[Effect of curcumin on radiosensitization of CNE-2 cells and its mechanism].

OBJECTIVE: To investigate the effect of curcumin (Cur) on radiosensitivity of nasopharyngeal carcinoma cell CNE-2 and its mechanism. METHOD: The effect of curcumin on radiosensitivity was determined by the clone formation assay. The cell survival curve was fitted by Graph prism 6. 0. The changes in cell cycle were analyzed by flow cytometry (FCM). The differential expression of long non-coding RNA was detected by gene chip technology. Part of differentially expressed genes was verified by Real-time PCR. RESULT: After 10 micro mol L-1 Cur had worked for 24 h, its sensitization enhancement ratio was 1. 03, indicating that low concentration of curcumin could increase the radiosensitivity of nasopharyngeal carcinoma cells; FCM displayed a significant increase of G2 phase cells and significant decrease of S phase cells in the Cur combined radiation group. In the Cur group, the GUCY2GP, H2BFXP, LINC00623 IncRNA were significantly up-regulated and ZRANB2-AS2 LOC100506835, FLJ36000 IncRNA were significantly down-regulated. CONCLUSION: Cur has radiosensitizing effect on human nasopharyngeal carcinoma CNE-2 cells. Its mechanism may be related to the changes in the cell cycle distribution and the expression of long non-coding IncRNA.

A miR-151 binding site polymorphism in the 3'-untranslated region of the cyclin E1 gene associated with nasopharyngeal carcinoma.

Genetic alterations in nasopharyngeal carcinoma (NPC) have been reported in previous works. However, it remains unclear whether polymorphisms within the miRNA-target binding sites are associated with individual NPC risk. In this study, new experimental and computational approaches were developed to assess the polymorphism frequency distribution within the miRNA sites in NPC patients, and to explore its association with NPC risk. We focused on 220 single-nucleotide polymorphisms (SNPs) in the 3'-untranslated regions (3'UTRs) of 32 genes carrying putative miRNA-binding sites by specialized algorithms. A total of 9 candidate genes were selected for further investigation, which were reportedly overexpressed in NPC, including EGFR, COX2, CCNE1, hTERT, MMP2, MMP9, NF-κB VEGF, and WNT3. SNPs in 3'UTRs were genotyped by direct polymerase chain reaction sequencing of the genomic DNA of 24 cases and 24 controls. Then, EGFR rs884225, CCNE1 rs3218073, and MMP2 rs7201 were screened with large samples. Based on the analysis of a series of 167 NPC cases and 171 controls from Guangdong Province, statistically significant associations were found between NPC risk and variant genotypes of CCNE1 rs3218073 for TC+TT (OR=1.585; 95% CI=1.023-2.458; P=0.046) and for T-allele (OR=1.464; 95% CI=1.012-2.118; P=0.042). In addition, a significant association among rs3218073 genotype TC (OR=1.959, P=0.043), T-allele (OR=2.123, P=0.006), and primary tumor (T3-T4) was retrieved. Genotype TC (OR=1.959, P=0.043) and T-allele (OR=2.123, P=0.006) of rs3218073 were correlated with increased risk of higher NPC stage (III to IV). In support of the postulation that the 3'UTR SNP directly affected miRNA-binding site, luciferase reporter assay indicated that CCNE1 was a direct target of miR-151, and the rs3218073 T>C change resulted in altered regulation of CCNE1 expression. By contrast, no statistically significant association with NPC risk was found for MMP2 rs7201 and EGFR rs884225 polymorphisms (P>0.05). In conclusion, our data demonstrate that CCNE1 rs3218073 polymorphism located at miRNA-151 binding site is associated with NPC susceptibility and is correlated with NPC stage. These results suggest that CCNE1 rs3218073 polymorphism can be exploited as a novel biomarker for future NPC diagnosis and prognosis.

Serum KIAA1199 is an advanced-stage prognostic biomarker and metastatic oncogene in cholangiocarcinoma.

BACKGROUND: Cell proliferation and migration are the determinants of malignant tumor progression, and a better understanding of related genes will lead to the identification of new targets aimed at preventing the spread of cancer. Some studies have shown that KIAA1199 (CEMIP) is a transmembrane protein expressed in many types of noncancerous cells and cancer cells. However, the potential role of KIAA1199 in the progression of cholangiocarcinoma (CCA) remains unclear. RESULTS: Analysis of cancer-related databases showed that KIAA1199 is overexpressed in CCA. ELISA, immunohistochemistry, Western blotting and qPCR indicated high expression levels of KIAA1199 in serum, CCA tissues and CCA cell lines. In the serum (n = 41) and large sample validation (n = 177) cohorts, higher KIAA1199 expression was associated with shorter overall survival and disease-free survival times. At the cellular level, KIAA1199 overexpression (OE) promoted CCA growth and metastasis. Subcutaneous tumor xenograft experiments showed that KIAA1199 enhances CCA cell proliferation. Additionally, the expression levels of components in the EMT-related TGF-ß pathway changed significantly after KIAA1199 upregulation and silencing. CONCLUSION: KIAA1199 is a promising new diagnostic molecule and therapeutic target in CCA. The serum KIAA1199 level can be used as a promising clinical tool for predicting the overall postoperative outcomes of patients with CCA. METHODS: CCA-related KIAA1199 data were downloaded from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. To assess the prognostic impact of KIAA1199, an enzyme-linked immunosorbent assay (ELISA) was used to measure the serum level of KIAA1199 in 41 patients who underwent surgical resection. Immunohistochemical staining, Western blotting and qPCR were used to verify and retrospectively review the expression levels of KIAA1199 in cancer tissue specimens from 177 CCA patients. The effect of KIAA1199 on CCA was evaluated by cell-based functional assays and subcutaneous tumor xenograft experiments. The expression levels of proteins associated with epithelial-mesenchymal transition (EMT) and activation of relevant signaling pathways were measured via Western blotting.

MiR-593 mediates curcumin-induced radiosensitization of nasopharyngeal carcinoma cells via MDR1.

Curcumin (Cur) exhibits radiosensitization effects to a variety of malignant tumors. The present study investigates the radiosensitizing effect of Cur on nasopharyngeal carcinoma (NPC) cells and whether its mechanism is associated with microRNA-593 (miR-593) and multidrug resistance gene 1 (MDR1). A clonogenic assay was performed to measure the radiosensitizing effect. The expression of miR-593 and MDR1 was analyzed by quantitative polymerase chain reaction (qPCR) or western blot assay. A transplanted tumor model was established to identify the radiosensitizing effect in vivo. A luciferase-based reporter was constructed to evaluate the effect of direct binding of miR-593 to the putative target site on the 3' UTR of MDR1. The clonogenic assay showed that Cur enhanced the radiosensitivity of cells. Cur (100 mg/kg) combined with 4 Gy irradiation inhibited the growth of a transplanted tumor model in vivo, resulting in the higher inhibition ratio compared with the radiotherapy-alone group. These results demonstrated that Cur had a radiosensitizing effect on NPC cells in vivo and in vitro; Cur-mediated upregulation of miR-593 resulted in reduced MDR1 expression, which may promote radiosensitivity of NPC cells.

Curcumin enhances the radiosensitivity in nasopharyngeal carcinoma cells involving the reversal of differentially expressed long non-coding RNAs.

Long non-coding RNAs (lncRNAs) are aberrantly expressed and have important functions in pathological processes. The present study investigated the lncRNA profiles and the effects of curcumin (Cur) on the radiosensitivity of nasopharyngeal carcinoma (NPC) cells. The lncRNA and mRNA profiles of each cell group were described by microarray analysis. Numerous differentially expressed genes were observed by microarrays in three cell groups. Cur significantly reversed the IR-induced lncRNA and mRNA expression signatures, shown by clustering analysis. Moreover, 116 of these IR-induced and Cur-reversed differentially expressed lncRNAs were obtained. Six lncRNAs (AF086415, AK095147, RP1-179N16.3, MUDENG, AK056098 and AK294004) were confirmed by qPCR. Furthermore, functional studies showed that lncRNA AK294004 exhibited a negative effect on cyclin D1 (CCND1), indicating that CCND1 might be a direct target of AK294004. IR-induced differentially expressed lncRNAs were reversed during Cur-enhanced radiosensitization in NPC cells, suggesting that lncRNAs have important functions in IR-induced radioresistance. Thus, Cur could serve as a good radiosensitizer.