Metaplasia is the replacement of one differentiated somatic cell type with another differentiated somatic cell type in the same tissue. Typically, metaplasia is triggered by environmental stimuli, which may act in concert with the deleterious effects of microorganisms and inflammation. The cell of origin for intestinal metaplasia in the oesophagus and stomach and for pancreatic acinar–ductal metaplasia has been posited through genetic mouse models and lineage tracing but has not been identified in other types of metaplasia, such as squamous metaplasia. A hallmark of metaplasia is a change in cellular identity, and this process can be regulated by transcription factors that initiate and/or maintain cellular identity, perhaps in concert with epigenetic reprogramming. Universally, metaplasia is a precursor to low-grade dysplasia, which can culminate in high-grade dysplasia and carcinoma. Improved clinical screening for and surveillance of metaplasia might lead to better prevention or early detection of dysplasia and cancer.

中文翻译：

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化生：组织损伤适应和不典型增生-癌症序列的前兆

化生是在同一组织中用一种分化的体细胞类型替换另一种分化的体细胞类型。通常，化生是由环境刺激触发的，环境刺激可能与微生物和炎症的有害作用协同作用。食管和胃的肠上皮化生以及胰腺腺泡-导管上皮化生的起源细胞已通过遗传小鼠模型和谱系溯源定位，但尚未在其他类型的上皮化中被发现，例如鳞状上皮化生。化生的标志是细胞身份的改变，该过程可以由启动和/或维持细胞身份的转录因子调节，也许与表观遗传重编程协同作用。普遍来说，化生是轻度不典型增生的前兆，最终可导致严重的不典型增生和癌变。改善对生化的临床筛查和监测可能会导致更好地预防或早期发现不典型增生和癌症。