Expression of Coiled-Coil Domain Containing 34 (CCDC34) and its Prognostic Significance in Pancreatic Adenocarcinoma

Polymorphisms in transcription factor binding sites and enhancer regions and pancreatic ductal adenocarcinoma risk

Genome-wide association studies (GWAS) are a powerful tool for detecting variants associated with complex traits and can help risk stratification and prevention strategies against pancreatic ductal adenocarcinoma (PDAC). However, the strict significance threshold commonly used makes it likely that many true risk loci are missed. Functional annotation of GWAS polymorphisms is a proven strategy to identify additional risk loci. We aimed to investigate single-nucleotide polymorphisms (SNP) in regulatory regions [transcription factor binding sites (TFBSs) and enhancers] that could change the expression profile of multiple genes they act upon and thereby modify PDAC risk. We analyzed a total of 12,636 PDAC cases and 43,443 controls from PanScan/PanC4 and the East Asian GWAS (discovery populations), and the PANDoRA consortium (replication population). We identified four associations that reached study-wide statistical significance in the overall meta-analysis: rs2472632(A) (enhancer variant, OR 1.10, 95%CI 1.06,1.13, p = 5.5 × 10-8), rs17358295(G) (enhancer variant, OR 1.16, 95%CI 1.10,1.22, p = 6.1 × 10-7), rs2232079(T) (TFBS variant, OR 0.88, 95%CI 0.83,0.93, p = 6.4 × 10-6) and rs10025845(A) (TFBS variant, OR 1.88, 95%CI 1.50,1.12, p = 1.32 × 10-5). The SNP with the most significant association, rs2472632, is located in an enhancer predicted to target the coiled-coil domain containing 34 oncogene. Our results provide new insights into genetic risk factors for PDAC by a focused analysis of polymorphisms in regulatory regions and demonstrating the usefulness of functional prioritization to identify loci associated with PDAC risk.

Up-Regulated CCDC34 Contributes to the Proliferation and Metastasis of Hepatocellular Carcinoma

Background

Coiled-coil domain-containing protein 34 (CCDC34), which belongs to the CCDCs family, has been recently reported to be up-regulated in various kinds of tumors. However, its role in the development of hepatocellular carcinoma (HCC) still remains unclear.

Materials and methods

In this study, real-time polymerase chain reaction (RT-PCR) and Western blot analysis were performed to measure the mRNA and protein levels of CCDC34 in clinical samples. Kaplan-Meier method was used to analyze the relationship between CCDC34 and the prognosis in HCC patients. CCK-8 and colony formation assays were conducted to investigate CCDC34's effect on the cell proliferation, and Transwell assays were used to detect CCDC34's effect on the cell metastasis. Moreover, subcutaneous xenograft tumor model and lung metastasis model were applied to confirm the impact of CCDC34 on the HCC development. Lastly, RNA sequencing and Western blot analysis were performed to probe the underlying mechanism of CCDC34's effect on HCC.

Results

CCDC34 was significantly induced in HCC tissues, and the overexpression of CCDC34 predicted the poor outcomes among HCC patients. It was verified by the in vitro and in vivo experiments that CCDC34-knockdown potently inhibited the proliferation and metastasis of HCC cells. Subsequent results indicated that CCDC34 inhibition can affect the activation of protein kinase B (PKB or AKT) as well as epithelial-mesenchymal transition (EMT) process.

Conclusion

CCDC34 is significantly associated with HCC. It will become a promising prognostic biomarker and therapeutic target against HCC.

Down-regulation of MiR-539 Indicates Poor Prognosis in Patients with Pancreatic Cancer

It has been demonstrated that miR-539 plays an important role in the development and progression of tumors. The purpose of this study was to analyze the correlation between the expression level of miR-539 and the clinicopathological features and prognosis of patients with pancreatic cancer. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze the expression level of miR-539 in 60 patients with pancreatic cancer. It was found that miR-539 gene expression was down-regulated in pancreatic cancer compared with that in paracancerous tissues. In addition, the expression level of miR-539 was inversely correlated with tumor differentiation (poorly to moderately differentiated vs. well differentiated, P=0.006), lymph node metastasis (positive vs. negative, P=0.006), clinical stage (III-IV vs. I-II, P=0.002), CA199 (≥200 vs. <200, P=0.019) and distant metastasis (positive vs. negative, P=0.035). The survival time of pancreatic cancer patients with low expression of miR-539 was significantly shorter than that of patients with high expression of miR-539. Multivariate analysis suggested that miR-539 expression level was an independent prognostic indicator for patients with pancreatic cancer (P=0.025). Down-regulation of miR-539 may be a potentially unfavorable prognostic factor for patients with pancreatic cancer, and further studies are needed to confirm our conclusion in the future.

High Expression of CCDC34 Is Associated with Poor Survival in Cervical Cancer Patients

BACKGROUND The present study explored the expression of coiled-coil domain-containing 34 (CCDC34) in cervical cancer (CC) and its prognostic value. MATERIAL AND METHODS GEPIA and Oncomine cancer databases were mined to predict the CCDC34 differential expression level between a CC group and a normal group. Immunohistochemistry was performed to examine the CCDC34 expression in 67 CC and corresponding adjacent tissues. CD31 and vascular endothelial growth factor (VEGF) were stained to reflect tumor angiogenesis in 67 CC tissues. Kaplan-Meier univariate and Cox multivariate survival analysis were done to evaluate the correlation between CCDC34 expression and prognosis of CC patients. RESULTS Both GEPIA and Oncomine cancer databases mining results revealed that CCDC34 was more highly expressed in the CC group than in the normal group (all P<0.05). Our immunochemical staining data showed that CCDC34 expression was dramatically higher in CC than in adjacent normal tissues (71.6 vs. 20.9%; P<0.001). High expression of CCDC34 was strongly associated with histological grade (P=0.022), lymph node metastasis (P=0.044), and FIGO stage (P=0.002). Furthermore, patients with CCDC34-positive expression had much more MVD than those with CCDC34-negative expression (P<0.001). Kaplan-Meier survival analysis showed that CCDC34-positive expression was associated with worse overall survival (OS) (P=0.004) and disease-free survival (DFS) (P=0.005). Additionally, Cox multivariate analysis revealed that CCDC34 was an independent unfavorable prognostic parameter of DFS and OS (P=0.040 and 0.039, respectively). CONCLUSIONS High expression of CCDC34 is an independent unfavorable prognostic parameter for OS and DFS of CC patients, which was strongly associated with tumor angiogenesis.