Usefulness of tumor markers in veterinary medicine

为了展示肿瘤标记物在兽医中的作用，我们在小动物实践中对患有肿瘤疾病的狗和猫进行了各种肿瘤标记物的检测。在本研究的两年中，我们调查了6类肿瘤标志物的用途：(1)血清(血浆)肿瘤标志物，(2)细胞内端粒酶和端粒酶逆转录酶，(3)P-53和MDM2的表达和p53基因突变，(4)细胞克隆性，(5)染色体脱落，(6)与多药耐药相关的P-糖蛋白(P-gp)。本研究的主要结果如下：1.测定了犬乳腺肿瘤组织中端粒长度和细胞内端粒酶活性，发现端粒酶活性可作为肿瘤标志物。2.对犬和猫自然发生的肿瘤组织中的P53基因序列进行检测，发现约50%的犬肿瘤组织中存在P53基因突变，从而发现P53基因突变可导致…更多的e被用作狗的肿瘤标记物。此外，大量的犬肿瘤中存在MDM2(一种抑制P-53的蛋白)的过度表达，这可能是一种新的肿瘤标志物。3.利用外源性猫白血病病毒(FeLV)对肿瘤、骨髓和淋巴组织的外周血样和活检标本进行Southern杂交分析。因此，在肿瘤疾病(白血病和骨髓增生异常综合征，MDS)中检测到了单克隆性或寡克隆性细胞群，发现细胞克隆性可作为FeLV感染猫的一种新的肿瘤标志物。4.测定了犬和猫多药耐药(MDR)基因编码P-gp的核苷酸序列。用抗P-gp(C219)单抗分别用RT-PCR和免疫组织化学方法检测肿瘤细胞中MDR RNA和P-gp蛋白的表达。通过联合应用抗肿瘤药物和P-gp抑制剂，化疗的疗效得到了改善。较少

In order to show the usefulness of tumor markers in veterinary medicine, we measured a variety of tumor markers in dogs and cats with neoplastic diseases in small animal practice. During the 2 years for the present study, we investigated the usefulness of tumor markers classified into 6 categories : (1) serum (plasma) tumor marker, (2) intracellular telomerase and telomerase reverse transcriptase, (3) expression of P-53 and MDM2 and mutation of p53 gene, (4) cell clonarity, (5) chromosome abberation, and (6) P-glycoprotein (P-gp) associated with multidrug resistance. Major results of the present study are as follows.1.We measured the telomere length and intracellular telomerase activity in canine mammary tumors and found that telomerase activity could be used as a tumor marker.2.We examined the sequence of p53 gene in naturally occurring tumors in dogs and cats and found that p53 gene was mutated in approximately 50% of the dog tumors, therefore, found that mutation of p53 gene could b … More e used as a tumor marker in dogs. Moreover, a large number of dog tumors were shown to have an overexpression of MDM2 (a protein inhibiting P-53) which could be a candidate of new tumor marker.3.Southern blot analysis using exogenous feline leukemia virus (FeLV) was carried out in the peripheral blood samples and biopsy specimens of tumors, bone marrows and lymph modes. As a result, monoclonal or oligoclonal cell population was detected in neoplastic deseases (leukemia and myelodysplastic syndrome, MDS) and it was found that the cell clonality could be used as a new tumor marker in FeLV-infected cats.4.Nucleotide sequences of canine and feline mdr (multidrug resistance) genes that encodes P-gp were determined. Expressions of mdr RNA and P-gp protein were examined by RT-PCR and immunohistochemistry using a monoclonal antibody directed P-gp (C219), respectively, in tumor cells. By the treatment with antineoplastic drugs in conjunction with P-gp inhibitor, response to the chemotherapy was shown to be improved. Less