Mesenchymal stem cells may differentiate into hepatocyte-like cells in vitro and in vivo. Therefore, they are considered a novel cell resource for the treatment of various liver diseases. Here, the aim was to demonstrate that mesenchymal stem cells may adopt both perivenous and periportal hepatocyte-specific functions in vitro and in vivo.

Adipose tissue-derived mesenchymal stem cells were isolated from immunodeficient C57BL/6 (B6.129S6-Rag2(tm1Fwa) Prf1(tm1Clrk) ) mice and differentiated into the hepatocytic phenotype by applying a simple protocol. Their physiological and metabolic functions were analysed in vitro and after hepatic transplantation in vivo.

Mesenchymal stem cells changed their morphology from a fibroblastoid into shapes of osteocytes, chondrocytes, adipocytes and hepatocytes. Typical for mesenchymal stem cells, hematopoietic marker genes were not expressed. CD90, which is not expressed on mature hepatocytes, decreased significantly after hepatocytic differentiation. Markers indicative for liver development like hepatic nuclear factor 4 alpha, or for perivenous hepatocyte specification like cytochrome P450 subtype 3a11, and CD26 were significantly elevated. Periportal hepatocyte-specific markers like carbamoylphosphate synthetase 1, the entry enzyme of the urea cycle, were up-regulated. Consequently, cytochrome P450 enzyme activity and urea synthesis increased significantly to values comparable to cultured primary hepatocytes. Both perivenous and periportal qualities were preserved after hepatic transplantation and integration into the host parenchyma.

Adult mesenchymal stem cells from adipose tissue differentiated into hepatocyte-like cells featuring both periportal and perivenous functions. Hence, they are promising candidates for the treatment of region-specific liver cell damage and may support organ regeneration in acute and chronic liver diseases.

Liver metastases are the major cause of cancer-related death in colorectal cancer patients with a tendency to recur in over 50 % of the cases even after curatively intended surgery. Prognosis after liver resection, however, can neither be based on macroscopic or light microscopic evaluation of the metastases nor on clinical data alone. This is a pilot study in order to determine a potential influence of chromosomal aberrations on overall survival and relapse rate after curative liver resection.

Twenty randomly selected cases (10 patients with a survival of more and 10 patients with a survival of less than 5 years after resection) were studied by array comparative genomic hybridization.

The distributions concerning age, gender, stage and grading of primary tumor, percentage of patients with chemotherapy, number and distribution of the liver metastases, Nordlinger and Fong scores showed no differences between long- and short-term survivors and no correlation to any chromosomal aberration. However, the relapse rate of patients with (partial) monosomy 4 was lower and the long-time survival better than in the other patients.

Loss of chromosome 4 in colorectal liver metastases seems not only to be associated with the progression of the primary tumor as reported in the literature, but also with the long-term survival and the cumulative relapse rate after complete resection of colorectal liver metastases.

Fluorescence in situ hybridization (FISH) is increasingly gaining importance in clinical diagnostics settings. Due to the ability of the technique to detect chromosomal abnormalities in samples with low cellularity or containing a mixed population of cells even at a single-cell level, it has become more popular in cancer research and diagnosis. Here, we describe the FISH technique for detection of PAX8-PPARγ translocation in follicular thyroid neoplasms, and the optimal protocol for the detection of this fusion gene using in archival formalin-fixed paraffin-embedded (FFPE) thyroid tissue sections.

Fluorescence in situ hybridization (FISH) assays are indispensable in diagnostics and research. Routine application of this so-called molecular cytogenetic technique on human chromosomes started in 1986. Since then, a huge variety of different approaches for chromosomal differentiation based on FISH has been described. It was established to characterize marker chromosomes identified in conventional banding analysis as well as cryptic rearrangements not resolved by standard cytogenetics.

Even though molecular cytogenetics, like banding cytogenetics for almost 40 years, is often called dead now, it offers unique possibilities of single cell analysis. Thus, a review is presented here on the available diagnostic-relevant FISH methods and probe sets applied in routine pre- and postnatal clinical as well as tumor cytogenetics.

Molecular cytogenetics is a fast, straightforward and reliable tool that is indispensable in cytogenetic diagnostics. It is and will continue to be of high clinical impact in diagnostics, especially in the overwhelming majority of routine cytogenetic laboratories that cannot afford and do not need high-throughput chip-based platforms for their daily work.