Cutaneous viral infections associated with ultraviolet radiation exposure

Enhanced Spontaneous Skin Tumorigenesis and Aberrant Inflammatory Response to UVB Exposure in Immunosuppressed Human Papillomavirus Type 8‒Transgenic Mice

Human papillomaviruses (HPVs) from the beta genus are commensal viruses of the skin usually associated with asymptomatic infection in the general population. However, in individuals with specific genetic backgrounds, such as patients with epidermodysplasia verruciformis, or those with immune defects, such as organ transplant recipients, they are functionally involved in sunlight-induced skin cancer development, mainly keratinocyte carcinoma. Despite their well-established protumorigenic role, the cooperation between β-HPV infection, impaired host immunosurveillance, and UVB exposure has never been formally shown in animal models. In this study, by crossing skin-specific HPV8-transgenic mice with Rag2-deficient mice, we have generated a preclinical mouse model, named Rag2^‒/‒:K14-HPV8. These mice display an unhealthy skin phenotype and spontaneously develop papilloma-like lesions spreading to the entire skin much more rapidly compared with Rag2^+/+:K14-HPV8 mice. Exposure to low doses of UVB radiation is sufficient to trigger severe skin inflammation in Rag2^‒/‒:K14-HPV8 but not in Rag2^+/+:K14-HPV8 mice. Their inflamed skin very much resembled that observed in cutaneous field cancerization in organ transplant recipients, showing high levels of UVB-damaged cells, enhanced production of proinflammatory cytokines, and mast cell recruitment to the dermis. Overall, this immunocompromised HPV8-transgenic mouse model shows that the coexistence of immune defects, β-HPV, and UVB exposure promotes skin cancer development.

Cutaneous beta HPVs, sun exposure and risk of squamous and basal cell skin cancers in Australia

BACKGROUND

Sun exposure causes cutaneous squamous (SCC) and basal cell (BCC) carcinomas. Human papillomavirus (HPV) infection might cause SCC.

METHODS

We examined associations of beta and gamma HPV infection in skin-swab DNA and serum antibodies with skin cancer risk, and modification of the carcinogenic effects of sun exposure by them, in case-control studies of 385 SCC cases, 832 BCC cases and 1100 controls nested in an Australian prospective cohort study (enrolled 2006-2009).

RESULTS

Presence of beta-1 and beta-3 HPV DNA appeared to increase risks for SCC and BCC by 30%-40% (P adjusted <0.01). BCC was also associated with genus beta DNA, OR=1.48; 95%CI 1.10-2.00 (P adjusted <0.01). Associations were strengthened with each additional positive beta HPV DNA type: SCC (OR=1.07; 95%CI 1.02-1.12) and BCC (OR=1.06; 95%CI 1.03-1.10), P trend <0.01. Positivity to genus beta or gamma in serology, and genus gamma in DNA, was not associated with either cancer. There was little evidence that any beta HPV type was more strongly associated than others with either cancer. A weaker association of sun-exposure with SCC and BCC in the presence of beta-3 HPVs than in their absence suggests that beta-3 HPVs modify sun exposure's effect.

CONCLUSIONS

Our substantive findings are at the level of genus beta HPV. Like SCC, BCC risk may increase with increasing numbers of beta HPV types on skin.

IMPACT

The consistency in our findings that HPV infection may moderate the effects of sun exposure, the main environmental cause of SCC and BCC, merits further investigation.

Emerging Oncogenic Viruses in Head and Neck Cancers from Romanian Patients

(1) Background: Head and neck squamous cell carcinomas (HNSCCs) are some of the most frequent malignancies globally. Oncogenic viruses MCPyV, EBV and HPVs are recognized to be related to HNSCCs and skin cancers. There are no data from Romania regarding the involvement of herpes viruses and polyomaviruses in these types of cancer. We aim to evaluate the association of oncogenic viruses from Papillomaviridae, Herpesviridae, and Polyomaviridae families in HNSCCs and skin cancers. (2) Methods: A total of 26 fresh tumors (6/26 women) were tested for 67 viral agents using a multiplex PCR genotyping assay. (3) Results: A total of 23/26 (88.5%) samples were positive for one or more viruses. All the tested tumors were negative for any HPV (alpha or beta types). In total, we detected as positive samples: 16 (61.63%) EBV1, 12 (46.15%) HHV7, 8 (30.76%) MCV, 6 (23.07%) CMV and HHV6, 2 (7.69%) HHV8, 1 (3.8%) HPyV6 and EBV2. (4) Conclusions: We detected HPV-negative cases that are HPyV and HHV positive. In these fractions of HPV-negative HNSCCs cases, other oncogenic viruses may be involved, such as EBV1, MCV or CMV. Additional research is required for clarifying the natural history of these viruses in HNSCCs, as virus detection would have a decisive impact on diagnostic and decisional algorithms.

Association between Human Polyomaviruses and Keratinocyte Carcinomas: A Prospective Cohort Study

BACKGROUND

A positive association between Merkel cell polyomavirus (MCPyV) infection and cutaneous squamous cell carcinoma (cuSCC) has been observed in at least one previous case-control study. To evaluate this association in a prospective context, we investigated infections with human polyomaviruses (HPyV), including MCPyV, as predictors of keratinocyte carcinomas, including cuSCC and basal cell carcinoma (BCC), among a cohort of immunocompetent individuals enrolled in the Viruses in Skin Cancer (VIRUSCAN) Study.

METHODS

Associations between markers of baseline HPyV infection (serum antibodies and viral DNA in eyebrow hairs and skin swabs) and incident keratinocyte carcinomas were modeled using Cox proportional hazards regression. Proportions of baseline HPyV infections that were concordant with a subsequent tumor positive for the same HPyV type were assessed.

RESULTS

No significant associations were observed between baseline markers of MCPyV or other HPyV infections and cuSCC or BCC. Less than 4.5% of baseline MCPyV infections were also detected in subsequently developed keratinocyte carcinoma tumors.

CONCLUSIONS

HPyV infection was not a predictor of keratinocyte carcinoma risk in this prospective cohort.

IMPACT

Cancer-associated infections represent attractive targets for cancer prevention; however, HPyV infections have limited potential as novel targets for cuSCC prevention.

Cutaneous Human Papillomaviruses and the Risk of Keratinocyte Carcinomas

Cutaneous human papillomavirus (cuHPV) infections may be novel targets for skin cancer prevention and treatment, but critical information regarding the development of virus-positive skin cancers following cuHPV infection has been lacking. In this study, baseline cuHPV infection was measured by serology and viral DNA detection in eyebrow hairs (EBH) and forearm skin swabs (SSW) among 1,008 individuals undergoing routine skin cancer screening exams and followed for incidence of basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cuSCC). Baseline β-HPV detection, particularly in SSW, significantly predicted cuSCC (HR = 4.32; 95% confidence interval, 1.00-18.66), whereas serologic evidence of past β-HPV infection was not associated with cuSCC. Less than 5% of baseline β-HPV types detected in SSW were present in subsequent cuSCC tumors, and cuHPV detected in SSW with higher mean fluorescence intensity values were more likely to be present in cuSCC compared with those with lower levels (P < 0.001). β-HPV-positive cuSCC occurred more often in areas of highly sun-damaged skin than did β-HPV-negative cuSCC. Overall, no clear patterns were observed between baseline β-HPV detection and subsequent development of BCC, or between baseline γ-HPV detection and either cuSCC or BCC. Collectively, these results demonstrate that β-HPV detection in SSW is a significant predictor of cuSCC risk, although evidence suggests only a small subset of cuSCC is etiologically linked to β-HPV infection. SIGNIFICANCE: β-HPV positivity may be a useful biomarker for identifying individuals who could benefit from increased screening or novel cutaneous squamous cell carcinoma prevention strategies.

Cutaneous viral infections associated with ultraviolet radiation exposure

The complex interplay between ultraviolet radiation (UVR) and cutaneous viral infections in the context of cancer etiology is challenging to unravel, given the limited information on the independent association between UVR and cutaneous viral infections. Using multiple biomarkers of infection with 24 types of cutaneous human papillomavirus (HPV) and 4 types of polyomaviruses (HPyV), we investigated cross-sectional associations with recent UVR exposure, using skin pigmentation measured by spectrophotometer. Age- and sex-adjusted associations between UVR and viral seropositivity, viral DNA present in eyebrow hairs (EBH) and skin swabs (SSW) were estimated using logistic regression. Beta-HPV seropositivity was associated with viral DNA positivity in EBH (OR = 1.40, 95% CI = 1.05-1.88) and SSW (OR = 1.86, 95% CI = 1.25-2.74). Similar associations were observed for Merkel cell polyomavirus. Participants in the highest tertile of UVR exposure were more likely to be seropositive for beta-HPV (OR = 1.81, 95% CI = 1.16-2.38), and have beta-HPV DNA in EBH (OR = 1.57, 95% CI = 1.06-2.33) and SSW (OR = 2.22, 95% CI = 1.25-3.96), compared to participants with the lowest tertile of UVR exposure. UVR exposure was positively associated with three different markers of beta-HPV infection. Therefore, future studies of HPV associated KC development should address more directly the role of HPV and UVR exposure as potential co-carcinogens.