Detection of human papillomavirus in vulval carcinoma using semi-nested PCR and restriction enzyme typing: a rapid and sensitive technique

Mate-Pair Sequencing as a Powerful Clinical Tool for the Characterization of Cancers with a DNA Viral Etiology

DNA viruses are known to be associated with a variety of different cancers. Human papillomaviruses (HPV) are a family of viruses and several of its sub-types are classified as high-risk HPVs as they are found to be associated with the development of a number of different cancers. Almost all cervical cancers appear to be driven by HPV infection and HPV is also found in most cancers of the anus and at least half the cancers of the vulva, penis and vagina, and increasingly found in one sub-type of head and neck cancers namely oropharyngeal squamous cell carcinoma. Our understanding of HPVs role in cancer development comes from extensive studies done on cervical cancer and it has just been assumed that HPV plays an identical role in the development of all other cancers arising in the presence of HPV sequences, although this has not been proven. Most invasive cervical cancers have the HPV genome integrated into one or more sites within the human genome. One powerful tool to examine all the sites of HPV integration in a cancer but that also provides a comprehensive view of genomic alterations in that cancer is the use of next generation sequencing of mate-pair libraries produced from the DNA isolated. We will describe how this powerful technology can provide important information about the genomic organization within an individual cancer genome, and how this has demonstrated that HPVs role in oropharyngeal squamous cell carcinoma is distinct from that in cervical cancer. We will also describe why the sequencing of mate-pair libraries could be a powerful clinical tool for the management of patients with a DNA viral etiology and how this could quickly transform the care of these patients.

Oral and genital HPV genotypic concordance between sexual partners

OBJECTIVES

The aim of this study was to verify human papillomavirus (HPV) transmission and genotype concordance among heterosexual couples.

MATERIALS AND METHODS

Thirty-one married couples were evaluated. All male subjects presented with clinically diagnosed HPV-related malignant or potentially malignant lesions and underwent peniscopy and penile swab. Their female counterparts underwent swabs of the uterine cervix and oral mucosa. HPV-DNA detection was performed by polymerase chain reaction and restriction fragment length polymorphism.

RESULTS

HPV-DNA was detected in the penis, vagina/cervix, and oral cavity of 16 couples (51.61%). Of these, HPV-DNA concordance was observed in 14 couples (87.5%). HPV-DNA was amplified in penile and oral sites of 14 couples. Of these, 13 couples reported fellatio (92.85%), most of them (10 couples, 76.9%) without condom use. HPV-DNA concordance was observed in 7/10 of these couples (70%). The three couples (100%) who reported use of condom during fellatio were HPV-DNA discordant (p = 0.025).

CONCLUSIONS

Lifetime number of female sexual partners and detection of HPV-DNA in the penile mucosa are surrogate markers of exposure to HPV during marriage. Consistent use of condoms may reduce the risk of HPV transmission.

CLINICAL RELEVANCE

Oral acquisition of HPV from oro-genital contact is influenced by lack of condom use and previous sexual behavior of the male partner. In addition, oral transmission of the virus due to fellatio is as common as genital transmission.

Oral and genital human herpesvirus 8 and human papillomavirus in heterosexual partners

BACKGROUND

The purpose of this study was to verify a possible co-infection of human herpesvirus 8 (HHV-8) in commonly associated human papillomavirus (HPV) penile lesions and to determine the frequency of detection of these viruses in the oral mucosa of their female counterparts.

METHODS

Thirty-one male subjects underwent penile swabs from clinical HPV-related lesions. Their female counterparts underwent swabs of the vagina, uterine cervix, and oral mucosa. HPV and HHV-8 detection was performed by polymerase chain reaction using the consensus primers MY11/MY09 and KS1/KS2, respectively.

RESULTS

HPV DNA was detected in 31/31 penile lesions. HPV DNA was also detected in 18/31 (58%) female genital brushings and 17/31 (54%) female oral brushings. HHV-8 DNA was detected in 1/31 (3.2%) male genital brushings and 3/31 (9.6%) female oral mucosa brushings. None of the female genital brushings were HHV-8 DNA-infected.

CONCLUSIONS

Based upon the results of this study, co-infection between HPV and HHV-8 in malignant and pre-malignant penile lesions is an unlikely finding.

Single-tube seminested PCR assay for detecting human papillomavirus in clinical samples

There is a growing appreciation of the potential value for routine screening for the presence of HPV not only for cervical specimens but also from oral cavity. The purpose of this study was to develop and clinically evaluate a single-tube seminested PCR assay for the detection of HPV. Several parameters such as PCR primers, primer annealing temperature, the number of PCR cycles and concentration of PCR components were optimized. The assay was evaluated using HPV inserts of type 6, 11, 16, 18, 31, 33, 38 and 51. Evaluation of seminested PCR assay was performed with cervical scrapings from 30 patients and buccal swabs from 30 head and neck cancer patients and results were compared with those of two-tube nested PCR. The results were found to be comparable with a total of 60% (36/60) of samples being positive for HPV using the single-tube assay, while 62% (37/60) positivity was found with two-tube PCR assay. We succeeded in developing a single-tube seminested PCR method for HPV DNA detection which is easier than the conventional nested PCR and can be further evaluated as a potential screening tool for detecting HPV in oral and cervical regions.

The integration of HPV-18 DNA in cervical carcinoma

AIMS

Little information is available on the patterns of integration into the host chromosomal DNA of cervical carcinomas of human papillomavirus type 18 (HPV-18) DNA, which is associated with up to 20% of these carcinomas. Because integration of the viral genome may be extremely important in the pathogenesis of cervical carcinoma, the aim of this study was to investigate which regions of HPV-18 DNA are integrated into the cellular DNA of cervical carcinomas.

METHODS

Southern analysis using four subgenomic probes covering the entire HPV-18 genome was used to map viral DNA integrated within cellular DNA. The polymerase chain reaction (PCR) was used to confirm the presence of specific regions of the viral genome.

RESULTS

In all 11 carcinomas there was a single major HPV-18 DNA integrant, retaining approximately 4000 bp of HPV-18 DNA, indicating that approximately half of the virus genome had been lost upon integration. Southern analysis suggested strongly that the viral breakpoint was within the E1/E2 gene boundary, with concomitant loss of part or all of the E2 ORF (open reading frame), all of the E4, E5, and L2 ORFs and part of the L1 ORF. These data were supported by the PCR results, which confirmed that the region of integrated HPV-18 DNA from nucleotides 6558 to 162 was present in all the carcinoma samples studied. Assuming that no genomic rearrangements, deletions, or insertions had occurred, 4131 bp of integrated HPV-18 DNA could be accounted for in eight cervical carcinoma samples. The results of Southern analysis also suggested that integration of HPV-18 DNA may have occurred at a specific host chromosomal site.

CONCLUSIONS

Broadly, the viral sequences retained upon HPV-18 integration resemble those found when HPV-16 is integrated. However, it appears that the HPV-18 E2 region is more consistently deleted.