Oral Health Cooperative Research Centre, Melbourne Dental School, The University of Melbourne, Carlton, Victoria, Australia.
Department of Fundamental Dental and Medical Sciences, Kulliyyah of Dentistry, International Islamic University Malaysia, Kuantan, Pahang, Malaysia.
Carcinogenesis. 2019 Mar 12;40(1):184-193. doi: 10.1093/carcin/bgy137.
Microbial infection has been shown to involve in oral carcinogenesis; however, the underlying mechanisms remain poorly understood. The present study aimed to characterize the growth of oral microorganisms as both monospecies and polymicrobial biofilms and determine the effects of their products on oral keratinocytes. Candida albicans (ALC3), Actinomyces naeslundii (AN) and Streptococcus mutans (SM) biofilms or a combination of these (TRI) were grown in flow-cell system for 24 h. The biofilms were subjected to fluorescent in situ hybridization using species-specific probes and analysed using confocal laser scanning microscopy. The effluent derived from each biofilm was collected and incubated with malignant (H357) and normal (OKF6) oral keratinocytes to assess extracellular matrix adhesion, epithelial-mesenchymal transition (EMT) and cytokines expression. Incubation of OKF6 with ALC3 and TRI effluent significantly decreased adhesion of the oral keratinocyte to collagen I, whereas incubation of H357 with similar effluent increased adhesion of the oral keratinocyte to laminin I, significantly when compared with incubation with artificial saliva containing serum-free medium (NE; P < 0.05). In OKF6, changes in E-cadherin and vimentin expression were not consistent with EMT although there was evidence of a mesenchymal to epithelial transition in malignant oral keratinocytes incubated with AN and SM effluent. A significant increase of pro-inflammatory cytokines expression, particularly interleukin (IL)-6 and IL-8, was observed when H357 was incubated with all biofilm effluents after 2- and 24-h incubation when compared with NE (P < 0.05). In conclusion, C.albicans, A.naeslundii and S.mutans form polymicrobial biofilms which differentially modulate malignant phenotype of oral keratinocytes.
微生物感染已被证实与口腔癌发生有关；然而，其潜在机制仍知之甚少。本研究旨在描述口腔微生物作为单物种和多物种生物膜的生长情况，并确定其产物对口腔角质细胞的影响。将白色念珠菌 (ALC3)、奈瑟氏放线菌 (AN) 和变形链球菌 (SM) 生物膜或这些生物膜的组合 (TRI) 接种在流动池系统中 24 小时。使用种特异性探针对生物膜进行荧光原位杂交，并使用共聚焦激光扫描显微镜进行分析。收集每种生物膜的流出液，并与恶性 (H357) 和正常 (OKF6) 口腔角质细胞孵育，以评估细胞外基质黏附、上皮-间充质转化 (EMT) 和细胞因子表达。将 OKF6 与 ALC3 和 TRI 流出液孵育显著降低了口腔角质细胞对 I 型胶原的黏附，而将 H357 与类似的流出液孵育则增加了口腔角质细胞对 I 型层粘连蛋白的黏附，与孵育在不含血清的人工唾液 (NE) 中的口腔角质细胞相比，差异有统计学意义 (P<0.05)。在 OKF6 中，E-钙黏蛋白和波形蛋白表达的变化与 EMT 不一致，尽管在与 AN 和 SM 流出液孵育的恶性口腔角质细胞中观察到上皮向间充质转化的证据。当 H357 与所有生物膜流出液孵育 2 小时和 24 小时后，与 NE 相比，观察到促炎细胞因子表达的显著增加，特别是白细胞介素 (IL)-6 和 IL-8 (P<0.05)。综上所述，白色念珠菌、奈瑟氏放线菌和变形链球菌形成多物种生物膜，可不同程度地调节口腔角质细胞的恶性表型。
