Heparanase expression, degradation of basement membrane and low degree of infiltration by immunocytes correlate with invasion and progression of human gastric cancer

Figure 2 Transmission electron microscopy micrographs of the human gastric cancer tissues. (A)-(D) showing the early stage cancer tissues (Arrows indicate basement membrane). A: The continuous basement membrane which consisted of the electron-dense outer layer and the electron-lucent inner layer was observed. The numerous tumor infiltrating lymphocytes (L) were located in one side of the basement membrane (× 2500); B and C: The intact basement membrane was found on the margin of cancer nests. The tumor infiltrating lymphocytes (L) appeared around the cancer cell (Ca) (B × 4000; C × 3000); D: The cancer cell (Ca) was surrounded by the tumor infiltrating lymphocytes (L), and the basement membrane is clearly visualized (× 2500); (E)-(H) showing the late stage cancer tissues. E: The relationships were displayed between cancer cells (Ca) or tumor infiltrating lymphocytes (L) and tumor infiltrating dendritic cells (D). Note the tumor with absent basement membrane (× 4000); F: A higher magnification of E exhibited the contact relationship between the cancer cell (Ca) and tumor infiltrating dendritic cell (D) (×20 000). G: The tumor infiltrating dendritic cell (D) was surrounded by several tumor infiltrating lymphocytes (L), and formed the dendritic cell-lymphocyte cluster (× 5000); H: The tumor infiltrating lymphocyte (L) appeared near the cancer cell (Ca), and the discontinuous or defective basement membrane of cancer nest can also be seen (double arrow) (× 5000).