Effects of HPV-16 E5, E6 and E7 Proteins on Survival, Adhesion, Migration and Invasion of Trophoblastic Cells

in Carcinogenesis (2010), 31(3), 473-80

Amongst high-risk human papillomaviruses (HPV), HPV-16 infection is the most prevalent causative factor for cervical cancer. Beside other mucosal targets, HPV-16 was reported to infect the placenta and to ... [more ▼]

Amongst high-risk human papillomaviruses (HPV), HPV-16 infection is the most prevalent causative factor for cervical cancer. Beside other mucosal targets, HPV-16 was reported to infect the placenta and to replicate in trophoblastic cells. Since these cells share invasive properties of tumoral cells, they represent an ideal model to investigate several oncogenic processes. In the present work, we analyzed the impacts of HPV-16 E5, E6 and E7 oncoproteins on the trophoblastic model. Our results showed that E5 impaired the viability of trophoblastic and cervical cell lines but E6 and E7, favouring cell growth, neutralised the E5 cytotoxic effect. In addition, E5 decreased the adhesiveness of trophoblastic cells to the tissue culture plastic and to endometrial cells similarly as previously described for E6 and E7. E5 and E6 plus E7 increased also their migration and their invasive properties. Cells expressing HPV-16 early proteins under the control of the LCR endogenous promoter displayed growth advantage and were also more motile and invasive compared to control cells. Interestingly, the E-cadherin was down regulated in trophoblastic cells expressing E5, E6 and E7. NF-kB and AP-1 activities were also enhanced. In conclusion, HPV-16 early proteins enhanced trophoblastic growth and intensify the malignant phenotype by impairing cell adhesion leading to increased cellular motile and invasive properties. HPV-16 E5 participated, with E6 and E7, in these changes by impairing Ecadherin expression, a hallmark of malignant progression. [less ▲]

Reduction of brain metastases in plasminogen activator inhibitor-1-deficient mice with transgenic ocular tumors

in Carcinogenesis (2008), 29(11), 2236-2242

Plasminogen activator inhibitor-1 is known to play a paradoxical positive role in tumor angiogenesis, but its contribution to metastatic spread remains unclear. We studied the impact of PAI-1 deficiency ... [more ▼]

Plasminogen activator inhibitor-1 is known to play a paradoxical positive role in tumor angiogenesis, but its contribution to metastatic spread remains unclear. We studied the impact of PAI-1 deficiency in a transgenic mouse model of ocular tumors originating from retinal epithelial cells and leading to brain metastasis (TRP-1/SV40 Tag mice). PAI-1 deficiency did not affect primary tumor growth or vascularization, but was associated with a smaller number of brain metastases. Brain metastases were found to be differentially distributed between the two genotypes. PAI-1-deficient mice displayed mostly secondary foci expanding from local optic nerve infiltration, whereas wild-type animals displayed more disseminated nodules in the scissura and meningeal spaces. SuperArray GEArray analyses aiming to detect molecules potentially compensating for PAI-1 deficiency demonstrated an increase in fibroblast growth factor-1 (FGF-1) gene expression in primary tumors, which was confirmed by RT-PCR and western blotting. Our data provide the first evidence of a key role for PAI-1 in a spontaneous model of metastasis, and suggest that angiogenic factors, such as FGF-1, may be important for primary tumor growth and may compensate for the absence of PAI-1. They identify PAI-1 and FGF-1 as important targets for combined anti-tumor strategies. [less ▲]

Release of N2,3-ethanoguanine from haloethylnitrosourea-treated DNA by Escherichia coli 3-methyladenine DNA glycosylase II

in Carcinogenesis (1991), 12(10), 1971-1973

Development of monoclonal antibodies recognizing 7-(2-hydroxyethyl)guanine and imidazole ring-opened 7-(2-hydroxyethyl)guanine.

in Carcinogenesis (1990), 11

Release of the chloroethyl ethyl sulfide-modified DNA bases by bacterial 3-methyladenine DNA glycosylase I and II

in Carcinogenesis (1989), 10(3), 489-492