Both UA and OA have antitumor effects on cancer cells with MDR, and the optimal effect is shown by UA on colonic cancer cells. Also, UA shows cell apoptosis-inducing effect on SW480, possibly by way of down-regulating the expressions of apoptosis antagonistic proteins, Bcl-2, Bcl-xL, and survivin.
Normal fibroblasts produce extracellular matrix (ECM) components that form the structural framework of tissues. Cancer-associated fibroblasts (CAFs) with an activated phenotype mainly contribute to ECM deposition and construction of cancer masses. However, the stroma of breast cancer tissues has been shown to be more complicated, and the mechanisms through which CAFs influence ECM deposition remain elusive. In this study, we found that the activated fibroblast marker α-smooth muscle actin (α-SMA) was only present in the stroma of breast cancer tissue, and the CAFs isolated from invasive breast cancer sample remained to be activated and proliferative in passages. To further assess the difference between CAFs and normal breast fibroblasts (NFs), MALDI TOF/TOF‑MS was used to analyze the secretory proteins of primary CAFs and NFs. In total, 2,903 and 3,023 proteins were identified. Mass spectrum quantitative assay and data analysis for extracellular proteins indicated that the CAFs produce less collagens and matrix-degrading enzymes compared with NFs. This finding was confirmed by western blot analysis. Furthermore, we discovered that reduced collagen deposition was present in the stroma of invasive breast cancer. These studies showed that although CAFs from invasive breast cancer possess an activated phenotype, they secreted less collagen and induced less ECM deposition in cancer stroma. In cancer tissue, the remodeling of stromal structure and tumor microenvironment might, therefore, be attributed to the biological changes in CAFs including their protein expression profile.
Background: The aim of this study was to investigate the expression of caveolin-1 (Cav-1) in cancer-associated fibroblasts (CAFs) and to explore its correlation with clin- icopathologic parameters and prognosis. Materials and Methods: Cav-1 expression was detected in the stroma of 143 patients with breast cancer, 10 patients with ductal carcinoma in situ (DCIS), and 10 normal breast tissue samples. Results: Overexpression of stromal Cav-1 in breast cancer was associated with histological type, low histological grade, estrogen receptor (ER) negativity, and molecular subtypes. The expression rate of stromal Cav-1 in breast cancer (65.7%, 94/143) was significantly higher than that of DCIS (0%, 0/10) and normal breast tissue (0%, 0/10) (p = 0.000). A positive correlation was found between stromal Cav-1 and ER (p = 0.046, rs = 0.218). Stromal Cav-1 expression in lumi- nal B was significantly higher than in basal-like type (p = 0.048). Furthermore, stromal expression of Cav-1 was significantly correlated with the 5-year survival rate (p = 0.029), and it was an independent prognostic factor (p = 0.009). Conclusion: Cav-1 expression in CAFs was correlated with histological type, histological grade, ER status, and molecular subtypes in breast cancer. Stromal Cav-1 expression was an independent prognostic factor, and the absence or reduction of Cav-1 expression in stromal CAFs of invasive breast cancer predicts poor prognostic outcome.
Abstract:Objective: Cancer-associated fibroblasts (CAFs) are one of the hallmarks of the cancer microenvironment. Recent evidence has indicated that CAFs are more competent in enhancing cancer cell growth and migration than normal fibroblasts. However, the unique protein expression of CAFs has not been fully elucidated. This study aims to investigate the characterizations of colon CAFs by comparing the differential protein expression between CAFs and normal fibroblasts. Methods: Primary fibroblasts were isolated from surgical specimen of human colon cancer and matched normal colonic tissue. Purity of the cell population was verified through immunostain analysis. Total cell lysates and conditioned media from each group of cells were extracted, and protein expression analysis was conducted using the surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) ProteinChip platform. Results: Most primary cells showed typical fibroblast-like features after two weeks. Increased proportion of α-smooth muscle actin-positive myofibroblasts was detected within the CAFs in four of the six pairs of primary cells. Fibroblast activation protein was weakly expressed in most cells without differences. Using SELDI-TOF-MS ProteinChip platform, four protein peaks mass over charge ratio (m/z) 1142, 3011, 4035, and 4945 were detected in the total cell lysates, and two protein peaks m/z 1368 and 1389 were detected in the conditioned media. The potential candidate proteins found in the Swiss-Prot database include morphogenetic neuropeptides, FMRFamide-related peptides, insulin-like growth factor II, thymosin β-4-like protein 3, and tight junction-associated protein 1. Conclusions: Using the SELDI-ProteinChip platform, differential protein expressions were identified in colon CAFs compared with normal colonic stromal fibroblasts. The complex proteomic alternations in colon CAFs may play important roles related to the colon cancer microenvironment.
Abstract:Objective: Cancer stromal fibroblasts are important members of the cancer microenvironment. In this study, we determined the effect of sunitinib, a small molecule tyrosine kinase inhibitor, on the primary human colonic fibroblasts. Methods: Cell cycle analysis and cell proliferation assays were performed to evaluate the inhibitory effect of sunitinib in vitro. Western-blot analysis was performed to evaluate variations in the levels of phosphorylated plateletderived growth factor receptor β (PDGFR-β), Akt, and ERK proteins. Co-injection of SW620 cells and colonic fibroblasts in nude mice was employed to test anti-growth efficacy in vivo. Results: Sunitinib was found to effectively inhibit the growth of primary colonic fibroblasts. Low-dose sunitinib blocked the PDGF-BB-induced cell proliferation and PDGFR-β signaling. Co-injection of SW620 cells and colonic fibroblasts in nude mice generated greater tumor volumes than single injection of SW620 cells. Sunitinib treatment inhibited the SW620 cell+colonic fibroblast tumor growth more effectively than treatment of 5-fluorouracil. Conclusions: Sunitinib mesylate inhibited the proliferation of primary human colonic fibroblasts through target-inhibited PDGFR signaling in vitro and in vivo.
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