Faro Thamirys A S, de Oliveira Edivaldo H C
Programa de Pós Graduação em Genética e Biologia Molecular, Universidade Federal do Pará, Belém, Pará, Brazil.
Laboratório de Citogenômica e Mutagênese Ambiental, SEAMB, Instituto Evandro Chagas Ananindeua, Belém, Pará, Brazil.
Anim Genet. 2023 Feb;54(1):82-89. doi: 10.1111/age.13260. Epub 2022 Oct 19.
Cancer is a group of complex diseases resulting from the accumulation of genetic and epigenetic changes affecting control and activity of several genes, especially those involved in cell differentiation and growth processes, leading to an abnormal proliferation. When the disease reaches an advanced stage, cancer can lead to metastasis in other organs. Interestingly, recent studies have shown that some types of cancer spread not only through the body, but also can be transmitted among individuals. Therefore, these cancers are known as transmissible tumors. Among the three types of transmissible tumors that occur in nature, the canine transmissible venereal tumor (CTVT) is known as the oldest cancer in the world, since it was originated from a single individual 11 000 years ago. The disease has a worldwide distribution, and its occurrence has been documented since 1810. The CTVT presents three types of cytomorphological classification: lymphocytoid type, mixed type, and plasmacytoid type, the latter being chemoresistant due to overexpression of the ABCB1 gene, and consequently increase of the P-glycoprotein. More knowledge about the epidemiology and evolution of CTVT may help to elucidate the pathway and form of the global spread of the disease.
癌症是一组复杂的疾病，由影响多个基因的控制和活性的遗传和表观遗传变化积累所致，尤其是那些参与细胞分化和生长过程的基因，从而导致异常增殖。当疾病发展到晚期时，癌症可导致转移至其他器官。有趣的是，最近的研究表明，某些类型的癌症不仅会在体内扩散，还可能在个体之间传播。因此，这些癌症被称为可传播肿瘤。在自然界中出现的三种可传播肿瘤类型中，犬传染性性病肿瘤（CTVT）被认为是世界上最古老的癌症，因为它起源于11000年前的一个个体。这种疾病在全球范围内分布，自1810年以来就有其发病记录。CTVT呈现三种细胞形态学分类：淋巴细胞样型、混合型和浆细胞样型，后者由于ABCB1基因的过度表达而具有化疗抗性，从而导致P-糖蛋白增加。更多关于CTVT流行病学和进化的知识可能有助于阐明该疾病全球传播的途径和形式。
