Immunohistochemical and Molecular Detection of Mitochondrial Atpase 6 Gene Mutations in Bladder Cancer Among Sudanese Patients

Background: Mitochondrial DNA (mtDNA) dysfunction plays acritical role in carcinogenesis. Mutations in MT-ATPase 6 gene, encoding a subunit of mitochondrial complex V (ATP synthase), have been implicated in various cancers, but their prevalence in bladder cancer, particularly among Sudanese patients, remains unclear. Objective: This study aims to detect ATPase 6 gene mutations in bladder cancer tissue using immunohistochemistry (IHC) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and to correlate these alterations with clinicopathological parameters. Materials and Methods: A retrospective cohort study was conducted on 90 formalin-fixed paraffin-embedded (FFPE). Bladder cancer specimens from three major hospitals in Khartoum state (2020-2022). IHC was performed using an anti-ATPase 6 antibody. PCR-RFLP with HpaII digestion was used to detect mutations. Statistical analysis includes Chi-square test, with significance set (> 0.05). Results: The study comprised male (59 patients, 65.6%) compared to females (31 patients, 34.4%). The patients age ranged from (30 to 95) with mean age of (62.5) years old, the age was categorized as follow (30-51) were 32 patient (35.6%), (52-73) were 43 patient (47.8%), (74- 95) were 15 patient (16.7%). the prevalence of transitional bladder cancer (Seventy-six patients (84.4%) while 14 patients (15.6%) had other bladder cancer (leiomyosarcoma,) diagnoses. Regarding tumour grade, the distributions were as follows: 35 patients (38.9%) had high-grade tumours, 26 patients (28.9%) had low-grade tumours, and 29 patients (32.2%) had invasive tumours. The results also showed that 24 patients (26.7%) were positive for Schistosoma infection, while 66 patients (73.3%) were negative. Immunohistochemical (IHC) analysis showed the presence of expression in 10 out of 90 samples (11.1%), Polymerase Chain Reaction (PCR) results revealed the presence of mutations in the ATPase 6 gene sequence in only 10 out of 90 samples (11.1%), indicating a low mutation rate. No statistically significant association were found between ATPase 6 alterations and gender, age group, tumour grade, tumour type, or Schistosoma infection (p value > 0.05 for all).