Effects of the juçara fruit (Euterpe edulis Martius) pulp and lyophilized extract on NRF2, KEAP1, SOD1, and GPX2 expression in human colorectal cancer cell lines

We investigated the effects of the juçara fruit (Euterpe edulis Martius) pulp and lyophilized extract on the expression of cytoprotective genes nuclear factor erythroid 2 (NF-E2)-related factor 2 (NRF2), kelch-like ECH-associated protein 1 (KEAP1), superoxide dismutase (SOD1), and glutathione peroxidase (GPX2) in human colorectal cancer cell lines (HT-29 and Caco-2). Cells were cultured for 24 h in Dulbecco's Modified Eagle's Medium containing juçara fruit pulp (5, 10, or 50 mg/mL) or lyophilized extract (0.05, 0.1, or 0.5 mg/mL), and gene expression was quantified using real-time quantitative reverse transcription polymerase chain reaction. All studied genes showed significant variation in gene expression among different concentrations of pulp or lyophilized extract. Overall, the expression of the selected genes decreased in both cell lines following exposure to the pulp or lyophilized extract in a dose-dependent manner for most of the concentrations studied. In summary, our study showed that the compounds in juçara fruit inhibited the expression of cytoprotective genes associated with the antioxidant response and that, although not cytotoxic at the concentrations studied, they could potentially block the activation of the NRF2/KEAP1 pathway.

Leptin receptor expression and Gln223Arg polymorphism as prognostic markers in oral and oropharyngeal cancer

The leptin gene product is released into the blood stream, passes through the blood-brain barrier, and finds the leptin receptor (LEPR) in the central nervous system. This hormone regulates food intake, hematopoiesis, inflammation, immunity, differentiation, and cell proliferation. The LEPR Gln223Arg polymorphism has been reported to alter receptor function and expression, both of which have been related with prognostics in several tumor types. Furthermore, several studies have shown a relationship between the Gln223Arg polymorphism and tumor development, and its role in oral and oropharyngeal squamous cell carcinoma is now well understood. In this study, 315 DNA samples were used for LEPR Gln223Arg genotyping and 87 primary oral and oropharyngeal squamous cell carcinomas were used for immunohistochemical expression analysis, such that a relationship between these and tumor development and prognosis could be established. Homozygous LEPR Arg223 was found to be associated with a 2-fold reduction in oral and oropharyngeal cancer risk. In contrast, the presence of the Arg223 allele in tumors was associated with worse disease-free and disease-specific survival. Low LEPR expression was found to be an independent risk factor, increasing the risk for lymph node metastasis 4-fold. In conclusion, the Gln223Arg polymorphism and LEPR expression might be valuable markers for oral and oropharyngeal cancer, suggesting that LEPR might serve as a potential target for future therapies.

FAS ligand expression in inflammatory infiltrate lymphoid cells as a prognostic marker in oral squamous cell carcinoma

Currently, the most important prognostic factor in oral squamous cell carcinoma (OSCC) is the presence of regional lymph node metastases, which correlates with a 50% reduction in life expectancy. We have previously observed that expression of hypoxia genes in the tumor inflammatory infiltrate is statistically related to prognosis in OSCC. FAS and FASL expression levels in OSCC have previously been related to patient survival. The present study analyzed the relationship between FASL expression in the inflammatory infiltrate lymphoid cells and clinical variables, tumor histology, and prognosis of OSCC. Strong FASL expression was significantly associated with lymph node metastases (P = 0.035) and disease-specific death (P = 0.014), but multivariate analysis did not confirm FASL expression as an independent death risk factor (OR = 2.78, 95%CI = 0.81-9.55). Disease-free and disease-specific survival were significantly correlated with FASL expression (P = 0.016 and P = 0.005, respectively). Multivariate analysis revealed that strong FASL expression is an independent marker for earlier disease relapse and disease-specific death, with approximately 2.5-fold increased risk compared with weak expression (HR = 2.24, 95%CI = 1.08-4.65 and HR = 2.49, 95%CI = 1.04-5.99, respectively). Our results suggest a potential role for this expression profile as a tumor prognostic marker in OSCC patients.

Genomics and proteomics approaches to the study of cancer-stroma interactions

Background

The development and progression of cancer depend on its genetic characteristics as well as on the interactions with its microenvironment. Understanding these interactions may contribute to diagnostic and prognostic evaluations and to the development of new cancer therapies. Aiming to investigate potential mechanisms by which the tumor microenvironment might contribute to a cancer phenotype, we evaluated soluble paracrine factors produced by stromal and neoplastic cells which may influence proliferation and gene and protein expression.

Methods

The study was carried out on the epithelial cancer cell line (Hep-2) and fibroblasts isolated from a primary oral cancer. We combined a conditioned-medium technique with subtraction hybridization approach, quantitative PCR and proteomics, in order to evaluate gene and protein expression influenced by soluble paracrine factors produced by stromal and neoplastic cells.

Results

We observed that conditioned medium from fibroblast cultures (FCM) inhibited proliferation and induced apoptosis in Hep-2 cells. In neoplastic cells, 41 genes and 5 proteins exhibited changes in expression levels in response to FCM and, in fibroblasts, 17 genes and 2 proteins showed down-regulation in response to conditioned medium from Hep-2 cells (HCM). Nine genes were selected and the expression results of 6 down-regulated genes (ARID4A, CALR, GNB2L1, RNF10, SQSTM1, USP9X) were validated by real time PCR.

Conclusions

A significant and common denominator in the results was the potential induction of signaling changes associated with immune or inflammatory response in the absence of a specific protein.

GAPD and tubulin are suitable internal controls for qPCR analysis of oral squamous cell carcinoma cell lines

The selection of housekeeping genes is critical for gene expression studies. To address this issue, four candidate housekeeping genes, including several commonly used ones, were investigated in oral squamous cell carcinoma cell lines. A simple quantitative RT-PCR approach was employed by comparing relative expression of the four candidate genes within two cancerous cell lines (HN6 and HN31) and one noncancerous cell line (HaCaT) treated or not with EGF and TGF-beta1. Data were analyzed using ANOVA followed by the NormFinder software program. On this basis, stability of the candidate housekeeping genes was ranked and non statistical differences were found using ANOVA test. On the other hand, the NormFinder was able to show that GAPD and TUBB presented the less variable results, representing appropriated housekeeping genes for the samples and conditions analyzed. In conclusion, this study suggests that the GAPD and the TUBB represent adequate normalizers for gene profiling studies in OSCC cell lines, covering, respectively, high and low expression levels genes.

EBV detection in HIV-related oral plasmablastic lymphoma

OBJECTIVES

Plasmablastic lymphoma (PBL) of the oral cavity is an aggressive neoplasm derived from B cell, considered to be the second more common among human immunodeficiency virus (HIV)-associated malignancies. As Epstein-Barr virus (EBV) infection has been associated with this neoplasm, the aim of the present study was to assess the presence of EBV in 11 cases of oral HIV-related PBL and investigate the controversial issue of the presence of Human herpesvirus-8 (HHV-8) in these tumors.

METHODS

DNA was extracted from nine cases of HIV-associated oral lymphomas, diagnosed as PBL, and genomic material was amplified by polymerase chain reaction to verify the presence of EBV. In situ hybridization (ISH) for EBV was performed in five cases. Immunohistochemical analysis was conducted to confirm previous diagnosis and verify HHV-8 infection.

RESULTS

The 11 cases had diagnosis confirmed by immunohistochemical analysis. Only nine cases presented an adequate amount of DNA for analysis, and EBV was detected in seven of them. The five cases tested for EBV viral infection by ISH showed positive signals. All 11 cases were negative for HHV-8.

CONCLUSION

The presence of EBV in all cases studied favors a direct role of this virus in the development of HIV-related PBL, and this finding could be considered when dealing with HIV patients.

The homeobox HOXB13 is expressed in human minor salivary gland

BACKGROUND

Homeobox are a family of developmental genes involved in morphogenesis and cellular differentiation. Participation of homeobox within normal and malignant tissue has been recently discussed in the literature.

OBJECTIVE

To analyze the presence of HOXB13 transcript expression in human minor salivary gland.

MATERIAL AND METHODS

Ten-micrometer sections from frozen samples were evaluated employing non-radioactive in situ hybridization technique and HOXB13 mRNA probes.

RESULTS

HOXB13 was found to be expressed in ducts and mucous acini but not in serous acini.

CONCLUSIONS

RESULTS suggest that HOXB13 transcripts are differently expressed in normal mucous and serous acini, and it may possibly reflect a different role in salivary gland carcinogenesis.

Osteolipoma: a rare lesion in the oral cavity

We present the case of a 65-year-old woman who had a painless mass in the left buccal mucosa. Histology showed a benign osteolipoma.

Immunohistochemical expression of retinoblastoma pathway proteins in normal salivary glands and in salivary gland tumours

The expression of G1-phase cell-cycle regulators is commonly deregulated in human malignancies. In the present study, we investigate components of the retinoblastoma (RB) pathway in normal salivary glands (NSG) and in salivary gland tumours (SGT). Samples of NSG, pleomorphic adenoma (PA), adenoid cystic carcinoma (ACC), mucoepidermoid carcinoma (MEC), epithelial-myoepithelial carcinoma (EMC), malignant myoepithelioma (MEM), carcinoma ex pleomorphic adenoma (CEPA), and polymorphous, low-grade adenocarcinoma (PLGA) were examined immunohistochemically using antibodies to cyclin D1, cyclin-dependent kinase 4 (CDK-4), retinoblastoma protein (pRb), CDK inhibitor p16 and transcription factor E2F-1. In normal salivary glands, cyclin D1 and cdk-4 were not expressed in any case while p16 was positively expressed. pRb was abundant and E2F-1 moderately expressed. In tumors, cdk-4 was overexpressed in half of the cases. Most tumour cases showed decreased pRb immunoexpression compared to normal salivary glands. In contrast, expression of p16 and E2F-1 increased. pRb expression was absent in three cases of PA, two of EMC and one of CEPA. One case of MEM and one of PLGA showed no E2F-1 expression. Statistical analyses revealed positive correlations between cyclin D1 and cdk-4, cyclin D1 and E2F-1, cdk-4 and E2F-1, and p16 and E2F-1. The benign and malignant tumours expressed retinoblastoma pathway proteins differently form the normal salivary gland. Our findings suggest that, pRb pathway deregulation in salivary gland neoplasms is unrelated to their biological behaviour.

Moebius syndrome with oral involvement

The oral findings of 12 patients with Moebius syndrome are described. Facial weakness, hypoplastic upper lip, microstomia, mouth-angle drooping, hypoplasia of mandible, gothic palate, tongue weakness, fissured tongue, tongue atrophy and open bite were found. In addition to describing the oral findings, this report discusses some implications for dental treatment of patients with this syndrome.

Population studies of the Y-chromosome of loci DYS390, DYS391 and DYS393 in Brazilian subjects and its use in human identification

Human identification can be accomplished by several technical procedures, especially by the comparative analysis of dental documents. Recent advances in molecular biology have now widened the scope for human identification and defined the protocols for the collection of biological material. Allele patterns of a population are particularly useful and they should be verified since they vary in different populations. We have studied the frequency of the alleles in three STR loci of the Y chromosome (DYS390, DYS391 and DYS393) in a group of Brazilian caucasian subjects. Results presented alleles 21, 22, 23, 24, 25 and 26 in locus DYS390, alleles 8, 9, 10, 11 12 and 13 in STR DYS391 and alleles in STR DYS393 were 11, 12, 13 14 and 15. The highest frequencies were 24 (0.46), 11 (0.37) and 13 (0.45). Each of the three STR systems had a PE (power of exclusion) of 0.6764 (DYS390), 0.5988 (DYS391) and 0.6136 (DYS393), The combination of the three STR systems revealed a PE of 0.9498, suggesting that this data can help in human identification.

Well-differentiated liposarcoma of the tongue

Intraoral liposarcomas are rare, with most reported cases being of the myxoid histological type. We present a well-differentiated liposarcoma of the tongue, in a 65-year-old man. The tumour presented lipoblasts in various stages of differentiation, lipocytes in different sizes and shapes, mesenchymal and signet-ring cells. Lipoma, spindle-cell lipoma, myxoma, hibernoma, angiolipoma, fibrolipoma, pseudosarcomatous faciitis and malignant hysticytoma were considered in the diagnosis process. The patient was treated surgically and so far is free of disease.

[Evaluation of 3 methods of DNA extraction from paraffin-embedded material for the amplification of genomic DNA using PCR]

There are several protocols reported in the literature for the extraction of genomic DNA from formalin-fixed paraffin-embedded samples. Genomic DNA is utilized in molecular analyses, including PCR. This study compares three different methods for the extraction of genomic DNA from formalin-fixed paraffin-embedded (inflammatory fibrous hyperplasia) and non-formalin-fixed (normal oral mucosa) samples: phenol with enzymatic digestion, and silica with and without enzymatic digestion. The amplification of DNA by means of the PCR technique was carried out with primers for the exon 7 of human keratin type 14. Amplicons were analyzed by means of electrophoresis in an 8% polyacrylamide gel with 5% glycerol, followed by silver-staining visualization. The phenol/enzymatic digestion and the silica/enzymatic digestion methods provided amplicons from both tissue samples. The method described is a potential aid in the establishment of the histopathologic diagnosis and in retrospective studies with archival paraffin-embedded samples.

Ectopic noggin blocks sensory and nonsensory organ morphogenesis in the chicken inner ear

Bone morphogenetic protein 4 (Bmp4) is expressed during multiple stages of development of the chicken inner ear. At the otocyst stage, Bmp4 is expressed in each presumptive sensory organ, as well as in the mesenchymal cells surrounding the region of the otocyst that is destined to form the semicircular canals. After the formation of the gross anatomy of the inner ear, Bmp4 expression persists in some sensory organs and restricted domains of the semicircular canals. To address the role of this gene in inner ear development, we blocked BMP4 function(s) by delivering one of its antagonists, Noggin, to the developing inner ear in ovo. Exogenous Noggin was delivered to the developing otocyst by using a replication-competent avian retrovirus encoding the Noggin cDNA (RCAS-N) or implanting beads coated with Noggin protein. Noggin treatment resulted in a variety of phenotypes involving both sensory and nonsensory components of the inner ear. Among the nonsensory structures, the semicircular canals were the most sensitive and the endolymphatic duct and sac most resistant to exogenous Noggin. Noggin affected the proliferation of the primordial canal outpouch, as well as the continual outgrowth of the canal after its formation. In addition, Noggin affected the structural patterning of the cristae, possibly via a decrease of Msx1 and p75NGFR expression. These results suggest that BMP4 and possibly other BMPs are required for multiple phases of inner ear development.

Axial specification for sensory organs versus non-sensory structures of the chicken inner ear

A mature inner ear is a complex labyrinth containing multiple sensory organs and nonsensory structures in a fixed configuration. Any perturbation in the structure of the labyrinth will undoubtedly lead to functional deficits. Therefore, it is important to understand molecularly how and when the position of each inner ear component is determined during development. To address this issue, each axis of the otocyst (embryonic day 2.5, E2.5, stage 16–17) was changed systematically at an age when axial information of the inner ear is predicted to be fixed based on gene expression patterns. Transplanted inner ears were analyzed at E4.5 for gene expression of BMP4 (bone morphogenetic protein), SOHo-1 (sensory organ homeobox-1), Otx1 (cognate of Drosophila orthodenticle gene), p75NGFR (nerve growth factor receptor) and Msx1 (muscle segment homeobox), or at E9 for their gross anatomy and sensory organ formation. Our results showed that axial specification in the chick inner ear occurs later than expected and patterning of sensory organs in the inner ear was first specified along the anterior/posterior (A/P) axis, followed by the dorsal/ventral (D/V) axis. Whereas the A/P axis of the sensory organs was fixed at the time of transplantation, the A/P axis for most non-sensory structures was not and was able to be re-specified according to the new axial information from the host. The D/V axis for the inner ear was not fixed at the time of transplantation. The asynchronous specification of the A/P and D/V axes of the chick inner ear suggests that sensory organ formation is a multi-step phenomenon, rather than a single inductive event.

Theoretical study of coaxial fibers

A mathematical solution of the wave equation for coaxial fibers having four different refractive-index profiles is presented. The transcendental equations are obtained under LP approximation and calculated for comparison of HE(mn)-mode-dispersion characteristics. Attention is paid to the HE(11) and HE(12) modes because of their importance for modeling directional couplers, and calculations are carried out to obtain dispersion dependence on dimensional parameters of the fibers. The field expressions also are given, and the spatial distributions of the HE(11) and HE(12) modal fields of all coaxial structures for different conditions of propagation are calculated.

Vimentin in oral squamous cell carcinoma

The relationship between the histological grading of malignancy and the expression of vimentin and cytokeratin was studied in 43 cases of oral squamous cell carcinoma. Immunohistochemical analysis was carried out with the avidin-biotin method using monoclonal antibody anti-vimentin, and the peroxidase anti-peroxidase method using the polyclonal antibody anti-cytokeratin. All cases were classified according to the histological malignancy grading system proposed by Anneroth. All of the carcinomas were found to express cytokeratin, while 60.4% expressed vimentin. Vimentin was particularly noted in all tumors scored to have highly malignant cells.

Single heterostructure lasers: a picosecond light pulse source

In this paper we suggest a new use for single heterostructure semiconductor lasers as a source of high power pulses of coherent light with halfwidths of the order of 10 psec, repetition rates up to hundreds of hertz and tunable photon energy output. Our suggestion is based on the behavior shown by single heterostructure lasers at the Q-switching regime of operation when they exhibit the properties mentioned above.