Departamento de Odontologia Conservadora, Faculdade de Odontologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brasil.
Departamento de Patologia, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brasil.
J Appl Oral Sci. 2020;28:e20190532. doi: 10.1590/1678-7757-2019-0532. Epub 2020 Apr 27.
Oral leukoplakia (OL) is a white lesion of an indeterminate risk not related to any excluded (other) known diseases or disorders that carry no increased risk for cancer. Many biological markers have been used in an attempt to predict malignant transformation; however, no reliable markers have been established so far. Objective To evaluate cell proliferation and immortalization in OL, comparing non-dysplastic (Non-dys OL) and dysplastic OL (Dys OL). Methodology This is a cross-sectional observational study. Paraffin-embedded tissue blocks of 28 specimens of Non-dys OL, 33 of Dys OL, 9 of normal oral mucosa (NOM), 17 of inflammatory hyperplasia (IH), and 19 of oral squamous cell carcinomas (OSCC) were stained for Ki-67 and BMI-1 using immunohistochemistry. Results A gradual increase in BMI-1 and K-i67 expression was found in oral carcinogenesis. The immunolabeling for those markers was higher in OSCC when compared with the other groups (Kruskal-Wallis, p<0.05). Ki-67 expression percentage was higher in OL and in IH when compared with NOM (Kruskal-Wallis/Dunn, p<0.05). Increased expression of BMI-1 was also observed in OL when compared with NOM (Kruskal-Wallis/Dunn, p<0.05). No differences were observed in expression of both markers when non-dysplastic and dysplastic leukoplakias were compared. A significant positive correlation between Ki-67 and BMI-1 was found (Spearman correlation coefficient, R=0.26, p=0.01). High-grade epithelial dysplasia was associated with malignant transformation (Chi-squared, p=0.03). Conclusions These findings indicate that BMI-1 expression increases in early oral carcinogenesis and is possibly associated with the occurrence of dysplastic changes. Furthermore, our findings indicate that both Ki-67 and BMI-1 are directly correlated and play a role in initiation and progression of OSCC.
口腔白斑病（OL）是一种非特定风险的白色病变，与任何排除的（其他）已知疾病或病症无关，这些疾病或病症不会增加癌症的风险。许多生物标志物已被用于试图预测恶性转化；然而，迄今为止尚未建立可靠的标志物。目的评估 OL 中的细胞增殖和永生化，比较非发育不良（非发育 OL）和发育不良 OL（发育不良 OL）。方法这是一项横断面观察性研究。使用免疫组织化学方法对 28 例非发育不良 OL、33 例发育不良 OL、9 例正常口腔黏膜（NOM）、17 例炎症性增生（IH）和 19 例口腔鳞状细胞癌（OSCC）的石蜡包埋组织块进行 Ki-67 和 BMI-1 染色。结果在口腔癌变过程中发现 BMI-1 和 K-i67 表达逐渐增加。与其他组相比，OSCC 中这些标志物的免疫标记更高（Kruskal-Wallis，p<0.05）。与 NOM 相比，OL 和 IH 中的 Ki-67 表达百分比更高（Kruskal-Wallis/Dunn，p<0.05）。与 NOM 相比，OL 中也观察到 BMI-1 表达增加（Kruskal-Wallis/Dunn，p<0.05）。非发育不良和发育不良性白斑之间比较时，两种标志物的表达均无差异。Ki-67 和 BMI-1 之间存在显著正相关（Spearman 相关系数，R=0.26，p=0.01）。高级上皮发育不良与恶性转化相关（卡方检验，p=0.03）。结论这些发现表明，BMI-1 的表达在口腔癌发生的早期增加，并且可能与发育不良变化的发生有关。此外，我们的研究结果表明，Ki-67 和 BMI-1 均直接相关，在 OSCC 的发生和发展中起作用。
