Control of HPV replication: implications for squamous neoplasia

Molecular events in uterine cervical cancer

OBJECTIVE

To review the literature regarding the molecular events which occur in the development of uterine cervical cancer, with particular reference to human papillomavirus (HPV) infection.

METHODOLOGY

Bibliographic searches of Medline and the ISI citation databases using appropriate keywords, including the following: papillomavirus, cervix, pathology, cyclin, chromosome, heterozygosity, telomerase, smoking, hormones, HLA, immune response, HIV, HSV, EBV.

CONCLUSIONS

It has become clear that most cervical neoplasia, whether intraepithelial or invasive, is attributable in part to HPV infection. However, HPV infection alone is not sufficient, and, in a small proportion of cases, may not be necessary for malignant transformation. There is increasing evidence that HPV gene products interfere with cell cycle control leading to secondary accumulation of small and large scale genetic abnormalities. This may explain the association of viral persistence with lesion progression but, in many patients, secondary factors, such as smoking and immune response, are clearly important. However, the mechanisms involved in the interaction between HPV and host factors are poorly understood.

expression patterns of cyclins D1 and E in condyloma acuminatum in comparison with psoriatic proliferative lesions

Human papillomavirus (HPV) is able to subvert the host cell replication machinery so as to foster viral reproduction. Specifically, HPV infection is known to induce expression of proliferation antigens such as Ki67 and proliferative cell nuclear antigen (PCNA) in differentiated keratinocytes which have ceased to replicate. In order to determine whether cyclin D1 or cyclin E deregulation is also a feature of HPV infection, an immunohistochemical investigation of cyclin D1, cyclin E, Ki67, and PCNA expression has been carried out in 38 cases of HPV 6/11-related condyloma acuminatum (CA). Results were compared with those obtained from 15 psoriatic proliferative lesions. Whereas 35 (92.1 per cent) CA samples exhibited positive nuclear immunostaining for cyclin E, no cyclin D1 immunoreaction was detected in any of the CA samples studied. All psoriatic lesions showed immunostaining for both cyclins. All CA cases revealed a positive immunoreaction for Ki67 and 33 for PCNA, both in the parabasal and in the differentiated upper epithelial layers. Parabasal keratinocytes of psoriatic lesions were always positive for both Ki67 and PCNA. These results indicate that in the onslaught of HPV 6/11 upon the keratinocyte replication machinery, cyclin E, PCNA, and Ki67 are amongst the targeted cell cycle modulators, whereas cyclin D1 is spared the main effects of virus-cell interplay. In contrast, both cyclins seem to be induced in psoriasis, a non-viral proliferative skin condition.

Genital human papillomavirus infections: knowledge, perception of risk, and actual risk in a nonclinic population of young women

The purpose of this study was to assess knowledge, beliefs, and attitudes about genital human papillomavirus (HPV) infections in a group of young women in a nonclinic setting and to examine the association between perception of risk and actual risk. One hundred ten women attending a state university participated in the study and were asked to complete a self-administered questionnaire about knowledge and perceptions of risk. They were then offered testing for the virus using a self-administered vaginal method. The mean age was 20 +/- 1.2 years. Ninety (82%) were sexually experienced (SE), with a mean number of lifetime partners of 5.1 +/- 4.3. The mean knowledge score was less than the 68th percentile, reflecting low levels of knowledge about genital HPV infections. The SE group had a higher knowledge score than the sexually inexperienced (p < .02), but there were no differences in knowledge between those who chose to be tested and those who refused testing. The majority of women attributed negative emotion to being hypothetically tested positive for HPV. Emotions selected by > 50% of the group included feeling scared, angry, guilty, anxious, confused, dirty, regretful, and panicky. A greater negative emotion score was associated with refusing HPV testing (p < .002). Of the SE women, 58% (51) perceived themselves at risk, and, of this group, 71% (36) agreed to be tested. Of the women who agreed to HPV testing, 36% who perceived themselves at risk and 35% who did not perceive themselves at risk were, in fact, positive for HPV (p = ns). The majority of women have little knowledge of HPV infections and have attributed many negative emotions associated with infectivity. These negative attributes appear to influence women's decision making concerning HPV testing. The risk of HPV infection in this nonclinic group was substantial, suggesting that even in a nonclinic group, the prevalence of HPV is quite high. Perception of risk was unrelated to actual risk (HPV positive test), reflecting the lack of self-identified risk.