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BackgroundAdipose-derived mesenchymal stromal cells (ADSCs) are multipotent stromal cells. The cells secrete a number of cytokines and growth factors and show immunoregulatory and proangiogenic properties. Their properties may be used to repair damaged tissues. The aim of our work is to explain the muscle damage repair mechanism with the utilization of the human adipose-derived mesenchymal stromal cells (hADSCs).MethodsFor the hADSCs isolation, we used the subcutaneous adipose tissue collected during the surgery. The murine hind limb ischemia was used as a model. The unilateral femoral artery ligation was performed on 10–12-week-old male C57BL/6NCrl and NOD SCID mice. The mice received PBS− (controls) or 1 × 106 hADSCs. One, 3, 7, 14 and 21 days after the surgery, we collected the gastrocnemius muscles for the immunohistochemical analysis. The results were analyzed with relevant tests using the Statistica software.ResultsThe retention time of hADSCs in the limb lasted about 14 days. In the mice receiving hADSCs, the improvement in the functionality of the damaged limb occurred faster than in the control mice. More new blood vessels were formed in the limbs of the mice receiving hADSCs than in limbs of the control mice. hADSCs also increased the infiltration of the macrophages with the M2 phenotype (7-AAD−/CD45+/F4/80+/CD206+) into the ischemic limbs. hADSCs introduced into the limb of mice secreted interleukin-6. This cytokine stimulates the emergence of the proangiogenic M2 macrophages, involved, among others, in the repair of a damaged tissue. Both macrophage depletion and IL-6 blockage suppressed the therapeutic effect of hADSCs. In the mice treated with hADSCs and liposomes with clodronate (macrophages depletion), the number of capillaries formed was lower than in the mice treated with hADSCs alone. Administration of hADSCs to the mice that received siltuximab (human IL-6 blocker) did not cause an influx of the M2 macrophages, and the number of capillaries formed was at the level of the control group, as in contrast to the mice that received only the hADSCs.ConclusionsThe proposed mechanism for the repair of the damaged muscle using hADSCs is based on the activity of IL-6. In our opinion, the cytokine, secreted by the hADSCs, stimulates the M2 macrophages responsible for repairing damaged muscle and forming new blood vessels.

Oral cavity cancer is a type of head and neck squamous cell carcinoma (HNSCC) and contributes to significant morbidity and mortality each year. An epigenetic pathway of transcriptional inactivation for many genes has been described in various cancers, including HNSCC. For our study, we selected genes for which silencing caused by hypermethylation can promote cancer development. In 75 primary HNSCC tumours and paired surgical margins, we investigated the methylation status of the p16, APC, MGMT, TIMP3 and CDH1 gene promoters by methylation-specific PCR after bisulphite treatment. The promoter methylation rates of p16, APC, MGMT, TIMP3 and CDH1 in tumours were 58.67%, 49.33%, 58.67%, 50.67%, and 57.33% and 50.67%, 41.33%, 37.33%, 42.67%, and 25.33% in the surgical margin, respectively. Our observations confirm the presence of epigenetic changes not only in the cancer cells, but also in the surrounding mucosa and represent a basis for further analysis to unravel these complicated issues. Appropriate cancer risk assessment based on epigenetic alterations in surgical margins may influence a patient's diagnosis and cure.

Oxidative stress is one of several factors which contribute to the development of colorectal carcinogenesis. The aim of the study was an assessment of the activity of antioxidant enzymes in tumour and corresponding normal distal mucosa in a group of patients with colorectal adenocarcinoma. Samples of tumour and corresponding normal mucosa were obtained during a resection of colorectal cancer from 47 patients aged between 26 and 82 years. The average distance of corresponding normal distal mucosa from the tumour was 4.49 cm. Activities of antioxidant enzymes: superoxide dismutase (SOD), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione S-transferase (GST), and catalase (CAT) were measured in tissue homogenates. The patients were grouped according to the tumour stage (Duke's staging), grading, localization, and size of tumour, as well as age and sex. Statistical analysis was performed. The activity of SOD and GPx was considerably increased, while the activity of GST decreased significantly in tumour as compared with normal mucosa. GR activity in colorectal cancer was evidently higher in tumours of proximal location compared with the distal ones. The distance of corresponding normal distal mucosa from the tumour was analyzed and related to all assayed parameters. A decreased GST activity was observed in corresponding normal mucosa more than 5 cm distant from the tumour in patients with CD Duke's stage. The higher activity of superoxide dismutase and glutathione peroxidase in tumour compared to corresponding normal mucosa could indicate higher oxidative stress in colorectal adenocarcinoma cells.