Human papillomavirus vaccine and cervical cancer prevention

Immunization with a poly (lactide co-glycolide) encapsulated plasmid DNA expressing antigenic regions of HPV 16 and 18 results in an increase in the precursor frequency of T cells that respond to epitopes from HPV 16, 18, 6 and 11

A phase II trial was conducted in subjects with human papillomavirus (HPV) associated high-grade cervical dysplasia testing the safety and efficacy of a microparticle encapsulated pDNA vaccine. Amolimogene expresses T cell epitopes from E6 and E7 proteins of HPV types 16 and 18. An analysis was performed on a subset of HLA-A2+ subjects to test whether CD8+ T cells specific to HPV 16, 18, 6 and 11 were increased in response to amolimogene immunization. Of the 21 subjects receiving amolimogene, 11 had elevated CD8+ T cell responses to HPV 16 and/or 18 peptides and seven of these also had increases to corresponding HPV 6 and/or 11 peptides. In addition, T cells primed and expanded in vitro with an HPV 18 peptide demonstrated cross-reactivity to the corresponding HPV 11 peptide. These data demonstrate that treatment with amolimogene elicits T cell responses to HPV 16, 18, 6 and 11.

Overexpression of PIP5KL1 suppresses the growth of human cervical cancer cells in vitro and in vivo

PIP5KL1 (phosphatidylinositol-4-phosphate 5-kinase-like 1), the fourth member of PIP5Ks (phosphatidylinositol-4-phosphate 5-kinases) type I, acts as a scaffold for localization and activation of PIP5Ks, which in turn regulate numerous cellular processes. However, the role of PIP5KL1 in the development of human cancer is poorly studied. In this study, we established a stable clone of PIP5KL1 overexpressing human cervical cancer HeLa cells. RT-PCR (reverse transcription-polymerase chain reaction) and Western immunoblot analysis were performed to testify the mRNA and protein levels of PIP5KL1 in HeLa cells. The effect of PIP5KL1 overexpression on in vitro cell growth was assessed by measuring cell proliferation and migration. The athymic nude mouse model was used to examine the effects of PIP5KL1 on tumour growth in vivo. Stable transfection of PIP5KL1 induced a significant increase in expression of both mRNA and protein levels and consequent robust inhibition of proliferation (P<0.05) and migration (P<0.05) of HeLa cells. Overexpression of PIP5KL1 significantly suppressed the growth of HeLa xenograft tumours in the flanks of nude mice. Taken together, these studies indicate a functional negative correlation between elevated levels of PIP5KL1 and the development of human cervical cancer, suggesting that PIP5KL1 overexpression may suppress cervical cancer formation.