Characterization of a newly established, TA-4-producing squamous carcinoma cell line derived from metastatic tongue carcinoma

A human squamous carcinoma cell line was established from the pleural effusion of a patient with recurrent squamous carcinoma of the tongue. The cell line, designated HST-I, has been passaged 82 times over a period of 4 years. The cells have been shown by light and electron microscopy to be of the squamous epithelial type. Immuno-histochemical staining was positive for keratin. When these cells were transplanted into athymic nude mice, tumors developed at the site of inoculation, which on histological examination were shown to be well-differentiated squamous carcinomas. Karyotypic analysis of cells from the cell line demonstrated an aneuploid human type with a modal chromosome number of 71, with both numerical and structural aberrations. HST-1 cells produce and secrete TA-4, a squamous-cell carcinoma-related antigen, in vitro in culture and in vivo in nude mice bearing the tumors produced by inoculation of cultured cells. Thus, the HST-1 cell line represents a new human tongue squamous carcinoma producing TA-4. This cell line appears useful for facilitating therapeutic investigations as well as biological studies on the association between cancerous growth and circulating TA-4 levels.     

Establishment of a novel cell line derived from nasopharyngeal carcinoma

A novel epithelial cell line (designated as HNE-1), derived from nasopharyngeal carcinoma (NPC), was established and has passed more than 100 generations over one year. The NPC biopsy specimen was taken from a 27 year old man with poorly differentiated squamous cell carcinoma of the nasopharynx. The cultured cells showed polygonal shape and grew into multilayers under the inverted microscope. Electron microscopy showed that HNE-1 cells were characterized by bi-directional differentiation with some being poorly differentiated squamous carcinoma and the other poorly differentiated adenocarcinoma cells. A continuous positivity was showed by EBNA at subcultures 5-81. Tumorigenicity was demonstrated by heterotransplantation in BALB/c (nu/nu) mice, developing into well differentiated squamous carcinoma. Karyotype analysis showed aneuploidy with the modal chromosomal number 74-101 (5th-20th passages) and 15 marker chromosomes. The frequency of spontaneous sister chromatid exchange was very high in HNE-1 cells (87.6 +/- 0.4/cell).     

Establishment of a cell line (HCC-M) from a human hepatocellular carcinoma

A continuous human cell line was established from a hepatocellular carcinoma of an HBsAg-positive Japanese male. The cell line, designated HCC-M, grows as an adhering monolayer with a doubling time of 24 h in medium RPMI-1640 supplemented with 10% FCS and grows with 30% clonal efficiency in soft agar. The cells have been shown by light and electron microscopy to be of epithelial type. When they were transplanted subcutaneously into the back of athymic nude mice (BALB/c, nu/nu), tumors developed at the sites of inoculation, which were shown to be hepatocellular carcinoma, similar in morphology to the original tumor from which they were derived. HCC-M had a chromosome mode of 63 with five identifiable marker chromosomes. HCC-M produced albumin at the 10th passage but this property was lost by the 30th passage. This cell line has not secreted alpha-fetoprotein. Hepatitis B viral particles or HBsAg have not been demonstrated in the cells from the primary culture nor in several subsequent subcultures tested.     

ESTABLISHMENT OF A NOVEL CELL LINE (HNE_(1)) DERIVED FROM A NASOPHARYNGEAL CARCINOMA

A novel epithelial cell line, designated HNE1 was established from a biopsy specimen of a naso-pharyngeal carcinoma (NPC). Electron microscopic examination of the HNE1 cells demonstrated bi-directional differentiation, with some cells displaying features of poorly differentiated squamous cell carcinoma, while other cells appeared to have the morphology of poorly differentiated adenocarcinoma. The HNE1 cell line has been passaged more than 100 times over a period of one year. We recently reported that the Epstein-Barr virus (EBV) nuclear antigen (EBNA) was detected in a low pe rcentage of the HNE1 cells examined at subcultures 5-81; the cells were also shown to be EBV DNA positive. Tumorigenicity of the HNE1 cells was demonstrated by xentransplanta tion in athymic nude mice. The developed tumors were characterized as well-differentiated squamous cell carcinomas upon histological examination. Kar yotypic analysis of the HNE1 cells demonstrated an aneuploidy with a modal chromosomal number of 74 at passage     

Establishment and characterization of primary human pancreatic carcinoma in continuous cell culture and in nude mice.

Primary human panceratic exocrine adenocarcinoma has been established in tissue culture and as xenografts in immune-deficient nu/nu mice. The cell line has a doubling time of 36 h and grows as a confluent monolayer together with a constant population of free-floating cells. Evidence of tumourigenicity was provided by growth on an early diploid fibroblast monolayer and in soft agar, and as solid tumours in immune-deficient nu/mu mice. Chromosome analysis of the cultured cells confirmed their tumour origin. Xenografts established from the cell line or directly from primary tumour tissue have retained a similar histology to the original tumour on serial transplantation. An electrophoretic study of exportable pancreatic digestive enzymes and a number of intracellular enzymes has shown that the cell line and xenografts maintain a human intracellular enzyme profile, but do not produce pancreatic digestive enzymes.     

Functional advantage of NPC-related V-val subtype of Epstein-Barr virus nuclear antigen 1 compared with prototype in epithelial cell line

Epstein-Barr virus (EBV) is closely associated with nasopharyngeal carcinoma (NPC) and the viral nuclear antigen 1 (EBNA1) plays a crucial role in viral latency. Three EBNA1 subtypes, P-ala, V-thr and V-val have been detected from healthy carriers in Guangzhou area. A close relation of V-val EBNA1 with NPC was suggested by its preference to infect NPC cells. We therefore investigated the functional difference among these three EBNA1 subtypes in human epithelial cell line. The three coding sequences of the EBNA1 subtypes were cloned into the pGFP-C2 vector, and transfected into 293 cells, respectively. Effect of EBNA1 expression on cell proliferation was examined. The maintenance activity and expression level of EBNA1-plasmid in 293 cells were evaluated by using GFP as a reporter. The expression of P-ala, V-thr or V-val EBNA1 had no effect on 293 cell growth, while the relative average intensity of fluorescence after 14-day selection in V-val-EBNA1/293 cells was statistically higher than P-ala-EBNA1/293 (P<0.05, t test). We suggest that V-val EBNA1 with the functional advantage compared with prototype shown in this study might contribute to the tumorigenesis of NPC by increasing the expression of itself or other viral or cellular genes.     

Characterization of a newly established human Burkitt's lymphoma cell line, OMA-BL-1.

Using culture techniques, we have been able to grow occult tumor cells from the bone marrow from cancer patients and have developed a new malignant lymphoid cell line, OMA-BL-1, from the bone marrow of a 17-year-old patient with recurrent Burkitt's lymphoma. The tumor cells grew rapidly in vitro in suspension culture, and very aggressively in vivo in athymic nude mice with metastases to the liver and abdominal cavity. The morphological, chromosomal, immunophenotypic and molecular biologic characteristics of fresh uncultured tumor cells from the patient and tumor cells grown in culture and in athymic nude mice were very similar. The cells were positive for Epstein-Barr virus-associated nuclear antigens (EBNA) and chromosome analysis of the cells revealed an atypical chromosomal abnormality of 45,X,-X,i(8q), HSR(18)(q21),t(8;14)(q24;q32). Southern analysis demonstrated that c-myc was rearranged and amplified in these cells. Immunophenotypic analysis of the cells using flow cytometry showed monoclonal B cells expressing a surface IgG-kappa isotype. The tumor cells grown in nude mice had a significant decrease in CD24 expression when compared to cultured tumor cells. Electron microscopy of the fresh and cultured cells revealed Herpes virus, most likely Epstein-Barr virus, particles. This cell line has been maintained in culture for over 18 months. The aggressive growth and metastatic properties of this cell line in athymic nude mice make it a potentially useful experimental model to study the biology of human lymphoma.     

Tumour-induced host stromal-cell transformation: induction of mouse spindle-cell fibrosarcoma not mediated by gene transfer

Tumour-induced host-cell transformation has been addressed by examining human tumours in situ and following xenograft to nude mice. We have found evidence for the transformation of host stromal fibroblasts both in vivo and following the introduction of the tumours to in vitro culture. The in vitro culture of one such xenograft--derived from a human prostatic adenocarcinoma--resulted in the outgrowth of a transformed aneuploid mouse cell line. This transformed line was tumourigenic both in BALB/c nu/nu (nude) mice and in heterozygous nu/+mice, with the morphology of a spindle-cell sarcoma. The cell line did not express human isozymes or human histocompatibility antigens, nor were human chromosomes present. Moreover, human DNA sequences were not detected by human Alu repeat sequence element probing in the transformed cell line grown either in vitro or in vivo. The line contained retroviral long terminal repeat sequences but there was no evidence of proviral activation. These findings indicate that tumour cells may cause transformation of neighbouring stromal cells; that this transformation may proceed in the absence of DNA transfer or activation of endogenous proviruses; and that the means of this observed transformation may involve humoral factors elaborated by the tumour cells.     

Oncogenicity of a nude mouse cell line transformed by a human papovavirus

Primary cultures of NIH nude mouse (nu/nu) kidney cells were transformed with a human papovavirus (MMV). The transformed cell line expressed T-antigen, and MMV DNA was found to be associated with the cell DNA. When NIH nu/nu mice were inoculated with the transformed cells, they developed tumors at the injection site but failed to generate detectable levels of T-antibody. A control group of nu/+ littermates rejected the tumor inoculum but mounted an antibody response to T-antigen. It was proposed that nude mouse cells may be a suitable system to test oncogenicity of in vitro transformed cells.     

In-vitro resistance of cloned human glioma cells to natural killer activity of allogeneic peripheral lymphocytes.

Cells from an established culture of a human astrocytoma were incubated with normal allogeneic peripheral lymphocytes (PBL) in order to study the natural killer (NK) sensitivity of the in vitro propagated cell line. A proportion of cells in culture formed halos, into which lymphocytes did not penetrate. These cells were successfully cloned and showed a decreased susceptibility to NK cytolysis compared with the parent line. Both cell lines could be transplanted into athymic nude mice. The cloned NK-resistant cells underwent a frequent spontaneous regression in nu/nu mice, despite the fact that when used as targets for nu/nu NK cells in vitro they were only moderately susceptible. Phase-contrast microscopy of the mass-cultured cells co-cultivated with lymphocytes suggested that their morphology and ability to form inpenetrable translucent halos might influence their susceptibility to NK lysis. Experiments performed on this assumption revealed that quiescent and halo forming tumour cells were not the primary targets for NK lysis. Cells in mass culture, although tumorigenic, were thus heterogeneous in respect of susceptibility to NK attack. These findings might be relevant to the mechanism of immune escape and tumour heterogeneity in respect of spontaneous cell-mediated lysis.     

Heterogeneity of Epstein-Barr virus. IV. Induction of a specific antigen by EBV from two transformed marmoset cell lines in Ramos cells.

Infection of cells of the EBV-genome-negative human B-lymphoma Ramos line with viral isolates obtained from two EBV-transformed marmoset cell lines (B95/8; Nyevu) resulted in the induction of a nuclear antigen (RAM-ag) apparently different from other EBV-associated antigen complexes. This antigen is revealed by indirect immunofluorescence and shows no detectable cross-antigenicity with EBNA or any other known EBV-associated antigen. EBV-isolates from P3HR-1 cells fail to induce a similar antigen in Ramos cells although they induce EBNA. No RAM-ag was expressed, either after infection of cells of another EBV-genome-negative human B-lymphoma line BJAB with B95-8 EBV or in a series of EBV-harbouring cell lines. Thus the antigen appears to be cell-line-specific for Ramos cells. It is also induced upon infection of either B95-8 or P3HR-1 converted Ramos sublines with EBV from B95-8 cells. All human sera with RAM-ag-reactivity revealed antibodies against VCA. However, sera from patients with acute infectious mononucleosis containing high anti-VCA-antibodies did not react with RAM-ag. Seroconversion for this antigen apparently more closely coincides with the appearance of EBNA-directed antibodies.     

Stable transfection of a human lymphoma line by sub-genomic fragments of Epstein-Barr virus DNA to measure humoral and cellular immunity to the corresponding proteins

An Epstein-Barr virus (EBV)-negative human lymphoid B-cell line, DG75, was stably transfected with recombinant selection vectors that carry a subfragment of the BamHI WYH region (nucleotides 44664 to 50628), the BamHI K fragment, or a subfragment of the EcoRI D region (nucleotides 166614 to 170149) of B95-8 EBV DNA. These fragments contain the coding exons for the EBV-determined nuclear antigens EBNA2 and EBNA1, and the membrane antigen LMP, respectively. Antigen expression of the cells was detected by immunofluorescence. EBNA2 was expressed in 80–100% of the transfected cells, in contrast to EBNA1 which was expressed in only 25%, and LMP in only about 5% of the cells. Humoral antibody responses were measured by immunofluorescence and compared to cellular immunity as determined by the leukocyte migration inhibition (LM1) technique. Extracts from transfected cell lines expressing EBNA1, EBNA2 or LMP elicited an LMI response with cells from healthy EBV-seropositive individuals whereas the extract from the parental DG75 cell line did not, The results demonstrate the value of stably transfected cell lines expressing a defined EBV antigen for the monospecific analysis of host responses to the EBV-encoded antigen complex in growth-transformed cells.     

An epithelial cell line with chronic polyoma infection established from a spontaneous mouse pancreatic adenocarcinoma.

The establishment of an epithelial cell line from a mouse pancreatic adenocarcinoma is described. The cell line, designated LTPA, was aneuploid and exhibited many transformed growth properties (rapid growth rate, failure to show density-dependent inhibition of growth, ability to grow in defined medium). A type C oncornavirus was isolated from the culture medium, and electron microscopy also revealed the presence of intracisternal type A particles. LTPA cells carried a persistent polyoma infection which produced only low levels of cytopathic effects. A mycoplasmal contamination was also carried. When injected s.c. into Swiss nu/nu mice, LTPA cells formed ductular structures which were destroyed by inflammatory reactions within 3 weeks.     

Recombinant human granulocyte-colony-stimulating factor (rhg-csf) does not stimulate in-vivo tumor-growth of the human colon-cancer cell-line htb 38 which is responsive in-vitro

Haematopoietic growth factors such as human granulocyte colony-stimulating factor (G-CSF) have been shown to stimulate in vitro growth of some human solid tumour cell lines. Among these is the human colorectal adenocarcinoma cell line HTB 38. The in vivo relevance of this finding was tested by xenografting HTB 38 cells intracutaneously into athymic nu/nu BALB/c mice. Recombinant human (rh) G-CSF was administered as a subcutaneous bolus twice daily from day 1 to 14 after tumour transplantation at a dose level of 312 mug/kg/day. Serum levels of rhG-CSF were within the range required for the in vitro effect. However, the cytokine caused no significant growth modulation of the tumour in vivo.     

Epstein-Barr virus (EBV)-related oral squamous cell carcinoma in Okinawa,a subtropical island,in southern Japan--simultaneously infected with human papillomavirus (HPV)

Up to now, many authors have reported on the EBV infection and its carcinogenic importance in undifferentiated nasopharyngeal carcinoma (WHO classification, type III), but the infection of the virus in well differentiated oral squamous cell carcinoma has not been well described. We introduce the EBV-related well differentiated oral squamous cell carcinomas in Okinawa, a subtropical island in the southernmost part of Japan. This study aimed to clarify the pathogenesis of this malignancy in this area by carrying out analysis of the histology and the Epstein-Barr (EBV) and human papillomavirus (HPV) infection. In the Department of Oral Surgery, Ryukyu University Hospital Okinawa, 188 cases of oral malignant tumours were encountered from 1996 to 2000. The histopathological examination and the sequence analysis of LMP-1 carboxy terminal region and EBNA2 region of EBV were carried out, as were the analysis of virus subtypes, A and B, BamHI-F and f, and C and D. Additionally, HPV infection in the squamous cell carcinomas were demonstrated using E6 and E7 region primer sets by PCR method. In Okinawa, 94% (177/188) of the cases were squamous cell carcinomas. A surprisingly large number of EBV (72%) and HPV (78%) infections in the oral squamous cell carcinomas were demonstrated. EBV type B virus infection was found in 36% of EBV-related oral squamous cell carcinoma in Okinawa, but in only 2-5% of the mainland cases. In both regions the incidence of the BamHI- f variant infection was very low. The infected virus in 79 out of 80 (39 Okinawan and 41 mainland) cases was BamHI- F type. In Okinawa, the numbers of C and D variants were almost equal, whereas in the mainland the D variant was rare. Further, a 30 bp deletion in LMP-1 gene was frequently demonstrated in Okinawan and mainland cases of type A virus, but not in type B virus. Lastly, single nucleotide mutations in EBNA2 region of type A virus when compared with B95-8 strain were demonstrated in Okinawan cases. The prognosis for (mostly EBV/HPV infected) squamous cell carcinomas in Okinawa was better than that in the mainland where most cases were negative for EBV and/or HPV.     

Monoclonal antibody (G10) to a common antigen of human squamous cell carcinoma: binding of the antibody to the H type 2 blood group determinant

The IgM monoclonal antibody G10 was raised against the human squamous cell carcinoma (SCC) cell line UM-SCC-1. In initial screening against cultured cells, G10 bound to 2 SCC lines (UM-SCC-1 and UM-SCC-13) and 1 pancreatic carcinoma line (UM-PAd-1) but not to cultured fibroblasts (WI-38), ovarian carcinoma cells (SK-OV-3), or malignant melanoma cells (SK-MEL-28 and MeWo). In subsequent tests against cultured cell lines, G10 gave positive reactions with 30 of 33 SCC lines but only 4 of 29 non-SCC lines. The non-SCC lines that bound G10 were UM-PAd-1, 2 transitional cell carcinoma lines (T24 and RT4), and 1 melanoma line (SK-MEL-22). When tested against cultures derived from normal skin or mucosa, G10 was reactive with the epitheloid squamous cells but not with the fibroblasts in each culture. The antigen defined by antibody G10 was stable to fixation with Formalin, and its distribution in tissue sections was examined with the use of immunoperoxidase assays. All SCC biopsy specimens examined in this way were reactive with antibody G10. In similar tests against sections of fixed normal tissues, G10 stained the superficial squamous cells of the epidermis and the basal and suprabasal layers of mucosal squamous epithelial cells from the esophagus. All layers of the laryngeal epithelium were positive. Endothelial cells and certain glandular cells were also positive for G10 binding. G10 agglutinated human red blood cells of all blood groups except those from individuals of the Bombay group (Oh) who lack the H blood group determinant. Against defined oligosaccharides, G10 bound strongly only to the monofucosyl H type 2 structure and was slightly cross-reactive with the synthetic difucosyl H type 2 or Y structure. These results are consistent with previous reports of blood group antigen tissue distribution and indicate that the H type 2 determinant is expressed by all or nearly all mucosal squamous cancers. Less frequent expression by cells of other tumor types may correlate with tissue-specific activation of the H gene-specified fucosyltransferase.     

Chemically induced tumors of rat olfactory epithelium: a model for human esthesioneuroepithelioma

N-Nitrosopiperidine (CAS: 100-75-4) and 2,6-dimethylnitrosomorpholine induced tumors of the olfactory epithelium in white Wistar rats. Some tumors were serially transplanted to NMRI nude mice (nu/nu) and passaged up to 16 times in a 1-year period. Tumor tissues from rats and mice were analyzed by conventional pathological stains, by electron microscopy, and by immunofluorescence microscopy with the use of antibodies specific for different intermediate filaments. Both carcinogens induced tumors built of undifferentiated small, round cells in which neuroblastic (Homer-Wright) rosettes and ependymal (Flexner) rosettes were visible. In some tumors areas of squamous cell metaplasia could be observed, which sometimes differentiated toward squamous cell carcinoma. Electron microscopy showed neurosecretory granules in some tumor cells, and biochemical studies of plasma showed in some instances elevated ACTH and calcitonin levels. Intermediate filament typing showed that in general the undifferentiated tumor cells lack intermediate filaments, although in 6 of 29 tumors a few cells that stained positively for neurofilaments were found. Flexner rosettes, the areas showing squamous cell differentiation, and occasional single tumor cells were positive with keratin antibodies. Neurofilament expression was observed in a minor population of tumor cells placed in tissue culture. These findings are used to argue that the chemically induced rat tumors are a model for human esthesioneuroepithelioma and furthermore that the light basal cells of the epithelium may be the stem cells of the rat tumors as well as of its rare counterparts in humans.     

Burkitt-like lymphoma in an English child: characterisation of tumour biopsy cells and of the derived tumour cell line

An eight year old English boy presented with an abdominal undifferentiated 'Burkitt-like' lymphoma. Lymphoma cells from ascitic fluid were cultured on a human embryo fibroblast feeder layer and, after a short lag period, a cell line (DH-BL) was established which, like the original tumour, was both negative for the Epstein-Barr nuclear antigen (EBNA) and expressed a monoclonal pattern of surface immunoglobulin (alpha lambda). DH-BL also possessed the Burkitt-related 8:14 chromosome translocation in all metaphases analysed; no other chromosomal abnormalities were present. The cell surface phenotype of the original biopsy cells and the cultured tumour cells in early passage were investigated using a panel of monoclonal antibodies to B lineage-associated antigens. These antibodies had recently been used to characterise African 'endemic' Burkitt's lymphoma (BL) biopsy cells and their derived cell lines. The cell surface phenotype of this English EBNA negative Burkitt-like lymphoma biopsy was indistinguishable from that previously shown by biopsies of EBNA positive endemic BLs. It therefore appears that both the endemic and sporadic forms of BL, as illustrated by this case, may be derived from the same subset of progenitor cells.     

Sex hormone response of a newly established squamous cell line derived from clinical esophageal carcinoma

Biopsy tissues from a 68-year-old Japanese man with metastases to axillary lymph nodes of a recurrent esophageal carcinoma were adapted to cell culture conditions and a continuously growing tumor cell line was developed. Immunohistochemical staining revealed that these cells contained keratinous material and the electron microscopic study revealed the presence of tonofilaments. Thus, this line, designated the KSE-1 line, was considered to have originated from metastatic squamous cell carcinoma of the esophagus. This line has a binding content of 4.2 fmol/mg protein for the estrogen receptor and 2.2 fmol/mg protein for the testosterone receptor. By measurement of cell number and thymidine incorporation, the growth rate of this line was found to be moderately responsive to these hormones, being inhibited by estrogen and enhanced by testosterone at concentration levels between 10(-13) and 10(-8) and 10(-13) and 10(-6) mg/ml, respectively.     

Soluble CD44 inhibits melanoma tumor growth by blocking cell surface CD44 binding to hyaluronic acid.

Proteolytic cleavage of the extracellular domain of CD44 from the surface of cells has been observed recently in different cell types. In cell culture supernatants of human melanoma cell lines a 70 kDa soluble CD44 protein (solCD44) was detected at concentrations of 250-300 ng/ml. Protease inhibitor studies revealed that serine proteases and metalloproteases are involved in the cleavage of CD44 from the surface of melanoma cells. To analyse a possible function of soluble CD44 a human malignant melanoma cell line was stably transfected with cDNAs encoding either wild type soluble CD44s or mutated forms with defective HA binding properties (CD44sR41A and CD44sR150A/R154A). Soluble CD44s almost completely inhibited hyaluronic acid binding by melanoma cells, whereas soluble CD44 mutated in the HA binding domain had no effect. When cultivated on hyaluronic acid, melanoma cell proliferation was induced by 30% for both the parental and the control transfected cells. This increase in proliferation was blocked completely in solCD44s-secreting transfectants, whereas solCD44sR41A and solCD44sR150A/R154A-secreting cells again showed hyaluronic acid-induced cell proliferation. These cell lines were subcutaneously injected into MF1 nu/nu mice to compare their growth as tumors in vivo. Compared to tumors derived from parental and control transfected cells, we observed a dramatic reduction of primary tumor growth with solCD44s expressing MM cells. Transfectants expressing solCD44s mutated in the HA binding domain in contrast developed fast-growing primary tumors. These results provide strong evidence that direct solCD44 interactions with hyaluronic acid interfere competitively with processes induced by hyaluronic acid binding to surface CD44. Autocrine, or drug-induced secretion of solCD44 by human melanoma cells may thus exert potent antitumoral effects in vivo.