MSc Thesis Defense: Esra Akkuş, EXPLORING THE EVOLUTION OF TRIPLE-NEGATIVE BREAST CANCER HETEROGENEITY VIA OXPHOS- GLYCOLYSIS BIOSENSORS, Date & Time: 16 July, 2026 – 2:00 PM, Place: FMAN G013

EXPLORING THE EVOLUTION OF TRIPLE-NEGATIVE BREAST CANCER HETEROGENEITY VIA OXPHOS- GLYCOLYSIS BIOSENSORS

Esra Akkuş
Molecular Biology, Genetics and Bioengineering, MSc Thesis, 2026

Thesis Jury

Asst. Prof. ALEX LYAKHOVICH (Thesis Advisor)

Prof. LEVENT ÖZTÜRK

Prof. KIVANÇ BİLECEN

Date & Time: 16th July, 2026 –  2.00 PM

Place: FMAN G013

Keywords : Triple-Negative Breast Cancer (TNBC), mitochondrial bioenergetics, chemoresistance, CRISPR/Cas9 biosensors, mitochondrial transplantation

Abstract

This thesis investigates the metabolic evolution of Triple-Negative Breast Cancer (TNBC) from a chemo-sensitive to a therapy-resistant phenotype, focusing on mitochondrial bioenergetics. While glycolysis has defined malignant tumor metabolism, this research focuses it as a non-universal phenomenon. We propose a model of metabolic plasticity in which aggressive, slowly dividing cancer subpopulations survive therapeutic stress by shifting energy production toward mitochondrial oxidative phosphorylation (OXPHOS). Consistent with this, elevated OXPHOS gene expression correlates with reduced overall survival in post-chemotherapy breast cancer patients. To map real-time bioenergetic transitions, we developed CRISPR/Cas9 knock-in biosensors (NDUFA4-eGFP for OXPHOS; HK2-mScarlet for glycolysis), together enabling visual tracking of bioenergetic transitions as sensitive cells evolve resistance and identification of subpopulations relying on functional mitochondria to evade treatment. To establish causality between mitochondrial state and resistance, we generate cytoplasmic hybrid (cybrid) lines by fusing mtDNA-depleted (ρ0) recipient cells with donor mitochondria from resistant or sensitive cancer cells. Transplanting "chemoresistant" mitochondria into a sensitive nuclear background tests whether mitochondrial function alone drives resistance. Together, this project establishes biosensor and cybrid models that causally link mitochondrial bioenergetics to TNBC chemoresistance, laying groundwork for future strategies targeting metabolic re-sensitization and plasticity in resistant breast cancers.