Enhancement of antitumor activity of ionizing radiation by combined treatment with the selective epidermal growth factor receptor-tyrosine kinase inhibitor ZD1839 (Iressa).PURPOSE: The epidermal growth factor receptor (EGFR) is expressed in the majority of human epithelial cancers and has been implicated in the development of cancer cell resistance to cyotoxic drugs and to ionizing radiation. EXPERIMENTAL DESIGN: We used ZD1839, a selective small molecule EGFR tyrosine kinase inhibitor currently in clinical development. We tested the antiproliferative and the proapoptotic activity of ZD1839 in combination with ionizing radiation in human colon (GEO), ovarian (OVCAR-3), non-small cell lung (A549 and Calu-6), and breast (MCF-7 ADR) cancer cell lines. The antitumor activity of this combination was also tested in nude mice bearing established GEO colon cancer xenografts. RESULTS: With ionizing radiation or ZD1839, a dose-dependent growth inhibition was observed in all of the cancer cell lines growing in soft agar. A cooperative antiproliferative and proapoptotic effect was obtained when cancer cells were treated with ionizing radiation followed by ZD1839. This effect was accompanied by inhibition in the expression of the antiapoptotic proteins bcl-xL and bcl-2, and by a suppression of the activated (phosphorylated) form of akt protein. Treatment of mice bearing established human GEO colon cancer xenografts with radiotherapy (RT) resulted in a dose-dependent tumor growth inhibition that was reversible upon treatment cessation. Long term GEO tumor growth regressions were obtained after RT in combination with ZD1839. This resulted in a significant improvement in survival of these mice as compared with the control group (P < 0.001), the RT-treated group (P < 0.001), or the ZD1839-treated group (P < 0.001). The only mice alive 10 weeks after tumor cell injection were in the RT-plus-ZD1839 group. Furthermore, 10% of mice in this group were alive and tumor-free after 26 weeks. Similar results were obtained in mice bearing established human A549 lung adenocarcinoma xenografts. Finally, the combined treatment with RT plus ZD1839 was accompanied by a significant potentiation in the inhibition of transforming growth factor alpha, vascular epidermal growth factor, and basic fibroblast growth factor expression in cancer cells, which resulted in significant antiangiogenic effects as determined by immunohistochemical count of neovessels within the GEO tumors. CONCLUSION: This study provides a rationale for evaluating in cancer patients the combination of ionizing radiation and selective EGFR tyrosine kinase inhibitors such as ZD1839.
Epithelial-mesenchymal transition in prostate cancer: an overview// Micaela Montanari 1,2 , Sabrina Rossetti 1 , Carla Cavaliere 1,3 , Carmine D’Aniello 1,4 , Maria Gabriella Malzone 1,5 , Daniela Vanacore 1 , Rossella Di Franco 1,6 , Elvira La Mantia 1,5 , Gelsomina Iovane 1,7 , Raffaele Piscitelli 1 , Raffaele Muscariello 8 , Massimiliano Berretta 9 , Sisto Perdonà 8 , Paolo Muto 6 , Gerardo Botti 5,10 , Attilio Antonio Montano Bianchi 11 , Bianca Maria Veneziani 2 and Gaetano Facchini 1,7 1 Progetto ONCONET2.0, Linea Progettuale 14 per L’implementazione della Prevenzione e Diagnosi Precoce del Tumore alla Prostata e Testicolo, Regione Campania, Italy 2 Department of Molecular Medicine and Medical Biotechnologies, University of Naples “Federico II”, Naples, Italy 3 Department of Onco-Ematology Medical Oncology, S.G. Moscati Hospital of Taranto, Taranto, Italy 4 Division of Medical Oncology, A.O.R.N. dei COLLI “Ospedali Monaldi-Cotugno-CTO”, Naples, Italy 5 Pathology Unit, Istituto Nazionale Tumori “Fondazione G. Pascale”, IRCCS, Naples, Italy 6 Radiation Oncology, Istituto Nazionale per lo Studio e la Cura dei Tumori ‘Fondazione Giovanni Pascale’, IRCCS, Naples, Italy 7 Department of Uro-Gynaecological Oncology, Division of Medical Oncology, Istituto Nazionale Tumori ‘Fondazione G. Pascale’, IRCCS, Naples, Italy 8 Department of Uro-Gynaecological Oncology, Division of Urology, Istituto Nazionale Tumori ‘Fondazione G. Pascale’, IRCCS, Naples, Italy 9 Department of Medical Oncology, CRO Aviano, National Cancer Institute, Aviano, Italy 10 Scientific Directorate, Istituto Nazionale Tumori ‘Fondazione G. Pascale’, IRCCS, Naples, Italy 11 Directorate-General for Management, Istituto Nazionale Tumori ‘Fondazione G. Pascale’, IRCCS, Naples, Italy Correspondence to: Micaela Montanari, email: // Keywords : prostate cancer; epithelial-mesenchymal transition; androgen receptor; TGF-β signaling; EGF/EGFR Received : November 10, 2016 Accepted : February 15, 2017 Published : February 25, 2017 Abstract Prostate cancer is a main urological disease associated with significant morbidity and mortality. Radical prostatectomy and radiotherapy are potentially curative for localized prostate cancer, while androgen deprivation therapy is the initial systemic therapy for metastatic prostate disease. However, despite temporary response, most patients relapse and evolve into castration resistant cancer. Epithelial-mesenchymal transition (EMT) is a complex gradual process that occurs during embryonic development and/or tumor progression. During this process, cells lose their epithelial characteristics and acquire mesenchymal features. Increasing evidences indicate that EMT promotes prostate cancer metastatic progression and it is closely correlated with increased stemness and drug resistance. In this review, we discuss the main molecular events that directly or indirectly govern the EMT program in prostate cancer, in order to better define the role and the mechanisms underlying this process in prostate cancer progression and therapeutic resistance.
Combination of a selective cyclooxygenase-2 inhibitor with epidermal growth factor receptor tyrosine kinase inhibitor ZD1839 and protein kinase A antisense causes cooperative antitumor and antiangiogenic effect.PURPOSE: Epidermal growth factor receptor (EGFR) and protein kinase A type I(PKAI) play an important role in the control of cancer cell growth and angiogenesis. Inhibitors of EGFR and PKAI have antitumor activity in vitro and in vivo in a variety of tumor types, and some of these agents are active after oral administration. Increasing evidence shows that cyclooxygenase (COX)-2 also plays a role in promoting cancer cell proliferation and angiogenesis. COX-2 expression can be induced by EGFR activation and is regulated by cAMP and PKA. Combination of an EGFR inhibitor with a nonselective COX-1/COX-2 inhibitor prevents the development of intestinal cancer in nude mice. Therefore, we investigated whether any cooperative antitumor effect can be obtained by the combined blockade of COX-2, EGFR, and PKAI. EXPERIMENTAL DESIGN: The COX-2 inhibitor SC-236 was combined with the selective EGFR tyrosine kinase inhibitor ZD1839 (Iressa) and the DNA/RNA-mixed backbone oligonucleotide AS-PKAI to study their effect on human cancer growth and angiogenesis, measuring vascular endothelial growth factor (VEGF) and basic fibroblast growth factor expression and vessel formation, in vitro and after oral administration of these agents in mice. RESULTS: A cooperative effect was observed with SC-236 in combination with either ZD1839 or AS-PKAI, as well as with all three agents together, on the proliferation of human colon and breast cancer cells in soft agar at doses that were ineffective for each agent alone. The antiproliferative effect was accompanied by inhibition of COX-2 expression. Moreover, combination of SC-236 with either agent or the triple combination markedly reduced VEGF secretion in the conditioned medium and completely suppressed VEGF and basic fibroblast growth factor expression. In nude mice bearing human colon cancer xenografts, a low, noninhibitory dose of SC-236 with ZD1839 and AS-PKAI, all given p.o., caused a dramatic cooperative antitumor effect, with no histological evidence of tumor in 60% of mice 5 weeks after treatment withdrawal, at which time all mice were alive. Moreover, analysis of tumor specimens revealed inhibition of vessel formation and expression of COX-2 and VEGF. CONCLUSIONS: This is the first demonstration that three novel agents blocking multiple signaling pathways, in absence of cytotoxic drugs, may have a potent antitumor and antiangiogenic activity after oral administration. Because all agents are under clinical evaluation, our results provide a rationale to translate this feasible therapeutic strategy into a clinical setting.
Adenosine 3′,5′-Monophosphate Mediates Both the Mitogenic Effect of Thyrotropin and Its Ability to Amplify the Response to Insulin-Like Growth Factor I in FRTL5 Cells*In previous studies we have demonstrated that bovine TSH (bTSH) and insulin-like growth factor I (IGF-I) independently stimulate both the incorporation of [3H]thymidine into DNA and replication in quiescent FRTL5 cells. In the case of TSH, evidence was presented that these responses are cAMP mediated. In addition, responses of thymidine incorporation are greatly amplified when particular concentrations of the two agents are added together, but this effect diminishes as the concentration of either bTSH or IGF-I is increased. The present experiments were undertaken to obtain further information concerning the mechanism of the independent mitogenic effects of bTSH and IGF-I and to explore the nature of the biphasic synergistic interaction with respect to thymidine incorporation that occurs when bTSH and IGF-I are added together. Verification that the increases in [3H]thymidine incorporation induced by bTSH and IGF-I, alone and together, are truly reflective of increases in DNA synthesis was obtained in experiments in which labeled nuclei were counted in cultures of cells grown in the presence of one or both mitogenic agents to which [3H]thymidine had been added. In these studies the number of cells with labeled nuclei was increased markedly by each of the two agents, and the response when the two mitogens were added together was far greater than the sum of their individual effects. Over a range of concentrations which included those that elicit a mitogenic response in FRTL5 cells, IGF-I, unlike bTSH, failed to increase cAMP generation when added alone. Moreover, IGF-I did not significantly enhance the cAMP response to varying concentrations of bTSH. A concentration-dependent increase in the incorporation of [3H]thymidine into DNA was induced by culturing cells in the presence of the cAMP analog (Bu)2cAMP (Bt2cAMP), the phosphodiesterase inhibitor isobutylmethylxanthine, and the stimulator of adenylate cyclase forskolin. When increasing concentrations of these agents were added together with IGF-I, a biphasic pattern of response of DNA synthesis, mimicking that produced by the combination of IGF-I and increasing concentrations of bTSH, was observed. Further evidence that cAMP mediates the mitogenic response to bTSH was the observation that adenosine inhibited the stimulation of both cAMP generation and DNA synthesis that bTSH produced. Although preincubation of quiescent FRTL5 cells for 24 h in the presence of bTSH resulted in only a small increase in DNA synthesis, measured during the last 3 h of a subsequent 24-h incubation carried out in the absence of bTSH, it greatly amplified the response to IGF-I added alone during the second incubation. These effects of preincubating cells with bTSH were mimicked by preincubating them with Bt2cAMP. Although preincubations with IGF-I also increased DNA synthesis during a second incubation in the absence of any additive, it inhibited, rather than enhanced, the mitogenic response to both bTSH and Bt2cAMP during the second incubation. These data indicate that the pathways by which bTSH and IGF-I stimulate growth in FRTL5 cells are different; the former is mediated by cAMP while the latter is not. The bTSH-initiated component of the amplifying interaction between bTSH and IGF-I with respect to DNA synthesis in these cells is also cAMP dependent. This amplification results from a priming action of bTSH on the subsequent response to IGF-I; this action persists after bTSH is withdrawn and is also cAMP dependent. (Endocrinology122: 127–132,1988)