Angiogenesis modulators expression in culture cell lines positives for HPV-16 oncoproteins

Association between tumour necrosis factor-a polymorphism and cervical cancer in Lagos State, Nigeria

Background

The data on tumour necrosis factor-α (TNF-α) promoter gene polymorphism in the African population are relatively limited, especially in Nigerian women.

Objectives

This study aimed to determine the prevalence and allele distribution of three TNF-α promoter gene SNPs loci - rs361525 (-238 G>A), rs1799964(-1031 T>C) and rs1800629 (-308 G>A) in women with cervical cancer (CC) and then evaluated the association between TNF-α SNPs and CC among women in Lagos, Nigeria.

Methods

This is a cross-sectional study of 75 unmatched human immunodeficiency virus (HIV)-infected and uninfected women with and without CC enrolled from October 2021 to January 2023 at the gynaecological oncology, cytology, adult HIV and blood donor clinics of the Lagos University Teaching Hospital. About 5 mL of peripheral blood was collected from each participant for total Deoxyribonucleic acid extraction, primer synthesis and genotyping. The probability of developing CC based on the given SNP genotype was expressed as an odds ratio (OR) with a 95% confidence interval. Allelic frequency deviations from Hardy-Weinberg equilibrium were calculated using chi-square, and the statistical significance level was considered as two-tailed and set at p ≤ 0.05.

Results

Our study found that TNF-α -1031 T>C polymorphism was significantly associated with increased CC risk in HIV-negative women (HIV+/CC-; OR = 1.4, 95%CI 0.23-8.42, p = 0.03 and HIV-/CC-; OR = 1.37, 95%CI 0.01-1.68, p = 0.03) while the -308A>G A allele was also significantly associated with CC in HIV-positive women (OR = 1.33, 95%CI = 0.23-7.75).

Conclusion

We observed that HIV-negative and HIV-positive women who carry the C allele of -1031T>C and the A allele of -308G>A TNF-a promoter gene loci, respectively, are more susceptible to CC. We were also able to show protective linkages for the minor allele of the three SNPs of interest suggesting the potential of TNF-a as a surrogate marker for CC screening in addition to human papillomavirus primary testing. Further studies are required to determine the association between host factors and TNF-a polymorphism to harness the diagnostic and therapeutic advantage these associations will provide in the management of CC.

Current Status of Human Papillomavirus Infection and Cervical Cancer in the Philippines

Cervical cancer is estimated to cause 341,831 deaths each year, with 9 of 10 deaths occurring in developing countries. Over the past decade, there has been a significant increase in cervical cancer incidence among women in the Philippines. Persistent infection with high-risk human papillomavirus (HPV) is the well-established necessary cause of cervical cancer. Based on limited studies conducted in the Philippines, the prevalence of infection with any HPV genotype was 93.8% for cervical squamous cell carcinoma and 90.9% for cervical adenocarcinomas. HPV types 16 and 18 were the most common HPV genotypes among Filipino patients with cervical cancer. On the other hand, the incidence of HPV infection among Filipino women with normal cervices was 9.2%. The World Health Organization has launched a global agenda of eliminating HPV infection by 2030. One of its key milestones is to vaccinate 90% of girls with the HPV vaccine by 15 years. However, the HPV vaccination rate among Filipino women remains to be unsatisfactory. HPV vaccination has only been included in the Philippine Department of Health's community-based National Immunization Program in 2015. Despite these efforts, the Philippines currently ranks last on HPV program coverage among low-middle income countries, with coverage of only 23% of the target female population for the first dose and 5% for the final dose. The principal reason for the non-acceptance of HPV vaccines was the perceived high cost of vaccination. The low utilization of available cervical cancer screening tests such as Pap smear and visual inspection with acetic acid hampered the Philippines' control and prevention of HPV infection and cervical cancer. Among those diagnosed with cervical cancer in the Philippines, only an estimated 50% to 60% receive some form of treatment. To this end, we summarize the burden of HPV infection and cervical cancer on Filipinos and the risk factors associated with the disease. We present the current screening, diagnostics, treatment, and prevention of HPV-related diseases in the Philippines. Lastly, we also propose solutions on how each building block in health systems can be improved to eliminate HPV infection and reduce the burden of cervical cancer in the Philippines.

Exosomes from cervical cancer cells facilitate pro-angiogenic endothelial reconditioning through transfer of Hedgehog-GLI signaling components

BACKGROUND

Angiogenic switch is a hallmark feature of transition from low-grade to high-grade cervical intraepithelial neoplasia (CIN) in cervical cancer progression. Therefore, early events leading to locally-advanced cervical metastatic lesions demand a greater understanding of the underlying mechanisms. Recent leads indicate the role of tumor-derived exosomes in altering the functions of endothelial cells in cervical cancer, which needs further investigation.

METHODS

Exosomes isolated from cervical cancer cell lines were assessed for their angiogenic effect on the human umbilical vein endothelial cells (HUVEC) using tube formation and wound healing assay. The exosomal uptake by HUVEC cells was monitored using PKH-67 labelling followed by fluorescence microscopy. Alterations in Hh-GLI signaling components, PTCH1 and GLI1, in HUVEC were measured by immunoblotting. Changes in angiogenesis-related transcripts of vascular endothelial growth factor VEGF-A, VEGF-B, VEGFR2 and angiopoietin-1, angiopoietin-2, osteopontin were measured in exosome-treated HUVEC and in the exosomal RNA by RT-PCR.

RESULTS

Enhanced tube formation, with an increased number of nodes and branching was observed in HUVEC's treated with exosomes derived from different cervical cancer cell lines. HPV-positive (SiHa and HeLa) cells' exosomes were more angiogenic. Exosome-treated HUVEC showed increased migration rate. PKH-67 labelled exosomes were found internalized in HUVEC. A high level of PTCH1 protein was detected in the exosome-treated endothelial cells. Subsequent RT-PCR analysis showed increased transcripts of Hh-GLI downstream target genes VEGF-A, VEGFR2, angiopoietin-2, and decreased expression of VEGF-B, and angiopoietin-1, suggestive of active Hh-GLI signaling. These effects were more pronounced in HUVEC's treated with exosomes of HPV-positive cells. However, these effects were independent of tumor-derived VEGF-A as exosomal cargo lacked VEGF-A transcripts or proteins.

CONCLUSION

Overall, the data showed cervical cancer exosomes promote pro-angiogenic response in endothelial cells via upregulation of Hh-GLI signaling and modulate downstream angiogenesis-related target genes. The study provides a novel exosome-mediated mechanism potentially favoring cervical angiogenesis and thus identifies the exosomes as potential pharmacological targets against locally-advanced metastatic cervical lesions.

Correlation between melatonin concentration and cytokines in cervical mucus in positive samples for the presence of human papillomavirus

The human papillomavirus (HPV) is the main causative agent of cervical cancer, characterized by neoplastic lesions in the cervix. Based on the morphology of the cells of the uterine cervix, the findings are classified as negative intraepithelial lesions for malignancies, low-grade squamous intraepithelial lesions, high-grade squamous intraepithelial lesions (HSILs), atypical squamous cells of undetermined significance and atypical squamous cells of undetermined significance without excluding HSILs (ASCs-H). The progression of neoplastic lesions is related to the cervix's microenvironmental inflammatory process and mediated by the expression and stimulation of cytokines. Cervical mucus is a viscous liquid secretion composed of proteins, inorganic components, pro-and anti-inflammatory agents, and an important protective barrier. This study aimed to quantify and correlate cytokines IL-6, IL-8, and IL-10 and Melatonin in cervical mucus. According to the results, a decrease in MLT was observed in LSIL, HSI, and ASC-H groups than in the NILM group. The cytokines IL-6 and IL-8 showed greater expression in the LSIL and HSIL groups than the NILM group. HSIL group showed a negative correlation between the MLT and IL-6 and IL-8 concentrations. In the ASC-US group, IL8 level was positively correlated to MLT levels. We suggest that IL-6, IL-8, and MLT levels in HSIL groups are decisive for the progression of neoplastic lesions in HPV infections. New cervical cancer treatment strategies may include cytokine and melatonin control targets for effective immunotherapy.

Functional impact of allelic variations/haplotypes of TNF-α on reproductive tract infections in Indian women

The aim of the present study is to investigate the functional role of TNF-α single-nucleotide polymorphisms/haplotypes in an association with reproductive tract infections (RTIs) in symptomatic and asymptomatic women. A total of 850 consecutive subjects consisting of 400 cases and 450 healthy controls, were screened for RTIs, along with their risk factors and associated symptoms. The propensity score matching was performed to reduce the confounding bias arise owing to covariates and to balance the data between two groups. A total of 211 pairs (1:1) have been created. Genotyping of rs1800629 (-308) and rs361525 (-238) SNPs of TNF-α was done by PCR-RFLP followed by sequencing. The functional implication of TNF-α SNPs in an association with RTIs was also checked by using ELISA. The frequency of -238A allele and -308A allele was found to be twofold (P < 0.0001) and threefold (P < 0.0001) higher in the presence of RTIs. AA haplotype emerged as a major player in an association with RTIs and elevated TNF-α expression. The present study revealed the functional role of rs1800629 (-308) and rs361525 (-238) of TNF-α in an association with RTIs. This information may be used to establish biomarkers for an inflammatory response during the persistence of RTIs.

HPV post-infection microenvironment and cervical cancer

Human papillomavirus (HPV) is the most common sexually transmitted virus worldwide. More than 99% of cervical cancer cases are associated with certain types of HPVs, termed high-risk types. In addition to the well-known transformative properties, HPVs-infected cells actively instruct the local milieu and create a supportive post-infection microenvironment (PIM), which is becoming recognized as a key factor for the viral persistence, propagation, and malignant progression. The PIM is initiated and established via a complex interplay among virus-infected cells, immune cells, and host stroma, as well as their derived components including chemokines, cytokines, extracellular vesicles, and metabolites. In this review, we summarize the current understanding of these key components, characteristics, and effects of the PIM, and highlights the prospect of targeting the PIM as a potential strategy to improve therapeutic outcomes for cervical cancer.

TNFR1 single nucleotide polymorphisms are not associated with cervical HPV-induced pre-malignant lesion but regulate in situ cervical TNFR1 expression

TNF-α is involved in HPV infection control by triggering cell signaling through binding in specific receptors TNFR1 and TNFR2. Genetic polymorphisms in these receptors may influence TNF-α signaling. Herein, we investigated TNFR1 rs767455 and rs2234649 single nucleotide polymorphisms, and TNFR1 protein expression in cervical squamous intraepithelial lesions (SIL) to identify their role in cervical pre-malignant development. SIL patients (n = 179) and healthy volunteers (n = 227) were enrolled for TNFR1 genotyping analysis by PCR-RFLP in blood samples and TNFR1 protein expression in cervical tissue by immunohistochemistry. No statistical differences regard genotypes and allelic frequencies for both polymorphisms were observed. Cervical TNFR1-expressing cells were rare in epithelium and basal layer regardless the groups. However, a progressive increase in infiltrating cells was observed in the stromal area, mainly in high SIL (HSIL) group compared to low SIL (LSIL, p < 0.001) and control (p < 0.001) groups. TNFR1-expressing cells frequency was higher in TNFR1 rs767455AG/GG (p < 0.001), and in rs2234649AA (p < 0.001) genotypes carries in HSIL subgroup. These data indicated that TNFR1-expression is abrogated in cervical epithelium, where HPV-induced pre-malignant lesion occurs, increasing its frequency in inflammatory cells in stroma, and is genetically controlled by TNFR1 rs767455AG/GG and rs234649AA genotypes. These biomarkers may be useful to identify cervical precancerous lesions progression.

The Roles of Matricellular Proteins in Oncogenic Virus-Induced Cancers and Their Potential Utilities as Therapeutic Targets

Matricellular proteins differ from other classical extracellular matrix proteins; for instance, they are transiently expressed as soluble proteins rather than being constitutively expressed in pathological conditions, such as acute viral infections. Accumulating studies have revealed that matricellular proteins, including osteopontin and tenascin-C, both of which interact with integrin heterodimers, are involved in inflammatory diseases, autoimmune disorders, and cancers. The concentrations of these matricellular proteins are elevated in the plasma of patients with certain types of cancers, indicating that they play important roles in oncogenesis. Chronic viral infections are associated with certain cancers, which are distinct from non-viral cancers. Viral oncogenes play critical roles in the development and progression of such cancers. It is vital to investigate the mechanisms of tumorigenesis and, particularly, the mechanism by which viral proteins induce tumor progression. Viral proteins have been shown to influence not only the viral-infected cancer cells, but also the stromal cells and matricellular proteins that constitute the extracellular matrix that surrounds tumor tissues. In this review, we summarize the recent progress on the involvement of matricellular proteins in oncogenic virus-induced cancers to elucidate the mechanism of oncogenesis and consider the possible role of matricellular proteins as therapeutic targets in virus-induced cancers.

The human papillomavirus E7 oncoprotein as a regulator of transcription

High-risk human papillomaviruses (HPVs) encode oncoproteins which manipulate gene expression patterns in the host keratinocytes to facilitate viral replication, regulate viral transcription, and promote immune evasion and persistence. In some cases, oncoprotein-induced changes in host cell behavior can cause progression to cancer, but a complete picture of the functions of the viral oncoproteins in the productive HPV life cycle remains elusive. E7 is the HPV-encoded factor most responsible for maintaining cell cycle competence in differentiating keratinocytes. Through interactions with dozens of host factors, E7 has an enormous impact on host gene expression patterns. In this review, we will examine the role of E7 specifically as a regulator of transcription. We will discuss mechanisms of regulation of cell cycle-related genes by E7 as well as genes involved in immune regulation, growth factor signaling, DNA damage responses, microRNAs, and others pathways. We will also discuss some unanswered questions about how transcriptional regulation by E7 impacts the biology of HPV in both benign and malignant conditions.

The Interaction Between Human Papillomaviruses and the Stromal Microenvironment

Human papillomaviruses (HPVs) are small, double-stranded DNA viruses that replicate in stratified squamous epithelia and cause a variety of malignancies. Current efforts in HPV biology are focused on understanding the virus-host interactions that enable HPV to persist for years or decades in the tissue. The importance of interactions between tumor cells and the stromal microenvironment has become increasingly apparent in recent years, but how stromal interactions impact the normal, benign life cycle of HPVs, or progression of lesions to cancer is less understood. Furthermore, how productively replicating HPV impacts cells in the stromal environment is also unclear. Here we bring together some of the relevant literature on keratinocyte-stromal interactions and their impacts on HPV biology, focusing on stromal fibroblasts, immune cells, and endothelial cells. We discuss how HPV oncogenes in infected cells manipulate other cells in their environment, and, conversely, how neighboring cells may impact the efficiency or course of HPV infection.

Transforming growth factor-β1 in carcinogenesis, progression, and therapy in cervical cancer

Transforming growth factor β1 (TGF-β1) is a multifunctional cytokine that plays important roles in cervical tumor formation, invasion, progression, and metastasis. TGF-β1 functions as a tumor inhibitor in precancerous lesions and early stage cancers of cervix whereas as a tumor promoter in later stage. This switch from a tumor inhibitor to a tumor promoter might be due to various alterations in TGF-β signaling pathway, such as mutations or loss of expression of TGF-β receptors and SMAD proteins. Additionally, the oncoproteins of human papillomaviruses have been shown to stimulate TGF-β1 expression, which in turn suppresses host immune surveillance. Thus, in addition to driving tumor cell migration and metastasis, TGF-β1 is believed to play a key role in promoting human papillomavirus infection by weakening host immune defense. In this article, we will discuss the role of TGF-β1 in the expression, carcinogenesis, progression, and therapy in cervical cancers. A better understanding of this cytokine in cervical carcinogenesis is essential for critical evaluation of this cytokine as a potential prognostic marker and therapeutic target.

Lack of Associations between TNF-αPolymorphisms and Cervical Cancer in Thai women

The risk of developing cervical cancer in women infected with human papillomavirus (HPV) may be influenced by an individual's genetic susceptibility. Published data linking single nucleotide polymorphisms (SNPs) in the tumor necrosis factor-alpha (TNF-?) promoter region at positions -308G>A (rs1800629) and -238G>A (rs361525) to cervical cancer risk have been inconclusive. In this study, we examined 251 cervical specimens and classified them into two groups according to their cytological findings: 121 cancer cases and 130 controls (low-grade squamous intraepithelial lesion and normal cytology). All specimens were typed by PCR and sequencing for TNF-αpromoter -308G>A (rs1800629) and -238G>A (rs361525). The genotype distribution of SNPs in either rs1800629 or rs361525 did not significantly demonstrate higher frequency in the cancer group (p=0.621 and p=0.68, respectively). Based on these results, neither the TNF-αpromoter -308G>A (rs1800629) nor the -238G>A (rs361525) polymorphism presents a major risk factor for cervical cancer among Thai women. Larger studies are necessary to elucidate possible genetic mechanisms influencing cervical cancer development.

Growth factor progranulin contributes to cervical cancer cell proliferation and transformation in vivo and in vitro

OBJECTIVE

The growth factor progranulin (PGRN) is overexpressed in a number of tumors. We aimed to investigate the expression and role of PGRN in cervical cancer tumorigenesis.

METHODS

PGRN expression and secretion was assessed in cells and normal and cancerous cervical tissues by Western blot analysis, ELISA or immunohistochemistry. The role of PGRN in cervical carcinogenesis was explored by cell-proliferation, colony-formation and tumor-growth assays. We assessed the role of PGRN-mediated signaling in the cervical cell with specific inhibitors.

RESULTS

PGRN expression was upregulated in cervical cancer cell lines and tissue. PGRN promoted the transformation of human cervical mucosa epithelial H8 cells in vitro and tumor formation in vivo. Knockdown of PGRN expression in cervical cancer cells in vivo decreased cell proliferation and slowed tumor growth. PGRN stimulated cervical cell proliferation, and transformation was mediated, at least in part, by Akt and Erk signaling.

CONCLUSIONS

PGRN is overexpressed in cervical cancer and promotes the malignant growth and transformation of cervical cells. Therefore, PGRN plays a critical role in carcinogenesis of cervical cancer and shows promise for therapeutic strategies for cervical cancer.

HPV16 E2-mediated potentiation of NF-κB activation induced by TNF-α involves parallel activation of STAT3 with a reduction in E2-induced apoptosis

Human papilloma virus is associated with cervical and other tumors, and several cellular conditions also play an important role in carcinogenesis. Human papilloma virus (HPV)-infected cells exhibit activation of NF-κB and STAT3 (mediators of inflammation), but little is known about their regulation by HPV. This study attempts to understand the role of HPV16 E2, an important early protein of HPV16, in the regulation of NF-κB and STAT3 by reporter assays, quantitative reverse transcriptase-polymerase chain reaction, and immunoblotting. We demonstrate that E2 enhances NF-κB activation induced by TNF-α, a proinflammatory cytokine, in both non-tumor- and tumor-derived epithelial cell lines besides potentiating STAT3 transcriptional activity induced by TNF-α in HEK293 cells. E2 increases the expression of RelA and its transcriptional activation, and retention of E2 was observed in the nucleus with significant interaction with RelA (immunoprecipitation) upon TNF-α treatment. Transfection with shRNA-RelA or pretreatment with a STAT3 inhibitor had a negative effect on the ability of E2 to enhance TNF-α-induced NF-κB activation. Experiments with co-expression of a mutant of STAT3 with E2 also suggested that the activation of STAT3 is indispensible for TNF-α-induced NF-κB activation. Inhibition of STAT3 activation enhanced E2-induced apoptosis, whereas parallel activation of NF-κB and STAT3 by the combined action of E2 and TNF-α increased the expression of their common targets, cyclin-D1, c-Myc, survivin, and Bcl-2, leading to a decrease in E2-induced apoptosis (viability and cell cycle). Our results reveal novel mechanisms by which E2 may regulate NF-κB and STAT3 activation in the presence of TNF-α with implications on the survival of HPV-infected cells.

Hypoxia-inducible factor 1 and its role in viral carcinogenesis

The advent of modern molecular biology has allowed for the discovery of several mechanisms by which oncoviruses promote carcinogenesis. Remarkably, nearly all human oncogenic viruses increase levels of the transcription factor hypoxia-inducible factor 1 (HIF-1). In this review, we highlight HIF-1׳s significance in viral oncogenesis, while providing an in-depth analysis of its activation mechanisms by the following oncoviruses: human papillomaviruses (HPVs), hepatitis B/C viruses (HBV/HCVs), Epstein-Barr virus (EBV), Kaposi׳s sarcoma-associated herpes virus (KSHV), and human T-cell lymphotropic virus (HTLV-1). We discuss virus-induced HIF-1׳s role in transcriptional upregulation of metabolic, angiogenic, and microenvironmental factors that are integral for oncogenesis. Admittedly, conclusive evidence is lacking as to whether activation of HIF-1 target genes is necessary for malignant transformation or merely a result thereof. In addition, a complete understanding of host-virus interactions, the effect of viral genomic variation, and the clinical (and potential therapeutic) relevance of HIF-1 in viral oncogenesis warrant further investigation.

Molecular profiling of cervical neoplasia

Cervical cancer, a potentially preventable disease, remains the second most common malignancy in women worldwide. Human papillomavirus is the single most important etiological agent in cervical cancer, contributing to neoplastic progression through the action of viral oncoproteins, mainly E6 and E7, which interfere with critical cell cycle pathways, p53 and retinoblastoma. However, evidence suggests that human papillomavirus infection alone is insufficient to induce malignant changes and that other host genetic variations are important in the development of cervical cancer. This article will discuss the latest molecular profiling techniques available and review the published literature relating to their role in the diagnosis and management of cervical dysplasia and cancer. It is hoped that these techniques will allow the detection of novel biomarkers at DNA, RNA, microRNA and protein levels, which may ultimately play a role in facilitating early disease diagnosis and in predicting response to therapies, thus allowing the development of personalized treatment strategies.

The PPARβ agonist L-165041 promotes VEGF mRNA stabilization in HPV18-harboring HeLa cells through a receptor-independent mechanism

Peroxisome Proliferator-Activated Receptor-β (PPARβ) is a ligand-inducible transcription factor activated by both natural (fatty acids and derivatives) and high affinity synthetic agonists. It is thought to play a role in angiogenesis development and Vascular Endothelial Growth Factor (VEGF) regulation but its contribution remains unclear. Until now, the PPARβ agonism effect on VEGF expression in cervical cancer cells was unknown. This led to our interest in assessing the effect of PPARβ activation on the regulation of different VEGF isoforms mRNA expression and the impact of E6 viral oncoprotein and its target p53 on this regulation in cervical cancer cells. Here, we showed that the PPARβ agonist L-165041 induces VEGF(121), VEGF(165) and VEGF(189) expression in HPV (Human Papillomavirus) positive HeLa cells but not in HPV negative cells. The underlying mechanisms did involve neither E6 oncoprotein nor p53. We highlighted a novel mode of PPARβ ligand action including a post-transcriptional regulation of VEGF mRNA expression through the p38 MAPK signaling pathway and the activation of the mRNA-stabilizing factor HuR. But most importantly, we clearly demonstrated that L-165041 acts independently of PPARβ since its effect was not reversed by a chemical inhibition with a specific antagonist and the siRNA-mediated knockdown of the nuclear receptor. As VEGF is crucial for cancer development, the impact of PPARβ ligands on VEGF production is of high importance. Thus, the molecular mechanism of their action has to be elucidated and as a result, PPARβ agonists currently in clinical trials should be carefully monitored.

Psychosocial functioning and vascular endothelial growth factor in patients with head and neck cancer

BACKGROUND

Psychosocial functioning is associated with vascular endothelial growth factor (VEGF) in various patient populations. This study examined whether psychosocial functioning in patients with head and neck squamous cell carcinoma (HNSCC) is associated with tumor VEGF expression, a protein that stimulates angiogenesis and is associated with poor prognosis.

METHODS

Forty-two newly diagnosed patients completed assessments of psychosocial functioning (ie, depressive symptoms, perceived stress, anxiety, social support) before surgery. Tumor samples were obtained for VEGF analysis and human papillomavirus (HPV)-typing.

RESULTS

Poorer psychosocial functioning was associated with greater VEGF expression controlling for disease stage (odds ratio [OR], 4.55; 95% confidence interval [CI], 1.72-12.0; p < .01). When examined by HPV status, the association between psychosocial functioning and VEGF remained significant among patients who were HPV negative (OR, 5.50; 95% CI, 1.68-17.3; p < .01), but not among patients who were HPV positive.

CONCLUSION

These findings inform our understanding of the biobehavioral pathways that may contribute to poor outcomes in non-HPV-associated HNSCCs.

Association of tumor necrosis factor-alpha promoter variants with risk of HPV-associated oral squamous cell carcinoma

Background

Tumor necrosis factor alpha (TNF-α) plays an important role in inflammation, immunity, and defense against infection and clearance of human papillomavirus (HPV). Thus, genetic variants may modulate individual susceptibility to HPV-associated oral squamous cell carcinoma (OSCC).

Methods

In this study we genotyped four common single nucleotide polymorphisms (SNPs) in the TNF-α promoter [ −308G > A(rs1800629), -857C > T (rs1799724), -863C > A (rs1800630), and -1031T > C (rs1799964)] and determined HPV16 serology in 325 OSCC cases and 335 matched controls and tumor HPV status in 176 squamous cell carcinomas of the oropharynx (SCCOP) patients. Univariate and multivariable logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

Results

We found that HPV16 seropositivity alone was associated with an increased risk of OSCC (OR, 3.1; 95% CI, 2.1–4.6), and such risk of HPV16-associated OSCC was modified by each SNP. Patients with both HPV16 seropositivity and variant genotypes for each SNP had the highest risk when using patients with HPV16 seronegativity and a wild-type genotype as a comparison group. Moreover, similar results were observed for the combined risk genotypes of four variants and all such significant associations were more pronounced in several subgroups, particularly in SCCOP patients and never smokers. Notably, the combined risk genotypes of four variants were also significantly associated with tumor HPV-positive SCCOP.

Conclusion

Taken together, these results suggest that TNF-α SNPs may individually or, more likely, jointly affect individual susceptibility to HPV16-associated OSCC, particularly SCCOP and never smokers. Validation of our findings is warranted.

Genetic susceptibility of cervical cancer

Epidemiological and laboratory-based studies have identified infection with one of 15 high-risk human papillomavirus (HPV) types as a necessary but not sufficient cause of cervical cancer. The prevalence of genital HPV infections is high in young women, but most of the infections regress without interventions. Host genetic variations in genes involved in immune response pathways may be related to HPV clearance, and HPV E6/E7 oncoproteins interacting or downstream genes, both coding and non-coding, may contribute to the outcome of high risk HPV infection and cervical cancer. Of specific interest for this review has been the selection of genetic variants in genes involved in the above-referred pathways with a summary of their applications in association studies. Because the supportive and opposing data have been reported in different populations, well-designed international collaborative studies need to be conducted to define the consistency of the associations, paving the way to better define the patients at high risk of developing cervical cancer.

Human papillomavirus up-regulates MMP-2 and MMP-9 expression and activity by inducing interleukin-8 in lung adenocarcinomas

Human papillomavirus (HPV) infection is associated with non-smoking female lung cancer. Our previous report demonstrated that HPV 16 promotes lung tumor cell progression by up-regulating interleukin-17 (IL-17). IL-17 and its downstream signaling mediator, interleukin-8 (IL-8), have been implicated to modulate a variety of pro-angiogenic factors and play important roles in tumor angiogenesis and metastasis. Accordingly, we hypothesized that HPV infection may potentiate tumorigenic and metastatic characteristics of the infected cells through IL-8. The goal of the present study was to determine whether HPV infection in lung adenocarcinoma cells can promote the expression of IL-8 and metalloproteinases (MMPs) to make the transformed cells equipped with angiogenic and metastatic characteristics. The expression of IL-8 and MMPs in HPV 16 E6-transfected H1299 cells was analyzed to examine the hypothesis. HPV 16 E6 up-regulates pro-angiogenic MMP-2 and MMP-9 through inducing IL-8 expression in lung cancer cells. The results indicate that, in addition to cell proliferation-related machinery, HPV infection promotes the expression and activities of angiogenic and metastatic molecules in lung adenocarcinoma cells. The cytokines induced by HPV infection may work together to confer the malignant and tumorigenic potentials on the infected cells by promoting machineries of growth, angiogenic and metastatic characteristics.

Effects of Acanthus ebracteatus Vahl on tumor angiogenesis and on tumor growth in nude mice implanted with cervical cancer

Purpose

The aim of this study was to examine the effects of the crude extract of Acanthus ebracteatus Vahl (AE) on tumor growth and angiogenesis by utilizing a tumor model in which nude mice were implanted with cervical cancer cells containing human papillomavirus 16 DNA (HPV-16 DNA).

Materials and methods

The growth-inhibitory effect of AE was investigated in four different cell types: CaSki (HPV-16 positive), HeLa (HPV-18 positive), hepatocellular carcinoma cells (HepG2), and human dermal fibroblast cells (HDFs). The cell viabilities and IC₅₀ values of AE were determined in cells incubated with AE for different lengths of time. To conduct studies in vivo, female BALB/c nude mice (aged 6–7 weeks, weighing 20–25 g) were used. A cervical cancer-derived cell line (CaSki) with integrated HPV-16 DNA was injected subcutaneously (1 × 10⁷ cells/200 μL) in the middle dorsum of each animal (HPV group). One week after injection, mice were fed orally with AE crude extract at either 300 or 3000 mg/kg body weight/day for 14 or 28 days (HPV-AE groups). Tumor microvasculature and capillary vascularity were determined using laser scanning confocal microscopy. Tumor tissue was collected from each mouse to evaluate tumor histology and vascular endothelial growth factor (VEGF) immunostaining.

Results

The time-response curves of AE and the dose-dependent effect of AE on growth inhibition were determined. After a 48-hour incubation period, the IC₅₀ of AE in CaSki was discovered to be significantly different from that of HDFs (P < 0.05). A microvascular network was observed around the tumor area in the HPV group on days 21 and 35. Tumor capillary vascularity in the HPV group was significantly increased compared with the control group (P < 0.001). High-dose treatment of AE extract (HPV-3000AE group) significantly attenuated the increase in VEGF expression and tumor angiogenesis in mice that received either the 14- or 28-day treatment period (P < 0.001).

Conclusion

Our novel findings demonstrated that AE crude extract could inhibit cervical cancer growth, VEGF expression, and angiogenesis in a CaSki-cell transplant model in mice.

Selenium enhances the efficacy of Radachlorin mediated-photodynamic therapy in TC-1 tumor development

Selenium, an essential trace element possessing anti-carcinogenic properties, can induce apoptosis in cancer cells. Our goal was to investigate the enhanced antitumor effects of photodynamic therapy (PDT) plus selenium in TC-1 tumor cells and implanted mice. Cell viability was evaluated at various time intervals after PDT treatment and/or selenium by methyl thiazolyl tetrazolium (MTT) assay. When only PDT treatment was administered to TC-1 tumor cells, TC-1 cell growth recovered over time. On the other hand, co-treatment of PDT and selenium extended the inhibition time of tumor cell growth. Co-treatment of PDT and selenium showed serious morphological changes in TC-1 cells and induced a more apoptotic population by FACS analysis. By signal transduction pathway SuperArray analysis, genes closely involved in the NFκB, p53 and phopholipase C pathways, such as VCAM1, MDM2 and FOS, were significantly downregulated at least 10-fold in TC-1 cells following PDT and selenium cotreatment. In an in vivo study, tumor-bearing mice were intravenously injected with Radachlorin 3 h before irradiation with 300 J/cm2 of light. Selenium was administered daily for 20 days. Combination therapy against the mouse tumors generated by TC-1 cells was more effective than PDT or selenium alone. These data suggest that selenium plus PDT can induce a significant tumor suppression response compared with PDT alone. Additionally, it can be an effective anticancer therapy strategy.

Molecularly targeted therapies in cervical cancer. A systematic review

Cervical cancer represents the third most common cause of female cancer mortality. Even with the best currently available treatment, a significant proportion of patients will experience recurrence and eventually die. Evidently, there is a clear need for the development of new agents with novel mechanisms of action in this disease. A number of biological agents modulating different signal transduction pathways are currently in clinical development, inhibiting angiogenesis, targeting epidermal growth factor receptor, cell cycle, histone deacetylases, cyclooxygenase-2 (COX-2), or mammalian target of rapamycin (mTOR). This is the first systematic review of the literature to synthesize all available data emerging from trials and evaluate the efficacy and safety of molecularly targeted drugs in cervical cancer. However, it should be stressed that relatively fewer molecularly targeted agents have been tested in cervical cancer in comparison with other cancer types; of note, no related phase 3 trials have been published and consequently no agent has been approved for use in clinical practice. Nevertheless, the promising results of bevacizumab in therapeutic trials for cervical cancer have shown that targeting the VEGF pathway is an attractive therapeutic strategy. As knowledge accumulates on the molecular mechanisms underlying carcinogenesis in the cervix, the anticipated development and assessment of molecularly targeted agents may offer a promising perspective for cervical cancer.

Active and passive anticytokine immune therapies: current status and development

Anticytokine (AC) immune therapies derived from vaccine procedures aim at enhancing natural immune defense mechanisms ineffective to contain abnormally produced cytokines and counteract their pathogenic effects. Given their short half-life, cytokines, the production of which by effector immune cells (T and B lymphocytes, antigen-presenting cells (APCs), natural killer (NK) and endothelial cells) is inducible and controlled by negative feedback regulation, (1) exert locally their signaling to paracrine/autocrine target responder cells carrying high-affinity membrane receptors and (2) are commonly present at minimal concentration in the body fluid (lymph, serum). Aberrant signaling triggered by cytokines, uncontrolly released by effector immune cells or produced by cancer and other pathologic cells, contribute to the pathogenesis of chronic diseases including cancer, viral infections, allergy, and autoimmunity. To block these ectopic cytokine signaling and prevent their pathogenic effects, AC Abs supplied either by injections (passive AC immune therapy) or elicited by immunization with cytokine-derived immunogenes called Kinoids (active AC immune therapy) proved to be experimentally effective and safe. In this review, we detailed the rationale and the requirements for the use of AC immunotherapies in humans, the proof of efficacy of these medications in animal disease models, and their current clinical development and outcome, including adverse side effects they may generate. We particularly show that, to date, the benefit:risk ratio of AC immune therapies is highly positive.

Viruses as key regulators of angiogenesis

Angiogenesis is an important physiological process that is controlled by a precise balance of growth and inhibitory factors in healthy tissues. However, environmental and genetic factors may disturb this delicate balance, resulting in the development of angiogenic diseases, tumour growth and metastasis. During the past decades, extensive research has led to the identification and characterization of genes, proteins and signalling pathways that are involved in neovascularization. Moreover, increasing evidence indicates that viruses may also regulate angiogenesis either directly, by (i) producing viral chemokines, growth factors and/or receptors or (ii) activating blood vessels as a consequence of endothelial cell tropism, or indirectly, by (iii) modulating the activity of cellular proteins and/or (iv) inducing a local or systemic inflammatory response, thereby creating an angiogenic microenvironment. As such, viruses may modulate several signal transduction pathways involved in angiogenesis leading to changes in endothelial cell proliferation, migration, adhesion, vascular permeability and/or protease production. Here, we will review different mechanisms that may be applied by viruses to deregulate the angiogenic balance in healthy tissues and/or increase the angiogenic potential of tumours.

Overexpression of human papillomavirus (HPV) type 16 oncoproteins promotes angiogenesis via enhancing HIF-1α and VEGF expression in non-small cell lung cancer cells

HPV-16 infection may play an important role in the development of non-small cell lung cancer (NSCLC) among never-smokers. Due to the critical role of angiogenesis in NSCLC development, we describe here the effect of HPV-16 oncoproteins on angiogenesis in NSCLC and the underlying mechanisms. We found that overexpression of HPV-16 E6 and E7 oncoproteins in NSCLC cells significantly promoted angiogenesis both in vitro and in vivo, and correspondingly, an enhanced expression of HIF-1α and VEGF, important pro-angiogenic factors in tumor angiogenesis. Meanwhile, overexpression of HPV-16 oncoproteins also led to HIF-1α-dependent increases in the secretion of several other pro-angiogenic factors, including IL-8. Our findings suggest that HPV-16 oncoproteins contribute to the development of NSCLC possibly by promoting HIF-1α/VEGF-mediated tumor angiogenesis.

Transforming activity of a novel mutant of HPV16 E6E7 fusion gene

An optimized recombinant HPV16 E6E7 fusion gene (HPV16 ofE6E7) was constructed according to codon usage for mammalian cell expression, and a mutant of HPV16 ofE6E7 fusion gene (HPV16 omfE6E7) was generated by site-directed mutagenesis at L57G, C113R for the E6 protein and C24G, E26G for the E7 protein for HPV16 ofE6E7 [patent pending (CN 101100672)]. The HPV16 omfE6E7 gene constructed in this work not only lost the transformation capability to NIH 3T3 cells and tumorigenicity in SCID mice, but also maintained very good stability and antigenicity. These results suggests that the HPV16 omfE6E7 gene should undergo further study for application as a safe antigen-specific therapeutic vaccine for HPV16-associated tumors.

Expression of human papillomavirus type 16 E7 is sufficient to significantly increase expression of angiogenic factors but is not sufficient to induce endothelial cell migration

Tumor suppressors negatively regulate angiogenesis, an essential step in tumor progression. Together, HPV 16 E6 and E7 proteins, which target p53 and pRb family members, respectively, for degradation, increase the expression of two angiogenic inducers, VEGF and IL-8, in primary foreskin keratinocytes (HFKs). Conditioned media from such cells are sufficient to alter endothelial cell behavior. Here, the individual contribution of E6 and E7 to angiogenesis was investigated. E7 and, to a lesser extent E6, increased expression of VEGF and IL-8. Nevertheless, neither conditioned media from HPV 16 E6 nor E7-expressing HFKs were sufficient to induce migration of endothelial cells. Conditioned media from HFKs expressing the HPV 16 E6 and the E7 mutant E7C24G, which can target p107 and p130 but not pRb for degradation, contained increased levels of VEGF and IL-8. The results suggest that the mechanism of HPV 16 E7-mediated increased levels of VEGF is pRb-independent.

Stromal issues in cervical cancer: a review of the role and function of basement membrane, stroma, immune response and angiogenesis in cervical cancer development

The carcinogenesis of cervical carcinoma implies an intricate interplay of neoplastic, human papillomavirus infected epithelial cells and stromal tissue, in which different factors have distinct but interacting influence. Persistent infection with an oncogenic human papillomavirus type may lead to epithelial dysplasia with progressive severity. To access the adjacent stromal tissue, tumour cells have to breach the basement membrane. The stroma partly controls tumour growth, invasion and angiogenesis. Last but not least there is considerable influence of the immune response. In this review we describe the importance of various stromal factors in carcinogenesis of cervical cancer.

Dendrosome-based delivery of siRNA against E6 and E7 oncogenes in cervical cancer

Although small interfering RNA (siRNA) treatment holds great promise for the treatment of cancers, the field has been held back by the availability of suitable delivery vehicles. For cervical cancer the E6 and E7 oncogenes are ideal siRNA targets for treatment. The purpose of the present study was to explore the potential of dendrosomes for the delivery of siRNA targeting E6 and E7 proteins of cervical cancer cells in vitro. Optimization of dendrimer generation and nitrogen-to-phosphate (N/P) ratio was carried out using dendrimer-fluorescein isothiocyanate oligo complexes. The optimized N/P ratios were used in formulating complexes between dendrimers and siRNA targeting green fluorescence protein (siGFP). Although formulation 4D100 (dendrimer-siRNA complex) displayed the highest GFP knockdown, it was also found to be highly toxic to cells. In the final formulation 4D100 was encapsulated into dendrosomes so as to mask these toxic effects. The optimized dendrosomal formulation (DF), DF3 was found to possess a siGFP-entrapment efficiency of 49.76% +/- 1.62%, vesicle size of 154 +/- 1.73 nm, and zeta potential of +3.21 +/- 0.07 mV. The GFP knockdown efficiency of DF3 (dendrosome) was found to be almost identical to that of 4D100, but the former was completely nontoxic to the cells. DF3 containing siRNA against E6 and E7 was found to knock down the target genes considerably, as compared with the other formulations tested. Our results imply that dendrosomes hold potential for the delivery of siRNA and that a suitable targeting strategy could be useful for applications in vivo.

FROM THE CLINICAL EDITOR

siRNA treatment holds great promise for the treatment of cancers, but overall, the availability of suitable delivery vehicles remains a major issue. The purpose of this study was to explore the potential of dendrosomes for the delivery of siRNA targeting specific proteins in cervical cancer cells in vitro. The results suggest that dendrosomes hold potential for the delivery of siRNA and a suitable targeting strategy could be useful for applications in vivo.

Hypoxia-specific stabilization of HIF-1alpha by human papillomaviruses

Human papillomaviruses (HPV) are the causative agents of cervical cancer and have been shown to increase expression of pro-angiogenic factors from infected cells. Many angiogenic factors are regulated by hypoxia inducible factor 1alpha (HIF-1alpha). We investigated whether HPV31 affects the levels of HIF-1alpha under normal and hypoxic conditions. Our studies indicate that cells containing complete HPV31 genomes showed enhanced levels of HIF-1alpha upon treatment with the hypoxia mimic DFO, which resulted from protein stabilization and led to increased expression of some but not all HIF-1alpha target genes. Both HPV E6 and E7 were able independently to enhance induction of HIF-1alpha upon DFO treatment. Enhancement of HIF-1alpha stability was not restricted to high-risk HPV types, as HPV11, a low risk HPV type, mediated a similar effect. These findings shed light on mechanisms by which HPV contributes to angiogenesis both in benign cervical lesions and in cervical cancers.

Gene silencing with siRNA targeting E6/E7 as a therapeutic intervention in a mouse model of cervical cancer

OBJECTIVE

Selective silencing of HPV oncogenes using short interfering RNA (siRNA) blocks E6/E7 expression and restores normal p53 and Rb function. Our objective was to determine if siRNA targeting E6/E7 would inhibit the growth of established tumors in a mouse model of cervical cancer.

METHODS

In vitro studies were performed using unique siRNA sequences to confirm their ability to target and reduce E6/E7 mRNA and restore functioning p53. Next, siRNA targeting lamin was injected daily for three days into tumors established from HPV 16 positive CaSki human cervical cancer cells. Immunohistochemistry and branched DNA gene quantification were used to determine distribution and duration of activity of these siRNA. For our therapeutic studies tumors were directly injected with siRNA targeting E6/E7, non-targeting control siRNA, or saline. In preliminary experiments injections were daily or every three days for a total of three doses. A second therapeutic experiment utilized every three day dosing for 35 days. Tumor volume, growth curves and E7 mRNA levels were assessed.

RESULTS

The two most active siRNA sequences resulted in a 67% and 71% reduction in E6/E7 mRNA. Fluorescent lamin siRNA was visualized up to 120 h after the initial tumor injection and was evenly distributed throughout the tumors. IHC showed lamin expression to be inhibited by 68% and 75% when compared to controls at 54 and 120 h respectively. In our preliminary therapeutic intervention experiments there was no significant difference in tumor growth between the treatment groups when mice were treated with three daily injections (p=0.41). However, when treated every third day for three injections final tumor volume was less in animals injected with siRNA sequences A (78% reduction; p<0.0001) and G (60% reduction; p=0.005) compared to saline injection. Tumors showed a corresponding decrease in E6/E7 mRNA. Extended treatment with siRNA completely or nearly eradicated tumors in 70% of the animals.

CONCLUSION

Therapeutic siRNA targeting E6/E7 significantly inhibits tumor growth in this mouse model of cervical cancer. Further investigation is needed to determine optimal dosing and route of delivery.

Human papillomavirus causes an angiogenic switch in keratinocytes which is sufficient to alter endothelial cell behavior

One of the requirements for tumor growth is the ability to recruit a blood supply, a process known as angiogenesis. Angiogenesis begins early in the progression of cervical disease from mild to severe dysplasia and on to invasive cancer. We have previously reported that expression of human papillomavirus type 16 E6 and E7 (HPV16 E6E7) proteins in primary foreskin keratinocytes (HFKs) decreases expression of two inhibitors and increases expression of two angiogenic inducers [Toussaint-Smith, E., Donner, D.B., Roman, A., 2004. Expression of human papillomavirus type 16 E6 and E7 oncoproteins in primary foreskin keratinocytes is sufficient to alter the expression of angiogenic factors. Oncogene 23, 2988-2995]. Here we report that HPV-induced early changes in the keratinocyte phenotype are sufficient to alter endothelial cell behavior both in vitro and in vivo. Conditioned media from HPV16 E6E7 expressing HFKs as well as from human cervical keratinocytes containing the intact HPV16 were able to stimulate proliferation and migration of human microvascular endothelial cells. In addition, introduction of the conditioned media into immunocompetent mice using a Matrigel plug model resulted in a clear angiogenic response. These novel data support the hypothesis that HPV proteins contribute not only to the uncontrolled keratinocyte growth seen following HPV infection but also to the angiogenic response needed for tumor formation.

The human papillomavirus type 18 E6 oncoprotein induces Vascular Endothelial Growth Factor 121 (VEGF121) transcription from the promoter through a p53-independent mechanism

Altered angiogenic response is associated with high-grade cervical dysplasia and with invasive squamous carcinoma of the cervix. Vascular Endothelial Growth Factor (VEGF) is one of the most potent inducers of angiogenesis and is up-regulated in carcinoma of the cervix. Infection by high-risk human papillomavirus and persistent expression of viral oncogene E6 are etiologically linked to the development of cervical cancer. E6 is able to immortalize cells and induce malignant transformation by inactivating p53. In cervical cancer, regulation of VEGF expression is poorly described. Thus, we investigated whether E6 oncoprotein could regulate VEGF expression in HPV18-positive cervical cancer-derived HeLa cells harboring a wild-type p53. The alternative splicing of vegf mRNA renders three major isoforms of 121, 165 and 189 amino-acids in humans. We have designed isoform specific real time QRT-PCR assays to quantitate vegf transcripts and VEGF121 was the predominant isoform. Silencing HPV18 E6 mRNA with specific siRNA reduced VEGF121 expression by at least 50% whereas silencing of p53 did not alter its expression. Treatment with cycloheximide did not inhibit E6-induced VEGF121 expression. Collectively, these results suggest that HPV18 E6 oncoprotein contributes to tumor angiogenesis by inducing VEGF transcription from the promoter in a p53-independent manner.

Overexpression of human papillomavirus type 16 oncoproteins enhances hypoxia-inducible factor 1 alpha protein accumulation and vascular endothelial growth factor expression in human cervical carcinoma cells

PURPOSE

Human papillomavirus (HPV)-16 oncoproteins, E6 and E7, are associated with enhanced tumor angiogenesis in human cervical cancers. The purpose of this study was (a) to investigate whether expression of HPV-16 E6 and E7 oncoproteins induces hypoxia-inducible factor 1 alpha (HIF-1 alpha) and vascular endothelial growth factor expression in cervical cancer cells; and (b) to assess the effect of resveratrol on 16 E6- and E7-induced HIF-1 alpha and VEGF gene expression.

EXPERIMENTAL DESIGN

Human cervical cancer cell lines C-33A and HeLa were transiently cotransfected with pSG5-HPV-16 E6 or 16 E7 constructs along with HIF-1 alpha small interfering RNA (siRNA) or nonspecific siRNA. The expression of HIF-1 alpha/VEGF was measured using real-time PCR, Western blot analysis, or ELISA. The in vitro angiogenic activity induced by 16 E6- and E7-transfected cells was examined. The effect of resveratrol on oncoprotein-induced HIF-1 alpha/VEGF expression and in vitro angiogenesis was investigated.

RESULTS

HPV-16 E6- and E7-transfected cervical cancer cells express increased HIF-1 alpha protein and VEGF expression. These stimulatory effects were abrogated by cotransfection with either HIF-1 alpha siRNA or treatment with resveratrol. Blocking extracellular signal-regulated kinase 1/2 (ERK 1/2) and phosphoinositide-3-kinase by PD98059 and LY294002, respectively, abolished 16 E6- and E7-induced HIF-1 alpha and VEGF expression. Functionally, we showed that HPV-16 E6- and E7-transfected cervical cancer cells stimulated in vitro capillary or tubule formation, and these angiogenic effects could be abolished either by cotransfection with HIF-1 alpha siRNA or by treatment with resveratrol.

CONCLUSION

HPV-16 oncoproteins contribute to enhanced angiogenesis in cervical cancer cells via HIF-1 alpha-dependent VEGF expression. Resveratrol suppresses 16 E6- and E7-induced HIF-1 alpha-mediated angiogenic activity and, thus, is a promising chemotherapeutic agent for human cervical cancer.

The expression of epidermal growth factor receptor, vascular endothelial growth factor, matrix metalloproteinase-2, and cyclooxygenase-2 in relation to human papilloma viral load and persistence of human papillomavirus after conization with negative margins

The aim of this study was to investigate the correlations between human papillomavirus (HPV) load and vascular endothelial growth factor (VEGF), epidermal growth factor receptor (EGFR), matrix metalloproteinase-2 (MMP-2), and cyclooxygenase-2 (COX-2), and to identify biomarkers that may predict high-risk HPV clearance or persistence after conization with negative margins. The following samples were analyzed: 77 paraffin-embedded specimens from patients with cervical intraepithelial neoplasia (CIN), including 27 CIN 2 conization specimens and 50 CIN 3 conization specimens. Immunohistochemical analysis was performed with antibodies to VEGF, EGFR, MMP-2, and COX-2. Hybrid capture II testing was used to detect HPV DNA. VEGF expression was significantly associated with HPV load (rho = 0.27186, P = 0.0191), while COX-2 expression was significantly and inversely associated with HPV load (rho = -0.34309, P = 0.0028). In univariate analysis, HPV load (P = 0.0112) and VEGF expression (P = 0.0274) were significantly associated with high-risk HPV clearance or persistence after conization with negative margins. In multiple regression analysis, high viral load (relative light unit/positive control > 500) and positive VEGF expression were significantly associated with high-risk HPV persistence after conization with negative margins (odds ratio [OR]: 9.915, CI: 1.891-51.994; OR: 6.661, CI: 1.208-36.722, respectively). In conclusion, VEGF expression is related to HPV load, while COX-2 expression is inversely related to HPV load, and immunohistochemical analysis of VEGF expression and HPV viral load are a significant and an independent prognostic indicator of high-risk HPV persistence after conization with negative margins.

Association between CD31 expression and histopathologic features in stage IB squamous cell carcinoma of the cervix

This study was undertaken to evaluate the association between the expression of CD31 in the tumor and the histopathologic findings in patients with carcinoma of the cervix. This study included prospectively 30 women, aged 46.6 +/- 10.7 years, with stage IB squamous cell carcinoma of the cervix submitted to radical hysterectomy from November 2001 to September 2002. Samples from the tumor were taken and immunohistochemically evaluated by a monoclonal antibody for CD31. Clinicopathologic characteristics such as stage, tumor size, grade of differentiation, lymphatic vascular space invasion (LVSI), parametrial involvement, and status of pelvic lymph nodes were also recorded. The clinical stage (FIGO) was IB1 in 22 patients (73.3%) and IB2 in 8 patients (26.7%). The expression of CD31 was significantly associated with tumor size and the presence of LVSI, but not with grade of differentiation and vaginal or parametrial involvement (P= 0.03, P= 0.032, P= 0.352, P= 0.208, and P= 0.242, respectively). On univariate analysis, the presence of pelvic lymph node metastasis was influenced by LVSI (P= 0.003) and CD31 expression (P= 0.032). However, on multivariate analysis, the presence of LVSI (P= 0.007) was the only independent predictor of pelvic lymph node metastasis. The CD31 expression in tumor is significantly associated with LVSI and tumor size in patients with early-stage squamous cell carcinoma of the cervix.

Aberrant expression of VEGF-C is related to grade of cervical intraepithelial neoplasia (CIN) and high risk HPV, but does not predict virus clearance after treatment of CIN or prognosis of cervical cancer

AIMS

Increased angiogenesis leads to invasion in cervical cancer. Vascular endothelial growth factors (VEGFs) are involved in angiogenesis, but molecular links to the most important aetiological agent, human papillomavirus (HPV), need clarifying.

MATERIAL/METHODS

Archival samples-150 squamous cell carcinomas (SCCs) and 152 cervical intraepithelial neoplasia (CIN) lesions-were examined immunohistochemically for anti-VEGF-C antibody and for HPV by polymerase chain reaction (PCR). Follow up data were available for all SCC cases, and 67 CIN lesions were monitored with serial PCR to assess HPV clearance/persistence after treatment.

RESULTS

High risk (HR) HPV types were closely associated with CIN (odds ratio, 19.12; 95% confidence interval, 2.31 to 157.81) and SCC (27.25; 3.28 to 226.09). There was a linear increase of VEGF-C expression-weak in CIN1 and intense in CIN3 and SCC (20.49; 8.69 to 48.26). VEGF-C upregulation was a sensitive (93.5%; 95% CI, 90.1% to 96.9%) marker of HR-HPV type (4.70; 2.17 to 10.21), but lost its significance in multivariate regression-p16(INK4a) and survivin were equally strong independent predictors of HR-HPV. Aberrant expression of VEGF-C did not predict clearance/persistence of HR-HPV after treatment of CIN. In cervical cancer, VEGF-C had no prognostic value in univariate or multivariate survival analysis. After adjustment for HR-HPV, FIGO stage, age, and tumour grade, only FIGO stage and age remained independent prognostic predictors.

CONCLUSIONS

VEGF-C is an early marker of cervical carcinogenesis, with linearly increasing expression starting from low grade CIN. VEGF-C expression is closely related to HR-HPV in cervical lesions, probably because of its p53 independent upregulation by the E6 oncoprotein of HR-HPV.

Lymphangiogenesis in human gynaecological cancers

The metastatic spread of tumor cells is responsible for the majority of cancer deaths, and with few exceptions, all cancers can metastasize. Clinical findings have for a long time suggested that by providing a pathway for tumor cell dissemination, tumor-associated lymphatics act as key components of metastatic spread. This is believed to occur principally via pre-existing and possibly also newly formed lymphatics (lymphangiogenesis). Increased expression of vascular endothelial growth factor-C (VEGF-C) and VEGF-D in primary tumors correlates with increased dissemination of tumor cells to regional lymph nodes (LNs) in a variety of human carcinomas. Here we will review the mechanisms of lymphangiogenesis, particularly in the context of metastatic tumor spread, and will critically examine the role of VEGF-C and VEGF-D in this process in gynaecological cancers. Potential anti-lymphangiogenic strategies are also discussed.

Gene Identification by cDNA Arrays in HPV-Positive Cervical Cancer

BACKGROUND

One of the most frequent malignancies in women worldwide is carcinoma of the uterine cervix. High-risk human papillomavirus (HPV) infection is considered the most important etiological factor of uterine cervical cancer. Our aim was to identify novel cellular genes that could potentially act as predictive molecular markers for human cervical cancer by means of cDNA arrays.

METHODS

We used cDNA arrays to examine the expression profiles of six cell lines derived from human cervical cancer, three HPV+ tumor samples and three normal (HPV-) epithelium tissues. Data normalization was performed and the top overexpressed genes were obtained. Hierarchical cluster was performed and, to validate some of the differentially expressed genes between normal and carcinogenic samples, semi-quantitative RT-PCR, in situ hybridization and immunohistochemistry were performed in tissue samples.

RESULTS

Four genes were demonstrated to be consistently overexpressed in invasive cervical cancer biopsies; three novel genes not previously related to cervical cancer: MMP10, Lamc2 and Claudin 1. Moreover, overexpression of IL6 and VEGF was corroborated.

CONCLUSIONS

The identification of characteristic molecular changes in cervical cells by carcinogenesis and HPV infection can lead to a better understanding of cervical cancer. cDNA arrays are beginning to provide new possible molecular markers for prognosis and diagnosis. This technology could eventually help to elucidate the biological differences of the particular mechanisms associated with each different HPV-type infection and those with a poor prognosis.

HPV18 E6 and E7 genes affect cell cycle, pRB and p53 of cervical tumor cells and represent prominent candidates for intervention by use peptide nucleic acids (PNAs)

Approximately 100% of cervical carcinomas are causally linked to infections with high-risk human papillomaviruses (HPVs), whose oncogenicity has been assigned to the continued expression of two early viral genes, E6 and E7. Reversal of the transformed phenotype by inhibiting E6/E7 gene expression therefore provides a suitable goal for tumor therapy. We established an application controlling the E6/E7 expression of the HPV type 18, by using viral gene directed peptide nucleic acids (PNAs). One consequence was the complete change in growth to a stagnated behavior of the HPV 18 positive HeLa-S cells. With flow cytometry, we investigated changes in the cell cycle and expression of the pRB (retinoblastoma) and p53 genes acting as antagonists to E6 and E7. We realized that application of PNAs via intracellular cleavable conjugated peptide carriers mediates specific inhibitory effects and we showed that the combined E6/E7-directed PNA-application mediated a clear morphological change from suspension to adherend state and the cells stopped growth. These data could demonstrate a promising approach for development of new 'anti-gene therapeutics' against papillomavirus-induced human cancers.

Expression of human papillomavirus type 16 E6 and E7 oncoproteins in primary foreskin keratinocytes is sufficient to alter the expression of angiogenic factors

Human papillomavirus (HPV) 16 is involved in causing cervical cancer. The E6 and E7 proteins of HPV 16 immortalize human keratinocytes and this is due, at least in part, to inactivation of the tumor suppressor proteins p53 and pRB. These tumor suppressor proteins also regulate the expression of pro- and antiangiogenic factors by cells. For this reason, experiments were conducted to determine whether the expression of E6 and E7 in primary keratinocytes alters the phenotype of these cells such that they express diminished levels of antiangiogenic factors and/or increased levels of proangiogenic factors. To avoid variances in experimental observations, pools of human foreskin keratinocytes from multiple sources were infected with recombinant retrovirus expressing HPV 16 E6 and E7 or control retrovirus. Gene array analysis, RT-PCR, ELISAs and Western blotting showed that in cells expressing HPV 16 E6 and E7, expression levels of two potent angiogenesis inhibitors, thrombospondin-1 and maspin, were lower compared to controls. Additionally, major angiogenesis inducers, interleukin-8 and vascular endothelial growth factor (VEGF), were increased relative to controls. VEGF can be produced as multiple splice variants, all of which are required for the formation of patent blood vessels. The expression of HPV 16 E6 and E7 in keratinocytes augmented expression of VEGF 121, 145, 165 and 189. These observations show that HPV 16 E6 and E7 alter the phenotype of primary keratinocytes, diminishing expression of inhibitors and increasing expression of inducers of angiogenesis. This altered phenotype may permit keratinocytes infected by HPV 16 to play a role in the progression of cancer by permitting tumors to acquire a blood supply permissive of growth and spread.

Anti-cytokine Ab immune therapy: present status and perspectives

Allergy, autoimmunity and the pathogenesis of some chronic diseases are dependent on host innate and adaptative immune responses. Both responses are associated with abnormal cytokine production within pathologic tissues. Over the past two decades, the availability of purified cytokines and cytokine antibodies (Abs) has prompted a therapeutic approach that aims to supply neutralizing Abs against deleterious cytokines, through either passive immunization (administration of large quantities of high affinity Abs, prepared ex vivo) or active immunization (induction of specific Abs, using immunogenic cytokine derivatives). Both passive and active immunization can safely, transiently and effectively be used, as has been documented by animal experimentation and confirmed by clinical trials. Novel anti-cytokine therapeutic compounds, based on passive Ab immunization, are now available to treat rheumatoid arthritis (RA) and have been shown to help control neoangiogenesis in cancer patients. Clinical trials using Abs to treat allergic disorders are also underway. However, the induction of anti-idiotypic Abs may restrict the long-term use of anti-cytokine immunotherapy using allogenic or humanized/chimeric Abs. We propose that greater consideration should be given to active immunization protocols.

Oncomodulatory signals by regulatory proteins encoded by human cytomegalovirus: a novel role for viral infection in tumor progression

A high frequency of human cytomegalovirus (HCMV) genome and antigens in tumor samples of patients with different malignancies is now well documented, although the causative role for HCMV in the development of the neoplasias remains to be established. HCMV infection can modulate multiple cellular regulatory and signalling pathways in a manner similar to that of oncoproteins of small DNA tumor viruses such as human papilloma virus or adenoviruses. However, in contrast to these DNA tumor viruses, HCMV infection fails to transform susceptible normal human cells. There is now growing evidence that tumor cells with disrupted regulatory and signalling pathways enable HCMV to modulate their properties including stimulation of cell proliferation, survival, invasion, production of angiogenic factors, and immunogenic properties. In contrast to previously suggested "hit and run" transformation we suggest that persistence in tumor cells is essential for HCMV to fully express its oncomodulatory effects. These effects are observed particularly in persistent HCMV infection and are mediated mainly by activity of HCMV regulatory proteins. In persistently HCMV-infected tumor cell lines - a selection of novel, slowly growing virus variants with changes in coding sequences for virus regulatory proteins takes place. As a result, oncomodulatory effects of HCMV infection may lead to a shift to more malignant phenotype of tumor cells contributing to tumor progression.