Fig. 1

Epithelial tumor morphological characteristics of TJ-GBC2 cell line. a Morphology of TJ-GBC2 cell lines (at the passage 35–50) under a light microscopy (a1 × 100, a2 × 200). Cells grew mainly in clusters of polygonal cells, partially fusiform, spindly or irregular shape as an adherent monolayer sheet with characteristic epithelial cell morphology, in addition to big nucleoplasm ratio and multiple nucleoli. b Karyomegaly, dicaryon, clear cellular organelle structures such as ribosomes, mitochondria, prosperous endoplasmic reticulum, Golgi apparatus and secretory granules in cytoplasm, and lots of microvilli outside the network and cell connection were clearly observed under a transmission electron microscopy (TEM; b1–b3, × 10,000). c The divided cell and its surface full of densely filamentous microvilli and lamellar prominences were clearly visualized under a scanning electron microscopy (SEM; c1 × 2500, c2 × 7500, c3 × 4500). d The xenograft of TJ-GBC2 cells in nude mice in vivo presented typical GBC features in nest-streak like arrangement with atypical hyperplasia, caryokinesis and poor differentiation e.g. most of mucous epidermoid carcinoma differentiation, which were consistent with primary tumor of GBC