Probes for INS

Abstract: Objective: To investigate the potential involvement of secreted protein acidic and rich in cysteine (SPARC) in the progression of the breast tumor and to determine its association with outcome variables and matrix metalloproteinases (MMPs) expression in patients with breast carcinoma (BC). Methods: SPARC expression was examined in 8 pairs of BC tissues and surrounding normal tissues at mRNA and protein levels by qRT-PCR, RNAscope in situ hybridization (ISH), Western blotting, and immunohistochemistry techniques. Immunohistochemical staining of SPARC was done in 26 normal breasts, 76 ductal carcinoma in situ (DCIS), and 198 BC samples. In addition, immunohistochemical staining was performed for MMP-2 and MMP-9 in BC. Results: SPARC expression at mRNA and protein levels was significantly increased in BC tissues compared to the surrounding normal tissues (P < 0.05 and P < 0.01, respectively). RNAscope ISH and immunohistochemistry of SPARC confirmed an increase in SPARC expression in BC tissues compared with the normal tissues. Epithelial SPARC expression increased continuously from normal breast through DCIS to BC (P < 0.001). In patients with BC, high epithelial SPARC expression was associated with worse disease-free survival and overall survival (P = 0.002 and P = 0.048, respectively) and independently predicted worse disease-free survival (P = 0.002). Epithelial SPARC expression was significantly correlated with MMP-2 expression (P < 0.05). Conclusion: Up-regulation of SPARC contributes to breast tumor progression. SPARC expression may be a useful biomarker for the prognostic prediction in patients with BC. SPARC can control extracellular matrix degradation through up-regulation of MMP-2.

Secreted protein acidic and rich in cysteine (SPARC) plays an essential role in tumor invasion and metastasis. The present work was undertaken to detect expression of SPARC mRNA in phyllodes tumors (PTs) and its association with SPARC protein expression. This study also evaluated expression of SPARC mRNA and its correlation between grade and clinical behavior of PTs. In addition, we assessed in PTs the association of expression of SPARC with that of matrix metalloproteinase (MMP)-2 and of MMP-9. SPARC mRNA expression was determined by RNAscope in situ hybridization (ISH) in 50 benign, 22 borderline, and 10 malignant PTs using a tissue microarray. Furthermore, we applied immunohistochemistry (IHC) to examine expression of SPARC, MMP-2, and MMP-9. SPARC mRNA appeared to be concentrated mainly in the stromal compartment of PTs. IHC staining patterns of SPARC protein showed concordance with SPARC mRNA ISH results. Stromal SPARC expression increased continuously as PTs progress from benign through borderline to malignant PTs, both at mRNA (using ISH) (P = 0.044) and protein level (using IHC) (P = 0.000). The recurrence percentage was higher in the stromal SPARC mRNA or protein-positive group than in the SPARC-negative group but this difference was not statistically significant. Stromal SPARC mRNA and protein expression was associated with PT grade and correlated with MMP-2 expression. These results indicate that SPARC-mediated degradation of the extracellular matrix, and its possible association with MMPs, might contribute to progression of PTs.