管家基因GAPDH在肿瘤与衰老组织中作为内参应慎重

甘油醛-3-磷酸脱氢酶（glyceraldehyde 3-phosphate dehydrogenase，GAPDH）是糖酵解过程中的一个酶，编码该酶的基因为管家基因，几乎在所有组织中呈高水平、恒定表达，常用作蛋白质、RNA、DNA等分子生物学相关实验的标准化内参。但近年来，GAPDH作为内参受到质疑，特别是在肿瘤组织、衰老组织。大量研究证实，GAPDH在多种肿瘤中表达上调，衰老的骨骼肌中下调。其中GAPDH在肿瘤中的高表达可能与肿瘤的侵袭性转移和细胞增殖相关。本文就GAPDH在肿瘤、衰老组织或细胞中的表达情况以及可能机制作一综述，旨在更全面地了解管家基因GAPDH在肿瘤与衰老组织、细胞中是否恒定表达，以便在研究中可以选择最优的内参做参照。

GAPDH Should Be Cautiously Used as an Internal Reference in Tumor and Aging Tissues

Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is a house-keeping glycolysis gene highly and constantly expressed in almost every tissue. So it is widely used as a relative reference to quantitate proteins, RNA and DNA. But in recent years, GAPDH has been questioned as an internal reference, especially in tumor and aging tissues. Extensive studies have indicated that GAPDH is up-regulated in tumors, and down-regulated in aging muscles. The high expression levels of GAPDH in tumors may be associated with tumor metastasis and proliferation. In this review, we cover the expression of GAPDH in tumor and aging tissues or cells, as well as the possible underlying mechanisms. We aim to provide a blueprint of GAPDH expression in these pathological and physiological processes, facilitating investigators to select a better internal reference in future molecular experiments.