DNA aneuploidy relationship with patient age and tobacco smoke in OPMDs/OSCCs

The aim of this study was to investigate the relationship between tobacco smoke habit, patient age, DNA aneuploidy and genomic DNA copy number aberrations (CNAs) in oral potentially malignant disorder (OPMD) and oral squamous cell carcinoma (OSCC) patients. DNA aneuploidy was detected by high-resolution DNA flow cytometry (hr DNA-FCM) on DAPI stained nuclei obtained from multiple tissue samples from OPMDs/OSCCs in 220 consecutive patients. Nuclear genomic aberrations were determined in a subset of 65 patients by genome-wide array comparative genomic hybridization (aCGH) using DNA extracted from either diploid or aneuploid nuclei suspension sorted by FCM. DNA aneuploidy and mean nuclear genomic aberrations were associated with patients’ age. In particular, DNA aneuploidy strongly associated with age in non-smoker OPMDs/OSCCs patients. OSCCs from smokers showed a lower prevalence of DNA aneuploidy compared to OSCCs from non-smokers. A higher occurrence of DNA aneuploidy (particularly in smokers’ OPMDs) was observed in patients characterized by involvement of a single oral subsite. Our study suggests that: 1) DNA aneuploidy in non-smokers is mainly related to aging; 2) OPMDs/OSCCs involving multiple oral subsites in smokers are less likely to develop DNA aneuploidy compared to non-smokers; 3) OSCC development is characterized by both CIN and CIN-independent mechanisms and that the latter are more relevant in smokers. This study provides evidence that DNA diploid OPMDs may be considered at lower risk of cancerization than DNA aneuploid ones in non-smokers but not in smokers.

本研究旨在探讨烟草吸烟习惯、患者年龄、DNA非整倍体（DNA aneuploidy）与基因组DNA拷贝数变异（CNAs）在口腔潜在恶性疾患（OPMD）及口腔鳞状细胞癌（OSCC）患者中的关联。本研究对220例连续入组患者的口腔潜在恶性疾患/口腔鳞状细胞癌多组织样本中获取的DAPI染色细胞核，采用高分辨率DNA流式细胞术（hr DNA-FCM）检测DNA非整倍体。对65例患者的亚组样本，通过全基因组阵列比较基因组杂交（aCGH），对经流式细胞术分选的二倍体或非整倍体细胞核悬液提取的DNA进行检测，以分析细胞核基因组变异情况。DNA非整倍体与平均细胞核基因组变异均与患者年龄相关；具体而言，在非吸烟的口腔潜在恶性疾患/口腔鳞状细胞癌患者中，DNA非整倍体与年龄存在显著关联。与非吸烟口腔鳞状细胞癌患者相比，吸烟患者的口腔鳞状细胞癌中DNA非整倍体检出率更低。在仅累及单个口腔亚位点的患者中，DNA非整倍体（尤其在吸烟的口腔潜在恶性疾患患者中）发生率更高。本研究提示：1）非吸烟者的DNA非整倍体主要与衰老相关；2）与非吸烟者相比，吸烟患者中累及多个口腔亚位点的口腔潜在恶性疾患/口腔鳞状细胞癌发生DNA非整倍体的可能性更低；3）口腔鳞状细胞癌的发生兼具染色体不稳定（CIN）与非染色体不稳定机制，且后者在吸烟者中更为关键。本研究证实，在非吸烟者中，DNA二倍体的口腔潜在恶性疾患癌变风险低于DNA非整倍体病变，但在吸烟者中并非如此。