid), estrogen receptor content (43.8 versus 5.1 fmol/mg protein), cloning efficiency (0.24 versus 15%), and activities (milliunits/10(6) cells) of creatine phosphokinase (25.7 versus 62.6) and lactate dehydrogenase (346.7 versus 778.5). Electron microscopy revealed that MW cells had more perinuclear filamentous material and more frequent intracytoplasmic vacuole formation than did EP cells. While having no effect on MW cells at the concentrations studied (10(-5) to 10(-11) M), beta-estradiol (10(-7) M) stimulated the growth of EP cells by 106% over the hormone-depleted control. In a variety of systems, EP was consistently the more drug sensitive of the two lines. In vitro, EP was significantly (p less than 0.001) more sensitive to methotrexate, vincristine, and 5-fluorouracil, respectively. In antithymocyte serum-mouse xenografts, EP displayed a greater response to three different dosages of a combination of cyclophosphamide, methotrexate, and 5-fluorouracil. One such dosage (cyclophosphamide, 32.0 mg/kg/day; methotrexate, 13.0 mg/kg/day; 5-fluorouracil, 190.0 mg/kg/day; for 1 day) reduced EP and MW tumor weights to 5.9 and 41% of controls, respectively. These results correlated well with the clinical responses.

Cytotoxic liponucleotide analogs. II. Antitumor activity of CDP-diacylglycerol analogs containing the cytosine arabinoside moiety.

Among events limiting the effectiveness of cancer chemotherapy are the general lack of preferential uptake of anticancer drugs by tumor cells and the occurrence of drug resistance. An approach has been undertaken to explore whether or not such events can be favorably altered or circumvented therapeutically by development of a new class of anticancer molecules, cytotoxic liponucleotide analogs. The design of cytotoxic liponucleotide analogs encompasses both biochemical and biophysical aspects of liponucleotide and glycerophospholipid structure and metabolism. Several cytotoxic liponucleotide analogs of cytidine diphosphate diacylglycerol (CDPdiacylglycerol/dCDPdiacylglycerol), containing the 1-beta-D-arabinofuranosyl moiety, were tested for antitumor activity. Multispecies ara-CDPdiacylglycerol (1-beta-D-arabinofuranosylcytosine 5'-diphosphate diacylglycerol), which contains egg lecithin-derived mixed fatty acyl chains, was more active than 1-beta-D-arabinofuranosylcytosine (ara-C), a clinically used anticancer drug, against leukemia L5178Y and P388 ascites cells in mice. At identical single doses (50 mg/kg per day times 4) administered intraperitoneally, ara-CDPdiacylglycerol prolonged the life spans of L5178Y tumor-bearing mice 93%, while ara-C prolonged life by 18%. Ara-CDPdiacylglycerol increased life spans of P388 tumor-bearing mice by 357% at doses of 50 mg/kg per day times 4; the maximum increase with ara-C was 159% (85 mg/kg per day times 4). Against a P388 ara-C-resistant cell line (P/Ara-C, kinase deficient) in mice, ara-CDPdiacylglycerol prolonged survival times by 34% at a dose of 50 mg/kg per day times 4 and by 55% at 75 mg/kg per day times 4; the drug was not active against two other ara-C-resistant murine leukemia mutants (CA 55, CA5b). With cell line-derived human colon carcinoma HCT-15 grown in mice immunosuppressed with anti-thymocyte serum, ara-CDPdiacylglycerol at a single daily dose of 50 mg/kg per day times 4 significantly reduced tumor weights to 21% of the controls; the same dose schedule of ara-C caused no observable reduction of tumor weights. Results of these preliminary antitumor evaluations indicate that cytotoxic liponucleotide analogs should be investigated further to determine their potential as antineoplastic molecules.

Chemotherapy of cell-line-derived human colon carcinomas in mice immunosuppressed with antithymocyte serum.

An in vivo model is described for assessing the antitumor activity of chemotherapeutic agents. Tumors derived from human colon carcinoma cell lines injected into antithymocyte serum (ATS) immunosuppressed mice were used. In this system, both antitumor effects and host toxicity can be quantitated, permitting calculation of a Therapeutic Index. Compared with other xenograft models, the present system is simple, experiments are completed in less than 2 weeks, and the use of cultured cell lines allows in vitro studies to be performed. The in vitro sensitivities of one colon cell line to 22 chemotherapeutic agents and of four cell lines to three agents is reported. Four drugs used in treating colon cancer (Mitomycin C, 5-FU, BCNU, and methyl-CCNU) show antitumor activity in vivo in this system. Each has a low therapeutic index. Further work with this model is indicated, with the goal of finding new drugs with high Therapeutic Indices.