A Novel Role for Tissue Factor Pathway Inhibitor-2 in the Therapy of Human Esophageal Carcinoma

A Kunitz-type inhibitor from tick salivary glands: A promising novel antitumor drug candidate

Salivary glands are vital structures responsible for successful tick feeding. The saliva of ticks contains numerous active molecules that participate in several physiological processes. A Kunitz-type factor Xa (FXa) inhibitor, similar to the tissue factor pathway inhibitor (TFPI) precursor, was identified in the salivary gland transcriptome of Amblyomma sculptum ticks. The recombinant mature form of this Kunitz-type inhibitor, named Amblyomin-X, displayed anticoagulant, antiangiogenic, and antitumor properties. Amblyomin-X is a protein that inhibits FXa in the blood coagulation cascade and acts via non-hemostatic mechanisms, such as proteasome inhibition. Amblyomin-X selectively induces apoptosis in cancer cells and promotes tumor regression through these mechanisms. Notably, the cytotoxicity of Amblyomin-X seems to be restricted to tumor cells and does not affect non-tumorigenic cells, tissues, and organs, making this recombinant protein an attractive molecule for anticancer therapy. The cytotoxic activity of Amblyomin-X on tumor cells has led to vast exploration into this protein. Here, we summarize the function, action mechanisms, structural features, pharmacokinetics, and biodistribution of this tick Kunitz-type inhibitor recombinant protein as a promising novel antitumor drug candidate.

Possible Treatment Approaches of Sulfur Mustard-Induced Lung Disorders, Experimental and Clinical Evidence, an Updated Review

Sulfur mustard (SM) is one of the major potent chemical warfare that caused the death of victims in World War I and the Iraq-Iran conflict (1980-1988). The respiratory system is the main target of SM exposure and there are no definitive therapeutic modalities for SM-induced lung injury. The effects of the new pharmaceutical drugs on lung injury induced by SM exposure were summarized in this review. Literature review on PubMed, ScienceDirect, and Google Scholar databases was performed to find papers that reported new treatment approach on SM-exposure-induced injury in the respiratory system until October 2019. The search was restricted to sulfur mustard AND induced injury (in vitro studies, animal experiments, and clinical trials) AND respiratory system OR lung, AND treatment in all fields. Two hundred and eighty-three relevant articles were identified that 97 retrieved articles were eligible and were included in the review. Some new pharmaceutical drugs have shown therapeutic potential in controlling various characteristics of lung injury due to SM exposure. Recent studies showed therapeutic effects of mucolytic drugs, non-steroidal drugs, and antibiotics on reducing lung inflammation, oxidative stress responses, and modulating of the immune system as well as improving of respiratory symptoms and pulmonary function tests. Studies on the therapeutic effects of new agents with amelioration or treatment of SM-induced lung injury were reviewed and discussed.

Toward an understanding of tissue factor pathway inhibitor-2 as a novel serodiagnostic marker for clear cell carcinoma of the ovary

AIMS

Tissue factor pathway inhibitor (TFPI)-2 has recently emerged as a serodiagnostic marker for patients with epithelial ovarian cancer (EOC), especially clear cell carcinoma (CCC). This review discusses the biological properties of TFPI-2 and why serum levels are elevated in CCC patients.

METHODS

A comprehensive literature search was conducted in PubMed up until March, 2021.

RESULTS

TFPI-2 is a Kunitz-type protease inhibitor and negatively regulates the enzymatic activities, such as plasmin. TFPI-2 has been characterized as a tumor suppressor gene and was frequently downregulated through promoter hypermethylation in various human cancers. In contrast, TFPI-2 was overexpressed only in CCC. TFPI-2 may be involved in the pathophysiology of CCC, possibly through regulation of coagulation system, stabilization of extracellular matrix (ECM), and induction of intracellular signal transduction. TFPI-2 suppresses tissue factor-induced hypercoagulation in a hypoxic environment. TFPI-2, secreted by CCC cells, platelets, and adjacent vascular endothelial cells, may suppress tumor growth and invasion through ECM remodeling. Nuclear TFPI-2 may suppress matrix metalloproteinase production via transcription factors and modulate caspase-mediated cell apoptosis. CCC cells may upregulate the TFPI-2 expression to adapt to survival in the demanding environment. TFPI-2 is secreted by CCC cells and enters the systemic circulation, resulting in elevated blood levels.

DISCUSSION

Serum TFPI-2 reflects the overexpression of TFPI-2 in CCC tissues and is a potential serodiagnostic marker. Further research is needed to explore the expression, clinical significance, biological function, and potential mechanism of TFPI-2 in CCC.

Tissue factor pathway inhibitor 2 is a potent kallikrein-related protease 12 inhibitor

The protease activities are tightly regulated by inhibitors and dysregulation contribute to pathological processes such as cancer and inflammatory disorders. Tissue factor pathway inhibitor 2 (TFPI-2) is a serine proteases inhibitor, that mainly inhibits plasmin. This protease activated matrix metalloproteases (MMPs) and degraded extracellular matrix. Other serine proteases are implicated in these mechanisms like kallikreins (KLKs). In this study, we identified for the first time that TFPI-2 is a potent inhibitor of KLK5 and 12. Computer modeling showed that the first Kunitz domain of TFPI-2 could interact with residues of KLK12 near the catalytic triad. Furthermore, like plasmin, KLK12 was able to activate proMMP-1 and -3, with no effect on proMMP-9. Thus, the inhibition of KLK12 by TFPI-2 greatly reduced the cascade activation of these MMPs and the cleavage of cysteine-rich 61, a matrix signaling protein. Moreover, when TFPI-2 bound to extracellular matrix, its classical localisation, the KLK12 inhibition was retained. Finally, TFPI-2 was downregulated in human non-small-cell lung tumour tissue as compared with non-affected lung tissue. These data suggest that TFPI-2 is a potent inhibitor of KLK12 and could regulate matrix remodeling and cancer progression mediated by KLK12.

Role of MicroRNAs in Treatment Response in Prostate Cancer

Prostate cancer (PCa) is the most common non-skin cancer in men worldwide, resulting in significant mortality and morbidity. Depending on the grade and stage of the cancer, patients may be given radiation therapy, hormonal therapy, or chemotherapy. However, more than half of these patients develop resistance to treatment, leading to disease progression and metastases, often with lethal consequences. MicroRNAs (miRNAs) are short, non-coding RNAs, which regulate numerous physiological as well as pathological processes, including cancer. miRNAs mediate their regulatory effect predominately by binding to the 3'-untranslated region (UTR) of their target mRNAs. In this review, we will describe the mechanisms by which miRNAs mediate resistance to radiation and drug therapy (i.e. hormone therapy and chemotherapy) in PCa, including control of apoptosis, cell growth and proliferation, autophagy, epithelial-to-mesenchymal transition (EMT), invasion and metastasis, and cancer stem cells (CSCs). Furthermore, we will discuss the utility of circulating miRNAs isolated from different body fluids of prostate cancer patients as non-invasive biomarkers of cancer detection, disease progression, and therapy response. Finally, we will shortlist the candidate miRNAs, which may have a role in drug and radioresistance, that could potentially be used as predictive biomarkers of treatment response.

Identification of Hyper-Methylated Tumor Suppressor Genes-Based Diagnostic Panel for Esophageal Squamous Cell Carcinoma (ESCC) in a Chinese Han Population

DNA methylation-based biomarkers were suggested to be promising for early cancer diagnosis. However, DNA methylation-based biomarkers for esophageal squamous cell carcinoma (ESCC), especially in Chinese Han populations have not been identified and evaluated quantitatively. Candidate tumor suppressor genes (N = 65) were selected through literature searching and four public high-throughput DNA methylation microarray datasets including 136 samples totally were collected for initial confirmation. Targeted bisulfite sequencing was applied in an independent cohort of 94 pairs of ESCC and normal tissues from a Chinese Han population for eventual validation. We applied nine different classification algorithms for the prediction to evaluate to the prediction performance. ADHFE1, EOMES, SALL1 and TFPI2 were identified and validated in the ESCC samples from a Chinese Han population. All four candidate regions were validated to be significantly hyper-methylated in ESCC samples through Wilcoxon rank-sum test (ADHFE1, P = 1.7 × 10^-3; EOMES, P = 2.9 × 10^-9; SALL1, P = 3.9 × 10^-7; TFPI2, p = 3.4 × 10^-6). Logistic regression based prediction model shown a moderately ESCC classification performance (Sensitivity = 66%, Specificity = 87%, AUC = 0.81). Moreover, advanced classification method had better performances (random forest and naive Bayes). Interestingly, the diagnostic performance could be improved in non-alcohol use subgroup (AUC = 0.84). In conclusion, our data demonstrate the methylation panel of ADHFE1, EOMES, SALL1 and TFPI2 could be an effective methylation-based diagnostic assay for ESCC.

Hypomethylation of tissue factor pathway inhibitor 2 in human placenta of preeclampsia

OBJECTIVES

To investigate the expression, DNA methylation status and its regulatory mechanism of tissue factor pathway inhibitor 2 (TFPI-2) in human placenta tissues of preeclampsia (PE).

MATERIAL AND METHODS

We studied the mRNA and protein expression and the promoter methylation levels of TFPI-2 in the PE placentas compared with those in the normal pregnant (NP) women. Quantitative real-time polymerase chain reaction, immunohistochemistry, western blot, and Sequenom MassARRAY were used for placenta tissue detection.

RESULTS

The expressions of TFPI-2 mRNA and protein were significantly elevated in the PE placentas when compared with those in the NP ones (P<0.05). Hypomethylation of the TFPI-2 promoter was detected both in PE patients and NP women, with a significant decrease in PE placentas (P=0.005). The methylation level was significantly decreased at CpG_6 (-168 to -167), CpG_15 (-98 to -97) and CpG_18.19 (-68 to -65) in PE patients than that in normal placentas (P<0.05). However, the expression of DNMT-1 didn't show significant difference between the two groups (P>0.05).

CONCLUSION

Over-expression of TFPI-2 and aberrant promoter mythylation status presented in the PE placentas, suggesting that epigenetic mechanism might contribute to the pathogenesis of PE.

Tissue factor pathway inhibitor-2 induced hepatocellular carcinoma cell differentiation

To investigate the effect of over-expression of tissue factor pathway inhibitor-2 (TFPI-2) on the differentiation of hepatocellular carcinoma (HCC) cells (Hep3B and HepG2). The TFPI-2 recombinant adenovirus (pAd-TFPI-2) was constructed using the pAdeasy-1 vector system. Transfected by pAd-TFPI-2, the cell proliferation of HCC cells was evaluated by CCK-8 assay, flow cytometry was used to detect cell apoptosis and CD133 expression. Real-time PCR and Western blot were used to detect the expression levels of markers of hepatocellular cancer stem cells (CSC) and hepatocytes. The over-expression of TFPI-2 significantly suppressed cell proliferation, induced apoptosis, and dramatically decreased the percentage of CD133 cells, which was considered as CSC in HCC. Real-time PCR and Western blot showed that the expression of markers of CSC in Hep3B cells and HepG2 cells infected with pAd-TFPI-2 was markedly lower than those of the control group (P < 0.05), while the expression of markers of hepatocytes was significantly increased (P < 0.05). Hence, TFPI-2 could induce the differentiation of hepatocellular carcinoma cells into hepatocytes, and is expected to serve as a novel way for the treatment of HCC.

Promoter hypermethylation and silencing of tissue factor pathway inhibitor-2 in oral squamous cell carcinoma

Background

The treatment of oral squamous cell carcinoma (OSCC) following early detection is associated with good outcomes. Therefore, the survival and prognosis of OSCC patients could be hugely improved by identifying reliable biomarkers for the early diagnosis of the disease. Our previous methylation microarray analysis results have suggested that the gene encoding tissue factor pathway inhibitor-2 (TFPI-2) is a potential clinical predictor as well as a key regulator involved in OSCC malignancy.

Methods

Methylation of the TFPI-2 promoter in oral tissue specimens was evaluated by bisulfite sequencing assay, quantitative methylation-specific PCR, and pyrosequencing assay. The differences in methylation levels among the groups were compared using the Mann–Whitney U test. The area under the receiver operating characteristic curve (AUROC) was used to evaluate the discrimination ability for detecting OSCC. Cellular TFPI-2 expression was analyzed by quantitative reverse-transcription PCR before and after treatment with 5′-aza-2′-deoxycytidine and trichostatin A, to confirm whether TFPI-2 was epigenetically silenced in OSCC cells. We investigated whether TFPI-2 plays a role as a tumor suppressor by establishing TFPI-2-overexpressing OSCC cells and subjecting them to in vitro cellular proliferation, migration, and invasion assays, as well as an in vivo metastasis assay.

Results

TFPI-2 was hypermethylated in OSCC tissues versus normal oral tissues (P < 0.0001), with AUROC = 0.91, when using a pyrosequencing assay to quantify the methylation level. TFPI-2 silencing in OSCC was regulated by both DNA methylation and chromatin histone modification. Restoration of TFPI-2 counteracted the invasiveness of OSCC by inhibiting the enzymatic activity of matrix metalloproteinase-2, and consequently interfered with OSCC metastasis in vivo.

Conclusions

Our data suggest strongly that TFPI-2 is a down-regulated tumor suppressor gene in OSCC, probably involving epigenetic silencing mechanisms. The loss of TFPI-2 expression is a key event for oral tumorigenesis, especially in the process of tumor metastasis.

Beneficial role of overexpression of TFPI-2 on tumour progression in human small cell lung cancer

Tissue factor pathway inhibitor-2 (TFPI-2) is a potent inhibitor of plasmin, a protease which is involved in tumour progression by activating (MMPs). This therefore makes TFPI-2 a potential inhibitor of invasiveness and the development of metastases. In this study, low levels of TFPI-2 expression were found in 65% of patients with small cell lung cancer (SCLC), the most aggressive type of lung cancer. To study the impact of TFPI-2 in tumour progression, TFPI-2 was overexpressed in NCI-H209 SCLC cells which were orthotopically implanted in nude mice. Investigations showed that TFPI-2 inhibited lung tumour growth. Such inhibition could be explained in vitro by a decrease in tumour cell viability, blockade of G1/S phase cell cycle transition and an increase in apoptosis shown in NCI-H209 cells expressing TFPI-2. We also demonstrated that TFPI-2 upregulation in NCI-H209 cells decreased MMP expression, particularly by downregulating MMP-1 and MMP-3. Moreover, TFPI-2 inhibited phosphorylation of the MAPK signalling pathway proteins involved in the induction of MMP transcripts, among which MMP-1 was predominant in SCLC tissues and was inversely expressed with TFPI-2 in 35% of cases. These results suggest that downregulation of TFPI-2 expression could favour the development of SCLC.

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The Tissue Factor Pathway Inhibitor-2 inhibits small cell lung cancer growth

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Monitoring of small cell lung cancer growth in a mouse orthotopic model by imaging

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Increasing information on the role of TFPI-2 in human lung tumour cells

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Increasing information on TFPI-2 and protease expression in human tissue samples

Inhibition of the ecto-beta subunit of F1F0-ATPase inhibits proliferation and induces apoptosis in acute myeloid leukemia cell lines

BACKGROUND

Leukemia, a heterogeneous clonal disorder of hematopoietic progenitor cells, presents a world-wide health problem, especially in childhood. F1F0 ATPase, an inner mitochondrial enzyme, is expressed on the plasma membrane of tumor cells, and its inhibition induces both anti-angiogenic and anti-tumorigenic activity.

METHODS

Monoclonal Antibody (McAb) against ATPase was produced by polyethylene glycol-mediated fusions and screened by ELISA. Proliferation, cell cycle and apoptosis of cells were analyzed when the surface ATPase of cells was blockaded with McAb.

RESULTS

We detected cell-membrane expression of the F1F0 ATPase β subunit on 0.1% to 56% of the 11 cell lines derived from leukemia, including acute myeloid leukemia (AML). We produced a monoclonal antibody, McAb7E10, which recognizes both the native and recombinant ATPase β subunit, with a dissociation constant (KD) of 3.26E-10. We demonstrate that McAb7E10 binds to ATPase at the cell surface, where it is able to inhibit ATP synthesis. McAb7E10 significantly inhibited proliferation of AML cell lines in vitro: the relative inhibitory rates of 50 μg/mL McAb7E10 treated MV4-11and HL-60 cells were 69.6% and 81.9% respectively. Cell cycle analysis indicated that McAb7E10 significantly induced apoptosis in MV4-11 and HL-60 cells: the relative rates of apoptosis in 5, 10 and 50ug/mL McAb7E10 treated MV4-11 cells was 3.6 ± 0.83%, 8.4 ± 1.69% and 17.3 ± 2.56% compared to 1.5% ± 0.85% in mouse IgG treated cells (p < 0.01). The relative rate of apoptosis in 5, 10 and 50ug/mL McAb7E10 treated HL-60 cells was 5.5 ± 2.37%, 11.3 ± 3.62% and 19.9 ± 3.31% compared to 1.56% ± 0.97% in mouse IgG treated cells (p < 0.01). Annexin V staining demonstrated that the relative apoptotic rates in 50 μg/mL McAb7E10 treated MV4-11 and HL-60 cells were 50.5% ± 7.04% and 32.9% ± 4.52%, respectively, significantly higher than IgG control antibody treated cells were 21.9% ± 3.11% and 15.3% ± 3.95%, p < 0.01.

CONCLUSIONS

These findings indicate that ectopic expression of ATPase β subunit may be a tumor-associated antigen in hematological malignancies. The F1F0 ATPase β subunit provides a potential target for immunotherapy in AML and hematological malignancies.

TFPI-2 downregulates multidrug resistance protein in 5-FU-resistant human hepatocellular carcinoma BEL-7402/5-FU cells

Tissue factor pathway inhibitor-2 (TFPI-2) is known to induce apoptosis and to suppress tumor metastasis in several types of cancer cells. However, there is little known about its reversal effect on chemoresistant tumor cells. This study investigated the effect of TFPI-2 in 5-fluorouracil (5-FU)-resistant human hepatocellular cancer BEL-7402/5-FU cells in vitro. We constructed TFPI-2 overexpression BEL-7402/5-FU cell lines and explored resistance index (RI) of 5-FU, function of the P-glycoprotein (P-gp) efflux pump, and the mRNA and protein expression of drug resistance gene, including multidrug resistance gene (MDR1), lung-resistance protein (LRP), multidrug resistance-associated protein (MRP1), glutathione-S-transferase-π (GST-π), excision repair cross-complementing gene 1 (ERCC1), and p38 phosphorylation. We found that TFPI-2 improved the RI of 5-FU and inhibited P-gp function. Western blotting and real-time PCR revealed that TFPI-2 also decreased mRNA and protein expression of MDR1, LRP, MRP1, GST-π, and ERCC1, whereas p38 phosphorylation was increased. We considered that TFPI-2 reduces 5-FU resistance in BEL-7402/5-FU cells, and the mechanism appears to involve p38-mediated downregulation of drug resistance gene expression such as MDR1, LRP, MRP1, GST-π, and ERCC1.

Actions of the Kunitz-type serine protease inhibitor Amblyomin-X on VEGF-A-induced angiogenesis

Amblyomin-X is a Kunitz-type serine protease inhibitor (Kunitz-type SPI) designed from the cDNA library of the Amblyomma cajennense tick, which displays in vivo anti-tumor activities. Here, the mechanisms of actions of Amblyomin-X in vascular endothelial growth factor A (VEGF-A)-induced angiogenesis were characterized. Topical application of Amblyomin-X (10 or 100 ng/10 μl; each 48 h) inhibited VEGF-A-induced (10 ng/10 μl; each 48 h) angiogenesis in the dorsal subcutaneous tissue in male Swiss mice. Moreover, similar effect was observed in the VEGF-A-induced angiogenesis in the chicken chorioallantoic membrane (CAM). Additional in vitro assays in t-End cells showed that Amblyomin-X treatment delayed the cell cycle, by maintaining them in G0/G1 phase, and inhibited cell proliferation and adhesion, tube formation and membrane expression of the adhesion molecule platelet-endothelial cell adhesion molecule-1 (PECAM-1), regardless of mRNA synthesis. Together, results herein reveal the role of Kunitz-type SPI on in vivo VEGF-A-induced angiogenesis, by exerting modulatory actions on endothelial cell proliferation and adhesion, especially on membrane expression of PECAM-1. These data provide further mechanisms of actions of Kunitz-type SPI, corroborating their relevance as scientific tools in the design of therapeutic molecules.

Reduced expression of tissue factor pathway inhibitor-2 contributes to apoptosis and angiogenesis in cervical cancer

Background

Tissue factor pathway inhibitor-2 (TFPI-2) is an extracellular matrix associated broad-spectrum Kunitz-type serine proteinase inhibitor. Recently, down regulation of TFPI-2 was suggested to be involved in tumor invasion and metastasis in some cancers.

Methods

This study involved 12 normal cervical squamous epithelia, 48 cervical intraepithelial neoplasia (CIN), and 68 cervical cancer. The expression of TFPI-2, Ki-67 and vascular endothelial growth factor (VEGF) were investigated by immunohistochemistry staining. The apoptolic index(AI) was determined with an in situ end-labeling assay(TUNEL). And the marker of CD34 staining was used as an indicator of microvessel density (MVD).

Results

TFPI-2 expression has a decreasing trend with the progression of cervical cancer and was significantly correlated with FIGO stage, lymph node metastasis and HPV infection. In addition, there were significant positive correlations between the grading of TFPI-2 expression and AI(P = 0.004). In contrast, the expression of TFPI-2 and VEGF or MVD was negatively correlated (both p < 0.001). However, we did not establish any significant correlation between Ki-67 and TFPI-2 expression in cervical cancer.

Conclusions

The results suggested that the expression of TFPI-2 had a decreasing trend with tumor progression of cervical cancer. There was a close association between the expression of TFPI-2 and tumor cell apoptosis and angiogenesis in patients with cervical cancer. TFPI-2 may play an inhibitive role during the development of cervical cancer.

Promoter of TFPI-2 is hypermethylated in Chinese pediatric acute myeloid leukemia

Human tissue factor pathway inhibitor-2 (TFPI-2) has been implicated as a metastasis-associated gene in many types of tumors. In this study, we investigated whether TFPI-2 was inactivated epigenetically in pediatric acute myeloid leukemia (AML). Methylation status was investigated by methylation-specific polymerase chain reaction and bisulfate genomic sequencing. TFPI-2 was aberrantly methylated in 50% (3/6) of AML cell lines. Aberrant methylation of TFPI-2 promoter was detected in 71.6% (48/67) of the Chinese pediatric AML patients. TFPI-2 transcript was significantly lower in AML group compared with controls (3.44 vs. 32.8, P<0.001). Patients with methylated TFPI-2 gene had significantly lower TFPI-2 transcript than those patients without methylated TFPI-2 (P=0.04). Promoter hypermethylation of TFPI-2 is frequent and specific event in pediatric AML.

ATP synthase ecto-α-subunit: a novel therapeutic target for breast cancer

Background

Treatment failure for breast cancer is frequently due to lymph node metastasis and invasion to neighboring organs. The aim of the present study was to investigate invasion- and metastasis-related genes in breast cancer cells in vitro and in vivo. Identification of new targets will facilitate the developmental pace of new techniques in screening and early diagnosis. Improved abilities to predict progression and metastasis, therapeutic response and toxicity will help to increase survival of breast cancer patients.

Methods

Differential protein expression in two breast cancer cell lines, one with high and the other with low metastatic potential, was analyzed using two-dimensional liquid phase chromatographic fractionation (Proteome Lab PF 2D system) followed by matrix-assisted laser desorption/time-of-flight mass spectrometry (MALDI-TOF/MS).

Results

Up regulation of α-subunit of ATP synthase was identified in high metastatic cells compared with low metastatic cells. Immunohistochemical analysis of 168 human breast cancer specimens on tissue microarrays revealed a high frequency of ATP synthase α-subunit expression in breast cancer (94.6%) compared to normal (21.2%) and atypical hyperplasia (23%) breast tissues. Levels of ATP synthase expression levels strongly correlated with large tumor size, poor tumor differentiation and advanced tumor stages (P < 0.05). ATP synthase α-subunit over-expression was detected on the surface of a highly invasive breast cancer cell line. An antibody against the ATP synthase α-subunit inhibited proliferation, migration and invasion in these breast cancer cells but not that of a non-tumor derived breast cell line.

Conclusions

Over-expression of ATP synthase α-subunit may be involved in the progression and metastasis of breast cancer, perhaps representing a potential biomarker for diagnosis, prognosis and a therapeutic target for breast cancer. This finding of this study will help us to better understand the molecular mechanism of tumor metastasis and to improve the screening, diagnosis, as well as prognosis and/or prediction of responses to therapy for breast cancer.

An novel role of sphingosine kinase-1 (SPHK1) in the invasion and metastasis of esophageal carcinoma

Background

Treatment failure for esophageal carcinoma is frequently due to lymph node metastasis and invasion to neighboring organs. The aim of the present study was to investigate invasion- and metastasis-related genes in esophageal carcinoma cells in vitro and in vivo.

Methods

A metastasis model using a Matrigel invasion clonal selection approach was employed to establish a highly invasive subline EC9706-P4 from the esophageal carcinoma cell (ESCC) line EC9706. The differentially expressed genes of the subline and the parental cells determined by gene microarrays were further analyzed by RT-PCR and Western blotting.

Results

We identified sphingosine kinase 1 (SPHK1) as an invasion and metastasis-related gene of esophageal cancer. SPHK1 was overexpressed in the EC9706-P4 subline with high invasive capacity. Among six ESCC lines tested, KYSE2 and KYSE30 cells showed the highest SPHK1 mRNA and protein expressions as well as the most invasive phenotype. By Western blotting, in 7/12 cases (58%), SPHK1 expression was higher in esophageal carcinomas than in the companion normal tissue. In 23/30 cases (76%), SPHK1 protein expression was upregulated in the tumors compared to matched normal tissue by immunohistochemistry (IHC). Esophageal carcinoma tissue microarray analysis indicated that SPHK1 expression correlated with the depth of tumor invasion (P < 0.0001) and lymph node metastasis (P = 0.016). By Kaplan-Meier analysis, strong SPHK1 expression was significantly associated with clinical failure (P < 0.01), suggesting the involvement of SPHK1 in aggressiveness of human esophageal carcinoma. SPHK1 overexpression significantly increased the invasiveness of EC9706 cells in vitro and also increased EC9706 cell growth and spontaneous metastasis in vivo, promoting significant increases in tumor growth, tumor burden and spontaneous lung metastasis in nude mice. SPHK1 expression significantly correlated with the expression of many EGFR pathway genes associated with invasion of cancer cells. SPHK1 protein expression also significantly correlated with the phosphorylation of EGFR.

Conclusion

In summary, our data implicate SPHK1 in the metastasis of esophageal cancer. Our study also identified downstream mediators of SPHK1 in esophageal cancer cells that may mediate enhanced malignant behavior, and several of these mediators may be useful as therapeutic targets.

MMP28 (epilysin) as a novel promoter of invasion and metastasis in gastric cancer

Background

The purpose of this study was to investigate invasion and metastasis related genes in gastric cancer.

Methods

The transwell migration assay was used to select a highly invasive sub-line from minimally invasive parent gastric cancer cells, and gene expression was compared using a microarray. MMP28 upregulation was confirmed using qRT-PCR. MMP28 immunohistochemistry was performed in normal and gastric cancer specimens. Invasiveness and tumor formation of stable cells overexpressing MMP28 were tested in vitro and in vivo.

Results

MMP28 was overexpressed in the highly invasive sub-cell line. Immunohistochemistry revealed MMP28 expression was markedly increased in gastric carcinoma relative to normal epithelia, and was significantly associated with depth of tumor invasion, lymph node metastasis and poorer overall survival. Ectopic expression of MMP28 indicated MMP28 promoted tumor cell invasion in vitro and increased gastric carcinoma metastasis in vivo.

Conclusions

This study indicates MMP28 is frequently overexpressed during progression of gastric carcinoma, and contributes to tumor cell invasion and metastasis. MMP28 may be a novel therapeutic target for prevention and treatment of metastases in gastric cancer.

Association of cyclin D1 gene polymorphisms with risk of esophageal squamous cell carcinoma in Kashmir Valley: a high risk area

Investigation of potential association of SNPs (G870A, rs9344; G1722C, rs678653) of cyclin D1 gene (CCND1) with susceptibility to esophageal squamous cell carcinoma (ESCC) in Kashmir valley (India). The study included 302 subjects comprising 151 ESCC cases and 151 controls. PCR-RFLP and direct sequencing were employed for genotyping. The G870A polymorphism, the individuals carrying GA + AA genotype was having 2.80-fold increased risk for development of ESCC (OR 2.8, 95% CI = 1.77-4.4; P = 0.0001) compared to GG genotype. Further a significantly higher risk was observed in individuals who consume >3 cups per day of salted tea (OR = 5.1; 95% CI = 1.6-16.7; P = 0.0016) and had smoking habits (OR = 6.3; 95% CI = 2.9-13.9; P = 0.0005). We also demonstrate for the first time in CCND1 1722 locus, the CC genotype was strongly associated with increased risk of developing ESCC (OR = 2.58; 95% CI = 1.61-4.15; P = 0.0001). In addition, the frequency of polymorphic C allele was also found to be higher in cases (OR = 1.92; 95% CI = 1.37-2.69; P = 0.0002). There appears to be an influence of CCND1 G870A/G1772C genotypes on genetic susceptibility to ESCC.

TFPI-2 is a putative tumor suppressor gene frequently inactivated by promoter hypermethylation in nasopharyngeal carcinoma

Background

Epigenetic silencing of tumor suppressor genes play important roles in NPC tumorgenesis. Tissue factor pathway inhibitor-2 (TFPI-2), is a protease inhibitor. Recently, TFPI-2 was suggested to be a tumor suppressor gene involved in tumorigenesis and metastasis in some cancers. In this study, we investigated whether TFPI-2 was inactivated epigenetically in nasopharyngeal carcinoma (NPC).

Methods

Transcriptional expression levels of TFPI-2 was evaluated by RT-PCR. Methylation status were investigated by methylation specific PCR and bisulfate genomic sequencing. The role of TFPI-2 as a tumor suppressor gene in NPC was addressed by re-introducing TFPI-2 expression into the NPC cell line CNE2.

Results

TFPI-2 mRNA transcription was inactivated in NPC cell lines. TFPI-2 was aberrantly methylated in 66.7% (4/6) NPC cell lines and 88.6% (62/70) of NPC primary tumors, but not in normal nasopharyngeal epithelia. TFPI-2 expression could be restored in NPC cells after demethylation treatment. Ectopic expression of TFPI-2 in NPC cells induced apoptosis and inhibited cell proliferation, colony formation and cell migration.

Conclusions

Epigenetic inactivation of TFPI-2 by promoter hypermethylation is a frequent and tumor specific event in NPC. TFPI-2 might be considering as a putative tumor suppressor gene in NPC.