Regulation of S100A2 expression by TGF-β-induced MEK/ERK signalling and its role in cell migration/invasion

Diterpene glycosides from Fructus Rubi ameliorates benign prostatic hyperplasia in rats through the androgen and TGF-β/Smad signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Fructus Rubi (FR), a food material with medicinal value, is used in traditional Chinese medicine (TCM) for treatment of various kidney-related problems, such as impotence, spermatorrhea, and frequent urination. It is also frequently used to produce diverse functional foods in China.

AIM OF STUDY

The purpose of this research was to assess the therapeutic effects of FR diterpene glycosides on RWPE-1 epithelial cell (RWPE-1), a human normal prostatic epithelial cell, and benign prostate hyperplasia (BPH) rats, both of which had been exposed to dihydrotestosterone (DHT) and testosterone propionate (TP), respectively, and to investigate the mechanism of action.

METHODS

Target proteins that could stably bind to certain diterpene glycosides were screened through drug affinity responsive target stability combined with mass spectrometry (DARTS/MS). DHT-induced RWPE-1 cells were used to detect drug activity. TP was subcutaneously injected to induce BPH in rats. The extract of diterpene glycosides from FR (FDS) was orally administered for 28 days. The DHT levels in the serum and prostate tissue of the rats were measured through enzyme-linked immunosorbent assay (ELISA), and to analyze cell proliferation and epithelial-mesenchymal transition (EMT), the protein expression of prostate-specific antigen (PSA), androgen receptor (AR), steroid 5α-reductase type 2 (SRD5A2), proliferating cell nuclear antigen (PCNA), S100 calcium-binding protein A2 (S100A2), transforming growth factor-β1 (TGF-β1), E-cadherin, vimentin, and Smad4 was determined through western blotting (WB), immunohistochemistry (IHC), or immunofluorescence (IF).

RESULTS

FDS reduced the proliferation of DHT-induced RWPE-1 cells. It also significantly inhibited rat prostate enlargement; decreased DHT levels in the serum and prostate tissue; inhibited the protein expression of AR, PSA, PCNA, S100A2, TGF-β1, E-cadherin, and Smad4; and increased the protein expression of E-cadherin.

CONCLUSION

The present study is the first to report that diterpene glycosides isolated from FR inhibited BPH at the cellular level, regulated the proliferation of prostate cells through the androgen signaling pathway, and prevented EMT in the prostate through the S100A2-mediated TGF-β/Smad signaling pathway. These results indicate that FDS is a promising multitarget therapy for BPH.

S100 Proteins in the Pathogenesis of Psoriasis and Atopic Dermatitis

The skin, the outermost layer of the human body, is exposed to various external stimuli that cause inflammatory skin reactions. These external stimulants trigger external epithelial cell damage and the release of intracellular substances. Following cellular damage or death, intracellular molecules are released that enhance tissue inflammation. As an important substance released from damaged cells, the S100 protein is a low-molecular-weight acidic protein with two calcium-binding sites and EF-hand motif domains. S100 proteins are widely present in systemic organs and interact with other proteins. Recent studies revealed the involvement of S100 in cutaneous inflammatory disorders, psoriasis, and atopic dermatitis. This review provides detailed information on the interactions among various S100 proteins in inflammatory diseases.

S100A2 induces epithelial-mesenchymal transition and metastasis in pancreatic cancer by coordinating transforming growth factor β signaling in SMAD4-dependent manner

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive tumor and is associated with a poor prognosis. Treatment strategies for PDAC are largely ineffective primarily because of delay in its diagnosis and limited efficacy of systematic treatment. S100A2 is associated with the proliferation, migration, and differentiation of several tumors; however, its effects on PDAC and the associated molecular mechanisms remain to be explored. We studied the mechanisms underlying the effect of S100A2 on epithelial-mesenchymal transition (EMT) and metastasis in PDAC cells. We found that the level of S100A2 remarkably increased and was associated with poor PDAC prognosis. The overexpression of S100A2 in PANC-1 cells also induced EMT, in addition to increasing the invasion and migration of PDAC cells, whereas the knockdown of S100A2 markedly inhibited cell metastasis. Furthermore, S100A2 was found to enhance metastatic abilities in vivo. The overexpression of S100A2 increased SMAD4 expression, whereas the knockdown of S100A2 reduced SMAD4 expression. SMAD4 overexpression could effectively rescue the effects of S100A2 knockdown on EMT. S100A2 mechanistically activated the transforming growth factor (TGF)-β/Smad2/3 signaling pathway, upregulated SMAD4 expression, induced EMT, and increased PANC-1 cell metastasis. In conclusion, the S100A2/SMAD4 axis modulates EMT to accelerate PDAC development. Our results supplement and enrich the understanding of the pathogenesis underlying PDAC and provide a new theoretical basis and strategy targeting S100A2 for the diagnosis and treatment of PDAC.

Pathogenic role of S100 proteins in psoriasis

Psoriasis is a chronic inflammatory skin disease. The histopathological features of psoriasis include excessive proliferation of keratinocytes and infiltration of immune cells. The S100 proteins are a group of EF-hand Ca2+-binding proteins, including S100A2, -A7, -A8/A9, -A12, -A15, which expression levels are markedly upregulated in psoriatic skin. These proteins exert numerous functions such as serving as intracellular Ca2+ sensors, transduction of Ca2+ signaling, response to extracellular stimuli, energy metabolism, and regulating cell proliferation and apoptosis. Evidence shows a crucial role of S100 proteins in the development and progress of inflammatory diseases, including psoriasis. S100 proteins can possibly be used as potential therapeutic target and diagnostic biomarkers. This review focuses on the pathogenic role of S100 proteins in psoriasis.

Influence of S100A2 in Human Diseases

S100 proteins are a family of low-molecular-weight proteins characterized by two calcium-binding sites with a helix-loop-helix (“EF-hand-type”) domain. The S100 family of proteins is distributed across various organs and can interact with diverse molecules. Among the proteins of the S100 family, S100 calcium-binding protein A2 (S100A2) has been identified in mammary epithelial cells, glands, lungs, kidneys, and prostate gland, exhibiting various physiological and pathological actions in human disorders, such as inflammatory diseases and malignant tumors. In this review, we introduce basic knowledge regarding S100A2 regulatory mechanisms. Although S100A2 is a tumor suppressor, we describe the various influences of S100A2 on cancer and inflammatory diseases.

Transcriptional activation of S100A2 expression by HIF-1α via binding to the hypomethylated hypoxia response elements in HCC cells

Hepatocellular carcinoma (HCC) is one of the most prevalent and lethal cancers. Dysregulation of S100A2 has recently been found in many cancers including HCC. However, its regulatory mechanism in HCC remains poorly understood, especially in hypoxia. In this study, we found that S100A2 is upregulated and correlated with the clinicopathological features of HCC patients. Moreover, the elevated S100A2 showed worse overall survival. Functionally, S100A2 inhibition decreased the proliferation and migration of HepG2 cells. Interestingly, we found that HIF-1α directly binds to hypoxia response elements (HREs) of the S100A2 promoter region. S100A2 expression could be induced in an HIF-1α-dependent manner under hypoxia. Furthermore, S100A2 silencing significantly suppressed HCC cell proliferation and invasion under hypoxia. Mechanistically, pyrosequencing results showed that the hypomethylation status of CpG located in the HRE at the S100A2 promoter was correlated with S100A2 induction. Additionally, HIF-1α- mediated S100A2 activation was associated with TET2-related epigenetic inactivation. TET2 was enriched in the HRE of the S100A2 promoter in HepG2 cells. Finally, S100A2 methylation-related genes and pathways were analyzed. We found that the methylation of S100A2 is correlated with ANXA2, PPP1R15A, and FOS, which include in a hypoxia-related gene set from the GSEA database. Moreover, some EMT-related genes are associated with the methylation of S100A2 in HCC. Conclusively, our study thus uncovered a novel mechanism showing that hypoxia/HIF-1α signaling associated with DNA methylation enhances S100A2 expression in HCC. S100A2 may be useful as a target for facilitating novel diagnostic and therapeutic strategies in liver cancer.

Genetic Variants of CLEC4E and BIRC3 in Damage-Associated Molecular Patterns-Related Pathway Genes Predict Non-Small Cell Lung Cancer Survival

Accumulating evidence supports a role of various damage-associated molecular patterns (DAMPs) in progression of lung cancer, but roles of genetic variants of the DAMPs-related pathway genes in lung cancer survival remain unknown. We investigated associations of 18,588 single-nucleotide polymorphisms (SNPs) in 195 DAMPs-related pathway genes with non-small cell lung cancer (NSCLC) survival in a subset of genotyping data for 1,185 patients from the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial and validated the findings in another independent subset of genotyping data for 984 patients from Harvard Lung Cancer Susceptibility Study. We performed multivariate Cox proportional hazards regression analysis, followed by expression quantitative trait loci (eQTL) analysis, Kaplan-Meier survival analysis and bioinformatics functional prediction. We identified that two SNPs (i.e., CLEC4E rs10841847 G>A and BIRC3 rs11225211 G>A) were independently associated with NSCLC overall survival, with adjusted allelic hazards ratios of 0.89 (95% confidence interval=0.82-0.95 and P=0.001) and 0.82 (0.73-0.91 and P=0.0003), respectively; so were their combined predictive alleles from discovery and replication datasets (P_trend=0.0002 for overall survival). We also found that the CLEC4E rs10841847 A allele was associated with elevated mRNA expression levels in normal lymphoblastoid cells and whole blood cells, while the BIRC3 rs11225211 A allele was associated with increased mRNA expression levels in normal lung tissues. Collectively, these findings indicated that genetic variants of CLEC4E and BIRC3 in the DAMPs-related pathway genes were associated with NSCLC survival, likely by regulating the mRNA expression of the corresponding genes.

Knockdown of ferritin heavy chain (FTH) inhibits the migration of prostate cancer through reducing S100A4, S100A2, and S100P expression

BACKGROUND

Ferritin plays a key role in the development of prostate cancer (PCa). Our earlier studies showed that the knockdown of ferritin heavy chain (FTH) suppressed the migration and invasion of the prostate cancer cell line (PC3). However, the mechanisms behind FTH in the cell migration regulation of PCa have not been thoroughly investigated.

METHODS

Isobaric tags for relative and absolute quantitation (iTRAQ) proteomics was used to analyze the protein expression in PC3 cells with FTH knockdown by small interfering RNAs and negative control cells. We subsequently ranked the differentially expressed proteins according to the change in expression. We further performed Gene Ontology (GO) analysis for the changing-expression protein. Finally, Western blot analysis was performed to determine the expression of the target protein.

RESULTS

Compared with the negative group, 420 proteins were downregulated, including proteins S100A4, S100P, and S100A2, while the expression of 442 protein was elevated in FTH-silencing PC3 cells (P<0.05, fold change >1.2). The mass spectrometry results showing decreased expression of protein S100A4, S100P, and S100A2 in the cells were further validated by Western blot (P<0.05). Levels of protein S100A4, S100A2, and S100P were reduced in FTH-silencing PC3 cells (P<0.05, fold change >1.6).

CONCLUSIONS

The downregulation of FTH expression reduced the level of protein S100A4, S100A2, and S100P, which all play a key role in the migration and invasion of tumor cells. Therefore, it is reasonable to assume that there are correlations between the expression of the S100A4, S100A2, and S100P genes with FTH. Based on this research, FTH may be a new biomarker for the diagnosis of PCa.

Exploring the wound healing, anti-inflammatory, anti-pathogenic and proteomic effects of lactic acid bacteria on keratinocytes

The topical application of lactic acid bacteria (LAB) is recognized as a useful approach to improve skin health. This work aims to characterize by a multidisciplinary approach, the wound healing, anti-inflammatory, anti-pathogens and proteomic effects of six LAB lysates, belonging to the genus Lactobacillus. Our results demonstrated that the lysates of tested LAB stimulated the proliferation of keratinocytes, and that L. plantarum SGL 07 and L. salivarius SGL 19 accelerated the re-epithelization by inducing keratinocyte migration. The bacterial lysates also reduced the secretion of specific pro-inflammatory mediators from keratinocytes. Furthermore, viable L. salivarius SGL 19 and L. fermentum SGL 10 had anti-pathogenic effects against S. aureus and S. pyogenes, while L. brevis SGL 12 and L. paracasei SGL 04 inhibited S. aureus and S. pyogenes, respectively. The tested lactobacilli lysates also induced specific proteome modulation of the exposed keratinocytes, involving dysregulation of proteins (such as interleukin enhancer-binding factor 2 and ATP-dependent RNA helicase) and pathways (such as cytokine, NF-kB, Hedgehog, and RUNX signaling) associated with their specific wound healing and anti-inflammatory effects. This study indicates the different potential of selected lactobacilli, suggesting that they may be successfully used in the future together with conventional therapies to bring relief from skin disorders.

An Update to Calcium Binding Proteins

Ca²⁺ binding proteins (CBP) are of key importance for calcium to play its role as a pivotal second messenger. CBP bind Ca²⁺ in specific domains, contributing to the regulation of its concentration at the cytosol and intracellular stores. They also participate in numerous cellular functions by acting as Ca²⁺ transporters across cell membranes or as Ca²⁺-modulated sensors, i.e. decoding Ca²⁺ signals. Since CBP are integral to normal physiological processes, possible roles for them in a variety of diseases has attracted growing interest in recent years. In addition, research on CBP has been reinforced with advances in the structural characterization of new CBP family members. In this chapter we have updated a previous review on CBP, covering in more depth potential participation in physiopathological processes and candidacy for pharmacological targets in many diseases. We review intracellular CBP that contain the structural EF-hand domain: parvalbumin, calmodulin, S100 proteins, calcineurin and neuronal Ca²⁺ sensor proteins (NCS). We also address intracellular CBP lacking the EF-hand domain: annexins, CBP within intracellular Ca²⁺ stores (paying special attention to calreticulin and calsequestrin), proteins that contain a C2 domain (such as protein kinase C (PKC) or synaptotagmin) and other proteins of interest, such as regucalcin or proprotein convertase subtisilin kexins (PCSK). Finally, we summarise the latest findings on extracellular CBP, classified according to their Ca²⁺ binding structures: (i) EF-hand domains; (ii) EGF-like domains; (iii) ɣ-carboxyl glutamic acid (GLA)-rich domains; (iv) cadherin domains; (v) Ca²⁺-dependent (C)-type lectin-like domains; (vi) Ca²⁺-binding pockets of family C G-protein-coupled receptors.

Prognostic Roles of mRNA Expression of S100 in Non-Small-Cell Lung Cancer

The S100 protein family is involved in cancer cell invasion and metastasis, but its prognostic value in non-small-cell lung cancer (NSCLC) has not been elucidated. In the present study we investigated the prognostic role of mRNA expression of each individual S100 in NSCLC patients through the Kaplan-Meier plotter (KM plotter) database. Expression of 14 members of the S100 family correlated with overall survival (OS) for all NSCLC patients; 18 members were associated with OS in adenocarcinoma, but none were associated with OS in squamous cell carcinoma. In particular, high mRNA expression level of S100B was associated with better OS in NSCLC patients. The prognostic value of S100 according to smoking status, pathological grades, clinical stages, and chemotherapeutic treatment of NSCLC was further assessed. Although the results should be further verified in clinical trials our findings provide new insights into the prognostic roles of S100 proteins in NSCLC and might promote development of S100-targeted inhibitors for the treatment of NSCLC.

A review of S100 protein family in lung cancer

S100 protein family, representing 25 relatively small calcium binding proteins, has been reported to be involved in multiple stages of tumorigenesis and progression. These proteins are considered having potential value to be adopted as novel biomarkers in the detection and accurate prediction of many kinds of tumors, including lung cancer. As the one having the highest morbidity and mortality among all cancers, lung carcinoma is still occult for detection, especially at early stage. S100 proteins take participation in the lung neoplasia through playing intracellular and/or extracellular functions, therefore getting involved in a variety of biological processes such as differentiation, proliferation, and migration. A few members have also been testified to modulate TGF-β/Smad-3 mediated transcriptional activity of target genes involved in tumor promotion. In addition to that, a number of proteins in this family have already been reported to experience an abnormal trend in lung cancer at cell, serum and tissue levels. Thus, S100 proteins may serve as effective biomarkers for suspected or already diagnosed lung cancer patients. In future, S100 protein family might be applied as therapeutic targets in clinical treatment of lung cancer. In this review, we firstly summed up the biological and clinical evidence connecting S100 proteins and lung cancer, which has not been summarized before.

Blocking ERK1/2 signaling impairs TGF-β1 tumor promoting function but enhances its tumor suppressing role in intrahepatic cholangiocarcinoma cells

Background

Transforming growth factor-β (TGF-β) plays a paradoxical role in cancer: it suppresses proliferation at early stages but promotes metastasis at late stages. This cytokine is upregulated in cholangiocarcinoma and is implicated in cholangiocarcinoma invasion and metastasis. Here we investigated the roles of non-Smad pathway (ERK1/2) and Smad in TGF-β tumor promoting and suppressing activities in intrahepatic cholangiocarcinoma (ICC) cells.

Methods

TGF-β1 effects on proliferation, invasion and migration of ICC cells, KKU-M213 and/or HuCCA-1, were investigated using MTT, colony formation, in vitro Transwell and wound healing assays. Levels of mRNAs and proteins/phospho-proteins were measured by quantitative (q)RT-PCR and Western blotting respectively. E-cadherin localization was examined by immunofluorescence and secreted MMP-9 activity was assayed by gelatin zymography. The role of ERK1/2 signaling was evaluated by treating cells with TGF-β1 in combination with MEK1/2 inhibitor U0126, and that of Smad2/3 and Slug using siSmad2/3- and siSlug-transfected cells.

Results

h-TGF-β1 enhanced KKU-M213 cell invasion and migration and induced epithelial-mesenchymal transition as shown by an increase in vimentin, Slug and secreted MMP-9 levels and by a change in E-cadherin localization from membrane to cytosol, while retaining the cytokine’s ability to attenuate cell proliferation. h-TGF-β1 stimulated Smad2/3 and ERK1/2 phosphorylation, and the MEK1/2 inhibitor U0126 attenuated TGF-β1-induced KKU-M213 cell invasion and MMP-9 production but moderately enhanced the cytokine growth inhibitory activity. The latter effect was more noticeable in HuCCA-1 cells, which resisted TGF-β-anti-proliferative activity. Smad2/3 knock-down suppressed TGF-β1 ability to induce ERK1/2 phosphorylation, Slug expression and cell invasion, whereas Slug knock-down suppressed cell invasion and vimentin expression but marginally affected ERK1/2 activation and MMP-9 secretion. These results indicate that TGF-β1 activated ERK1/2 through Smad2/3 but not Slug pathway, and that ERK1/2 enhanced TGF-β1 tumor promoting but repressed its tumor suppressing functions.

Conclusions

Inhibiting ERK1/2 activation attenuates TGF-β1 tumor promoting effect (invasion) but retains its tumor suppressing role, thereby highlighting the importance of ERK1/2 in resolving the TGF-β paradox switch.

Electronic supplementary material

The online version of this article (doi:10.1186/s12935-017-0454-2) contains supplementary material, which is available to authorized users.

Expression and clinicopathological significance of S100 calcium binding protein A2 in lung cancer patients of Chinese Han ethnicity

BACKGROUND

S100 family of calcium-binding proteins plays a significant role in the process of many kinds of tumors, including lung cancer. As an important member of this family, S100 calcium binding protein A2 (S100A2) has been confirmed to be associated with many biological processes, and has an abnormal expression in non-small cell lung cancer (NSCLC). However, the S100A2 status in lung cancer is still controversial and undefined.

METHODS

We evaluated the pattern and distribution of S100A2 in 109 cases of lung cancer, including five histological types (47 adenocarcinoma, 46 squamous cell carcinoma, 7 small cell carcinoma, 3 large cell carcinoma, and 6 atypical carcinoid), and 30 cases of paired adjacent normal lung tissues by means of immunohistochemistry.

RESULTS

Compared with the normal tissues (0/30), S100A2 experienced a dramatically upward trend of positive expression in lung cancer, with a positive rate of 68/109 (P<0.001). Specifically, squamous cell carcinoma, with 34/12, had the highest expression ratio, followed by large cell carcinoma (2/1), adenocarcinoma (31/16), and atypical carcinoid (1/5) respectively, while no S100A2 protein was detected in small cell carcinoma. Meanwhile, we firstly demonstrated that the high expression of S100A2 was significantly associated with the incidence of lymph node metastasis in adenocarcinoma (P=0.013).

CONCLUSIONS

The association between high S100A2 expression and NSCLC at the level of tissue, and S100A2 may serve as an effective biomarker for the diagnosis and prognosis of NSCLC in future.

Overexpression of the S100A2 protein as a prognostic marker for patients with stage II and III colorectal cancer

We aimed to identify a novel prognostic biomarker related to recurrence in stage II and III colorectal cancer (CRC) patients. Stage II and III CRC tissue mRNA expression was profiled using an Affymetrix Gene Chip, and copy number profiles of 125 patients were generated using an Affymetrix 250K Sty array. Genes showing both upregulated expression and copy number gains in cases involving recurrence were extracted as candidate biomarkers. The protein expression of the candidate gene was assessed using immunohistochemical staining of tissue from 161 patients. The relationship between protein expression and clinicopathological features was also examined. We identified 9 candidate genes related to recurrence of stage II and III CRC, whose mRNA expression was significantly higher in CRC than in normal tissue. Of these proteins, the S100 calcium-binding protein A2 (S100A2) has been observed in several human cancers. S100A2 protein overexpression in CRC cells was associated with significantly worse overall survival and relapse-free survival, indicating that S100A2 is an independent risk factor for stage II and III CRC recurrence. S100A2 overexpression in cancer cells could be a biomarker of poor prognosis in stage II and III CRC recurrence and a target for treatment of this disease.

Myc coordinates transcription and translation to enhance transformation and suppress invasiveness

c‐Myc is one of the major human proto‐oncogenes and is often associated with tumor aggression and poor clinical outcome. Paradoxically, Myc was also reported as a suppressor of cell motility, invasiveness, and metastasis. Among the direct targets of Myc are many components of the protein synthesis machinery whose induction results in an overall increase in protein synthesis that empowers tumor cell growth. At present, it is largely unknown whether beyond the global enhancement of protein synthesis, Myc activation results in translation modulation of specific genes. Here, we measured Myc‐induced global changes in gene expression at the transcription, translation, and protein levels and uncovered extensive transcript‐specific regulation of protein translation. Particularly, we detected a broad coordination between regulation of transcription and translation upon modulation of Myc activity and showed the connection of these responses to mTOR signaling to enhance oncogenic transformation and to the TGFβ pathway to modulate cell migration and invasiveness. Our results elucidate novel facets of Myc‐induced cellular responses and provide a more comprehensive view of the consequences of its activation in cancer cells.

The S100 proteins in epidermis: Topology and function

BACKGROUND

S100 proteins are small calcium binding proteins encoded by genes located in the epidermal differentiation complex (EDC). Differently to other proteins encoded by EDC genes, which are indispensable for normal epidermal differentiation, the role of S100 proteins in the epidermis remains largely unknown.

SCOPE OF REVIEW

Particular S100 proteins differ in their distribution in epidermal layers, skin appendages, melanocytes and Langerhans cells. Taking into account that each epidermal component consists of specialized cells with well-defined functions, such differential distribution may be indicative of the function of a given S100 protein. We used this criterion together with the survey of the current experimental data pertinent to epidermis to provide a fairly comprehensive view on the possible function of individual S100 proteins in this tissue.

MAJOR CONCLUSIONS

S100 proteins are differently expressed and, despite extensive structural homology, perform diverse functions in the epidermis. Certain S100 proteins probably ensure constant epidermal renewal and support wound healing while others act in epidermal differentiation or have a protective role. As their expression is differently affected in various skin pathologies, particular S100 proteins could be valuable diagnostic markers.

GENERAL SIGNIFICANCE

S100 proteins seem to be important although not yet fully recognized epidermal constituents. Better understanding of their role in the epidermis might be helpful in designing therapies to various skin diseases.

A phase II evaluation of selumetinib (AZD6244, ARRY-142886), a selective MEK-1/2 inhibitor in the treatment of recurrent or persistent endometrial cancer: an NRG Oncology/Gynecologic Oncology Group study

BACKGROUND

Activation of the mitogen activated protein kinase pathway plays a pivotal role in cell proliferation and is frequently activated in endometrial cancer. We sought to evaluate the efficacy/safety of selumetinib, a selective MEK-1/2 inhibitor in women with recurrent endometrial cancer.

METHODS

This was a phase II, single-arm, open-label study evaluating response and 6-month event-free survival (EFS) as primary endpoints. Eligible patients had measurable disease, 1-2 prior cytotoxic regimens, and performance status 0-2. Selumetinib 75mg PO BID was administered daily until progression or intolerance. One cycle was 28days.

RESULTS

Fifty-four patients were enrolled; 2 were excluded due to improper pre-study treatment (1) and never treated (1), leaving 52 evaluable for efficacy/safety. Median age was 62; histology included endometrioid (58%), serous (17%) and mixed (23%). Seventeen patients (33%) had 2 prior cytotoxic regimens. The median number of cycles administered was 2 (1-34). Three (6%) patients had objective response (1 CR, 2 PR); 13 had SD as best response. The proportion of patients with 6-month EFS was 12%. Median EFS, progression-free and overall survival was 2.1, 2.3, and 8.5months, respectively. Drug-attributed grade 3/4 adverse events were observed (≥5%) were fatigue (15%), anemia (10%), pain (10%), extremity edema (8%), and dyspnea (6%). There was 1 grade 4 infection (renal), 1 grade 4 anemia, and 1 death due to hemorrhage (rectum).

CONCLUSIONS

Selumetinib was tolerable in this population but did not meet pre-trial specifications for clinical efficacy.

Comparative Proteomic Analysis of Human Cholangiocarcinoma Cell Lines: S100A2 as a Potential Candidate Protein Inducer of Invasion

Cholangiocarcinoma (CCA) is a bile duct cancer, commonly found in Asia including Thailand and especially in the northeastern region of Thailand. To identify the proteins involved in carcinogenesis and metastasis of CCA, protein expression profiles of high-invasive KKU-M213 and low-invasive KKU-100 cell lines were compared using a comparative GeLC-MS/MS proteomics analysis. A total of 651 differentially expressed proteins were detected of which 27 protein candidates were identified as having functions involved in cell motility. A total of 22 proteins were significantly upregulated in KKU-M213, whereas 5 proteins were downregulated in KKU-M213. S100A2, a calcium-binding protein in S100 protein family, is upregulated in KKU-M213. S100A2 is implicated in metastasis development in several cancers. The protein expression level of S100A2 was verified by Western blot analysis. Intriguingly, high-invasive KKU-M213 cells showed higher expression of S100A2 than KKU-100 cells, consistent with proteomic data, suggesting that S100A2 may be a key protein involved in the progression of CCA. However, the biological function of S100A2 in cholangiocarcinoma remains to be elucidated. S100A2 might be a potential biomarker as well as a novel therapeutic target in CCA metastasis.

Context dependent non canonical WNT signaling mediates activation of fibroblasts by transforming growth factor-β

Actions of transforming growth factor-β are largely context dependent. For instance, TGF-β is growth inhibitory to epithelial cells and many tumor cell-lines while it stimulates the growth of mesenchymal cells. TGF-β also activates fibroblast cells to a myofibroblastic phenotype. In order to understand how the responsiveness of fibroblasts to TGF-β would change in the context of transformation, we have compared the differential gene regulation by TGF-β in immortal fibroblasts (hFhTERT), transformed fibroblasts (hFhTERT-LTgRAS) and a human fibrosarcoma cell-line (HT1080). The analysis revealed regulation of 6735, 4163, and 3478 probe-sets by TGF-β in hFhTERT, hFhTERT-LTgRAS and HT1080 cells respectively. Intriguingly, 5291 probe-sets were found to be either regulated in hFhTERT or hFhTERT-LTgRAS cells while 2274 probe-sets were regulated either in hFhTERT or HT1080 cells suggesting that the response of immortal hFhTERT cells to TGF-β is vastly different compared to the response of both the transformed cells hFhTERT-LTgRAS and HT1080 to TGF-β. Strikingly, WNT pathway showed enrichment in the hFhTERT cells in Gene Set Enrichment Analysis. Functional studies showed induction of WNT4 by TGF-β in hFhTERT cells and TGF-β conferred action of these cells was mediated by WNT4. While TGF-β activated both canonical and non-canonical WNT pathways in hFhTERT cells, Erk1/2 and p38 Mitogen Activated Protein Kinase pathways were activated in hFhTERT-LTgRAS and HT1080 cells. This suggests that transformation of immortal hFhTERT cells by SV40 large T antigen and activated RAS caused a switch in their response to TGF-β which matched with the response of HT1080 cells to TGF-β. These data suggest context dependent activation of non-canonical signaling by TGF-β.

Enhanced FHL2 and TGF-β1 Expression Is Associated With Invasive Growth and Poor Survival in Malignant Melanomas

OBJECTIVES

This study examines the expression and the role of four-and-a-half LIM domains protein 2 (FHL2) and transforming growth factor β1 (TGF-β1) in human malignant melanoma. It is determined whether both proteins influence melanoma survival time.

METHODS

We analyzed the immunohistochemical staining intensities of FHL2 and TGF-β1 in normal skin and in 50 malignant melanomas with different mutation status (BRAF-V600E, NRAS codon 61 mutation, and wild type). Survival data were available for 45 cases.

RESULTS

In melanocytes of nonneoplastic human skin, FHL2 expression was absent. In contrast, 38 (76%) of 50 melanomas showed strong cytoplasmic and partly nuclear FHL2 expression. At the invasion front, cytoplasmic TGF-β1 staining was observed in 32 (64%) of 50 melanomas, and a correlation of FHL2 and TGF-β1 staining intensities was detectable. In follow-up analyses, enhanced FHL2 and TGF-β1 staining intensities in the tumor invasion front were associated with poor survival.

CONCLUSIONS

Enhanced FHL2 and TGF-β1 expression is correlated with poor survival in human malignant melanoma. Protumorigenic effects of autocrine TGF-β1 secretion might be exerted by induction of FHL2 expression in melanoma cells. Since melanomas treated with targeted therapies often do not show sufficient response rates, inhibition of FHL2 and/or TGF-β1 might be a promising therapeutic approach.

Prognostic significance of cytoplasmic S100A2 overexpression in oral cancer patients

Background

Oral squamous cell carcinoma (OSCC) patients are at high risk of loco-regional recurrence and 5-year survival rates are about 50%. Identification of patients at high risk of recurrence will enable rigorous personalized post-treatment management. Most novel biomarkers have failed translation for clinical use because of their limited successful validation in external patient cohorts. The aim of this study was to determine the prognostic significance of alterations in sub-cellular expression of S100A2, a pro-tumorigenic calcium binding protein, identified as a candidate biomarker in our proteomic analysis in OSCC and validation of its clinical utility in an external cohort.

Methods

In a retrospective study, immunohistochemical analysis of S100A2 was carried out in 235 Indian OSCC (Test set) and 129 normal oral tissues, correlated with clinicopathological parameters and disease outcome over 122 months for OSCC patients following the REMARK criteria. The findings were validated in an external cohort (Validation set 115 Canadian OSCC and 51 normal tissues) and data analyzed using the R package.

Results

Significant increase in cytoplasmic and decrease in nuclear S100A2 expression was observed in OSCC in comparison with normal tissues. Cox multivariable regression analysis internally and externally validated cytoplasmic S100A2 association with tumor recurrence. Kaplan Meier analysis of patients stratified to high and low risk groups showed significantly different recurrence free survival (Test set- log rank test, p = 0.005, median survival 16 and 69 months respectively and Validation set - p < 0.00001, median survival 9.4 and 59.9 months respectively); 86% and 81% of patients who had recurrence were correctly stratified into the high risk group. Seventy percent and 81% patients stratified into low risk group did not show cancer recurrence within 1 year in Test and Validation sets.

Conclusions

Our study provided clinical evidence for the potential of cytoplasmic S100A2 overexpression as a predictor of recurrence risk in OSCC patients. A unique translational aspect of our study is validation of S100A2 as prognostic marker in two independent cohorts (Canadian and Indian) suggesting this protein is likely to find widespread utility in clinical practice for identifying oral cancer patients at high risk of disease recurrence.

The antimicrobial peptides psoriasin (S100A7) and koebnerisin (S100A15) suppress extracellular matrix production and proliferation of human fibroblasts

BACKGROUND/AIMS

Keloids result from aberrations in the normal wound healing cascade and can lead to pruritus, contractures and pain. The underlying mechanisms of excessive scarring are not yet understood, and most therapeutic strategies remain unsatisfactory. Psoriasin (S100A7) and koebnerisin (S100A15) are released by keratinocytes during physiological wound healing. We found S100 production is markedly decreased in keloid scar tissue. The disturbed epidermal S100 expression might contribute to keloid formation; thus, we studied their effect on dermal fibroblasts and extracellular matrix (ECM) production.

METHODS

S100 peptides, ECM regulation and distribution were analysed in normal and keloid tissue by quantitative PCR (qPCR), immunoblotting and immunofluorescent staining. Isolated dermal fibroblasts were incubated with S100 proteins, and the regulation of ECM and transforming growth factor (TGF)-β was determined using qPCR. Fibroblast proliferation and viability were determined by the 5-bromo-2'-deoxyuridine assay and crystal violet assay.

RESULTS

Keloid tissue featured a pronounced expression of ECMs, such as collagen types 1 and 3, whereas the production of psoriasin and koebnerisin was markedly decreased in keloid-derived cells and keloid tissue. Both S100 proteins inhibited the expression of collagens, fibronectin-1, α-smooth-muscle actin and TGF-β by fibroblasts. Further, they also suppressed fibroblast proliferation.

CONCLUSION

Psoriasin and koebnerisin show antifibrotic effects and may lead to novel preventive and therapeutic strategies for fibroproliferative diseases.

Proteomics-Based Identification of Differentially Abundant Proteins from Human Keratinocytes Exposed to Arsenic Trioxide

INTRODUCTION

Arsenic is a widely distributed environmental toxicant that can cause multi-tissue pathologies. Proteomic assays allow for the identification of biological processes modulated by arsenic in diverse tissue types.

METHOD

The altered abundance of proteins from HaCaT human keratinocyte cell line exposed to arsenic was quantified using a label-free LC-MS/MS mass spectrometry workflow. Selected proteomics results were validated using western blot and RT-PCR. A functional annotation analytics strategy that included visual analytical integration of heterogeneous data sets was developed to elucidate functional categories. The annotations integrated were mainly tissue localization, biological process and gene family.

RESULT

The abundance of 173 proteins was altered in keratinocytes exposed to arsenic; in which 96 proteins had increased abundance while 77 proteins had decreased abundance. These proteins were also classified into 69 Gene Ontology biological process terms. The increased abundance of transferrin receptor protein (TFRC) was validated and also annotated to participate in response to hypoxia. A total of 33 proteins (11 increased abundance and 22 decreased abundance) were associated with 18 metabolic process terms. The Glutamate--cysteine ligase catalytic subunit (GCLC), the only protein annotated with the term sulfur amino acid metabolism process, had increased abundance while succinate dehydrogenase [ubiquinone] iron-sulfur subunit, mitochondrial precursor (SDHB), a tumor suppressor, had decreased abundance.

CONCLUSION

A list of 173 differentially abundant proteins in response to arsenic trioxide was grouped using three major functional annotations covering tissue localization, biological process and protein families. A possible explanation for hyperpigmentation pathologies observed in arsenic toxicity is that arsenic exposure leads to increased iron uptake in the normally hypoxic human skin. The proteins mapped to metabolic process terms and differentially abundant are candidates for evaluating metabolic pathways perturbed by arsenicals.

Pathway landscapes and epigenetic regulation in breast cancer and melanoma cell lines

BACKGROUND

Epigenetic variation is a main regulation mechanism of gene expression in various cancer histotypes, and due to its reversibility, the potential impact in therapy can be very relevant.

METHODS

Based on a selected pair, breast cancer (BC) and melanoma, we conducted inference analysis in parallel on a few cell lines (MCF-7 for BC and A375 for melanoma). Starting from differential expression after treatment with a demethylating agent, the 5-Aza-2'-deoxycytidine (DAC), we provided pathway enrichment analysis and gene regulatory maps with cross-linked microRNAs and transcription factors.

RESULTS

Several oncogenic signaling pathways altered upon DAC treatment were detected with significant enrichment. We represented the association between these cancers by depicting the landscape of common and specific variation affecting them.

Joining S100 proteins and migration: for better or for worse, in sickness and in health

The vast diversity of S100 proteins has demonstrated a multitude of biological correlations with cell growth, cell differentiation and cell survival in numerous physiological and pathological conditions in all cells of the body. This review summarises some of the reported regulatory functions of S100 proteins (namely S100A1, S100A2, S100A4, S100A6, S100A7, S100A8/S100A9, S100A10, S100A11, S100A12, S100B and S100P) on cellular migration and invasion, established in both culture and animal model systems and the possible mechanisms that have been proposed to be responsible. These mechanisms involve intracellular events and components of the cytoskeletal organisation (actin/myosin filaments, intermediate filaments and microtubules) as well as extracellular signalling at different cell surface receptors (RAGE and integrins). Finally, we shall attempt to demonstrate how aberrant expression of the S100 proteins may lead to pathological events and human disorders and furthermore provide a rationale to possibly explain why the expression of some of the S100 proteins (mainly S100A4 and S100P) has led to conflicting results on motility, depending on the cells used.

Influence of energy balance on the antimicrobial peptides S100A8 and S100A9 in the endometrium of the post-partum dairy cow

Uterine inflammation occurs after calving in association with extensive endometrial remodelling and bacterial contamination. If the inflammation persists, it leads to reduced fertility. Chronic endometritis is highly prevalent in high-yielding cows that experience negative energy balance (NEB) in early lactation. This study investigated the effect of NEB on the antimicrobial peptides S100A8 and S100A9 in involuting uteri collected 2 weeks post partum. Holstein-Friesian cows (six per treatment) were randomly allocated to two interventions designed to produce mild or severe NEB (MNEB and SNEB) status. Endometrial samples were examined histologically, and the presence of neutrophils, macrophages, lymphocytes and natural killer cells was confirmed using haematoxylin and eosin and immunostaining. SNEB cows had greater signs of uterine inflammation. Samples of previously gravid uterine horn were used to localise S100A8 and S100A9 by immunohistochemistry. Both S100 proteins were present in bovine endometrium with strong staining in epithelial and stromal cells and in infiltrated leucocytes. Immunostaining was significantly higher in SNEB cows along with increased numbers of segmented neutrophils. These results suggest that the metabolic changes of a post-partum cow suffering from NEB delay uterine involution and promote a chronic state of inflammation. We show that upregulation of S100A8 and S100A9 is clearly a key component of the early endometrial response to uterine infection. Further studies are warranted to link the extent of this response after calving to the likelihood of cows developing endometritis and to their subsequent fertility.

The role of endosomal signaling triggered by metastatic growth factors in tumor progression

Within tumor microenvironment, a lot of growth factors such as hepatocyte growth factor and epidermal growth factor may induce similar signal cascade downstream of receptor tyrosine kinase (RTK) and trigger tumor metastasis synergistically. In the past decades, the intimate relationship of RTK-mediated receptor endocytosis with signal transduction was well established. In general, most RTK undergoes clathrin-dependent endocytosis and/or clathrin-independent endocytosis. The internalized receptors may sustain the signaling within early endosome, recycling to plasma membrane for subsequent ligand engagement or sorting to late endosomes/lysosome for receptor degradation. Moreover, receptor endocytosis influences signal transduction in a temporal and spatial manner for periodical and polarized cellular processes such as cell migration. The endosomal signalings triggered by various metastatic factors are quite similar in some critical points, which are essential for triggering cell migration and tumor progression. There are common regulators for receptor endocytosis including dynamin, Rab4, Rab5, Rab11 and Cbl. Moreover, many critical regulators within the RTK signal pathway such as Grb2, p38, PKC and Src were also modulators of endocytosis. In the future, these may constitute a new category of targets for prevention of tumor metastasis.