Anogenital neoplasia in AIDS

Human Papillomavirus 16 E5 Inhibits Interferon Signaling and Supports Episomal Viral Maintenance

Human papillomaviruses (HPVs) infect keratinocytes of stratified epithelia. Long-term persistence of infection is a critical risk factor for the development of HPV-induced malignancies. Through the actions of its oncogenes, HPV evades host immune responses to facilitate its productive life cycle. In this work, we discovered a previously unknown function of the HPV16 E5 oncoprotein in the suppression of interferon (IFN) responses. This suppression is focused on keratinocyte-specific IFN-κ and is mediated through E5-induced changes in growth factor signaling pathways, as identified through phosphoproteomics analysis. The loss of E5 in keratinocytes maintaining the complete HPV16 genome results in the derepression of IFNK transcription and subsequent JAK/STAT-dependent upregulation of several IFN-stimulated genes (ISGs) at both the mRNA and protein levels. We also established a link between the loss of E5 and the subsequent loss of genome maintenance and stability, resulting in increased genome integration.IMPORTANCE Persistent human papillomavirus infections can cause a variety of significant cancers. The ability of HPV to persist depends on evasion of the host immune system. In this study, we show that the HPV16 E5 protein can suppress an important aspect of the host immune response. In addition, we find that the E5 protein is important for helping the virus avoid integration into the host genome, which is a frequent step along the pathway to cancer development.

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.

Benign and malignant neoplasias in 261 necropsies for HIV-positive patients in the period of 1989 to 2008

Considering that there are some studies with autopsies from AIDS describing only malignant neoplasias and that changes can occur after the introduction of Highly Active Antiretroviral Therapy (HAART), our objectives were to analyze the frequency of benign and malignant neoplasms in AIDS patients in the periods of both pre- and post-HAART. This is a retrospective study with 261 autopsies of HIV-positive patients between 1989 and 2008 in Uberaba, Brazil. Sixty-six neoplasms were found (39 benign, 21 malignant and six premalignant) in 58 patients. The most frequent malignant neoplasms were lymphoid, in 2.7% (four Non-Hodgkin lymphoma, one Hodgkin, one multiple myeloma and one plasmablastic plasmacytoma), and Kaposi's Sarcoma, in 2.3% (six cases). The most frequent benign neoplasms were hepatic hemangiomas in 11 (4.2%) of 261 cases and uterine leiomyoma in 11 (15.7%) of 70 woman. In the pre-HAART period eight (9.8%) benign neoplasias and four (4.9%) malignant occurred in 82 patients; in the post-HAART period, 29 (16.2%) benign and 17 (9.5%) malignant were present; however, the differences were not significant. We conclude that the introduction of HAART in our region doesn't look to have modified the frequency of neoplasms occurring in patients with HIV.

Heat shock fusion protein-based immunotherapy for treatment of cervical intraepithelial neoplasia III

OBJECTIVES

SGN-00101 (HspE7, Nventa, San Diego, CA) is a novel therapeutic vaccine consisting of a fusion protein containing an M. bovis BCG heat shock protein (Hsp65) covalently linked to the entire sequence of HPV 16 E7. This trial was designed to evaluate the efficacy and toxicities of HspE7 in women with CIN III.

METHODS

HIV (-) women with biopsy-proven CIN III were eligible. Two cohorts were accrued; one cohort to establish efficacy and a second cohort with a longer follow-up period to improve the precision of the trial to estimate response rates. Each patient underwent 3 monthly subcutaneous vaccinations with 500 microg of HspE7 followed by monthly colposcopic follow-up for 1 month in cohort 1 and an extended observation period (2 months) in cohort 2. All patients then underwent a LEEP or cone biopsy of the cervix. A complete pathologic response (pCR) was defined as no evidence of CIN or CIN I (only HPV changes). A partial response (PR) was defined as colposcopic lesion regression of >50% in size. Cervicovaginal lavage samples were obtained at each visit for HPV typing using MY09/ MY11 HPV PCR.

RESULTS

Seventy-two patients were registered and screened, of whom 64 were eligible. Fifty-eight patients completed the trial and were evaluable (31 in cohort 1, 27 in cohort 2). There were no significant epidemiologic or HPV type differences between the 2 cohorts so responses were combined for analysis. Of the 58 evaluable patients, 13 (22.5%) had a pCR; 32 (55%) had a PR and 11 (19%) had stable disease. Two (3.5%) patients in cohort 2 had microinvasive disease and were defined as progressive disease. Thirty-three of 58 (57%) of the patients were infected with HPV 16 prior to vaccination or in subsequent visits. There was no significant difference in regression in women infected with HPV 16 compared to those without HPV 16 infection (88% vs. 70%; p=0.12). Women who had a previous LEEP or ablation for CIN were 2.7 times more likely to have a complete response compared to patients without previous treatment, although the difference was not statistically significant (95% CI for rate ratio: 0.95-6.19, p=0.10). At a cellular level, there was a significant association between local inflammation and response; lower grade of lesional inflammation correlated with a response to HspE7 (p=0.04 using Wilcoxon rank sum test).

CONCLUSIONS

HspE7 appeared to demonstrate activity in women with CIN III and met a priori assumptions for efficacy; however, it is unclear whether this response was due to natural regression rather than treatment effect. HspE7, which targets the HPV 16 E7 oncoprotein, had efficacy in patients infected with HPV types other than 16, suggesting cross-reactivity. A larger randomized, controlled trial is needed to better define efficacy and to identify subsets of women most likely to benefit from immunotherapy.

[Human papilloma virus-induced disease in HIV-positive patients]

Since the introduction of highly active antiretroviral therapy (HAART), opportunistic infections by bacteria and fungi have been reduced in human immunodeficiency virus (HIV)-positive patients. However, diseases caused by human papilloma virus (HPV) have become more frequent despite HAART. There is an increased incidence of anal and cervical carcinomas, their precancerous lesions such as anal/cervical intraepithelial neoplasia, and condylomas and oral warts. In order to prevent anal carcinomas, HIV-positive patients should receive proctoscopic examinations regularly. The examination should include anoscopy and smears for cytology and HPV polymerase chain reaction.

The impact of highly active antiretroviral therapy on the incidence and outcomes of AIDS-defining cancers in Southern Alberta

OBJECTIVES

To determine the impact of highly active antiretroviral therapy (HAART) on the incidence and outcomes of Kaposi's sarcoma (KS), non-Hodgkin's lymphoma (NHL) and invasive cervical cancer/dysplasia in a well-defined geographical HIV-infected population between 1984 and 2005.

METHODS

A clinic database search, chart review and verification with public health records were undertaken for all AIDS-defining cancers diagnosed in Southern Alberta before and after the introduction of HAART.

RESULTS

A total of 2,137 patients with 9,265 person-years of HIV follow-up care were reviewed. One hundred and forty-three cases of KS, 64 cases of NHL and 11 cases of invasive cervical cancer/dysplasia were identified. KS and NHL together accounted for 15% of clinical presentations with an AIDS-defining illness that led to the HIV diagnosis. Following the introduction of HAART, the reduced number of severely immunocompromised patients was associated with 92 and 84% reductions in new diagnoses of KS and NHL, respectively, which were seen mainly in clinic patients declining or failing HAART. Crude reductions of 94 and 65% in mortality from KS and NHL, respectively, were also seen. The prevalences of KS, NHL and invasive cervical cancer/dysplasia have recently stabilized at 3, 1 and 5% of the population, respectively.

CONCLUSIONS

The introduction of HAART has dramatically reduced the incidence of KS and NHL and improved survival from these cancers for most patients in HIV care. However, patients still present with KS and NHL leading to their HIV diagnosis.

High prevalence of human papillomavirus infections in urine samples from human immunodeficiency virus-infected men

Infection with human immunodeficiency virus (HIV) and the resulting immunosuppression are associated with an increased risk for human papillomavirus (HPV) persistence and related malignancies. In the present study we investigated the prevalence of HPV in urine samples from 104 HIV-infected men with low CD4+ cell counts (<100 per mm(3)) and 115 urine samples from HIV-negative men. A high prevalence of HPV DNA (39.4%) was found in the HIV patients. Most of the HPV types were high risk (81.4%), with HPV 52 as the most prevalent type (12.5%), followed by HPV 18 (6.7%), HPV 35 (5.8%), and HPV 70 (4.8%). Multiple HPV genotypes were observed in 17 (41%) of the 41 HPV- and HIV-positive men. In contrast, only 11 (9.6%) HPV DNA-positive cases were observed among the 115 HIV-uninfected men, and 3 (27.3%) contained multiple genotypes. Quantitative analyses indicated that the HPV viral load, as measured in urine samples, is significantly higher in HIV-positive men compared to HIV-negative men. In the present study we show that urine samples are useful for detecting HPV DNA, there is a high prevalence of HPV in HIV-positive men, and the HPV viral load is substantially higher in HIV-positive than in HIV-negative men. More studies are needed to evaluate the risk and natural development of HPV-related malignancies in HIV-positive men.

Molecular mechanisms of the 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced inverted U-shaped dose responsiveness in anchorage independent growth and cell proliferation of human breast epithelial cells with stem cell characteristics

Although 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has a variety of carcinogenic and noncarcinogenic effects in experimental animals, its role in human carcinogenicity remain controversial. A simian virus 40-immortalized cell line from normal human breast epithelial cells with stem cells and luminal characteristics (M13SV1) was used to study whether TCDD can induce AIG positive colony formation and cause increased cell numbers in a inverted U-shaped dose-response manner. TCDD activated Akt, ERK2, and increased the expression of CYP1A1, PAI-2, IL-lb mRNA, and ERK2 protein levels. TCDD was able to increased phosphorylation and expression of ERK2 in same dose-response manner as AIG positive colony formation. Thus, TCDD induced tumorigenicity in M13SV1, possibly through the phosphorylation of ERK2 and/or Akt. Further, cDNA microarray with 7448 sequence-verified clones was used to profile various gene expression patterns after treatment of TCDD. Three clear patterns could be delineated: genes that were dose-dependently up-regulated, genes expressed in either U-shape and/or inverted U-shape. The fact that these genes are intrinsically related to breast epithelial cell proliferation and survival clearly suggests that they may be involved in the TCDD-induced breast tumorigenesis.

Human papillomavirus-related cervical and anal disease in HIV-infected individuals in the era of highly active antiretroviral therapy

HIV-infected men who have sex with men remain at high risk of developing anal cancer despite the widespread use of highly active antiretroviral therapy (HAART). In HIV-infected women, however, there is some evidence that HAART may be associated with regression of human papillomavirus (HPV)-related cervical disease. So far, epidemiologic data provided by cancer registries have shown no reduction in the incidence of cervical and anal cancer in patients with HIV infection since the initiation of HAART in 1996. Recent data suggest that HPV infection occurs in the anal canal of immunocompromised patients, as an opportunistic infection, in the absence of receptive anal intercourse. Taken together, these lines of evidence support the need for developing anal and cervical cancer screening programs for patients with HIV, whether untreated or on HAART.

Emerging human papillomavirus vaccines

Human papillomavirus (HPV) infections are a leading cause of virus-associated cancers of the anogenital, oropharyneal and cutaneous epithelium. The most prevalent of these is cervical cancer, which is responsible for approximately 500,000 deaths annually worldwide. A group of about 15 serologically unrelated 'high-risk' HPV types are responsible for almost all HPV-associated cancers. Prevention of papillomavirus infection can be achieved by induction of capsid-specific neutralising antibodies in preclinical animal papillomavirus models and in recent human clinical trials. High titres of conformationally-dependent, type-specific HPV-neutralising antibodies are triggered by HPV virus-like particle (VLP) vaccines. Overcoming the problems of type-specificity of the responses to these VLP vaccines is a potentially important area of current HPV vaccine research, with an emphasis on induction of more broadly cross-protective neutralising responses. Viral oncogenes E6 and E7 are continuously present in HPV-associated cancers and are prime targets for HPV therapeutic vaccines. A variety of approaches are being tested in therapeutic vaccine clinical trials and in various preclinical animal papillomavirus models for efficacy. Approaches include genetic vaccines, recombinant virus vaccines, dendritic cell-based strategies, immunomodulatory strategies and various combination strategies to maximise cell-mediated immunity to papillomavirus proteins present in HPV infections and cancers. The success of preventive HPV VLP vaccines in clinical trials is clear. However, current therapeutic vaccine trials are less effective with respect to disease clearance. Nevertheless, a series of combination approaches have shown significant therapeutic enhancement in preclinical papillomavirus models and await testing in patient populations to determine the most effective strategy. There is much encouragement that HPV vaccines will be the most effective approach to prevention and cure of infections caused by this group of viruses, which re-present a significant human pathogen.