Department of Pathophysiology and Immunology, Medical University of Graz, Heinrichstrasse 31, A-8010 Graz, Austria.
Anticancer Res. 2009 Nov;29(11):4519-28.
Medullary thyroid carcinoma (MTC), a rare calcitonin-producing tumor, is derived from parafollicular C-cells of the thyroid and is characterized by constitutive Bcl-2 overexpression. The tumor is relatively insensitive to radiation therapy as well as conventional chemotherapy. To date, the only curative treatment is the early and complete surgical removal of all neoplastic tissue. In this study, the antiproliferative and pro-apoptotic effects of fractions obtained from Uncaria tomentosa (Willd.) DC, commonly known as uña de gato or cat's claw were investigated. Cell growth of MTC cells as well as enzymatic activity of mitochondrial dehydrogenase was markedly inhibited after treatment with different fractions of the plant. Furthermore, there was an increase in the expressions of caspase-3 and -7 and poly(ADP-ribose) polymerase (PARP) fraction, while bcl-2 overexpression remained constant. In particular, the alkaloids isopterpodine and pteropodine of U. tomentosa exhibited a significant pro-apoptotic effect on MTC cells, whereas the alkaloid-poor fraction inhibited cell proliferation but did not show any pro-apoptotic effects. These promising results indicate the growth-restraining and apoptotic potential of plant extracts against neuroendocrine tumors, which may add to existing therapies for cancer.
甲状腺髓样癌（MTC）是一种罕见的降钙素产生肿瘤，来源于甲状腺的滤泡旁 C 细胞，其特征是组成性 Bcl-2 过表达。肿瘤对放射治疗和常规化疗相对不敏感。迄今为止，唯一的根治性治疗方法是早期和彻底切除所有肿瘤组织。在这项研究中，研究了钩藤（Willd.）DC 提取物的馏分的抗增殖和促凋亡作用，通常称为猫爪或猫爪。用植物的不同馏分处理后，MTC 细胞的细胞生长和线粒体脱氢酶的酶活性明显受到抑制。此外，caspase-3 和 -7 的表达以及聚（ADP-核糖）聚合酶（PARP）片段增加，而 bcl-2 过表达保持不变。特别是钩藤中的生物碱异坡定碱和翼足素对 MTC 细胞表现出显著的促凋亡作用，而生物碱含量低的馏分抑制细胞增殖，但没有表现出任何促凋亡作用。这些有希望的结果表明植物提取物对神经内分泌肿瘤的生长抑制和凋亡潜力，这可能增加现有的癌症治疗方法。
