Evaluation of KISS1 Receptor Gene Expression in Egyptian Female Patients with Breast Cancer.

OBJECTIVE: Breast cancer is the second most common cancer in the world. Many metastasis suppressor genes were identified, including the KISS1 gene which encodes for a 145 amino acid protein (kisspeptin-145), which undergoes proteolytic cleavage resulting in kisspeptin-14, -13 and -10. All of these proteins can activate KISS1 receptor (KISS1R). The role of KP/KISS1R signaling in breast cancer remains controversial. The present study aimed to measure mRNA gene expression of KISS1 receptor in healthy and cancerous breast tissue and to evaluate the association of its level with the available molecular subtypes and the traditional clinico-pathological variables. METHODS: The study was done on 41 operable primary breast cancer patients. Biopsies from both tumor tissue and surrounding healthy mammary tissue were taken from all patients. KISS1R mRNA expression level was measured using a quantitative real time PCR.   Results: KISS1R mRNA expression was significantly higher in stage III patients compared to stage II patients. At a cut-off value for KISS1R mRNA expression of 1.75, stage II was discriminated from stage III. A significant positive correlation was found between KISS1R mRNA expression and tumor size as well as lymph nodes metastasis. KISS1R mRNA was highly expressed in ER negative cases compared to ER positive ones, and in PR negative cases compared to PR positive ones. There was a statistically significant difference in KISS1R mRNA expression levels and different molecular subtypes being over-expressed in HER2 and triple negative cancer cases. CONCLUSION: This study supports other studies suggesting that KISS1/KISS1R may not be acting as a metastasis suppressor in breast cancer. KISS1R mRNA is over expressed in advanced stages of breast cancer and hence it can be used as a prognostic marker for aggressiveness of breast cancer. Also being over expressed in triple negative patients, KISS1R could represent a promising therapeutic target in triple negative cases.

Potential value of circulatory microRNA10b gene expression and its target E-cadherin as a prognostic and metastatic prediction marker for breast cancer.

BACKGROUND: Breast cancer (BC) is the leading cause of cancer death in women worldwide. Most BC studies on candidate microRNAs were tissue specimen based. Recently, there has been a focus on the study of cell-free circulating miRNAs as promising biomarkers in (BC) diagnosis and prognosis. Therefore, we aimed to investigate the circulating levels of miR-10b and its target soluble E- cadherin as potentially easily accessible biomarkers for breast cancer. METHODS: Sixty-one breast cancer patients and forty-eight age- and sex-matched healthy volunteers serving as a control group were enrolled in the present study. Serum samples were used to assess miRNA10b expression by TaqMan miRNA assay technique. In addition, soluble E-cadherin expression level in serum was determined using ELISA technique. RESULT: Circulating miR-10b expression level and serum sE-cadherin was significantly upregulated in patients with BC compared to controls. Moreover, serum miR-10b displayed progressive up-regulation in advanced stages with higher level in metastatic compared to non-metastatic BC. Additionally, the combined use of both serum miR-10b and sE-cadherin revealed the highest sensitivity and specificity for detection of BC metastasis (92.9% and 97.9% respectively) with an area under curve (AUC) of 0.98, 95% CI (0.958-1.00). CONCLUSION: Our data suggest that circulating miR-10b could be utilized as a potential non-invasive serum biomarker for diagnosis and prognosis of breast cancer with better performance to predict BC metastasis achieved on measuring it simultaneously with serum sE-cadherin. Further studies with a large cohort of patients are warranted to validate the serum biomarker for breast cancer management.