大肠正常组织和癌组织自体荧光差异病理学基础

目的：比较胶原Ⅰ、Ⅲ、Ⅳ型在大肠正常组织和癌组织的分布差异，分析组织癌变后胶原的改变对自体荧光产生的影响。方法：采用免疫组化技术，半定量计分分析Ⅰ、Ⅲ、Ⅳ型胶原亚型在２６例病人正常和腺癌组织中的分布差异。结果：正常组织的基底膜呈现很强的Ⅳ型胶原抗体阳性反应，在基底膜形成较粗的环形染色带；Ⅰ型和Ⅲ型胶原抗体反应在细胞外基质呈连续的细丝纤维样，紧贴基底膜，间质中染色较基底膜稍深。癌组织Ⅳ型胶原抗体反应在癌巢周边为阴性，或仅在残存的基底膜有片断的阳性反应；Ⅰ型和Ⅲ型胶原在癌巢周边的反应呈阴性或不连续性的阳性，但癌间质的阳性反应较正常间质内明显。癌细胞浸润深肌层后癌巢周边间质内三种胶原抗体反应均呈阴性。Ⅰ型、Ⅲ型和Ⅳ型在正常组织和癌组织中的分布存在十分显著性差异（Ｐ〈０．００１），但在不同分化程度腺癌的分布上无明显差异

Differences in Distribution of Collagen Types I, III and IV between Normal and Carcinomatous Colorectal Tissues

Objective: To compare the distribution of collagen type I, III and IV in mucosa of normal and carcinomatous colorectal tissues and to analyze the influence of changed collagen on autofluorescence after cancerization. Methods: Using immunohistochemical technique with monoclonal anti-collagen type I, III and IV, differences in distribution in extracellular matrix of three types collagen between normal and carcinomatous solorectal tissues from 26 patients were measured with semiquantitative score methods. Results: In normal mucosa, the epithelial basement membrane showed an intense positive reaction for monoclonal anti-collagen type IV and an intensively stained ring band was formed around the grand basement membrane. Collagen type I and III formed ring-like structures apparently representative of fibrillar collagen immediately adjacent to the epithelial basement membrane, and staining in the connective tissue stroma seemed to more abundant than in basement membrane. In carcinomatous mucosa, immunoreaction of collagen type IV around most of the carcinomatous cell nest was negative, and only remnants of positively were seen at the site of the former membrane. The ring-like structures formed by collagen types I and III immediately adjacent to the basement membrane were degraded. Showing only remnants of these structures. In contrast, positive reaction in carcinomatous stroma was more intensity than in normal stroma. When the cancerous cell invaded into the muscle layer, immunoreaction of collagen types I and III in stroma around the cancerous cell nest were negative. There were significant differences in distribution of types I, III and IV between normal and carcinomatous tissues ( P <0.001). Conclusions: The main collagen located in basement membrane was type IV. After colorectal cancer occurring, collagen type IV in basement membrane and stroma decreased significantly, and collagen types I and III decreased around carcinomatous cell nest but increased in carcinomatous stroma. Collagen type IV was the main source of laser-induced autofluorescence in colorectal basement membrane. After colorectal cancer occurring, the degradation of collagen type IV in basement membrane and stroma was one of the main causes of reduced intensity of laser-induced autoflurescence in carcinomatous tissues.