Expression profile of the PI3K-AKT-mTOR pathway in head and neck squamous cell carcinoma: Data from Brazilian population.

OBJECTIVE: The phosphatidylinositol 3-kinase/protein kinase-B/mammalian target of the rapamycin (PI3K-AKT-mTOR) signaling pathway is an important regulator of cell proliferation, survival, and motility. The gain or loss of function of proteins related to this pathway results in the neoplastic transformation in several types of cancers. This study aimed to evaluate the expression profile of the PI3K-AKT-mTOR pathway in patients with head and neck squamous cell carcinoma (HNSCC) and HNSCC cell lines. STUDY DESIGN: The study involved 26 formalin-fixed paraffin-embedded tissue samples from patients with HNSCC. The analysis of immunohistochemical expression of PI3K, AKT, p-mTOR, and phosphatase and tensin homolog (PTEN) proteins was performed by a quantitative assessment. The in vitro gene and protein expression evaluation was performed by real-time polymerase chain reaction and Western blot assay, respectively, in the human cell lines SCC-9 and FaDu. RESULTS: High levels of PI3K, AKT, and p-mTOR were found in most HNSCC tumors. Following this result, we observed low amounts or absence of PTEN in most samples. Additionally, the FaDu cells (pharynx) showed higher AKT expression but lower expression of p-mTOR compared with SCC-9 cells (oral cavity), which hints at a loco-anatomical relevance. CONCLUSION: Overall, this study found increased expression of the PI3K-AKT-mTOR pathway along with evident PTEN reduction in head and neck cancer.

Expression of CD90 and P75NTR stem cell markers in ameloblastomas: a possible role in their biological behavior.

Multicystic and unicystic ameloblastomas are benign odontogenic tumors that present distinct biological behavior. The investigation of stem cells has become an important branch of tumor biology, with several studies addressing the possible role of these cells in tumor growth, angiogenesis, progression, infiltration and invasiveness. This study evaluated the immunohistochemical expression of CD90(Thy-1) and P75NTR stem cell markers in multicystic and unicystic ameloblastomas. Seventeen (17) samples of ameloblastomas (multicystic, n = 10; unicystic, n = 7) were submitted to immunohistochemical reactions and graded semi-quantitatively. The Kolmogorov-Smirnov test was used to verify possible differences in CD90 and P75NTR expressions between multicystic and unicystic ameloblastomas (p < 0.05). CD90 immunostaining was observed in all multicystic ameloblastoma specimens (n = 10), in the cytoplasm of the fibroblasts and vascular endothelial cells of the tumor stroma, near the neoplastic odontogenic epithelia. The staining of stromal CD90 was significantly higher in multicystic than in unicystic ameloblastomas (p = 0.003). Nuclear P75NTR immunostaining was observed in all ameloblastoma specimens. A significant difference was seen in the epithelial staining of P75NTR between multicystic and unicystic types (p = 0.007). The increased expression of CD90 and P75NTR found in multicystic ameloblastomas suggests a behavioral biological difference between multicystic and unicystic ameloblastomas, as well as a difference in ameloblastoma development.

mTOR pathway protein immunoexpression as a prognostic factor for survival in head and neck cancer patients: a systematic review and meta-analysis.

BACKGROUND: Several mTOR pathway proteins are involved in the regulation of cellular anabolism, growth, proliferation, and survival. Activated proteins in the mTOR pathway are deregulated in multiple types of cancers and could influence prognosis. However, it is unclear whether deregulation of mTOR pathway proteins serves a prognostic role in patients with head and neck cancer (HNC). Furthermore, proteins in the mTOR pathway may be important targets for anticancer therapy. The aim of this study was to summarize existing cohort studies to determine whether immunoexpression of mTOR pathway proteins are important prognostic factors for survival in patients with HNC. MATERIALS AND METHODS: A systematic review was performed using the Cochrane, Lilacs, PubMed, ScienceDirect, Scopus, and Web of Science databases (up to 23 January 2015). A meta-analysis was conducted to measure the frequency of protein expression in head and neck cancer patient samples and the prognostic value of mTOR pathway proteins for overall survival (OS) and disease-free survival (DFS). RESULTS: Twelve studies were included in our final analysis. The meta-analysis revealed that the frequency of overall expression of mTOR pathway proteins was 74.42% (CI: 63.3 to 84.0, P < 0.001, n = 2016 samples). The survival meta-analysis showed a pooled hazard ratio for OS and DFS of 1.44 (95% confidence interval [95% CI] 1.14-1.73) and 1.18 (95% CI 0.71-1.64), respectively. CONCLUSION: This systematic review and meta-analysis support evidence that mTOR pathway proteins can be used as predictive markers for survival in patients with HNC because their expression was significantly associated with poor OS and short DFS.

Expression of CD90 and P75NTR stem cell markers in ameloblastomas: a possible role in their biological behavior

Abstract Multicystic and unicystic ameloblastomas are benign odontogenic tumors that present distinct biological behavior. The investigation of stem cells has become an important branch of tumor biology, with several studies addressing the possible role of these cells in tumor growth, angiogenesis, progression, infiltration and invasiveness. This study evaluated the immunohistochemical expression of CD90(Thy-1) and P75NTR stem cell markers in multicystic and unicystic ameloblastomas. Seventeen (17) samples of ameloblastomas (multicystic, n = 10; unicystic, n = 7) were submitted to immunohistochemical reactions and graded semi-quantitatively. The Kolmogorov-Smirnov test was used to verify possible differences in CD90 and P75NTR expressions between multicystic and unicystic ameloblastomas (p < 0.05). CD90 immunostaining was observed in all multicystic ameloblastoma specimens (n = 10), in the cytoplasm of the fibroblasts and vascular endothelial cells of the tumor stroma, near the neoplastic odontogenic epithelia. The staining of stromal CD90 was significantly higher in multicystic than in unicystic ameloblastomas (p = 0.003). Nuclear P75NTR immunostaining was observed in all ameloblastoma specimens. A significant difference was seen in the epithelial staining of P75NTR between multicystic and unicystic types (p = 0.007). The increased expression of CD90 and P75NTR found in multicystic ameloblastomas suggests a behavioral biological difference between multicystic and unicystic ameloblastomas, as well as a difference in ameloblastoma development.

Low rate of oropharyngeal human papillomavirus infection of women with cervical lesions and their partners: new data from Brazilian population.

BACKGROUND: Although the natural history of cervical and oral infection by human papillomavirus (HPV) has been intensely investigated, the ability of this virus to infect oral and genital mucosae in the same individual and its potential of communicability are still unclear. OBJECTIVES: This study aimed at assessing the presence of oropharyngeal HPV infection in women with cervical lesions and in their current sexual partners in a Brazilian population. METHODS: It included a total of 65 patients, 43 women and 22 male partners. Medical history and the sociobehavioral profile were assessed through interviews that included the association of oropharyngeal HPV and the sexual behavior of patients, and also extra and intra-oral examinations were performed. Brushing was used to collect cells from the oropharyngeal mucosa. HPV DNA was checked through nested PCR with primers PGMY09/11 and GP5+/6+, and Pappilocheck to genotyping. RESULTS: Oropharyngeal HPV infection was detected in four of 65 (6.15%) cases, with one of 43 (2.3%) women, and three of 22 (13.6%) male partners. Clinically no patient showed HPV-related oral lesions. Pappilocheck assay showed the absence of HPV genotype commonly found in cervical mucosa. Moreover, there was no correlation between the presence of oropharyngeal HPV and sexual behavior risk factors. CONCLUSIONS: The results suggest that the presence of cervical lesions does not lead to HPV oropharyngeal infection. It also highlights the low rate of HPV infection in the oropharyngeal mucosa of women with cervical lesions and their partners in a researched sample.

Evaluation of immunohistochemical expression of p16 and presence of human papillomavirus in oral and oropharyngeal carcinoma.

Carcinogenesis concerns several changes that eventually result in the inactivation of tumor suppressor genes and activation of protooncogenes, leading to loss of cell cycle control. Inactivation of p16 seems to be an early event in this process and occurs in approximately 80% of squamous cell carcinoma cases. The aims of this study were to evaluate the immunohistochemical expression of p16 protein in oral and oropharyngeal squamous cell carcinoma cases, with both the tumoral area itself and its surgical margin being analyzed (dysplastic areas and histologically normal epithelium adjacent to carcinoma), and to verify the presence of human papillomavirus (HPV) and its relation to p16 expression. Paraffin-embedded biopsy tissues from 26 patients, 13 with oral squamous cell carcinoma and 13 with oropharyngeal squamous cell carcinoma, comprised the analyzed samples. To detect HPV, a nested polymerase chain reaction test using PGMY 09/11 and GP5*/GP6* primers and visualization of the product on a 2% agarose gel was performed. Demographic data were obtained from medical records. The results showed low expression of p16 in the tumor area (38.46%), compared with surgical margins in the histologically normal epithelium (84.6%) and dysplastic areas (57.7%). These findings indicate the inactivation of p16 in the process of malignant transformation. The association described in the literature between expression of p16 and presence of HPV could not be verified in this study, because none of the cases was HPV positive.

Assessing oral brushing technique as a source to collect DNA and its use in detecting human papillomavirus.

Collecting buccal cell DNA has a number of advantages in terms of practicality and technical quality when employed for detecting human papillomavirus (HPV), arguably an important etiological factor for head and neck carcinomas. The objective of the present study was to assess oropharyngeal mucosa brushing as an effective method for collecting DNA samples and for detecting HPV. Forty-three female patients diagnosed with cervical intraepithelial neoplasia, and 21 of their spouses, both groups without clinically detectable oral lesions, were submitted to quantitative and qualitative DNA analysis obtained through buccal cell brushing, with spectrophotometry assessment and beta-globin PCR. DNA samples were also checked for the presence of HPV. Efficient collection of DNA was achieved in all the sample cases. Two samples, a male and a female (not sexual partners), showed HPV-positivity. The results revealed that the oral brushing technique is an effective method for DNA collection to detect HPV, confirming that it could usefully contribute to epidemiological studies undertaken in Brazil's Public Health System. HPV detection using PCR showed that only 3.12% of the cases were HPV-positive. Although the sample was small, our study nevertheless allowed the detection of HPV in DNA samples of oral biological material.