E‐cadherin downregulation and Twist overexpression since early stages of oral carcinogenesis

There is some evidence of Twist participation in oral carcinogenesis; however, little is known about its interaction with E‐cadherin in oral squamous cell carcinoma (OSCC) development. This experimental study included an immunohistochemical analysis of Twist and E‐cadherin proteins in paraffin‐embedded specimens of oral leukoplakia (OL), OSCC, and normal oral mucosa. In addition, it was also performed a Western blot and double‐immunofluorescence analysis of Twist and E‐cadherin expression in OSCC cell lines. Significant differences in Twist and E‐cadherin immunoexpression were observed between normal oral mucosa and OL, with an inverse relation since the earliest stages of oral dysplasia (r = ?0,512; P < 0.001). Western blot and double‐immunofluorescence analysis showed differences in Twist and E‐cadherin expression among human oral keratinocytes and OSCC cell lines suggesting that downregulation of E‐cadherin occurs in a dependent manner of Twist in OSCC. Our results showed a possible value of Twist and E‐cadherin in the prediction of risk of oral epithelium malignant transformation.     

A study of phosphorylated ERK1/2 and COX‐2 in early stage (T1–T2) oral squamous cell carcinomas

Background: Histomorphological grading at the invasive front of oral squamous cell carcinomas (OSCCs) may provide useful prognostic information. In the present study, we investigated the presence and prognostic value of activated phosphorylated extracellular signal‐regulated kinases 1 and 2 (p‐ERK1/2) and cyclo‐oxygenase‐2 (COX‐2) both at the invasive front and in central/superficial parts of OSCCs. Methods: Using immunohistochemistry, we assessed the presence of p‐ERK1/2 and COX‐2 in 53 early stage OSCCs. Clinical data were recorded prospectively. The end point was disease‐free survival. Results: p‐ERK1/2 staining was present in almost all tumours. The staining was mostly nuclear in the cells of the invasive front and either nuclear or nuclear/cytoplasmic in central/superficial tumour parts. COX‐2 was observed in almost all tumours (98%) and the staining was often restricted to focal areas. Most tumours were COX‐2 negative at the invasive front. The lowest P‐value in survival analyses was P = 0.06 for p‐ERK1/2 at the invasive front. COX‐2, the histomorphological grading systems and TNM stage were of no prognostic value. Conclusion: p‐ERK1/2 was present in almost all tumours and p‐ERK1/2 may be a prognostic marker at the invasive front of OSCCs. In early stage OSCCs, most tumours did not express COX‐2 at the invasive front.     

Skp2蛋白在口腔鳞癌中的表达及其与c-myc、p27蛋白表达的关系

目的:研究Skp2、c-myc及p27蛋白在口腔鳞癌组织中的表达.方法:免疫组化检测Skp2、c-myc及p27蛋白在54例口腔鳞癌和15例正常口腔黏膜组织中的表达.结果:口腔鳞癌组织中Skp2、c-myc阳性表达率分别为35.19%(19/54)和38.89%(21/54),显著高于正常口腔黏膜组织6.67%(1/15)、6.67%(1/15)(P＜0.05);p27阳性表达率为55.56%(30/54)显著低于正常口腔黏膜组织86.67%(13/15)(P＜0.05);Skp2的表达与口腔鳞癌的临床分期、病理分级、淋巴结转移显著相关(P＜0.05),与年龄、性别、肿瘤部位等因素无关(P＞0.05);口腔鳞癌中Skp2与c-myc表达呈正相关(r=0.562,P＜0.01);与p27蛋白的表达呈负相关(r=-0.532,P＜0.01).结论:Skp2蛋白过表达在口腔鳞癌的发生及发展中起重要作用;并可能与c-myc蛋白有协同作用,Skp2蛋白过表达与靶蛋白p27蛋白降解有关,联合检测Skp2、c-myc及p27蛋白的表达有助于综合评估口腔鳞癌的生物学行为.     

Multiplexed immunobead‐based assay for detection of oral cancer protein biomarkers in saliva

Objective: For clinical applications of biomarkers, there is a need for multiplex assays using high throughput platforms. The objective of this study was to determine the efficacy of Luminex Multianalyte Profiling (xMAP) technology for measurement of salivary proteins and to evaluate whether multiplex assays are as effective as single‐plex assays and enzyme‐linked immunosorbent assay (ELISA). Results: The average levels of interleukin‐8 (IL‐8) from the single‐plex assay were 3313.2 ± 3759.8 pg ml^?1 [oral squamous cell carcinoma (OSCC), n = 20] and 1061.7 ± 1978.8 pg ml^?1 (control, n = 20). The IL‐1β average levels from the single‐plex assay were 945.2 ± 1134.8 pg ml^?1 (OSCC, n = 20) and 314.2 ± 444.8 pg ml^?1 (control, n = 20). The average levels of IL‐8 from the multiplex assay were 2834.9 ± 3385.6 pg ml^?1 (OSCC, n = 20) and 947.3 ± 2036.8 pg ml^?1 (control, n = 20). The IL‐1β average levels from the multiplex assay were 1013.5 ± 1221.1 pg ml^?1 (OSCC, n = 20) and 376.3 ± 576.3 pg ml^?1 (control, n = 20). The correlation coefficient between Luminex and ELISA assay for IL‐8 (n = 19) and IL‐1β (n = 19) was 0.91 and 0.84, respectively. Conclusion: Luminex xMAP single‐plex and multiplex assays are as effective as ELISA assays for quantification of proteins in saliva. Both IL‐8 and IL‐1β were expressed at significantly higher levels in OSCC subjects than in the matched healthy control subjects.