S100A11 is a migration-related protein in laryngeal squamous cell carcinoma

S100A11 promotes focal adhesion disassembly via myosin II-driven contractility and Piezo1-mediated Ca2+ entry

S100A11 is a small Ca2+-activatable protein known to localize along stress fibers (SFs). Analyzing S100A11 localization in HeLa and U2OS cells further revealed S100A11 enrichment at focal adhesions (FAs). Strikingly, S100A11 levels at FAs increased sharply, yet transiently, just before FA disassembly. Elevating intracellular Ca2+ levels with ionomycin stimulated both S100A11 recruitment and subsequent FA disassembly. However, pre-incubation with the non-muscle myosin II (NMII) inhibitor blebbistatin or with an inhibitor of the stretch-activatable Ca2+ channel Piezo1 suppressed S100A11 recruitment, implicating S100A11 in an actomyosin-driven FA recruitment mechanism involving Piezo1-dependent Ca2+ influx. Applying external forces on peripheral FAs likewise recruited S100A11 to FAs even if NMII activity was inhibited, corroborating the mechanosensitive recruitment mechanism of S100A11. However, extracellular Ca2+ and Piezo1 function were indispensable, indicating that NMII contraction forces act upstream of Piezo1-mediated Ca2+ influx, in turn leading to S100A11 activation and FA recruitment. S100A11-knockout cells display enlarged FAs and had delayed FA disassembly during cell membrane retraction, consistent with impaired FA turnover in these cells. Our results thus demonstrate a novel function for S100A11 in promoting actomyosin contractility-driven FA disassembly.

Inhibitory Effect of S100A11 on Airway Smooth Muscle Contraction and Airway Hyperresponsiveness

OBJECTIVE

S100A11 is a member of the S100 calcium-binding protein family and has intracellular and extracellular regulatory activities. We previously reported that S100A11 was differentially expressed in the respiratory tracts of asthmatic rats as compared with normal controls. Here, we aimed to analyze the potential of S100A11 to regulate both allergen-induced airway hyperresponsiveness (AHR) as well as acetylcholine (ACh)-induced hypercontractility of airway smooth muscle (ASM) and contraction of ASM cells (ASMCs).

METHODS

Purified recombinant rat S100A11 protein (rS100A11) was administered to OVA-sensitized and challenged rats and then the AHR of animals was measured. The relaxation effects of rS100A11 on ASM were detected using isolated tracheal rings and primary ASMCs. The expression levels of un-phosphorylated myosin light chain (MLC) and phosphorylated MLC in ASMCs were analyzed using Western blotting.

RESULTS

Treatment with rS100A11 attenuated AHR in the rats. ASM contraction assays showed that rS100A11 reduced the contractile responses of isolated tracheal rings and primary ASMCs treated with ACh. In addition, rS100A11 markedly decreased the ACh-induced phosphorylation of the myosin light chain in ASMCs. Moreover, rS100A11 also suppressed the contractile response of tracheal rings in calcium-free buffer medium.

CONCLUSION

These results indicate that S100A11 protein can relieve AHR by relaxing ASM independently of extracellular calcium. Our data support the idea that S100A11 is a potential therapeutic target for reducing airway resistance in asthma patients.

Evaluation of calcium-binding protein A11 promotes the carcinogenesis of hypopharygeal squamous cell carcinoma via the PI3K/AKT signaling pathway

BACKGROUND

The S100 gene family encodes low molecular weight proteins implicated in cancer progression. In the present study, we explored the effects and underlying mechanisms of calcium-binding protein A11 (S100A11 protein) in hypopharyngeal squamous cell carcinoma (HSCC).

METHODS

RT-qPCR and western blot analysis were used to detect the mRNA and protein expression of S100A11, EGFR, MMP2, CD44, and MMP9. CCK-8, colony formation, wound healing and transwell invasion assays were performed to evaluate the effects of S100A11 on HSCC cells.

RESULTS

In our study, we observed that the level of S100A11 expression was significantly upregulated in HSCC tissues and cell lines. S100A11 inhibition increased the effects of 5-Fu on FaDu cells proliferation in vitro. In addition, S100A11 inhibition decreased the migration ability of FaDu cells. Additionally, the expression of migration-related proteins including EGFR, MMP2, CD44, and MMP9 were down-regulated when S100A11 was knocked down. Moreover, the expression of phosphorylated-PI3K (p-PI3K), phosphorylated-Akt (p-Akt), phosphorylated-mTOR (p-mTOR) and BCL-2 in FaDu cells were dramatically decreased.

CONCLUSIONS

Our results suggested that S100A11 could activate the PI3K/Akt/mTOR signaling pathway in HSCC tumorigenesis.

S100A6 activates EGFR and its downstream signaling in HaCaT keratinocytes

Epidermal growth factor receptor (EGFR) is a central transmitter of mitogenic signals in epithelial cells; enhanced EGFR activity is observed in many tumors of epithelial origin. S100A6 is a small calcium-binding protein, characteristic mainly of epithelial cells and fibroblasts, strongly implicated in cell proliferation and upregulated in tumors. In this study, using biochemical assays along with immunohistochemical and immunocytochemical analysis of organotypic and standard cultures of HaCaT keratinocytes with S100A6 overexpression or knock-down, we have examined the effect of S100A6 on EGFR activity and downstream signaling. We found that HaCaT cells overexpressing S100A6 had enhanced EGFR, phospho EGFR, and phospho extracellular signal-regulated kinase 1/2 (pERK1/2) staining intensity and level coupled to higher signal transducer and activator of transcription 3 (STAT3) activity. Conversely, S100A6 knockdown cells had impaired EGFR signaling that could be enhanced by addition of recombinant S100A6 to the culture media. Altogether the results show that S100A6 may exert its proproliferative effects through activating EGFR.

Dione-thiophene conjugate inhibits proliferation and metastasis of nasopharyngeal carcinoma cells through calcium binding protein-P down-regulation

In the present study a series of dione-thiophenol conjugates was prepared and evaluated against nasopharyngeal carcinoma (NPC) cells. MTT assay showed that compound 4a reduced proliferation of C666-1 and CNE-1 cells to 26 and 24%, respectively at 10 μmol/l concentration. Flow cytometry revealed that increasing the concentration of compound 4a from 2 to 10 μmol/l increased the proportion of early apoptotic C666-1 cells from 2.76 to 69.43%. A significant (P < 0.001) decrease in the expression of S100P was caused by compound 4a. In compound 4a treated C666-1 cells the expression of RAGE, EGFR, CD44, MMP2 and MMP9 was markedly decreased. In summary, compound 4a inhibits nasopharyngeal cancer cell proliferation and induces apoptosis through down-regulation of S100P. Moreover, compound 4a also decreases MMP-2, MMP-9, EGFR, CD44 and RAGE expression in nasopharyngeal cancer cells. Thus, compound 4a can be investigated further as a drug candidate for the treatment of nasopharyngeal cancer.

HGF-mediated S100A11 overexpression enhances proliferation and invasion of gastric cancer

S100 proteins are a group of low molecular weight (10-12 kDa) acidic proteins belonging to the largest family of EFhand calciumbinding proteins. S100A11, also known as S100C or calgizzarin, is an important member of the S100 family. S100A11 overexpression has been reported in a number of cancers including papillary thyroid carcinoma, colon, pancreatic, and breast cancer. One other study demonstrated that increased S100A11 expression is correlated with gastric cancer metastasis and poor overall disease prognosis. This study aimed to identify the function of S100A11 associated with cell proliferation and invasion in gastric cancer. We used cell culture, western blotting, reverse transcription-polymerase chain reaction, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and S100A11 knock-down with short hairpin ribonucleic acid (shRNA). First, we confirmed that the S100A11 expression was upregulated by hepatocyte growth factor (HGF). The role of S100A11 was determined via knock down of S100A11. S100A11-shRNA cells showed decreased levels of metalloproteinase-9 (MMP9) and nuclear factor kappa-B (NF-κB). We also examined and confirmed the role of HGF-mediated S100A11 expression. HGF-mediated cell proliferation and in vitro invasion increased, and HGF-mediated apoptosis decreased in S100A11 knockdown cells. We identified the putative binding site of NF-κB in the MMP9 promoter region and confirmed its function via chromatin immunoprecipitation (CHIP) assay. Our results showed that S100A11 is upregulated by HGF through the NF-κB pathway in gastric cancer and plays a role in cell proliferation and invasion in gastric cancer. It may thus be a possible target for gastric cancer therapy.

S100B as an Antagonist To Interfere with the Interface Area Flanked by S100A11 and RAGE V Domain

The Ca²⁺-sensing protein S100A11 of the S100 family is an important mediator of numerous biological functions and pathological conditions including cancer. The receptor for advanced glycation end products (RAGE) has been well accepted as the major receptor for several S100 family members. Here, we take the S100B protein as an antagonist to interfere with the interaction flanked by S100A11 and the RAGE V domain. We employed NMR spectroscopy to describe the interactions between the S100A11 and S100B proteins. ¹H-¹⁵N heteronuclear single-quantum correlation-NMR titrations showed the potential binding dynamics of S100A11 and S100B interactions. In the HADDOCK program, we constructed the S100A11-S100B heterodimer complex that was then superimposed with the S100A11-S100B complex structure in the same orientation as the S100A11-RAGE V domain complex. This overlay analysis showed that S100B could interfere in the binding section of S100A11 and the RAGE V domain. Additionally, water-soluble tetrazolium-1 assay provided a functional read-out of the effects of these proteins in an in vitro cancer model. Our study establishes that the development of an S100B antagonist could perform a vital part in the treatment of S100- and RAGE-dependent human diseases.

S100A11 protects against neuronal cell apoptosis induced by cerebral ischemia via inhibiting the nuclear translocation of annexin A1

The subcellular location of annexin A1 (ANXA1) determines the ultimate fate of neurons after ischemic stroke. ANXA1 nuclear translocation is involved in neuronal apoptosis after cerebral ischemia, and extracellular ANXA1 is also associated with regulation of inflammatory responses. As the factors and mechanism that influence ANXA1 subcellular translocation remain unclear, studies aiming to determine and clarify the role of ANXA1 as a cell fate ‘regulator’ within cells are critically needed. In this study, we found that intracerebroventricular injection of the recombinant adenovirus vector Ad-S100A11 (carrying S100A11) strongly improved cognitive function and induced robust neuroprotective effects after ischemic stroke in vivo. Furthermore, upregulation of S100A11 protected against neuronal apoptosis induced by oxygen-glucose deprivation and reoxygenation (OGD/R) in vitro. Surprisingly, S100A11 overexpression markedly decreased ANXA1 nuclear translocation and subsequently alleviated OGD/R-induced neuronal apoptosis. Notably, S100A11 exerted its neuroprotective effect by directly binding ANXA1. Importantly, S100A11 directly interacted with ANXA1 through the nuclear translocation signal (NTS) of ANXA1, which is essential for ANXA1 to import into the nucleus. Consistent with our previous studies, ANXA1 nuclear translocation after OGD/R promoted p53 transcriptional activity, induced mRNA expression of the pro-apoptotic Bid gene, and activated the caspase-3 apoptotic pathway, which was almost completely reversed by S100A11 overexpression. Thus, S100A11 protects against cell apoptosis by inhibiting OGD/R-induced ANXA1 nuclear translocation. This study provides a novel mechanism whereby S100A11 protects against neuronal cells apoptosis, suggesting the potential for a previously unidentified treatment strategy in minimizing apoptosis after ischemic stroke.

S100A11 promotes TGF-β1-induced epithelial-mesenchymal transition through SMAD2/3 signaling pathway in intrahepatic cholangiocarcinoma

AIM

Our previous study found S100A11 was significantly raised in intrahepatic cholangiocarcinoma cells, but the relationship between S100A11 and intrahepatic cholangiocarcinoma remains unclear.

METHODS

We investigated the effect of silencing S100A11 on TGF-β1-induced epithelial-mesenchymal transition (EMT), cell migration and invasion.

RESULTS

Our results demonstrated silencing S100A11 inhibited TGF-β1-induced cell migration, invasion and EMT, expression of EMT markers E-cadherin, N-cadherin, β-catenin, vimentin, Slug and Snail was reversed. Furthermore, TGF-β1-induced p-SMAD2 and 3 were also inhibited due to low S100A11 expression.

CONCLUSION

Our present study indicated that S100A11 promotes EMT through accumulation of TGF-β1 expression, and TGF-β1-induced upregulation of p-SMAD2 and 3.

S100A11 regulates renal carcinoma cell proliferation, invasion, and migration via the EGFR/Akt signaling pathway and E-cadherin

S100A11 is a S100 protein family member that contributes to cancer progression. Upregulated in human renal cancer tissues, S100A11 may be a prognostic marker for clear cell renal cell carcinoma, but how it functions in cancer is uncertain. Thus, we studied S100A11 and noted knockdown of S100A11 using short hairpin RNA, which inhibited proliferation, invasion, and migration of renal carcinoma cells as well as increased expression of E-cadherin and decreased expression of epidermal growth factor receptor/Akt in renal carcinoma cells. Therefore, S100A11 may be a key molecular target for treating renal carcinoma.

S100P is associated with proliferation and migration in nasopharyngeal carcinoma

In the present study, the function of S100 calcium binding protein P (S100P) in the C666-1 nasopharyngeal carcinoma (NPC) cell line was examined. The levels of S100P protein in NPC tissues were analyzed using immunohistochemistry, and small interfering RNA silenced S100P expression in C666-1 cells. Subsequently, cell proliferation, colony formation, migration and wound-healing assays were performed in order to assess whether the knockdown of S100P was able to influence the biological behavior of C666-1 cells. The expression levels of the receptor for advanced glycation end products (RAGE) were analyzed using a western blot following the inhibition of S100P. The immunohistochemistry results revealed that S100P was elevated in expression in 45/78 (57.7%) of patients with NPC, as compared with 5/30 (16.7%) of patients with benign inflammation. The S100P protein levels correlated with the rates of proliferation and migration in C666-1 cells. Additionally, reduced S100P expression levels altered a series of intracellular events, including the downregulation of epidermal growth factor receptor, cluster of differentiation (CD) 44, matrix metalloproteinase (MMP) 2 and MMP9 protein expression. In addition, RAGE expression was downregulated in the S100P silenced C666-1 cells, as detected by western blot analysis. These data suggest that S100P is important during the development and progression of nasopharyngeal cancer. Therefore, S100P may provide a novel treatment target for NPC.

LASP1-S100A11 axis promotes colorectal cancer aggressiveness by modulating TGFβ/Smad signaling

LIM and SH3 protein 1(LASP1) can promote colorectal cancer (CRC) progression and metastasis, but the mechanism remains unclear. Here, we show that LASP1 interacts with S100 calcium binding protein A11(S100A11) and enhances its expression in CRC. LASP1-S100A11 axis is essential for TGFβ-mediated epithelial-mesenchymal transition (EMT) and cell aggressive phenotype. Clinically, S100A11 is overexpressed in CRC tissues and localized in both the cytoplasm and the nucleus of CRC cells. Overexpression of S100A11 in cytoplasmic and nuclear subcellular compartments is associated with tumor metastasis and poor prognosis of CRC patients. Introduction of cytoplasmic and nuclear S100A11 promotes aggressive phenotypes of CRC cells in vitro as well as growth and metastasis of CRC xenografts, whereas suppressing S100A11 abrogates these effects. Furthermore, we identify flotillin-1 (FLOT1) and histone H1 as downstream factors for cytoplasmic and nuclear pathway of S100A11, which are required for LASP1-S100A11 axis-mediated EMT and CRC progression. These findings indicate S100A11, combined with LASP1, plays a critical role in promoting CRC metastasis via its subcellular effectors, FLOT1 and histone H1.

Up-Regulation of S100A11 in Lung Adenocarcinoma - Its Potential Relationship with Cancer Progression

We previously reported that patients with lung adenocarcinomas with KRAS gene mutations and strong proliferating activity had poorer outcomes, even in the early stage of the disease. The aim of the present study was to elucidate the potential molecular basis of these highly malignant lung tumors by focusing on S100 proteins (S100A2, S100A7, and S100A11), which are downstream targets of oncogenic KRAS and promoters of tumor progression. The immunohistochemical expression of S100 proteins was examined in 179 primary lung adenocarcinomas, and the potential relationships between their levels and clinicopathologic factors were analyzed. Among the three subtypes, S100A11 levels were significantly higher in adenocarcinomas with KRAS mutations and strong proliferating activity. They were also higher in adenocarcinomas with poorly differentiated tumors. Furthermore, higher levels of S100A11 were associated with shorter disease-free survival. These results suggest that the up-regulation of S100A11 plays a role in tumor progression, particularly in KRAS-mutated lung adenocarcinomas.

Knockdown of S100A11 expression suppresses ovarian cancer cell growth and invasion

As a member of the S100 protein family, S100A11 expression is often upregulated in human cancer tissues. Numerous studies have demonstrated that S100A11 plays an important role in the progression of cancer. However, the function of S100A11 in ovarian cancer remains elusive. In the present study, the expression levels of S100A11 were found to be significantly increased in ovarian cancer cells. Subsequently, the expression of S100A11 in ovarian cancer HO8910 cells was knocked down using short hairpin (sh)RNA in order to investigate the biological effects of S100A11 on the progression of the disease. The results demonstrated that knockdown of S100A11 by shRNA inhibited the proliferation, anchorage-independent growth, invasion and migration of HO8910 cells. In addition, knockdown of S100A11 increased the expression of E-cadherin and decreased the expression of Snail in HO8910 cells. Collectively, these results indicated that S100A11 was able to promote the growth, invasion and migration of ovarian cancer cells. Therefore, S100A11 may serve as a potential molecular target for the diagnosis and treatment of ovarian cancer.

Significance of expression of S100A11 and 14-3-3 proteins in esophageal squamous cell carcinoma

AIM: To determine the correlation between invasion, migration and prognosis of esophageal squamous cell carcinoma (ESCC) and expression of S100A11 and 14-3-3 proteins.

METHODS: Sixty-eight previously untreated patients who underwent surgical excision of ESCC were included. The expression of S100A11 and 14-3-3 proteins was examined immunohistochemically in formalin-fixed paraffin-embedded primary tissue specimens. The relationships between the expression of S100A11 and 14-3-3 proteins, the clinicopathologic features of ESCC, and the survival rate of ESCC patients were analyzed. The correlation between S100A11 and 14-3-3 protein expression in ESCC was also analyzed.

RESULTS: The positive rates of S100A11 and 14-3-3 protein expression were significantly higher in ESCC than in normal esophageal tissues (55.9% vs 25.0%, 69.1% vs 33.3%, P < 0.05). S100A11 expression showed no significant correlation with gender, age, ethnicity, tumor size or infiltration depth (P > 0.05), but was significantly correlated with degree of differentiation, lymph node metastasis and clinical stage (P < 0.05). 14-3-3 expression showed no significant correlation with gender, age, ethnicity, or tumor size (P > 0.05), but was significantly correlated with degree of differentiation, depth of infiltration, lymph node metastasis and clinical stage (P < 0.05).

CONCLUSION: S100A11 and 14-3-3 may play a role in the occurrence and development of ESCC. The expression of S100A11 and14-3-3 is significantly related to tumor differentiation, lymph node metastasis and clinical stage, and they may be used to assess the malignant degree of ESCC.