mTOR Pathway Substrates Present High Activation in Vascular Malformations and Significantly Decrease with Age.

BACKGROUND: Vascular anomalies often result in aesthetic flaws, pain, and impair the quality of life. They require challenging treatments that frequently do not provide the desired results. The mammalian target of rapamycin (mTOR) is directly involved in the development of these malformations. However, the exact mechanism behind mTOR dysregulation has not been unambiguously defined. The purpose of this study is to investigate the activation of selected substrates of mTOR to partially assess its involvement in the disease process. METHODS: We analyzed tissue samples collected from patients with vascular anomalies treated in our department. We included patients with histopathological diagnoses of lymphatic, venous, capillary malformations, mixed lesions, and a control group of healthy skin samples. We stained the samples using H and E and immunohistochemistry. We used primary antibodies against p70 S6 Kinase, 4EBP1, and p-4EBP1. We graded their color reactions. The statistical analyses were performed using the FactoMineR and factoextra R v.4.1 packages. p-values < 0.05 were considered statistically significant. RESULTS: The analysis of 82 patients showed that healthy tissue vessels expressed lower levels of tested mTOR pathway substrates compared to high activation in vascular malformations. Elevated substrate expression in a comparison between sexes revealed higher P-4EBP1 expression in the female malformation group. We observed a decrease in mTOR substrate expression with age. CONCLUSION: The higher expression of mTOR substrates in vascular malformations compared to healthy tissue confirms their involvement in abnormal vascular development. Age-related changes in mTOR substrate expression highlight the need for timely intervention. Our study contributes to the understanding of the mTOR signaling pathway in vascular malformations and highlights its potential as a therapeutic target, contributing to personalized medicine.

Ovarian carcinoma in children with constitutional mutation of SMARCA4: single-family report and literature review.

Ovarian carcinoma is an extremely rare malignancy in children, often developing on the underlying inherited background. Female carriers of pathogenic germline mutations of SMARCA4 are at risk of an aggressive type of undifferentiated ovarian cancer called small cell carcinoma of the ovary, hypercalcemic type (SCCOHT). Regardless of age of the patient, stage of the disease, and oncological treatment, the prognosis for SCCOHT is poor. Therefore, early intervention with risk-reducing surgeries is recommended for these patients. In this study, we report genetic testing of a family with two children carrying pathogenic germline mutations of SMARCA4 and summarize the course of SCCOHT in all pediatric patients reported in the literature with constitutional defects identified within the SMARCA4 locus.

Impact of mTOR expression on clinical outcome in paediatric patients with B-cell acute lymphoblastic leukaemia - preliminary report.

AIM OF THE STUDY: To characterise expression of mTOR (mammalian target of rapamycin) in childhood B-cell acute lymphoblastic leukaemia (ALL), and to evaluate a possible link between mTOR and clinical characteristics. MATERIAL AND METHODS: The examined group consisted of 21 consecutive patients, aged 1-18 years, diagnosed with B-cell ALL in 2010, and 10 relapsed B-cell ALL patients diagnosed for the first time between 2009 and 2011, who developed relapse before 2014. All subjects were treated in the Department of Paediatric Haematology and Oncology of the Medical University of Warsaw according to the ALL-IC BFM 2002 Protocol. We evaluated mTOR and phospho-mTOR expression by immunohistochemistry using rabbit monoclonal antibodies. RESULTS: mTOR expression was found to be significantly associated with the risk of relapse and was more frequent in ALL recurrence. No significant relationship was detected between mTOR expression and other features of high-risk disease in paediatric ALL. CONCLUSIONS: mTOR activity could be considered a high-risk feature in paediatric B-cell ALL. Expression of mTOR kinase is observed remarkably more frequently in disease recurrence than at first diagnosis, indicating higher proliferative and survival potential of leukaemic cells in relapse. Routine analysis of mTOR activity could be performed to select patients that may potentially benefit from mTOR inhibitors (MTI) treatment.

Estimation of diagnostic value of chosen markers of neural differentiation in neuroblastoma group of tumors and pPNETs.

Neuroblastoma and peripheral PNETs both are typical examples of wide group of small round blue cell tumors of childhood. Matured neuroblastoma show typical clinical presentation and easy to interpret microscopic picture. Unfortunately in everyday practice much commonly appeared less differentiated neuroblastomas with difficult to predict clinical behavior and impossible to diagnose in routine stain histologic view. Peripheral PNETs are found as morphologically similar entities to some neuroblastoma subtypes but they are treated as separate CD99 positive group of tumors with different biology and clinical behavior. The aim of our study was to estimate the usefulness of neural markers expression (Neuroblastoma Marker, neurospecyfic enolase and neurofilaments) in routine separation between neuroblastoma tumors and pPNETs and between neuroblastoma subtypes according to currently used classification of those entities. We investigated 63 tumor tissue samples and found differences in expression of investigated markers between both neuroblastoma subgroups and neuroblastoma group of tumors and pPNETs.

Analysis of P53 and P21WAF1 proteins expression in follicular thyroid tumors.

The expression of P53 and P21WAF1 proteins was analyzed immunohistochemically in archival material derived from 12 cases of follicular thyroid carcinoma, 57 cases of follicular adenoma and 17 cases of nodular goiter. In the follicular carcinoma group 6 out of 12 cases (50%) were positive for P53 protein and 4 out of 12 cases (33.3%) were positive for P21WAF1 protein. In the follicular adenoma group, 18 out of 57 cases (31.6%) were positive for P53 and 16 out of 57 cases (28.1%) were positive for P21WAF1 protein. No positive cases of P53 or P21WAF1 proteins presence were found in the nodular goiter group. Positive correlation between the expression of P53 and P21WAF1 proteins was found for follicular carcinoma and adenoma groups (p = 0.034 and p = 0.002, respectively). The obtained results demonstrate that simultaneous immunohistochemical detection of P53 and P21WAF1 proteins expression may be useful in determining functional status of P53 protein, helping to interpret expression of P53 protein in thyroid follicular carcinoma cells.

Analysis of P161NK4A protein expression in follicular thyroid tumors.

PI6INK4A (P16) protein expression was analyzed immunohistochemically in archival material derived from 12 cases of follicular thyroid carcinoma, 57 cases of follicular adenoma and 17 cases of nodular goiter. Among follicular carcinomas, 11 out of 12 examined cases (91.7%) were positive for P161NK4A protein. Among follicular adenomas the percentage of immunopositivity was 76.5% (45/57) and among nodular goiter cases it was 19.3% (13/17). Overexpression of P16INK4A protein was found in 66.7% (8/12) of follicular carcinomas and in 19.3% (11/57) of follicular adenomas; the values of this parameter were statistically significantly higher in the follicular carcinoma group (p < 0.005). No P16INK4A protein overexpression was noted in nodular goiter cells. High immunohistochemically-detected expression of P16INK4A protein in follicular thyroid carcinoma cells suggests that the altered expression pattern of P16INK4A protein may disturb the regulatory mechanisms of thyreocyte cell cycle and plays a significant role in the formation of benign neoplasms and their malignant counterparts derived from follicular thyroid cell.

Analysis of nm23-H1 protein immunoreactivity in follicular thyroid tumors.

Immunohistochemical analysis employing a monoclonal antibody nm23-H1 (the antibody against nm-23 protein) was performed on archival material, consisting of 12 cases of follicular thyroid carcinoma (FTC), 57 cases of follicular thyroid adenoma (FTA) and 17 cases of nodular goiter (NG). Both cytoplasmic and nuclear immunoreactions for nm-23H1 were observed in cells of FTCs, FTAs and NGs. In oxyphilic adenomas cytoplasmic staining was observed. Eleven (91.7%) cases of FTC, 55 (98.2%) cases of FTA and 14 (82.4%) cases of NG were found to be positive for nm23-H1 protein. There were no statistically significant differences in the mean percentage values of immunopositive cells between carcinomas and adenomas. A significant increase in the number of cases with high percentage (more than 50) of positive cells was found in both carcinomas (FTCs) and adenomas (FTAs)--mainly microfollicular ones, in comparison with nodular goiter. It can be concluded that highly positive immunoreaction for the nm23-H1 protein in the cells of carcinomas (FTCs) and microfollicular adenomas indicates for a high proliferation rate of these tumors.