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PubMed2000

[Somatostatin receptor subtype 2 mRNA expression in human gastric immortalized cell line and tumor cell lines].

OBJECTIVE: Inhibition of somatostatin on cell proliferation via somatostatin receptor subtype 2 (SS-R2), suggested this receptor subtype may be involved in tumor growth. Present study is to demonstrate whether SS-R2 was expressed in tumor cell lines extensively as well as in human gastric epithelia immortalized cell line. Meanwhile, the effect of p53 mutation on SS-R2 expression in gastric cancer cell line was also elucidated. METHODS: Full-length human somatostatin receptor subtype 2 cDNA was cloned by RT-PCR. Using cDNA as the probe and RT-PCR, expression of mRNA for SS-R2 in 9 cancer cell lines and human gastric immortalized cell line was detected. RESULTS: Data revealed that most cancer cell lines but a pancreatic cancer cell line expressed SS-R2 mRNA. CONCLUSION: Regardless whether p53 mutation or not in human gastric cancer cell lines, SS-R2 mRNA was transcribed.

Cell Line↗

PubMed1996

Immortalized and tumorigenic adult human prostatic epithelial cell lines: characteristics and applications. Part I. Cell markers and immortalized nontumorigenic cell lines.

Several immortalized and malignant adult human prostatic epithelial cell lines have recently been developed. The three most widely used carcinoma cell lines, DU-145, PC-3, and LNCaP, developed between 1977 and 1980, have greatly contributed to our present understanding of prostate cancer. Before a cell line can be accepted as having prostatic epithelial origin, some basic characteristics must be established. Expression of specific cytokeratins, but absence of desmin and factor VIII, should be first determined to establish epithelial origin. Responsiveness to androgens and expression of androgen receptor and prostate specific antigen should be examined under stringent culture conditions to establish prostatic epithelial origin. Response to growth factors and expression of their receptors facilitates further characterization of cell behavior. Cell lines immortalized by human papillomaviruses (HPVs) are of special interest because HPVs are involved in a variety of anogenital cancers and may also play a role in prostate carcinogenesis. Malignant transformation of HPV-18 immortalized cells with the ras oncogene provides cell systems for investigating the multistep process of carcinogenesis. Each cell line has some unique characteristics, whether it arose directly from a carcinoma or resulted from immortalization with simian virus 40 (SV40) or HPV or was transformed in vitro by oncogenes. Comparisons of these characteristics should facilitate elucidation of the mechanisms involved in initiation, promotion, and progression of prostate cancer. These cell lines will further serve as useful models for investigating tumor progression, invasion, metastasis, new therapeutic strategies, drug resistance, and its reversal and chemoprevention. This review will be published in three parts and will summarize cell markers necessary for characterization, as well as the characteristics and some applications of the immortalized as well as malignant adult human prostatic epithelial cell lines. Part 1 deals with cell markers and the immortalized, nontumorigenic cell lines.

Adenoviruses, Human↗

PubMed1981

Sister chromatid exchange in lymphoma line and lymphoblastoid cell lines before and after heterotransplantation into nude mice.

The sister chromatid exchange (SCE) rates of cell lines derived from patients with different malignant and premalignant disease were studied before and after intracerebral inoculation into nude mice and were compared to the SCE frequencies of cell lines from healthy controls. Lymphoma lines characterized by chromosomal markers as well as chromosomally normal lymphoblastoid cell lines were used. The SCE frequencies of nude mouse tumor-derived cell lines did not show a homogeneous pattern. They were either as high as, or higher or lower than, the SCE levels of the original cell line. But all cell lines, karyotypically abnormal as well as normal, originating from patients with malignant and premalignant diseases, showed significantly higher SCE rates than the control lines from healthy donors.

Adult↗

PubMed1985

Inhibition of growth of certain human tumour cell lines by a factor derived from human fibroblast-like cell lines. I. Demonstration by mixed culture and by use of cell washings.

The growth of 7/9 Burkitt's lymphoma (BL) cell lines and 5/6 human melanoma cell lines was inhibited by certain human fibroblast-like cell lines, especially human myofibroblast cell lines. In contrast to BL lines, 3/5 lymphoblastoid cell lines were less susceptible and 3/4 human leukaemic lines were resistant. The effect was time- and concentration-dependent. Co-cultivation led to inhibition of tumour-cell growth within 3 days, but after removal from the fibroblasts, washing, and resuspending in fresh medium some tumour cells recovered and growth improved. The inhibitory activity was also demonstrated with washings of fibroblast-like cell lines, and was sensitive to pronase. The biological significance of this factor remains to be defined.

Autoradiography↗

PubMed2003

Contrasting effects of hydroxyurea on cell growth and reduction in Epstein-Barr virus genomes in EBV-infected epithelioid cell lines vs Burkitt's lymphoma cell lines.

Eliminating Epstein-Barr virus (EBV) genomes from infected cells is an intriguing theoretical strategy in therapy for EBV-associated malignant diseases. Respective patterns were characterized for hydroxyurea (HU)-promoted loss of EBV genomes from EBV-infected epithelioid cell lines derived from the noncancerous portion of gastric carcinoma tissues and Burkitt's lymphoma (BL) cell lines. Epithelioid cell lines GT38 and PN were less sensitivity to HU than BL cell lines Akata, Raji, and Daudi in terms of cell growth inhibition and cell cycle arrest. On passage in medium with 50 microM HU, the fraction of EBV nuclear antigen (EBNA)-positive cells was reduced substantially in the BL cell lines, but only slightly in the epithelioid cell lines. EBV DNA was reduced in Akata, Raji, and Daudi cells upon passage in 50 microM HU by 95%, 70%, and 50%, respectively, but by only 10% in GT38 cells, in which EBV DNA reduction was enhanced at increased concentrations of HU. This indicates that EBV genome is more easily lost from BL cell lines than from epithelioid cell lines upon culturing in HU. These findings support the view that the elimination of EBV could be therapeutically effective in EBV-associated BL by HU.

Burkitt Lymphoma↗

PubMed1988

Comparison of cellular basis of drug sensitivity of human colon, pancreatic, and renal carcinoma cell lines with that of leukemia cell lines.

In an attempt to find how much the low therapeutic effectiveness of antitumor drugs against so-called chemotherapy-refractory tumors such as colon carcinoma depends on drug sensitivity at the cellular level, sensitivity of five carcinoma cell lines (three colorectal, one pancreatic, and one renal) to nine typical anticancer agents was compared in vitro with that of four generally chemotherapy-susceptible leukemia cell lines. Sensitivity was assessed in terms of the percentage cell growth in control cultures, which was determined by exposing exponentially growing cells for 48 h to the following antitumor drugs: 1-(4-amino-2-methylpyridine-5-yl)-methyl-3-(2-chloroethyl)3-nitrosourea hydrochloride (ACNU), adriamycin (ADM), bleomycin (BLM), cisplatin (DDP), etoposide (VP-16), 5-fluorouracil (5FU), mitomycin C (MMC), methotrexate (MTX), and vinblastine (VLB). As expected, 10-fold or greater differences in sensitivity were scarcely ever observed between the two kinds of cell lines. Thus, we recorded a result of more (or less) sensitivity when there was a difference of 3-fold or more; and compared the drug sensitivity in every pair of carcinoma and leukemia cell lines (20 pairs for each drug). We found that carcinoma cell lines were less sensitive to VP-16, ADM, DDP, and MTX than leukemia cell lines in 18, 15, 12, and 10 of 20 pairs, respectively; only one opposite case was observed, with DDP. On the other hand, no such tendency between the two groups was observed with BLM, 5FU, or MMC. Overall, significantly different sensitivities were observed between them in 91 out of 180 pairs (i.e., 9 antitumor drugs x 5 carcinomas x 4 leukemias), and carcinoma cell lines were less sensitive than leukemia cell lines in 79 of these 91 pairs. These results suggest that the refractoriness of colon carcinoma, etc. to chemotherapy is, at least in part, due to low drug sensitivity of the tumor cell itself.

Adenocarcinoma↗

PubMed1979

Sister chromatid exchange in cell lines from malignant lymphomas (lymphoma lines).

The frequency of sister chromatid exchanges (SCEs) was studied in cells from three freshly established lymphoma lines, derived from two patients with Hodgkin's disease and one patient with non-Hodgkin lymphoma. These values were compared to SCE rates found in cells from two long-established lymphoma lines (Raji and BJAB) and to those recorded in control cell lines of normal human donors. The highest SCE levels were demonstrated in the freshly established lymphoma lines, the lowest SCE values separated the lymphoblastoid cell lines from healthy controls, and the older lymphoma lines Raji and BJAB presented rates in between. The influences of BUDR concentration and of the duration of BUDR treatment on the frequency of SCEs were tested. Furthermore, the dependence of the SCE rate on the time interval between establishment of the cell line and its SCE investigation was considered. The connection between elevated SCE rates and the neoplastic nature of lymphoma lines is discussed.

Animals↗

PubMed1992

Radiation sensitivities in various anticancer-drug-resistant human lung cancer cell lines and mechanism of radiation cross-resistance in a cisplatin-resistant cell line.

To determine whether there exists cross-resistance between anticancer drugs and radiation, six drug-resistant human lung cancer cell lines and their parental cell lines were examined for radiosensitivity using a growth-inhibition assay. Only one cisplatin-resistant cell line, PC-9/CDDP, showed cross-resistance to radiation. The other three cisplatin-resistant cell lines (PC-7/CDDP, PC-4/CDDP, and H69/CDDP), an etoposide-resistant cell line (H69/VP) and a camptothecin-resistant cell line (PC-7/CPT) did not show cross-resistance to radiation. To analyze the mechanism of radiation resistance in PC-9/CDDP cells, the formation and repair of radiation-induced DNA single-strand breaks (ssb) and double-strand breaks (dsb) were examined by alkaline elution and neutral elution respectively. Although the formation of DNA ssb and repair of both DNA ssb and DNA dsb were the same for both cell lines, the formation of DNA dsb in PC-9/CDDP cells was significantly less than those in PC-9 cells. Measurement of intracellular glutathione content in all of the cell lines revealed that only PC-9/CDDP cells had a significant increase of glutathione content compared to the parental cells. Buthionine sulfoximine treatment of PC-9/CDDP cells caused an increase of DNA dsb to the same levels as in PC-9 cells after irradiation and caused a complete radiosensitization. These results indicate that cross-resistance to radiation in drug-resistant cells in a rare phenomenon, and increased glutathione content may play a crucial role in the emergence of cross-resistance to radiation in the drug-resistant cells.

Antineoplastic Agents↗

PubMed1987

Differential expression of the HLA-DR genes in various melanoma cell lines treated with interferon-gamma: methylation of the HLA-DR alpha gene in these lines is not correlated with its expression.

Melanoma cell lines treated with or without interferon-gamma were tested for the presence of DR alpha mRNA and protein. The six lines examined fell into three general categories: two that expressed high levels of DR alpha mRNA and protein before and after interferon-gamma treatment, one that expressed very low levels before treatment with interferon-gamma, but was induced to express high levels after interferon-gamma treatment, and three that expressed very low levels before treatment, and were only slightly inducible after treatment with interferon-gamma. The presence of DR-alpha protein on the melanoma cell surface was always positively correlated with the presence of DR alpha mRNA in the cells. Furthermore, in the cell line that was interferon-gamma-inducible, the time at which DR alpha mRNA and protein appeared and the doses of interferon-gamma needed to induce this appearance were directly correlated. Methylation patterns of the DR alpha gene in these cell lines were also studied in order to determine whether the degree of DR alpha gene methylation among the lines correlated with expression of the gene. Digestion of DNA with the restriction enzyme MspI, which recognizes the sequence 5'CCGG3' and 5'CmCGG3', led to the appearance of a 3.1 kb band from all lines tested. Hpa II digestion, which recognizes 5'CCGG3', but not 5'CmCGG3', led to the appearance of 3.1, 4.4, and 6.7 kb bands in all lines tested except for DUMEL 8, which showed only the 3.1 kb band. Interestingly, DUMEL 8 expressed very low levels of DR alpha mRNA and protein before and after interferon-gamma treatment. We conclude that interferon-gamma has a regulatory effect on DR alpha genes of various melanoma cell lines to varying degrees. This may reflect an effect of interferon-gamma on certain subpopulations of melanocytes in vivo. Our data also indicate that partial methylation of the DR alpha gene does not inhibit its expression. Furthermore, interferon-gamma does not appear to induce expression of the DR gene by altering methylation patterns within the region recognized by our probe.

Cell Line↗

PubMed1997

Cell lines with extended in vitro growth potential from human renal proximal tubule: characterization, response to inducers, and comparison with established cell lines.

Few model systems exist for the study of injury to human renal proximal tubule epithelium. Optimized differentiated human renal epithelial cell lines with extended in vitro growth potential would provide an alternative model system to primary culture or other available non-human mammalian kidney cell lines. For this purpose, human renal tubule epithelial cells were isolated from normal kidney cortex and exposed in culture to a hybrid immortalizing virus, adenovirus 12-SV40. Cell lines were developed by limiting dilution, and three selected cell lines were screened for growth pattern, production of immortalizing virus, tumorigenicity, and ploidy. Cell lines were also monitored for response to inducer agents and matrix factors and were screened for expression of biochemical properties and differentiation markers of renal epithelium. All three are nonproducers of the immortalizing virus and are nontumorigenic. They grow in monolayer, have intermediate growth kinetics, and express markers of renal proximal tubular epithelium by immunohistochemistry. They also express biochemical properties comparable to other widely used proximal tubular cell lines including LLC-RK1, OK, and HK-2 and comparable to human tubular cells in stable culture. Growth medium containing low levels of fetal calf serum, or epidermal growth factor combined with parathyroid hormone, produced optimal growth characteristics, brush border enzyme expression, biochemical properties, and glucose transport in a selected cell line. The addition of dimethyl sulfoxide allows maintenance in morphologically intact monolayers for prolonged periods. These cell lines should be useful model systems for the study of human renal proximal tubular injury or disease.

Adenosine Triphosphate↗

PubMed1981

Do cell lines in vitro reflect the properties of the tumours of origin? A study of lines derived from human melanoma xenografts.

The characteristics of 7 human melanoma cell lines were compared with those of the xenografts from which they were established. The ultrastructure, melanin content, isozyme pattern and chromosome numbers of the cell lines were closely similar to those of the corresponding xenografts. The different cell lines gave rise to colonies in soft agar of size and morphology similar to the parent xenografts, and the plating efficiencies were clearly correlated. However, no correlation was found between the growth rates in vivo and either the doubling times and saturation densities in monolayer cultures or the plating efficiencies in soft agar. Moreover, one of the cell lines lost its tumorigenic ability upon establishment in culture. Thus, although the properties of the cell lines by and large reflected those of the parent xenografts, important inconsistencies were seen. The data emphasize that extrapolations from continuous cell lines in vitro to tumour cells in vivo are not necessarily valid. A high content of cellular fibronectin was correlated with a compact colony morphology in soft agar and rapid attachment and spreading on plastic. The growth rates and cellular morphology of the cell lines were strongly influenced by TPA, DMSO, retinoic acid and theophylline, but not by alpha-melanocyte-stimulating hormone. A murine cell line established from one of the xenografts grew in soft agar and produced sarcoma in mice. The malignant murine cells had arisen by transformation of murine stromal cells during the first subcultures in vitro, possibly caused by a factor produced by the human melanoma cells.

Animals↗

PubMed1988

Near neighbour analysis of variant cell lines derived from the promyeloid cell line HL60.

The human promyeloid cell line H60 can be induced to differentiate towards either neutrophils or monocytes. Variant cell lines, derived from HL60, which show reduced capacities for neutrophil and monocyte differentiation can be arranged in a developmental sequence which suggests that the potentials for neutrophil and monocyte differentiation are expressed sequentially by HL60 cells in this order. Analysis of the patterns of total cellular phosphoproteins within HL60 and 5 variant cell lines, by two-dimensional gel electrophoresis, has identified 6 distinct phosphoproteins which show progressive differences in the intensity of spots between the variant lines. The changes in these phosphoproteins relate to the position of the lines within the proposed development sequence. Similarly, lines placed close together in the sequence are more similar, as regards phosphoprotein profiles, than lines placed far apart. These studies provide direct evidence in favour of the hypothesis that the potentials for neutrophil and monocyte differentiation are expressed sequentially during myelopoiesis. Furthermore, two phosphoprotein spots were found to be restricted to lines able to differentiate towards monocytes. These proteins may play important roles during commitment to monocyte differentiation.

Bone Marrow Cells↗

PubMed1994

Radiation response of mouse lymphoid and myeloid cell lines. Part II. Apoptotic death is shown by all lines examined.

The mode of death induced by gamma-irradiation in a panel of 10 mouse lymphoid or myeloid cell lines was examined. Four of these lines were known to lose viability (membrane integrity) rapidly after irradiation, whilst the others were known to lose viability considerably more slowly. However, based on the criteria of morphology and DNA degradation pattern, all 10 lines showed apoptotic death. The occurrence of apoptosis after irradiation in rapid-dying lymphoid cell lines was consistent with published results, whilst the demonstration of apoptosis in slow-dying lines was unexpected. Cells of the slow-dying lymphoid lines underwent one or more mitoses prior to death, a feature also reported for fibroblastoid cell lines. However, the occurrence of radiation-induced necrosis in fibroblasts suggests that the pathways leading to 'mitotic death' differ between fibroblastoid and lymphoid cell lines.

Animals↗

PubMed1991

Cytogenetic responses of human uroepithelial cell lines and a malignant bladder carcinoma cell line to X-rays.

The responses to X-rays of three simian virus 40 (SV40) immortalized but non-tumourigenic human bladder epithelial cell lines have been compared with a malignant bladder epithelial line using the micronucleus assay. A linear increase in induced micronuclei (MN) was observed for all four cell lines with increasing X-ray dose. The three SV40 immortalized lines were found to be significantly less sensitive than the malignant cell line. Spontaneous levels of MN indicate that certain cell lines within the SV40 immortalized lines have a higher genetic instability. These cell lines may have a predisposition towards the generation of a fully transformed phenotype when treated with carcinogenic agents.

Cell Line, Transformed↗

PubMed1984

Constitutive production of phagocytosis inducing factor(s) in a monocyte/macrophage lineage cell line (THP-1) by retrovirus-transformed human T cell lines.

Four human T cell lines, MT-2, TCL-Kan, TCL-As 2, and TCL-Haz, established from normal leukocytes by cocultivation with adult T-cell leukemia (ATL) virus (ATLV)-producing cells, produced constitutively phagocytosis inducing factor(s) (PIF) that induced phagocytosis in a human monocytic cell line, THP-1. These cell lines expressed ATLV-associated antigens (ATLA) as well as numerous virus particles, whereas the other twelve leukocyte cell lines tested, including T cell lines, B cell lines, and non-T and non-B cell lines, did not produce detectable amounts of the factor(s) in the culture supernatants. PIF was produced in the absence of serum and was not related to either ATLV-particles or viral structural proteins. Its activity was stable at 56 C for 30 min, but labile at 80 C for 30 min and at pH 2 for 20 hr. MT-2 and TCL-Kan produced large amounts of the factor(s) in the culture supernatants but little interferon-gamma (IFN-gamma) or colony stimulating factor (CSF) activity was detected; furthermore, the activity was not neutralized by rabbit anti-IFN-gamma sera. These observations suggest that some ATLV-transformed T cell lines produce PIF that is different from IFN-gamma and CSF.

Cell Line↗

PubMed2003

Establishment of conditionally immortalized rat retinal pericyte cell lines (TR-rPCT) and their application in a co-culture system using retinal capillary endothelial cell line (TR-iBRB2).

The purpose of this study was to establish and characterize a retinal pericyte cell line from retinal capillaries of transgenic rats harboring the temperature-sensitive simian virus 40 large T-antigen gene (tsA58 Tg rat), and to apply this to the co-culture with a retinal capillary endothelial cell line. The conditionally immortalized rat retinal pericyte cell lines (TR-rPCTs), which express a temperature-sensitive large T-antigen, were obtained from two tsA58 Tg rats. These cell lines had a multicellular nodule morphology and reacted positively with von Kossa staining, a marker of calcification. TR-rPCTs cells expressed mRNA of pericyte markers such as rat intercellular adhesion molecule-1, platelet-derived growth factor-receptor beta, angiopoietin-1, and osteopontin. Western blot analysis indicated that alpha-smooth muscle actin (alpha-SMA) was expressed in TR-rPCT3 and 4 cells. In contrast, alpha-SMA was induced by transforming growth factor-beta1 and its enhancement was reduced by basic fibroblast growth factor in TR-rPCT1 and 2 cells. When TR-rPCT1 cells were cultured with a rat retinal endothelial cell line (TR-iBRB2) in a contact co-culture system, the number of TR-iBRB2 cells were significantly reduced in comparison with that of a single culture of TR-iBRB2 cells, suggesting that physical contact between pericytes and retinal endothelial cells is important for the growth of retinal endothelial cells. In conclusion, conditionally immortalized retinal pericyte cell lines were established from tsA58 Tg rats. These cell lines exhibited the properties of retinal pericytes and can be applied in co-culture systems with a retinal capillary endothelial cell line.

Actins↗

PubMed1989

Structural analysis of proviruses in additional hamster tumour cell lines transformed by provirus II rescued from XC cells and definition of a new cell line harbouring amplified proviruses.

Additional 18 Syrian hamster tumour cell lines induced independently with the virus rescued from XC cells (provirus type II) have been analysed by restriction mapping. Taking into account the already published results of an analysis of other six tumour cell lines, altogether 24 tumour cell lines were characterized. In 62.5% of these lines a complete proviral unit has been integrated; 20.8% of the lines harbour altered proviral structures where the 3' end of the gag gene and the entire pol gene had been deleted; 8.3% of the lines carry both such a deleted provirus and a complete provirus. Apart from the already published cryptic provirus found in H-19 cells, no such provirus has been found in another cell line. Therefore the appearance of the cryptic provirus represents an infrequent event (4.16%). Similarly, the significant amplification of proviruses accompanied with a rearrangement in the env gene was found only in one tumour cell line. H-42, in the genome of which five proviral units are accommodated. The probable arrangement of amplified proviruses and the mechanism of their genesis are discussed.

Animals↗

PubMed1984

Pathogenesis of tumor desmoplasia. II. Collagens synthesized by line 1 and line 10 guinea pig carcinoma cells and by syngeneic fibroblasts in vitro.

For the investigation of the pathogenesis of desmoplasia, the capacities to synthesize collagen in vitro of 2 bile duct carcinomas (lines 1 and 10) of Sewall-Wright inbred strain 2 guinea pigs and of syngeneic dermal fibroblasts were studied. Line 10 cells synthesized collagen type IV as judged by sensitivity to bacterial collagenase, by immunoprecipitation, by migration of pro alpha (IV) chains and pepsin-resistant fragments on sodium dodecyl sulfate-polyacrylamide gels, and by immunofluorescence. Line 1 cells also synthesized small amounts of collagenase-sensitive protein. Neither line 1 nor line 10 cells synthesized detectable collagen type I, III, or V. Only about 1% of [14C]proline incorporated by tumor cells was found in collagenase-sensitive protein. In contrast, dermal fibroblasts synthesized 4 and 128 times as much collagenase-sensitive protein as line 10 and line 1 cells, respectively, amounting to 20% of total protein synthesized. Fibroblasts produced mostly collagen types I and III, in a ratio of 7:1, and smaller amounts of collagen type V. Thus lines 1 and 10 carcinoma cells produce primarily basement membrane collagen, whereas interstitial collagens, abundant in desmoplastic tumor stroma, are fibroblast products.

Animals↗