Regression of papilloma high-grade lesions (CIN 2 and CIN 3) is stimulated by therapeutic vaccination with MVA E2 recombinant vaccine

Tumor dormancy and the role of metastasis suppressor genes in regulating ectopic growth

Metastasis, or tumor growth in an ectopic site, may occur several years after apparently successful treatment of the primary malignancy. Clinical dormancy is seen in a large number of cancer patients, but once growth in an ectopic site initiates, current adjuvant therapies are inadequate and the majority of patients with metastatic disease will die. Many genes may regulate ectopic growth in a secondary site, including a small subset, termed the metastasis suppressor genes. Investigation into this class of genes holds promise in terms of gaining a greater understanding of tumor dormancy and how the process of metastasis may be naturally inhibited. This review will focus on the role of metastasis suppressor genes in tumor dormancy. Insights into the metastatic process from studies of metastasis suppressor genes may lead to novel targets for antimetastatic therapy through drug-induced reactivation of one or more of these genes and/or their respective signaling pathways.

Recent advances in human papillomavirus vaccines

The human papillomavirus (HPV) is one of the most common sexually transmitted infections and the etiologic agent of cervical dysplasia and cancer. Recent research on the safety and efficacy of prophylactic vaccines against HPV has shown promising results with nearly 100% efficacy in preventing persistent infections and cervical dysplasia. Several approaches are being tested in therapeutic vaccine clinical trials whereby E6, E7, or both agents are administered in live viral vectors, as proteins, or in nucleic acid form. Cell-based therapeutic vaccines are also being tested. HPV vaccines have the potential to eradicate a major cancer and source of morbidity around the world.

HLA class I binding promiscuity of the CD8 T-cell epitopes of human papillomavirus type 16 E6 protein

One of the critical steps in the progression to cervical cancer appears to be the establishment of persistent human papillomavirus (HPV) infection. We have demonstrated that the lack of cytotoxic T-lymphocyte response to HPV type 16 (HPV 16) E6 protein was associated with persistence and that the potential presence of dominant CD8 T-cell epitopes was most frequently found (n = 4 of 23) in the E6 16-40 region by examining the pattern of CD8 T-cell epitopes within the E6 protein in women who had cleared their HPV 16 infections. The goal of this study was to define the minimal/optimal amino acid sequences and the HLA restricting molecules of these dominant CD8 T-cell epitopes as well as those of subdominant ones if present. Three dominant epitopes, E6 29-38 (TIHDIILECV; restricted by the HLA-A0201 molecule), E6 29-37 (TIHDIILEC; restricted by B48), and E6 31-38 (HDIILECV; restricted by B4002), and one subdominant epitope, E6 52-61 (FAFRDLCIVY; restricted by B35) were characterized. Taken together with a previously described dominant epitope, E6 52-61 (FAFRDLCIVY; restricted by B57), the CD8 T-cell epitopes demonstrated striking HLA class I binding promiscuity. All of these epitopes were endogenously processed, but the presence of only two of the five epitopes could have been predicted based on the known binding motifs. The HLA class I promiscuity which has been described for human immunodeficiency virus may be more common than previously recognized.

[Anti human-papillomavirus vaccines: concepts, aims and trials]

PURPOSE

Human Papillomaviruses (HPV) are epitheliotropic for stratified malpighian epithelia such as those of the cervix. Among them, oncogenic viruses are detectable in 99.7% of cervical cancers. A great priority is to develop a vaccine either against primary infection (preventive vaccine) allowing protection against HPV infection or therapeutic vaccine in order to kill previously infected or transformed keratinocytes.

CURRENT KNOWLEDGE AND KEY POINTS

Preventive vaccines against HPV contain virus like particles (VLP) 16 and 18 and induce a high titer of blood anti-VLP antibodies. They were recently tested in humans and have shown true efficiency for the prevention of cervical cancer. The therapeutic vaccines are therefore currently being developed in order to increase anti-HPV natural CD4+ and CD8+ T-cell immunity in women infected during their sexual activity.

FUTURE PROSPECTS

The perspective of the prophylactic vaccines is to decrease both genital HPV infection and cervical cancer. The impact of preventive vaccine must be carefully analyzed in order to prevent collateral side effects. The therapeutic vaccines have also a future in women already infected by HPV and might have an efficiency similar to surgery in the treatment of cervical intraepithelial neoplasia.