[Three-dimensional reconstruction of solid tumors : Morphological evidence for tumor heterogeneity]. / Dreidimensionale Rekonstruktion solider Tumoren : Morphologische Evidenz für Tumorheterogenität.

BACKGROUND: In histopathological routine diagnostics, three-dimensional tissue samples are analyzed histologically and/or immunohistochemically in two-dimensional sectional planes due to the high expenditure of time and the lack of digitization possibilities. AIM: Here, we demonstrate the application of three-dimensional reconstruction to solid tumors and analyze inter-/intratumoral heterogeneity with respect to epithelial-mesenchymal transition (EMT). METHODS: Tissue samples from pancreatic, lung, colorectal, and breast cancers as well as colorectal liver metastases were serially processed in 4µm sections. For individual analyses, alternating stains (cytokeratin AE1/3, zinc finger E­box-binding homeobox 1 (ZEB1), eCadherin) were performed. Subsequently, the tumor cells were analyzed for their morphology (epitheloid amoeboid, mesenchymal) and the expression of ZEB1 and eCadherin. For statistical analysis, all tumor cell aggregates were hierarchically annotated and analyzed. RESULTS: Tumor buds are predominantly associated with the main tumor mass. Furthermore, a shutteling of eCadherin could be observed within tumor cell aggregates smaller than nine cells. ZEB1 is only increasingly expressed in tumor cell groups smaller than five cells. CONCLUSIONS: The initial tumor budding and the subsequent decoupling of the tumor bud from the main tumor mass is most likely a two-part process. However, the EMT is not statistically significantly increased within the tumor bud detached from the main tumor mass. It could be shown that the currently valid and known definition of a tumor bud as a cell cluster of less than or equal to five cells cannot be completely classified in the concept of EMT represented by eCadherin and ZEB1.

Cancer cell invasion and EMT marker expression: a three-dimensional study of the human cancer-host interface.

Cancer cell invasion takes place at the cancer-host interface and is a prerequisite for distant metastasis. The relationships between current biological and clinical concepts such as cell migration modes, tumour budding and epithelial-mesenchymal transition (EMT) remains unclear in several aspects, especially for the 'real' situation in human cancer. We developed a novel method that provides exact three-dimensional (3D) information on both microscopic morphology and gene expression, over a virtually unlimited spatial range, by reconstruction from serial immunostained tissue slices. Quantitative 3D assessment of tumour budding at the cancer-host interface in human pancreatic, colorectal, lung and breast adenocarcinoma suggests collective cell migration as the mechanism of cancer cell invasion, while single cancer cell migration seems to be virtually absent. Budding tumour cells display a shift towards spindle-like as well as a rounded morphology. This is associated with decreased E-cadherin staining intensity and a shift from membranous to cytoplasmic staining, as well as increased nuclear ZEB1 expression.