Abstract
Prostate cancer (PCa) is a leading global health burden, with a particularly high prevalence in South Africa. Despite therapeutic advancements, chemoresistance remains a major challenge, limiting the efficacy of docetaxel and contributing to treatment failure and disease progression. Multidrug resistance (MDR), primarily mediated by ATP-binding cassette (ABC) transporters such as ABCC1 and ABCC10, has been implicated in reduced chemotherapy effectiveness. This study aimed to evaluate the association between ABCC1 and ABCC10 expression levels and docetaxel treatment response in PCa patients. A retrospective case-control study was conducted using pre-treated formalin-fixed paraffin-embedded (FFPE) tissue biopsies from PCa patients. Patients were classified into good responders (cases) and poor responders (cases) based on treatment outcomes. For each patient, tumour and adjacent normal sections were excised from FFPE samples, with normal sections serving as the control group. RNA was extracted and subjected to quantitative real-time PCR (qRT-PCR) to assess ABCC1 and ABCC10 expression levels. ABCC1 and ABCC10 were significantly upregulated in tumour sections of poor responders, whereas good responders exhibited downregulated expression in tumour sections. Importantly, normal tissue sections (controls) displayed significantly lower expression levels of both transporter genes compared to tumour sections. The overexpression of ABCC1 and ABCC10 in tumour tissues, particularly in poor responders, suggests their potential role in mediating docetaxel resistance. These findings highlight ABCC1 and ABCC10 as potential predictive biomarkers for docetaxel treatment response in PCa, warranting further investigation in prospective clinical studies.