Background The oncogenic activity of the high risk human papillomavirus type 16 (HPV16) is fully dependent on the E6 and E7 viral oncoproteins produced during viral infection. The oncoproteins interfere with cellular homeostasis by promoting proliferation, inhibiting apoptosis and blocking epithelial differentiation, driving the infected cells towards neoplastic progression. The causal relationship between expression of E6/E7 and cellular transformation allows inhibiting the oncogenic process by hindering the activity of the two oncoproteins. We previously developed and characterized some antibodies in single-chain format (scFvs) against the HPV16 E6 and E7 proteins, and demonstrated both in vitro and in vivo their antitumor activity consisting of protective efficacy against tumor progression of HPV16-positive cells. Methods Envisioning clinical application of the best characterized anti-HPV16 E6 and –HPV16 E7 scFvs, we verified their activity in the therapeutic setting, on already implanted tumors. Recombinant plasmids expressing the anti-HPV16 E6 scFvI7 with nuclear targeting sequence, or the anti-HPV16 E7 scFv43M2 with endoplasmic reticulum targeting sequence were delivered by injection followed by electroporation to three different preclinical models using C57/BL6 mice, and their effect on tumor growth was investigated. In the first model, the HPV16+ TC-1 Luc cells were used to implant tumors in mice, and tumor growth was measured by luciferase activity; in the second model, a fourfold number of TC-1 cells was used to obtain more aggressively growing tumors; in the third model, the HPV16+ C3 cells where used to rise tumors in mice. To highlight the scFv possible mechanism of action, H&E and caspase-3 staining of tumor section were performed. Results We showed that both the anti-HPV16 E6 and HPV16 E7 scFvs tested were efficacious in delaying tumor progression in the three experimental models and that their antitumor activity seems to rely on driving tumor cells towards the apoptotic pathway. Conclusion Based on our study, two scFvs have been identified that could represent a safe and effective treatment for the therapy of HPV16-associated lesions. The mechanism underlying the scFv effectiveness appears to be leading cells towards death by apoptosis. Furthermore, the validity of electroporation, a methodology allowed for human treatment, to deliver scFvs to tumors was confirmed.

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A 47-year-old woman developed metastatic melanoma to the right ovary 14 years after the enucleation of the right eye for a choroidal spindle cell melanoma. An immunohistochemical study was performed on paraffin sections of both primary and metastatic melanoma specimens to identify markers of both aggressive phenotype and metastatic potential with particular attention to the anomalous expression of cytokeratin intermediate filament proteins. Neoplastic cells of both primary and metastatic tumors immunostained positively for S-100, HMB45, MART-1, and vimentin antibodies, but they were negative for cytokeratins 1-19, 8, 18, and 8,18; <10% of neoplastic cells in both the primary and the metastatic melanomas immunostained for Ki-67 proliferating antigen using MIB-1 antibody. We speculate that the indolent behavior of this ovarian metastasis is reflected by the absence of coexpression of cytokeratins 8 and 18 with vimentin. This case supports the practical value of using this panel of antibodies to evaluate the aggressive potential of uveal melanomas.Although the ovary is the site involved in 5 to 10% of metastases from various tumors, with the majority showing bilateral involvement, it is relatively uncommon to be involved by metastatic melanoma (1). However, ovarian metastases are present in 16 to 18% of women dying from malignant melanoma (2,3). Most melanomas metastatic to the ovary originate in the skin, but occasionally examples arise in the choroid (3).Choroidal melanoma constitutes the most common primary malignancy of the eye in adults (4); although it shows aggressiveness in some patients, it also shows a relative quiescence in others (5). For this reason, the study of prognostic markers indicative of the metastatic potential of choroidal melanoma would facilitate the identification of patients at risk for metastasis.The expression of vimentin and cytokeratins 8 and 18 in cutaneous melanoma was found to be associated with recurrent and metastatic disease (6-8). Hendrix and colleagues (9) found that human uveal melanoma cell lines showing coexpression of vimentin and cytokeratins 8 and 8,18 intermediate filaments were more invasive through the extracellular matrix than melanoma cells expressing only vimentin.We report a case of a melanoma metastatic to the right ovary in a 47-year-old woman who had removal of choroidal melanoma 14 years earlier. An immunohistochemical study was performed on paraffin sections of both primary and metastatic melanoma specimens to identify markers of both aggressive phenotype and metastatic potential, with particular attention to the expression of cytokeratin intermediate filament protein. We reviewed the literature of reported cases of malignant choroidal melanoma metastasizing to the ovary.

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