piperidines and Rhabdomyosarcoma

The Wnt/β-catenin signaling pathway plays a pivotal role during embryogenesis and its deregulation is a key mechanism in the origin and progression of several tumors. Wnt antagonists have been described as key modulators of Wnt/β-catenin signaling in cancer, with Dickkopf-1 (DKK-1) being the most studied member of the DKK family. Although the therapeutic potential of DKK-1 inhibition has been evaluated in several diseases and malignancies, little is known in pediatric tumors. Only a few works have studied the genetic inhibition and function of DKK-1 in rhabdomyosarcoma. Here, for the first time, we report the analysis of the therapeutic potential of DKK-1 pharmaceutical inhibition in rhabdomyosarcoma, the most common soft tissue sarcoma in children. We performed DKK-1 inhibition via shRNA technology and via the chemical inhibitor WAY-2626211. Its inhibition led to β-catenin activation and the modulation of focal adhesion kinase (FAK), with positive effects on in vitro expression of myogenic markers and a reduction in proliferation and invasion. In addition, WAY-262611 was able to impair survival of tumor cells in vivo. Therefore, DKK-1 could constitute a molecular target, which could lead to novel therapeutic strategies in RMS, especially in those patients with high DKK-1 expression.

Topics: Animals; beta Catenin; Case-Control Studies; Cell Line, Tumor; Focal Adhesion Protein-Tyrosine Kinases; Humans; Intercellular Signaling Peptides and Proteins; Mice, SCID; Molecular Targeted Therapy; Muscles; MyoD Protein; Myogenin; Naphthalenes; Piperidines; Pyrimidines; Rhabdomyosarcoma; RNA, Small Interfering; Wnt Signaling Pathway; Xenograft Model Antitumor Assays

Topics: Adolescent; Aminopyridines; Anaplastic Lymphoma Kinase; Bone Neoplasms; Carbazoles; Chemoradiotherapy; DNA-Binding Proteins; Female; Humans; Lactams; Lactams, Macrocyclic; Oncogene Proteins, Fusion; Piperidines; Pyrazoles; Rhabdomyosarcoma; RNA-Binding Protein FUS; Transcription Factors

Undifferentiated sarcoma has been hypothesized as an intermediate step in the progression of malignant melanoma to rhabdomyosarcoma. The current report describes a new case of rhabdomyosarcomatous transformation in a malignant melanoma and documents the temporal progression of the malignant melanoma to rhabdomyosarcoma in different metastatic sites via undifferentiated sarcoma. A 65-year-old female with a past medical history of malignant melanoma presented with a new lung mass. A core biopsy revealed a malignant spindle cell neoplasm that was negative for all melanocytic markers, suggesting the possibility of a primary pulmonary sarcomatoid carcinoma or sarcoma. The subsequent lobectomy demonstrated an undifferentiated spindle cell neoplasm with areas of rhabdomyoblastic differentiation. Review of the skin lesion and lymph nodes confirmed the diagnosis of the primary cutaneous malignant melanoma, but also revealed that the nodal metastases had largely transformed into an undifferentiated sarcoma with similar morphology as the spindle cell neoplasm in the lung. Molecular studies demonstrated an identical

Topics: Aged; Antineoplastic Combined Chemotherapy Protocols; Azetidines; Biomarkers, Tumor; Cell Transformation, Neoplastic; Diagnosis, Differential; Disease Progression; Drug Resistance, Neoplasm; Female; Humans; Lung; Lung Neoplasms; Melanoma; Neoadjuvant Therapy; Piperidines; Pneumonectomy; Proto-Oncogene Proteins B-raf; Rhabdomyosarcoma; Skin; Skin Neoplasms; Vemurafenib

Compounds were evaluated for antiviral activity in rhabdomyosarcoma (RD) cells against a recent 2014 clinical isolate of enterovirus D68 (EV-D68), a 1962 strain of EV-68D, rhinovirus 87 (RV-87, serologically the same as EV-D68), and enterovirus 71 (EV-71). Test substances included known-active antipicornavirus agents (enviroxime, guanidine HCl, pirodavir, pleconaril, and rupintrivir), nucleobase/nucleoside analogs (3-deazaguanine and ribavirin), and three novel epidithiodiketopiperazines (KCN-2,2'-epi-19, KCN-19, and KCN-21). Of these, rupintrivir was the most potent, with 50% inhibition of viral cytopathic effect (EC50) and 90% inhibition (EC90) of virus yield at 0.0022-0.0053 μM against EV-D68. Enviroxime, pleconaril and the KCN compounds showed efficacy at 0.01-0.3 μM; 3-deazaguanine and pirodavir inhibited EV-D68 at 7-13 μM, and guanidine HCl and ribavirin were inhibitory at 80-135 μM. Pirodavir was active against EV-71 (EC50 of 0.78 μM) but not against RV-87 or EV-D68, and all other compounds were less effective against EV-71 than against RV-87 and EV-D68. The most promising compound inhibiting both virus infections at low concentrations was rupintrivir. Antiviral activity was confirmed for the ten compounds in virus yield reduction (VYR) assays in RD cells, and for enviroxime, guanidine HCl, and pirodavir by cytopathic effect (CPE) assays in A549, HeLa-Ohio-1, and RD cells. These studies may serve as a basis for further pre-clinical discovery of anti-enterovirus inhibitors. Furthermore, the antiviral profiles and growth characteristics observed herein support the assertion that EV-D68 should be classified together with RV-87.

Topics: A549 Cells; Antimetabolites; Antiviral Agents; Benzimidazoles; Enterovirus A, Human; Enterovirus D, Human; Guanine; HeLa Cells; Humans; Oxadiazoles; Oxazoles; Oximes; Picornaviridae; Piperazines; Piperidines; Pyridazines; Rhabdomyosarcoma; Rhinovirus; Ribavirin; Sulfonamides

Several autocrine and paracrine growth factor circuits have been found in human rhabdomyosarcoma cells. In this study we show that endothelin-3 (ET-3), a vasoactive peptide, is produced by human rhabdomyosarcoma cell lines, whereas it is not expressed by human sarcoma cell lines of non-muscle origin. We did not find evidence of a significant autocrine loop; nevertheless ET-3 produced by rhabdomyosarcoma cells can act as a paracrine factor, since it promotes migration of endothelial cells. Moreover ET-3 is present in plasma of mice bearing xenografts of human rhabdomyosarcoma cells, and may be potential new marker of the human rhabdomyosarcoma to be studied further.

Topics: Biomarkers, Tumor; Cell Line, Tumor; Dose-Response Relationship, Drug; Endothelin-3; Humans; Immunoassay; Oligopeptides; Osteosarcoma; Paracrine Communication; Piperidines; Receptors, Endothelin; Reverse Transcriptase Polymerase Chain Reaction; Rhabdomyosarcoma; Sarcoma, Ewing

We have established preclinical models for the development of drug resistance to vincristine (a major drug used in the treatment of pediatric rhabdomyosarcoma) using cell lines. The RD cell line has a mutant P53 phenotype and does not have detectable P-glycoprotein (P-gp) or multidrug resistance-related protein (MRP) despite expressing low levels of mdr-1 mRNA, which encodes P-gp and mrp1 mRNA. Resistant variants of RD were derived by exposure to increasing concentrations of vincristine. This was repeated on six occasions, resulting in three cell lines which could tolerate 64 x the IC(50) concentration. Six independent agents were tested for their ability to prevent the development of resistance in this model. Despite at least 10 attempts, resistance did not develop in the presence of the multidrug resistance (MDR) modulators PSC833, VX710, and XR9576. This strongly suggests that these agents may delay or even prevent the development of resistance to vincristine. This was also confirmed in a second rhabdomyosarcoma cell line, Rh30. In contrast, the agents indomethacin (MRP1 modulator), CGP41251 (protein kinase C inhibitor), and dexrazoxane (putative MDR prevention agent) did not affect the development of resistance in the RD model. Characterization of the resistant cell lines indicated the presence of increased mdr-1 and P-gp expression, which resulted in resistance to the agents doxorubicin, etoposide, and vincristine but not cisplatin. The resistance could be modulated using PSC833 or VX710, confirming that functional P-gp is present. No apparent differences were seen between the resistant cell lines derived in the absence and presence of the various agents. These experiments strongly suggest that the development of MDR may be preventable using modulators of MDR and merit clinical studies to test this hypothesis.

Topics: Antineoplastic Agents; ATP Binding Cassette Transporter, Subfamily B, Member 1; Child; Cisplatin; Cyclosporins; Doxorubicin; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Etoposide; Gene Expression Regulation, Neoplastic; Humans; Indomethacin; Inhibitory Concentration 50; Piperidines; Pyridines; Quinolines; Razoxane; Rhabdomyosarcoma; RNA, Neoplasm; Staurosporine; Time Factors; Tumor Cells, Cultured; Vincristine