A wapl a day keeps the sisters apart: wapl and cohesin dynamics

Expression of various types of alternatively spliced WAPL transcripts in human cervical epithelia

We have previously identified a novel gene WAPL that is inducible by human papillomavirus (HPV) E6 and E7 oncoproteins, and is associated with uterine cervical carcinogenesis. A WAPL splice variant named Friend of EBNA2 (FOE) has also been characterized as a binding partner of the Epstein-Barr virus transformation-related protein EBNA2. On the other hand, recent studies have revealed that WAPL is a cohesin-binding protein and promotes sister-chromatid resolution in mitotic prophase. These data demonstrate that WAPL plays an important role in tumorigenesis and cell cycle progression. In this study, we have isolated a large number of additional alternatively spliced WAPL variants from various cervical epithelia. Each variant consists of a variable 5'-terminal region and the conserved remainder. In addition, we have confirmed the genomic organization of the 5'-region of the WAPL gene, and have investigated the characteristic features of the WAPL variants and their products. Furthermore, we have determined the HPV types of the expressed E6/E7 transcripts in the cervical epithelia with a novel PCR protocol. These results should shed light on a novel aspect of WAPL function.

Immunization of mice with plasmids coexpressing HPV16 E5 and the novel oncogene hWAPL

The novel human oncogene hWAPL is associated with uterine cervical cancer. The HPV16 E5 oncoprotein could induce genomic instability in normal human cells. However, the mechanism of E5 interaction with hWAPL still awaits definition. In our present studies, the eukaryotic expression plasmids, pcDNA3-hWAPL and pcDNA3-hWAPL-E5 were constructed and carried out to vaccinate mice directly. The result that indicated the polyclonal antibody titer in immunized mice sera was increased by enzyme-linked immunosorbent assay. In addition, the proliferative responses of immunized mice spleen cells showed the optical densities values in vaccinated group remarkably higher than that in the control group. In conclusion, the recombinant plasmids could induce strong humoral and cellular immune response and exhibited great potential as therapeutic targets in the treatment of cervical cancer. However, the result didn't show significant difference in group with coexpression of HPV16 E5-hWAPL and group with only hWAPL expression. Consistent with these observations, we demonstrated that HPV16 E5 was not the optimal factor to cooperate with hWAPL in gene therapy.