S100A4 in esophageal cancer: Is this the one to blame?

Cytokine Interaction With Cancer-Associated Fibroblasts in Esophageal Cancer

Esophageal cancer (EC) is a highly aggressive cancer with poor outcomes under current treatment regimens. More recent findings suggest stroma elements, specifically cancer-associated fibroblasts (CAFs), play a role in disease occurrence and progression. Cancer-associated fibroblasts are largely the product of converted fibroblasts, but a variety of other local cell types including epithelial cells, endothelial cells, and mesenchymal cells have also been shown to transform to CAFs under the correct conditions. Cancer-associated fibroblasts primarily function in the communication between the tumor microenvironment and cancer cells via cytokine and chemokine secretions that accentuate immunosuppression and cancer growth. Cancer-associated fibroblasts also pose issues for EC treatment by contributing to resistance of current chemotherapeutics like cisplatin. Targeting this cell type directly proves difficult given the heterogeneity between CAFs subpopulations, but emerging research provides hope that treatment is on the horizon. This review aims to unravel some of the complexities surrounding CAFs’ impact on EC growth and therapy.

Multiple S100 protein isoforms and C-terminal phosphorylation contribute to the paralog-selective regulation of nonmuscle myosin 2 filaments

Nonmuscle myosin 2 (NM2) has three paralogs in mammals, NM2A, NM2B, and NM2C, which have both unique and overlapping functions in cell migration, formation of cell-cell adhesions, and cell polarity. Their assembly into homo- and heterotypic bipolar filaments in living cells is primarily regulated by phosphorylation of the N-terminally bound regulatory light chain. Here, we present evidence that the equilibrium between these filaments and single NM2A and NM2B molecules can be controlled via S100 calcium-binding protein interactions and phosphorylation at the C-terminal end of the heavy chains. Furthermore, we show that in addition to S100A4, other members of the S100 family can also mediate disassembly of homotypic NM2A filaments. Importantly, these proteins can selectively remove NM2A molecules from heterotypic filaments. We also found that tail phosphorylation (at Ser-1956 and Ser-1975) of NM2B by casein kinase 2, as well as phosphomimetic substitutions at sites targeted by protein kinase C (PKC) and transient receptor potential cation channel subfamily M member 7 (TRPM7), down-regulates filament assembly in an additive fashion. Tail phosphorylation of NM2A had a comparatively minor effect on filament stability. S100 binding and tail phosphorylation therefore preferentially disassemble NM2A and NM2B, respectively. These two distinct mechanisms are likely to contribute to the temporal and spatial sorting of the two NM2 paralogs within heterotypic filaments. The existence of multiple NM2A-depolymerizing S100 paralogs offers the potential for diverse regulatory inputs modulating NM2A filament disassembly in cells and provides functional redundancy under both physiological and pathological conditions.

Expression of metastasis related genes S100A4 and MMP-9 in pancreatic cancer cells treated with metformin

AIM

To investigate the expression of metastasis related genes S100A4 and matrix metalloproteinase (MMP)-9 in pancreatic cancer cell lines BxPC-3 and AsPC-1 treated with metformin.

METHODS

Cells were incubated with metformin at different concentrations for 24, 48, or 72 h. Then, cell viability was measured by MTT assay, and IC₅₀ values were calculated. The two cell lines were then treated with metformin at IC₅₀ concentrations for 48 h, and RT-PCR was used to detect the expression of S100A4 and MMP-9 mRNAs.

RESULTS

Cell viability was apparently inhibited by metformin in both cell lines, and the inhibitory effect showed a time- and dose-dependent manner. The IC₅₀ values for BxPC-3 cells at 24, 48, and 72 h were 12.13 mmol/L, 10.43 mmol/L, and 9.55 mmol/L, respectively, and the corresponding values for AsPC-1 cells were 23.45 mmol/L, 15.44 mmol/L, and 11.30 mmol/L. After treatment with metformin for 48 h, the expression of S100A4 and MMP-9 mRNAs in the two cell lines was significantly decreased compared with control cells (P < 0.01).

CONCLUSION

Metformin inhibits pancreatic cancer cell growth in a time- and dose-dependent manner. Metformin may exert anti-metastasis effects by decreasing the expression of S100A4 and MMP-9 in pancreatic cancer cell lines.

Impact of S100A4 Expression on Clinicopathological Characteristics and Prognosis in Pancreatic Cancer: A Meta-Analysis

BACKGROUND

The small Ca(2+)-binding protein S100A4 is identified as a metastasis-associated or metastasis-inducing protein in various types of cancer. The goal of this meta-analysis was to evaluate the relationship between S100A4 expression and clinicopathological characteristics and prognosis of patients with pancreatic cancer.

METHODS

A comprehensive literature search was carried out in the electronic databases PubMed and Chinese CNKI. Only the studies reporting the correlation between S100A4 expression and clinicopathological characteristics or overall survival (OS) of patients with pancreatic cancer are enrolled. Extracted data was analyzed using the RevMan 5.3 software to calculate the pooled relative risks (95% confidence interval, CI) for statistical analyses.

RESULTS

Seven studies including a total of 474 patients were enrolled into this meta-analysis. Negative expression of S100A4 was significantly associated with higher 3-year OS rate (RR = 3.92, 95% CI = 2.24-6.87, P < 0.0001), compared to S100A4-positive cases. Moreover, negative expression of S100A4 was also related to N0 stage for lymph node metastasis (RR = 2.15, 95% CI = 1.60-2.88, P < 0.0001). However, S100A4 expression was not significantly correlated with histological types and distant metastasis status.

CONCLUSION

S100A4 expression represents a potential marker for lymph node metastasis of pancreatic cancer and a potential unfavorable factor for prognosis of patients with this disease.

Deregulated miR-296/S100A4 axis promotes tumor invasion by inducing epithelial-mesenchymal transition in human ovarian cancer

S100A4 represents an important member of the S100 family of small calcium-binding proteins. Increased expression of S100A4 has been observed in chronic inflammatory and autoimmune diseases, such as idiopathic inflammatory myopathies. The majority of studies of S100A4 are focused on cancer research; however, the oncogenic roles of S100A4 in epithelial ovarian cancer (EOC) remain largely unexplored. In this study, S100A4 expression is significantly up-regulated in ovarian cancer and associated with the clinical stage of EOC patients. Attenuation of S100A4 expression results in decreased cell mobility and metastatic capacity, whereas overexpression of S100A4 enhanced the invasive ability of EOC cells. Then by an integrated informatics analysis and luciferase reporter assay, we identify that miR-296 is a critical upstream regulator of S100A4. In addition, deregulated miR-296/S100A4 axis facilitates epithelial-mesenchymal transition (EMT) process as demonstrated by altered expression of EMT-related markers. In conclusion, our study reveals that deregulated miR-296/S100A4 promotes tumor progression in EOC, and provides evidence that miR-296/S100A4 axis-related signaling may represent a potential target for EOC therapy.

Aberrant expression of S100A6 and matrix metalloproteinase 9, but not S100A2, S100A4, and S100A7, is associated with epidermal carcinogenesis

BACKGROUND

S100 proteins belong to a family of calcium-binding proteins that regulate cell proliferation and differentiation. Despite our growing knowledge about the biology of S100 proteins in some human cancers, little is known about the expression of S100 family members in epidermal tumors and their clinical significance.

OBJECTIVE

To determine the expression of S100A2, S100A4, S100A6, S100A7, as well as matrix metalloproteinases 9 (MMP9) in a spectrum of epidermal tumors with benign and malignant characteristics.

METHODS

Immunohistological staining was performed for S100A2, S100A4, S100A6, S100A7, and MMP9 in 101 cases of various types of epidermal tumors, viz., squamous cell carcinoma (SCC), Bowen's disease (BD), actinic keratosis (AK), basal cell carcinoma (BCC), keratoacanthoma (KA), and seborrheic keratosis (SK). Thirteen specimens of normal skin (NS) served as control.

RESULTS

S100A2, S100A6, and S100A7 positive immunostaining was variably observed in different epidermal tumors. S100A4 staining was not observed in any epidermal tumors, but was clearly visible in dendritic cells. MMP9 immunostaining was positive only in 22/26 (84.62%) of SCC and 2/15 (13.33%) of BD cases. Expression of S100A2, S100A6, and S100A7 was increased in tumor cells compared to NS. However, only S100A6 expression was significantly associated with malignant transformation of epidermal tumors. Moreover, S100A6 expression was correlated with MMP9 expression in metastatic SCC.

CONCLUSIONS

Epidermal tumors show increased expression of S100A2 and S100A7 proteins. S100A4 may be a useful and distinct marker for epidermal dendritic cells. Expression of S100A6 and MMP9 in combination is associated with the development of SCC.