Department of Pathological Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury in Olsztyn, Oczapowskiego 13, 10-719, Olsztyn, Poland.
BMC Vet Res. 2023 Feb 10;19(1):42. doi: 10.1186/s12917-023-03604-5.
Feline injection site fibrosarcoma is an aggressive and infiltrative tumour arising in the background of chronic inflammation. The aim of this study was to evaluate the expression of metallothionein (I-II) in feline injection site fibrosarcomas and to assess its possible relationships with Ki67 index, inflammation score and tumour grade. The study included 40 feline fibrosarcomas, located in the common injection sites (i.e., interscapular area, thigh, flank), constituting archival diagnostic specimens collected between 2019-2020. Tumours were graded histologically according to the newly proposed soft-tissue sarcoma grading system in cats. Immunohistochemistry was performed to evaluate the expression of Ki67 and metallothionein in tumour cells.
The cytoplasmic and sometimes nuclear expression of metallothionein was observed in all tumours grade I, 66.67% of tumours grade II and 55% of tumours grade III. The expression of metallothionein was negatively correlated with tumour grade and inflammation score, while the Ki67 index was positively correlated with tumour grade, inflammation score and necrosis score.
The downregulation of MT expression in feline injection site fibrosarcomas seems to be connected with an increase in the inflammatory infiltration, hence tumour progression. This is the first study describing metallothionein expression in feline injection site fibrosarcomas.
猫注射部位纤维肉瘤是一种在慢性炎症背景下发生的侵袭性和浸润性肿瘤。本研究旨在评估金属硫蛋白（I-II）在猫注射部位纤维肉瘤中的表达，并评估其与 Ki67 指数、炎症评分和肿瘤分级的可能关系。该研究纳入了 40 例位于常见注射部位（即肩胛间区、大腿、侧腹）的猫纤维肉瘤，这些肿瘤是 2019-2020 年间收集的存档诊断标本。根据新提出的猫软组织肉瘤分级系统对肿瘤进行组织学分级。采用免疫组织化学方法评估肿瘤细胞中 Ki67 和金属硫蛋白的表达。
所有 I 级肿瘤、66.67%的 II 级肿瘤和 55%的 III 级肿瘤均观察到金属硫蛋白的细胞质和（有时）核表达。金属硫蛋白的表达与肿瘤分级和炎症评分呈负相关，而 Ki67 指数与肿瘤分级、炎症评分和坏死评分呈正相关。
猫注射部位纤维肉瘤中 MT 表达的下调似乎与炎症浸润的增加有关，从而导致肿瘤进展。这是首次描述猫注射部位纤维肉瘤中金属硫蛋白表达的研究。
