EphrinB1: novel microtubule associated protein whose expression affects taxane sensitivity.

Microtubules (MTs) are components of the cytoskeleton made up of polymerized alpha and beta tubulin dimers. MT structure and function must be maintained throughout the cell cycle to ensure proper execution of mitosis and cellular homeostasis. The protein tyrosine phosphatase, PTPN13, localizes to distinct compartments during mitosis and cytokinesis. We have previously demonstrated that the HPV16 E6 oncoprotein binds PTPN13 and leads to its degradation. Thus, we speculated that HPV infection may affect cellular proliferation by altering the localization of a PTPN13 phosphatase substrate, EphrinB1, during mitosis. Here we report that EphrinB1 co-localizes with MTs during all phases of the cell cycle. Specifically, a cleaved, unphosphorylated EphrinB1 fragment directly binds tubulin, while its phosphorylated form lacks MT binding capacity. These findings suggest that EphrinB1 is a novel microtubule associated protein (MAP). Importantly, we show that in the context of HPV16 E6 expression, EphrinB1 affects taxane response in vitro. We speculate that this reflects PTPN13's modulation of EphrinB1 phosphorylation and suggest that EphrinB1 is an important contributor to taxane sensitivity/resistance phenotypes in epithelial cancers. Thus, HPV infection or functional mutations of PTPN13 in non-viral cancers may predict taxane sensitivity.

Theoretical modeling of HPV: QSAR and novodesign with fragment approach.

Structure-activity relationships in a data set of HPV6-E1 helicase ATPase inhibitors were investigated based on two different sets of descriptors. Statistically significant four parameter Quantitative Structure-Activity Relationships (QSAR) models were constructed and validated in both cases (R(2)=0.849; R(2) cv=0.811; F=52.20; s(2)=0.25; N=42). A Fragment based QSAR (FQSAR) approach was applied for developing a fragment-QSAR equation, which enabled the construction of virtual structures for novel ATPase inhibitors with desired or pre-defined activity.

Long-term study of a quadrivalent human papillomavirus vaccine.

BACKGROUND: We present a long-term safety, immunogenicity, and effectiveness study of a quadrivalent human papillomavirus (HPV4) vaccine. METHODS: Sexually naive boys and girls aged 9 to 15 years (N = 1781) were assigned (2:1) to receive HPV4 vaccine or saline placebo at day 1 and months 2 and 6. At month 30, the placebo group (n = 482) received HPV4 vaccine following the same regimen and both cohorts were followed through month 96. Subjects ≥ 16 years were eligible for effectiveness evaluations. The primary objective was to evaluate the long-term anti-HPV6/11/16/18 serological levels. The secondary objective was to estimate vaccine effectiveness against HPV6/11/16/18-related persistent infection or disease. RESULTS: For each of the HPV4 vaccine types, vaccination-induced anti-HPV response persisted through month 96. Among 429 subjects who received HPV4 vaccine at a mean age of 12, none developed HPV6/11/16/18-related disease or persistent infection of ≥ 12 months' duration. Acquisition of new sexual partners (among those ≥ 16 years) was ∼1 per year. Subjects receiving HPV4 vaccine at month 30 (mean age 15 years) had a similar baseline rate of seropositivity to ≥ 1 of the 4 HPV types to those vaccinated at day 1 (mean age 12 years; 1.9% [9 of 474] vs 1.7% [20 of 1157]); however, 4 of the 9 subjects vaccinated at the later age were seropositive to 3 vaccine types, indicating previous HPV exposure. No new significant serious adverse events were observed for 8 years postvaccination in both genders. CONCLUSIONS: When administered to adolescents, the HPV4 vaccine demonstrated durability in clinically effective protection and sustained antibody titers over 8 years.

Novel action modality of the diterpenoid anisomelic acid causes depletion of E6 and E7 viral oncoproteins in HPV-transformed cervical carcinoma cells.

Cervical cancer, the second most common malignancy among women, is mainly caused by human papilloma virus (HPV) infection. In HPV-positive cervical cancer cells, the activity of p53 and the induction of p21 are inhibited by the HPV oncoproteins E6 and E7. Therefore, blocking the activity of E6 and E7 would serve as an important therapeutic target in these cancer cells. In this study, anisomelic acid (AA), a natural compound belonging to the same diterpenoid family of bioactive compounds as taxol, was found to deplete the E6 and E7 proteins in HPV-positive cervical cancer cells. Consequently, p53 and the p53-responsive gene, p21, were dramatically induced, leading to G2/M-phase cell cycle arrest. AA-mediated cell cycle arrest and p21 expression were canceled when p53 was down-regulated by p53-shRNA. AA also induced p53-independent intrinsic apoptosis by depletion of the cellular inhibitor of apoptosis protein 2 (cIAP2) whose proteosomal degradation is inhibited by E6. The in ovo chick embryo chorioallantoic membrane (CAM) assay showed that anisomelic acid inhibited the tumor growth of the cervical cancer SiHa cells. AA is revealed to hold a novel action modality based on specific targeting of the HPV oncoproteins, which restores p53-mediated growth arrest and induces apoptosis by terminating E6-mediated cIAP2 stabilization.

Chemically modified bovine beta-lactoglobulin inhibits human papillomavirus infection.

Previous studies have shown that 3-hydroxyphthalic anhydride-modified bovine beta-lactoglobulin is a promising anti-HIV microbicide candidate. Here we found that this chemically modified protein, designated JB01, exhibited highly potent antiviral activity against infection by human papillomaviruses (HPV), including HPV6, HPV16 and HPV18. Its anti-HPV activity was correlated with the percentage of modified lysine and arginine residues in JB01. This modified milk protein had no cytotoxicity at the concentration of 1 mg/ml, and it is highly stable at room temperature and 37 °C for at least 12 weeks. These results suggest that JB01 has good potential to be developed as an effective, safe and inexpensive antiviral agent for treatment and prevention of HPV infection.

The use of sinecatechins (polyphenon E) ointment for treatment of external genital warts.

INTRODUCTION: Sinecatechins is a standardized extract of green tea leaves, containing a mixture of catechin compounds. The 15% ointment has been approved for the topical treatment of condylomata acuminata (CA), caused by particular human papillomaviruses (HPV), mainly HPV types 6 and 11. OBJECTIVE: To update the use of sinecatechins for treatment of CA and to describe possible mechanisms involved in the mode of action. AREAS COVERED: The clearance rate of wart lesions after treatment with sinecatechins is similar to other topically applied drugs, like imiquimod and podophyllotoxin, but recurrences are seen less frequently after treatment with sinecatechins. The molecular mode of action underlying the clinical efficacy has yet not been characterized, but the following properties are likely to be involved in the regression of genital warts: activation of cellular immune reactions, induction of cell cycle arrest and apoptosis, inhibition of HPV gene expression. EXPERT OPINION: Sinecatechins is a safe and effective treatment option for CA. Due to the variety of molecular activities of catechins the product has great potential for application to other viral and tumor lesions in the future.

Integrating clinical, community, and policy perspectives on human papillomavirus vaccination.

Infection with genital human papillomavirus (HPV) may cause anogenital cancers, oropharyngeal cancers, anogenital warts, and respiratory papillomas. Two prophylactic vaccines (a bivalent and a quadrivalent vaccine) are now licensed and currently in use in a number of countries. Both vaccines prevent infection with HPV-16 and HPV-18, which together cause approximately 70% of cervical cancers, and clinical trials have demonstrated 90%-100% efficacy in preventing precancerous cervical lesions attributable to HPV-16 and HPV-18. One vaccine also prevents HPV-6 and HPV-11, which cause 90% of genital warts. A growing literature describes psychosocial, interpersonal, organizational, and societal factors that influence HPV vaccination acceptability. This review summarizes the current literature and presents an integrated perspective, taking into account these diverse influences. The resulting integrated framework can be used as a heuristic tool for organizing factors at multiple levels to guide intervention development and future research.

[Local application of cidofovir as adjuvant therapy in recurrent laryngeal papillomatosis in children]. / Aplicação local de cidofovir como tratamento adjuvante na papilomatose laríngea recorrente em crianças.

OBJECTIVE: Evaluate the efficacy of local application of cidofovir in association with surgical treatment of recurrent laryngeal papillomatosis in children. STUDY DESIGN: Prospective. METHODS: Fourteen patients, with an average age of 4.7 years and with two or more relapses after surgical treatment, were submitted to resection of the papillomas and injection of 22.5 mg of cidofovir (7.5 mg/ml) in the tissue where the lesions had been removed. After 2 to 3 week intervals, the same dose of cidofovir was repeated two or three times. In the case of relapse, a new cycle of surgery followed by local applications of cidofovir was repeated. Five children presented HPV-6 and five HPV-11, while in four, the type was not determined. RESULTS: Before beginning of the study, patients were submitted, on the average, to 2 operations a year for control of relapses. After treatment with cidofovir, the annual rate for surgery dropped to 1.1 (p = 0.013). The average interval between relapses before beginning of the study was 1.4 months; at the end of the study, the interval reached 4.4 months (p = 0.014). Patients with HPV-6 did not show a significant change in the intervals between relapses after treatment with cidofovir, while 60% of the children with HPV-11 were disease free at the study end. CONCLUSION: Cidofovir was found to be an effective adjuvant in the treatment of recurrent laryngeal papillomatosis in children, when used in the form of local applications in association with surgical resection of the lesions. HPV-11 may be more susceptible to the beneficial effects of cidofovir.

Cidofovir induces an increase in levels of low-risk and high-risk HPV E6.

BACKGROUND: Cidofovir is a nucleoside analogue that is used off-license to treat recurrent respiratory papillomatosis (RRP) caused by HPV6/11. However, the effect of this drug upon low-risk HPV 6/11 gene expression is unknown. METHODS: The expression of E6 was evaluated by RT-PCR in HPV-ve C33A cervical carcinoma cells stably transfected with both low- and high-risk HPV E6 cDNA's and in SiHa (HPV16+ve) cervical carcinoma cells after treatment with 2 doses and durations of exposure to cidofovir. RESULTS: Compared to the vector only transcript, E6 RNA levels showed an 8-fold increase in low-risk and 20-fold increase in high-risk E6-expressing cells. High-risk E6 protein levels were also detected by Western blot in cidofovir-treated C33A Type16 E6-transfected cells. CONCLUSION: These data may indicate a potential rationale for increased risk of genetic instability and thus transformation due to drug-induced increase in the level of E6.

[Isolation, purification and biological activities of Arnebia euchroma glycosaminoglycans].

OBJECTIVE: To study the methods of extraction, isolation, purification and biological activities of Arnebia euchroma glycosaminoglycans (AEG). METHODS: AEG was purified by distilled water extraction, ethanol fractionation, Sephadex column chromatography. The purity and molecular weight and concentration of AEG were measured by HPLC; We divided the experiment into Physiological Saline group and the other eight groups with different doses of AEG, established RT-PRC method to observe the anti-HPV effect after their actions on the verruca tissues. RESULTS: Using HPLC, the group of AEG was divided into two glycosaminoglycans with different molecular weight as 27336 and 1152. Bioassay results showed that AEG had anti-HPV-DNA activity, the lowest effective concentration was 0.781 mg/ml. CONCLUSION: AEG extracted by this method is a mixture with two molecular weight glycosaminoglycans, and has obvious anti-HPV effect.

Baseline demographic characteristics of subjects enrolled in international quadrivalent HPV (types 6/11/16/18) vaccine clinical trials.

BACKGROUND: In Phase II/III trials, administration of quadrivalent human papillomavirus (HPV) (types 6/11/16/18) L1 virus-like-particle vaccine was highly effective in preventing HPV6/11/16/18-related cervical intraepithelial neoplasia and non-invasive cervical cancer in women aged 16-26 years who were naïve to these HPV types at enrollment. However, the makeup and extent of catch-up vaccination programs among young women is unclear, because a proportion of this population will likely already have been exposed to one or more vaccine-HPV-types. OBJECTIVE: Herein we analyze baseline data from the quadrivalent HPV vaccine clinical trial program to investigate variables which may help shape catch-up vaccine implementation policies. METHODS: Female adolescents and young adults aged 16-26 years were randomized into five clinical trials. Baseline data regarding demographics, sexual history, pregnancy history, and other characteristics were collected at enrollment. At the baseline gynecological examination during enrollment, specimens were obtained for Pap testing. Swabs of external genital, lateral vaginal, and cervical sites for HPV polymerase chain reaction (PCR) testing were taken, and serum samples were obtained for HPV serology testing. Regional analyses of data were conducted. RESULTS: Overall, 72% of subjects enrolled worldwide were naïve by both serology and PCR to all four vaccine HPV types. Few subjects were seropositive and/or PCR positive for more than two vaccine-related HPV types. Of all subjects with HSIL at enrollment, 78% were positive to at least one vaccine-related HPV type at enrollment. Regional differences in HPV and STD prevalence were evident. Study limitations included under-representation of women with >/=4 sexual partners and possible underestimation of prior HPV exposure. CONCLUSIONS: Our findings demonstrate that sexually active 16-26 year-old women with

Sulfated K5 Escherichia coli polysaccharide derivatives as wide-range inhibitors of genital types of human papillomavirus.

Genital human papillomaviruses (HPV) represent the most common sexually transmitted agents and are classified into low or high risk by their propensity to cause genital warts or cervical cancer, respectively. Topical microbicides against HPV may be a useful adjunct to the newly licensed HPV vaccine. A main objective in the development of novel microbicides is to block HPV entry into epithelial cells through cell surface heparan sulfate proteoglycans. In this study, selective chemical modification of the Escherichia coli K5 capsular polysaccharide was integrated with innovative biochemical and biological assays to prepare a collection of sulfated K5 derivatives with a backbone structure resembling the heparin/heparan biosynthetic precursor and to test them for their anti-HPV activity. Surface plasmon resonance assays revealed that O-sulfated K5 with a high degree of sulfation [K5-OS(H)] and N,O-sulfated K5 with a high [K5-N,OS(H)] or low [K5-N,OS(L)] sulfation degree, but not unmodified K5, N-sulfated K5, and O-sulfated K5 with low levels of sulfation, prevented the interaction between HPV-16 pseudovirions and immobilized heparin. In cell-based assays, K5-OS(H), K5-N,OS(H), and K5-N,OS(L) inhibited HPV-16, HPV-18, and HPV-6 pseudovirion infection. Their 50% inhibitory concentration was between 0.1 and 0.9 mug/ml, without evidence of cytotoxicity. These findings provide insights into the design of novel, safe, and broad-spectrum microbicides against genital HPV infections.

Effects of cidofovir on a novel cell-based test system for recurrent respiratory papillomatosis.

BACKGROUND: Cidofovir has been reported to have activity against human papillomavirus (HPV) type 16, but no laboratory studies have been performed on HPV type 6, the main cause of recurrent respiratory papillomatosis (RRP). METHODS: HPV6b E6 cDNA-based C33A (non-HPV cervical carcinoma) cell line was produced. Two different doses of cidofovir were applied to parent C33A, C33AT6E6, and C33AT16E6 (HPV 16). Growth and flow cytometry analysis were performed. RESULTS: Polymerase chain reaction confirmed HPV6 E6 expression in C33AT6E6 cells. High-dose cidofovir was found to be toxic to all cell lines. Low-dose exposure was found to be toxic to C33AT16E6 cells at 3 days, whereas C33A and C33AT6E6 showed minimal toxicity at 6 days and earlier recovery following drug withdrawal. CONCLUSIONS: Cidofovir showed nonspecific toxicity against all 3 cell lines tested. HPV16 E6 expressing cells were more sensitive than parent or HPV6 E6 expressing cells. Cidofovir has no selective advantage for the RRP-related HPV6 E6 expressing cell line.

Indications and efficacy of the human papillomavirus vaccine.

In the United States, there are 11,150 cases and 3670 deaths projected due to invasive cervical cancer for 2007. Approximately 500,000 new cases and 274,000 deaths will occur in women throughout the world. Human papillomavirus (HPV) has been designated by the World Health Organization (WHO) as a "necessary cause" of cervical cancer. There are 6.2 million new cases of HPV diagnosed each year. In addition to cervical cancer, the virus has also been implicated in vaginal, vulvar, penile, anal, and head and neck cancers. Current methods for prevention of cervical cancer include Pap smears, HPV testing, ablative procedures, cervical conization, and hysterectomy. These are costly as well as invasive. The HPV vaccine is the most recent breakthrough for the prevention of cervical cancer. The quadrivalent HPV vaccine (Gardasil) covers types 6, 11, 16, & 18. The bivalent vaccine (Cervarix) covers types 16 & 18, and is expected to come out in the early part of 2007. Approximately 70% of cervical cancer is caused by HPV types 16 & 18. HPV types 6 &11 are responsible for 90% of anogenital warts. Females of ages 11-12 and those prior to their sexual debut should be vaccinated, with all females in the age range of 9-26 also eligible. This vaccination strategy can prevent the above HPV infections, cervical dysplasia, and possibly cervical cancer.