P53 inactivation by p53 mutation and E6 oncoprotein has a crucial role in human carcinogenesis. DDX3 has been shown to be a target of p53. In this study, we hypothesized that DDX3 loss by p53 inactivation may promote tumor malignancy and poor patients' outcome. Mechanically, DDX3 loss by p53 knockdown and E6 overexpression was observed in A549 lung cancer cells. Conversely, DDX3 expression was markedly elevated by wild-type (WT) p53 ectopic expression in p53-null H1299 cells, E6-knockdown TL-1 lung cancer and SiHa cervical cancer cells. Interestingly, DDX3 loss promotes soft-agar growth and invasive capability; however, both capabilities were suppressed by DDX3 overexpression. We next expected that DDX3 loss might result in Slug-suppressed E-cadherin expression via decreased MDM2-mediated Slug degradation. As expected, MDM2 transcription is suppressed by DDX3 loss via decreased SP1 binding activity to the MDM2 promoter. Consequently, Slug expression was elevated by the reduction of MDM2 because of DDX3 loss, and E-cadherin expression was suppressed by Slug. Consistent observations in the correlation of DDX3 loss with MDM2, Slug and E-cadherin were seen in lung tumors from lung cancer patients. In addition, patients with low-DDX3 tumors had poorer survival and relapse than patients with high-DDX3 tumors. In conclusion, we suggest that DDX3 loss by p53 inactivation via MDM2/Slug/E-cadherin pathway promotes tumor malignancy and poor patient outcome.

Second and third hepatectomies seem justified for hepatic recurrence of HCC. The role of fourth hepatectomy needs further investigation.

Noroviruses (NoVs) and sapoviruses (SaVs) of the family Caliciviridae are emerging enteric pathogens in humans and animals. Recent detection of genogroup II norovirus (GII NoV) RNA from swine raises public health concerns about zoonotic transmission of porcine NoVs to humans. However, few papers reported genotype distributions and epidemiological features in swine farms and their genetic relationship to human strains, which was the objective of our study. This study investigated the epidemiological features and genotypes of caliciviruses in swine farms using 533 pig faecal samples from six farms in central and southern Taiwan, tested for viral RNA using RT-PCR targeting the conserved polymerase gene. NoVs and SaVs were detected with a positive rate of 7.1% and 0.6%, respectively. To confirm the positive rate of NoVs, 255 pig faecal samples from two farms in central Taiwan were tested with primer pairs targeting the partial capsid gene of GII, and 32.3% of the positive rate was found. Furthermore, the results from the capsid region suggested a higher positive rate of 41.7% in winter than 26.4% in summer with statistical significance (P < 0.05). Sequence analysis showed 29 strains belonging to GII.4 (human) and nine strains belonging to GII.11 (swine) identified based on the partial polymerase gene. Additional genotypes clustered with GII.2 (human) and GII.18 (swine) were also characterized based on the partial capsid gene. SaVs detected in porcine faecal samples belonged to genogroup III (GIII), which clustered with the PEC-Cowden strain. Our study demonstrated the presence of multiple genotypes of both human and porcine NoVs infecting swine of various ages asymptomatically. Although the zoonotic potential of detected human NoVs in swine was not conclusive owing to the lack of local human faecal samples, our study revealed the importance of monitoring emerging strains in swine to mitigate the potential impact of recombinant NoVs infecting the human population.

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