[Human papilloma virus infection in basal cell carcinoma of the skin: a systematic review and meta-analysis study].

Human papillomaviruses (HPVs) are a large and ubiquitous group of viruses that some of them have been suggested as a co-factor in the development of non-melanoma skin cancers. The aim of this meta-analysis study was to evaluate HPVs' prevalence in basal cell carcinoma (BCC) of the skin and the risk of them in the BCC patients compared with the healthy controls. Five databases were searched from January 1980 to February 2017. A random-effects meta-analysis was done with the event rate (ER) for the prevalence of HPVs and odds ratio (OR) for estimation of the incidence of HPVs. Out of 1087 studies, 45 studies were included in the review. The pooled analysis demonstrated that the incidence of γ-HPV was effective in the BCC patients compared with the healthy controls [OR = 1.97; 95% CI: 1.52-2.55; p < 0.00001], but not for α-HPV, ß-HPV and epidermodysplasia verruciformis (EV)-HPV (p > 0.05). The pooled ER of incidence of ß1-HPV in the BCC patients was z3.3% and for ß2-HPV in BCC patients was 44.2%. In conclusion, this meta-analysis showed that probably the risk of γ-HPV was more on BCC patients and also the rate of γ-HPV was higher than α-, ß- and EV-HPVs in the BCC patients.

[RNA interference: biogenesis molecular mechanisms and its applications in cervical cancer]. / RNA de interferencia: biogénesis, mecanismos moleculares y sus aplicaciones en cáncer cervical.

RNAi (RNA interference) is a natural process by which eukaryotic cells silence gene expression through small interference RNAs (siRNA) which are complementary to messenger RNA (mRNA). In this process, the siRNA that are 21-25 nucleotides long and are known as microRNA (miRNA), either associate with the RNA-induced silencing complex (RISC), which targets and cleaves the complementary mRNAs by the endonucleolytic pathway, or repress the translation. It is also possible to silence exogenous gene expression during viral infections by using DNA templates to transcribe siRNA with properties that are identical to those of bioactive microRNA. Persistent human papillomavirus (HPV) infection is the main etiological agent during cervical cancer development and the HPV E6 and E7 oncogenes, which induce cellular transformation and immortalization, represent strategic targets to be silenced with siRNA. In several in vitro and in vivo studies, it has been demonstrated that the introduction of siRNA directed against the E6 and E7 oncogenes in human tumoral cervical cells transformed by HPV, leads to the efficient silencing of HPV E6 and E7 oncogene expression, which induces the accumulation of the products of the p53 and pRb tumor suppressor genes and activates the mechanism of programmed cell death by apoptosis; thus, the progression of the tumoral growth process may be prevented. The goal of this review is to analyze the microRNA biogenesis process in the silencing of gene expression and to discuss the different protocols for the use of siRNA as a potential gene therapy strategy for the treatment of cervical cancer.

Identification of a Novel Human Papillomavirus, Type HPV199, Isolated from a Nasopharynx and Anal Canal, and Complete Genomic Characterization of Papillomavirus Species Gamma-12.

The novel human papillomavirus type 199 (HPV199) was initially identified in a nasopharyngeal swab sample obtained from a 25 year-old immunocompetent male. The complete genome of HPV199 is 7,184 bp in length with a GC content of 36.5%. Comparative genomic characterization of HPV199 and its closest relatives showed the classical genomic organization of Gammapapillomaviruses (Gamma-PVs). HPV199 has seven major open reading frames (ORFs), encoding five early (E1, E2, E4, E6, and E7) and two late (L1 and L2) proteins, while lacking the E5 ORF. The long control region (LCR) of 513 bp is located between the L1 and E6 ORFs. Phylogenetic analysis additionally confirmed that HPV-199 clusters into the Gamma-PV genus, species Gamma-12, additionally containing HPV127, HV132, HPV148, HPV165, and three putative HPV types: KC5, CG2 and CG3. HPV199 is most closely related to HPV127 (nucleotide identity 77%). The complete viral genome sequence of additional HPV199 isolate was determined from anal canal swab sample. Two HPV199 complete viral sequences exhibit 99.4% nucleotide identity. To the best of our knowledge, this is the first member of Gamma-PV with complete nucleotide sequences determined from two independent clinical samples. To evaluate the tissue tropism of the novel HPV type, 916 clinical samples were tested using HPV199 type-specific real-time PCR: HPV199 was detected in 2/76 tissue samples of histologically confirmed common warts, 2/108 samples of eyebrow hair follicles, 2/137 anal canal swabs obtained from individuals with clinically evident anal pathology, 4/184 nasopharyngeal swabs and 3/411 cervical swabs obtained from women with normal cervical cytology. Although HPV199 was found in 1.4% of cutaneous and mucosal samples only, it exhibits dual tissue tropism. According to the results of our study and literature data, dual tropism of all Gamma-12 members is highly possible.

Influence of oral sex and oral cancer information on young adults' oral sexual-risk cognitions and likelihood of HPV vaccination.

Public health information and educational interventions regarding human papillomavirus (HPV) have focused on the link between vaginal sex and cervical cancer among women. Many people are unaware that HPV can be transmitted through oral sex or that HPV causes oral cancers. Given that HPV infections and unprotected oral sex are increasing, research on oral sex-related HPV risk is important. This study examined the effect of a brief informational intervention regarding HPV and oral sex on the sexual risk cognitions of young adults. College students (N = 238) read information on HPV, oral sex, and oral cancer or no information. Participants then completed measures of oral sex and HPV knowledge, oral sex willingness, HPV vaccination likelihood, and risk perceptions. Participants who read the information on HPV and oral sex and cancer (compared to those who did not) reported greater knowledge, perceived risk and concern, and lower willingness to engage in oral sex. These effects were only significant among women. However, men reported a higher likelihood of future HPV vaccination compared to women who had not yet received the vaccine. Focusing on oral sex and cancer, this study adds to research investigating ways to reduce HPV infections.

NF-κB signalling is attenuated by the E7 protein from cutaneous human papillomaviruses.

The high-risk Alpha-types of human papillomavirus (HPV) are the causative agent of cervical cancer, which is the second major cause of death among women worldwide. Recent investigations have shown that E7 from the Alpha-papillomavirus HPV-16 interacts with IKKα and IKKß of the IKK complex in the NF-κB pathway leading to an attenuation of the activity. There is a possible link between development of non-melanoma skin cancer and cutaneous Beta-papillomavirus but if these HPV types attenuate the NF-κB pathway is unclear. Seven different E7 proteins, representing four out of the five different species of the Beta genus (HPV-20, -37, -38, -92, -93 and -96) and one from the Gamma genus (HPV-4) were investigated for potential modulation of the NF-κB pathway in U2OS cells. Our results demonstrate that E7 from all the cutaneous HPV types were capable of inhibiting the NF-κB activity as well as E7 from HPV-16. In addition, E7 proteins from the cutaneous HPV types demonstrated interaction with IKKα but not with IKKß. The deregulation of the NF-κB pathway by cutaneous HPVs might contribute to the pathogenesis of non-melanoma skin cancers and its precursors.