Bovine papillomavirus type 4 L1 gene transfection in a Drosophila S2 cell expression system: absence of L1 protein expression.

The development of a bovine papillomavirus (BPV) vaccine is an outstanding challenge. BPV protein L1 gene transfection in the Drosophila melanogaster S2 cell expression system failed to produce L1 protein notwithstanding correct L1 gene insertion. Severe genetic inbalance in the host cell line, including cytogenetic alterations, may account for the lack of protein expression.

The human papillomavirus (HPV)-related cancer biology: An overview.

Despite the novel diagnostic methods and therapies implemented in oncology, the number of patients that succumb by the cancer remains high globally. Currently studies point out that 20-25% of all human malignancies are related to micro-organism infections. Among these cancer-related pathogens, the human papillomavirus (HPV) has a prominent position, since the virus is responsible for about 30% of all infectious agent-related cancers. Thus, an amount of cancers could be avoided by means prophylactic and/or therapeutic measures. However, these measures required a holistic comprehension about HPV-related cancer biology. Based on this, this review aims to summarize the last evidences of HPV on cancer biology (from initiation to metastasis), focus on molecular and biochemical deregulations associated with viral infection, and discuss the viral etiology in different malignancies.

Integrated analysis of recombinant BPV-1 L1 protein for the production of a bovine papillomavirus VLP vaccine.

Bovine papillomatosis is an infectious disease that is caused by bovine papillomavirus (BPV), which results in important economic losses. However, no BPV vaccines or effective treatment methods are commercially available to date. Moreover, the absence of papillomavirus replication in vitro makes the use of recombinant protein a promising candidate for vaccine formulations. Hence, we developed an integrated study on the L1 capsid protein of BPV-1, obtained from a bacterial expression system, regarding its purification, biosafety, thermostability and immunogenicity. The results indicated an absence of genotoxicity of the purified recombinant L1 protein, ß-sheet prevalence of secondary structure folding, protein stability under high temperatures as well as the presence of capsomeres and VLPs. In addition, preliminary experimental vaccination of calves showed the production of specific antibodies against BPV-1 L1.

Genetics and metabolic deregulation following cancer initiation: A world to explore.

Cancer is a group of highly complex and heterogeneous diseases with several causes. According to the stochastic model, cancer initiates from mutation in somatic cells, leading to genomic instability and cell transformation. This canonical pathway of carcinogenesis is related to the discovery of important mechanisms that regulate cancer initiation. However, there are few studies describing genetic and metabolic alterations that deregulate transformed cells, resulting in epithelial-mesenchymal transition (EMT) and its most dramatic consequence, the metastasis. This review summarizes the main genetics and metabolic changes induced by reactive oxygen species (ROS) that lead to EMT.

Using the comet and micronucleus assays for genotoxicity studies: A review.

Physical, chemical and biological agents can act in the DNA, resulting in mutation involved in cancer. Thus, genotoxic tests are required by regulatory agencies in order to evaluate potential risk of cancer. Among these tests, the comet assay (CA) and micronucleus assay (MNA) are the most commonly used. However, there are different protocols and recommendations already published. This is the first review, after the inclusion of CA in S2R1 guidance and OECD 489, which summarizes the main technical recommendations of both CA and MNA.

Morphometric evaluation and nonclassical criteria for the diagnosis of HPV infection and cytological atypia in cervical samples.

Herein, we evaluated cervical samples from normal tissue or HPV-infected tissue, to determine if the relative nuclear/cytoplasmic ratio (NA/CA) and the presence of nonclassical cytological criteria are a novel cytological criterion for the diagnosis of HPV. Significantly, larger NA/CA ratios were found for the HPV-ATYPIA+ and HPV+ATYPIA+ groups compared with HPV-ATYPIA- group, regardless of collection method. For the samples collected with a spatula, only three samples from the HPV-ATIPIA- group showed four or more nonclassical parameters (i.e., were positive), while a larger number of the samples in the HPV-ATYPIA+, HPV+ATYPIA-, and HPV+ATYPIA+ groups were positive (13, 4, and 13 samples, respectively). Among those collected with a brush, no sample showed four or more nonclassical criteria in the HPV-ATYPIA- group, while a number of samples were positive in the HPV-ATYPIA+, HPV+ATYPIA-, and HPV+ATYPIA+ groups (4, 3, and 4 samples, respectively). HPV infection was associated with significant morphometrical changes; no increase in the NA/CA ratio was found in the HPV+ATYPIA- samples, compared with the HPV-ATIPIA- samples collected with either a spatula or a brush. In conclusion, by including nonclassical cytological criteria into the patient diagnosis, we were able to reduce the number of false negative and false positive HPV diagnoses made using conventional cytology alone.