Three-dimensional analysis of tumor vessels in transplanted VX2 tongue cancer.

Abstract

The aim of the present study was to clarify the morphological changes and location of the preexisting and neovasculatures, associated with the growth of tumor, by three-dimensional reconstruction of the distribution of arteries changing with the lapse of days after transplantation of the VX2 cancer into the rabbit tongue.

Serial sections of the specimens injected with India ink were prepared 3,7 and 14 days after transplant. The sections were observed with a light microscopy and photographed. The micrographs were inputted into a computer as image data. Tumor vessels were then reconstructed three-dimensionally using image analysis software VoxelView. The morphology and number of furcations of tumor vessels were examined. The diameter of these vessels were also measured.

In the specimens after 3 days, tumor growth inside the vertical muscle of the tongue, dilatation and tortuousness of the preexisting capillaries adjacent to the periphery of the tumor were observed. In the specimens after 7 days, cancer nests formed by the tumor and capillaries invading the stroma were observed. These capillaries took a basket-mesh-like running course different from the capillary network in stroma surrounding the tumor, which clearly indicated that they were neovasculatures. In the specimens after 14 days, dilatations of the dorsal lingual branches and precapillary arterioles, the reduced number of furcations and precapillary arterioles inside the tumor nest were observed, accompanied by the neovasculatures. In addition, dilatation and tortuousness of the preexisting capillaries observed at 3 and 7 days after tumor transplantation were identified in the surrounding tumor stroma in association with the tumor growth.

It is suggested that the changes of tumor vessels induced by transplanted VX2 cancer into the tongue will pass through three phases: dilatation, tortuousness of the preexisting vessels and angiogenesis in order.