Diagnosing human papillomaviruses: recent advances

A Recent Advancement in Nanotechnology Approaches for the Treatment of Cervical Cancer

BACKGROUND

Cervical cancer is one of the leading causes of female death, with a mortality rate of over 200,000 per year in developing countries. Despite a decrease in cervical cancer occurrences in developed countries over the last decade, the frequency of the disease in developing nations continues to rise at an alarming rate, particularly when it is linked to the human papillomavirus (HPV). With just a few highly invasive conventional therapies available, there is a clear need for novel treatment options such as nanotechnology-based chemotherapeutic drug delivery.

METHODS

Traditional anticancer therapy is limited by poor drug potency, non-specificity, unwanted side effects, and the development of multiple drug resistance (MDR), leading to a decrease in long-term anticancer therapeutic efficacy. An ideal cancer therapy requires a personalized and specialized medication delivery method capable of eradicating even the last cancer cell responsible for disease recurrence.

RESULTS

Nanotechnology provides effective drug delivery mechanisms, allowing it to serve both therapeutic and diagnostic purposes. Nanotechnology-based formulations are widely used to accurately target the target organ, maintain drug load bioactivity, preferentially accumulate the drug at the target location, and reduce cytotoxicity.

CONCLUSION

The key benefits of this drug delivery are that it improves pharmacological activity, solubility, and bioavailability and reduces toxicity in the target tissue by targeting ligands, allowing for new innovative treatment methods in an area that is desperately required. The goal of this review is to highlight possible research on nanotechnologybased delivery systems for cancer detection and treatment.

Microchips for the diagnosis of cervical cancer

Cancer affects more people than any other disease. About one-third of the world's population is likely to get this diagnosis during their lifetime. Currently, the diagnostic methods for cancer detection are based on visual inspection. The lack of high analytical and clinical specificity and sensitivity makes these methods in many cases inferior to recently developed molecular methods. The increased clinical specificity and sensitivity of these new molecular approaches have great benefits, such as the possibility of implementing the molecular methods in miniaturized systems and enabling easier and faster point-of-care or bedside diagnostics. This chapter provides an introduction to performing clinical trials, screening, and molecular diagnostics against cancer-related markers. In addition, an example of molecular diagnosis of cervical cancer within a microsystem concept will be presented.

Type-specific multiple sequencing primers: a novel strategy for reliable and rapid genotyping of human papillomaviruses by pyrosequencing technology

DNA sequencing is the gold standard method for accurate microbial and viral typing. However, DNA sequencing techniques have been facing limitations in typing of human papillomaviruses when the specimen harbors multiple genotypes and yields nonspecific amplification products, resulting in nonspecific and noninterpretable sequence data. To address these limitations we have developed a type-specific multiple sequencing primer DNA-sequencing method. This new strategy is suitable for sequencing and typing of samples harboring different genotypes (co-infections with multiple genotypes) and yielding nonspecific amplifications, thus eliminating the need for nested polymerase chain reaction (PCR), stringent PCR conditions, and cloning. The new approach has also proved useful for amplicons containing low PCR yield or subdominant types, avoiding reperforming of amplifications. We have applied the multiple sequencing primer method for genotyping of clinically relevant human papillomaviruses in a clinical test panel by using a combined pool of seven type-specific sequencing primers for HPV-6, -11, -16, -18, -31, -33, and -45. Furthermore, we introduced a sequence pattern recognition approach when there was a plurality of genotypes in the sample to facilitate typing of more than one target DNA in the sample. The multiple sequencing primer method has proved to be a multifaceted approach for typing of human papillomaviruses by DNA sequencing technologies.

Facile, comprehensive, high-throughput genotyping of human genital papillomaviruses using spectrally addressable liquid bead microarrays

Human papillomavirus (HPV) is the worldwide cause of carcinoma of the uterine cervix, a cancer that is the second most common neoplasm in women, resulting in nearly 250,000 deaths a year. The magnitude of the risk of cancer after HPV infection, however, is virus type-specific. Over 40 HPV types can infect the genital tract. Comprehensive, high-throughput typing assays for HPV, however, are not currently available. Blending multiplex PCR and multiplex hybridization using spectrally addressable liquid bead microarrays we have developed a high-throughput, fast, single-tube-typing assay capable of simultaneously typing 45 HPV. The overall incidence of HPV in 429 women tested using this new assay was 72.2% for those with squamous intraepithelial lesions, 51.5% for those with atypical squamous cells of undetermined significance and 15.4% for women with normal cytology, respectively. This compared well with the incidence of HPV detected by a parallel non-typing generic high-risk assay. The new assay detected a wide spectrum of HPV types and a high incidence of mixed infections. We believe our assay may find widespread applications in areas requiring virus type-specific information, such as in epidemiological studies, cancer screening programs, monitoring therapeutic interventions, and evaluating the efficacy of HPV vaccine trials.

Parallel nanoliter detection of cancer markers using polymer microchips

A general multipurpose microchip technology platform for point-of-care diagnostics has been developed. Real-time nucleic acid sequence-based amplification (NASBA) for detection of artificial human papilloma virus (HPV) 16 sequences and SiHa cell line samples was successfully performed in cyclic olefin copolymer (COC) microchips, incorporating supply channels and parallel reaction channels. Samples were distributed into 10 parallel reaction channels, and signals were simultaneously detected in 80 nl volumes. With a custom-made optical detection unit, the system reached a sensitivity limit of 10(-6) microM for artificial HPV 16 sequences, and 20 cells microl(-1) for the SiHa cell line. This is comparable to the detection limit of conventional readers, and clinical testing of biological samples in polymer microchips using NASBA is therefore possible.

Prophylactic human papillomavirus vaccines: the beginning of the end of cervical cancer

Persistent infection with one of the oncogenic human papillomavirus (HPV) types is a necessity for the development of cervical cancer. By HPV vaccination, cervical cancer could become a very rare disease. Two types of HPV vaccines can be distinguished: (i) therapeutic vaccines which induce cellular immunity targeted against epithelial cells infected with HPV and (ii) prophylactic vaccines inducing virus-neutralizing antibodies protecting against new but not against established infections. At present, several vaccines have been developed and tested in clinical trials. The vaccines are generally well tolerated and highly immunogenic. The current clinical data indicate that prophylactic vaccines are very effective against new persistent infections and the development of cervical intraepithelial lesions. The protection is type specific. However, the follow-up of the vaccination trials is still short. The effect of HPV vaccines on future cancer incidence will only be known after decades of follow-up. This article will address the status of recently terminated phase II and currently running phase III trials with prophylactic HPV vaccines.

Human papillomavirus and cervical cancer: issues for biobehavioral and psychosocial research

There is now overwhelming evidence that high-risk, sexually transmitted types of human papillomavirus (HPV) are the main causal agent in cervical cancer. Biobehavioral and psychosocial research is uniquely capable of addressing many of the issues raised by HPV and its link with cervical cancer. In this article we review current findings in this area and identify issues for future research. The first of the three sections explores issues associated with the introduction of HPV testing for the detection and management of cervical abnormalities and the impact of growing public awareness of the sexually transmitted nature of cervical cancer. The implications for public understanding of cervical cancer, psychosocial issues associated with screening, and the potential impact on screening uptake are discussed. The second section addresses the role of biobehavioral factors in the persistence and progression of HPV infection as well as possible interventions to minimize the risk of persistence. Finally, primary prevention of HPV is discussed.

PCR detection of human papillomavirus of the mucosa: comparison between MY09/11 and GP5+/6+ primer sets

BACKGROUND AND OBJECTIVES

Human papillomaviruses (HPV) are the causal agent for the development of carcinomas in the cervix uteri and further pathological changes of the skin including mucosa, particularly warts, condylomas and dysplasias. Therefore, we investigated the efficacy of different consensus primers pairs for HPV detection by PCR using brushed samples from the oral cavity in comparison with samples from the cervix uteri.

STUDY DESIGN

In the present study, we used two well-established sets of PCR primers in different combinations for the detection of HPV DNA in 106 non-invasive brush biopsy samples of the oral mucosa and 56 samples from the cervix uteri. Direct sequencing of PCR products in all cases determined HPV genotype and specificity.

RESULTS

Overall, HPV was detected in 69 of 106 oral mucosa samples. HPV specific amplicons were obtained in 35.8% (N = 38) when using GP5+/6+ primers. The positivity rate was increased to 65.1% in a GP5+/6+ auto-nested PCR approach. In contrast, MY9/11 PCR and nested PCR with MY9/11 outer followed by GP5+/6+ inner primers yielded 2.2% and 16.1%, respectively. In gynaecological samples, PCR results were similar independent of the primer combination used. Thus, DNA quality and DNA content could be additional factors influencing the rate of positivity.

CONCLUSION

For oral mucosa samples, auto-nested GP5+/6+ PCR is in our hands the most suitable approach for epidemiological studies because of its high sensitivity, high reliability and reproducibility as well as its relatively simple laboratory procedure.

The boundaries of cellular pathology: how pathologists see their clinical role

There has been much recent public attention on the effects of the practices of cellular pathology on patients and their relatives. It is important to establish clearly pathologists' views about their professional relationships to clinicians and patients. A national postal questionnaire survey was performed to investigate how cellular pathologists perceive their role in clinical practice and whether there are important differences between different groups of pathologists. Responses were received from 773 pathologists, of whom 167 were trainees. On the basis of responses to 25 attitude statements, it appears that the profession shares a core belief that pathologists are clinicians rather than scientists and sees diagnosis as its main clinical responsibility. However, the role that each pathologist feels clear about differs significantly between pathologists, with a stronger consensus over function, responsibility, and professional image than on the clinical practice of pathology, job satisfaction, and the impact of technological change. Academic activities are a minority interest, although academic pathologists express better job satisfaction and more radical views of professional practice. Young trainees are more likely to work in teaching hospitals, to be female, to have trained outside the UK, and to have had experience in other specialties. They have, however, a more restricted view of the clinical role of pathology than accredited pathologists. Most cellular pathologists see themselves as clinicians with a special role in diagnosis, but how this is interpreted and the extent to which pathologists involve themselves in clinical decision-making is inconsistent. This professional dilemma should be addressed by research to obtain more systematic knowledge of the clinical impact of cellular pathology and especially the ill-defined links between diagnosis and clinical decision-making.