Evaluating survivin gene expressiion changes in adult mice following sciatic nerve injury

Because of the necessity of more effective treatments for the nervous system injuries and considering the role of survivin in cellular proliferation and apoptotic cell death, we have monitored survivin gene expression changes during the course of regeneration in injured sciatic nerves and also L4-L6 segments of spinal cord. We used adult male NMRI mice as a model. After anesthetizing the animals, the right sciatic nerve was transected and at the indicated times [3, 6, 12, 24, 48, 96 and 144 hours] the animals were sacrificed and both distal and proximal segments of the transected sciatic nerve, intact left sciatic nerve and L4-L6 segments of spinal cord were dissected. The total RNA was extracted from each sampled and semi-quantitative RT-PCR with specific primers for survivin and also beta2-microglobulin genes, as an internal control, was performed. To determine cellular distribution of survivin protein, 6 days [144 hours] after the axotomy, survivin protein expression was evaluated using immunohistochemistry technique. Our results demonstrated the expression of both survivin140 and survivin40 in distal and proximal segments of sciatic nerve with different intensity, where the expression of survivin140 was higher than survivin40. In spinal cord segments, only survivin140 expression was detected. In immunohistochemistry analysis of spinal cord segments, both the nuclear and cytoplasmic distribution of survivin protein was observed. In contrast, survivin protein has not been detected in either distal or proximal segments of sciatic nerve. Our data suggest that survivin is differentially expressed and spliced during the course of regeneration in damaged nerve and spinal cord. It seems that manipulation of expression and/or splicing of survivin could potentially affect the process of regeneration in nerve and/or spinal cord injuries

Evaluating the expression of survivin gene as a specific tumor marker for prognosis of bladder cancer

Inhibition of apoptosis may favor the onset and progression of cancer. Survivin is an inhibitor of apoptosis that has been considered as a potential marker for diagnostic and/or prognostic of bladder cancer. The survivin protein regulates both cell division and cell death and its overexpressed in the vast majority of human cancers. In this study, the expression pattern and potential prognostic value of survivin was assessed in Fomalin-Fixed Paraffin-Embedded [FFPE] samples of bladder tumor. FFPE samples, from patients with a well-known five-year survival record, were assessed by semi-quantitative RT-PCR technique. 51 samples from 30 patients were analyzed on the basis of Survivin expression. Tissue distribution and subcellular localization of survivin protein in tumor tissues was also examined by immunohistochemistry [IHC]. The expression of survivin in 66.6% of the samples, with an increase of expression in higher grades of tumor. Furthermore, survivin was overexpressed in 2[nd] and 3[rd] recurrences of the same patients. Also, with the increased malignancy and accordingly increase expression of surviving, the overall 5-year survival rate of patients was significantly declined [P=0.036]. IHC results also localized a nuclear localization for Survivin protein in tumor tissues. In coclusion, we were able to detect the expression of survivin in FFPE samples of bladder tissues, at the level of mRNA and protein and find a correlation between the level of Survivin expression and the degree of malignancy of the tumors. Our findings introduce Survivin as a suitable prognostic marker for predicting the bladder tumors