RESUMEN
Prostate cancer (PCa) patients receiving the androgen ablation therapy ultimately develop recurrent castration-resistant prostate cancer (CRPC) within 1-3 years. Treatment with caffeic acid phenethyl ester (CAPE) suppressed cell survival and proliferation via induction of G1 or G2/M cell cycle arrest in LNCaP 104-R1, DU-145, 22Rv1, and C4-2 CRPC cells. CAPE treatment also inhibited soft agar colony formation and retarded nude mice xenograft growth of LNCaP 104-R1 cells. We identified that CAPE treatment significantly reduced protein abundance of Skp2, Cdk2, Cdk4, Cdk7, Rb, phospho-Rb S807/811, cyclin A, cyclin D1, cyclin H, E2F1, c-Myc, SGK, phospho-p70S6kinase T421/S424, phospho-mTOR Ser2481, phospho-GSK3α Ser21, but induced p21Cip1, p27Kip1, ATF4, cyclin E, p53, TRIB3, phospho-p53 (Ser6, Ser33, Ser46, Ser392), phospho-p38 MAPK Thr180/Tyr182, Chk1, Chk2, phospho-ATM S1981, phospho-ATR S428, and phospho-p90RSK Ser380. CAPE treatment decreased Skp2 and Akt1 protein expression in LNCaP 104-R1 tumors as compared to control group. Overexpression of Skp2, or siRNA knockdown of p21Cip1, p27Kip1, or p53 blocked suppressive effect of CAPE treatment. Co-treatment of CAPE with PI3K inhibitor LY294002 or Bcl-2 inhibitor ABT737 showed synergistic suppressive effects. Our finding suggested that CAPE treatment induced cell cycle arrest and growth inhibition in CRPC cells via regulation of Skp2, p53, p21Cip1, and p27Kip1.
Asunto(s)
Antineoplásicos/farmacología , Ácidos Cafeicos/farmacología , Proliferación Celular/efectos de los fármacos , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , Puntos de Control de la Fase G1 del Ciclo Celular/efectos de los fármacos , Puntos de Control de la Fase G2 del Ciclo Celular/efectos de los fármacos , Alcohol Feniletílico/análogos & derivados , Neoplasias de la Próstata Resistentes a la Castración/tratamiento farmacológico , Proteínas Quinasas Asociadas a Fase-S/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Animales , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Línea Celular Tumoral , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/genética , Relación Dosis-Respuesta a Droga , Sinergismo Farmacológico , Humanos , Masculino , Ratones Endogámicos BALB C , Ratones Desnudos , Alcohol Feniletílico/farmacología , Fosfatidilinositol 3-Quinasa/metabolismo , Inhibidores de las Quinasa Fosfoinosítidos-3 , Fosforilación , Neoplasias de la Próstata Resistentes a la Castración/enzimología , Neoplasias de la Próstata Resistentes a la Castración/genética , Neoplasias de la Próstata Resistentes a la Castración/patología , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-bcl-2/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Interferencia de ARN , Proteínas Quinasas Asociadas a Fase-S/genética , Transducción de Señal/efectos de los fármacos , Factores de Tiempo , Transfección , Carga Tumoral/efectos de los fármacos , Proteína p53 Supresora de Tumor/genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Androgen ablation therapy is the primary treatment for metastatic prostate cancer. However, 80-90% of the patients who receive androgen ablation therapy ultimately develop recurrent tumors in 12-33 months after treatment with a median overall survival time of 1-2 years after relapse. LNCaP is a commonly used cell line established from a human lymph node metastatic lesion of prostatic adenocarcinoma. We previously established two relapsed androgen receptor (AR)-rich androgen-independent LNCaP sublines 104-R1 (androgen depleted for 12 months) and 104-R2 cells (androgen depleted for 24 months) from AR-positive androgen-dependent LNCaP 104-S cells. LNCaP 104-R1 and 104-R2 mimics the AR-positive hormone-refractory relapsed tumors in patients receiving androgen ablation therapy. Androgen treatment stimulates proliferation of 104-S cells, but causes growth inhibition and G1 cell cycle arrest in 104-R1 and 104-R2 cells. We investigated the protein expression profile difference between LNCaP 104-S vs. LNCaP 104-R1, 104-R2, PC-3, and DU-145 cells as well as examined the sensitivity of these prostate cancer cells to different chemotherapy drugs and small molecule inhibitors. Compared to 104-S cells, 104-R1 and 104-R2 cells express higher protein levels of AR, PSA, c-Myc, Skp2, BCL-2, P53, p-MDM2 S166, Rb, and p-Rb S807/811. The 104-R1 and 104-R2 cells express higher ratio of p-Akt S473/Akt, p-EGFR/EGFR, and p-Src/Src, but lower ratio of p-ERK/ERK than 104-S cells. PC-3 and DU-145 cells express higher c-Myc, Skp2, Akt, Akt1, and phospho-EGFR but less phospho-Akt and phospho-ERK. Overexpression of Skp2 increased resistance of LNCaP cells to chemotherapy drugs. Paclitaxel, androgen, and inhibitors for PI3K/Akt, EGFR, Src, or Bcl-2 seem to be potential choices for treatment of advanced prostate cancers. Our study provides rationale for targeting Akt, EGFR, Src, Bcl-2, and AR signaling as a treatment for AR-positive relapsed prostate tumors after hormone therapy.
Asunto(s)
Antineoplásicos/farmacología , Resistencia a Antineoplásicos , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Proteoma , Andrógenos/farmacología , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Análisis por Conglomerados , Progresión de la Enfermedad , Resistencia a Antineoplásicos/genética , Receptores ErbB , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Ligandos , Masculino , Antígeno Prostático Específico/genética , Neoplasias de la Próstata/genética , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismo , ARN Mensajero/genética , Receptores Androgénicos/química , Receptores Androgénicos/genética , Receptores Androgénicos/metabolismo , Análisis de Secuencia de ADN , Células Tumorales CultivadasRESUMEN
Caffeic acid phenethyl ester (CAPE) is a bioactive component extracted from honeybee hive propolis. Our observations indicated that CAPE treatment suppressed cell proliferation and colony formation of TW2.6 human oral squamous cell carcinoma (OSCC) cells dose-dependently. CAPE treatment decreased G1 phase cell population, increased G2/M phase cell population, and induced apoptosis in TW2.6 cells. Treatment with CAPE decreased protein abundance of Akt, Akt1, Akt2, Akt3, phospho-Akt Ser473, phospho-Akt Thr 308, GSK3ß, FOXO1, FOXO3a, phospho-FOXO1 Thr24, phospho-FoxO3a Thr32, NF-κB, phospho-NF-κB Ser536, Rb, phospho-Rb Ser807/811, Skp2, and cyclin D1, but increased cell cycle inhibitor p27Kip. Overexpression of Akt1 or Akt2 in TW2.6 cells rescued growth inhibition caused by CAPE treatment. Co-treating TW2.6 cells with CAPE and 5-fluorouracil, a commonly used chemotherapeutic drug for oral cancers, exhibited additive cell proliferation inhibition. Our study suggested that administration of CAPE is a potential adjuvant therapy for patients with OSCC oral cancer.