Telomerase inhibition regulates EMT mechanism in breast cancer stem cells

Avci, Cigir Biray/0000-0001-8251-4520; Gunduz, Cumhur/0000-0002-6593-3237; Kusoglu, Alican/0000-0002-7394-2416WOS: 000566791200008PubMed: 32738420Backround: CSCs having the common features of high telomerase activity and high migration and invasion capabilities play a vital role as the initiators of metastasis. Small molecule BIBR1532 has been shown to target cancer cells by inhibiting telomerase. Recent studies have suggested that telomerase activity is associated with epithelial mesenchymal transition (EMT). EMT program, which causes epithelial cells to acquire a mesenchymal morphology, is known to play a significant role in cancer metastasis. Methods: the hypothesis of our study was that suppression of telomerase in breast cancer and cancer stem cells would interrupt EMT mechanism. Cytotoxicity of BIBR1532 was evaluated using WST-1 assay in all cell lines and the effects of BIBR1532 on apoptosis were investigated with Annexin V. Migration rate of the cells was examined by wound healing assay and sphere forming capacities were observed by hanging drop test. Finally, the expression of 84 EMT-related genes was analyzed by real-time qPCR. Results: the IC50 values for the MDA-MB-231 and breast epithelial stem cells of BIBR1532 were analyzed as 18.04 and 38.71 mu l at 72 h, respectively. Interestingly, apoptosis was only induced in stem cells. in hanging drop test, sphere areas were reduced in stem cells treated with BIBR1532. in wound healing assay, BIBR1532 decreased the migration rate of stem cells. Together with this, expression of EMT-related genes were regulated in stem cells towards a epithelial phenotype. Conclusion: Our obtained results indicated that telomerase inhibition affects the EMT mechanism. the targeted elimination of breast cancer stem cells by a telomerase inhibitor in cancer treatment may limit the mobility and stemness of cancer cells interrupting the EMT mechanism, thus may prevent metastasis.Research Foundation of Ege University Medical SchoolOur study is supported by Research Foundation of Ege University Medical School

Effects of telomerase inhibitor on epigenetic chromatin modification enzymes in malignancies

WOS: 000450130500019PubMed ID: 30145821Telomerase has a critical role in cell proliferation, tumor maintaining, and therapy resistance, which act by modifying many signaling pathways. 2-[(E)-3-Naphtalen-2-yl-but-2-enoylamino]-benzoic acid (BIBR1532) is one of the most studied telomerase inhibitors, and it targets telomerase components TERC and TERT. In this novel study, we aimed to investigate the epigenetic effects of BIBR1532 on both hematologic malignancies and solid tumors. K-562 human chronic myeloid leukemia cell line and U87MG glioblastoma cell line were compared with control groups without BIBR1532 treatment. Cytotoxic effects of BIBR1532 were determined by using WST-1 assay. Apoptotic effects of BIBR1532 were detected by using annexin V method. To assess expression changes in the human epigenetic chromatin modification enzyme genes, total RNA was isolated from K-562 and U87MG cells treated with BIBR1532 and untreated control cells. BIBR1532 induced 2.41-fold apoptotic cell death in U87MG cell lines compared with control groups. Apoptosis was slightly induced in K-562 cells with BIBR1532 treatment compared with control cells. We observed that BIBR1532 also regulates similar genes in both cell lines, and it is useful on epigenetic mechanisms. As a result, telomerase inhibitor BIBR1532 has a significant effect on both hematological malignancies and solid tumors

Targeting TdT gene expression in Molt-4 cells by PNA-octaarginine conjugates

Charoudeh, Hojjatollah Nozad/0000-0003-4883-9924WOS:000588093700435PubMed: 32941907Peptide nucleic acid (PNA) is an amide based structural nucleic acid mimic with potential applications in gene therapeutic drug discovery. in the present study, we evaluated and compared the effects on gene expression, cell viability and apoptosis of two antisense PNA-D-octaarginine conjugates, targeting sequences at the AUG translation start site or the 5 '-UTR of the TdT (terminal deoxynucleotidyl transferase) gene, as well as a sense oligomer corresponding to the 5 '-UTR-antisense, in Molt-4 cells. The protein level of TdT was determined by flow cytometry, and qPCR was used for mRNA expression analysis. Mismatch PNAs were used as control to address the sequence/target spcifity of the biological effects. The results showed that treatment with the AUG- and to slightly lesser extent with the 5'-UTR-antisense PNAs reduced the TdT mRNA as wel as the protein level, whereas only very low effect was observed for the 5 '-UTR-sense PNA. A parallel effect was observed on reduced cell survival and increased rate of apoptosis. Our findings suggest that antisense PNAs can inhibit expression of the TdT gene and induce apoptosis in Molt-4 cells. (C) 2020 Elsevier B.V. All rights reserved.Molecular Medicine Research Center, Tabriz University of Medical Sciences, Tabriz [TBZMED.REC.1394.1104]This work was supported by Molecular Medicine Research Center, Tabriz University of Medical Sciences, Tabriz with the ethical code of TBZMED.REC.1394.1104

The role of EGFR overexpression on the recurrence of basal cell carcinomas with positive surgical margins

WOS: 000456753500006PubMed ID: 30419251Background: Epidermal growth factor receptor (EGFR) expression may have role on recurrence of basal cell carcinoma (BCC) with positive surgical margin(s). Objective: The aim was to investigate the role of genetic expression changes of EGFR on recurrence rates in patients in follow up with surgically excised BCC with positive surgical margin(s). Methods: Thirty-four surgical margin positive BCC lesions that were closely followed up without an immediate reoperation were included in this study. Real-time polymerase chain reaction (PCR) was performed from the both healthy and tumoral tissue samples. Results: EGFR was expressed at a significantly higher rate in tumoral tissues compared to healthy tissues (p < 0,05). In patients with recurrence lesions, EGFR expression was 6,66 times higher compared to patients with non-recurrent. Also, there was statistically significant difference EGFR expression for infiltrative subtypes (p < 0,05). Conclusion: Our study focuses on the role of EGFR overexpression specifically and outcomes for recurrent and infiltrative subtyped lesions are significant for both clinic and pathogenesis of BCC. Similar studies have to be performed with high numbered patient groups