The etiology of vulvar and vaginal squamous cell carcinoma (VV-SCC) has received little attention. A total of 182 women with invasive VV-SCC (116 with VV-SCC vulva , 66 with VV-SCC vagina ), 164 uterine corpus cancer controls and 518 population controls were interviewed in a population-based case-control study in Denmark, and 87 (48%) of the VV-SCC cases had tissue samples examined for human papillomavirus (HPV) DNA using the GP51/61 PCR-EIA assay and subsequent reverse line blotting for HPV typing. Logistic regression-derived odds ratios with 95% confidence intervals served as relative risks. Cervical cancer-associated high-risk HPVs (hrHPVs) were detectable in most (89%) examined cases of VV-SCC vagina and in half (50%) of cases of VV-SCC vulva (p < 0.001). In site-specific multivariate logistic regression analyses, statistically significant risk factors for both VV-SCC vulva and VV-SCC vagina included measures of hrHPV exposure (anogenital warts for VV-SCC vulva ; cervical neoplasia and poor genital hygiene for VV-SCC vagina ), tobacco smoking and alcohol consumption. Furthermore, socioeconomic variables (marital status and years at school) were associated with risk of VV-SCC vulva . Comparing hrHPV-positive and hrHPV-negative VV-SCCs in polytomous logistic regression analysis revealed that tobacco smoking and cervical neoplasia were significant risk factors only for hrHPV-positive VV-SCCs. Our study shows that VV-SCC vulva and VV-SCC vagina share measures of prior hrHPV exposure, tobacco smoking and alcohol consumption as statistically significant risk factors. HPV vaccination programs aimed at reducing the burden of cervical cancers are likely to also provide considerable protection against VV-SCCs.

Few etiologic studies of squamous cell carcinoma (SCC) of the penis have been carried out in populations where childhood circumcision is rare. A total of 71 patients with invasive (n = 53) or in situ (n = 18) penile SCC, 86 prostate cancer controls, and 103 population controls were interviewed in a population-based casecontrol study in Denmark. For 37 penile SCC patients, tissue samples were PCR examined for human papillomavirus (HPV) DNA. Overall, 65% of PCR-examined penile SCCs were high-risk HPV-positive, most of which (22 of 24; 92%) were due to HPV16. Penile SCC risk was positively associated with measures of early and high sexual activity, including lifetime number of female sex partners, number of female sex partners before age 20, age at first intercourse, penile-oral sex, a history of anogenital warts, and never having used condoms. Histories of phimosis and priapism at least 5 years before diagnosis were also significant risk factors, whereas alcohol abstinence was associated with reduced risk. Our study confirms sexually transmitted HPV16 infection and phimosis as major risk factors for penile SCC and suggests that penileoral sex may be an important means of viral transmission. The association with priapism was unexpected and needs replication. (Cancer Epidemiol Biomarkers Prev 2008;17(10):2683 -91)

No abstract

In this study, we characterize the molecular signal pathways that lead to MHC class I chain-related protein A (MICA) expression after histone deacetylase (HDAC)-inhibitor (HDAC-i) treatment of Jurkat T cells. Chelating calcium with BAPTA-AM or EGTA potently inhibited HDAC- and CMV-mediated MICA/B expression. It was further observed that endoplasmic reticulum calcium stores were depleted after HDAC treatment. NF-κB activity can be induced by HDAC treatment. However, nuclear translocation of NF-κB p65 was not observed after HDAC treatment of Jurkat T cells and even though we could effectively inhibit p65 expression by siRNA, it did not modify MICA/B expression. To identify important elements in MICA regulation, we made a promoter construct consisting of ∼3 kb of the proximal MICA promoter in front of GFP. Deletion analysis showed that a germinal center-box containing a putative Sp1 site from position −113 to −93 relative to the mRNA start site was important for HDAC and CMV-induced promoter activity. Sp1 was subsequently shown to be important, as targeted mutation of the Sp1 binding sequence or siRNA mediated down modulation of Sp1-inhibited MICA promoter activity and surface-expression.

NKG2D ligand surface expression is important for immune recognition of stressed and neotransformed cells. In this study, we show that surface expression of MICA/B and other NKG2D ligands is dependent on N-linked glycosylation. The inhibitor of glycolysis and N-linked glycosylation, 2-deoxy-d-glucose (2DG), potently inhibited surface expression of MICA/B after histone deacetylase inhibitor treatment; the inhibition occurred posttranscriptionally without affecting MICA promoter activity. Transient overexpression of MICA surface expression was also inhibited by 2DG. 2DG blocks N-linked glycosylation of MICA/B by a reversible mechanism that can be alleviated by addition of d-mannose; this does not, however, affect the inhibition of glycolysis. Addition of d-mannose restored MICA/B surface expression after 2DG treatment. In addition, specific pharmacological or small interfering RNA-mediated targeting of glycolytic enzymes did not affect MICA/B surface expression, strongly suggesting that N-linked glycosylation, and not glycolysis, is essential for MICA/B surface expression. Corroborating this, tunicamycin, a selective inhibitor of N-linked glycosylation, abolished MICA/B surface expression without compromising activation of MICA promoter activity. NK cell-mediated killing assay and staining with a recombinant NKG2D–Fc fusion protein showed that all functional NKG2D ligands induced by histone deacetylase inhibitor treatment were abolished by 2DG treatment and fully reconstituted by further addition of d-mannose. Our data suggest that posttranslational N-linked glycosylation is strictly required for NKG2D ligand surface expression. Cancer and infection often result in aberrant glycosylation, which could likely be involved in modulation of NKG2D ligand expression. Our data further imply that chemotherapeutic use of 2DG may restrict NKG2D ligand surface expression and inhibit secretion of immunoinhibitory soluble NKG2D ligands.