RESUMEN
A natural isoquinoline alkaloid, berberine, has been known to exhibit anti-tumor activity in various cancer cells via inducing cell cycle arrest. However, it has not been investigated whether berberine and its analogs inhibit the growth of rhabdomyosarcoma (RMS), which is the most frequent soft tissue tumor in children. The present study examined the anti-tumor effects of berberine and palmatine on expansions of three human embryonal RMS cell lines; ERMS1, KYM1, and RD. Intracellular incorporation of berberine was relatively higher than that of palmatine in every RMS cell line. Berberine significantly inhibited the cell cycle of all RMS cells at G1 phase. On the other hand, palmatine only suppressed the growth of RD cells. Both of berberine and palmatine strongly inhibited the growth of tumorsphere of RD cells in three-dimensional culture. These results indicate that berberine derivatives have the potential of anti-tumor drugs for RMS therapy.Abbreviations: ARMS: alveolar rhabdomyosarcoma; ERMS: embryonal rhabdomyosarcoma; RMS: rhabdomyosarcoma.
Asunto(s)
Antineoplásicos/farmacología , Alcaloides de Berberina/farmacología , Berberina/farmacología , Proliferación Celular/efectos de los fármacos , Medicamentos Herbarios Chinos/farmacología , Rabdomiosarcoma Alveolar/patología , Rabdomiosarcoma Embrionario/patología , Antineoplásicos/química , Berberina/análogos & derivados , Berberina/química , Alcaloides de Berberina/química , Línea Celular Tumoral , Ciclina D1/genética , Inhibidor p57 de las Quinasas Dependientes de la Ciclina/genética , Evaluación Preclínica de Medicamentos/métodos , Medicamentos Herbarios Chinos/química , Puntos de Control de la Fase G1 del Ciclo Celular/efectos de los fármacos , Expresión Génica/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica , Humanos , Antígeno Ki-67/genética , Conformación Molecular , Simulación del Acoplamiento Molecular , Phellodendron/química , Rabdomiosarcoma Alveolar/metabolismo , Rabdomiosarcoma Embrionario/metabolismoRESUMEN
Alveolar rhabdomyosarcoma is an aggressive pediatric cancer exhibiting skeletal-muscle differentiation. New therapeutic targets are required to improve the dismal prognosis for invasive or metastatic alveolar rhabdomyosarcoma. Protein kinase C iota (PKCι) has been shown to have an important role in tumorigenesis of many cancers, but little is known about its role in rhabdomyosarcoma. Our gene-expression studies in human tumor samples revealed overexpression of PRKCI. We confirmed overexpression of PKCι at the mRNA and protein levels using our conditional mouse model that authentically recapitulates the progression of rhabdomyosarcoma in humans. Inhibition of Prkci by RNA interference resulted in a dramatic decrease in anchorage-independent colony formation. Interestingly, treatment of primary cell cultures using aurothiomalate (ATM), which is a gold-containing classical anti-rheumatic agent and a PKCι-specific inhibitor, resulted in decreased interaction between PKCι and Par6, decreased Rac1 activity and reduced cell viability at clinically relevant concentrations. Moreover, co-treatment with ATM and vincristine (VCR), a microtubule inhibitor currently used in rhabdomyosarcoma treatment regimens, resulted in a combination index of 0.470-0.793 through cooperative accumulation of non-proliferative multinuclear cells in the G2/M phase, indicating that these two drugs synergize. For in vivo tumor growth inhibition studies, ATM demonstrated a trend toward enhanced VCR sensitivity. Overall, these results suggest that PKCι is functionally important in alveolar rhabdomyosarcoma anchorage-independent growth and tumor-cell proliferation and that combination therapy with ATM and microtubule inhibitors holds promise for the treatment of alveolar rhabdomyosarcoma.
Asunto(s)
Isoenzimas/metabolismo , Terapia Molecular Dirigida/métodos , Proteína Quinasa C/metabolismo , Rabdomiosarcoma Alveolar/tratamiento farmacológico , Rabdomiosarcoma Alveolar/enzimología , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Quimioterapia Adyuvante , Sinergismo Farmacológico , Fase G2/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Tiomalato Sódico de Oro/farmacología , Tiomalato Sódico de Oro/uso terapéutico , Humanos , Isoenzimas/deficiencia , Isoenzimas/genética , Ratones , Proteína Quinasa C/deficiencia , Proteína Quinasa C/genética , Interferencia de ARN , ARN Interferente Pequeño/genética , Rabdomiosarcoma Alveolar/metabolismo , Rabdomiosarcoma Alveolar/patología , Vincristina/farmacología , Vincristina/uso terapéuticoRESUMEN
PURPOSE: Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. Current chemotherapy regimes include the topoisomerase II poison etoposide and the transcription inhibitor actinomycin D. Poor clinical response necessitate identification of new agents to improve patient outcomes. METHODS: We assessed the in vitro cytotoxicity (MTT assay) of DNA intercalating agents in five established human RMS cell lines. These include novel classes of transcription inhibitors and topoisomerase poisons, previously shown to have potential as anti-cancer agents. RESULTS: Amongst the former agents, bisintercalating bis(9-aminoacridine-4-carboxamides) linked through the 9-position, and bis(phenazine-1-carboxamides) linked via their side chains, are compared with established transcription inhibitors. Amongst the latter, monofunctional acridine-4-carboxamides related to N-[2-(dimethylamino)ethyl]acridine-4-carboxamide, DACA, are compared with established topoisomerase poisons. CONCLUSIONS: Our findings specifically highlight the topoisomerase poison 9-amino-DACA, its 5-methylsulphone derivative, AS-DACA, and the bis(phenazine-1-carboxamide) transcription inhibitor MLN944/XR5944, currently in phase I trial, as candidates for further research into new agents for the treatment of RMS.