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Updated: May 31, 2026
Clinicopathological Analysis of miRNA Expression in Breast Cancer Tissues by Using miRNA In Situ Hybridization
Published on: June 7, 2016
Correlation of Smac/DIABLO protein expression with the clinico-pathological features of breast cancer patients
P Pluta1, B Cebula-Obrzut, V Ehemann
1Department of Surgical Oncology, Medical University of Lodz, Copernicus Memorial Hospital, Lodz, Poland. piortrpluta@op.pl
Abstract:
Smac/DIABLO protein promotes caspase-dependent apoptosis by inhibition of inhibitor of apoptosis protein (IAP) family members. The role of Smac/DIABLO in breast cancer has not been yet established. Therefore, the aim of the study was to assess the expression of this protein in tumor cells from breast cancer patients. The expression of Smac/DIABLO was analyzed in 62 breast cancer patients by flow cytometry. The obtained results were compared with expression of this protein in benign breast tumor tissue, which served as the control (11 patients with fibroadenoma). Expression of caspase-3 proteins in breast cancer was also evaluated. Smac/DIABLO expression in breast cancer was correlated with clinical and pathological data. Although the expression of Smac/DIABLO protein was found in all examined samples of both the breast cancer and fibroadenoma patients, the median expression of Smac/Diablo in breast cancer was significantly lower than in the control (39.1% vs. 48.1%; p=0.0047). Smac/DIABLO expression correlated with expression of caspase-3 (p=0.000008). In pT1 breast cancer patients, expression of Smac/DIABLO protein was higher than in those with pT2-3 (p=0.02). Diffuse cancer infiltration significantly correlated with lower expression of Smac/DIABLO protein (p=0.02). Moreover, there was a loose correlation between low expression of Smac/DIABLO protein and cancer embolus in minor blood and lymphatic vessels (p=0.08). Our results indicate that expression of Smac/DIABLO inversely correlates with the tumor stage, which may suggest that this protein may play an important role in the breast cancer development.
Insights
Smac/DIABLO protein expression is lower in breast cancer than benign tissue and inversely correlates with tumor stage and infiltration, suggesting a role in breast cancer development.
Area of Science:
- Molecular Biology
- Oncology
- Cell Death Pathways
Background:
- Smac/DIABLO protein promotes apoptosis by inhibiting IAP proteins.
- The role of Smac/DIABLO in breast cancer pathogenesis is not well understood.
Purpose of the Study:
- To investigate Smac/DIABLO protein expression in breast cancer tissues.
- To correlate Smac/DIABLO expression with clinical and pathological features of breast cancer.
Main Methods:
- Flow cytometry was used to analyze Smac/DIABLO expression in 62 breast cancer patients and 11 fibroadenoma controls.
- Expression of caspase-3 was also evaluated.
- Correlation with clinical-pathological data was performed.
Main Results:
- Smac/DIABLO expression was detected in all samples, but was significantly lower in breast cancer (39.1%) compared to fibroadenoma (48.1%).
- Smac/DIABLO expression positively correlated with caspase-3 expression and inversely with tumor stage (higher in pT1 vs. pT2-3).
- Lower Smac/DIABLO expression correlated with diffuse cancer infiltration and showed a trend with cancer embolus presence.
Conclusions:
- Smac/DIABLO expression is reduced in breast cancer and inversely correlates with tumor progression.
- These findings suggest Smac/DIABLO may function as a tumor suppressor in breast cancer development.
