RESUMO
OBJECTIVE: To investigate the potential mechanisms that curcumin reverses 5-fluorouracil (5-FU) multidrug resistance (MDR). METHODS: Cell growth and the inhibitory rate of curcumin (2-25 µg/mL) and/or 5-FU (0.05-1000 µg/mL) on human colon cancer HCT-8 and HCT-8/5-FU (5-FU-resistant cell line) were determined using cell counting kit-8 (CCK-8) assay. Apoptosis and cell cycle after 5-FU and/or curcumin treatment were detected by flow cytometry (FCM) and transmission electron microscopy (TEM). The expression of the multidrug resistance related factors p-glycoprotein (P-gp) and heat shock protein 27 (HSP-27) genes and proteins were analyzed by reverse transcription polymerase chain reaction (RT-PCR) and Western blotting (WB), respectively. RESULTS: The inhibitory rate of curcumin or 5-FU on HCT-8 and HCT-8/5-FU cells proliferation at exponential phase were in a dosedependent manner, HCT-8 cell line was more sensitive to curcumin or 5-FU when compared the inhibitory rate of HCT-8/5-FU. The 50% inhibitory concentration (IC50) of combination 5-FU and curcumin (4.0 µg/mL) in HCT-8/5-FU was calculated as 179.26 µg/mL, with reversal fold of 1.85. Another IC50 of combination 5-FU and curcumin (5.5 µg/mL) in HCT-8/5-FU was calculated as 89.25 µg/mL, with reversal fold of 3.71. Synergistic effect of 5-FU and curcumin on HCT-8 and HCT-8/5-FU cells were found. The cell cycle analysis performed by FCM showed that HCT-8 and HCT-8/5-FU cells mostly accumulated at G0/G1 phase, which suggested a synergistic effect of curcumin and 5-FU to induce apoptosis. FCM analysis found that the percentage of apoptosis of cells treated with curcumin, 5-FU and their combination were significantly increased compared to the control group (P<0.05), and the percentage of apoptosis of the combination groups were slightly higher than other groups (P<0.05). The mRNA levels of P-gp (0.28±0.02) and HSP-27 (0.28±0.09) in HCT-8/5-FU cells treated with combination drugs were lower than cells treated with 5-FU alone (P-gp, 0.48±0.07, P=0.009; HSP-27, 0.57±0.10, P=0.007). The protein levels of P-gp (0.25±0.06) and HSP-27 (0.09±0.02) in HCT-8/5-FU cells treated with combination drugs were decreased when compared to 5-FU alone (P-gp, 0.46±0.02, P=0.005; HSP-27, 0.43±0.01, P=0.000). CONCLUSIONS: Curcumin can inhibit the proliferation of human colon cancer cells. Curcumin has the ability of reversal effects on the multidrug resistance of human colon cancer cells lines HCT-8/5-FU. Down-regulation of P-gp and HSP-27 may be the mechanism of curcumin reversing the drug resistance of HCT-8/5-FU to 5-FU.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Apoptose/efeitos dos fármacos , Neoplasias do Colo/patologia , Curcumina/farmacologia , Regulação para Baixo/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Fluoruracila/farmacologia , Proteínas de Choque Térmico HSP27/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias do Colo/genética , Neoplasias do Colo/ultraestrutura , Regulação para Baixo/efeitos dos fármacos , Sinergismo Farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Proteínas de Choque Térmico HSP27/metabolismo , Humanos , RNA Mensageiro/genética , RNA Mensageiro/metabolismoRESUMO
AIM: To explore the features and prognostic value of lymph node metastasis in patients with T1-stage colorectal cancer (CRC). METHODS: In all, 321 cases of T1-stage CRC were selected from 10132 patients with CRC who received surgical therapy in six large-scale hospitals in China and were retrospectively analyzed. Univariate and multivariate analyses were performed to analyze the risk factors for lymphatic metastasis. A survival analysis was then performed to analyze the prognostic value of lymph node metastasis. RESULTS: The occurrence rate of T1 stage was 3.17% (321/10132); of these patients, the lymph node metastasis rate was 8.41% (27/321), and the non-lymph node metastasis rate was 91.59% (294/321). Univariate analysis showed that preoperative serum CEA, preoperative serum CA199, preoperative serum CA724, vascular invasion, and degree of differentiation were associated with lymph node metastasis in T1-stage CRC (P < 0.05 for all). Multivariate analysis indicated that preoperative serum CA724, vascular invasion, and degree of differentiation were closely related to lymph node metastasis (P < 0.05 for all). Log-rank survival analysis showed that age, preoperative serum CEA, preoperative serum CA199, vascular invasion, degree of differentiation, and lymph node metastasis (χ2 = 24.180, P < 0.001) were predictors of 5-year overall survival (OS) (P < 0.05 for all). COX regression analysis demonstrated that preoperative serum CA199 and lymph node metastasis (HR = 5.117; P < 0.05; 95%CI: 0.058-0.815) were independent prognostic indicators of 5-year OS in patients with T1-stage CRC (P < 0.05 for both). CONCLUSION: The morbidity of T1-stage CRC was 3.17% for all CRC cases. Preoperative serum CA724, vascular invasion, and degree of differentiation are independent risk factors for lymph node metastasis. Lymph node metastasis is an independent prognostic factor for OS in patients with T1-stage CRC.
