Induction of Mesenchymal-Epithelial Transition (MET) in HT29 Cell Line Containing Cancer Stem-Like Cell (HT29-shE) withDifferentiation Therapy Purpose for Cancer Treatment

Background and Aim: Radiation therapy and chemotherapy forcancer treatment can be highly toxic and nonspecific sometimes.Newer therapeutic approaches recommend the use of chemotherapyin combination with other treatment modalities. Sox2 and Oct4 aretranscriptional master regulators which express in various human tumors,so that can give rise to tumor growth promotion through interfering withprogenitor cell differentiation. In the present study, inhibition of Sox2 andOct4 transcription factors using oligodeoxynucleotide decoy strategylead to mesenchymal-epithelial transition (MET) in HT29-shE cell line.Methods: E-cadherin knockdown in HT29-shE cell line lead to theenrichment of cancer stem-like cells. Sox2 and Oct4 decoy and itsscramble ODNs designed and synthesized. Also, EMSA assay was usedto confirm the specificity interaction of ODNs decoy with their proteins.Then, ODNs transfected into cells with Lipofectamine and its subcellularlocalization determined by fluorescence and confocal microscopy. Cellviability, apoptosis and downstream genes expression in HT29-shEcells were analyzed by MTT, Annexin V/ PI test, and Real-time assays,respectively.Results: EMSA data showed that Sox2-Oct4 decoy ODNs boundspecifically to their proteins in nuclear extract of HT29-shE cells. Theresults revealed that the designed complex decoy can concomitantlytarget Sox2 and Oct4, which subsequently induction of MET in HT29-shE cells compared to controls through decreasing cell viability, arrestingthe cell cycle in G0/G1 phases, inducing apoptosis, and modulatingdifferentiation process.Conclusion: Use of Sox2-Oct4 TFD strategy in HT29-shE cells can leadinhibiting cell growth and triggering differentiation. Hence, this strategycan be used in combination with conventional treatment modalities as apromising tool in cancer therapy.

Keywords:

Cancer stem-like cell , Oligodeoxynucleotide decoy , Oct4 and Sox2 transcription factors , Antitumor effects , Differentiation therapy