C5orf66 rs4976270/rs639933 Are Associated with Colorectal Cancer Risk in Southern Chinese Han Population: A Case-Control Study.

BACKGROUND: Colorectal cancer (CRC) is one of the common malignant tumors, with high mortality and poor prognosis. Our study aimed to determine the association between the long noncoding RNA (LncRNA) C5orf66 polymorphism and CRC risk in southern Chinese Han population. METHOD: Using the experimental design of "case-control" study (512 cases and 513 controls), we selected 4 candidate single-nucleotide polymorphisms (SNPs) of C5orf66. All candidate SNPs were genotyped by Agena MassARRAY. Logistic regression was used to analyze the association between SNPs and CRC risk. Then, we used false-positive report probability analysis to detect whether the significant result is just a chance or noteworthy observation. Multi-factor dimensionality reduction was used to analyze the interaction of "SNP-SNP" in CRC risk. RESULTS: Our results showed that C5orf66 SNPs rs4976270 (odds ratio [OR] = 1.69, p = 0.021) and rs639933 (OR = 1.67, p = 0.024) were, respectively, associated with increasing CRC risk in the southern Chinese Han population. Stratified analysis showed that rs4976270 and rs639933 were significantly associated with an increased risk of CRC in subgroups (>60 years, body mass index ≤24 and drinking) under multiple genetic models. In addition, rs254563 and rs647161 also had potential association with CRC risk in subgroups (BMI ≤24 and drinking). Finally, haplotype analysis results showed that haplotype "TA" was significantly associated with increased CRC risk (OR = 1.21, confidence interval = 1.47-2.02, p = 0.043). CONCLUSION: Our study provides a new idea for the risk assessment of CRC. LncRNA C5orf66 SNPs have a certain association with CRC risk in the southern Chinese Han population.

The lysine at position 151 of the duck hepatitis A virus 1 2C protein is critical for its NTPase activities.

The duck hepatitis A virus 1 (DHAV-1) 2C protein was predicted to be a superfamily III helicase member and includes nucleotide binding (NTB) and putative RNA helicase activity motifs. To study whether DHAV-1 2C protein has NTB activity, we expressed DHAV-1 2C protein with maltose binding protein (MBP) to solve its poor solubility in a prokaryotic expression system. We showed that the DHAV-1 2C protein has nucleoside triphosphatase (NTPase) activity by measuring the released phosphate. The NTPase of the DHAV-1 2C protein is Mg2+ indispensable and affected by other biochemical characteristics such as Mn2+, Ca2+, Zn2+, Na+ and pH. Guanidine hydrochloride (GdnHCl), a potent inhibitor of viral RNA replication, inhibited ATPase activity of the DHAV-1 2C protein in a dose-dependent manner. Finally, we constructed three mutants to identify the key site for the ATPase activity of the DHAV-1 2C protein. These results indicate that lysine at position 151 of the DHAV-1 2C protein is very important for NTPase activity. Here, we demonstrated and partially characterized that the DHAV-1 2C protein has NTPase activity and showed that mutation of the lysine in the conserved Walker A impairs that activity. The results serve to confirm what is readily predicted from previous work on picornavirus 2C proteins. It also provides a basis for further study of the 2C protein and the function of NTPase activity on the viral life cycle.