الملخص الإنجليزي
Background: Epithelial ovarian cancer (EOC) is a malignant tumor found in 90
% of ovarian cancer. Although bio-molecular techniques have identified
biomarkers, yet none of them is reliable. Thus understanding the underlying
molecular mechanism of EOC is essential to identify biomarkers for improving
survival rates. In a previous study held in Biochemistry Dpt., SQU, it has been
reported that BRIP1 is one of the genes regulated by E2F5 which is a
transcription factor that has been shown to be overexpressed in EOC. BRIP1,
BRCA1, and BRCA2 genes were among a total of 140 candidate genes shortlisted
as downstream genes of E2F5. These genes are described as DNA repair genes
as well as ovarian cancer susceptibility genes. Till date the mechanism ruled by
BRIP1-BRCA1/2 interaction in EOC is not known
Aim: To Investigate the Role of BRIP1 in Epithelial Ovarian Cancer
Pathogenicity.
Method: Expression of BRIP1 gene was determined in four ovarian cancer cell
lines using quantitative real time PCR (qRT-PCR). We knocked-down
BRIP1gene in moderate BRIP1expressing cell line (MCAS) using siRNA,
verified it at the mRNA level, and performed functional analysis. Alamar blue
cell viability reagent was used to test the effect of BRIP1 silencing on
proliferation. Change in BRCA1/2 expression following BRIP1 knockdown was
determined by qRT-PCR. Migration and invasion level following BRIP1
knockdown, was tested using wound healing and invasion assays respectively.
MTT assay was performed to investigate the survival rate of BRIP1-knocked
down MCAS cells following cisplatin treatment. Bioinformatic analysis was
further done using different databases.
Results: BRCA1 and BRCA2 genes were downregulated following BRIP1
silencing (p = 0.0009, 0.0045). Proliferation, invasion, and migration were
significantly increased following BRIP1 downregulation (p = 0.0419, 0.0286,
0.0196). Higher survival rate following cisplatin treatment was observed in
BRIP-knocked down cells (p <0.0001). cBioportal bioinformatic analysis
revealed rare mutations in BRIP1 in EOC, and moderately correlated with
BRCA genes, BARD1, and PALB2. 90 micro RNAs were found in interaction
with BRIP1 through Arena Idb databse.
Conclusion: Knockdown of BRIP1 drives the down-regulation of BRCA genes
and enhances cancerous characteristics such as proliferation, invasion,
migration, and drug resistance.
