Figure 7.

OCT depicts the blockade of invasion after sunitinib treatment at the morphologic level. Morphologic characterization of the tumor border by dual-band OCT clearly shows the blockade of invasion after treatment of HaCaT-rasA-5RT3–bearing mice with sunitinib. OCT images (800 and 1220 nm, respectively) of an untreated control (A) and a sunitinib-treated tumor (B). Note the irregular tumor border (indicated by a yellow arrow), typical characteristics of invasion of the untreated control (A), whereas the tumor is separated from the upper dermis by a regular line in the sunitinib-treated tumor (B, indicated by a yellow arrow). (C and D) In situ zymography of MMP activity and counterstaining for collagen IV (red) and DAPI (blue) on corresponding tumor sections demonstrate the irregular tumor border with invasive, infiltrating tumor cell protrusions (indicated by a yellow arrow) in the untreated control tumor (C). In contrast, tumor invasion is blocked after sunitinib treatment, and the tumor is encapsulated and well demarcated from the stroma (D). Note also the partial deposition of collagen IV deposition at the border (indicated by a yellow arrow) and the necrotic area in the center (indicated by a yellow N). (E and F) Representative H&E staining of the different HaCaT-ras A-5RT3 tumors. OCT image size: 2.5 * 1.6 mm. Bar, 200 μm.