Department of Pathology, Virginia Commonwealth University School of Medicine.
Department of Pathology, Virginia Commonwealth University School of Medicine; Massey Cancer Center, Virginia Commonwealth University School of Medicine;
J Vis Exp. 2022 Jun 23(184). doi: 10.3791/64002.
Metastasis remains the primary cause of cancer-related death. The succession of events that characterize the metastatic cascade presents multiple opportunities for therapeutic intervention, and the ability to accurately model them in mice is critical to evaluate their effects. Here, a step-by-step protocol is presented for the establishment of orthotopic primary breast tumors and the subsequent monitoring of the establishment and growth of metastatic lesions in the lung using in vivo bioluminescence imaging. This methodology allows for the evaluation of treatment or its biological effects along the entire range of metastatic development, from primary tumor escape to outgrowth in the lungs. Breast orthotopic tumors are generated in mice via injection of a luciferase-labeled cell suspension in the 4th mammary gland. Tumors are allowed to grow and disseminate for a specific amount of time and are then surgically resected. Upon resection, spontaneous lung metastasis is detected, and the growth over time is monitored using in vivo bioluminescence imaging. At the desired experimental endpoint, lung tissue can be collected for downstream analysis. The treatment of established, clinically evident metastasis is critical to improve outcomes for stage IV cancer patients, and it can be evaluated through tail vein models of experimental lung metastasis. However, metastatic dissemination occurs early in breast cancer, and many patients have latent, subclinical disseminated disease after surgery. Utilization of spontaneous models such as this one provides the opportunity to study the whole spectrum of the disease, especially the systemic effects driven by treatment of the primary tumor such as pre-metastatic niche priming, and evaluate treatments on dormant and subclinical disease after surgery.
转移仍然是癌症相关死亡的主要原因。转移级联所具有的特征事件序列为治疗干预提供了多个机会，并且在小鼠中准确模拟它们的能力对于评估它们的效果至关重要。这里提供了一个逐步的方案，用于建立原位原发性乳腺肿瘤，并随后使用体内生物发光成像监测肺中转移性病变的建立和生长。该方法允许评估治疗或其生物学效应沿着整个转移发展范围，从原发性肿瘤逃逸到肺部生长。通过在第 4 个乳腺中注射荧光素酶标记的细胞悬浮液在小鼠中产生乳腺原位肿瘤。允许肿瘤生长和扩散特定的时间量，然后进行手术切除。切除后，自发的肺转移被检测到，并使用体内生物发光成像监测随时间的生长。在所需的实验终点，可收集肺组织进行下游分析。对已建立的、临床明显的转移的治疗对于改善 IV 期癌症患者的预后至关重要，并且可以通过实验性肺转移的尾静脉模型进行评估。然而，转移性播散在乳腺癌早期发生，并且许多患者在手术后具有潜在的、亚临床播散性疾病。利用这种自发性模型提供了研究整个疾病谱的机会，特别是由原发性肿瘤治疗驱动的全身性效应，例如前转移龛位启动，并评估手术后休眠和亚临床疾病的治疗。
