Worldwide Impact of the Human Papillomavirus Vaccine

A new arylbenzofuran derivative functions as an anti-tumour agent by inducing DNA damage and inhibiting PARP activity

We previously reported that 7-hydroxy-5, 4'-dimethoxy-2-arylbenzofuran (HDAB) purified from Livistona chinensis is a key active agent. The present study investigated the function and molecular mechanism of HDAB. HDAB treatment of cervical cancer cells resulted in S phase arrest and apoptosis, together with cyclin A2 and CDK2 upregulation. Cyclin A2 siRNA and a CDK inhibitor efficiently relieved S phase arrest but increased the apoptosis rate. Mechanistic studies revealed that HDAB treatment significantly increased DNA strand breaks in an alkaline comet assay and induced ATM, CHK1, CHK2 and H2A.X phosphorylation. Wortmannin (a broad inhibitor of PIKKs) and CGK733 (a specific ATM inhibitor), but not LY294002 (a phosphatidylinositol 3-kinase inhibitor) or NU7026 (a DNA-PK specific inhibitor), prevented H2A.X phosphorylation and γH2A.X-positive foci formation in the nuclei, reversed S phase arrest and promoted the HDAB-induced apoptosis, suggesting that HDAB is a DNA damaging agent that can activate the ATM-dependent DNA repair response, thereby contributing to cell cycle arrest. In addition, molecular docking and in vitro activity assays revealed that HDAB can correctly dock into the hydrophobic pocket of PARP-1 and suppress PARP-1 ADP-ribosylation activity. Thus, the results indicated that HDAB can function as an anti-cancer agent by inducing DNA damage and inhibiting PARP activity.

Development of an IP-Free Biotechnology Platform for Constitutive Production of HPV16 L1 Capsid Protein Using the Pichia pastoris PGK1 Promoter

The human papillomavirus (HPV) L1 major capsid protein, which forms the basis of the currently available vaccines against cervical cancer, self-assembles into virus-like particles (VLPs) when expressed heterologously. We report the development of a biotechnology platform for HPV16 L1 protein expression based on the constitutive PGK1 promoter (P_PGK1) from the methylotrophic yeast Pichia pastoris. The L1 gene was cloned under regulation of P_PGK1 into pPGKΔ3 expression vector to achieve intracellular expression. In parallel, secretion of the L1 protein was obtained through the use of an alternative vector called pPGKΔ3α, in which a codon optimized α-factor signal sequence was inserted. We devised a work-flow based on the detection of the L1 protein by dot blot, colony blot, and western blot to classify the positive clones. Finally, intracellular HPV VLPs assembly was demonstrated for the first time in yeast cells. This study opens up perspectives for the establishment of an innovative platform for the production of HPV VLPs or other viral antigens for vaccination purposes, based on constitutive expression in P. pastoris.

Regression of human papillomavirus intraepithelial lesions is induced by MVA E2 therapeutic vaccine

Human papilloma viruses can induce warts, condylomas, and other intraepithelial cervical lesions that can progress to cancer. Cervical cancer is a serious problem in developing countries because early detection is difficult, and thus proper early treatment is many times missing. In this phase III clinical trial, we evaluated the potential use of MVA E2 recombinant vaccinia virus to treat intraepithelial lesions associated with papillomavirus infection. A total of 1176 female and 180 male patients with intraepithelial lesions were studied. They were injected with 10(7) MVA E2 virus particles directly into their uterus, urethra, vulva, or anus. Patients were monitored by colposcopy and cytology. Immune response was determined by measuring the antibody titer against MVA E2 virus and by analyzing the cytotoxic activity against cancer cells bearing papillomavirus DNA. Papillomavirus was determined by the Hybrid Capture method or by polymerase chain reaction analysis. By histology, 1051 (89.3%) female patients showed complete elimination of lesions after treatment with MVA E2. In 28 (2.4%) female patients, the lesion was reduced to CIN 1. Another 97 (8.3%) female patients presented isolated koilocytes after treatment. In men, all lesions were completely eliminated. All MVA E2-treated patients developed antibodies against the MVA E2 vaccine and generated a specific cytotoxic response against papilloma-transformed cells. Papillomavirus DNA was not detected after treatment in 83% of total patients treated. MVA E2 did not generate any apparent side effects. These data suggest that therapeutic vaccination with MVA E2 vaccine is an excellent candidate to stimulate the immune system and generate regression in intraepithelial lesions when applied locally.

Improving global access to new vaccines: intellectual property, technology transfer, and regulatory pathways

The 2012 World Health Assembly Global Vaccine Action Plan called for global access to new vaccines within 5 years of licensure. Current approaches have proven insufficient to achieve sustainable vaccine pricing within such a timeline. Paralleling the successful strategy of generic competition to bring down drug prices, a clear consensus is emerging that market entry of multiple suppliers is a critical factor in expeditiously bringing down prices of new vaccines. In this context, key target objectives for improving access to new vaccines include overcoming intellectual property obstacles, streamlining regulatory pathways for biosimilar vaccines, and reducing market entry timelines for developing-country vaccine manufacturers by transfer of technology and know-how. I propose an intellectual property, technology, and know-how bank as a new approach to facilitate widespread access to new vaccines in low- and middle-income countries by efficient transfer of patented vaccine technologies to multiple developing-country vaccine manufacturers.

The role of human papilloma virus (HPV) infection in non-anogenital cancer and the promise of immunotherapy: a review

Over the past 30 years, human papilloma virus (HPV) has been shown to play a role in the development of various cancers. Most notably, HPV has been linked to malignant progression in neoplasms of the anogenital region. However, high-risk HPV has also been suggested to play a significant role in the development of cancers in other anatomic locations, such as the head and neck, lung, breast and bladder. In 2006, the first vaccine for HPV, Gardasil, was approved for the prevention of subtypes 6, 11, 16 and 18. A few years later, Cevarix was approved for the prevention of subtypes 16 and 18, the HPV subtypes most frequently implicated in malignant progression. Although increased awareness and vaccination could drastically decrease the incidence of HPV-positive cancers, these approaches do not benefit patients who have already contracted HPV and developed cancer as a result. For this reason, researchers need to continue developing treatment modalities, such as targeted immunotherapies, for HPV-positive lesions. Here, we review the potential evidence linking HPV infection with the development of non-anogenital cancers and the potential role of immunotherapy in the prevention and eradication of HPV infection and its oncogenic sequela.

Cervical HPV Infection in Female Sex Workers: A Global Perspective

Introduction:

Approximately 291 million women worldwide are HPV DNA carriers. Studies have indicated that having multiple sexual partners may lead to higher HPV transmission. Thus female sex workers (FSWs) may be at greater risk of infection compared to the general population. Herein we review publications with data on FSW cervical HPV test results. We also examine variations of HPV prevalence and risk behaviors by region. Knowledge of prevalent HPV types in FSWs may lead to improved prevention measures and assist in understanding vaccination in high-risk groups.

Methods:

We conducted a review of the literature by searching PUBMED using the terms “prostitution” or “female sex workers”, “human papillomavirus” or “HPV”, and “prevalence” or “PCR” to find articles. We excluded studies without HPV testing or HPV type specific results, or unconventional HPV testing.

Results:

A total of 35 peer-reviewed publications were included in our review. High risk HPV types 16 and 18 ranged from 1.1-38.9‰ in prevalence. In addition to high-risk HPV types, newer studies reported non-carcinogenic HPV types also of high prevalence. The most prevalent HPV types reported among FSWs included HPV 6 (11.5%), 16 (38.9%), 18 (23.1%), 31 (28.4%), 52 (32.7%), and 58 (26.0%).

Conclusions:

Female sex workers have an overall high prevalence of HPV infection of high-risk types as evident through various testing methods. FSWs are thought to be at increased risk of cervical cancer because of high HPV exposure. This highlights the need for HPV and cervical prevention campaigns tailored to FSWs.

Cancer in developing countries: the next most preventable pandemic. The global problem of cancer

Cancer is a global problem that accounts for almost 13% of deaths worldwide, a number similar to the 7 million deaths each year from HIV/AIDS, TB and malaria combined According to Globocan it is estimated that by 2020, there will be between 15 and 17 million new cases of cancer every year, 60% of which will be in developing countries. Moreover, the survival rates in these regions are often half those of developed countries. However, cancer is potentially the most preventable disease; with current resources, one-third of tumors could be preventable, and another one-third of newly diagnosed cancer patients could experience increased survival or early-stage detection. There have been proposed several strategies and programs to ameliorate cancer prevention and treatment in less developed countries. If all these proposed strategies are taken into consideration, worldwide cancer care, control and survival in low-income countries may improve in the years to come.

The effectiveness of Carraguard, a vaginal microbicide, in protecting women against high-risk human papillomavirus infection

BACKGROUND

A randomised, double-blind, placebo-controlled trial found the vaginal microbicide Carraguard unable to prevent HIV infection. A substudy assessed the association of genital high-risk human papillomavirus (HR-HPV) in women at study end with Carraguard use.

METHODS

Participants received Carraguard gel or placebo plus condoms, and were instructed to use gel plus condoms during each act of vaginal intercourse. HR-HPV detection on cervical samples from 1,723 women was by Digene Hybrid Capture 2 analysis. Poisson regression analysis assessed the prevalence of genital HR-HPV for individuals receiving Carraguard relative to individuals receiving placebo.

RESULTS

In the Carraguard arm (n=875) the end trial unadjusted HR-HPV prevalence was 23.5% (95% CI 20.8-26.3) and 23.0% (95% CI 20.2-25.8) in placebo arm (n=843). Significant risk factors for HR-HPV infection were younger age, being single, an abnormal pap smear, multiple sexual partners and promiscuous behaviour without the use of a condom. There were 348 compliant women (174 Carraguard, 174 placebo users), with relatively high adherence to gel use, who inserted 80% of their opened, returned applicators of test product with the proportion of applicator insertions to sex acts >30%. After adjusting for risk factors, these compliant Carraguard users were 0.62 as likely to be classified HR-HPV positive (95% CI 0.41-0.94) as compliant placebo users.

CONCLUSIONS

The prevalence of HR-HPV infection was lower in compliant Carraguard users than compliant placebo users. To our knowledge, this is the first report showing a negative association of HPV infection with a vaginal microbicide.

Human papillomavirus vaccination in the resourced and resource-constrained world

Human papillomavirus has been established as the causal agent for cervical cancer. The identification of a clear cause presents an unparalleled opportunity for cancer control. As such, the development of prophylactic human papillomavirus vaccines has been rightly hailed as one of the significant scientific triumphs of the past 20 years. This story of scientific triumph over disease, however, is not yet complete. The fruit of scientific labour must be delivered to the people in order to fulfil the underlying intent of the research (i.e. to prevent cancer and save lives). The success of a vaccination programme, however, does not depend on the biological efficacy of the vaccine alone. Various other local factors, such as poverty, gender inequality, cultural traditions, or religious beliefs, can significantly constrain the success of any vaccination programme. In this chapter, we provide an overview of how the human papillomavirus vaccine works and its global uptake, as well as, how variations in local contexts can affect the successful implementation of a vaccination programme. Other factors besides vaccine costs also need serious attention. With better understanding of such factors, policy makers and medical health professionals will be better equipped to make informed decisions to maximise the potential benefits of the human papillomavirus vaccines for the most number of people in individual countries.

Challenges of cancer control in developing countries: current status and future perspective

Cancer is a global problem accounting for almost 13% of all deaths worldwide. This equates to over 7 million people a year, more than is caused by HIV/AIDS, TB and malaria combined. Now is the time to strengthen the health systems of developing countries to deal with cancer, to avoid a future crisis similar to the HIV/AIDS pandemic. In this article we discuss the current state of cancer in the developing world, how we need to advocate for a change in cancer control policy with the governments of developing nations/transnational governmental bodies (e.g., the UN and WHO etc) and how we think cancer care could be improved in developing countries. We feel the only way to overcome the growing burden of cancer in the developing world is working in partnership with, nongovernmental organizations, international nongovernmental organizations, transnational governmental bodies and governmental bodies.

Lifestyle and cancer risk

The main behavioural and environmental risk factors for cancer mortality in the world are related to diet and physical inactivity, use of addictive substances, sexual and reproductive health, exposure to air pollution and use of contaminated needles. The population attributable fraction for all cancer sites worldwide considering the joint effect of these factors is about 35% (34 % for low-and middle-income countries and 37% for high-income countries). Seventy-one percent(71%) of lung cancer deaths are caused by tobacco use (lung cancer is the leading cause of cancer death globally). The combined effects of tobacco use, low fruit and vegetable intake, urban air pollution, and indoor smoke from household use of solid fuels cause 76% of lung cancer deaths. Exposure to these behavioural and environmental factors is preventable; modifications in lifestyle could have a large impact in reducing the cancer burden worldwide (WHO, 2009). The evidence of association between lifestyle factors and cancer, as well as the main international recommendations for prevention are briefly reviewed and commented upon here.

Cancer trends and incidence and mortality patterns in Turkey

Cancer incidence and mortality rates have been increasing in Turkey as most of the developing countries. Besides socioeconomic factors, one of the most prominent attributes of developing countries is the dissimilarity of their age-dependent demographic structure. In Turkey, cancer incidence rates rise due to individual and environmental risk factors as well as due to the improvement in the registry system and to increase in access to health services. According to the data retrieved from the Ministry of Health Department of Cancer Control database cancer incidence rates increased between 2002 and 2005. Incidence rates rose from 133.78 per 100 thousand in 2002 to 173.85 per 100 thousand in 2005. Between 2002 and 2005 the average growth rate of increase for men comes about 9.7%, which is higher than 8.6% for women leading to the widening of incidence gap between man and women. First five frequent cancer types in Turkey are lung (30.13), prostate (24.33), skin (18.91), breast (17.96), stomach (9.92) cancer with an incidence of per 100 thousand. Cancer incidence growth rates for men exceed the cancer incidence growth rate for women. This gap is resulting mainly from lung cancer incidence which is much higher for men. Further extension of the nationwide cancer screening and prevention programs will result in improvement of cancer control.