Tissue microarray analysis reveals strong clinical evidence for a close association between loss of annexin A1 expression and nodal metastasis in gastric cancer

Association of High Immunohistochemical Expression of Minichromosome Maintenance 3 with Human Oral Squamous Cell Carcinoma-A Preliminary Study

BACKGROUND

Oral squamous cell carcinoma (OSCC) may arise from premalignant oral lesions (PMOL) in most cases. Minichromosome maintenance 3 (MCM3) is a proliferative marker that has been investigated as a potential diagnostic biomarker in the diagnosis of oral cancer.

OBJECTIVES

To evaluate the association of MCM3 expression, its clinicopathologic parameters and to identify snuff (also called naswar) as a potential risk factor for changes in MCM3 expression in PMOL and OSCC.

METHODOLOGY

Immunohistochemistry (IHC) of MCM3 was performed on 32 PMOL, 32 OSCC and 16 normal controls after optimization of IHC methodology. Histoscore (0-300) was used as a scoring system and seven different cut-offs were identified for analyses. Data were analyzed using various statistical tests.

RESULTS

Among the seven cutoffs, 40% strong positive cells were found to be a better cut-off as they were associated with many pathological variables (Broder's grade, Aneroth's grade, and mitotic activity). The differential MCM3 expression in oral lesions (PMOL and OSCC) was statistically significant (p = 0.03). Moreover, MCM3 expression is raised with increased duration and frequency of snuff use.

CONCLUSION

High MCM3 expression is associated with disease progression and is a potential indicator of malignant transformations from PMOL to OSCC. Moreover, the use of snuff is associated with MCM3 over-expression.

Identification of hub genes specific to pulmonary metastasis in osteosarcoma through integrated bioinformatics analysis

BACKGROUND

Pulmonary metastasis is the most frequent cause of death in osteosarcoma (OS) patients. Recently, several bioinformatics studies specific to pulmonary metastatic osteosarcoma (PMOS) have been applied to identify genetic alterations. However, the interpretation and reliability of the results obtained were limited for the independent database analysis.

OBJECTIVE

The expression profiles and key pathways specific to PMOS remain to be comprehensively explored. Therefore, in our study, three original datasets of GEO database were selected.

METHODS

Initially, three microarray datasets (GSE14359, GSE14827, and GSE85537) were downloaded from the GEO database. Differentially expressed genes (DEGs) between PMOS and nonmetastatic osteosarcoma (NMOS) were identified and mined using DAVID. Subsequently, GO and KEGG pathway analyses were carried out for DEGs. Corresponding PPI network of DEGs was constructed based on the data collected from STRING datasets. The network was visualized with Cytoscape software, and ten hub genes were selected from the network. Finally, survival analysis of these hub genes also used the TARGET database.

RESULTS

In total, 569 upregulated and 1238 downregulated genes were filtered as DEGs between PMOS and NMOS. Based on the GO analysis result, these DEGs were significantly enriched in the anatomical structure development, extracellular matrix, biological adhesion, and cell adhesion terms. Based on the KEGG pathway analysis result, these DEGs were mainly enriched in the pathways in cancer, PI3K-Akt signaling, MAPK signaling, focal adhesion, cytokine-cytokine receptor interaction, and IL-17 signaling. Hub genes (ANXA1 and CXCL12) were significantly associated with overall survival time in OS patient.

CONCLUSION

Our results may provide new insight into pulmonary metastasis of OS. However, experimental studies remain necessary to elucidate the biological function and mechanism underlying PMOS.

Predicting gastric cancer outcome from resected lymph node histopathology images using deep learning

N-staging is a determining factor for prognostic assessment and decision-making for stage-based cancer therapeutic strategies. Visual inspection of whole-slides of intact lymph nodes is currently the main method used by pathologists to calculate the number of metastatic lymph nodes (MLNs). Moreover, even at the same N stage, the outcome of patients varies dramatically. Here, we propose a deep-learning framework for analyzing lymph node whole-slide images (WSIs) to identify lymph nodes and tumor regions, and then to uncover tumor-area-to-MLN-area ratio (T/MLN). After training, our model’s tumor detection performance was comparable to that of experienced pathologists and achieved similar performance on two independent gastric cancer validation cohorts. Further, we demonstrate that T/MLN is an interpretable independent prognostic factor. These findings indicate that deep-learning models could assist not only pathologists in detecting lymph nodes with metastases but also oncologists in exploring new prognostic factors, especially those that are difficult to calculate manually.

The ratio of tumour area to metastatic lymph node area (T/MLN) is a clinical indicator that can improve prognosis prediction of gastric cancer. Here, the authors use machine learning on whole slide images to generate a method that can predict metastatic lymph nodes and obtain T/MLN.

Effect of Curcumin and Its Derivates on Gastric Cancer: Molecular Mechanisms

Gastric carcinoma is one of the most prevalent malignancies and is associated with a high mortality. Chemotherapy is the principal therapeutic option in the treatment of gastric cancer, but its success rate is restricted by severe side effects and the prevalence of chemo-resistance. Curcumin is a polyphenolic compound derived from turmeric that has potent antioxidant, anti-inflammatory and anti-tumor effects. There is accumulating evidence that curcumin may prevent gastric cancer through regulation of oncogenic pathways. Furthermore some curcumin analogues and novel formulation of curcumin appear to have anti-tumor activity. The aim of this review was to give an overview of the therapeutic potential of curcumin and its derivatives against gastric cancer in preclinical and clinical studies.

Advancements of Annexin A1 in inflammation and tumorigenesis

Annexin A1 is a Ca²⁺-dependent phospholipid binding protein involved in a variety of pathophysiological processes. Accumulated evidence has indicated that Annexin A1 has important functions in cell proliferation, apoptosis, differentiation, metastasis, and inflammatory response. Moreover, the abnormal expression of Annexin A1 is closely related to the occurrence and development of tumors. In this review article, we focus on the structure and function of Annexin A1 protein, especially the recent evidence of Annexin A1 in the pathophysiological role of inflammatory and cancer. This summary will be very important for further investigation of the pathophysiological role of Annexin A1 and for the development of novel therapeutics of inflammatory and cancer based on targeting Annexin A1 protein.

Annexin A1-suppressed autophagy promotes nasopharyngeal carcinoma cell invasion and metastasis by PI3K/AKT signaling activation

Annexin A1 (ANXA1) is dysregulated in the various tumors. However, the role and mechanism of ANXA1 in the cancers are poorly understood. In this study, we first showed a clinically positive correlation between ANXA1 and autophagy-associated protein SQSTM1 expression in nasopharyngeal carcinoma (NPC) and ANXA1-regulating SQSTM1 expression through autophagy, and further demonstrated that ANXA1 inhibited BECN1 and ATG5-dependent autophagy in the NPC cells. Using phospho-kinase antibody array to identify signaling through which ANXA1 regulated NPC cell autophagy, we found that ANXA1-suppressed autophagy was associated with PI3K/AKT signaling activation. We also showed that ANXA1 expression was significantly increased in the NPCs with metastasis relative to NPCs without metastasis and positively correlated with lymphonode and distant metastasis; high ANXA1 expression in the NPC cells promoted in vitro tumor cell migration and invasion and in vivo metastasis. Lastly, we showed that inhibition of autophagy restored the ability of tumor cell migration and invasion, epithelial–mesenchymal transition (EMT)-like alterations and in vivo metastasis in the ANXA1 knockdown NPC cells with autophagy activation; ANXA1-suppresed autophagy induced EMT-like alterations possibly by inhibiting autophagy-mediated degradation of Snail. Our data suggest that ANXA1-suppressed autophagy promotes NPC cell migration, invasion and metastasis by activating PI3K/AKT signaling pathway, highlighting that the activation of autophagy may inhibit metastasis of NPC with high ANXA1 expression.

Molecular background of the regional lymph node metastasis of gastric cancer

Gastric cancer (GC) is one of the deadliest types of cancer in the world. Lymph node (LN) metastasis is a complex and malignant behavior of GC, involving a sequence of biological processes, including decreased adherence to adjacent cells, extracellular matrix (ECM) degradation and lymphatic channel permeation. LN metastasis is directly associated with the treatment response, local recurrence and long-term survival of patients with GC. Therefore, the molecular mechanisms of LN metastasis in GC development require further investigation. Recently, a large number of clinical studies have focused on the molecular mechanisms and biological markers of tumor invasion and metastasis. However, few articles have broadly summarized LN metastasis in GC, and the molecular mechanisms of LN metastasis are not yet fully understood. In the present review, the molecular mechanisms of LN metastasis in GC will be discussed, including the following aspects: Cell adhesion and movement, ECM degradation, new vessel formation, and molecular pattern differences between metastatic LNs and the primary tumor. This review may lead to a better understanding of LN metastasis in GC, and the identification of new diagnostic markers.

Expression profiles of Annexin A1, formylated peptide receptors and cyclooxigenase-2 in gastroesophageal inflammations and neoplasias

The anti-inflammatory protein Annexin-A1 (ANXA1) is associated to tumor invasion process and its actions can be mediated by formylated peptides receptors (FPRs). Therefore, we evaluated the expression and correlation of ANXA1, FPR and cyclooxygenase-2 (COX-2) enzyme in esophageal and stomach inflammations and neoplasias. The study of proteins was performed by immunohistochemistry in biopsies of esophagitis, Barrett's esophagus, squamous cell carcinoma and adenocarcinoma of the esophagus, as well as gastritis, stomach polypus and gastric adenocarcinoma. The intensity of the expressions was evaluated by densitometry. The immunohistochemical and densitometric analyzes showed specificity for the FPR1 receptor and modulation of the ANXA1, COX-2 and FPR1 expressions in the epithelial cells in the different studied conditions. Increased immunoreactivity of these proteins was observed in cases of inflammation and stomach polypus. Interestingly, moderate immunoreactivity for ANXA1 and FPR1 but increased immunolabeling for COX-2 were observed in Barrett́s esophagus and esophageal adenocarcinomas. Also, there was reduced expression of ANXA1 and FPR1 in esophageal carcinoma but COX-2 overexpression in this tumor. There was no expression of FPR2 but ANXA1 and FPR1 expressions were positively correlated in all clinical conditions studied. Positive correlation between ANXA1 and COX-2 were also observed in inflammation conditions while negative correlation between ANXA1 and COX-2 was observed in esophageal carcinoma. Our results demonstrate the unregulated expression of ANXA1 and COX-2 in precursor lesions of esophageal and stomach cancers, reinforcing their involvement in gastroesophageal carcinogenesis. In addition, the data show that the actions of ANXA1 in the inflammatory and neoplastic processes of the esophagus and stomach are specifically mediated by the FPR1 receptor.

Evaluation of miRNA-196a2 and apoptosis-related target genes: ANXA1, DFFA and PDCD4 expression in gastrointestinal cancer patients: A pilot study

Previous reports have suggested the significant association of miRNAs aberrant expression with tumor initiation, progression and metastasis in cancer, including gastrointestinal (GI) cancers. The current preliminary study aimed to evaluate the relative expression levels of miR-196a2 and three of its selected apoptosis-related targets; ANXA1, DFFA and PDCD4 in a sample of GI cancer patients. Quantitative real-time PCR for miR-196a2 and its selected mRNA targets, as well as immunohistochemical assay for annexin A1 protein expression were detected in 58 tissues with different GI cancer samples. In addition, correlation with the clinicopathological features and in silico network analysis of the selected molecular markers were analyzed. Stratified analyses by cancer site revealed elevated levels of miR-196a2 and low expression of the selected target genes. Annexin protein expression was positively correlated with its gene expression profile. In colorectal cancer, miR-196a over-expression was negatively correlated with annexin A1 protein expression (r = -0.738, p < 0.001), and both were indicators of unfavorable prognosis in terms of poor differentiation, larger tumor size, and advanced clinical stage. Taken together, aberrant expression of miR-196a2 and the selected apoptosis-related biomarkers might be involved in GI cancer development and progression and could have potential diagnostic and prognostic roles in these types of cancer; particularly colorectal cancer, provided the results experimentally validated and confirmed in larger multi-center studies.

Increased SNAT1 is a marker of human osteosarcoma and potential therapeutic target

Background

SLC38A1/SNAT1 has been found to play an essential role in human development, but its role in osteosarcoma (OS) has yet to be evaluated. The purpose of this study was to assess the expression of SLC38A1/SNAT1 in patients with OS, and further investigate the mechanisms by which it affects tumor growth and metastasis.

Methods

Tissue microarray blocks and immunohistochemical studies were carried out to assess the expression of SNAT1 in 165 OS specimens. Its correlation with clinicopathological characteristics was then analyzed. The function of SNAT1 in OS cells was investigated by silencing SNAT1 using SNAT1-shRNA in vitro and in vivo.

Results

SNAT1 was highly expressed in 85% OS and significantly closely associated with pulmonary metastasis. Patients with high SNAT1 expression survived for shorter periods than those with low SNAT1 expression. Suppression of endogenous SNAT1 led to inhibition of cell proliferation, cell colony formation, and cell migration in vitro, and retarded tumor growth in xenograft models. Silencing SNAT1 reduced expression of MMP9, vimentin, fibronectin, p-Akt, p-mTOR, and VEGF.

Conclusions

Our results indicated that increased expression of SNAT1 is a common event in OS. SNAT1 played an essential role in the development and progression of osteosarcoma, which may serve as a prognostic and therapeutic marker of OS.

FPR2 promotes invasion and metastasis of gastric cancer cells and predicts the prognosis of patients

Formyl peptide receptor 2 (FPR2), a classical chemoattractant receptor of G-protein-coupled receptors, is reported to be involved in invasion and metastasis of some cancers, but the role of FPR2 in gastric cancer (GC) has not yet been elucidated. In this study, we found that the levels of FPR2 expression in GC were positively correlated with invasion depth, lymph node metastasis and negatively correlated with the patients’ overall survival. Multivariate analysis indicated that FPR2 expression was an independent prognostic marker for GC patients. FPR2-knockdown significantly abrogated the migration and invasion stimulated by Hp(2–20) and Ac(2–26), two well-characterized ligands for FPR2 in GC cells. FPR2 deletion also reduced the tumorigenic and metastatic capabilities of GC cells in vivo. Mechanistically, stimulation with FPR2 ligands resulted in down-regulation of E-cadherin and up-regulation of vimentin, which were reversed by FPR2 knock-down, implying the involvement of epithelial–mesenchymal transition (EMT). Moreover, the activation of FPR2 was accompanied with ERK1/2 phosphorylation, which could be attenuated by FPR2 silencing or treatment with MEK inhibitor, PD98059. Altogether, our results demonstrate that FPR2 is functionally involved in invasion and metastasis, and potentially acts as a novel prognostic marker as well as a potential therapeutic target in human GC.

SLC38A1 promotes proliferation and migration of human colorectal cancer cells

Current studies have demonstrated that SLC38A1 proteins play a causal role in neoplastic cell transformation. The twofold aim of this study was to provide insight into whether a variance in the expression of SLC38A1 exists between human colorectal cancer and healthy human tissues and to determine how silencing or overexpressing the SLC38A1 gene could affect the proliferation, viability and migration of colorectal cancer cells. Immunohistochemical staining was used to analyze the expression of SLC38A1 in colorectal cancer tissues and adjacent normal mucosa in 77 patients who underwent surgical resection. The expression of SLC38A1 in colorectal cancer tissues and cell lines was detected using RT-PCR and Western blotting. Two colorectal cancer cell lines SW480 and HCT116 were used to examine whether silencing SLC38A1 with siRNA and overexpressing SLC38A1 with shRNA could affect cell viability and migration. As a result, the SLC38A1 protein was very low or undetectable in the normal colon mucosa. In contrast, strong staining of SLC38A1 protein was found in the cytoplasm in 79.2% colorectal cancer samples. More pronounced SLC38A1 expression in colorectal cancer tissues was significantly associated with tumor node metastasis (TNM) stage. Inhibition of SLC38A1 reduced tumour growth and suppressed proliferation and migration of SW480 cells. In contrast, overexpression of SLC38A1 had the opposite effects on HCT116 cells. SLC38A1 is overexpressed in colorectal cancer, which suggests that it is associated with tumour progression. These results encourage the exploration of SLC38A1 as a target for intervention in colorectal cancer.

Key Genes in Stomach Adenocarcinoma Identified via Network Analysis of RNA-Seq Data

RNA-seq data of stomach adenocarcinoma (STAD) were analyzed to identify critical genes in STAD. Meanwhile, relevant small molecule drugs, transcription factors (TFs) and microRNAs (miRNAs) were also investigated. Gene expression data of STAD were downloaded from The Cancer Genome Atlas (TCGA). Differential analysis was performed with package edgeR. Relationships with correlation coefficient > 0.6 were retained in the gene co-expression network. Functional enrichment analysis was performed for the genes in the network with DAVID and KOBASS 2.0. Modules were identified using Cytoscape. Relevant small molecules drugs, transcription factors (TFs) and microRNAs (miRNAs) were revealed by using CMAP and WebGestalt databases. A total of 520 DEGs were identified between 285 STAD samples and 33 normal controls, including 244 up-regulated and 276 down-regulated genes. A gene co-expression network containing 53 DEGs and 338 edges was constructed, the genes of which were significantly enriched in focal adhesion, ECM-receptor interaction and vascular smooth muscle contraction pathways. Three modules were identified from the gene co-expression network and they were associated with skeletal system development, inflammatory response and positive regulation of cellular process, respectively. A total of 20 drugs, 9 TFs and 6 miRNAs were acquired that may regulate the DEGs. NFAT-COL1A1/ANXA1, HSF2-FOS, SREBP-IL1RN and miR-26-COL5A2 regulation axes may be important mechanisms for STAD.

Identification of specific biomarkers for gastric adenocarcinoma by ITRAQ proteomic approach

The aim of this study was to identify biomarkers for gastric cancer (GC) by iTRAQ. Using proteins extracted from a panel of 4 pairs of gastric adenocarcinoma samples (stage III-IV, Her-2 negative), we identified 10 up regulated and 9 down regulated proteins in all four pairs of GC samples compared to adjacent normal gastric tissue. The up regulated proteins are mainly involved in cell motility, while the down regulated proteins are mitochondrial enzymes involved in energy metabolism. The expression of three up regulated proteins (ANXA1, NNMT, fibulin-5) and one of the down regulated proteins (UQCRC1) was validated by Western Blot in 97 GC samples. ANXA1 was up regulated in 61.36% of stage I/II GC samples compared to matched adjacent normal gastric tissue, and its expression increased further in stage III/IV samples. Knockdown of ANXA1 by siRNA significantly inhibited GC cell migration and invasion, whereas over expression of ANXA1 promoted migration and invasion. We found decreased expression of UQCRC1 in all stages of GC samples. Our data suggest that increased cell motility and decreased mitochondrial energy metabolism are important hallmarks during the development of GC.

Annexin A2 and alpha actinin 4 expression correlates with metastatic potential of primary endometrial cancer

The prediction of lymph node metastasis using clinic-pathological data and molecular information from endometrial cancers lacks accuracy and is therefore currently not routinely used in patient management. Consequently, although only a small percentage of patients with endometrial cancers suffer from metastasis, the majority undergo radical surgery including removal of pelvic lymph nodes. Upon analysis of publically available data and published research, we compiled a list of 60 proteins having the potential to display differential abundance between primary endometrial cancers with versus those without lymph node metastasis. Using data dependent acquisition LC-ESI-MS/MS we were able to detect 23 of these proteins in endometrial cancers, and using data independent LC-ESI-MS/MS the differential abundance of five of those proteins was observed. The localization of the differentially expressed proteins, was visualized using peptide MALDI MSI in whole tissue sections as well as tissue microarrays of 43 patients. The proteins identified were further validated by immunohistochemistry. Our data indicate that annexin A2 protein level is upregulated, whereas annexin A1 and α actinin 4 expression are downregulated in tumours with lymph node metastasis compared to those without lymphatic spread. Moreover, our analysis confirmed the potential of these markers, to be included in a statistical model for prediction of lymph node metastasis. The predictive model using highly ranked m/z values identified by MALDI MSI showed significantly higher predictive accuracy than the model using immunohistochemistry data. In summary, using publicly available data and complementary proteomics approaches, we were able to improve the prediction model for lymph node metastasis in EC.

Changes in the in vitro activity of platinum drugs when administered in two aliquots

BACKGROUND

The management of ovarian cancer remains a challenge. Because of the lack of early symptoms, it is often diagnosed at a late stage when it is likely to have metastasized beyond ovaries. Currently, platinum based chemotherapy is the primary treatment for the disease. However acquired drug resistance remains an on-going problem. As cisplatin brings about apoptosis by intrinsic and extrinsic pathways, this study aimed to determine changes in activity of platinum drugs when administered in two aliquots as against a bolus and sought to determine association with changes in GSH, speciation of platinum drugs and changes in protein expression.

METHODS

The efficacy of administering cisplatin, carboplatin and oxaliplatin in two aliquots with a time gap was investigated in ovarian A2780, A2780(cisR), A2780(ZD0473R) and SKOV-3 cell lines. The cellular accumulation of platinum, level of platinum - DNA binding and cellular glutathione level were determined, and proteomic studies were carried out to identify key proteins associated with platinum resistance in ovarian A2780(cisR) cancer cell line.

RESULTS

Much greater cell kill was observed with solutions left standing at room temperature than with freshly prepared solutions, indicating that the increase in activity on ageing was related to speciation of the drug in solution. Proteomic studies identified 72 proteins that were differentially expressed in A2780 and A2780(cisR) cell lines; 22 of them were restored back to normal levels as a result of synergistic treatments, indicating their relevance in enhanced drug action.

CONCLUSIONS

The proteins identified are relevant to several different cellular functions including invasion and metastasis, cell cycle regulation and proliferation, metabolic and biosynthesis processes, stress-related proteins and molecular chaperones, mRNA processing, cellular organization/cytoskeleton, cellular communication and signal transduction. This highlights the multifactorial nature of platinum resistance in which many different proteins with diverse functions play key roles. This means multiple strategies can be harnessed to overcome platinum resistance in ovarian cancer. The results of the studies can be significant both from fundamental and clinical view points.

Metformin potentiates rapamycin and cisplatin in gastric cancer in mice

Here we showed that pAMPKα and PTEN were down-regulated and p-mTOR, p-S6, p-4EBP1, MMP7, and DCN1 were up-regulated in human gastric cancer tissue samples as compared to that in the noncancerous tissues. Metformin inhibited tumor growth in mice. Also it enhanced cisplatin- or rapamycin-induced reduction of tumor growth as compared with treatment of either drug alone. In addition to activation of AMPK and suppression of the mTOR pathway, a series of increased and decreased genes expression were induced by metformin, including PTEN, MMP7, and FN1. We suggest that metformin could potentially be used for the treatment of gastric cancer especially in combination with cisplatin or rapamycin.

Annexin A1 sustains tumor metabolism and cellular proliferation upon stable loss of HIF1A

Despite the approval of numerous molecular targeted drugs, long-term antiproliferative efficacy is rarely achieved and therapy resistance remains a central obstacle of cancer care. Combined inhibition of multiple cancer-driving pathways promises to improve antiproliferative efficacy. HIF-1 is a driver of gastric cancer and considered to be an attractive target for therapy. We noted that gastric cancer cells are able to functionally compensate the stable loss of HIF-1α. Via transcriptomics we identified a group of upregulated genes in HIF-1α-deficient cells and hypothesized that these genes confer survival upon HIF-1α loss. Strikingly, simultaneous knock-down of HIF-1α and Annexin A1 (ANXA1), one of the identified genes, resulted in complete cessation of proliferation. Using stable isotope-resolved metabolomics, oxidative and reductive glutamine metabolism was found to be significantly impaired in HIF-1α/ANXA1-deficient cells, potentially explaining the proliferation defect. In summary, we present a conceptually novel application of stable gene inactivation enabling in-depth deconstruction of resistance mechanisms. In theory, this experimental approach is applicable to any cancer-driving gene or pathway and promises to identify various new targets for combination therapies.

Identification of ANXA1 as a lymphatic metastasis and poor prognostic factor in pancreatic ductal adenocarcinoma

OBJECTIVE

The aim of this study was to investigate the clinical significance of annexin a1 (ANXA1) and provide molecular evidence to support that decreased ANXA1 expression could enhance cancer migration and invasion in pancreatic ductal adenocarcinoma (PDAC).

MATERIALS AND METHODS

Immunohistochemistry of a tissue microarray with 162 surgically resected PDAC specimens was performed to examine the expression of ANXA1. We also investigated the relationship between ANXA1 expression and clinicopathological factors and prognosis of PDAC patients. We further studied the role of ANXA1 in PDAC cell proliferation, migration and invasion by cell proliferation assay, migration assay and matrigel invasion assay with reduced ANXA1 expression by RNAi. Western blotting was used to detect matrix metalloproteinase-9 (MMP-9), and tissue inhibitor of metalloproteinase-1 (TIMP-1) expression. We also detected MMP-9 enzyme activity by gelatin zymography.

RESULTS

Decreased expression of ANXA1 was significantly associated with poor differentiation, lymph node metastasis and advanced TNM stage of PDAC patients (p<0.05). Moreover, decreased expression of ANXA1 was correlated with poor survival (p<0.05). Furthermore, we found that ANXA1 knockdown inhibited cell proliferation, induced G1 phase cell cycle arrest, increased PDAC cell migration and invasion capacity compared with controls. In addition, Western blotting showed that ANXA1 knockdown increased the MMP-9 protein level and decreased TIMP-1 expression. Gelatin zymography showed that MMP-9 enzyme activity was also elevated.

CONCLUSIONS

Negative ANXA1 expression is a most unfavorable prognostic factor for PDAC patients. ANXA1 knockdown inhibits cell proliferation by inducing G1 phase cell cycle arrest and increases migration and invasion of PDAC cells through up-regulating MMP-9 expression and activity, implying that ANXA1 may serve as a promising prognostic biomarker and therapeutic target for PDAC.

Reciprocal expression of p-AMPKa and p-S6 is strongly associated with the prognosis of gastric cancer

Activation of AMP-activated protein kinase (AMPK) suppressed mammalian target of rapamycin (mTOR) pathway, resulting in impaired cancer cell proliferation. Two cohorts (50 and 1072 cases) of patients with resected gastric adenocarcinoma were enrolled in the study. Immunohistochemical staining for p-AMPKa, p-ACC, p-mTOR, p-S6, and p-4EBP1 was performed on the 50-patient cohort. Tissue microarray blocks containing samples from 1072 patients of Chinese ethnicity were used for the immunohistochemical detection of p-AMPKa and p-S6 levels. p-AMPK and p-ACC were frequently inactivated in both cohorts of gastric cancer samples, while p-mTOR, p-S6, and p-4EBP1 were frequently activated in the small cohort of gastric cancer. However, only levels of p-AMPKa and p-S6 were associated with the overall survival of gastric cancer patients. In the larger 1072-patient cohort, downregulation of p-AMPKa and upregulation of p-S6 were associated with tumor progression and were independent predictors of survival after resection of primary gastric cancer. Therefore, reciprocal expression of p-AMPKa and p-S6 may be promising prognostic biomarkers in patients with gastric cancer.

SPARCL1 is a novel predictor of tumor recurrence and survival in hilar cholangiocarcinoma

Secreted protein acidic and rich in cysteines-like protein 1 (SPARCL1) has been implicated in tumor initiation, formation, and progression of various cancers, yet its role in hilar cholangiocarcinoma remains largely uncharacterized. In the present study, tissue microarrays containing resected hilar cholangiocarcinoma specimens from 92 patients were used to evaluate the expression of SPARCL1 protein by immunohistochemistry (IHC). In vitro assays were used to determine the effect of SPARCL1 overexpression on cell growth and migration. Loss of SPARCL1 expression was observed in 46 (50.0 %) of the 92 primary tumors. SPARCL1 expression is inversely associated with poorly or undifferentiation specimens (P = 0.030) in addition to lymph node metastasis (P = 0.047). Survival analysis demonstrated that SPARCL1 is an independent factor in predicting the outcome of patients with hilar cholangiocarcinoma. SPARCL1 overexpression suppressed tumor cell migration in vitro by inhibiting MMP-9, MMP-2, Vimentin, and Fibronectin expression, whereas did not inhibit cell proliferation in vitro. Our results suggest that loss of SPARCL1 is involved in the tumorigenesis of hilar cholangiocarcinoma and may serve as a novel molecular biomarker for patients' outcome.

Regulatory mechanisms of annexin-induced chemotherapy resistance in cisplatin resistant lung adenocarcinoma

Adenocarcinoma of lung has high incidence and a poor prognosis, woith chemotherapy as the main therapeutic tool, most commonly with cisplatin. However, chemotherapy resistance develops in the majority of patients during clinic treatment. Mechanisms of resistance are complex and still unclear. Although annexin play important roles in various tumor resistance mechanisms, their actions in cisplatin-resistant lung adenocarcinoma remain unclear. Preliminary studies by our group found that in cisplatin-resistant lung cancer A549 cells and lung adenocarcinoma tissues, both mRNA and protein expression of annexins A1, A2 and A3 is increased. Using a library of annexin A1, A2 and A3 targeting combined molecules already established by ourselves we found that specific targeting decreased cisplatin-resistance. Taken together, the underlined effects of annexins A1, A2 and A3 on drug resistance and suggest molecular mechanisms in cisplatin-resistant A549 cells both in vivo and in vitro. Furthermore, the study points to improved research on occurrence and development of lung adenocarcinoma, with provision of effective targets and programmes for lung adenocarcinoma therapy in the clinic.

Differential expression of ANXA1 in benign human gastrointestinal tissues and cancers

Background

Annexin-1 contributes to the pathological consequence and sequelae of most serious human diseases including cardiovascular disease and cancer. Although diverse roles in carcinogenesis have been postulated, its role in human gastrointestinal cancers still remains controversial.

Methods

The mRNA and protein expression profiles of ANXA1 were studied in human esophageal, gastric, pancreatic, colorectal, liver, and bile duct cancers using Real-Time PCR, western blotting, and immunohistochemistry. Gain/loss-of-function by pcDNA3.1-ANXA1 and ANXA1-shRNA was performed in gastric cancer cells.

Results

ANXA1 was widely expressed in adult gastrointestinal tissue. All methods showed that ANXA1 was down-regulated in esophageal, gastric, and bile duct cancers, but up-regulated in pancreatic cancer. Forced ANXA1 expression in gastric cancer cells leads to cell growth inhibition and concomitantly modulates COX-2 expression. We confirm loss of ANXA1 and overexpression of COX-2 in clinical gastric cancer, suggesting that the anti-proliferative function of ANXA1 against COX-2 production might be lost.

Conclusions

ANXA1 expression is “tumor-specific” and might play a multifaceted role in cancer development and progression. ANXA1 was widely expressed in normal gastrointestinal epithelium, suggesting its role in the maintenance of cellular boundaries. Furthermore, ANXA1 regulates GC cell viability via the COX-2 pathway.

Annexin A1 in primary tumors promotes melanoma dissemination

Metastatic melanoma is one of the most aggressive forms of skin cancer and has a poor prognosis. We have previously identified Annexin A1 (ANXA1) as a potential murine melanoma-spreading factor that may modulate cell invasion by binding to formyl peptide receptors (FPRs). Here, we report that (1) in a B16Bl6 spontaneous metastasis model, a siRNA-induced decrease in tumoral ANXA1 expression significantly reduced tumoral MMP2 activity and number of lung metastases; (2) in a retrospective study of 61 patients, metastasis-free survival was inversely related to ANXA1 expression levels in primary tumors (HR 3.15 [1.03-9.69], p = 0.045); (3) in human melanoma cell lines, ANXA1 level was positively correlated with in vitro invasion capacity whereas normal melanocytes contained low ANXA1 levels, and (4) the ANXA1 N-terminal peptide ANXA12-26 stimulated MMP2 activity after interaction with FPRs and significantly stimulated the in vitro invasion of melanomas by acting on FPRs. These findings identify ANXA1 as a proinvasive protein in melanoma that holds promise as a potential prognostic marker and therapeutic target.

Increased expression of phospho-acetyl-CoA carboxylase protein is an independent prognostic factor for human gastric cancer without lymph node metastasis

Upregulation of acetyl-CoA carboxylase (ACC), as a rate-limiting enzyme of fatty acid synthesis,has been recognized in multiple human cancers, implicating a critical role in cancer development and progression; yet, its role in gastric cancer still remains unclear. In the present study, we detected ACC and phosphorylated form of ACC (pACC) expression in gastric cancers and explored its clinical significance. Tissue microarray blocks containing primary gastric cancer and adjacent normal mucosa specimens obtained from 1,072 Chinese patients were used for the detection of ACC and pACC expression by immunohistochemistry. Gastric cancer cell lines were treated by metformin, and pACC was measured by Western blotting. ACC overexpression was observed in all the tumor specimens. High expression of pACC was found in 630 (58.8 %) of the 1,072 primary tumors and in 237 (66.6 %) of the 356 primary tumors without lymph node metastasis. Absent/low expression of pACC significantly correlated with advanced T stage (P < 0.001), tumor size (P = 0.010), lymph node metastasis (P < 0.001), advanced disease stage (P < 0.001), and poor histological differentiation (P = 0.014) in 1,072 primary tumors, and with advanced T stage (P = 0.015), tumor size (P = 0.017), and poor histological differentiation (P = 0.001) in 356 tumors without lymph node metastasis. Kaplan-Meier analysis showed that high expression of pACC is strongly related to better survival rates in all gastric cancer patients (P = 0.006). Cox regression analysis revealed that pACC is an independent prognostic factor only in patients without lymph node metastasis (P = 0.016). Metformin treatment leaded to increased expression of pACC, which, in turn, resulted in the reduction of cell proliferation and colony formation of gastric cancer cells (P < 0.05). Increased activation of ACC is frequent in human gastric cancer, and downregulation of pACC is an important prognostic factor, suggesting that ACC/pACC might be a potential target for cancer intervention.

Relationship between HPV and the biomarkers annexin A1 and p53 in oropharyngeal cancer

Background

Human papillomavirus (HPV) is often present in oropharyngeal cancers. Head and neck tumors have been examined for other molecular markers including p53 and annexin A1 (ANXA1). Here, we investigated the prevalence of HPV and its relationship with p53 and ANXA1 in patients with oropharyngeal cancer.

Methods

We have analyzed tumor and adjacent mucosa from 22 patients with squamous cell carcinoma of the oropharynx in addition to samples of the oropharyngeal epithelium in subjects without cancer. We evaluated the presence of the HPV (subtypes 16/18 and 31/33) by chromogenic in situ hybridization. Additionally, we used immunofluorescence to examine the expression of p16, p53, ANXA1 and the phosphorylation of the ANXA1 residues Ser27 (ANXA1-SER) and Tyr21 (ANXA1-TYR).

Results

We have detected the presence of HPV genome in 59% of the 22 tumors. Of those, 92% were also positive for p16 immunostaining. Furthermore, we demonstrated a reduction in the expression of p53 in HPV + compared to HPV- tumors. Also, a reduction was observed in the expression of ANXA1 in tumors compared to epithelium from the margins and from controls. We also noted a reduction in ANXA1-TYR in tumors. However, the expression of both ANXA1 and ANXA1-SER were elevated in the margins of the HPV + versus HPV- tumors.

Conclusions

Our results confirm a high prevalence of HPV in oropharyngeal cancer and a reduction in p53 expression in HPV + tumors. We observed a hypoexpression of ANXA1 and ANXA1-TYR in oropharyngeal cancer. The increase in ANXA1-SER in the margins of HPV + tumors suggests that the epithelium in these cases had been activated by an infectious agent. Those findings indicate that ANXA1 and its phosphorylated forms can play important roles in the response to HPV infection and the carcinogenesis of the oropharynx.

Overexpression of SLC38A1 is associated with poorer prognosis in Chinese patients with gastric cancer

Background

Current literature has demonstrated that host glutamine depletion facilitates tumorigenesis. Likewise, the glutamine transporter SLC38A1 is putatively associated with malignant transformation and tumor progression. Taken together, this forms the premise for undertaking the current study. The twofold aim of this study was to provide insight into whether or not a variance in the expression of SLC38A1 exists between human gastric cancer and healthy human tissues, and to determine how silencing the SLC38A1 gene could affect the proliferation, viability, migration, and invasion of gastric cancer cells.

Methods

Immunohistochemical staining was used to analyze the expression of SLC38A1 in gastric cancer tissues and adjacent healthy mucosa in 896 patients with pathologically confirmed gastric cancer who had underwent R0 resection. SH-10-TC cells (a gastric cancer cell line) were used to examine whether silencing SLC38A1 with siRNA could affect cell viability, migration and invasion.

Results

The SLC38A1 protein was very low or undetectable in healthy gastric mucosa. In contrast, strong staining of SLC38A1 protein was found in the cytoplasm in 495 out of the 896 gastric cancer samples. More pronounced SLC38A1 expression in gastric cancer tissues was significantly associated with age, differentiation status, lymph node metastasis, TNM stage and PCNA (proliferating cell nuclear antigen) expression. Upon univariate survival analysis, SLC38A1 expression was correlated with poor survival. Multivariate survival analysis revealed that SLC38A1 was an independent prognostic factor.

Conclusion

SLC38A1 is overexpressed in gastric cancer, which suggests that it is contributory to tumor progression. These results encourage the exploration of SLC38A1 as a target for intervention in gastric cancer.

Annexin A1 in malignant tumors: current opinions and controversies

Annexin A1 is a 37 kDa calcium and phospholipid-binding protein that participates in several biological processes, such as inflammatory reactions, modulation of cell proliferation, regulation of cell death signaling, apoptosis, and, most importantly, tumor formation and development. Although annexin A1 has been implicated in the biology of various tumors, the findings are highly controversial and information regarding the underlying mechanism remains limited. Moreover, the mechanism by which annexin A1 participates in carcinogenesis and tumor progression is rather unclear. In the current study, we review the important biological functions of annexin A1 in different tumors. This work indicates that annexin A1 is a possible target for novel therapeutic intervention and that it is a potential biomarker for tumor diagnosis and screening.

Deregulation of annexin-A1 and galectin-1 expression in precancerous gastric lesions: intestinal metaplasia and gastric ulcer

OBJECTIVE

Annexin-A1 (ANXA1/AnxA1) and galectin-1 (LGALS1/Gal-1) are mediators that play an important role in the inflammatory response and are also associated with carcinogenesis. We investigated mRNA and protein expression in precancerous gastric lesions that participate in the progression cascade to gastric cancer, such as intestinal metaplasia (IM) and gastric ulcer (GU).

METHODS

Quantitative real-time PCR (qPCR) and immunohistochemical techniques were used to analyze the relative quantification levels (RQ) of ANXA1 and LGALS1 mRNA and protein expression, respectively.

RESULTS

Increased relative expression levels of ANXA1 were found in 100% of cases, both in IM (mean RQ = 6.22 ± 0.06) and in GU (mean RQ = 6.69 ± 0.10). However, the LGALS1 presented basal expression in both groups (IM: mean RQ = 0.35 ± 0.07; GU: mean RQ = 0.69 ± 0.09). Immunohistochemistry revealed significant positive staining for both the AnxA1 and Gal-1 proteins in the epithelial nucleus and cytoplasm as well as in the stroma of the IM and GU groups (P < 0.05) but absence or low immunorectivity in normal mucosa.

CONCLUSION

Our results bring an important contribution by evidencing that both the AnxA1 and Gal-1 anti-inflammatory proteins are deregulated in precancerous gastric lesions, suggesting their involvement in the early stages of gastric carcinogenesis, possibly due to an inflammatory process in the gastric mucosa.

Identification of Annexin A1 protein expression in human gastric adenocarcinoma using proteomics and tissue microarray

AIM: To study the differential expression of Annexin A1 (ANXA1) protein in human gastric adenocarcinoma. This study was also designed to analyze the relationship between ANXA1 expression and the clinicopathological parameters of gastric carcinoma.

METHODS: Purified gastric adenocarcinoma cells (GAC) and normal gastric epithelial cells (NGEC) were obtained from 15 patients with gastric cancer by laser capture microdissection. All of the peptide specimens were labeled as ¹⁸O/¹⁶O after trypsin digestion. Differential protein expressions were quantitatively identified between GAC and NGEC by nanoliter-reverse-phase liquid chromatography-mass/mass spectrometry (nano-RPLC-MS/MS). The expressions of ANXA1 in GAC and NGEC were verified by western blot analysis. The tissue microarray containing the expressed ANXA1 in 75 pairs of gastric carcinoma and paracarcinoma specimens was detected by immunohistochemistry (IHC). The relationship between ANXA1 expression and clinicopathological parametes of gastric carcinoma was analyzed.

RESULTS: A total of 78 differential proteins were identified. Western blotting revealed that ANXA1 expression was significantly upregulated in GAC (2.17/1, P < 0.01). IHC results showed the correlations between ANXA1 protein expression and the clinicopathological parameters, including invasive depth (T stage), lymph node metastasis (N stage), distant metastasis (M stage) and tumour-lymph node metastasis stage (P < 0.01). However, the correlations between ANXA1 protein expression and the remaining clinicopathological parameters, including sex, age, histological differentiation and the size of tumour were not found (P > 0.05).

CONCLUSION: The upregulated ANXA1 expression may be associated with carcinogenesis, progression, invasion and metastasis of GAC. This protein could be considered as a biomarker of clinical prognostic prediction and targeted therapy of GAC.

Mapping the interactome of overexpressed RAF kinase inhibitor protein in a gastric cancer cell line

BACKGROUND

Gastric cancer (GC) is a threat to human health with increasing incidence and mortality worldwide. Down-regulation or absence of RAF kinase inhibitor protein (RKIP) was associated with the occurrence, differentiation, invasion, and metastasis of GC. This study aims to investigate the molecular mechanisms and biological functions of RKIP in the GC biology.

METHODS

The fusion expression plasmid pcDNA3.1-RKIP-3xFLAG was transfected into SGC7901 cells, the RKIP fusion proteins were purified with anti-flag M2 magnetic beads, and the RKIP-interacting proteins were identified with tandem mass spectrometry (MS/MS), and were analyzed with bioinformatics tools. Western blot and co-immunoprecipitation were used to confirm the interaction complex.

RESULTS

A total of 72 RKIP-interacting proteins were identified by MS/MS. Those proteins play roles in enzyme metabolism, molecular chaperoning, biological oxidation, cytoskeleton organization, signal transduction, and enzymolysis. Three RKIP-interaction protein network diagrams were constructed with Michigan Molecular Interactions, functional linage network, and Predictome analysis to address the molecular pathways of the functional activity of RKIP. The MS/MS-characterized components of the existing interaction complex (RKIP, HSP90, 14-3-3ε, and keratin 8) were confirmed by Western blot analysis and co-immunoprecipitation.

CONCLUSION

This study is the first discovery of the interaction of RKIP with HSP90, 14-3-3, and keratin. The present data would provide insight into the molecular mechanisms of how RKIP inhibits the occurrence and development of GC.

Potential role of Anxa1 in cancer

The annexins are a well-known, closely related, multigene superfamily of Ca2+-regulated, phospholipid-dependent, membrane-binding proteins. As a member of the annexins, Anxa1 participates in a variety of important biological processes, such as cellular transduction, membrane aggregation, inflammation, phagocytosis, proliferation, differentiation and apoptosis. Accumulated evidence has indicated that Anxa1 deregulations are associated with the development, invasion, metastasis, occurrence and drug resistance of cancers. The research evidence in recent years indicates that Anxa1 might specifically function either as a tumor suppressor or a tumor promoter candidate for certain cancers depending on the particular type of tumor cells/tissues. This article summarizes the associations between Anxa1 and malignant tumors, as well as potential action mechanisms. Anxa1 has the potential to be used in the future as a biomarker for the diagnosis, treatment and prognosis of certain tumors.

Sodium butyrate induces growth inhibition and apoptosis in human prostate cancer DU145 cells by up-regulation of the expression of annexin A1

Background

Sodium butyrate, a histone deacetylase inhibitor, has emerged as a promising anticancer drug for multiple cancers. Recent studies have indicated that sodium butyrate could inhibit the progression of prostate cancer; however, the exact mechanism is still unclear. The aim of this study was to investigate the mechanism of sodium butyrate action in prostate cancer DU145 cells.

Methods

The inhibitory effects of NaB on cell growth were detected by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrrazolium bromide assay. Cell apoptosis was determined by flow cytometric analysis of DU145 cells stained with annexin V and PI. Hoechst 33258 and fluorescence microscopes were used to observe the nuclear morphology of DU145 cells after treatment with NaB. ANXA1 knockdown cells were established through transfection with ANXA1 siRNA. ANXA1 mRNA levels were measured by qRT-PCR. Bcl-2, Bax, ANXA1, ERK1/2 and pERK1/2 were detected by western blot.

Results

NaB significantly inhibited the growth and induction apoptosis of DU145 and PC3 cells in a dose-dependent manner. Expression of the anti-apoptosis gene Bcl-xl and Bcl-2 in DU145 cells are decreased and expression of the pro-apoptosis gene Bax and Bak increased after NaB treatment. Further studies have demonstrated that NaB up-regulated the expression of ANXA1 and that the tumor inhibition action of NaB was reduced markedly through knockdown of the ANXA1 gene in DU145 cells. Moreover, the siANXA1 cells showed that cell proliferation increased and cell apoptosis was induced by the inactivation of extracellular regulated kinase (ERK).

Conclusion

Our results support a significant correlation between NaB functions and ANXA1 expression in prostate cancer, and pave the way for further studying the molecular mechanism of NaB actions in cancers.

Activation of SNAT1/SLC38A1 in human breast cancer: correlation with p-Akt overexpression

BACKGROUND

SNAT1 is a subtype of the amino acid transport system A that has been implicated to play a potential role in cancer development and progression, yet its role in breast cancer remains unclear. In present study, we detected SNAT1 expression in breast cancers and explored its underlying mechanism in promoting breast carcinogenesis.

METHODS

RT-PCR and Western blotting were performed to analyze the transcription and protein levels of SNAT1 in breast cancer cell lines and fresh tissues. Tissue microarray blocks containing breast cancer specimens obtained from 210 patients were constructed. Expression of SNAT1 in these specimens was analyzed using immunohistochemical studies. SNAT1 was down-regulated by SNAT1-shRNA in breast cancer cells and the functional significance was measured.

RESULTS

SNAT1 was up-regulated in breast cancer cell lines and breast cancer tissues. Overexpression of SNAT1 was observed in 127 cases (60.5%). Expression of SNAT1 was significantly associated with tumor size, nodal metastasis, advanced disease stage, Ki-67, and ER status. Suppression of endogenous SNAT1 leads to cell growth inhibition, cell cycle arrest, and apoptosis of 4T1 cells and lowered the phosphorylation level of Akt. SNAT1 expression correlated significantly with p-Akt expression in human breast cancer samples.

CONCLUSIONS

The cross-talk between Akt signaling and SNAT1 might play a critical role in the development and progression of breast cancer, providing an important molecular basis for novel diagnostic markers and new attractive targets in the treatment of breast cancer patients.

Inhibitory effects of curcumin on gastric cancer cells: a proteomic study of molecular targets

Curcumin, a natural anticancer agent, has been shown to inhibit cell growth in a number of tumor cell lines and animal models. We examined the inhibition of curcumin on cell viability and its induction of apoptosis using different gastric cancer cell lines (BGC-823, MKN-45 and SCG-7901). 3-(4,5-dimethyl-thiazol-2-yl)-2-5-diphenyltetrazolium-bromide (MTT) assay showed that curcumin inhibited cell growth in a dose- (1, 5, 10 and 30 μM) and time- (24, 48, 72 and 96 h) dependent manner; analysis of Annexin V binding showed that curcumin induced apoptosis at the dose of 10 and 30 μM when the cells were treated for 24 and 48 h. As cancers are caused by dysregulation of various proteins, we investigated target proteins associated with curcumin by two-dimensional gel electrophoresis (2-DE) and MALDI-TOF-TOF mass spectrometer. BGC-823 cells were treated with 30 μM curcumin for 24 h and total protein was extracted for the 2-DE. In the first dimension of the 2-DE, protein samples (800 μg) were applied to immobilized pH gradient (IPG) strips (24 cm, pH 3-10, NL) and the isoelectric focusing (IEF) was performed using a step-wise voltage ramp; the second dimension was performed using 12.5% SDS-PAGE gel at 1 W constant power per gel. In total, 75 proteins showed significant changes over 1.5-fold in curcumin-treated cells compared to control cells (Student's t-test, p<0.05). Among them, 33 proteins were upregulated and 42 proteins downregulated by curcumin as determined by spot densitometry. 52 proteins with significant mascot scores were identified and implicated in cancer development and progression. Their biological function included cell proliferation, cycle and apoptosis (20%), metabolism (16%), nucleic acid processing (15%), cytoskeleton organization and movement (11%), signal transduction (11%), protein folding, proteolysis and translation (20%), and immune response (2%). Furthermore, protein-protein interacting analysis demonstrated the interaction networks affected by curcumin in gastric cancer cells. These data provide some clues for explaining the anticancer mechanisms of curcumin and explore more potent molecular targets of the drug expected to be helpful for the development of new drugs.

Expression of annexin-A1 and galectin-1 anti-inflammatory proteins and mRNA in chronic gastritis and gastric cancer

Objective. The anti-inflammatory proteins annexin-A1 and galectin-1 have been associated with tumor progression. This scenario prompted us to investigate the relationship between the gene and protein expression of annexin-A1 (ANXA1/AnxA1) and galectin-1 (LGALS1/Gal-1) in an inflammatory gastric lesion as chronic gastritis (CG) and gastric adenocarcinoma (GA) and its association with H. pylori infection. Methods. We analyzed 40 samples of CG, 20 of GA, and 10 of normal mucosa (C) by the quantitative real-time PCR (qPCR) technique and the immunohistochemistry assay. Results. High ANXA1 mRNA expression levels were observed in 90% (36/40) of CG cases (mean relative quantification RQ = 4.26  ±  2.03) and in 80% (16/20) of GA cases (mean RQ = 4.38  ±  4.77). However, LGALS1 mRNA levels were high (mean RQ = 2.44  ±  3.26) in 60% (12/20) of the GA cases, while low expression was found in CG (mean RQ = 0.43 ± 3.13; P < 0.01). Normal mucosa showed modest immunoreactivity in stroma but not in epithelium, while stroma and epithelium displayed an intense immunostaining in CG and GA for both proteins. Conclusion. These results have provided evidence that galectin-1 and mainly annexin-A1 are overexpressed in both gastritis and gastric cancer, suggesting a strong association of these proteins with chronic gastric inflammation and carcinogenesis.

Identification of differentially expressed genes in gastric cancer by high density cDNA microarray

The identification of molecular markers for diagnosis, treatment, and prognosis is a significant issue in the management of patients with gastric cancer. We compared the expression profiles of 23 gastric cancers and 22 normal gastric tissues using cDNA microarrays. We divided the samples into two sets, 11 pairs as a training set and 12 unpaired gastric cancer and 11 unpaired normal gastric tissues as a test set. We selected significant genes in the training set and validated the significance of the genes in the test set. We obtained 238 classifier genes that showed a maximum cross-validation probability and clear hierarchical clustering pattern in the training set, and showed excellent class prediction probability in the independent test set. The classifier genes consisted of known genes related to the biological features of cancer and 28% unknown genes. We obtained genome-wide molecular signatures of gastric cancer, which provides preliminary exploration data for the pathophysiology of gastric cancer.

Annexin A1 is associated with gastric cancer survival and promotes gastric cancer cell invasiveness through the formyl peptide receptor/extracellular signal-regulated kinase/integrin beta-1-binding protein 1 pathway

BACKGROUND

Annexin A1 (AnxA1) has been well-known as a glucocorticoid-regulated anti-inflammatory protein, and it is implicated in tumorigenesis in a tumor type-specific pattern. However, the role of AnxA1 in gastric cancer (GC) is indeterminate, and the underlying mechanism is not clear. The purpose of this study was to evaluate the prognostic significance and associated mechanism of AnxA1 in GC.

METHODS

Immunohistochemical staining was employed to analyze 118 GC patients. Both AnxA1 gain-of-function and loss-of-function approaches were performed in GC cells. Western blotting and reverse-transcription polymerase chain reaction were used for assessment of the AnxA1 regulation mechanism in GC cells. An intraperitoneal inoculation model in severe combined immunodeficient mice was used for an in vivo assay.

RESULTS

High AnxA1 expression was significantly associated with peritoneal metastasis (P = .009) and serosal invasion (P = .044). Cox multivariate analysis showed that high AnxA1 expression was an independent risk factor for poor overall survival in GC patients (P = .037). AnxA1 expression positively correlated with invasiveness of human GC cells both in vitro and in vivo. AnxA1 could regulate the GC cell invasion through the formyl peptide receptor (FPR)/extracellular signal-regulated kinase/integrin beta-1-binding protein pathway, and all 3 FPRs (FPR1 through FPR3) were involved in the regulation process.

CONCLUSIONS

High AnxA1 expression was associated with more serosal invasion, more peritoneal metastasis, and poorer overall survival in GC patients. The current study demonstrated a novel mechanism involving FPRs, extracellular signal-regulated kinases 1 and 2, and integrin beta-1-binding protein 1 by which AnxA1 regulated GC cell invasion.

Downregulation of PCDH9 predicts prognosis for patients with glioma

Recent evidence has indicated that biological markers are essential in estimating the prognosis of patients with gliomas. The aim of this study was to determine the status and clinical significance of a novel tumor suppressor, PCDH9 (protocadherin 9) in glioma using tissue microarrays and immunohistochemistry. Normal brain tissue showed strong positive immunostaining for PCDH9, but this was downregulated in the primary cerebral glial tumor samples (51.7%). Loss of PCDH9 expression was associated significantly with a higher histological grade. Survival analysis demonstrated that patients with PCDH9-negative tumors had significantly shorter survival times than those with PCDH9-positive tumors and that PCDH9 was an independent prognostic factor. Our results suggest that PCDH9 might function as a tumor suppressor during cancer development and progression and could be regarded as a useful biomarker for predicting the outcome of patients with cerebral glial tumors.

Down-regulated SPARCL1 is associated with clinical significance in human gastric cancer

BACKGROUND

SPARC-like protein 1 (SPARCL1), a member of extracelluar matrix glycoprotein, is involved in many physiological functions.

METHODS

Tissue microarray (TMA) blocks were constructed based on 1,072 Chinese patients, containing both gastric cancer (GC) tissues and adjacent normal mucosa tissues. We analyzed the expression of SPARCL1 from both mRNA and protein level, using Real-time quantitative polymerase chain reaction (qRT-PCR), semi-quantitative PCR, immunohistochemistry (IHC), and Western blotting. Loss of heterozygosity analysis at the SPARCL1 gene locus was carried out using ten paired tumor and matched normal tissues.

RESULTS

SPARCL1 mRNA was significantly reduced in tumor specimens compared with normal tissues. Down-regulation of SPARCL1 protein was detected in 413 cases (38.7%) of 1,072 primary gastric tumor tissues. Kaplan-Meier survival curves demonstrated that SPARCL1-positive patients had better median survival time than SPARCL1-negative patients (59 months vs. 28 months, P = 0.001). Multivariate survival analysis revealed that SPARCL1 was an independent prognostic factor in gastric adenocarcinoma patients with no metastasis and well/moderately differentiated. The incidence of LOH for each individual marker was 12.5% (1/8) for D4S2462, 20% (2/10) for D4S2929, and 33.3% (3/9) for SPARCL1.

CONCLUSIONS

Our study revealed the clinical significance of SPARCL1 expression, providing a basis that the loss of SPARCL1 is a negative event in GC progression and prognosis. Furthermore, SPARCL1 protein might be considered to be a potential differentiation marker.

Advances in understanding the relationship between annexin A1 and gastrointestinal cancer

Annexin A1 is a member of the annexin family of calcium-dependent phospholipid-binding proteins and participates in many important life processes, such as cellular signal transduction, proliferation, differentiation and apoptosis. Recent studies have shown that the expression levels of annexin A1 vary among different tumor tissues and different tumor subtypes and may be associated with the development, invasion and metastasis of malignant tumors. Understanding the relationship between annexin A1 and tumors has important implications for the early diagnosis and treatment of tumors.

Up-regulated Annexin A1 expression in gastrointestinal cancer is associated with cancer invasion and lymph node metastasis

Annexin A1 (ANXA1) is a calcium-dependent phospholipid-linked protein, involved in anti-inflammatory effects, regulation of cellular differentiation, proliferation and apoptosis. In the present study, we investigated the expression of ANXA1 in gastric and colon cancer, and analyzed the relationship between ANXA1 expression and clinicopathological factors. ANXA1 mRNA expression in gastric and colon cancer tissues was not significantly changed compared to that in normal tissues. When ANXA1 protein expression was evaluated by immunohistochemical staining, ANXA1 expression was observed in 76 of 135 cases of gastric cancer (56.3%), and correlations were found between ANXA1 expression and depth of wall invasion (P<0.001), lymphatic invasion (P=0.023), venous invasion (P=0.002), lymph node metastasis (P=0.001) and UICC stage (P<0.001). Disease-specific survival rate was significantly lower in cases with ANXA1 expression compared to that in cases without (P=0.0053). In colon cancer, ANXA1 expression was detected in 61 of 210 cases (29.0%) and correlations were found with gender (P=0.038), lymphatic invasion (P=0.011), venous invasion (P=0.023), lymph node metastasis (P=0.042) and UICC stage (P=0.041). The disease-specific survival rate tended to be lower in cases with ANXA1 expression, although the differences were not statistically significant (P=0.6984). Our results indicate that up-regulated ANXA1 expression is involved in cancer invasion and lymph node metastasis. Furthermore, high levels of ANXA1 expression were implicated in poor prognosis of patients. ANXA1 may be applicable as a prognostic biomarker in gastric and colon cancer, and a potential target for treatment.