Effect of RBP2 gene silencing on proliferation, migration and invasion of ovarian epithelial cancer SKOV3/DDP cells and its mechanism / 中华肿瘤杂志

Objective: To explore the effect of down-regulation of retinol binding protein 2 (RBP2) expression on the biological characteristics of ovarian cancer cells and its mechanism. Methods: Knockdown of RBP2 and cisplatin (DDP)-resistant ovarian cancer cell line SKOV3/DDP-RBP2i was established, the negative control group and blank control group were also set. Cell counting kit 8 (CCK-8) was used to detect the cell proliferation ability, flow cytometry was used to detect cell apoptosis, scratch test and Transwell invasion test were used to detect cell migration and invasion ability, real-time fluorescent quantitative polymerase chain reaction (RT-qPCR) and western blot were used to detect the expressions of molecular markers related to epithelial-mesenchymal transition (EMT). The effect of RBP2 on the growth of ovarian cancer was verified through experiment of transplanted tumors in nude mice, and the relationships between RBP2 expression and tumor metastasis and patient prognosis were analyzed using the clinical data of ovarian cancer in TCGA database. Results: After down-regulating the expression of RBP2, the proliferation ability of SKOV3/DDP cell was significantly reduced. On the fifth day, the proliferation activities of SKOV3/DDP-RBP2i group, negative control group and blank control group were (56.67±4.16)%, (84.67±3.51) and (87.00±4.00)% respectively, with statistically significant difference (P<0.001). The apoptosis rate of SKOV3/DDP-RBP2i group was (14.19±1.50)%, higher than (8.77±0.75)% of the negative control group and (7.48±0.52)% of the blank control group (P<0.001). The number of invasive cells of SKOV3/DDP-RBP2i group was (55.20±2.39), lower than (82.60±5.18) and (80.80±7.26) of the negative control group and the blank control group, respectively (P<0.001). The scratch healing rate of SKOV3/DDP-RBP2i group was (28.47±2.72)%, lower than (50.58±4.06)% and (48.92±4.63)% of the negative control group and the blank control group, respectively (P<0.001). The mRNA and protein expressions of E-cadherin in the SKOV3/DDP-RBP2i group were higher than those in the negative control group (P=0.015, P<0.001) and the blank control group (P=0.006, P<0.001). The mRNA and protein expression of N-cadherin in SKOV3/DDP-RBP2i group were lower than those in the negative control group (P=0.012, P<0.001) and the blank control group (P=0.005, P<0.001). The mRNA and protein expressions of vimentin in SKOV3/DDP-RBP2i group were also lower than those in the negative control group (P=0.016, P=0.001) and the blank control group (P=0.011, P=0.001). Five weeks after the cells inoculated into the nude mice, the tumor volume of SKOV3/DDP-RBP2i group, negative control group and blank control group were statistically significant different. The tumor volume of SKOV3/DDP-RBP2i group was smaller than those of negative control group and blank control group (P=0.001). Bioinformatics analysis showed that the expression of RBP2 in patients with metastatic ovarian cancer was higher than that without metastasis (P=0.043), and the median overall survival of ovarian cancer patients with high RBP2 expression was 41 months, shorter than 69 months of low RBP2 expression patients (P<0.001). Conclusion: Downregulation of the expression of RBP2 in SKOV3/DDP cells can inhibit cell migration and invasion, and the mechanism may be related to the inhibition of EMT.

The Effect of Metformin Treatment on CRBP-I Level and Cancer Development in the Liver of HBx Transgenic Mice

Retinoids regulate not only various cell functions including proliferation and differentiation but also glucose and lipid metabolism. After we observed a marked up-regulation of cellular retinol-binding protein-I (CRBP-I) in the liver of hepatitis B virus x antigen (HBx)-transgenic (HBx Tg) mice which are prone to hepatocellular carcinoma (HCC) and fatty liver, we aimed to evaluate retinoid pathway, including genes for the retinoid physiology, CRBP-I protein expression, and retinoid levels, in the liver of HBx Tg mice. We also assessed the effect of chronic metformin treatment on HCC development in the mice. Many genes involved in hepatic retinoid physiology, including CRBP-I, were altered and the tissue levels of retinol and all-trans retinoic acid (ATRA) were elevated in the liver of HBx Tg mice compared to those of wild type (WT) control mice. CRBP-I protein expression in liver, but not in white adipose tissue, of HBx Tg mice was significantly elevated compared to WT control mice while CRBP-I protein expressions in the liver and WAT of high-fat fed obese and db/db mice were comparable to WT control mice. Chronic treatment of HBx Tg mice with metformin did not affect the incidence of HCC, but slightly increased hepatic CRBP-I level. In conclusion, hepatic CRBP-I level was markedly up-regulated in HCC-prone HBx Tg mice and neither hepatic CRBP-I nor the development of HCC was suppressed by metformin treatment.

Correlation studies between urinary retinol binding protein and renal tubular damage / 中南大学学报(医学版)

OBJECTIVE@#To study correlation between urinary retinol binding protein (RBP) content and renal tubular damage.@*METHODS@#A total of 1 353 healthy people and 186 patients with renal tubular damage diagnosed by renal biopsy were enrolled. The indicators such as endogenous creatinine clearance rate (Ccr), creatinine(Cr), urinary retinol binding protein(RBP), urinary β(2)-microglobulin(β(2)-MG), urinary N-acety1-beta-D-glucosaminidase (NAG), urine specific gravity(SG), urine osmolality of the 2 groups were examined and compared. Score of tubulointerstitial impairing and all indicators were analyzed by Spearman rank correlation analysis, and the sensitivity and specificity of indicators were calculated.@*RESULTS@#Renal tubular damage was positively correlated with urinary RBP, β2-MG, NAG (r=0.863, P<0.001; r=0.777, P<0.001; r=0.374, P=0.002, respectively), while negatively correlated with urine osmolaling, SG (r=-0.519, P<0.001; r=-0.624, P<0.001, respectively). The specificity and sensitivity for renal tubular damage of RBP were 91.03% and 72.06%.@*CONCLUSION@#RBP is an idea marker for renal tubular damage, and is useful to diagnose renal tubular damage and assess the extent of the damage.

Retinoides (RARβ y CRBP1) en carcinoma de pulmón a células no pequeñas / Retinoid expression (RARβ and CRBP1) in non-small-cell lung carcinoma

Aunque los pacientes con cáncer de pulmón a células no pequeñas en estadios tempranos (NSCLC) tienen buen pronóstico, el 20-30% recae, siendo relevante la identificación de biomarcadores pronósticos. Los retinoides regulan crecimiento y diferenciación, y pueden antagonizar la progresión tumoral. Su efecto depende del transporte citosólico mediado por moléculas como CRBP1, y de la unión a receptores específicos (RARβ). Alteraciones en esta vía se asociaron con cáncer. Nuestro objetivo fue estudiar la expresión, mediante inmunohistoquímica, de RARβ y CRBP1 en el tejido tumoral de 49 pacientes NSCLC Estadio I/II, obtenido durante la cirugía. La supervivencia se analizó mediante los test Log Rank y multivariado de Cox. El 44.9% de los tumores fueron positivos para RARβ con expresión a nivel citoplasmático, mientras que el 34.7% lo expresó a nivel nuclear. La tinción para CRBP1 se observó en el 61.2% de los tumores. No se encontró asociación entre la expresión de ambas moléculas y las características clinicopatológicas (sexo, tamaño tumoral, nódulos línfáticos comprometidos, histopatología y p53). Tampoco se encontró asociación con el hábito de fu-mar. La presencia de células tumorales en el lavado pleural se asoció significativamente con la expresión de CRBP1. Por otro lado, se demostró asociación entre la expresión elevada de RARβ citoplasmático y menor supervivencia global (LR 4.17, p=0.0412). El análisis multivariado no mostró asociación con otras variables de pronóstico en NSCLC. En conclusión, en este grupo de pacientes NSCLC Estadio I/II, RARβ pareciera predecir la supervivencia global en forma independiente.

Although early-stage non-small-cell lung carcinoma (NSCLC) patients have a relative by favorable prognosis, the risk of a bad outcome remains substantial. Identification of reliable prognostic markers for disease recurrence and death has meaningful clinical application. Retinoids are involved in cell growth and differentiation and may antagonize cancer progression. Their effects are mediated through nuclear receptors called Retinoic Acid Receptor (RAR) and regulated by molecules such as Cellular Retinol-Binding Protein 1 (CRBP1) that function in retinol storage. The aim of this work was to analyze by immunohistochemistry the expression patterns of RARβ and CRBP1, involved in retinoid-mediated signaling, in the tumoral tissue of a cohort of stage I/II NSCLC patients (n=49) who underwent a successful surgical resection. Prognostic evaluation was performed with the multivariate Cox proportional hazard model: 44.9% of tumors were positive for RARβ staining at cytoplasmic level, while 34.7% showed nuclear staining. CRBP1 staining was observed in 61.2% of the lung tumors. No relationship was found between the number of cells expressing the studied molecules and clinical pathological features, including sex, T and N (stage), histopathology and p53 expression. Univariate analysis showed a significant association between positive cytoplasmatic expression of RARβ with shorter overall survival (Log-rank test 4.17, p=0.0412). Multivariate studies indicated that RARβ expression was not influenced by other clinical pathological parameters. In conclusion, in this cohort of stage I and II NSCLC, only the expression of RARβ at cytoplasmatic level is a significant independent unfavorable prognostic factor.

Effect and Catabolism of All-trans Retinoic Acid in Head and Neck Squamous Cell Carcinoma / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: All-trans retinoic acid (RA) is a form of vitamin A analogue that has shown chemopreventive activities in many types of malignancy with the properties that regulate cellular differentiations and suppress malignant proliferations. It is thought that the catabolism of RA is mediated by cytochrome P450RAI (CYP26) and its absorption, effects and catabolism are related to cellular retinol binding proteins (CRBP-I and II) and cellular retinoic acid binding proteins (CRABP-I and II). With eight different squamous cell carcinoma cell lines (AMC-HN-1~-8), we investigated the effects of RA and roles of these proteins in the metabolism and regulatory activity of RA. MATERIALS AND METHODS: Survival fractions of eight AMC-HN cells were analyzed six days after the treating them with 1 nM of RA. Reverse transcription-polymerase chain reactions (RT-PCR) were performed before and 24 hours after the load of 1 nM of RA to detect the expressions of CRBP-I, CRABP-I, CRABP-II, and CYP26. RESULTS: Resistances to RA were detected in AMC-HN-1, -2, -5, and -6 cell lines after RA treatment, and AMC-HN-3, -4, -7, and -8 cell lines showed sensitive responses to RA. Before the addition of RA, expressions of CYP26 were detected in AMC-HN-1, -2, -4, -5, -6, and -7 cell lines and CRBP-I was expressed in AMC-HN-3, 4, 5, 7, and -8. After RA addition, the expressions of CYP26 were enhanced in AMC-HN-2, -5, -6, and -7. In six of eight cell lines, CRABP-I was suppressed and CRABP-II was enhanced after RA treatment. CONCLUSION: These results suggest that CYP26 has a direct correlation with the cellular metabolism of RA in the head and neck squamous cell carcinomas and that CRABP-I and CRABP-II have distinct roles in the regulatory effects of RA. CRBP-I might be an indicator that implies the responsiveness to RA.