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.

ABSTRACT. The bovine papillomavirus (BPV) causes papillomas that regress spontaneously, but can also progress to malignancy. This study evaluated the role of BPV in oncogenesis. Twenty-four samples from uninfected calves and the papillomas of BPV infected cattle were subjected to molecular diagnosis, as well as histopathological and immunohistochemical analyses. The comet assay (CA) was used to evaluate the clastogenic potential of BPV. The results confirmed the presence of BPV-2, 3, 5, and 9 in infected samples. Histopathological analysis revealed acanthosis, koilocytosis, hypergranulosis, hyperkeratosis, and transformed fibroblasts. E7 and L1 BPV proteins were detected in the epithelium, as well as in the connective tissues, indicating productive infection at different sites. CA 12943 Genetics and histopathological aspects of BPV ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (4): 12942-12954 (2015) results showed that BPV-2, 5, and 9 exhibit the same level of clastogenicity. These findings support the oncogenic action of BPV in establishing a favorable microenvironment for oncogenesis.

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ABSTRACT. Bovine papillomavirus (BPV) is an oncogenic virus associated with benign and malignant lesions, which result in notable economic losses. Peripheral blood samples and cutaneous papillomas were obtained from four adult beef cattle. Viral molecular identification was performed using specific primers for BPV-1, -2 and -4 in blood diagnosis and FAP59/FAP64 for skin papillomas. Histopathologic examination was done as a complementary and differential diagnosis. The fragments were purified, sequenced, and compared using BLASTn. The blood diagnosis showed the presence of BPV-2 and the analysis of cutaneous papillomas showed the presence of BPV-4, a new First description of BPV-12 and putative type BAPV8 in Brazil putative virus type BAPV8, and BPV-12, revealing for the first time the presence of BPV-12 and the putative type BAPV8 in beef cattle in Brazil. The sequences were deposited in the GenBank. Histopathology revealed acanthosis, hyperkeratosis, and koilocytosis in all samples analyzed. The presence of BAPV8 and BPV-12 in Brazil emphasizes the ubiquitous dissemination of BPVs in the herds of Brazil.

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Metarhizium is an entomopathogenic fungus widely employed in the biological control of arthropods. Hemocytes present in the hemolymph of invertebrates are the cells involved in the immune response of arthropods. Despite this, knowledge about Rhipicephalus microplus hemocytes morphological aspects as well as their role in response to the fungal infection is scarce. The present study aimed to analyze the hemocytes of R. microplus females after Metarhizium robertsii infection, using light and electron microscopy approaches associated with the cytotoxicity evaluation. Five types of hemocytes (prohemocytes, spherulocytes, plasmatocytes, granulocytes, and oenocytoids) were described in the hemolymph of uninfected ticks, while only prohemocytes, granulocytes, and plasmatocytes were observed in fungus-infected tick females. Twenty-four hours after the fungal infection, only granulocytes and plasmatocytes were detected in the transmission electron microscopy analysis. Hemocytes from fungus-infected tick females showed several cytoplasmic vacuoles with different electron densities, and lipid droplets in close contact to low electron density vacuoles, as well as the formation of autophagosomes and subcellular material in different stages of degradation could also be observed. M. robertsii propagules were more toxic to tick hemocytes in the highest concentration tested (1.0 × 10 8 conidia mL −1 ). Interestingly, the lowest fungus concentration did not affect significantly the cell viability. Microanalysis showed that cells granules from fungus-infected and uninfected ticks had similar composition. This study addressed the first report of fungal cytotoxicity analyzing ultrastructural effects on hemocytes of R. microplus infected with entomopathogenic fungi. These results open new perspectives for the comprehension of ticks physiology and pathology, allowing the identification of new targets for the biological control.

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Bovine papillomavirus (BPV) is considered a useful model to study HPV oncogenic process. BPV interacts with the host chromatin, resulting in DNA damage, which is attributed to E5, E6, and E7 viral oncoproteins activity. However, the oncogenic mechanisms of BPV E6 oncoprotein per se remain unknown. This study aimed to evaluate the mutagenic potential of Bos taurus papillomavirus type 1 (BPV-1) E6 recombinant oncoprotein by the cytokinesis-block micronucleus assay (CBMNA) and comet assay (CA). Peripheral blood samples of five calves were collected. Samples were subjected to molecular diagnosis, which did not reveal presence of BPV sequences. Samples were treated with 1 μg/mL of BPV-1 E6 oncoprotein and 50 μg/mL of cyclophosphamide (positive control). Negative controls were not submitted to any treatment. The samples were submitted to the CBMNA and CA. The results showed that BPV E6 oncoprotein induces clastogenesis per se, which is indicative of genomic instability. These results allowed better understanding the mechanism of cancer promotion associated with the BPV E6 oncoprotein and revealed that this oncoprotein can induce carcinogenesis per se. E6 recombinant oncoprotein has been suggested as a possible vaccine candidate. Results pointed out that BPV E6 recombinant oncoprotein modifications are required to use it as vaccine.