Characterization of cancer cell lines established from two human metastatic breast cancers

Summary Cell lines are valuable resources for the study of the malignancy and potential therapy of human breast cancer. A major problem with adapting fresh breast tumor specimens to grow in vitro is contamination by fibroblasts. Previously, we have reported a technique to overcome this problem (Nayak, S. K; Dillman, R. O. Clin. Biotechnol. 3:237–242; 1991). We have recently established two new breast cancer cell lines, HH315 and HH375, that were derived from abdominal and supraclavicular lymph node metastases from two patients. They were characterized by (1) growth kinetics; (2) staining with monoclonal antibodies (MoAbs) to cytokeratin-19, epithelial membrane antigen (EMA), anticarcinoembryonic antigen (CEA), breast cancer antigen 1 (BRST-1), breast cancer antigen 2 (BRST-2), Her2/neu, and p53; (3) expression of domains of urinary plasminogen activator (uPA), neural cell adhesion molecule (NCAM), and haptoglobin (Hp) (Harvey et al., 1997); and (4) karyotypic analysis. Growth kinetic studies showed that doubling times for both lines ranged from 48 to 96 h. These two cell lines were found to have characteristics of the metastatic breast cancer cells. Both lines stained positive with MoAbs to cytokeratin-19 and EMA, thus confirming their epithelial origin. They also strongly reacted with the pan-breast carcinoma MoAbs BRST-1 and BRST-2, and carcinoembryonic CEA MoAb. Both cell lines overexpressed the oncogene proteins Her2/neu and p53. The tumor cells were negative for estrogen and progesterone receptors. HH315 cells were poorly differentiated, whereas the HH375 cells exhibited adenocarcinoma morphology. Both cell lines showed intense cell surface and some cytoplasmic staining for uPA, NCAM, and Hp domains, which is a characteristic of malignant neoplasms (Harvey et al., 1997). The HH375 cell line showed two cell types, of which 60% were hyperdiploids with 60–70 chromosomes and 5–10 marker chromosomes. The remaining cells were polyploid with more than 200 chromosomes. Cell line HH315 consisted of only a polyploid population. These cell lines may be useful in breast cancer research.     

Development and characterization of new immortalized human breast cell lines

New human breast cell lines were developed from metastatic breast cancer tissues and normal breast tissues. Primary cultures were initiated from cellular outgrowths of explanted tissues or from mechanically isolated cells in two serum-free media. Cell cultures derived from both cancer and normal tissues were immortalized with pRSV-T plasmid to generate permanent breast cell lines that exhibited an epithelial morphology. Cell lines generated in this study were characterized with respect to morphology, growth rate, karyotype, presence of specific genes, and the expression of epithelial and breast markers. The cell lines expressed the epithelial cell markers, cytokeratins 8 and 18, and retained the capacity to produce human milk fat globulin. They also express the BRCA-1, erbB2, and EGF receptor genes and possess the H-ras, K-ras, and p53 genes. Preliminary data showed that one of the new cancer cell lines was highly sensitive to the cytotoxic action of taxol. It is envisioned that the new breast cell lines will be useful as targets for identification of therapeutic agents against breast cancer and as models for carcinogenesis studies. This revised version was published online in June 2006 with corrections to the Cover Date.     

抗卵清蛋白单克隆抗体杂交瘤细胞株的制备

为制备分泌抗卵清蛋白的杂交瘤细胞,以高纯度的卵清蛋白抗原免疫BALB/c小鼠,取其脾脏细胞和Sp2/0骨髓瘤细胞融合,获得杂交瘤细胞,用ELISA间接法检测上清液中的抗卵清蛋白抗体效价,经3次单克隆化筛选,获得5株分泌抗卵清蛋白抗体的杂交瘤细胞株。     

Cellular localization of tissue factor in human breast cancer cell lines

Expression of tissue factor (TF), the cellular receptor of clotting factor VII/VIIa, is a feature of certain malignant tumours. The TF gene has been classified as an immediate early gene responsive to serum and cytokines. Thus, the regulation of TF gene expression seems to play a role in cell growth. Recently, we have shown that constitutive TF expression in MCF-7 breast cancer cells is modulated by such growth factors as EGF, TGFα, and IL-1. The present study deals with the immunocytochemically detectable cellular distribution of TF in human breast cancer cell lines MCF-7 and MaTu stimulated by EGF and TGFα. In MCF-7 cells growing logarithmically, stimulation led to a significant increase of TF mRNA after 2 h (in situ hybridization, Northern blot) and to maximum TF expression after 6 h (immunohistochemistry). When decorated by monoclonal antibodies, TF protein showed a pronounced localization at ruffled membrane areas, cell edges, and processes of spreading cells after 6 and 20 h. In more flattened cells TF was concentrated in peripheric lamellae and microspikes communicating with neighbouring cells. After epithelial colony pattern had established, TF was predominantly accumulated at the intercellular boundaries. The vary same distribution patterns as seen in MCF-7 cells were true for the stimulated MaTu cell line. The dynamics and cellular distribution patterns of stimulated TF expression support the hypothesis that TF could be of importance for morphogenic events associated with the growth and differentiation of breast cancer cells in culture.     

Development and characterization of breast carcinoma cell lines as in vitro and in vivo models for breast cancer diagnosis and therapy

Summary To establish a model system for preclinical radioimmunotherapy studies, attempts were made to graft 16 different human breast carcinoma cell lines into BALB/c nu/nu (nude) mice. Nine produced serially transplantable tumors growing at a variable rate, whereas seven failed to do so. Conversely, three new cell lines were established in monolayer culture from transplantable human breast tumors in nude mice. Twelve selected tumors and their corresponding cell lines were characterized for DNA ploidy, % S-phase, and breast epithelial mucin expression by immunohistochemistry and flow cytometry. A wide diversity of these cellular characteristics were found in that each tumor was unique and distinct from the others. DNA ploidy differed among the tumors but was not affected by switching between in vitro to in vivo growth. Some tumors expressed similar levels of the breast mucin both in vitro and in vivo, whereas most expressed lower levels as transplantable tumors. There was a good correlation between immunohistochemical and flow cytometric determination of surface and cytoplasmic mucin expression, and with both techniques estrogen and progesterone receptor positive tumors had significantly higher levels of mucin expression than receptor negative tumors. These 12 transplantable breast tumors, with their corresponding cell lines, provide an excellent model system for testing radioimmunotherapy and other therapeutic reagents because they exhibit diverse phenotypic characteristics that represented a mini-population of breast cancer patients’ tumors, allowing assessment of the effect of therapy when confronted with different breast tumors’ genotype and phenotype.     

Antiproliferative activity of L-asparaginase of Tetrahymena pyriformis on human breast cancer cell lines

Purified L-asparaginase of Tetrahymena pyriformis is a multi-subunit enzyme exhibiting protein kinase activity as well. The enzyme's L-asparaginase activity is affected by its phosphorylation state. Both native and dephosphorylated L-asparaginase show antiproliferative activity on three breast cancer cell lines (T47D, BT20 and MCF-7) and on Walker 256 cells. These cells do not possess measurable L-asparaginase or L-asparagine synthetase activity. When T47D cells are treated for different times with L-asparaginase and then placed in fresh medium, the growth of cells treated for 1, 3, or 6 hours is initiated and parallels control curve, while the growth of cells treated for 24 or 48 hours with L-asparaginase stays at the same inhibitory level (24 h treatment) or continues to drop (48 h treatment). Addition of D-asparagine, a competitive inhibitor of T. pyriformis L-asparaginase, counteracts the antiproliferative activity of L-asparaginase, indicating that L-asparaginase and not the kinase activity is responsible for that effect.     

Long-term human breast carcinoma cell lines of metastatic origin: Preliminary characterization

Summary Nineteen human breast carcinoma cell lines have been established as continous cultures during the past 6 years in our laboratory. This preliminary report is designed to list the lines by their designated code numbers (MDA-MB) and present a brief summary of their morphological, cytogenetic and biochemical characteristics. Sixteen of our lines were obtained from pleural effusions, two from brain metastases, and one from pericardial fluid. All lines have been shown to be distinct entities and are uncontaminated by HeLa cells or each other. A lq marker chromosome is present in all but one of the lines examined. This research was sponsored by the National Cancer Institute Contract NO1-CB-23869; Institutional Grant 5S 07 RR 5511-15 awarded by the Division of Research Resources, and a Kelsey-Leary Grant NO 974.     

三苯氧胺对乳腺癌和宫颈癌细胞增殖的影响

目的：研究三苯氧胺(tamoxifen,TAM)对人乳腺癌Bcap-37和宫颈癌HeLa细胞增殖的影响并探讨其可能的机制。方法：采用细胞培养、细胞计数、MTT、流式细胞术和激光共聚焦显微镜技术。结果：TAM(10^-6mol／L)使Bcap-37细胞的生长曲线下移,使HeLa细胞的生长曲线上移。TAM(10^-8～10^-6mol／L)剂量依赖性的抑制Beap-37细胞的增殖,促进HeLa细胞的增殖作用。TAM(10^-6mol／L)使Bcap-37细胞发生凋亡,凋亡率达到97．5％,而使HeLa细胞周期由G1期加速向S期转化,G1期的DNA含量由对照组的55．5％下降到加药组的32．8％,S期的DNA含量由对照组的29．0％上升到加药组的49．4％。激光共聚焦检测到TAM(10^-6mol／L)可使Bcap-37细胞和HeLa细胞内的Ca^2 浓度显著升高。结论：TAM可以通过调节细胞周期各阶段DNA含量和胞内Ca^2 浓度水平,从而调节Bcap-37细胞和HeLa细胞的增殖活动,提示使用TAM治疗乳腺癌时可能会对子宫颈产生副作用。     

Newly established cell lines fromDrosophila larval CNS express neural specific characteristics

Summary From the central nervous system ofDrosophila melanogaster 3rd instar larvae, eight continuous cell lines have been established (named ML-DmBG1 to 8). Using ML-DmBG2, single colony isolation was carried out and six colonial clones were obtained. All reacted to the antibody to horseradish peroxidase, which is a neuronal marker in insects. Acetylcholine, a known neurotransmitter inDrosophila, was detected in three of the colonial clones by high performance liquid chromatography. Therefore, it is concluded that the established colonial clones are neural cells originating in the larval central nervous system. Among them, some variation was observed with respect to morphology, acetylcholine content, and reactivity to anti-HRP. The variation may reflect the heterogeneity of cells composing the central nervous system.     

Expression of recombinant anti‐breast cancer immunotherapeutic monoclonal antibody in baculovirus–insect cell system

The anti‐breast cancer monoclonal antibody (mAb) BR55 was expressed in the baculovirus–insect cell expression system, which is advantageous because of its high production capacity, cell culture flexibility and glycosylation capability. The baculovirus–insect cell expression system was successfully established for production of mAb BR55 and mAb BR55 fused with the KDEL (Lys–Asp–Glu–Leu) endoplasmic reticulum (ER) retention signal (mAb BR55K). The heavy chain (HC) and light chain (LC) genes of mAb BR55 were cloned under the control of the polyhedrin (P_PH) and P₁₀ promoters, respectively, in the pFastBacDual vector. The antibody gene‐expression cassettes carrying both the HC and LC genes were transferred into a bacmid in Escherichia coli (DH10Bac). The bacmid carrying the expression cassettes was transfected into Sf9 insect cells to generate baculovirus expressing mAb BR55 and BR55K. Western blot analysis confirmed the expression of mAb BR55 and BR55K in baculovirus‐infected insect cells. Cell direct enzyme linked immunosorbent assay (ELISA) showed that both mAbs from insect cell lysates or cell culture medium bound to MCF‐7 human breast cancer cells. Both mAb BR55 and BR55K were successfully purified using a Protein A affinity column. Collectively, these results suggest that the anti‐breast cancer mAb BR55 can be expressed, properly assembled and purified from the baculovirus expression system, which can serve as an alternative system for antibody production.     

Characterization of a monoclonal antibody reactive with a glycolipid antigen expressed by tumorigenic and certain immortalized,non-tumorigenic rat esophageal epithelial cell lines

A monoclonal antibody (mAb 5G) was produced against a tumorigenic rat esophageal epithelial cell line, designated B2T. Using an enzyme-linked immunosorbent assay, immunofluorescence assay (IFA), thin-layer chromatography (TLC) and immunoperoxidase staining, it was found that mAb 5G reacted specifically with a glycolipid antigen expressed by three tumorigenic rat esophageal epithelial cell lines, and two out of the three nontumorigenic, immortalized rat esophageal epithelial cell lines tested; but did not react with primary cultures of normal rat esophageal epithelial cells or fibroblasts. mAb 5G did not bind to rat respiratory tract carcinoma cell lines, to immortalized rat tracheal epithelial cell lines, or to primary cultures of normal rat tracheal epithelial cells. In addition, mAb 5G did not react with any of the human or mouse cell lines tested. In IFA experiments, mAb 5G stained imprints prepared from in vivo propagated B2T tumor tissues, but did not react with normal rat esophageal, tracheal, lung, liver, and kidney tissues. The antigen was identified by TLC as a neutral glycolipid, consisting of two bands, withR _F = 0.45 and 0.41, which migrated in proximity to the ceramide trihexoside standard on TLC plates. Densitometric scanning of the antigen bands indicated that the tumorigenic rat esophageal cell lines possessed 50%–90% more mAb-5G-reactive antigen than the nontumorigenic esophageal cell lines. The results show that mAb 5G reacts specifically with a glycolipid antigen expressed by tumorigenic and certain non-tumorigenic, immortalized rat esophageal epithelial cell lines that might be at the late stages of transformation and early malignancy.     

Nuclear matrix proteins in well and poorly differentiated human breast cancer cell lines

The nuclear matrix, besides providing the structural support of the nucleus, is involved in various cellular functions of the nucleus. Nuclear matrix proteins (NMPs), which are both tissue- and cell type–specific, are altered with transformation and state of differentiation. Furthermore, NMPs have been identified as informative markers of disease states. Here, the NMP profiles from human breast cancer cell lines and breast tumours were analyzed using two-dimension gel electrophoresis. We identified NMPs that are associated with well and poorly differentiated human breast cancer cells in vitro and in vivo. Five NMPs (NMBC 1–5) were found to be exclusive for well-differentiated human breast cancer cells, while one NMP (NMBC-6) was found to be present only in poorly differentiated human breast cancer cells. The identification of these proteins suggests the potential use of nuclear matrix proteins as prognostic indicators. J. Cell. Biochem. 66:9–15, 1997. © 1997 Wiley-Liss, Inc.     

Immunoassay-based proteome profiling of 24 pancreatic cancer cell lines

Pancreatic ductal adenocarcinoma is one of the most deadly forms of cancers, with a mortality that is almost identical to incidence. The inability to predict, detect or diagnose the disease early and its resistance to all current treatment modalities but surgery are the prime challenges to changing the devastating prognosis. Also, relatively little is known about pancreatic carcinogenesis. In order to better understand relevant aspects of pathophysiology, differentiation, and transformation, we analysed the cellular proteomes of 24 pancreatic cancer cell lines and two controls using an antibody microarray that targets 741 cancer-related proteins. In this analysis, 72 distinct disease marker proteins were identified that had not been described before. Additionally, categorizing cancer cells in accordance to their original location (primary tumour, liver metastases, or ascites) was made possible. A comparison of the cells' degree of differentiation (well, moderately, or poorly differentiated) resulted in unique marker sets of high relevance. Last, 187 proteins were differentially expressed in primary versus metastatic cancer cells, of which the majority is functionally related to cellular movement.     

The novel EpCAM-targeting monoclonal antibody 3–17I linked to saporin is highly cytotoxic after photochemical internalization in breast,pancreas and colon cancer cell lines

The epithelial cell adhesion molecule (EpCAM) is expressed by a wide range of human carcinomas, making it an attractive diagnostic and therapeutic target in oncology. Its recent identification on cancer stem cells has raised further interest in its use for tumor targeting and therapy. Here, we present the characterization and therapeutic potential of 3–17I, a novel human EpCAM-targeting monoclonal antibody. Strong reaction of 3–17I was observed in all lung, colon, and breast human tumor biopsies evaluated. By flow cytometry and confocal fluorescence microscopy, we demonstrate that 3–17I specifically targets EpCAM-positive cell lines. We also show evidence for mAb-sequestration in endo-/lysosomes, suggesting internalization of 3–17I by receptor-mediated endocytosis. The ribosomal-inactivating toxin saporin was linked to 3–17I, creating the per se non-toxic immunotoxin 3–17I-saporin, a promising candidate for the drug delivery technology photochemical internalization (PCI). PCI is based on a light-controlled destruction of endolysosomal membranes and subsequent cytosolic release of the sequestered payload upon light exposure. EpCAM-positive human cancer cell lines MCF7 (breast), BxPC-3 (pancreas), WiDr (colon), and the EpCAM-negative COLO320DM (colon), were treated with 3–17I-saporin in combination with the clinically relevant photosensitizer TPCS2a (Amphinex), followed by exposure to light. No cytotoxicity was observed after treatment with 3–17I-saporin without light exposure. However, cell viability, proliferation and colony-forming capacity was strongly reduced in a light-dependent manner after PCI of 3–17I. Our results show that 3–17I is an excellent candidate for diagnosis of EpCAM-positive tumors and for development of clinically relevant antibody-drug conjugates, using PCI for the treatment of localized tumors.     

Production of human-human hybridomas secreting monoclonal antibodies reactive to breast cancer cell lines

Summary We produced human-human hybridomas by fusing lymph node lymphocytes of breast cancer patients with a fusion partner, HO-323 cells, in the presence of 50% polyethylene glycol, and screened hybridomas producing monoclonal antibodiy (MoAb) reactive to a breast cancer cell line, MCF-7. Among 11 hybridomas secreting IgM reactive to MCF-7, four hybridomas (H15A3, H15F2, K15B4, and K15C3) produced IgM reacting specifically to breast cancer cell lines (MCF-7 and HBC-5). Among them, H15A3 proliferated in a serum-free (RDF) medium supplemented with insulin, transferrin, ethanolamine, selenium, and endothelial cell growth supplement, as fast as in 10% FCS-RDF medium. According to transfer blotting analysis, the H15F2 MoAb reacted with a 40 000 dalton antigen in MCF-7 cells. Editor's Statement Human monoclonal antibodies obviously hold great potential in diagnosis and treatment of disease. Although the antibodies described in this report are not entirely specific for breast cancer cells, the reactivity profile and ease of production as described here may make them a highly useful tool in both basic and applied biomedical research.     

Synergistic anticancer action of quercetin and curcumin against triple-negative breast cancer cell lines

Women with the breast cancer type 1 susceptibility protein (BRCA1) mutation and loss of BRCA1 expression are reported to have an increased risk of triple-negative breast cancer (TNBC). Targeting BRCA1 modulation might offer a therapeutic option to treat TNBC patients. Our studies detected that BRCA1 is poorly expressed in TNBC cell lines and highly expressed in ER⁺ breast cancer cell lines. To modulate BRCA1 expression, we tested two different dietary components to find out if any would induce tumor suppressor genes. We detected that quercetin and curcumin dose-dependently enhanced the BRCA1 expression. Further, a synergistic action of quercetin and curcumin was observed in modulating the BRCA1 level and in inhibiting the cell survival and migration of TNBC cell lines. Quercetin and curcumin appeared to induce BRCA1 promoter histone acetylation. Furthermore, BRCA1 knockdown induced cell survival and cell migration in ER ⁺ cells were significantly decreased by the combined treatment of quercetin and curcumin. Our present study concluded that the combination treatment of quercetin and curcumin acts synergistically to induce anticancer activity against TNBC cells by modulating tumor suppressor genes.     

Viral validation strategy for recombinant products derived from established animal cell lines

For products derived from continuous cell lines, regulatory agencies worldwide require that the purification process be validated for its ability to remove or inactivate potential contaminants such as viruses and virus-like particles. New guidance suggests a requirement for statistical evaluation of these studies but the industry has yet to develop such standards. The task of estimating excess capacity is also complicated by variable assays, accumulation of variability in clearance estimates over unit operations, dependence of clearance capacity on operating parameters, and expense of experiments. We propose an experimental strategy to determine the excess clearance capacity of a biopharmaceutical process and to provide statistical estimation of excess capacity in an efficient way. Clearance estimates and their variances are calculated for each orthogonal unit operation and estimates are combined to form an interval estimate of overall process clearance capacity. Poisson regression is suggested as an efficient technique for data analysis of clearance studies. We believe that this approach should meet regulatory guidelines in a cost effective way, while clarifying the roles of qualitative and quantitative components in setting requirements.     

Paclitaxel administration and its effects on clinically relevant human cancer and non cancer cell lines

Comparisons of the effects of clinically relevant concentrations of the anticancer agent paclitaxel on growth, viability, and apoptosis were determined using in vitro human cell cultures. Growth of the cervical cancer cell line, HeLa-S3, was significantly reduced, and apoptotic index was significantly increased, after 24 h in cultures treated with 12 nM paclitaxel. In contrast, hepatic carcinoma (HEpG2) cells capable of detoxifying paclitaxel were only affected at paclitaxel concentrations ge120 nM. The previously uncharacterized non-cancerous human microvessel endothelial cell line HMEC-1, was more sensitive to paclitaxel treatment than both HeLa-S3 and HEpG2 cells, demonstrating decreased growth and increased apoptosis with 1.2 nM paclitaxel. These results are significant in the design of in vitro cell culture systems to study drug metabolism and toxicity.