The detection of human papillomaviruses in cervical biopsies by immunohistochemistry and in situ hybridization

Detection of Human Papillomavirus in Cervical Gradings by Immunohistochemistry and Typing of HPV 16 and 18 in High-Grades by Polymerase Chain Reaction

BACKGROUND

Cervical cancer has a major impact on developing countries, where screening programs are not well established or effective.

AIM

This study aims to investigate Human papillomavirus (HPV) 6, 11 and 18 expression in cervical biopsies by immunohistochemistry, (IHC) followed by typing of high-risk HPV 16 and 18 in high-grades by polymerase chain reaction (PCR).

SETTINGS AND DESIGN

During the study period of six months, 30 biopsy samples were obtained from patients attending various gynecology clinics in and around Trichy District, Tamil Nadu, between January and June 2009.

MATERIALS AND METHODS

The ecto- and endoscopic biopsy specimens of the cervix were fixed in 10% buffered formalin; routine paraffin sections were taken for processing and stained with hematoxylin and eosin. The samples were graded as Normal cervicitis, Cervical intraepithelial neoplasia (CIN) I, II, III, and squamous cell carcinoma (SCC), for original diagnosis by pathologists. The extra sections were studied for the expression of HPV 6, 11 and 18 by immunohistochemistry and HPV DNA 16 and18 by PCR.

RESULTS

Out of thirty samples, 15 expressed positive and 15 negative for HPV marker. Twenty-seven cases of cervical gradings have been categorized into high grade CIN II/III, SCC (23) and low grade CIN I (4). The high grades were subjected to PCR for high-risk typing. The results revealed that 15 cases were positive for HPV genotype 16 and eight cases for HPV genotype 18. The prevalence of HPV infection was found to be higher in women aged between 50 and 59.

CONCLUSION

This study reveals a significant detection of HPV in the South Indian suspected individuals, by the use of advanced techniques such as IHC and PCR.

Parenteral and oral immunization with a plasmid DNA expressing the human papillomavirus 16-L1 gene induces systemic and mucosal antibodies and cytotoxic T lymphocyte responses

The association of human papillomavirus (HPV) infection and cervical cancer has been demonstrated. The development of a prophylactic vaccine to protect against primary HPV infection may therefore be an efficient means to reduce the incidence of this cancer worldwide. To assess the capacity of a plasmid DNA that expresses the L1 gene of HPV type 16 to induce a protective immune response, mice were immunized by parenteral and oral routes. Animals that received the DNA vaccine intramuscularly, subcutaneously and orally, developed systemic anti-L1 IgG antibodies. Antibodies developed in mice vaccinated subcutaneously were detectable twelve months post-immunization. Specific IgA antibodies were also found in vaginal washes from immunized mice. Both systemic and local antibodies proved effective in a surrogate neutralization assay. Splenic T cells extracted from experimental mice showed cytotoxic T lymphocytes (CTL) activity mediated by CD8 + cells. Mice were challenged with a syngeneic melanoma cell line, engineered to express the HPV16-L1 protein, tumours in vaccinated animals showed slower growth rate, correlated directly with a longer survival of mice. The results suggest that the L1-based DNA vaccine may be useful for the prevention of primary infections by HPV16.

Patterns of p21(waf1/cip1) expression in non-papillomatous nasal mucosa, endophytic sinonasal papillomas, and associated carcinomas

AIMS

To clarify p21(waf1/cip1) expression in sinonasal lesions.

METHODS

Archived surgical specimens from 38 patients were investigated by means of immunohistochemistry. p21(waf1/cip1) staining was evaluated in the different layers of the epithelium. In addition, human papillomavirus (HPV) infection and p53 protein overexpression were assessed and correlated with p21(waf1/cip1) expression.

RESULTS

p21(waf1/cip1) staining was negative in non-papillomatous nasal mucosa. HPV infection and p53 protein overexpression were not seen. Sixteen of 20 inverted papillomas showed p21(waf1/cip1) expression. HPV infection was found in 16 cases and p53 protein overexpression was present in 13 specimens. Expression of p21(waf1/cip1) was restricted to surface cells in five cases, but involved basal/parabasal cells in 11 specimens. Immunoreactivity for p21(waf1/cip1) in basal/parabasal cells colocalised with p53 protein overexpression. Enhanced expression rates for p21(waf1/cip1) were seen in transitional and squamous epithelium compared with columnar epithelium. p21(waf1/cip1) expression involved only surface cells in cylindrical cell papillomas. HPV infection and p53 protein overexpression were detected in all specimens. One of five squamous cell carcinomas showed p21(waf1/cip1) expression. HPV infection was seen in two cases, and all carcinomas showed p53 protein overexpression.

CONCLUSIONS

Expression of p21(waf1/cip1) is associated with terminal differentiation in surface cells in inverted papillomas and cylindrical cell papillomas, but not in non-papillomatous nasal mucosa. Overexpression of p53 protein colocalises with p21(waf1/cip1) expression in basal/parabasal cells in inverted papillomas but not in cylindrical cell papillomas. Expression of p21(waf1/cip1) in squamous cell carcinomas involves a subset of tumours with p53 protein overexpression.