Induction of mammary gland tumor in female Sprague-Dawley rats with LA7 cells (original) (raw)
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Induction of mammary gland tumor in female Sprague
2010
The current methods for tumor induction in breast cancer research animal models are time-consuming, hazardous, expensive, sometimes irreproducible and inconvenient. We successfully developed a new, simple and cost-effective method in developing solid mammary gland tumor in female Sprague-Dawley rat using LA7 rat mammary tumor cells. Tumors developed in 7-8 weeks old rats within 6 to 8 days of subcutaneous injection of LA7 cells into the mammary gland pad. Tumor size increased exponentially for four weeks. Histopathology examination confirmed that the induced tumors were adenocarcinomas. Evaluation of blood enzymes showed significantly higher (P < 0.005) serum alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in tumor-bearing than in normal rats. This LA7 cell-induced rat mammary gland tumor model may be useful for studies in breast cancer drug or nutraceutical research and development.
Journal of Tissue Culture Methods, 1997
Mouse mammary glands respond to growth promoting hormones in organ culture. In the presence of insulin, prolactin, aldostrone, and hydrocortisone, the glands exhibit extensive proliferation within 10 days of culture mimicking the mammary alveolar structures observed during pregnancy. However withdrawal of prolactin and steroids from the medium for an additional 14 days results in the disintegration of the alveolar structures
Characterization of Breast Cancer Progression in the Rat
Annals of the New York Academy of Sciences, 2008
The incidence of breast cancer is continuously increasing worldwide. This increasing trend is attributed partly to the fact that a considerable number of cases are related to environmental factors and partly to the little information available on the early changes that occur during mammary gland carcinogenesis. To characterize some of these early cellular changes, breast cancer was induced in female rats using a single intragastric dose of the environmental carcinogen 7,12-dimethylbenz[a]anthracene (DMBA; 80 mg/kg body weight). Mammary gland tissues of control and DMBA-treated rats were processed for routine histopathological examination and immunohistochemical analysis using an antibody specific for the proliferating cell nuclear antigen (PCNA). Microscopic examination of all mammary glands of DMBA-treated rats revealed a wide range of preneoplastic stages in addition to the well-characterized benign and malignant tumors that developed. The first stage was characterized by slightly dilated terminal ducts with accumulation of dead cells. This was designated the stage of cell death. Then, stages of hyperplasia, dysplasia, and carcinoma in situ followed. Immunohistochemical localization of PCNA in these preneoplastic lesions revealed an initial decrease followed by a gradual increase in the labeling index of PCNA. In conclusion, the DMBA-treated rats provide a useful model to dissect the early changes that occur during the multistep process of mammary gland carcinogenesis.
Animal models for breast cancer
Mutation research, 1995
Rodent mammary tumors induced by chemical carcinogens have proven to be very useful in the genetic analysis of initiation, promotion and progression of mammary carcinogenesis. We are studying rat mammary carcinomas induced by the chemical carcinogen, N-nitroso-N-methylurea. The earliest genetic event observed in the mammary gland is the activation of Ha-ras oncogenes, which is followed by promotion of the initiated cells by hormones involved in puberty. Preferential amplification of the mutated Ha-ras allele, of PRAD-1 and IGF2, loss of expression of the mitogenic growth factor gene, MK, and mutation in the tumor suppressor gene, p53, are seen in the mammary tumors during tumor progression.
Differential characteristics of two newly established human breast carcinoma cell lines
Cancer research, 1985
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...
In Vitro Cellular and Developmental Biology--Animal, 2000
Identification of clones in primary tumors responsible for proliferation, invasion, and metastasis was carried out. Four different aneuploid established cell lines derived from a ductal infiltrating mammary rat tumor induced by 7,12-dimethylbenz[a]anthracene were studied for proliferative and growth features in vitro and for tumorigenic and metastatic potential in vivo in nude mice. Clones, named RM1, RM2, RM3, and RM4, were characterized by different proliferative activity. Clone RM] showed the highest proliferative activity by both tritiated thymidine incorporation and S-phase flow cytometry, followed by clone RM4. Conversely, clones RM2 and RM3 showed a lower proliferation rate. Growth-promoting activity, tested on 3T3 Swiss cells, was high in all clones, although RM1 showed significantly lower growth factorsreleasing activity. Nude mice tumorigenesis demonstrated a strong tumor induction of line RM1 (100% of the mice after 47 + 7 d) and a slightly lower tumor induction of line RM4 (70% of the mice after 69 ---9 d). Line RM3 showed tumor induction in 40% of the mice after 186 + 16 d. Lines RM2 showed no tumor induction. Metastasis occurred in mice treated with line RM1 only. Therefore, tumorigenesis and metastasis correlate with proliferation but not with the release of growth factors. In conclusion, flow cytomctry monitoring of clones from heterogeneous primary tumors proved to be a suitable model for the study of in vivo malignancy and in vitro proliferation.
Rat Models of Premalignant Breast Disease
Journal of Mammary Gland Biology and Neoplasia, 2000
While a number of agents have been shown to induce mammary carcinogenesis in the rat, premalignant stages of the disease have been best characterized in chemically-induced models, specifically those initiated by either 7,12 dimethylbenz[α]anthracene (DMBA)4 or 1-methyl-1-nitrosourea (MNU). In general, it appears that epithelial cells in mammary terminal end buds or terminal ductules are the targets of carcinogenic initiation, and that a series of morphologically identifiable steps are involved in the development of mammary carcinoma. The premalignant steps include ductal hyperplasia of the usual type and carcinoma in situ of the cribriform or comedo type; atypical ductal hyperplasia has not been reported. Thus the histogenesis of lesions occurring in chemically induced mammary carcinogenesis in the rat is similar to that observed in the human; although, the spectrum of lesions observed in the rat is limited. Opportunities to investigate the biological and molecular characteristics of premalignant breast disease in the rat are presented.
International Journal of Cancer, 1994
Three stable carcinoma cell lines, designated RM22-F5, RM17 5R, and RM 1-4, were established from spontaneously occurring mammary carcinomas in old, outbred, female Wistar rats. The RM22-F5 and RM 17-SR cells were keratin-positive and formed epithelial monolayers, whereas RMI-4 cells exhibited a spindle-like morphology and intense vimentin staining. When injected into nude mice, RM22-F5, RM17-5R and RM1-4 cells formed well-differentiated, poorly differentiated and undifferentiated carcinomas, respectively. The relative growth rates of the tumor cells in vitro were RM1-4 > RM22-F5 > RM17-5R. The growth of RM22-F5, but not of RM17-5R and RM1-4 cells, was significantly stimulated by insulin, epidermal growth factor, dexamethasone, 17β-estradiol and progesterone in vitro. Ovariectomy reduced the growth of RM22-F5 cells in vivo and these cells (but not RM1-4 or RM17-5R) were estrogen-receptor (ER)-positive. None of the lines were positive for the progesterone receptor (PR). Spontaneous lung and lymph-node metastases were observed in nude mice injected with RM22-F5 or RM17-5R cells, respectively. In contrast, RM1-4 cells were non-metastatic but invasive. Karyotype analysis revealed that RM22-FS cells were hyperdiploid, RM 17-SR were hypotetraploid, and RM1-4 were diploid with a sizeable insertion in chromosome I. A point mutation in codon 12 (G to A transition) and loss of the normal aliele of the H-ras-1 gene was detected in the DNA from RM22-FS cells. No p53 mutations were apparent in any of the cell lines. The results indicate that RM22-F5 cells are hormone-dependent with an ER+/PR− phenotype, while the RM 17-SR and RM1-4 lines are hormone-independent and ER−/PR. These cell lines exhibit the spectrum of biological properties and genetic alterations observed in human breast cancers and may, therefore, be novel and useful models for understanding sporadic breast cancer in post-menopausal women.
Growth of human breast carcinomas in nude mice and subsequent establishment in tissue culture
1980
slicing (9, 14), treatment with trypsin (13), and collagenase (1). A different approach was taken by Cailleau et a!. (3) who developed a number of cell lines from pleural effusions. Using this same technique of culturing cells from pleural effusions, Soule et a!. (19) developed a human breast carcinoma cell line that has been reported to have an estradiol receptor (2) and to produce a-lactalbumin (18). In this paper, we report on the establishment of 4 transplant able human breast tumors in the nude mouse and the devel opment of 3 cell strains from 2 of these transplantable tumors. MATERIALS AND METHODS Nude Mouse Colony. A colony of nude mice on the BALB/ c background was developed from breeding stock purchased from Bomholtsgaard, Ltd., Ry, Denmark. The colony of mice is maintained in isolation, and all food, water, cages, and bedding are sterilized. The cages are capped with sterile filter barriers (Maryland Plastics, Inc., New York, N. V.). The colony has been described in detail elsewhere (16). Breast tumor tissue from local hospitals was received in sterile F-i 2 medium supplemented with 10% human serum. A portion of each tumor was prepared for histological evaluation of tumor pathology, and a second portion was frozen for biochemical assays. The remaining tumor tissue was finely minced, rinsed for 5 mm in antibiotics (streptomycin and peni cillin), and injected with an 18-gauge needle s.c. into the flank of female nude mice. An estrogen pellet was implanted on the contralateral side[each pellet contained 25 mg of 17@-estradiol (Sigma Chemical Co., St Louis, Mo.)]. In preliminary studies, tumors were injected into mice with and without pellets; tumors routinely grew better in animals with pellets.4 It was not known if the nude mice produced enough estrogen to support those tumors which required or were growth responsive to estrogen; some 40 to 50% of human breast tumors are dependent upon ovarian hormones for growth (7). The size of the tumor was determined at biweekly intervals by caliper measurement of the s.c. tissue mass. The tumor was transplanted when it reached a size of approximately 1.5 cm. Tissue Culture. Some of the original tumor, when available, or the mouse-passaged tumor was cultured after the method originally outlined by Lasfargues and Ozzello (9). Following external sterilization of the tumor in 70% alcohol, the tissue was trimmed of fat and minced with sharp scissors. This permits the tumor cells to spill out into the medium. The following day, the supematant containing the spilled tumor cells was trans ferred to a second tissue culture dish. Any fibroblast contami nation or other cellular contaminants that were present in the tumors grown in the nude mice were of murine origin and were readily removed by treatment of the culture with rabbit anti