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Biomedical subjects

F Ciardiello

Publications and source records attributed to F Ciardiello.

121 records · Page 7Linked to original sources
PubMed1989

Transformation of an established mouse mammary epithelial cell line following transfection with a human transforming growth factor alpha cDNA.

To determine whether the enhanced expression of transforming growth factor alpha (TGF alpha) is sufficient to induce the neoplastic transformation of an immortalized population of mammary epithelial cells, we cotransfected NOG-8 cells, a cloned mouse mammary epithelial cell line, with a simian virus 40-human TGF alpha cDNA expression vector plasmid and a pSV2neo plasmid. After cotransfection, nine G418-resistant NOG-8 colonies were cloned and expanded. All clones were subsequently analyzed for TGF alpha mRNA expression by northern blot analysis, TGF alpha secretion, anchorage-dependent growth in serum-free medium, anchorage-independent growth in soft agar, and tumorigenicity in nude mice. Three TGF alpha-transfected NOG-8 clones expressed high levels of a specific TGF alpha mRNA, secreted elevated levels of TGF alpha into the culture medium (177-595 ng/10(8) cells/48 h), exhibited an enhanced growth rate, grew aggressively as colonies in soft agar, and formed undifferentiated, invasive carcinomas in nude mice. A neutralizing mouse monoclonal antibody generated against the low molecular weight human TGF alpha peptide was able to inhibit colony formation in soft agar by TGF alpha-transfected NOG-8 clones that produced high levels by TGF alpha. This inhibition suggested that TGF alpha acted through an external autocrine loop. NOG-8 cells and NOG-8 cells transfected with a pSV2neo plasmid alone secreted very low levels of TGF alpha, failed to grow as colonies in soft agar and did not form tumors in nude mice. These results demonstrate that overexpression of a human TGF alpha cDNA in immortalized, nontransformed mouse mammary epithelial cells can induce a transformed phenotype in vitro and can facilitate tumor formation in vivo.

Animals↗
PubMed1989

Transforming growth factors in human breast cancer.

Transforming growth factors alpha and beta (TGF alpha and TGF beta) are two growth factors which are frequently associated with a number of human breast cancer cell lines and with primary human breast carcinomas. Expression of TGF alpha protein and specific TGF alpha mRNA transcripts (4.8 and 1.6 kb) can be induced by estrogens in estrogen-responsive breast cancer cells, suggesting that the mitogenic effects of estrogen may in part be mediated through this potential autocrine growth factor. In contrast, anti-estrogens such as tamoxifen can increase the secreted levels of TGF beta, which is a potent growth-inhibitor for some human breast cancer cell lines. Anti-estrogens generally decrease TGF alpha production. TGF alpha mRNA expression has been detected in approximately 40-70% of primary human breast tumors, while expression of a 2.6 kb TGF beta mRNA transcript can be detected in 70-80% of breast tumors. Interference with (e.g. TGF alpha) or augmentation of (e.g. TGF beta) the effects of these two growth factors may have some potential clinical applications in the treatment of breast cancer.

Breast Neoplasms↗
PubMed1989

Infection with a TGF-alpha retroviral vector transforms normal mouse mammary epithelial cells but not normal rat fibroblasts.

A cDNA clone of human transforming growth factor alpha (TGF-alpha) was introduced into two different retroviral vectors under the transcriptional control of either the viral LTR, vector 1520, or an internal mouse metallothionein-1 promoter, vector 1522. Infection of normal rat kidney fibroblasts (NRK-49F) and mouse mammary epithelial cells (NOG-8), followed by selection, allowed isolation of individual colonies expressing human TGF-alpha. NRK-49F and NOG-8 1520 infectants conditioned their media with equivalent amounts of TGF-alpha protein but responded differently to autocrine stimulation. NOG-8 infectants formed colonies in soft agar and tumors in nude mice. However, while the NRK-49F infectants proliferated in the presence of transforming growth factor beta (TGF-beta), a response that requires epidermal growth factor (EGF) or TGF-alpha, they exhibited neither anchorage independent growth nor tumorigenicity. NRK-49F cells infected with the 1522 vector produced five-fold more TGF-alpha than the 1520 infectants. Increasing the level of TGF-alpha production by the NRK-49F cells in this way was sufficient to promote agar growth of the cells in the presence of TGF-beta but insufficient to promote tumorigenesis. The EGF receptor level is approximately ten-fold higher on the NOG-8 epithelial cells than on the NRK-49F fibroblast. This fact, in conjunction with the experimental results, suggest that the target cell type and its ability to respond to TGF-alpha is as critical for autocrine stimulation as the amount of growth factor produced by the cells.

Animals↗
PubMed1988

Differential growth sensitivity to 4-cis-hydroxy-L-proline of transformed rodent cell lines.

The effect of 4-cis-hydroxy-L-proline (CHP), a proline analogue, on the anchorage-dependent and -independent growth of several transformed rodent cell lines was studied. Mouse NIH-3T3 fibroblasts transformed by a variety of different oncogenes (Ki-ras, mos, src, fms, fes, met, and trk) by a DNA tumor virus (SV40) or by a chemical carcinogen (N-methylnitrosourea) were all found to be more sensitive (50% inhibitory dose, 20 to 55 micrograms/ml) to the dose-dependent inhibitory effects of CHP on growth in monolayer culture than were NIH-3T3 cells (50% inhibitory dose, 120 micrograms/ml). CHP was generally found to be even more effective in inhibiting the growth of these transformed cells as colonies in soft agar than in monolayer cultures. In addition, rat embryo fibroblasts (CREF) and normal rat kidney fibroblasts (NRK) after transformation with a Ki-ras oncogene exhibit a similar increase in their sensitivity to CHP-induced growth inhibition. Treatment of NRK cells with transforming growth factor alpha (TGF-alpha) and beta (TGF-beta), which reversibly induces phenotypic transformation of these cells, increases their sensitivity to CHP to a level comparable with that observed in Ki-ras-transformed NRK cells (K-NRK). The growth inhibitory effects of CHP are reversible, since removal of CHP results in a normal resumption of cell growth. CHP uptake occurs primarily through the Na+- and energy-dependent neutral amino acid transport A system, which is 6- to 7-fold more elevated in K-NRK cells compared with NRK cells. Treatment of NRK cells with TGF-alpha and/or -beta increases the uptake of [3H]methylaminoisobutyric acid on the A system to a level that is similar to that found in K-NRK cells. The functions of the Na+/K+ and Na+/H+ exchange systems are apparently necessary for the enhanced A system activity, since ouabain and amiloride can inhibit the uptake of [3H]methylaminoisobutyric acid in K-NRK cells and in NRK cells treated with TGF-alpha and/or -beta. The activity of the A system is specifically increased in K-NRK and in TGF-alpha- and/or -beta-treated NRK cells, since the other two major neutral amino acid uptake systems, the ASC and the L systems, and the Ly+ system for basic amino acid uptake show no apparent changes in their activity in NRK cells after treatment with TGF-alpha and/or -beta or in these cells after transformation with the Ki-ras oncogene. These results suggest that the differential growth sensitivity to CHP of transformed rodent cells and of normal fibroblasts treated with TGF-alpha and/or -beta is due in part to an elevated uptake of this amino acid analogue on the neutral amino acid transport A system.

Amiloride↗
PubMed1988

Growth of cells on a perfluorocarbon-medium interphase: a quantitative assay for anchorage-independent cell growth.

A high density, purified, nontoxic solvent, heptacosafluorotributylamine (FC43), was successfully used as a culture surface for growing several normal and oncogene-transformed cell lines under anchorage-independent conditions. Normal rat kidney (NRK) fibroblasts and the normal mammary epithelial cell lines NMuMG and A1, clone N4, of murine and human origin, respectively, failed to grow at a FC43 growth medium interphase or in soft agar in the absence of transforming growth factor alpha (TGF alpha) and transforming growth factor beta (TGF beta). However, NRK fibroblasts transformed with the Kirsten ras viral oncogene (K-NRK) or NMuMG cells transformed with a point-mutated c-Harvey-ras proto-oncogene or polyoma middle T-transforming gene (NMuMG-rasH and NMuMG-pyt, respectively) exhibited rapid growth and formed large colonies when cultured on an FC43-medium interphase. In addition, NRK cells treated with TGF alpha and TGF beta and K-NRK cells grown on FC43 exhibited a sensitivity to the growth inhibitory effects of 4-cis-L-hydroxyproline comparable to that observed for the same cells grown in soft agar. These results demonstrated that the two-phase assay system (FC43-growth medium interphase) may be superior to soft agar for monitoring the anchorage-independent growth of cells because of the ease of cell plating, the ability to recover cells and secreted products from the upper aqueous phase, and the shorter growth period required to complete the assay (3-4 days).

Animals↗
PubMed1988

Induction of transforming growth factor alpha expression in mouse mammary epithelial cells after transformation with a point-mutated c-Ha-ras protooncogene.

NOG-8 ras cells are a normal mouse mammary epithelial cell line transfected with a plasmid containing a glucocorticoid-inducible mouse mammary tumor virus long terminal repeat linked to the activated c-Ha-ras protooncogene. After addition of dexamethasone, there is a rapid induction (within 1-3 h) of p21ras protein that is concomitant with a parallel induction of the c-Ha-ras specific mRNA. After 4-6 days of dexamethasone treatment, NOG-8 ras cells are able to grow as colonies in semisolid medium. Between 9 and 12 days of dexamethasone treatment, there is a 5- to 6-fold increase of transforming growth factor alpha (TGF alpha) activity in the conditioned medium from NOG-8 ras cells. A 60-65% reduction in epidermal growth factor cell surface receptors on NOG-8 ras cells also occurs during this time interval. A 3- to 4-fold increase of the expression of a specific TGF alpha mRNA can be detected within 2 days of dexamethasone treatment, preceding the increase in TGF alpha protein found in the conditioned medium. Exogenous TGF alpha is able to stimulate in a dose-dependent fashion the anchorage-dependent and anchorage-independent growth of NOG-8 ras cells to a level comparable to that observed in dexamethasone treated ras-transformed NOG-8 ras cells. These results suggest that the enhanced expression of TGF alpha after induction of an activated ras protooncogene may be necessary for the anchorage-independent growth and subsequent morphological changes and the enhanced growth rate observed in ras-transformed mammary epithelial cells.

Animals↗
PubMed1988

Disordered metabolism of microfilament proteins, tropomyosin and actin, in mouse mammary epithelial cells expressing the Ha-ras oncogene.

Synthesis of 37- and 41-kD tropomyosins (TM) is suppressed in fibroblasts expressing transforming oncogenes, which may contribute to the deranged microfilament structure seen in such cells (Cooper et al., Mol. Cell. Biol. 5, 972, 1985). To determine whether TM metabolism was also deranged when epithelial cells expressed a transforming oncogene, we studied cultured mouse mammary epithelial cells which express the activated c-Ha-ras oncogene either constitutively or through glucocorticoid activation of the oncogene linked to a mouse mammary tumor virus (MMTV) promoter. The epithelial cells expressed three major TM species, one at 37 kD and two at 35 kD, but lacked expression of a 41 kD TM typically found in fibroblasts. In oncogene-expressing cells synthesis of the 37 kD TM was not suppressed but synthesis of actin was increased 2-fold. Actin entered the cytoskeleton (CSK) normally, but TM accumulated in the CSK with a 50% reduction from normal in TM:actin ratio. Thus, in both epithelial cells and fibroblasts expressing transforming ras oncogenes, the metabolism of TM and actin is disordered so as to produce TM-deficient cytoskeletal structures which may be functionally or structurally defective. However, the result is achieved by different effects on metabolism of these proteins in the two cell types, suggesting that cellular responses to oncogene actions may be conditioned by the state of cell differentiation.

Actins↗
PubMed1987

Effects of ouabain on NIH/3T3 cells transformed with retroviral oncogenes and on human tumor cell lines.

Both murine and human cell lines transformed by the v-Ki-ras gene have been shown to be much more sensitive to the toxic effects of the cardiac glycoside ouabain than their respective controls. This differential toxicity has previously been used in the isolation of flat revertant clones from populations of Kirsten murine sarcoma virus transformed NIH/3T3 cells. Here, we have undertaken a further characterization of this phenomenon in murine and human tumor cells. Two different techniques, a 51Cr-release assay and a quantitative Crystal violet elution assay, have been employed to compare the sensitivities to ouabain of normal and v-Ki-ras-transformed NIH/3T3 cells. In each assay, ras-transformed NIH/3T3 cell lines displayed an increased sensitivity to ouabain as compared to the parental NIH/3T3 cell line, both in dose-response and in time-course experiments. In a separate study, ouabain was also able to inhibit the growth in semi-solid medium of 2 v-Ki-ras-transformed NIH/3T3 cell lines (DT and K-NIH) in a dose-dependent fashion. The same concentrations of ouabain were effective in both the 51Cr-release and Crystal violet assays. To address the question of whether increased sensitivity to ouabain is a specific result of transformation with the ras oncogene or is a common event which accompanies transformation by other oncogenes, we have screened a variety of transformed NIH/3T3 derivatives. All of these lines displayed an increased sensitivity to ouabain when compared to the parental NIH/3T3 cell line.

Animals↗
PubMedDate not supplied

Synergistic growth inhibition and induction of apoptosis by a novel mixed backbone antisense oligonucleotide targeting CRIPTO in combination with C225 anti-EGFR monoclonal antibody and 8-Cl-cAMP in human GEO colon cancer cells.

We have evaluated the antiproliferative effect of a novel mixed backbone antisense oligonucleotide generated against the 5'-coding region of the human CRIPTO mRNA in GEO human colon cancer cells. We have also evaluated the effects of this anti-CRIPTO antisense oligonucleotide in combination with a chimeric anti-human epidermal growth factor receptor (EGFR) monoclonal antibody (MAb C225) and with 8-Cl-cAMP, a cAMP analog that specifically inhibits type I protein kinase A (PKAI), since a functional EGFR-driven autocrine pathway is operative and PKAI is overexpessed in GEO colon cancer cells. Treatment with a single agent at low doses determined a 15-35% growth inhibition. A synergistic antiproliferative effect was observed when combinations of two agents were used with a co-operativity quotient ranging between 1.5 and 2.2. Furthermore, the combined treatment with all three drugs caused an almost complete suppression of the ability of GEO cells to form colonies in soft agar. We next evaluated whether any combination of 8-Cl-cAMP, the anti-CRIPTO antisense oligonucleotide and MAb C225 could induce programmed cell death in GEO cells. Treatment with each agent alone at all doses tested did not cause DNA fragmentation. The treatment with any combination of two agents was not able to induce apoptosis. In contrast, treatment with all three compounds determined an approximately three-fold increase in DNA fragmentation. In conclusion, the combination of selective antineoplastic agents directed against different but related key signal tranduction pathways efficiently inhibits cell growth and causes apoptosis in human colorectal cancer cells.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMedDate not supplied

Effect of thymic extract 'thymostimulin' on the incidence of infections and myelotoxicity during adjuvant chemotherapy for breast cancer.

A clinical trial was made to evaluate the effectiveness of thymostimulin (TST), a bovine thymic extract, in preventing infections in breast cancer patients treated with polychemotherapy. Fifty-one women treated with adjuvant CMF were randomly divided into two groups: 25 patients received TST plus chemotherapy and 26 patients were subjected to chemotherapy only. Periodic clinical and laboratory checks were performed for at least three months to monitor the occurrence of infections and variations in immunological parameters. Infections (mostly cystitis, conjunctivitis and stomatomucositis) were observed in 37% of the TST treated patients and in 77% of the controls. (p less than 0.005). Serum immunoglobulin concentrations in the two groups were not significantly different, while quantitative analysis of peripheral T lymphocyte subsets showed a higher incidence of decreased T4/T8 ratio in the control group (p = 0.055). Finally, there was a significantly lower incidence of myelotoxicity in the TST treated patients (p less than 0.0005). In conclusion, thymostimulin seems effective in preventing some of the commonest side effects of cancer chemotherapy.

Adult↗
PubMedDate not supplied

c-Ha-ras transfection and expression of MDR-related genes in MCF-10A human breast cell line.

BACKGROUND: We studied the relationship between ras transfection and the drug resistance phenotype in the MCF-10A cell line (a non-transformed immortalized human breast epithelial cell line). MATERIALS AND METHODS: Parental (MCF-10A) and c-Ha-ras transfected (MCF-10A H) cell lines were tested for resistance to Doxorubicin, Maphosphamide and Cisplatinum, by evaluating the inhibition of [3H]-thymidine incorporation. Cells were also examined for the expression of different resistance mechanisms by immunocytochemical and RT-PCR methods. RESULTS: ras-transfected cells were much more resistant to Cis-platinum than parental ones. GST-pi the GST isoenzyme frequently involved in human cancers) increased only in transfected cells. No expression of any other resistance mechanisms (MDR, MRP, LRP) was found by immunocytochemistry either in parental or in transfected cells; nevertheless, the more sensitive RT-PCR tests detected mrp products in parental and in transfected cells: gene expression levels were low and equivalent in both cell lines. CONCLUSIONS: ras transfection can induce resistance to Cis-platinum by increasing GST-pi expression.

ATP Binding Cassette Transporter, Subfamily B, Mem↗