epidermal-growth-factor and Leiomyosarcoma

Overexpression of Cripto-1 (CR-1) in FVB/N mice using the MMTV-LTR promoter results in increased mammary tumourigenesis in these female transgenic mice (MMTV-CR-1). Here, we characterize uterine tumours that developed in 15/76 (19.7%) of MMTV-CR-1 female nulliparous or multiparous mice during 24 months of observation compared with 0/33 (0%) of FVB/N normal control mice observed during the same time period (p < 0.01). The uterine tumours collected from the MMTV-CR-1 mice were classified as leiomyosarcomas and found to express the CR-1 transgene by polymerase chain reaction analysis and immunohistochemistry. Detection by western blot analysis showed higher levels of phosphorylated (P) forms of c-src, Akt, GSK-3beta, and dephosphorylated (DP)-beta-catenin in lysates from MMTV-CR-1 uterine leiomyosarcomas in comparison with lysates from normal control FVB/N uteri. Immunostaining showed increased nuclear localization of beta-catenin in the MMTV-CR-1 uterine leiomyosarcomas. Increased immunostaining for CR-1 was detected in 9/13 (69.2%) cases of human leiomyosarcoma compared with staining in 3/15 (20%) human leiomyoma sections. Stronger immunostaining for P-src, P-Akt, P-GSK-3beta and increased nuclear localization of beta-catenin was also seen in human leiomyosarcomas in comparison with leiomyomas. Normal human uterine smooth muscle (UtSM) cells treated with exogenous soluble rhCR-1 showed increased levels of P-src, P-Akt, P-GSK-3beta and dephosphorylated (DP)-beta-catenin and increased proliferation (p < 0.05) and migration (p < 0.01) in comparison with untreated control UtSM cells. Inhibitors against c-src, Akt or beta-catenin, individually or in combination, significantly reduced CR-1-induced migration. These results suggest a role for CR-1 during uterine tumourigenesis either directly by activating c-src and Akt and/or via cross-talk with the canonical Wnt signalling pathway, as suggested by the increased expression of P-GSK-3beta, DP-beta-catenin, and increased nuclear localization of beta-catenin in human and MMTV-CR-1 mice leiomyosarcomas.

Topics: Animals; Blotting, Western; Cell Movement; Cell Proliferation; Cells, Cultured; Epidermal Growth Factor; Female; Gene Expression Regulation, Neoplastic; GPI-Linked Proteins; Humans; Immunohistochemistry; Intercellular Signaling Peptides and Proteins; Leiomyosarcoma; Mammary Tumor Virus, Mouse; Membrane Glycoproteins; Mice; Mice, Transgenic; Neoplasm Proteins; Polymerase Chain Reaction; Promoter Regions, Genetic; Recombinant Proteins; Signal Transduction; Uterine Neoplasms; Wnt1 Protein

Little is known about the regulation of sarcoma proliferation by hormones and/or growth factors. We therefore characterised the in vitro proliferative influence on eight sarcoma cell lines of the platelet-derived growth factor, the insulin-like growth factor 1, triiodothyronine, the epidermal growth factor, the luteinising-hormone-releasing hormone, progesterone, gastrin and 17 beta-oestradiol. The influence of the different factors on the proliferation of sarcoma cell lines was measured by the colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test. Two culture media were studied: (1) a nutritionally poor medium containing 2% of fetal calf serum and (2) a nutritionally rich one containing 5% or 10% FCS both with and without the addition of non-essential amino acids. The results were analysed either by conventional statistical analyses or by a classification method based on a decision-tree approach developed in Machine Learning. This latter method was also compared to other classifiers (such as logistic regression and k nearest neighbours) with respect to its accuracy of classification. Monovariate statistical analysis showed that each of the eight cell lines exhibited sensitivity to at least one factor, and each factor significantly modified the proliferation of five or six of the eight cell lines under study. Of these eight lines one of fibrosarcoma origin was the most "factor-sensitive". Decision-tree-related data analysis enabled the specific pattern of factor sensitivity to be characterised for the three histological types of cell line under study. The effects of hormone and growth factors are significantly influenced by the type of culture medium used. The method used appeared to be an accurate classifier for the kind of data analysed. Sarcoma proliferation can be modulated, at least in vitro, by various hormones and growth factors, and the proliferation of each histopathological type exhibited a distinct sensitivity to different hormone and/or growth-factors.

Topics: Cell Division; Colorimetry; Culture Media; Epidermal Growth Factor; Estradiol; Fibrosarcoma; Gastrins; Gonadotropin-Releasing Hormone; Growth Substances; Hormones; Humans; Insulin-Like Growth Factor I; Leiomyosarcoma; Platelet-Derived Growth Factor; Progesterone; Reproducibility of Results; Rhabdomyosarcoma; Sensitivity and Specificity; Tetrazolium Salts; Thiazoles; Triiodothyronine; Tumor Cells, Cultured

In resting DDT1MF-2 smooth muscle cells, the cytosolic free Ca2+ concentration ([Ca2+]c) was higher than the free Ca2+ concentration in the nucleus ([Ca2+]n). However, this nucleocytosolic [Ca2+] gradient was reversed by Ca2+ agonists like ATP or, as is shown here, by the epidermal growth factor (EGF). The ATP-induced reversal of the nucleocytosolic [Ca2+] gradient was blocked by stimulation of protein kinase C with phorbol 12-myristate 13-acetate or with the diacylglycerol kinase inhibitor R59949, or by inhibition of the Ser/Thr-specific protein phosphatases-1 and -2A with okadaic acid or calyculin A. Moreover, the magnitude of the ATP-induced reversal of the [Ca2+] gradient diminished during prolonged culture of the cells. The EGF-induced [Ca2+] rise in the cytosol and nucleus was blocked by okadaic acid and by the tyrosine kinase inhibitors herbimycin A and psi-tectorigenin. Our data suggest that the nucleocytosolic [Ca2+] gradient is modulated by (de)phosphorylation processes catalyzed by tyrosine protein kinases, by protein kinase C, and by Ser/Thr protein phosphatases-1 and -2A.

Topics: Adenosine Triphosphate; Animals; Benzoquinones; Calcium; Cell Line; Cell Nucleus; Colforsin; Cricetinae; Cytosol; Diacylglycerol Kinase; Epidermal Growth Factor; Ethers, Cyclic; Homeostasis; Kinetics; Lactams, Macrocyclic; Leiomyosarcoma; Marine Toxins; Mesocricetus; Models, Biological; Muscle, Smooth; Okadaic Acid; Oxazoles; Phosphoproteins; Phosphorylation; Phosphotransferases (Alcohol Group Acceptor); Piperidines; Protein Kinase C; Protein Kinases; Protein Tyrosine Phosphatases; Quinazolines; Quinazolinones; Quinones; Rifabutin; Tetradecanoylphorbol Acetate; Time Factors; Tumor Cells, Cultured