Expression of NF-κB and IL-6 in oral precancerous and cancerous lesions: An immunohistochemical study.

BACKGROUND: The purpose of this study was to evaluate the immunohistochemical expression of NF-κB and IL-6 in oral premalignant and malignant lesions and to investigate their possible correlation with the presence of subepithelial inflammation. MATERIAL AND METHODS: Thirty two oral premalignant lesions, clinically compatible with leukoplakia or erythroplakia, were investigated. Microscopically, 11 of them showed hyperkeratosis and acanthosis (epithelial hyperplasia) and 21 showed dysplasia of varying degrees. Nine cases of OSCC and four control cases of normal oral mucosa were also included in the study. Immunohistochemical staining with NF-κB (p65) and IL-6 was performed. IL-6 and nuclear NF-κB staining were assessed as positive or negative. For cytoplasmic localization of NF-κB, a total score combining intensity and percentage of positive epithelial cells was additionally calculated. The presence of inflammation was also recorded. RESULTS: Intensity and total scores for NF-κΒ cytoplasmic immunostaining showed a statistically significant gradual increase from normal mucosa to OSCC (p=0.012 and p=0.026 respectively). Non-statistically significant increased NF-κΒ nuclear localization was detected in dysplasias and OSCCs. Positive statistical correlation was detected between the presence of inflammation and IL-6 expression (p=0.015). No correlation between NF-κΒ and IL-6 was detected. CONCLUSIONS: NF-κΒ is activated in the early stages of oral carcinogenesis. IL-6 may have an NF-κΒ-independent role, possibly through regulation of the inflammatory response.

Immunohistochemical expression of Bcl-2 and Ki-67 in oral lichen planus and leukoplakia with different degrees of dysplasia.

OBJECTIVES: Oral lichen planus (OLP) is a chronic inflammatory disease of unknown cause. Malignant transformation in OLP lesions may be favored by changes in the expression of proteins that regulate cell proliferation and apoptosis. This study aimed to investigate these issues by immunohistochemical staining for Bcl-2 and Ki-67 and by correlating histopathological findings in samples from lesions of OLP and leukoplakia with epithelial dysplasia. METHODS: Data for patients with OLP or leukoplakia with moderate or severe epithelial dysplasia recorded during 2006-2011 were retrospectively reviewed. The study samples represented 37 subjects with OLP (n = 14), leukoplakia with moderate (n = 8) or severe (n = 6) epithelial dysplasia, and normal buccal mucosa (controls, n = 9). New sections were subjected to histological examination and immunohistochemistry for Bcl-2 and Ki-67 in the basal layer, suprabasal layer, and inflammatory infiltrate, respectively. RESULTS: All basal layer sections stained either negative or positive in <10% of cells for Bcl-2 in OLP (92.9% and 7.1%, respectively) and control (77.8% and 22.2%, respectively) samples. In leukoplakia, 85.7% of sections indicated positivity in <10% of cells, and 14.3% indicated positivity in 10-26% of cells. Most OLP (42.9%) and leukoplakia (64.3%) sections stained positive for Ki-67 in >50% of cells. All suprabasal sections stained either negative or positive in <10% of cells for Bcl-2 in OLP (92.9% and 7.1%, respectively), leukoplakia (42.9% and 57.1%, respectively), and control (88.9% and 11.1%, respectively) samples. Suprabasal staining for Ki-67 was negative or positive in <10% of cells in OLP (14.3% and 85.7%, respectively), leukoplakia (7.1% and 92.9%, respectively), and controls (88.9% and 11.1%, respectively). Staining for Bcl-2 in inflammatory infiltrate in OLP was positive in 92.9% of sections. CONCLUSIONS: Expression of Bcl-2 may play a dual role in tumor development and progression. Increased cell proliferation in the epithelium may present a predisposition to cancer in OLP. The expression of Ki-67 can be considered as an adjunct marker for proliferative activity in lesions with malignant potential. The prognostic value of these immunomarkers in the evaluation of precancerous oral lesions requires further investigation.

Correlation of ECM1 expression level with the pathogenesis and metastasis of laryngeal carcinoma.

OBJECTIVE: To investigate the expression of extracellular matrix protein 1 (ECM1) in benign laryngeal lesions, precancerous lesions and malignant laryngeal lesions and analyze the clinical significance of ECM1 changes in the pathogenesis and metastasis of laryngeal carcinoma. METHODS: A total of 46 patients with laryngeal lesions were recruited with a median age of 48.2 years (range: 33-67 years). Among these patients, 29 had laryngeal carcinoma (12 with metastasis and 17 without metastasis), 8 had benign laryngeal lesions and 9 had precancerous laryngeal lesions (laryngeal leukoplakia). Immunofluorescence staining was employed to detect the protein expression of ECM1 in benign laryngeal lesions, laryngeal leukoplakia and malignant laryngeal lesions; RT-PCR was used to measure the mRNA expression of ECM1 in laryngeal carcinoma and benign laryngeal lesions. RESULTS: ECM1 expression was detected in 25% (2/8) of patients with benign laryngeal lesions, 78% (7/9) of patients with precancerous laryngeal lesions, and 100% (29/29) of patients with laryngeal carcinoma. Among the laryngeal carcinoma patients, high ECM1 expression (+++) was found in 64.7% (11/17) of patients without lymph node metastasis and 91.7% (11/12) of patients with lymph node metastasis. Increased ECM1 expression was found in laryngeal carcinoma when compared with other laryngeal lesions and the ECM1 expression in patients with metastasis was significantly higher than that patients without metastasis (P<0.01). RT-PCR showed that the mRNA expression of ECM-1 in laryngeal carcinoma was markedly higher than that in benign laryngeal lesions. CONCLUSION: ECM1 expression is in an increasing order in benign laryngeal lesions, precancerous laryngeal lesions and malignant laryngeal lesions. Meanwhile, the metastatic laryngeal carcinoma has higher ECM1 expression than laryngeal carcinoma without metastasis. Our findings suggest that ECM1 plays promotive roles in the occurrence, development and metastasis of laryngeal carcinoma.

Epithelial cell proliferative activity and oral cancer progression.

Accurate, predictive assessment of the behaviour and progression of oral cancers and precancers remains elusive in clinical practice. Archival tissue specimens from 10 previously treated patients with oral lesions of known clinical outcome (3 years post-treatment) were re-examined histopathologically, and proliferative cell labelling indices (LIs) determined for Ki67, cyclin A and histone mRNA cell cycle markers. While histone mRNA labelling ultimately proved unreliable, both Ki67 and cyclin A LIs demonstrated a clear trend for enhanced labelling to occur in increasingly dysplastic and neoplastic tissue, with particular emphasis on suprabasal labelling in abnormal tissue. Perhaps of greatest significance was the observation of increased LIs and suprabasal labelling in lesions with poor clinical outcome, such as patients developing recurrent disease or cervical lymph node metastasis. Measurement of cell proliferative activity in individual oral epithelial dysplastic lesions or invasive squamous cell carcinomas may thus provide unique, predictive information on clinical outcome.

Expression of granulocyte colony-stimulating factor receptor and platelet-derived endothelial cell growth factor in oral and oropharyngeal precancerous lesions.

Epithelial hyperplasia and dysplasia have been diagnosed as precancerous lesions and have been discussed in relationship to carcinogenesis. We analyzed the immunohistochemical expression of granulocyte colony-stimulating factor receptor (G-CSFR) and platelet-derived endothelial cell growth factor (PD-ECGF) in oral and oropharynx; 33 samples of normal epithelium, 28 samples of hyperplasia, 16 samples of dysplasia and 58 samples of squamous cell carcinoma. Also, we examined mean vessel density (MVD) by using CD34 staining and proliferating cell nuclear antigen (PCNA) staining. Dysplasia and head and neck Squamous Cell Carcinoma (SCC) exhibited higher G-CSFR expression and MVD than normal or hyperplastic epithelium (p <0.01). In the PD-ECGF staining, significant differences were found between SCC and normal epithelium, hyperplasia and dysplasia (p<0.001). In dysplasia and hyperplasia, PD-ECGF expression was significantly correlated with PCNA expression (r=0.345, p=0.025), however it was not correlated with the MVD. G-CSFR expression was not correlated with either PCNA or MVD. These results suggest that G-CSFR and PD-ECGF might be concerned with different carcinogenesis pathways of the squamous cells in the oral region and that PD-ECGF may be concerned with epithelial proliferation rather than angiogenesis.

The proliferative activity in oral epithelial dysplasia analyzed by proliferating cell nuclear antigen immunostaining and argyrophilic nucleolar organizer region staining.

The proliferative activity of leukoplakia without dysplastic change (LP), epithelial dysplasia (ED), and squamous cell carcinoma (SCC) in the oral mucosa was examined by means of proliferating cell nuclear antigen (PCNA) immunostaining, silver-binding argyrophilic nucleolar organizer region (AgNOR) staining, and the frequency of mitotic figures. Significant differences in the labeling index of PCNA immunostaining (PI) and mitotic index (MI) were noted between LP and ED and between ED and SCC. The mean numbers of AgNORs (AI) significantly differed between ED and SCC. There was a significant positive correlation between PI and MI in samples of ED. However, there was no significant correlation between AI and other indexes. The number and the distribution of PCNA-positive cells in ED varied among samples. Five samples with higher PI and MI indexes than the mean values were selected from those of dysplasia based on the correlation between PI and MI. Their histological features symptomatic of oral ED as defined by the World Health Organization (WHO) Collaborating Centre in 1978, were investigated and compared with 10 samples with lower indexes. Histological findings, such as "loss of polarity of the basal cells," "an increased nuclear-cytoplasmic ratio," "cellular pleomorphism," and "enlarged nucleoli," were significant histological features of these five samples. This study showed that the four histological components described previously and the increased number of mitotic figures used as the index of proliferating activity were the main histological components related to severe ED of oral mucosa. They will provide a useful means of deciding the histopathological grade of oral ED.