Akademik Veri Yönetim Sistemi
Tezin Türü: Doktora
Tezin Yürütüldüğü Kurum: Bursa Uludağ Üniversitesi, FEN-EDEBİYAT FAKÜLTESİ, BİYOLOJİ, Türkiye
Tezin Onay Tarihi: 2018
Tezin Dili: Türkçe
Öğrenci: BUSE CEVATEMRE
Danışman: Egemen Dere
Özet:
Recently, mitochondria have attracted much attention in metastatic cancer research. There
are several reports showing that highly metastatic cancer cells preferentially use
glycolysis over mitochondrial respiration for energy production. Pyruvate dehydrogenase
enzyme complex (PDH), the gatekeeper enzyme of mitochondria is shown to be
responsible for this switch in some cancers. Epithelial mesenchymal transition (EMT),
has been proposed to be a driving force of metastasis. In this study, the existence of a link
between EMT and cancer cell metabolism has been investigated. To inhibit PDH activity,
pharmacological (PDH inhibitor, Cpi-613) and RNAi (stable cell lines were established
by lentivirus) were used in A-549 cells. The antiproliferative effect of Cpi-613 was
investigated by xCELLigence System, SRB and ATP viability assays. Wound healing,
invasion and drug sensitivity tests were applied at antiproliferative doses. To demonstrate
the EMT phenotype in cells, the expression of EMT-related proteins were analyzed via
western blotting. Furhermore, SB-431542 (TGF-β receptor inhibitor) was used to test
whether Cpi-613 induced EMT depends on TGF-β signalling. As a result both the
inhibition of PDH by Cpi-613 and the knockdown of PDHA1 induced morphological
changes, which were characteristics of EMT. A more rapid wound healing, increased
invasive potential and chemoresistance were also shown. SB-431542 treatment reversed
the EMT phenotype. The proportion of CD133+ (a cancer stem cell marker) cells were
also higher in shPDHA1 cells than those of shControl cells. In brief, knockdown of
PDHA1 expression or inhibition of PDH activity induced the EMT phenotype and more
importantly resulted in resistance to chemotherapeutic drugs. Therefore, the use of Cpi-
613 or PDH blockers becomes debatable for use in anticancer therapy.
Keywords: Lung cancer, epithelial mesenchymal transition, drug resistance, cancer cell