PAX3–FKHR sensitizes human alveolar rhabdomyosarcoma cells to camptothecin-mediated growth inhibition and apoptosis

Abstract

Patients with alveolar rhabdomyosarcoma (ARMS) have poorer response to conventional chemotherapy and lower survival rates than those with embryonal RMS (ERMS). By high-throughput screening, we identified camptothecin as an ARMS-selective inhibitor. Camptothecin more efficiently inhibited proliferation and induced apoptosis in Rh30 (ARMS) than RD (ERMS) cells. Ectopic expression of the PAX3-FKHR (PF) fusion protein in RD cells significantly increased sensitivity, whereas siRNA knockdown of PF decreased sensitivity of Rh30 cells to camptothecin. The sensitization required a transcriptionally active PF, and camptothecin downregulated levels of PF protein. These findings suggest that it is feasible to develop agents that preferentially block the growth of ARMS.

Synthesis, transformation and biological evaluation of 2,3-secotriterpene acetylhydrazones and their derivatives

“…It has been reported that camptothecin induces apoptosis and inhibits proliferation of RD cells [33].…”

PAX3-FKHR Regulates the Expression of Pleiotrophin to Mediate Motility in Alveolar Rhabdomyosarcoma Cells

“…Rh30, Rh41, RD, HEK293T, NIH3T3 cells, and the establishment of PAX3-FKHR knockdown (KD1) and control (CON) stable clones of Rh30 have been described previously [5–7]. Phenol red–free Dulbecco’s modified Eagle’s medium (Invitrogen, Carlsbad, CA) was used for all luminescence assays.…”

“…Extraction of total RNA, preparation of cDNA, PCR primers for PAX3-FKHR and glucose-6-phosphate dehydrogenase (GAPDH), the conditions for PCR, and the quantitation of mRNA levels have been previously described [5, 7, 8]. Briefly, the cycle threshold (Ct) values of each gene of interest and of GAPDH were calculated for each sample.…”

“…However, no pharmacologic inhibitor of PAX3-FKHR is currently available; identification of druggable transcription targets of PAX3-FKHR that are also downstream effectors of PAX3-FKHR–mediated cell migration and metastasis may lead to novel therapeutic approaches for treating ARMS [1]. Significant effort has been made to identify transcription targets of PAX3-FKHR, and several transcription targets of PAX3-FKHR that are involved in ARMS cell migration have been reported [1, 5–7]. …”

Protein Phosphatase 2Cβl Regulates Human Pregnane X Receptor-Mediated CYP3A4 Gene Expression in HepG2 Liver Carcinoma Cells

“…The RT-CES assay (ACEA Biosciences, San Diego, CA) was used to monitor real-time cell proliferation of HepG2 cells as described previously, and the cell index was derived from the cell status-based cellelectrode impedance (Zeng et al, 2009). In brief, approximately 1 ϫ 10 4 cells were seeded in growth medium onto a 96x e-plate (ACEA Biosciences) and allowed to attach and spread for 12 h before real-time cell proliferation was monitored; the cell index was automatically determined every 60 min for 72 h.…”