Department of Pharmaceutical Chemistry, Poznań University of Medical Sciences, 60‑780 Poznań, Poland.
Institute of Molecular Physics, Polish Academy of Sciences, 60-179 Poznań, Poland.
Int J Mol Med. 2017 Aug;40(2):329-336. doi: 10.3892/ijmm.2017.3024. Epub 2017 Jun 14.
In the United States, the annual incidence of bladder cancer is approximately 70,000 new cases, with a mortality rate of approximately 15,000/year. The most common subtype (70%) of bladder cancer is superficial, namely hte non-muscle invasive disease form limited to the urothelium. The rate of progression and recurrence is up to 40 and 70%, respectively. Urothelial cell carcinoma of the bladder is typically treated with transurethral resection. The cancerous cells can float onto the adjacent epithelium, increasing the risk of recurrence. The standard of care is to offer adjuvant intravesical agents to reduce the risk of progression and recurrence. Current intravesical treatments are costly and are associated with special biohazard handling protocols. Patients are treated with intravesical therapy with bacillus Calmetter‑Guerin (BCG) bacterium, or mitomycin C (MMC) following resection, both of which can cause moderate to severe side-effects which are rarely life-threatening. We previously examined the efficacy of epigallocatechin-3-gallate (EGCG) in comparison with MMC to prevent tumor cell implantation/growth in an animal model of superficial bladder cancer. Experiments revile that EGCG is slightly more effective than MMC at decreasing tumor cell implantation and consequent cancer growth in a bladder. This treatment requires the stringent sterile requirement of EGCG. EGCG can be unstable when sterilized at high temperatures. Thus, we evaluated two low temperature sterilization methods, such as ionizing radiation or the filtration method followed by freeze-drying. Both methods ensure the sterility of the sample; however, infrared and HPLC analysis revealed a slightly better stability of irradiated EGCG over the filtration method. The concentration of stable free radicals following irradiation was low, which are unlikely to exert any damaging effects to EGCG. Therefore, we consider that radiation will be the preferred method of EGCG sterilization, and that this may prove useful for the effective use of EGCG in the treatment of bladder cancer.
在美国，膀胱癌的年发病率约为 7 万例，死亡率约为 1.5 万例/年。膀胱癌最常见的亚型（70%）是表浅的，即局限于尿路上皮的非肌肉浸润性疾病形式。进展和复发的比率分别高达 40%和 70%。膀胱尿路上皮癌通常采用经尿道切除术治疗。癌细胞可能会漂浮到相邻的上皮细胞上，增加复发的风险。标准的治疗方法是提供辅助性膀胱内药物治疗，以降低进展和复发的风险。目前的膀胱内治疗方法费用昂贵，且与特殊的生物危害处理方案有关。患者在切除后接受膀胱内治疗，包括卡介苗（BCG）细菌或丝裂霉素 C（MMC）治疗，两者都可能引起中度至重度副作用，但很少危及生命。我们之前曾在一种浅表膀胱癌动物模型中研究了表没食子儿茶素没食子酸酯（EGCG）与 MMC 预防肿瘤细胞种植/生长的疗效。实验结果表明，在降低膀胱肿瘤细胞种植和随后的癌症生长方面，EGCG 比 MMC 略有效。这种治疗方法需要严格的 EGCG 无菌要求。EGCG 在高温下消毒时可能不稳定。因此，我们评估了两种低温消毒方法，如电离辐射或过滤法后冻干。这两种方法都能确保样品的无菌性；然而，红外和 HPLC 分析表明，辐照 EGCG 的稳定性略优于过滤法。辐照后稳定自由基的浓度较低，不太可能对 EGCG 产生任何破坏作用。因此，我们认为辐射将是 EGCG 消毒的首选方法，这可能对有效使用 EGCG 治疗膀胱癌有用。
