Human lung tumour cell line adapted to grow in serum-free medium secretes angiogenesis factor

Characteristics of two cell lines derived from a histologically undifferentiated bronchial carcinoma expressing neuroendocrine markers

This study investigates the characteristics of two human cell lines--1PT and 1PT VARIANT A--both derived from the same histologically undifferentiated, neuroendocrine positive, non-small cell lung carcinoma (NSCLC) and capable of growth in unsupplemented serum-free minimum essential medium. In stationary culture, the cells of both lines grew both attached to a plastic substratum and in suspension; the 1PT VARIANT A line formed three-dimensional clusters of loosely adherent cells. The cell lines differed in their DNA content, the 1PT having 1.44 times and the 1PT VARIANT A having 2.39 times the normal human diploid DNA content. Chromosome counts supported this observation, the ploidy of the 1PT and VARIANT A lines being 1.11 and 1.64, respectively. On transmission electron microscopy the cells of both lines had dense core granules and immature desmosomes, whereas only the 1PT VARIANT A line had mucin granules. Both lines formed, in nude mice, tumors that, like the original tumor from which they were derived, were histologically undifferentiated and showed local invasion. The original tumor and both lines had demonstrable neuroendocrine markers. Cytokeratins were apparent in the tumor but not the cell lines, and neurofilaments were present in the cell lines only. Staining for epithelial membrane antigen, neural cell adhesion molecule, and desmoplakin differentiated between the two lines. These lines provide a useful model for the investigation of the biology of the neuroendocrine positive subgroup of NSCLC, which is clinically important because of the possible responsiveness of these tumors to chemotherapy.

Production of multiple growth factors by a human non-small cell lung carcinoma cell line

The 1PT cell line, derived from an undifferentiated bronchial carcinoma, produced, in conditioned medium, immunoreactive basic fibroblast growth factor (bFGF), insulin-like growth factors I and II (IGF-I and IGF-II), epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha), and transforming growth factor beta-2 (TGF beta 2) in its latent form, but not platelet-derived growth factor (PDGF), tumour necrosis factor alpha (TNF alpha), or transforming growth factor beta-1 (TGF beta 1). Comparative studies of growth stimulation of human umbilical vein (HUV) endothelial cells indicated that the growth factors detected in 1PT-conditioned medium do not solely account for its proliferative effects on these cells. These results support previous characterization studies [1,2] that suggest the production of a potentially novel tumour-derived endothelial cell growth factor by the 1PT cell line.

Tumor cell heterogeneity and subpopulations with metastatic ability in differentiated adenocarcinoma of the lung. Histologic and cytofluorometric DNA analyses

To investigate tumor cell heterogeneity and subpopulations with metastatic ability in differentiated adenocarcinoma of the lung, the primary and metastatic lesions in 20 cases of differentiated adenocarcinoma were examined by histologic and cytofluorometric DNA analyses. The primary tumor was divided histologically into three compartments: tumor area of type 1, papillary adenocarcinoma with thin stroma; tumor area of type 2, papillary adenocarcinoma with thickened fibrovascular stroma: tumor area of type 3; solid carcinoma with scant gland formation. The nuclear DNA content (NDC) was higher in type 2 than in type 1 tumor in terms of mean NDC and DNA histogram pattern (p less than 0.01). Metastatic tumors in distant organs often resembled the type 2 of primary tumors histologically and also in their DNA histogram patterns, and their mean NDC values were significantly correlated with each other (p less than 0.01). Metastatic tumors in regional lymph nodes had a significantly lower mean NDC than those in distant organs (p less than 0.01). These results suggest that (1) type 2 tumors originate from type 1 tumors by malignant progression and metastasize hematogenously, and (2) hematogenous metastases are composed of tumor subclones different from those of lymphatic metastases.

Characterization of the state of differentiation of six newly established human non-small-cell lung cancer cell lines

Six new non-small-cell lung cancer (NSCLC) cell lines were established directly from human tissue or indirectly via nude mouse xenografts in serum-supplemented media with success rates of 8% and 13%, respectively. They comprised one adenocarcinoma (ADLC-5M2), two squamous cell carcinomas (EPLC-32M1, EPLC-65H), two large cell carcinomas (LCLC-97TM1, LCLC-103H), and one malignant biphasic mesothelioma (MSTO-211H). All cell lines grew adherent to culture vessels with population doubling times (PDT) of 16-40 h, formed colonies in soft agarose with efficiencies of 0.1%-5.1%, and all grew in athymic nude mice. Xenograft histologies appeared as follows: (a) undifferentiated carcinomas with feeble resemblance to the original tumors in the case of adenocarcinomas and squamous cell carcinomas; (b) large cell carcinoma with high resemblance to the original tumor; (c) an undifferentiated tumor with predominance of large epithelial cells and few fibrous cells in the case of mesothelioma. Human chorionic gonadotropin (HCG) was found by radioimmunoassay and high-affinity binding sites for epidermal growth factor (EGF) by radio-receptor assay in 4/4 cell lines. A very low activity of L-DOPA decarboxylase (DDC) was detectable only in the adenocarcinoma cell line. All cell lines overexpressed the c-myc protooncogene, and no gene rearrangement or amplification was observed. Chromosome analysis revealed modal chromosome numbers of 70-73 in ADLC-5M2, EPLC-32M1, EPLC-65H, and MSTO-211H. Cell lines derived from large cell carcinoma had modal values of 65 and 170 and a wider chromosome distribution than all other cell lines. A NSCLC specific chromosomal aberration has been undetectable until now. These cell lines may aid in elucidating the biology of NSCLC and its interrelationship to other lung tumors.

A 72 kD trophoblast glycoprotein defined by a monoclonal antibody

A novel trophoblast cell surface antigen has been defined by a monoclonal antibody 5T4, raised following immunisation with wheat germ agglutinin (WGA) purified glycoproteins from deoxycholate (DOC) solubilised human syncytiotrophoblast plasma membrane (StMPM). The distribution of the antigen was determined by indirect immunoperoxidase staining of sections of normal organ and placental tissues as well as immunofluorescence and radiobinding assays with a wide variety of cell lines representing differing normal and tumour cell types. In frozen sections of normal full term placenta, 5T4 is strongly expressed only by the syncytiotrophoblast, some extravillous cytotrophoblast and the amniotic epithelium. The 5T4 antigen is apparently not expressed by any maternal component of the placenta nor is it detected in adult liver, lung, bronchus, heart, testis, ovary, brain, or muscle. The antigen is apparently expressed by several specialised epithelia. Immunoprecipitation of radiolabelled StMPM indicated that 5T4 molecules are glycoproteins of mol. wt of approximately 72 kD on SDS-PAGE. 5T4 antigen is selectively expressed by diverse tumour cell lines, including those of developmental origin. The molecular characteristics, relatively restricted normal tissue distribution and expression by certain tumour cell types make this antigen worthy of future study for use as a diagnostic marker of malignancy.

Tumor angiogenic activity of gynecologic tumor cell lines on the chorioallantoic membrane

Tumor angiogenic activity (TAA) from tumor angiogenesis factor (TAF), produced by 24 cell lines of various kinds of gynecologic tumors, was assayed onto chorioallantoic membranes (CAMs) of chick embryos. Methylcellulose (1%) pellets containing 1 x 10(7) cells were placed on 8-day-old postfertilized CAMs, and the grade of neovascularization was assayed 3 days after inoculation. Neovascularization occurred prominently in such cell lines, as HTBOA (poorly differentiated ovarian carcinoma), HUOCA-II (poorly differentiated clear cell adenocarcinoma), HWUA (poorly differentiated endometrial adenocarcinoma), and in HKUS (uterine cervical small cell carcinoma); however, neovascularization did not occur in SNK (uterine leiomyosarcoma line). The cell lines which secreted TAF showed high heterotransplantability in the nude mice and produced rapidly growing tumors which were rich in blood vessels. However, the SKN line which did not secret TAF was not transplantable. These results suggested that there was a close relationship among TAA, transplantability, and tumor growth rate.

Angiogenesis and the skin

This communication reviews the circumstances of angiogenesis in the embryo and in the adult. Various biochemical and physical factors reported to influence new blood vessel growth are discussed. Particular emphasis is given to angiogenesis occurring in the skin. Evidence concerning an epidermal stimulus for vascular growth is examined.

Angiogenic factors

Within the past 2 years, several angiogenic factors have been fully purified, their amino acid sequences determined, and their genes cloned. These polypeptides include acidic and basic fibroblast growth factor, angiogenin, and transforming growth factors alpha and beta. Other less well characterized angiogenesis factors have also been isolated, some of which are lipids. This article traces the discovery of the angiogenic factors and describes their possible significance in understanding growth regulation of the vascular system. When evaluated according to their putative targets, they appear to fall into two groups: those that act directly on vascular endothelial cells to stimulate locomotion or mitosis, and those that act indirectly by mobilizing host cells (for example, macrophages) to release endothelial growth factors. In addition to their presence in tumors undergoing neovascularization, the same angiogenic peptides are found in many normal tissues where neovascularization is not occurring. This suggests that physiological expression of angiogenic factors is tightly regulated. In addition to the persistent angiogenesis induced by tumors, it now appears that a variety of nonneoplastic diseases, previously thought to be unrelated, can be considered as "angiogenic diseases" because they are dominated by the pathologic growth of capillary blood vessels.

Therapy of spontaneously metastatic HSV-2 induced hamster tumours with cortisone acetate administered with or without heparin

Subcutaneous injection of cortisone acetate administered with or without oral heparin retarded the growth of two HSV-2 induced hamster fibrosarcomas. Histological sections showed no obvious difference between the vasculature of treated and untreated tumours although there were fewer infiltrating lymphocytes in treated tumours. Treatment was, however, found to be ineffective against metastatic development following resection of primary tumours. Natural killer cell activity was found to be greatly reduced in animals receiving heparin and/or cortisone acetate treatment and this may influence the effectiveness of treatment on the metastatic process. We conclude that treatment of tumours with cortisone plus heparin is no different from the response to cortisone used alone.

Isolation and characterization of angiogenin, an angiogenic protein from human carcinoma cells

The first human tumor derived protein with in vivo angiogenic activity to be obtained in pure form has been isolated from serum-free supernatants of an established human adenocarcinoma cell line (HT-29) and named angiogenin. It was purified by cation-exchange and reversed-phase high-performance liquid chromatography; the yield was approximately 0.5 microgram/L of medium. Biological activity of angiogenin was monitored throughout purification by using the chick embryo chorioallantoic membrane assay. Statistical evaluation demonstrates that it displays activity in this system with as little as 35 fmol per egg. Moreover, only 3.5 pmol is required to induce extensive blood vessel growth in the rabbit cornea. The amino acid composition of this basic (isoelectric point greater than 9.5), single-chain protein of molecular weight approximately 14 400 has been determined. The amino terminus is blocked, and the carboxyl-terminal residue is proline.

A mathematical model of tumour-induced capillary growth

The corneal limbal vessels of an animal host respond to the presence of a source of Tumour Angiogenesis Factor (TAF) implanted in the cornea by the formation of new capillaries which grow towards the source. This neovasculature can be easily seen and studied and this paper describes a mathematical model of some of the important features of the growth. The model includes the diffusion of TAF, the formation of sprouts from pre-existing vessels and models the movement of these sprouts to form new capillaries as a chemotactic response to the presence of TAF. Numerical results are produced for various values of the parameters which characterize the model and it is suggested that the model might form the framework for further theoretical work on related phenomena such as wound healing or to develop strategies for the investigation of anti-angiogenesis.

Tumor-derived angiogenesis factors from rat Walker 256 carcinoma: an experimental investigation and review

Angiogenesis, the process of developing a hemovascular network, is an essential feature of the growth of solid tumors, and is induced by factors secreted by tumor cells. Assay procedures suitable for the investigation of angiogenesis, and for the screening of angiogenesis factors during purification are reviewed; and a number of reports describing the purification of angiogenesis factors, primarily from the rat Walker 256 carcinoma as starting material, are discussed. Work from the authors' laboratory is also presented. Walker 256 cells grown in large-scale culture were the source of a reproducible and homogeneous source of angiogenic material. Factors secreted by these cells were isolated by a series of chromatographic steps. Ion exchange chromatography on carboxymethyl-Sephadex produced two active fractions, one of which was fractionated into several macromolecular species by lectin affinity and hydrophobic adsorption chromatography. The other gave a high mol.wt, active fraction that was resolved into a low mol.wt, active component and a non-angiogenic but possibly carrier molecule with a mol.wt of 140,000. While none of the angiogenic factors were identified chemically, the results demonstrate the existence of both high and low mol.wt tumor-secreted angiogenic substances, confirming the hypothesis for tumor-induced angiogenesis and predicting potential means to interfere with the process of tumor growth.

Tumor angiogenesis

The hypothesis that tumors are angiogenesis dependent has, in the past decade, generated new investigations designed to elucidate the mechanism of angiogenesis itself. Many laboratories are now engaged in this pursuit. Some are studying angiogenesis that occurs in physiological situations, whereas others are interested in angiogenesis that dominates pathological conditions. These efforts have led to (1) the development of bioassays for angiogenesis; (2) the partial purification and, in one case, the complete purification of angiogenic factors from neoplastic and non-neoplastic cells; (3) the development of new polymer technology for the sustained release of these factors and other macromolecules in vivo; (4) the cloning and long-term culture of capillary endothelial cells; (5) the demonstration of the role of nonendothelial cells, such as mast cells in modulating angiogenesis; (6) the discovery of angiogenesis inhibitors; and (7) the demonstration that certain animal tumors will regress when angiogenesis is inhibited. The effects of angiogenesis inhibitors provide perhaps the most compelling evidence for the role of angiogenesis in tumor growth. It is conceivable that the original effort to understand the role of angiogenesis in tumor growth will also lead to the use of angiogenesis inhibitors as a new class of pharmacologic agents in a variety of non-neoplastic diseases such as arthritis, psoriasis, and ocular neovascularization. However, much work remains to be done before it will be possible to understand (1) the regulatory systems that govern capillary density in normal tissues; (2) the factors that maintain the viability of microvascular endothelium; (3) the development of the vascular system itself; and (4) the mechanism by which vascular regression occurs, both in the embryo and in the postnatal organism. A knowledge of the mechanisms which underlie these normal processes may help to enlarge our comprehension of tumor angiogenesis.