Peripheral Motor and Sensory Nerve Conduction following Transplantation of Undifferentiated Autologous Adipose Tissue-Derived Stem Cells in a Biodegradable U.S. Food and Drug Administration-Approved Nerve Conduit.

BACKGROUND: Conduits preseeded with either Schwann cells or stem cells differentiated into Schwann cells demonstrated promising results for the outcome of nerve regeneration in nerve defects. METHODS: The concept of this trial combines nerve repair by means of a commercially available nerve guidance conduit and preseeding with autologous, undifferentiated, adipose tissue-derived stem cells. Adipose tissue-derived stem cells were harvested from rats and subsequently seeded onto a U.S. Food and Drug Administration-approved type I collagen conduit. Sciatic nerve gaps 10 mm in length were created, and nerve repair was performed by the transplantation of either conduits preseeded with autologous adipose tissue-derived stem cells or acellular (control group) conduits. After 6 months, the motor and sensory nerve conduction velocity were assessed. Nerves were removed and examined by hematoxylin and eosin, van Gieson, and immunohistochemistry (S100 protein) staining for the quality of axonal regeneration. RESULTS: Nerve gaps treated with adipose tissue-derived stem cells showed superior nerve regeneration, reflected by higher motor and sensory nerve conduction velocity values. The motor and sensory nerve conduction velocity were significantly greater in nerves treated with conduits preseeded with adipose tissue-derived stem cells than in nerves treated with conduits alone (p < 0.05). Increased S100 immunoreactivity was detected for the adipose tissue-derived stem cell group. In this group, axon arrangement inside the conduits was more organized. CONCLUSIONS: Transplantation of adipose tissue-derived stem cells significantly improves motor and sensory nerve conduction velocity in peripheral nerve gaps. Preseeded conduits showed a more organized axon arrangement inside the conduit in comparison with nerve conduits alone. The approach used here could readily be translated into a clinical therapy. CLINCAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Transcription Profile in Sporadic Multiple Symmetric Lipomatosis Reveals Differential Expression at the Level of Adipose Tissue-Derived Stem Cells.

BACKGROUND: The cause of the rare fat distribution disorder multiple symmetric lipomatosis is unknown. Independent reports suggest a higher proliferative activity, hormone resistance, and involvement of mitochondrial function in the disease. METHODS: The authors performed morphologic comparison of affected and unaffected tissues in five unrelated patients and generated adipose-derived stem cell cultures from the tissue samples and characterized them as a possible cellular model of multiple symmetric lipomatosis evolution. The authors investigated proliferative activity and the expression of genes relevant to disease processes. RESULTS: There was no difference in the morphologic appearance and the surface marker profile. Stem cells from lipomatous tissue showed significantly higher proliferative activity. Polymerase chain reaction arrays showed marked changes in genes associated with proliferation, hormonal regulation, and mitochondria. The authors show that multiple symmetric lipomatosis tissue is morphologically and histologically different from regular subcutaneous fat. CONCLUSIONS: This study indicates an involvement of mesenchymal stem cells in the pathogenesis of multiple symmetric lipomatosis and that the evolution of multiple symmetric lipomatosis tissue is a process driven by an inherent defect of the respective cell clone(s). Further molecular genetics and functional analysis will be required to unravel the pathogenetic mechanism underlying the derailment in fat cell metabolism and proliferation. Here, the authors show for the first time that adipose-derived stem cells exhibit many characteristics previously described for native multiple symmetric lipomatosis fat tissue and propose that they are therefore an excellent tool for further functional investigations in multiple symmetric lipomatosis and other disorders of the fat tissue. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, V.

Aberrations of MET are associated with copy number gain of EGFR and loss of PTEN and predict poor outcome in patients with salivary gland cancer.

Hepatocyte growth factor receptor (MET) is a key driver of oncogenic transformation. Copy number gain and amplification of MET positively enhance tumour growth, invasiveness and metastasis in different cancer types. In the present study, 266 carcinomas of the major and minor salivary glands were investigated for genomic MET status by fluorescence in situ hybridization and for protein expression by immunohistochemistry. Results were matched with clinicopathological parameters, long-term survival and the status of epidermal growth factor receptor (EGFR) and phosphatase and tensin homologue (PTEN). Low polysomy (n = 42), high polysomy (n = 27), amplification (n = 2) and deletion (n = 18) were found as aberrations of genomic MET in certain subtypes. MET aberrations were associated with increased patient age (>70 years, p = 0.003), male gender (p = 0.01), increased tumour size (p = 0.002), lymph node metastases (p < 0.001), high-grade malignancy (p < 0.001) and unfavourable overall survival (p < 0.001). Both copy number gain (p < 0.001) and deletion (p = 0.031) of MET correlated with copy number gain of EGFR. Tumours with genomic loss of PTEN (n = 48) concurrently presented aberration of genomic MET (p < 0.001). MET gene status significantly correlated with protein status (p = 0.038). In conclusion, gain but also loss of genomic MET activity correlates with aggressive tumour growth, nodal metastasis and worse overall survival in salivary gland cancer. Moreover, aberrations of MET are associated with EGFR and PTEN signalling and might possess relevance for targeted therapies of salivary gland carcinomas in the future.

The PI3K/AKT/mTOR signalling pathway is active in salivary gland cancer and implies different functions and prognoses depending on cell localisation.

OBJECTIVES: The PI3K/AKT/mTOR signalling axis controls cell proliferation and survival and has achieved major importance as a target for cancer therapy. This investigation evaluated the expression of the major components P-AKT, P-mTOR, PI3K and P-S6rp in salivary gland cancer. MATERIALS AND METHODS: Immunohistochemical expression of P-AKT, P-mTOR, PI3K and P-S6rp was evaluated and correlated to clinicopathological parameters and survival of 272 patients with salivary gland carcinomas. RESULTS AND CONCLUSION: Analysis of all tumours together revealed an increased expression of all components of the pathway in comparison to normal salivary gland control tissue. Nuclear expression of P-AKT was associated with young age, localised tumour stage, absence of lymph node metastases and favourable prognosis. On the contrary, cytoplasmic P-AKT displayed unfavourable tumour characteristics like high-grade malignancy, and worse overall survival. In comparison to cytoplasmic/membrane mTOR expression, nuclear P-mTOR was associated with absence of lymph node metastases and higher survival rates. PI3K and P-S6rp were exclusively found in the cytoplasm. Expression of P-S6rp was correlated to increased age, advanced tumour size and lymph node metastases. In all tumours together, nuclear P-AKT positively correlated with nuclear P-mTOR, whereas P-S6rp was associated with expression of PI3K and cytoplasmic P-AKT. In acinic cell carcinoma, cytoplasmic expression of P-AKT, P-mTOR, PI3K and P-S6rp was positively associated with each other. In conclusion, PI3K/AKT/mTOR signalling is active in salivary gland cancer and might function as a target for personalised therapy. P-AKT and P-mTOR possess distinct molecular functions with impact on prognosis depending on their cellular localisation.

EGFR, HER2, survivin, and loss of pSTAT3 characterize high-grade malignancy in salivary gland cancer with impact on prognosis.

Increased gene copy number (high polysomy or amplification) of EGFR and HER2 has evolved as a predictor for response to targeted therapy. STAT3 and the apoptosis inhibitor survivin represent distinct oncogenes in various human neoplasms. The purpose of this study was to evaluate protein and gene status of these biomarkers by immunohistochemistry and dual color fluorescence in situ hybridization on tissue microarrays of 286 salivary gland carcinomas in the context of clinical and histopathologic characteristics. Diverse tumor types showed overexpression and increased gene copy number of EGFR and HER2. Amplification of HER2 was found in 35.5% of salivary duct carcinomas. Protein overexpression was strongly associated with high gene copy number for both EGFR and HER2 (P < .001). Overexpression and increased gene copy number of EGFR and HER2 were correlated to high-grade malignancy (P < .001) and unfavorable prognosis (P < .001). Strong nuclear staining of survivin was found in 18.9% of tumors and was associated with high-grade malignancy (P < .001), overexpression, and high gene copy number of EGFR and HER2 (P ≤ .05) as well as unfavorable prognosis (P < .001). Overexpression of nuclear pSTAT3 was found in 28.3% of tumors and correlated with well tumor differentiation (P < .001) and favorable prognosis (P = .001). Loss or weak expression of pSTAT3 was inversely associated with overexpression of survivin (P < .001) as well as overexpression and high gene copy number of EGFR and HER2 (P < .05). Overall, overexpression and increased gene copy number of EGFR and HER2 characterize high-grade malignancy with unfavorable prognosis in salivary gland cancer. Nuclear survivin typifies aggressive tumors with worse prognosis, whereas nuclear pSTAT3 might play a role as a tumor suppressor in absence of EGFR, HER2, and survivin.