摘要
放射治疗是肿瘤治疗的重要方法之一,据国内外文献统计,70%左右的恶性肿瘤病人需作放射治疗。放射治疗除了有辅助性治疗、姑息性治疗的作用外,还有根治性治疗作用。提高放疗疗效在于增加肿瘤细胞的放射敏感性和减轻正常组织的放射损伤。过氧化物酶体增殖物激活受体(peroxisome proliferators-activated receptors,PPARs)是一类依赖配体活化的转录因子,属于Ⅱ型核激素受体超家族成员。目前已鉴定出具有三个亚型:PPARα,PPARβ/δ和PPARγ,各亚型在不同的组织中分布不同,并发挥不同的生理作用。近些年来,PPAR-γ是国内外研究的热点问题。PPARγ在多种肿瘤组织中均有表达,包括乳腺癌、结肠癌、肝癌、肺癌、胰腺癌等。PPARγ与配体结合后,可通过影响细胞增殖凋亡,血管生成,炎症和转移等过程抑制恶性肿瘤的生长。因此,PPARγ可能通过协同促进肿瘤细胞凋亡,增加肿瘤细胞放射敏感性,减轻周围组织的放射性损伤等作用和放疗联合发挥抗肿瘤作用,PPARγ有望与放疗联合提高治疗比。
Radiation therapy is an important method of cancer treatment. According to a statistics of the literature, 70% of the malignant tumor patients need to receive radiation therapy. In addition to the role of adjuvant treatment and palliative treatment,radiation therapy can also play the role of radical treatment. Increasing the radiosensitivity of tumor cells and reducing the radiation injury of normal tissue can improve the effect of radiation therapy. PPARs （peroxisome proliferators-activated receptors） is a ligand-activated transcription factor that is the member of the class II nuclear hormone receptor superfamily. So far, three isotypes have been identified - PPARα, PPARβ/δ and PPARγ. Each subtype has a different distribution in different tissues and different physiological roles to play. In recent years, research on PPARγ becomes a hot issue both at home and abroad. PPARγ has been shown to be expressed in many cancers ineluding, breast, colon, liver, lung, pancreas,prostae, thyroid, neuroblastoma, etc. An overwhelming number of preclinical-studies demonstrate the efficacy of PPARγ ligands in the control of tumor progression through their affects on various cellular processes. PPARγ can regulate cell proliferation and differentiation, induce apoptosis, mediate inflarmation inhibit angiogenesis and metastasis. A variety of signnaling pathways have been implicated as potential mechanisms of action. However, further investigation is needed at both the scientific and clinical levels. Thus, PPARγ may show synergistic effects with radiation therapy on anti-tumor by promoting apoptosis, increasing the radiosensitivity of tumor cells and reducing the radiation injury of normal tissue. PPARN is expected to improve the therapeutic ratio combined with radiation therapy.
出处
《现代生物医学进展》
CAS
2012年第29期5786-5788,5800,共4页
Progress in Modern Biomedicine
