Yang Jian, Zhao Teng, Nian Baoning, Yang Chao, Zhu Yu, Xu Yongfu, Xu Xiaoya, Chen Sheng, Li Zhikuan, Zhang Wei, Zhang Dadong, Lu Kai, Zhang Fabiao
Department of Hepatobiliary Surgery, Taizhou Hospital of Zhejiang Province, Wenzhou Medical University, Taizhou, China.
Department of Biliary Surgery, Third Affiliated Hospital of Naval Medical University (Eastern Hepatobiliary Surgery Hospital), Shanghai, China.
Transl Cancer Res. 2024 Oct 31;13(10):5328-5338. doi: 10.21037/tcr-24-843. Epub 2024 Oct 29.
Patients with biliary tract cancer (BTC) often have dismal outcomes due to the poor performance of traditional methods for early diagnosis. Recently, bile cell-free DNA (cfDNA) has been reported as a potential liquid biopsy material for BTC diagnosis. However, bile is a complex alkaline aqueous medium, and the proper storage conditions for bile remain to be explored. The aim of this study is to explore the effects of storing bile under various conditions on the stability of bile cfDNA and to determine the optimal conditions, thereby establishing a foundation for the subsequent application of bile cfDNA in liquid biopsy for early diagnostic and prognosis monitoring of patients with malignant BTC.
We evaluated the storage temperature and storage time for the preservation of bile samples. Bile samples were collected in cfDNA tubes with protectant covered inside or regular tubes without, and the stability of bile cfDNA was analyzed during 10 days at room temperature (RT) or after 2 months of storage at low temperatures.
Bile cfDNA remained stable for bile samples being collected with cfDNA tubes and stored for 10 days at RT, while degraded with time for the case with regular tubes. When bile samples were collected with cfDNA tubes and stored for 2 months at 4 ℃, bile cfDNA remained stable, however, if collected with regular tubes, bile cfDNA exhibited a slight loss of integrity. No significant difference was observed for 2 months storage at -20 or -80 ℃.
Our findings suggested that for bile cfDNA research, bile samples should be collected with cfDNA tubes and it can be transported for short-term shipment at RT, and could be stored at 4 ℃ with cfDNA tubes, or frozen at -20 ℃ with regular tubes.
由于传统早期诊断方法效果不佳，胆道癌（BTC）患者的预后往往很差。最近，胆汁游离DNA（cfDNA）已被报道为一种用于BTC诊断的潜在液体活检材料。然而，胆汁是一种复杂的碱性水性介质，胆汁的合适储存条件仍有待探索。本研究的目的是探讨在各种条件下储存胆汁对胆汁cfDNA稳定性的影响，并确定最佳条件，从而为胆汁cfDNA随后在液体活检中用于BTC恶性肿瘤患者的早期诊断和预后监测奠定基础。
我们评估了保存胆汁样本的储存温度和储存时间。胆汁样本收集在内部覆盖有保护剂的cfDNA管或无保护剂的普通管中，并在室温（RT）下10天内或在低温下储存2个月后分析胆汁cfDNA的稳定性。
对于用cfDNA管收集并在室温下储存10天的胆汁样本，胆汁cfDNA保持稳定，而对于普通管的情况，其随时间降解。当胆汁样本用cfDNA管收集并在4℃下储存2个月时，胆汁cfDNA保持稳定，然而，如果用普通管收集，胆汁cfDNA的完整性略有损失。在-20℃或-80℃下储存2个月未观察到显著差异。
我们的研究结果表明，对于胆汁cfDNA研究，应使用cfDNA管收集胆汁样本，它可以在室温下短期运输，并且可以用cfDNA管在4℃下储存，或用普通管在-20℃下冷冻。
