herbimycin and Lymphoma--Large-Cell--Anaplastic

To explore correlation of seven apoptosis-related proteins (Hsp90a, p53, MDM2, Bcl-2, Bax, Cytochrome C, and Cleaved caspase3) with clinical outcomes of ALK+ anaplastic large-cell lymphoma (ALCL).. Using immunohistochemistry and immunofluorescence double staining methods, the expressions of these seven apoptosis-associated proteins were studied to clarify their relationship with clinical outcomes of 36 ALK+ and 25 ALK-systemic ALCL patients enrolled between 1996 and 2006. The relationship of these apoptosis-regulating proteins with NPM-ALK status was also evaluated with the tyrosine inhibitor herbimycin A (HA) in vitro by immunocytochemistry, Western blotting and flow cytometric assays.. The presence of Hsp90α-, MDM2-, Bax-, Cytochrome C, and Cleaved caspase3-positive tumor cells was found significantly different in ALK+ and ALK-ALCLs, which was correlated with highly favorable clinical outcome. The Bcl-2- and p53-positive tumor cells were found in groups of patients with unfavorable prognosis. Inhibition of NPM-ALK by HA could reactivate the p53 protein and subsequent apoptosis-related proteins and therefore induced apoptosis in ALK+ ALCL cells.. Our results suggest that these seven proteins might be involved in apoptosis regulation and associated with clinical outcome of ALK+ systemic ALCLs. We also reveal a dynamic chain relation that NPM-ALK regulates p53 expression and subsequent apoptosis cascade in ALK+ ALCLs.

Topics: Adolescent; Adult; Aged; Anaplastic Lymphoma Kinase; Apoptosis; Apoptosis Regulatory Proteins; Benzoquinones; Biomarkers, Tumor; Blotting, Western; Cell Culture Techniques; Cell Survival; Child; Child, Preschool; Disease-Free Survival; Enzyme Inhibitors; Female; Flow Cytometry; Humans; Immunohistochemistry; Kaplan-Meier Estimate; Lactams, Macrocyclic; Lymphoma, Large-Cell, Anaplastic; Male; Microscopy, Fluorescence; Middle Aged; Neoplasm Staging; Prognosis; Protein-Tyrosine Kinases; Receptor Protein-Tyrosine Kinases; Retrospective Studies; Rifabutin; Young Adult

Overexpression and activation of TPM3-ALK tyrosine kinase fusion protein is a causal oncogenic event in the development of Anaplastic Large Cell Lymphoma and Inflammatory Myofibroblastic ALK-positive tumors. Thus, the development of ALK specific tyrosine kinase inhibitors is a current therapeutic challenge. Animal models are essential to assess, in vivo, the efficiency of ALK-oncogene inhibitors and to identify new and/or additional therapeutic targets in the ALK tumorigenesis pathway. Using the tetracycline system to allow conditional and concomitant TPM3-ALK and luciferase expression, we have developed a unique transplant model for bioluminescent TPM3-ALK-induced fibroblastic tumors in athymic nude mice. The reversible TPM3-ALK expression allowed us to demonstrate that this oncogene is essential for the tumor growth and its maintenance. In addition, we showed that this model could be used to precisely assess tumor growth inhibition upon ALK chemical inactivation. As proof of principle, we used the general tyrosine kinase inhibitor herbimycin A to inhibit ALK oncoprotein activity. As expected, herbimycin A treatment reduced tumor growth as assessed both by tumor volume measurement and bioluminescent imaging. We conclude that this transplant model for TPM3-ALK-induced tumors represents a valuable tool not only to accurately and rapidly evaluate in vivo ALK-targeted therapies but also to gain insight into the mechanism of ALK-positive tumor development.

Topics: Anaplastic Lymphoma Kinase; Animals; Antibiotics, Antineoplastic; Benzoquinones; Cell Transformation, Neoplastic; Disease Models, Animal; Drug Screening Assays, Antitumor; Genes, Reporter; Lactams, Macrocyclic; Luciferases; Luminescent Agents; Lymphoma, Large-Cell, Anaplastic; Mice; Mice, Nude; Neoplasm Transplantation; Oncogene Proteins, Fusion; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Receptor Protein-Tyrosine Kinases; Rifabutin; Tropomyosin