Generation of a squamous cell carcinoma mouse model for lineage tracing of BMI1+ cancer stem cells

Abstract

BMI1-expressing cancer stem cells (CSCs) play a key role in the development, progression, therapy resistance, recurrence, and metastasis of head and neck squamous cell carcinoma (HNSCC). Here, we present a chemically-induced HNSCC mouse model, genetically and pathologically similar to human HNSCC. This protocol describes how to use genetic lineage tracing based on the Cre-loxP recombination strategy, which allows us to study the regulation and targeting of BMI1⁺ CSCs in primary tumors and lymph node metastases. For complete details on the use and execution of this protocol, please refer to Chen et al. (2017) and Jia et al. (2020).

Keywords: Cancer; Microscopy; Model Organisms; Stem Cells.

Graphical abstract

Figure 1

Experimental design for tracing Bmi1+ cells in mouse HNSCC induced by 4NQO

Figure 2

Dissection and photographing of mouse HNSCC (A) Dissecting cervical lymph nodes. (B and C) Tumor lesions on the tongue. Scale bar for (A and B), 500 μm; Scale bar for (C), 200 μm.

Figure 3

Histology of normal tongue epithelium and HNSCC (A) normal tongue epithelium (grade 0). (B) epithelial dysplasia confined to tongue epidermis (grade 1). (C) distinct invasion, unclearness of basement membrane, diffuse infiltration into the superficial portion of the muscle layer (grade 2). (D) loss of the basement membrane, extensive invasion into deep muscle layer (grade 3). Scale bars, 200 μm.

Figure 4

Tomato⁺ CSCs in the invasive front of primary and metastatic HNSCC (A) Tomato⁺ CSCs in the invasive front of HNSCC. (B) Metastatic Tomato⁺ CSCs in cervical lymph nodes. Scale bar for (A and B), 50 μm. Figure 4A reprinted with permission from Chen et al., 2017.

Figure 5

Representative PCK staining of non-metastatic and metastatic lymph nodes (A) Non-metastatic lymph nodes with negative PCK staining. (B) Metastatic lymph nodes with positive PCK staining. Scale bars, 200 μm.