An efficient method for culturing human breast carcinoma to evaluate antiblastic drug activity in vitro: experience on 136 primary cancers and on 116 recurrences

An Efficient Method for Culturing Human Breast Epithelium: Analysis of Results

We have examined the possibility of obtaining primary cultures from breast tissue utilizing a method especially developed for breast epithelium. The number of specimens able to grow in culture was very high: 82.8%, 64.3 %, 75.0 % and 77.8 %, respectively, for primary breast cancer, skin recurrences, inflammatory breast cancer and normal breast tissue. In our experience, growth was not related to menopausal status or histopathologic type, whereas for skin recurrences, a prior pharmacologic treatment (chemotherapy) of the patient enhanced the growth capacity of the tissue. This culture method could help to study the basic biology of breast epithelia and to improve the chemotherapy approach of breast cancer patients.

Combined 4-hydroxy-ifosfamide and vinorelbine treatment in established and primary human breast cell cultures

BACKGROUND

Vinorelbine and ifosfamide are active drugs against breast cancer, but the best treatment schedule has yet to be defined by preclinical or clinical studies. The antitumor activity of 4-hydroxy-ifosfamide (4-OH-IF), the active form of ifosfamide, and vinorelbine (VNB) and their interaction were investigated in two established breast cancer cell lines (MCF-7 and BRC-230) and in 10 primary breast cancer cultures.

MATERIALS AND METHODS

Cytotoxic activity was evaluated by a highly efficient clonogenic assay (HECA). The median-effect principle was applied to evaluate synergistic and antagonistic interactions and the corresponding combination index values were calculated. Cell cycle perturbations were analysed by flow cytometry.

RESULTS

In MCF-7 and BRC-230 cell lines the sequence VNB for 4 hours followed by 4-OH-IF for 24 hours produced an antagonistic effect. Conversely, the inverse sequential scheme, 4-OH-IF-->VNB provided synergistic effects on both cell lines. The synergism was associated with a strong block in the G2-M phase. Synergistic activity of 4-OH-IF-->VNB sequence was confirmed in 7 of 10 primary breast cancer cultures.

CONCLUSIONS

In conclusion, the sequence 4-OH-IF-->VNB appeared to be the most effective scheme both in established cell lines and in primary breast cancer cultures.

Establishment and characterisation of new cell lines from human breast tumours initially established as tumour xenografts in NMRI nude mice

Human breast cancer cell lines are required as models for use in the understanding of breast carcinoma, and for improving the ability of cell screens to detect appropriate anti-cancer agents. Four human breast cancer cell lines (MT-1, MaTu. MT-3 and MC4000) were established from human tumour xenografts grown in nude mice. All the lines were shown to be of human origin by karyotype analysis, were epithelial in morphology by both light and electron microscopy, were positive for cytokeratin 18, and were free from mycoplasma, bacterial, yeast and fungal contamination. All of the new lines were shown to be ER and PgR negative, while using the same procedures (i.e. radioligand binding and immunohistochemical staining) the positive control cell line MCF-7 was shown to be positive. MaTu had been previously reported as ER and PgR positive in vivo and it may be that this characteristic had been lost due to in vitro selection pressures. The growth rates of all the new breast cancer cell lines were similar and within the limits required for incorporation into a panel for screening anti-cancer drugs by a microtetrazolium based, colorimetric growth inhibition assay. Three of the lines (MT-1. MaTu and MC4000) were also able to grow into macroscopic colonies for use in a non-agar clonogenic assay. In addition, both MT-1 and MaTu formed spheroids and were clonogenic in soft-agar. The new lines demonstrated a wide range of sensitivities to anticancer agents commonly used in the treatment of breast cancer, and together with their corresponding xenografts are providing additional systems for the evaluation of new compounds.

Selective growth of freshly isolated human breast epithelial cells cultured at low concentrations in the presence or absence of bone marrow cells

In this study, we show that conditions previously found to promote the selective growth of human breast epithelial cells (HBEC) in serum-free primary cultures established from normal or malignant tissue can be extended to cultures initiated at low seeding densities (< 5000 cells/cm2). The epithelial nature of the cells produced was documented by their positive staining with antibodies specific for keratins 8, 14, and 18, and 2 antibodies that recognize epithelial-specific antigens (Ber-EP4 and HB8630). HBEC growth was not affected, either positively or negatively, by the use of a medium containing a combination of fetal calf and horse serum, which promotes the growth of many types of stromal cells and associated hematopoietic precursors, or by the inclusion in the initial cell suspension of marrow cells at HBEC to marrow cell ratios typical of bone marrow samples from patients with metastatic breast cancer. The presence of fibroblast feeders from a variety of sources enhanced the growth of HBEC to different degrees. In cultures initiated with low numbers of cells obtained from samples of breast carcinoma, HBEC growth was generally reduced by comparison to cultures of normal HBEC. With the detection methods used, it was not possible to determine the extent to which this decreased growth was due to a reduced frequency of malignant HBEC with in vitro precursor activity, or the presence of reduced numbers of residual normal HBEC precursors, or both. However, preliminary data indicate that this approach also allows the detection of some breast carcinoma cells with proliferative ability that are present in the marrow or pleural effusions of some breast cancer patients. These studies demonstrate the feasibility of detecting normal and malignant HBEC with growth potential when these are cultured at low density and/or as rare contaminants of marrow cell suspensions, and provide a starting point for their further characterization.

In vitro activity of taxol and taxotere in comparison with doxorubicin and cisplatin on primary cell cultures of human breast cancers

The in vitro activities of taxol and taxotere in comparison with cisplatin and doxorubicin were assessed in 30 primary tumor cultures from human breast cancers. Both taxanes were much more potent than cisplatin and doxorubicin. Taxotere was 3.1; 296, and 9.6-fold more cytotoxic than taxol, cisplatin, and doxorubicin respectively. The cytotoxic activity observed in our experiments confirms the potential clinical relevance of the two taxanes in the management of breast cancer.

Establishment and characterization of a new cell line from primary human breast carcinoma

A new cell line (BRC-230) was established from surgical material of primary ductal infiltrating breast carcinoma. The epithelial nature of this cell line was confirmed by ultrastructural analysis and demonstrated the retention of structural properties characteristic of the original tumor. The BRC-230 cell line induced tumor in athymic Cr1:nu/nu(CD-1)BR nude mice, it possessed an abnormal karyotype with a modal chromosome number between 60-61 with eight recurrent marker chromosomes, and it presented a doubling time of 30.5 hr. Scatchard analysis demonstrated that both primary tumor and BRC-230 cells were estrogen and progesterone receptor negative. Immunoenzymatic and radioimmunoassays showed a production of marker antigens (CEA, TPA, CA125, CA15-3, CA19-9) which was similar in the patient's serum and BRC-230 cells. The in vitro drug sensitivity assay of the cell line and of the parental tumor tissue showed overlapping results to all tested antiblastic drugs. BRC-230 cells were resistant to 4-Idroperoxy-cyclophosphamide, Idarubicinol, Mitoxantrone, Etoposide, 4'Epidoxorubicin, and Doxorubicin, showing a multiple drug resistance phenotype. Amplification or rearrangement of Her-2neu, Ha-ras, and C-myc genes was observed neither in the original tumor nor in BRC-230 cells; the mdr-1 gene was also present in a single copy. We conclude from these studies that the BRC-230 cell line maintains the same characteristics as the original tumor and may provide us with a good model to study in vitro the biology of drug resistance of breast cancer.

Application of the adenosine triphosphate-cell viability assay in human breast cancer chemosensitivity testing: a report on the first results

Chemosensitivity testing in vitro of breast cancer has been difficult because of small tumour volume, an even smaller yield of viable cells after disaggregation, and the low evaluability rate and sensitivity of current assays. We have employed an alternative approach that quantitates intracellular adenosine triphosphate (ATP) as a measure of cell viability. This ATP-cell viability assay (ATP-CVA) determines in vitro tumor cell viability after exposure to chemotherapeutic agents in comparison to untreated controls following 6 days of incubation. Sixty-one fresh breast cancer specimens upon testing yielded an evaluability rate of 95%. Forty-seven of the tumors were untreated primary breast cancers, the remaining 14 were from patients with metastatic disease. Correlations of in vitro drug sensitivity with in vivo response were obtained for 17 treatment regimens in 14 patients with metastatic breast cancer. The level of sensitivity was 90% and the specificity 86%. These preliminary data demonstrated the ATP-CVA to be a practical in vitro approach to breast cancer testing. It will require a larger clinical study for confirmation.

Epirubicin. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic use in cancer chemotherapy

Epirubicin is the 4' epimer of the anthracycline antibiotic doxorubicin, and has been used alone or in combination with other cytotoxic agents in the treatment of a variety of malignancies. Comparative and noncomparative clinical trials have demonstrated that regimens containing conventional doses of epirubicin achieved equivalent objective response rates and overall median survival as similar doxorubicin-containing regimens in the treatment of advanced and early breast cancer, non-small cell lung cancer (NSCLC), small cell lung cancer (SCLC), non-Hodgkin's lymphoma, ovarian cancer, gastric cancer and nonresectable primary hepatocellular carcinoma. Recently, dose-intensive regimens of epirubicin have achieved high response rates in a number of malignancies including early and advanced breast cancer and lung cancer. The major acute dose-limiting toxicity of anthracyclines is myelosuppression. In vitro and clinical studies have shown that, at equimolar doses, epirubicin is less myelotoxic than doxorubicin. The lower haematological toxicity of epirubicin, as well as the recent introduction of supportive measures such as colony-stimulating factors, has allowed dose-intensification of epirubicin-containing regimens, which is particularly significant because of the definite dose-response relationship of anthracyclines. Cardiotoxicity, which is manifested clinically as irreversible congestive heart failure and/or cardiomyopathy, is the most important chronic cumulative dose-limiting toxicity of anthracyclines. Epirubicin has a lower propensity to produce cardiotoxic effects than doxorubicin, and its recommended maximum cumulative dose is almost double that of doxorubicin, thus allowing for more treatment cycles and/or higher doses of epirubicin. In summary, dose-intensive epirubicin-containing regimens, which are feasible due to its lower myelosuppression and cardiotoxicity, have produced high response rates in early breast cancer, a potentially curable malignancy, as well as advanced breast, and lung cancers. Furthermore, there is evidence to suggest that improved response rates can improve quality of life in some clinical settings, but whether this leads to prolonged survival has not yet been determined. Recently implemented supportive measures such as colony-stimulating factors, prophylactic antimicrobials and peripheral blood stem cell support may help achieve other potential advantages of dose-intensive epirubicin-containing regimens such as reductions in morbidity and length of hospital admissions.

In vitro potentiation by lonidamine of the cytotoxic effect of adriamycin on primary and established breast cancer cell lines

Lonidamine is a new potential chemotherapeutic agent, relatively non-toxic, that can positively modulate the efficacy of several antineoplastic drugs. We evaluated the response of two established human breast cancer cell lines (MCF-7 and BRC-230) and of 20 primary breast cancer cell lines to lonidamine, either alone or in combination with adriamycin, the drug most widely used in the management of breast cancer. Different schedules were tested by varying either concentration of the drugs (LND: 10-150 micrograms/ml; ADM: 0.10-0.15 micrograms/ml), or time of exposure (1-96 hours), or sequence of administration (ADM-->LND; LND-->ADM; ADM+LND). Our results indicate slight sensitivity of the cell lines to lonidamine when used alone, whereas an increase of efficacy was noted when lonidamine was added for at least 24 hours after a 4 hour exposure to adriamycin. Such efficacy was significantly greater than that expected from an additive effect between the two drugs. We conclude that lonidamine, when given according to an appropriate schedule, enhances, in vitro, the efficacy of adriamycin. A correct employment of lonidamine in the management of breast cancer might therefore potentiate the therapeutic effect of adriamycin.