Chiang Kun-Chun, Chen Tai C
Department of Surgery, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan 333, Taiwan, China.
World J Gastroenterol. 2009 Jul 21;15(27):3349-54. doi: 10.3748/wjg.15.3349.
Pancreatic cancer is ranked fifth among cancer-related deaths worldwide with a 5-year survival rate of less than 5%. Currently, surgery is the only effective therapy. However, most patients are diagnosed in the late stage and are not suitable for receiving curative surgery. Moreover, pancreatic cancer doesn't respond well to traditional chemotherapy and radiotherapy, leaving little effective treatment for advanced pancreatic cancer cases. 1alpha,25-dihydroxyvitamin D(3) [1alpha,25(OH)(2)D(3)], the biologically active form of vitamin D(3), was originally identified during studies of calcium and bone metabolism, though it is now recognized that it exerts biological effects in almost every tissue in the body. Abundant evidence has shown that 1alpha,25(OH)(2)D(3) has antiproliferative, apoptotic, pro-differentiation and antiangiogensis effects in many types of cancer cells in vivo and in vitro, including breast, prostate, and colon. Similarly, the antitumor growth effect of 1alpha,25(OH)(2)D(3) on pancreatic cells has been demonstrated. The clinical use of 1alpha,25(OH)(2)D(3) is impeded by the lethal side effects of hypercalcemia and hypercalciuria. Therefore, 1alpha,25(OH)(2)D(3) analogs, which are either equipotent or more potent than 1alpha,25(OH)(2)D(3) in inhibiting tumor cell growth but with fewer hypercalcemic and hypercalciuric side effects, have been developed for the treatment of different cancers. Recently, a pre-clinical study demonstrated that a less calcemic analog of 1alpha,25(OH)(2)D(3), 19-nor-1alpha,25(OH)(2)D(2) (Paricalcitol), is effective in inhibiting tumor growth in vitro and in vivo, via upregulation of p21 and p27 tumor suppressor genes. Studies on the anti-tumor effects of a more potent analog of Paricalcitol are underway. 1alpha,25(OH)(2)D(3) and its analogs are potentially attractive novel therapies for pancreatic cancer.
胰腺癌在全球癌症相关死亡中位列第五,5年生存率低于5%。目前,手术是唯一有效的治疗方法。然而,大多数患者在晚期才被诊断出来,不适合接受根治性手术。此外,胰腺癌对传统化疗和放疗反应不佳,晚期胰腺癌病例的有效治疗手段很少。1α,25-二羟基维生素D(3)[1α,25(OH)₂D(3)]是维生素D(3)的生物活性形式,最初是在钙和骨代谢研究中被发现的,不过现在人们认识到它在人体几乎每个组织中都发挥着生物学作用。大量证据表明,1α,25(OH)₂D(3)在体内外对多种癌细胞,包括乳腺癌、前列腺癌和结肠癌,具有抗增殖、促凋亡、促分化和抗血管生成作用。同样,1α,25(OH)₂D(3)对胰腺细胞的抗肿瘤生长作用也已得到证实。1α,25(OH)₂D(3)的临床应用因高钙血症和高钙尿症的致命副作用而受到阻碍。因此,已开发出1α,25(OH)₂D(3)类似物,它们在抑制肿瘤细胞生长方面与1α,25(OH)₂D(3)等效或更有效,但高钙血症和高钙尿症副作用较少,用于治疗不同癌症。最近,一项临床前研究表明,一种钙血症较轻的1α,25(OH)₂D(3)类似物,19-去甲-1α,25(OH)₂D(2)(帕立骨化醇),通过上调p21和p27肿瘤抑制基因,在体外和体内均能有效抑制肿瘤生长。关于一种更有效的帕立骨化醇类似物的抗肿瘤作用的研究正在进行中。1α,25(OH)₂D(3)及其类似物可能是胰腺癌有吸引力的新型治疗方法。