传染性肿瘤研究进展

传染性肿瘤是一类以活细胞形式在个体间异体传播的肿瘤。至今已发现并确定4种,即犬类生殖器传染性肿瘤(Canine transmissible venereal tumor, CTVT)、袋獾面部肿瘤(Tasmanian devil facial tumor disease, DFTD)、海螂血液传染性肿瘤(Soft-shell clams leukemia, SSCL)及仓鼠传染性肿瘤(Hamsters reticulum cell sarcoma, HRCS)。过去几十年,在细胞学、组织学、遗传学等方面的研究证明传染性肿瘤是以活细胞进行传播,CTVT是已知的最古老的哺乳动物体细胞系,DFTD来源于施旺细胞,两者均通过下调MHC基因表达逃避宿主免疫识别,而在SSCL中普遍存在一个转座子多拷贝数变异。近几年来,DFTD和CTVT基因组测序工作相继完成,有助于从全基因组水平研究传染性肿瘤的发生、传染和进化机制。本文总结了传染性肿瘤的研究进展,并展望了未来10年内传染性肿瘤的研究热点。

Recent advances in transmissible tumors

Transmissible tumors are a class of tumor that can be transmitted between individuals through living cells. So far, four types of transmissible tumors including canine transmissible venereal tumor (CTVT),Tasmanian devil facial tumor disease (DFTD), soft-shell clams leukemia (SSCL), and hamsters reticulum cell sarcoma (HRCS)have been discovered and identified. In the last decades, these transmissible tumors have been proved to be transmitted through living cells by cytological, histological and genetic studies. CTVT, the oldest mammalian somatic cell line, and DFTD originated from Schwann cell have been reported to avoid immunological recognition by down-regulating MHC expression, while a high copy number of Steamer retrotransposon is commonly exist in SSCL. In recent years, the whole-genome sequencing of CTVT and DFTD have been completed which facilitates studies on the mechanisms of tumorigenesis, transmission and evolution of transmissible tumors at the whole-genome level. In this review, we summarize the recent advances in transmissible tumors and discuss the research focus in next decade.