Involvement of the HPA axis in the relationship between the psychological stress and cancer development.

癌症是日本人死亡的主要原因。人们普遍认为，心理应激是影响癌症发生的重要因素之一，但其因果关系的分子机制仍然知之甚少。在这项研究中，我们研究了在心理应激中起重要作用的HPA轴是否会影响肿瘤细胞的生长。结果，皮质醇的血清水平在心理应激时升高，显著促进了包括人胃癌、结肠癌、子宫癌、乳腺癌和肺癌在内的肿瘤细胞的生长，而环境条件如缺氧也影响了肿瘤的生长速率。本研究提示，心理应激可能通过HPA通路导致癌症的发生和发展。

Cancers are the leading cause of death in Japan. It is widely considered that psychological stress is one of the important factors that affect carcinogenesis, but the molecular mechanisms underlying the causal relationship remain poorly understood. In this study, we examined whether the HPA axis that plays important roles in psychological stress may have impact on tumor cell growth. As results, cortisol, the serum level of which is elevated upon psychological stress, significantly promoted the growth of tumor cells including human stomach, colon, uterus, mammary, and lung cancers, while environmental conditions such as hypoxia also affected the growth rates of the tumors. The present study suggests that the psychological stress may cause cancer development and progression through the HPA pathway.