Therapeutic Vaccines Against Human Papillomavirus and Cervical Cancer

Cervical cancer and its precursor intra-epithelial lesions are linked to infection by a subset of so-called “highrisk” human papillomavirus types, which are estimated to infect nearly four hundred million women worldwide. Two prophylactic vaccines have been commercialized recently targeting HPV16 and 18, the most prevalent viral types found in cervical cancer, which operate through induction of capsid-specific neutralizing antibodies. However, in patients with persistent infection these vaccines have not been found to protect against progression to neoplasia. Attempts are being made to develop therapeutic vaccines targeting nonstructural early viral proteins. Among these, E6 and E7 are the preferred targets, since they are essential for induction and maintenance of the malignant phenotype and are constitutively expressed by the transformed epithelial cells. Here are reviewed the most relevant potential vaccines based on HPV early antigens that have shown efficacy in preclinical models and that are being tested in clinical studies, which should determine their therapeutic capacity for eradicating HPV-induced premalignant and malignant lesions and cure cervical cancer

DNA methylation pattern in high-grade cervical intraepithelial neoplasia and cancer revealed by genomewide methylation analysis of cervical DNA

Cancer of the uterine cervix is caused by a subset of oncogenic human Papillomavirus (HPV)-types with mucosal tropism. Besides the known effects of the viral oncoproteins on cellular functions there is evidence suggesting that cervical carcinogenesis involves epigenetic changes in the host DNA. In this study, we have examined the global promoter methylation profile associated with progression to cervical cancer at wide genome scale. The methylation pattern of nearly 14,000 genes was analyzed in cervical swabs at different stages of cervical carcinogenesis: low-grade cervical intraepithelial neoplasia (CIN I and II), high-grade CIN (CIN III) and invasive cancer, as well as healthy individuals. Unsupervised analysis (Hierarchical Clustering) identified two groups: A) healthy, CIN I and CIN II; and B) CIN III/cancer. Supervised T-Test analysis showed 1069 promoter regions hypermethylated and 85 hypomethylated in CIN III/cancer compared to CIN I/CIN II and healthy samples (p<0.0001). Overall, the differentially methylated genes act in transcription, cell cycle, apoptosis and cell adhesion pathways. Of the hypermethylated genes, 132 (12.3%) were down-regulated in a matched cervical cancer group. In turn, only 4 (4.7%) of the hypomethylated genes were overexpressed in that group.Centro de Investigaciones Inmunológicas Básicas y Aplicada

Heparin (GAG-hed) inhibits LCR activity of Human Papillomavirus type 18 by decreasing AP1 binding

BACKGROUND: High risk HPVs are causative agents of anogenital cancers. Viral E6 and E7 genes are continuously expressed and are largely responsible for the oncogenic activity of these viruses. Transcription of the E6 and E7 genes is controlled by the viral Long Control Region (LCR), plus several cellular transcription factors including AP1 and the viral protein E2. Within the LCR, the binding and activity of the transcription factor AP1 represents a key regulatory event in maintaining E6/E7 gene expression and uncontrolled cell proliferation. Glycosaminoglycans (GAGs), such as heparin, can inhibit tumour growth; they have also shown antiviral effects and inhibition of AP1 transcriptional activity. The purpose of this study was to test the heparinoid GAG-hed, as a possible antiviral and antitumoral agent in an HPV18 positive HeLa cell line. METHODS: Using in vivo and in vitro approaches we tested GAG-hed effects on HeLa tumour cell growth, cell proliferation and on the expression of HPV18 E6/E7 oncogenes. GAG-hed effects on AP1 binding to HPV18-LCR-DNA were tested by EMSA. RESULTS: We were able to record the antitumoral effect of GAG-hed in vivo by using as a model tumours induced by injection of HeLa cells into athymic female mice. The antiviral effect of GAG-hed resulted in the inhibition of LCR activity and, consequently, the inhibition of E6 and E7 transcription. A specific diminishing of cell proliferation rates was observed in HeLa but not in HPV-free colorectal adenocarcinoma cells. Treated HeLa cells did not undergo apoptosis but the percentage of cells in G(2)/M phase of the cell cycle was increased. We also detected that GAG-hed prevents the binding of the transcription factor AP1 to the LCR. CONCLUSION: Direct interaction of GAG-hed with the components of the AP1 complex and subsequent interference with its ability to correctly bind specific sites within the viral LCR may contribute to the inhibition of E6/E7 transcription and cell proliferation. Our data suggest that GAG-hed could have antitumoral and antiviral activity mainly by inhibiting AP1 binding to the HPV18-LCR

Highly Sensitive Detection and Genotyping of HPV by PCR Multiplex and Luminex Technology in a Cohort of Colombian Women with Abnormal Cytology

Cancer of the uterine cervix (CC) is the second most common cancer in women worldwide. In Colombia, CC is the second most frequent cancer among the entire women population and the first among women aged between 15 and 44 years, with an estimated incidence of 24.9 cases/100,000 inhabitants. The main risk factor is infection with one or more high-risk human papillomavirus (HPV) types. The aim of this study was to estimate the genotype-specific prevalence of human papillomavirus (HPV) DNA in patients with cervical pathology using the multiplex PCR and Luminex xMAP technology. In addition, we compared genotyping with Luminex xMAP and with Reverse Line Blot (RLB). A cohort of 160 patients participated in the study, of which 25.6% had no cervical lesions, 35% presented cervical intraepithelial neoplasia of grade I (CIN I), 10% CIN II, 20.6% CIN III and 8.8% CC. The most frequent viral types in all lesion grades were HPV16 and HPV18. Infections by a unique virus were less frequent (19.4%) than multiple infections (80.6%). Single infections were found in 22% of women with no cervical lesions, and in 14.3% of CIN I, 18.7% CIN II, 21.2% CIN III and 28.6% of CC. Multiple infections were observed in 78.0% of cervical samples with negative histopathologic diagnosis, and in 85.7% of CIN I, 81.2% CIN II, 78.8% CIN III and 71.4% CC. All samples analyzed with Luminex xMAP were HPV-positive, while we could detect HPV in only 48.8% of cases with RLB. Of the samples positive by both methods, there was a 67.2% correlation in the viral type(s) detected. In conclusion, Luminex suspension array showed a remarkably higher sensitivity compared with RLB. Multiple infections were unexpectedly common, being HPV types 16 and 18 the most prevalent in all histopathologic grades

Expresión de EDNRB y CDX2 posibles biomarcadores en progresión al cáncer cervical

De acuerdo a la historia natural del cáncer del cuello uterino, en donde las lesiones preneoplásicas de bajo y alto grado pueden presentar fenómenos de regresión o progresión, existe gran interés en la búsqueda de biomarcadores que permita predecir la evolución de las lesiones preneoplásicas del cérvix hacia la progresión o regresión de la enfermedad. Estos biomarcadores pudieran ser de origen genético, o epigenético que alteren la expresión de los genes y que pudieran estar asociados con la carcinogénesis en diferentes tipos de tejido humano. El objetivo del estudio fue analizar la expresión del mARN de los genes SFRP1, PTPRN, CDO1, EDNRB, CDX2, EPB41L3 y HAND1 en muestras negativas para lesiones intraepiteliales cervicales (n=9), muestras con lesiones intraepiteliales de bajo grado (n=10) y alto grado (n=11). Se realizó  análisis de expresión de los genes mencionados mediante qRT-PCR y el análisis de los datos se realizó mediante la prueba no paramétrica de ANOVA. La diferencia estadística se determinó en valores p 0,05. Para los genes EDNRB y CDX2 se observó disminución 66,7% en las muestras sin alteraciones histológicas cervicales, comparado con una disminución en la expresión del 50% en muestras con LIEBG y para el grupo de LIEAG del 36,4% para el gen EDNRB y del 27,3% para el gen CDX2 dando una diferencia estadísticamente significativa p= 0,02. Sugiriendo que EDNRB y CDX2 podrían ser útiles como posibles biomarcadores en la carcinogénesis cervical.According into account the natural history of cervical cancer, where low- and high-grade preneoplastic lesions may present regression or progression phenomena, there is great interest in the search for biomarkers to predict the behavior of preneoplastic lesions of the cervix. These biomarkers may be of genetic origin, or epigenetics that alter the expression of genes and that may be associated with carcinogenesis in different types of human tissue. The objective of the study was to analyze the expression of the mRNA of the SFRP1, PTPRN, CDO1, EDNRB, CDX2, EPB41L3 and HAND1 genes in samples negative for cervical intraepithelial lesions (n = 9), low grade intraepithelial lesions (n=10) and high grade (n = 11). Expression analysis of the mentioned genes was performed using qRT-PCR and data analysis was performed using the non-parametric ANOVA test. The statistical difference was determined in values p 0.05. For the EDNRB and CDX2 genes, a 66.7% decrease was observed in the samples without cervical histological alterations, compared to a decrease in expression of 50% in LIEBG samples and 36.4% in the LIEAG group for the EDNRB gene And 27.3% for the CDX2 gene giving a statistically significant difference p = 0.02. Suggesting that EDNRB and CDX2 could be useful as potential biomarkers in cervical carcinogenesis

Activating Natural Killer Cell Receptors, Selectins, and Inhibitory Siglecs Recognize Ebolavirus Glycoprotein

Expression of the extensively glycosylated Ebolavirus glycoprotein (EBOV-GP) induces physical alterations of surface molecules and plays a crucial role in viral pathogenicity. Here we investigate the interactions of EBOV-GP with host surface molecules using purified EBOV-GP, EBOV-GP-transfected cell lines, and EBOV-GP-pseudotyped lentiviral particles. Subsequently, we wanted to examine which receptors are involved in this recognition by binding studies to cells transfected with the EBOV-GP as well as to recombinant soluble EBOV-GP. As the viral components can also bind to inhibitory receptors of immune cells (e.g., Siglecs, TIM-1), they can even suppress the activity of immune effector cells. Our data show that natural killer (NK) cell receptors NKp44 and NKp46, selectins (CD62E/P/L), the host factors DC-SIGNR/DC-SIGN, and inhibitory Siglecs function as receptors for EBOV-GP. Our results show also moderate to strong avidity of homing receptors (P-, L-, and E-selectin) and DC-SIGNR/DC-SIGN to purified EBOV-GP, to cells transfected with EBOV-GP, as well as to the envelope of a pseudotyped lentiviral vector carrying the EBOV-GP. The concomitant activation and inhibition of the immune system exemplifies the evolutionary antagonism between the immune system and pathogens. Altogether these interactions with activating and inhibitory receptors result in a reduced NK cell-mediated lysis of EBOV-GP-expressing cells. Modulation of these interactions may provide new strategies for treating infections caused by this virus.publishedVersio

Prognostic value of inhibitors of apoptosis proteins (IAPs) and caspases in prostate cancer: caspase-3 forms and XIAP predict biochemical progression after radical prostatectomy

Background: The expression status of apoptotic regulators, such as caspases and inhibitors of apoptosis proteins (IAPs), could reflect the aggressiveness of tumors and, therefore, could be useful as prognostic markers. We explored the associations between tumor expression of caspases and IAPs and clinicopathological features of prostate cancer – clinical and pathological T stage, Gleason score, preoperative serum PSA levels, perineural invasion, lymph node involvement, surgical margin status and overall survival – and evaluated its capability to predict biochemical progression after radical prostatectomy. Methods: Protein expression of caspases (procaspase-8, cleaved caspase-8, procaspase-3, cleaved caspase-3, caspase-7 and procaspase-9) and IAPs (cIAP1/2, cIAP2, NAIP, Survivin and XIAP) was analyzed by immunohistochemistry in radical prostatectomy samples from 84 prostate cancer patients. Spearman’s test, Kaplan-Meier curves, and univariate and multivariate Cox proportional hazard regression analysis were performed. Results: cIAP1/2, cIAP2, Survivin, procaspase-8, cleaved caspase-8, procaspase-3 and caspase-7 expression correlated with at least one clinicopathological feature of the disease. Patients negative for XIAP, procaspase-3 or cleaved caspase-3 had a significantly worse prognosis. Of note, XIAP, procaspase-3 and cleaved caspase-3 were predictors of biochemical progression independent of Gleason score and pathological T stage. Conclusions: Our results indicate that alterations in the expression of IAPs and caspases contribute to the malignant behavior of prostate tumors and suggest that tumor expression of XIAP, procaspase-3 and cleaved caspase-3 may help to identify prostate cancer patients at risk of progression

MHC class I-related chain A and B ligands are differentially expressed in human cervical cancer cell lines

<p>Abstract</p> <p>Background</p> <p>Natural killer (NK) cells are an important resource of the innate immune system directly involved in the spontaneous recognition and lysis of virus-infected and tumor cells. An exquisite balance of inhibitory and activating receptors tightly controls the NK cell activity. At present, one of the best-characterized activating receptors is NKG2D, which promotes the NK-mediated lysis of target cells by binding to a family of cell surface ligands encoded by the MHC class I chain-related (MIC) genes, among others. The goal of this study was to describe the expression pattern of MICA and MICB at the molecular and cellular levels in human cervical cancer cell lines infected or not with human papillomavirus, as well as in a non-tumorigenic keratinocyte cell line.</p> <p>Results</p> <p>Here we show that MICA and MICB exhibit differential expression patterns among HPV-infected (SiHa and HeLa) and non-infected cell lines (C33-A, a tumor cell line, and HaCaT, an immortalized keratinocyte cell line). Cell surface expression of MICA was higher than cell surface expression of MICB in the HPV-positive cell lines; in contrast, HPV-negative cells expressed lower levels of MICA. Interestingly, the MICA levels observed in C33-A cells were overcome by significantly higher MICB expression. Also, all cell lines released higher amounts of soluble MICB than of soluble MICA into the cell culture supernatant, although this was most pronounced in C33-A cells. Additionally, Real-Time PCR analysis demonstrated that MICA was strongly upregulated after genotoxic stress.</p> <p>Conclusions</p> <p>This study provides evidence that even when MICA and MICB share a high degree of homology at both genomic and protein levels, differential regulation of their expression and cell surface appearance might be occurring in cervical cancer-derived cells.</p

CRPV Genomes with Synonymous Codon Optimizations in the CRPV E7 Gene Show Phenotypic Differences in Growth and Altered Immunity upon E7 Vaccination

Papillomaviruses use rare codons relative to their hosts. Recent studies have demonstrated that synonymous codon changes in viral genes can lead to increased protein production when the codons are matched to those of cells in which the protein is being expressed. We theorized that the immunogenicity of the virus would be enhanced by matching codons of selected viral genes to those of the host. We report here that synonymous codon changes in the E7 oncogene are tolerated in the context of the cottontail rabbit papillomavirus (CRPV) genome. Papilloma growth rates differ depending upon the changes made indicating that synonymous codons are not necessarily neutral. Immunization with wild type E7 DNA yielded significant protection from subsequent challenge by both wild type and codon-modified genomes. The reduction in growth was most dramatic with the genome containing the greatest number of synonymous codon changes