Fernanda Salgueiredo Giudice

Low-level laser therapy can produce increased aggressiveness of dysplastic and oral cancer cell lines by modulation of Akt/mTOR signaling pathway

Low-level laser therapy (LLLT) is a non-thermal phototherapy used in several medical applications, including wound healing, reduction of pain and amelioration of oral mucositis. Nevertheless, the effects of LLLT upon cancer or dysplastic cells have been so far poorly studied. Head and neck cancer patients receiving LLLT for oral mucositis, for example, might have remaining tumor cells that could be stimulated by LLLT. This study demonstrated that LLLT (GaAlAs--660 nm or 780 nm, 40 mW, 2.05, 3.07 or 6.15 J/cm²) can modify oral dysplastic cells (DOK) and oral cancer cells (SCC9 and SCC25) growth by modulating the Akt/mTOR/CyclinD1 signaling pathway; LLLT significantly modified the expression of proteins related to progression and invasion in all the cell lines, and could aggravate oral cancer cellular behavior, increasing the expression of pAkt, pS6 and Cyclin D1 proteins and producing an aggressive Hsp90 isoform. Apoptosis was detected for SCC25 and was related to pAkt levels.

Different expression patterns of pAkt, NF-κB and cyclin D1 proteins during the invasion process of head and neck squamous cell carcinoma: an in vitro approach.

BACKGROUND Several signaling pathways are involved in the progression of squamous cell carcinoma. Among them, activated PI3K/Akt may result in NF-κB nuclear translocation, thus leading to the transcription of genes enrolled in cellular invasion and proliferation, such as cyclin D1. This study sought to evaluate the expression of pAkt, NF-κB and cyclin D1 proteins in head and neck squamous cell carcinoma cell lines and their respective in vitro-obtained invasive clones. METHODS Squamous cell carcinoma cell lines originating from the tongue, pharynx and the metastatic lymph node were submitted to an in vitro invasion assay to select invasive clones. All experimental groups were submitted to immunofluorescence and Western blot assays. Statistical analysis was performed through a Students t-test with a significance level of 5%. RESULTS The pAkt and NF-κB expression differed from cytoplasm and nucleus depending on the studied cell line. The invasive clone from the tongue presented a network-like structure of pAkts cytoplasmic expression. This lineage as well as the invasive clone from pharynx also showed pAkt and NF-κB nuclear transportation. Significant pAkt and NF-κB increases were observed in the tongue and pharynx invasive clones. Cyclin D1 was detected in the nucleus of all studied cells and was significantly enhanced in the invasive clones from tongue and pharynx. CONCLUSION This study suggests the participation of pAkt, NF-κB and cyclin D1 in the invasion process of head and neck squamous cell carcinoma. Moreover, cytoplasmic pAkt network-like structure was probably related to cytoskeleton changes presented during invasion.

Oestrogens and androgen receptors in oral squamous cell carcinoma

Abstract Objective. To investigate the gender-related expressions of androgen (AR), estrogen alpha (ERα) and beta (ERβ) receptors and aromatase enzyme in oral squamous cell carcinomas (OSCC). Materials and methods. A total of 60 cases of OSCC (30 from males and 30 from females) were retrieved and submitted to immunohistochemistry. Also, steroid expression was studied in two OSCC cell lines using Western blotting and immunofluorescence. Results. Immunohistochemistry demonstrated that ERβ was expressed in almost 40% of the cases and AR in 26%. Aromatase enzyme and ERα were less commonly expressed. Only AR presented statistically significant differences between genders. Western blotting and immunofluorescence analysis demonstrated that ERβ was abundantly expressed in the nuclei of both cell lines and aromatase enzyme presented a cytoplasmic expression. Conclusion. The detection of steroid hormones, especially ERβ, can indicate a role of these proteins in the process of carcinogenesis of some OSCC. Further studies of the mechanisms involved may provide important biological information regarding therapeutic approaches.

Oestrogen receptor β in adenoid cystic carcinoma of salivary glands.

Marques Y M F S, Giudice F S, Freitas V M, Abreu e Lima M d C C, Hunter K D, Speight P M & Machado de Sousa S C O 
(2012) Histopathology 60, 609–616
Oestrogen receptor β in adenoid cystic carcinoma of salivary glands

Myoepithelioma of the Soft Palate: a Case Report Giving Special Attention to the Differential Diagnosis

ABSTRACT Background Myoepitheliomas are rare tumours that may generally arise from the minor or major salivary glands. The differential diagnosis of this tumour should be performed along with several benign and malignant soft tissue neoplasms. The present case report describes an asymptomatic mass that arose in the soft palate of 42 year old black woman with duration of the six months. Methods An incisional biopsy of soft palate lesion was carried out and submitted for histological evaluation under the clinical hypothesis of salivary gland tumour. To confirm the myoepithelial nature of neoplastic cells the immunohistochemical reactions for smooth-muscle actin, cytokeratins and S100 were performed. Results The histological examination revealed the presence of tumour originating from a minor salivary gland and covered by a stratified squamous oral epithelium. The tumour cells were arranged in order to form a myxoid pattern and, individually, small and/or medium spindle-shaped cells with predominantly round or ovoid nuclei, as well as epithelioid and plasmocytoid cells were noted. The stroma was myxomatous and no ductal or syringomatous epithelial structures were observed. Following the histological and immunohistochemical diagnosis of myoepithelioma, the lesion was surgically removed. After the surgery, a follow-up of one year showed no signs and symptoms of reccurrence. Conclusions The myoepithelioma should be carefully distinguished from the other soft tissue tumours, especially those arising from salivary glands, such as pleomorphic adenoma and adenoid-cystic carcinoma.

Is it safe to utilize in vitro reconstituted human oral epithelium? An oncogenetic pathway study

Cell therapy is a therapeutic strategy used to replace or repair damaged tissue. The epithelium transplantation of cultivated keratinocytes has been applied to several modalities of reconstruction, like oral, urethra and ocular surface. Life and death signals work coordinately to ensure cellular quality control and the viability of an organism. The aim of this study is to verify that culture conditions did not induce genetic mutations through the analysis of the key genes: pAKT, Pten, p53 and MDM2 and investigate the presence of the related proteins in human oral keratinocytes obtained by primary culture and in vitro cultivated. Formalin fixed and paraffin embedded tissues from the oral cavity were utilized as control for normal expression of the related markers and two oral squamous cell carcinoma cell lines provided the expression pattern of the proposed markers in the event of cellular transformation. Akt, PTEN, p53 and MDM2 immunohistochemistry and Western-Blotting analyzes were performed. The results showed the expression levels and intracellular localizations of the four proteins evaluated. These analyzes confirmed that the produced in vitro epithelium is bio-compatible for its utilization as reconstruction and reparatory tissue, however further analyses and additional research on other biomarkers should be performed to analyse the long term engraftment of transplantable primary culture of oral keratinocytes and the long term resistance to cellular transformation.

Effects of celecoxib treatment over the AKT pathway in head and neck squamous cell carcinoma

BACKGROUND Celecoxib, a non-steroidal anti-inflammatory drug that selectively inhibits cyclooxygenase-2 (COX-2), has shown an important anticarcinogenic effect for the treatment of squamous cell carcinoma. The use of COX-2 inhibitors has effectively inhibited the growth of Head and Neck Squamous Cell Carcinoma (HNSCC) cell lines, while a recent phase 1 trial demonstrated good response rate of cancer cells to this drug with minimal toxicity. Possible targets of celecoxib include proteins involved in cell proliferation and apoptosis control. Additionally, celecoxib antitumoral activity has been linked with a COX-2-independent event. METHODS To better understand which cellular mechanisms are targeted by celecoxib, its effects upon the Akt signaling pathway using two different HNSCC cell lines were analyzed through cell viability assay, immunofluorescence, and Western blotting. RESULTS The results showed decreased levels of Cyclin D1 and pAkt protein expression in vitro. The number of viable cells was also diminished after celecoxib treatment. CONCLUSION As Akt pathway seems to be a valuable target for the HNSCC therapy, the results presented herein confirm that celecoxib can be considered as an alternative adjuvant drug for HNSCC treatment.

Vimentin expression and the influence of Matrigel in cell lines of head and neck squamous cell carcinoma.

Vimentin is a cytoeskeletal intermediate filament protein commonly observed in mesenchymal cells; however, it can also be found in malignant epithelial cells. It is demonstrated in several carcinomas, such as those of the cervix, breast and bladder, in which it is widely used as a marker of the epithelial to mesenchymal transition that takes place during embryogenesis and metastasis. Vimentin is associated with tumors that show a high degree of invasiveness, being detected in invasion front cells. Its expression seems to be influenced by the tumor microenvironment. The aim of this study was to evaluate vimentin expression in head and neck squamous cell carcinoma (HNSCC) cell lines, and to investigate the contribution of the microenvironment to its expression. HNSCC cell lines (HN6, HN30 and HN31) and an immortalized nontumorigenic cell line (HaCaT) were submitted to a three-dimensional assay with Matrigel. Cytoplasmatic staining of the HN6 cell line cultured without Matrigel and of the HN30 and HN31 cell lines cultured with Matrigel was demonstrated through immunohistochemistry. Western Blotting revealed a significant decrease in vimentin expression for the HN6 cell line and a significant increase for the HN30 and HN31 cell lines cultured with Matrigel. The results suggest that vimentin can be expressed in HNSCC cells and its presence is influenced by the microenvironment of a tumor.

Adenomatoid odontogenic tumour: A case report

Abstract Adenomatoid odontogenic tumour (AOT) is a rare benign odontogenic tumour characterized by a progressively slow growing pattern and symptomless behavior. The differential diagnosis between AOT and other odontogenic tumours, such as ameloblastoma, should be well conducted in order to avoid extensive ablative surgery. This report presents an unusual case of an 11-year-old male patient who referred to the oral surgeon due to a significant painless gingival swelling in the anterior mandible. A panoramic X-ray revealed a round radiolucid image of an intraosseous lesion with well defined boards and related to the left lateral incisor and left canine. The Computerized Tomography was performed and the sagittal sections revealed a tooth image in contact with the inferior board of the tumour. Additionally, the coronal sections showed the presence of a tooth inside the lesion. Several calcifying nodules could be distinguished within the cystic area. The clinical diagnostic hypothesis was of calcifying epithelium odontogenic tumour but the histological sections were consistent with AOT. The tumour was enucleated under local anesthesia. After one year follow-up there were no signs of reoccurrence. With respect to the distinguishing tumour enlargement and localization in the lower jaw, the reported case is an uncommon example of AOT.