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

Cancer-associated thrombosis: What about microRNAs targeting the tissue factor coagulation pathway?

Cancer patients are often diagnosed with venous thromboembolism (VTE), a cardiovascular disease that substantially decreases their quality of life and survival rate. Haemostasis in these patients is deregulated, which is reflected in the common presentation of a blood hypercoagulation state. Despite the inconsistent results, existing evidence suggests that the expression of microRNAs (miRNAs) is deregulated in the context of venous thrombogenesis in the general population. However, few miRNAs are known to be linked to cancer-associated VTE due to the lack of studies with oncological patients. Parallelly, coagulation factor III, also known as tissue factor (TF), tissue factor pathway inhibitor 1 (TFPI1) and tissue factor pathway inhibitor 2 (TFPI2) have been proposed to have a central role in cancer-associated VTE and tumour progression. Yet, contrary to what was expected, the role of miRNAs targeting the TF coagulation pathway (or extrinsic coagulation pathway) is poorly explored in cancer-induced thrombogenesis. In this review, in addition to miRNAs implicated in VTE, TF and TFPI1/2-targeting miRNAs were revised. Future studies should clarify the implications of these non-coding RNAs in tumour coagulome.

The Tissue Factor Pathway in Cancer: Overview and Role of Heparan Sulfate Proteoglycans

Historically, the only focus on tissue factor (TF) in clinical pathophysiology has been on its function as the initiation of the extrinsic coagulation cascade. This obsolete vessel-wall TF dogma is now being challenged by the findings that TF circulates throughout the body as a soluble form, a cell-associated protein, and a binding microparticle. Furthermore, it has been observed that TF is expressed by various cell types, including T-lymphocytes and platelets, and that certain pathological situations, such as chronic and acute inflammatory states, and cancer, may increase its expression and activity. Transmembrane G protein-coupled protease-activated receptors can be proteolytically cleaved by the TF:FVIIa complex that develops when TF binds to Factor VII (PARs). The TF:FVIIa complex can activate integrins, receptor tyrosine kinases (RTKs), and PARs in addition to PARs. Cancer cells use these signaling pathways to promote cell division, angiogenesis, metastasis, and the maintenance of cancer stem-like cells. Proteoglycans play a crucial role in the biochemical and mechanical properties of the cellular extracellular matrix, where they control cellular behavior via interacting with transmembrane receptors. For TFPI.fXa complexes, heparan sulfate proteoglycans (HSPGs) may serve as the primary receptor for uptake and degradation. The regulation of TF expression, TF signaling mechanisms, their pathogenic effects, and their therapeutic targeting in cancer are all covered in detail here.

Transcriptomic Analysis of Canine Osteosarcoma from a Precision Medicine Perspective Reveals Limitations of Differential Gene Expression Studies

Despite significant advances in cancer diagnosis and treatment, osteosarcoma (OSA), an aggressive primary bone tumor, has eluded attempts at improving patient survival for many decades. The difficulty in managing OSA lies in its extreme genetic complexity, drug resistance, and heterogeneity, making it improbable that a single-target treatment would be beneficial for the majority of affected individuals. Precision medicine seeks to fill this gap by addressing the intra- and inter-tumoral heterogeneity to improve patient outcome and survival. The characterization of differentially expressed genes (DEGs) unique to the tumor provides insight into the phenotype and can be useful for informing appropriate therapies as well as the development of novel treatments. Traditional DEG analysis combines patient data to derive statistically inferred genes that are dysregulated in the group; however, the results from this approach are not necessarily consistent across individual patients, thus contradicting the basis of precision medicine. Spontaneously occurring OSA in the dog shares remarkably similar clinical, histological, and molecular characteristics to the human disease and therefore serves as an excellent model. In this study, we use transcriptomic sequencing of RNA isolated from primary OSA tumor and patient-matched normal bone from seven dogs prior to chemotherapy to identify DEGs in the group. We then evaluate the universality of these changes in transcript levels across patients to identify DEGs at the individual level. These results can be useful for reframing our perspective of transcriptomic analysis from a precision medicine perspective by identifying variations in DEGs among individuals.

Hemostatic Biomarkers and Cancer Prognosis: Where Do We Stand?

Cancer patients are characterized by hypercoagulable state and an increased rate of thrombotic events, the most common being venous thromboembolism. Several hemostatic pathways that are significantly implicated in mechanisms of thromboembolic disease are also involved in growth, invasion, and metastatic spread of malignant cells as well in tumor-induced neo-angiogenesis. This close connection between cancer and the hemostatic system has prompted numerous studies on the role of alterations in the level plasma biomarkers of the different compartments of hemostasis in predicting cancer prognosis. In this review, we collect the results of several exemplificative studies that have evaluated clotting activation biomarkers in relation to different cancer outcomes with a final emphasis on current research and forthcoming directions in this field.

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.

Preparation of FA-targeted magnetic nanocomposites co-loading TFPI-2 plasmid and cis-platinum and its targeted therapy effects on nasopharyngeal carcinoma

The majority of patients diagnosed with nasopharyngeal carcinoma (NPC) present with advanced-stage disease. The main treatment for these patients is concurrent chemoradiotherapy, which has various side effects. To improve the therapeutic effects and reduce the side effects of NPC chemoradiotherapy, we constructed a multifunctional folic acid (FA)-targeted magnetic nanocomposite codelivering tissue factor pathway inhibitor-2 (TFPI-2) and cisplatin (CDDP). This novel nanocomposite (FA-MNP/CDDP/TFPI-2) was obtained by amidation and electrostatic adsorption between FA-methoxypolyethylene glycol-polyethyleneimine (FA-MPEG-PEI) containing the TFPI-2 plasmid and magnetic nanoparticles modified by aldehyde sodium alginate loaded with CDDP. Transmission electron microscopy (TEM) images showed that the size of the individual magnetite particle core was approximately 11.5 nm. The structure and composition of the nanocomposites were identified and examined by ¹H nuclear magnetic resonance (NMR) spectroscopy and ultraviolet (UV) spectrophotometry. The fluorescence analysis, Prussian blue iron staining, magnetic resonance (MR) imaging and whole-body fluorescence imaging results demonstrated that FA-MNP/CDDP/TFPI-2 showed high gene transfection efficiency and could target tumor cells via folate receptor (FR)-mediated delivery. The codelivery analysis showed that the obtained FA-MNP/CDDP/TFPI-2 composite could cause significantly more apoptosis than treatment with CDDP or TFPI-2 alone. The results showed that the FA-MNP/CDDP/TFPI-2 composites were successfully synthesized and indicated to be a specific molecular target for the FR with significant inhibitory effects on the growth of HNE-1 cells.

Tissue-specific usage of transposable element-derived promoters in mouse development

BACKGROUND

Transposable elements (TEs) are a significant component of eukaryotic genomes and play essential roles in genome evolution. Mounting evidence indicates that TEs are highly transcribed in early embryo development and contribute to distinct biological functions and tissue morphology.

RESULTS

We examine the epigenetic dynamics of mouse TEs during the development of five tissues: intestine, liver, lung, stomach, and kidney. We found that TEs are associated with over 20% of open chromatin regions during development. Close to half of these accessible TEs are only activated in a single tissue and a specific developmental stage. Most accessible TEs are rodent-specific. Across these five tissues, 453 accessible TEs are found to create the transcription start sites of downstream genes in mouse, including 117 protein-coding genes and 144 lincRNA genes, 93.7% of which are mouse-specific. Species-specific TE-derived transcription start sites are found to drive the expression of tissue-specific genes and change their tissue-specific expression patterns during evolution.

CONCLUSION

Our results suggest that TE insertions increase the regulatory potential of the genome, and some TEs have been domesticated to become a crucial component of gene and regulate tissue-specific expression during mouse tissue development.

Combination of RERG and ZNF671 methylation rates in circulating cell-free DNA: A novel biomarker for screening of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a prevalent malignancy in Southeast Asia, hence, identifying easily detectable biomarkers for NPC screening is essential for better diagnosis and prognosis. Using genome-wide and targeted analyses based on next-generation sequencing approaches, we previously showed that gene promoters are hypermethylated in NPC tissues. To confirm whether DNA methylation rates of genes could be used as biomarkers for NPC screening, 79 histologically diagnosed NPC patients and 29 noncancer patients were recruited. A convenient quantitative analysis of DNA methylation using real-time PCR (qAMP) was carried out, involving pretreatment of tissue DNA, and circulating cell-free DNA (ccfDNA) from nonhemolytic plasma, with methylation-sensitive and/or methylation-dependent restriction enzymes. The qAMP analyses revealed that methylation rates of RERG, ZNF671, ITGA4, and SHISA3 were significantly higher in NPC primary tumor tissues compared to noncancerous tissues, with sufficient diagnostic accuracy of the area under receiver operating characteristic curves (AUC). Interestingly, higher methylation rates of RERG in ccfDNA were statistically significant and yielded a very good AUC; however, those of ZNF671, ITGA4, and SHISA3 were not significant. Furthermore, the combination of methylation rates of RERG and ZNF671 in ccfDNA showed higher diagnostic accuracy than either of them individually. In conclusion, the methylation rates of specific genes in ccfDNA can serve as novel biomarkers for early detection and screening of NPC.

Detection and Analysis of RNAs Expression Profile for Methylated Candidate Tumor Suppressor Genes in Nasopharyngeal Carcinoma

BACKGROUND

DNA methylation, which acts as an expression regulator for multiple Tumor Suppressor Genes (TSGs), is believed to play an important role in Nasopharyngeal Carcinoma (NPC) development.

METHODS

We compared the effects of 5-aza-2-deoxycytidine (decitabine, DAC) on gene expression using RNA sequencing in NPC cells.

RESULTS

We analyzed Differentially Expressed Genes (DEGs) in NPC cells using DAC demethylation treatment and found that 2182 genes were significantly upregulated (≥ 2-fold change), suggesting that they may play a key role in cell growth, proliferation, development, and death. For data analysis, we used the Gene Ontology database and pathway enrichment analysis of the DEGs to discover differential patterns of DNA methylation associated with changes in gene expression. Furthermore, we evaluated 74 methylated candidate TSGs from the DEGs in NPC cells and summarized these genes in several important signaling pathways frequently disrupted by promoter methylation in NPC tumorigenesis.

CONCLUSION

Our study analyzes the DEGs and identifies a set of genes whose promoter methylation in NPC cells is reversed by DAC. These genes are potential substrates of DNMT inhibitors and may serve as tumor suppressors in NPC cells.

Increased placental expression of Placental Protein 5 (PP5) / Tissue Factor Pathway Inhibitor-2 (TFPI-2) in women with preeclampsia and HELLP syndrome: Relevance to impaired trophoblast invasion?

INTRODUCTION

Placental Protein 5 (PP5)/Tissue Factor Pathway Inhibitor-2 (TFPI-2) is an extracellular matrix-associated protein mainly expressed by the syncytiotrophoblast that may regulate trophoblast invasion. Our aim was to study placental PP5/TFPI-2 expression and its relation to placental pathology in various forms of preeclampsia and HELLP syndrome.

METHODS

Placental and maternal blood specimens were collected at the time of delivery from the same women in the following groups: 1) early controls; 2) early preeclampsia; 3) early preeclampsia with HELLP syndrome; 4) late controls; and 5) late preeclampsia. After histopathological examination, placental specimens were immunostained with polyclonal anti-PP5/TFPI-2 antibody on Western blot and tissue microarray immunohistochemistry. Placental PP5/TFPI-2 immunoscores were assessed manually and with a semi-automated method. Maternal sera were immunoassayed for PP5/TFPI-2.

RESULTS

PP5/TFPI-2 was localized to the cytoplasm of syncytiotrophoblast. Manual and semi-automated PP5/TFPI-2 immunoscores were higher in early preeclampsia with or without HELLP syndrome but not in late preeclampsia than in respective controls. In patients with preeclampsia, the correlation of placental PP5/TFPI-2 expression with maternal vascular malperfusion score of the placenta was positive while it was negative with birthweight and placental weight. Maternal serum PP5/TFPI-2 concentration was higher in early preeclampsia and it tended to be higher in early preeclampsia with HELLP syndrome than in early controls.

DISCUSSION

Our findings suggest that an increased placental PP5/TFPI-2 expression may be associated with abnormal placentation in early preeclampsia, with or without HELLP syndrome.

Inflammation and cancer

Infection and inflammation account for approximately 25% of cancer-causing factors. Inflammation-related cancers are characterized by mutagenic DNA lesions, such as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-nitroguanine. Our previous studies demonstrated the formation of 8-oxodG and 8-nitroguanine in the tissues of cancer and precancerous lesions due to infection (e.g., Opisthorchis viverrini-related cholangiocarcinoma, Schistosoma haematobium-associated bladder cancer, Helicobacter pylori-infected gastric cancer, human papillomavirus-related cervical cancer, Epstein-Barr virus-infected nasopharyngeal carcinoma) and pro-inflammatory factors (e.g., asbestos, nanomaterials, and inflammatory diseases such as Barrett's esophagus and oral leukoplakia). Interestingly, several of our studies suggested that inflammation-associated DNA damage in cancer stem-like cells leads to cancer development with aggressive clinical features. Reactive oxygen/nitrogen species from inflammation damage not only DNA but also other biomacromolecules, such as proteins and lipids, resulting in their dysfunction. We identified oxidatively damaged proteins in cancer tissues by 2D Oxyblot followed by MALDI-TOF/TOF. As an example, oxidatively damaged transferrin released iron ion, which may mediate Fenton reactions and generate additional reactive oxygen species. Dysfunction of anti-oxidative proteins due to this damage might increase oxidative stress. Such damage in biomacromolecules may form a vicious cycle of oxidative stress, leading to cancer development. Epigenetic alterations such as DNA methylation and microRNA dysregulation play vital roles in carcinogenesis, especially in inflammation-related cancers. We examined epigenetic alterations, DNA methylation and microRNA dysregulation, in Epstein-Barr virus-related nasopharyngeal carcinoma in the endemic area of Southern China and found several differentially methylated tumor suppressor gene candidates by using a next-generation sequencer. Among these candidates, we revealed higher methylation rates of RAS-like estrogen-regulated growth inhibitor (RERG) in biopsy specimens of nasopharyngeal carcinoma more conveniently by using restriction enzyme-based real-time PCR. This result may help to improve cancer screening strategies. We profiled microRNAs of nasopharyngeal carcinoma tissues using microarrays. Quantitative RT-PCR analysis confirmed the concordant downregulation of miR-497 in cancer tissues and plasma, suggesting that plasma miR-497 could be used as a diagnostic biomarker for nasopharyngeal carcinoma. Chronic inflammation promotes genetic and epigenetic aberrations, with various pathogeneses. These changes may be useful biomarkers in liquid biopsy for early detection and prevention of cancer.

Inflammation and cancer

Infection and inflammation account for approximately 25% of cancer-causing factors. Inflammation-related cancers are characterized by mutagenic DNA lesions, such as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-nitroguanine. Our previous studies demonstrated the formation of 8-oxodG and 8-nitroguanine in the tissues of cancer and precancerous lesions due to infection (e.g., Opisthorchis viverrini-related cholangiocarcinoma, Schistosoma haematobium-associated bladder cancer, Helicobacter pylori-infected gastric cancer, human papillomavirus-related cervical cancer, Epstein-Barr virus-infected nasopharyngeal carcinoma) and pro-inflammatory factors (e.g., asbestos, nanomaterials, and inflammatory diseases such as Barrett's esophagus and oral leukoplakia). Interestingly, several of our studies suggested that inflammation-associated DNA damage in cancer stem-like cells leads to cancer development with aggressive clinical features. Reactive oxygen/nitrogen species from inflammation damage not only DNA but also other biomacromolecules, such as proteins and lipids, resulting in their dysfunction. We identified oxidatively damaged proteins in cancer tissues by 2D Oxyblot followed by MALDI-TOF/TOF. As an example, oxidatively damaged transferrin released iron ion, which may mediate Fenton reactions and generate additional reactive oxygen species. Dysfunction of anti-oxidative proteins due to this damage might increase oxidative stress. Such damage in biomacromolecules may form a vicious cycle of oxidative stress, leading to cancer development. Epigenetic alterations such as DNA methylation and microRNA dysregulation play vital roles in carcinogenesis, especially in inflammation-related cancers. We examined epigenetic alterations, DNA methylation and microRNA dysregulation, in Epstein-Barr virus-related nasopharyngeal carcinoma in the endemic area of Southern China and found several differentially methylated tumor suppressor gene candidates by using a next-generation sequencer. Among these candidates, we revealed higher methylation rates of RAS-like estrogen-regulated growth inhibitor (RERG) in biopsy specimens of nasopharyngeal carcinoma more conveniently by using restriction enzyme-based real-time PCR. This result may help to improve cancer screening strategies. We profiled microRNAs of nasopharyngeal carcinoma tissues using microarrays. Quantitative RT-PCR analysis confirmed the concordant downregulation of miR-497 in cancer tissues and plasma, suggesting that plasma miR-497 could be used as a diagnostic biomarker for nasopharyngeal carcinoma. Chronic inflammation promotes genetic and epigenetic aberrations, with various pathogeneses. These changes may be useful biomarkers in liquid biopsy for early detection and prevention of cancer.

Hemostatic biomarkers in cancer progression

Malignant disease is characterized by a hemostatic imbalance, usually shifted towards a procoagulant direction, and a high incidence of thrombotic complications. The mechanisms of hemostasis that are critically involved in thrombosis are also implicated in tumor progression, angiogenesis, and metastatic spread. As there is a close relationship between cancer and the clotting system, circulating biomarkers of activation of various hemostasis compartments (i.e. coagulation, fibrinolysis, platelets, endothelium, and other blood cells) have been extensively studied to predict cancer outcomes along with predicting the thrombotic risk. In this review, we will summarize the results of published studies and will focus on ongoing research and future directions of clotting activation bioproducts as biomarkers of cancer disease and progression.

MiR-616-3p modulates cell proliferation and migration through targeting tissue factor pathway inhibitor 2 in preeclampsia

OBJECTIVES

Despite improvements in diagnosis and treatment, preeclampsia (PE) continues to pose a significant risk of maternal and foetal morbidity and mortality if not addressed promptly. An increasing number of studies have suggested that tissue factor pathway inhibitor 2 (TFPI2) acts as a suppressor gene, possibly inhibiting multiple serine proteases affecting cell proliferation and migration. It plays an essential role in the occurrence and development of PE, but the pathogenesis remains unclear.

MATERIALS AND METHODS

In our research, we performed western blotting, immunohistochemistry and qPCR assays to investigate TFPI2 and miR-616-3p expression in preeclamptic placental tissues. Cell assays were performed in HTR-8/SVneo and JEG3 cell lines. Cell proliferation and migration events were investigated by MTT, EdU and transwell assays. In conjunction with bioinformatics analysis, luciferase reporter assays were performed to elucidate the mechanism by which miR-616-3p binds to TFPI2 mRNA.

RESULTS

We established that TFPI2 protein levels were significantly upregulated in PE placental tissues. In addition, we found that miR-616-3p binds specifically to the 3'-UTR region of TFPI2 mRNA. Furthermore, miR-616-3p knockdown or TFPI2 overexpression substantially impaired cell growth and migration, whereas miR-616-3p upregulation or TFPI2 knockdown stimulated cell proliferation and migration. This miR-616-3p/TFPI2 axis was also found to affect the epithelial-mesenchymal transition process in PE.

CONCLUSIONS

Our results demonstrated that TFPI2 plays a vital role in the progression of PE and might provide a prospective therapeutic strategy to mitigate the severity of the disorder.

Lysine‑specific demethylase 2 contributes to the proliferation of small cell lung cancer by regulating the expression of TFPI‑2

The present study aimed to investigate the effect of lysine‑specific demethylase 2 (LSD2) in small cell lung cancer (SCLC) and explore its underlying regulatory mechanism. Cell growth was tested by MTT assay and mRNA and protein expression was determined by quantitative polymerase chain reaction (q‑PCR) and western blot analysis, respectively. Chromatin immunoprecipitation (ChIP) was used to investigate the degree of H3K4me2 enrichment in the promoter region of tissue factor pathway inhibitor‑2 (TFPI‑2). SCLC tissues and cell lines presented significantly higher expression of LSD2 and DNA methyltransferase 3B (DNMT3B) and lower expression of TFPI‑2 compared with the controls. In H1417 cells LSD2 overexpression increased the mRNA and protein expression of DNMT3B, while inhibiting the mRNA and protein expression of TFPI‑2. Following transfection with short interfering (si) RNA‑DNMT3B, the expression of TFPI‑2 increased in H1417 cells. The results of ChIP demonstrated that compared with the controls, H3K4me1 enrichment in the TFPI‑2 promoter region was to a lower degree in the H1417 cells with LSD2 overexpression and a higher degree in the H1417 cells with LSD2 silencing. MTT assays revealed that LSD2 overexpression significantly promoted the growth of H69, DMS‑114 and H1417 cells, which was contradictory to the effect on LSD2 silencing. Compared with the LSD2 overexpression cells, SCLC cells with simultaneous overexpression of LSD2 and TFPI‑2 demonstrated a decreased proliferation. These results suggest that LSD2 achieves a promoting effect on SCLC by indirectly regulating TFPI‑2 expression through the mediation of DNMT3B expression or through the regulation of the demethylation of H3K4me1 in the promoter region of the TFPI‑2 gene.

NFκB Promotes Ovarian Tumorigenesis via Classical Pathways That Support Proliferative Cancer Cells and Alternative Pathways That Support ALDH+ Cancer Stem-like Cells

Understanding the mechanisms supporting tumor-initiating cells (TIC) is vital to combat advanced-stage recurrent cancers. Here, we show that in advanced ovarian cancers NFκB signaling via the RelB transcription factor supports TIC populations by directly regulating the cancer stem-like associated enzyme aldehyde dehydrogenase (ALDH). Loss of RelB significantly inhibited spheroid formation, ALDH expression and activity, chemoresistance, and tumorigenesis in subcutaneous and intrabursal mouse xenograft models of human ovarian cancer. RelB also affected expression of the ALDH gene ALDH1A2 Interestingly, classical NFκB signaling through the RelA transcription factor was equally important for tumorigenesis in the intrabursal model, but had no effect on ALDH. In this case, classical signaling via RelA was essential for proliferating cells, whereas the alternative signaling pathway was not. Our results show how NFκB sustains diverse cancer phenotypes via distinct classical and alternative signaling pathways, with implications for improved understanding of disease recurrence and therapeutic response. Cancer Res; 77(24); 6927-40. ©2017 AACR.

Epigenetic inactivation of follistatin-like 1 mediates tumor immune evasion in nasopharyngeal carcinoma

Follistatin like-1 (FSTL1) is a secreted glycoprotein involved in a series of physiological and pathological processes. However, its contribution to the development of cancer, especially the pathogenesis of nasopharyngeal carcinoma (NPC), remains to be elucidated. We aimed to investigate the dysregulation of FSTL1 and its possible function in NPC. FSTL1 was frequently downregulated in NPC cell lines and primary tumor biopsies by promoter hypermethylation. Ectopic expression of FSTL1 significantly suppressed the colony formation, proliferation, migration and invasion ability of NPC cells and induced cell apoptosis. Overexpression of FSTL1 decreased the tumorigenicity of NPC cells in vivo. In addition, the proliferation of NPC cells in vitro was inhibited by treatment with soluble recombinant FSTL1 protein. The protein level of FSTL1 was decreased in primary NPC tumors and was associated with downregulated interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α). Furthermore, recombinant human FSTL1 protein induced secretion of IL-1β and TNF-α in macrophage cultures, therefore FSTL1 might activate macrophages and attenuate the immune evasion of NPC cells. In conclusion, the epigenetic downregulation of FSTL1 may suppress the proliferation and migration of NPC cells, leading to dysfunctional innate responses in surrounding macrophages.

TFPI2AS1, a novel lncRNA that inhibits cell proliferation and migration in lung cancer

Accumulating evidence demonstrates that a series of differentially expressed lncRNAs is important in tumorigenesis. However, the function of many of the lncRNAs in lung cancer remains elusive. In the present study, we used microarray analysis to identify lncRNAs that are dysregulated in non-small-cell lung cancer (NSCLC) as compared with normal tissues. Among the dysregulated lncRNAs, we identified TFPI2AS1, an antisense transcript of the tumor suppressor TFPI2 (tissue factor pathway inhibitor 2). TFPI2AS1 was shown to be markedly upregulated in NSCLC patient tumors as compared to paired non-tumor samples. TFPI2AS1 knockdown increased NSCLC cell proliferation and migration, which was associated with enhanced G1/S transition and downregulation of cyclin D1 and cyclin-dependent kinases 2 (CDK2), while TFPI2AS1 overexpression had the opposite effect. Knockdown and overexpression experiments also suggested that TFPI2AS1 regulates NSCLC cell migration and AKT activation. Moreover, TFPI2AS1 is a positive regulator of TFPI2. Our findings bring new insights for understanding the role of TFPI2AS1 in mediating the proliferation and migration of NSCLC cells by regulating TFPI2 expression.

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.

The potent tumor suppressor miR-497 inhibits cancer phenotypes in nasopharyngeal carcinoma by targeting ANLN and HSPA4L

Nasopharyngeal carcinoma (NPC) is a malignancy with poor prognosis that is endemic to Southeast Asia. We profiled microRNAs (miRNAs) of NPCs using microarrays and confirmed the results by quantitative RT-PCR. The results revealed that seven miRNAs were significantly up-regulated, and six miRNAs were down-regulated, in NPC tissues relative to noncancerous nasopharyngeal epithelia (NNE). Expression of miR-497 was also significantly reduced in the plasma of NPC patients relative to the plasma of noncancerous control patients. The concordant down-regulation of miR-497 in tissues and plasma suggested that miR-497 could be used as a diagnostic biomarker for NPC. Functional analyses of the effect of miR-497 on cancer phenotypes revealed that transfection of miR-497 mimic into NPC cells suppressed cell growth and migration and induced apoptosis. Subcutaneous xenografts of transfected cells in nude mice demonstrated that miR-497 significantly inhibited tumor growth. Two potential targets of miR-497, ANLN (anillin, actin-binding protein) and HSPA4L (heat shock 70 kDa protein 4–like), both of which were overexpressed in NPC tissues, were negatively regulated by miR-497 mimic in NPC cell lines. Silencing of ANLN and HSPA4L suppressed cell proliferation and migration and induced apoptosis in NPC cells. Our findings indicate that miR-497 is a potent tumor suppressor that inhibits cancer phenotypes by targeting ANLN and HSPA4L in NPC.

Epigenome-wide analysis of DNA methylation reveals a rectal cancer-specific epigenomic signature

Aim: The aim of the present study is to address a genome-wide search for novel methylation biomarkers in the rectal cancer (RC), as only scarce information on methylation profile is available. Materials & methods: We analyzed methylation status in 25 pairs of RC and adjacent healthy mucosa using the Illumina Human Methylation 450 BeadChip. Results: We found significantly aberrant methylation in 33 genes. After validation of our results by pyrosequencing, we found a good agreement with our findings. The BPIL3 and HBBP1 genes resulted hypomethylated in RC, whereas TIFPI2, ADHFE1, FLI1 and TLX1 were hypermethylated. An external validation by TCGA datasets confirmed the results. Conclusion: Our study, with external validation, has demonstrated the feasibility of using specific methylated DNA signatures for developing biomarkers in RC.

Inflammation-Related DNA Damage and Cancer Stem Cell Markers in Nasopharyngeal Carcinoma

Nitrative and oxidative DNA damage plays an important role in inflammation-related carcinogenesis. To investigate the involvement of stem cells in Epstein-Barr virus infection-related nasopharyngeal carcinoma (NPC), we used double immunofluorescence staining to examine several cancer stem/progenitor cell markers (CD44v6, CD24, and ALDH1A1) in NPC tissues and NPC cell lines. We also measured 8-nitroguanine formation as an indicator of inflammation-related DNA lesions. The staining intensity of 8-nitroguanine was significantly higher in cancer cells and inflammatory cells in the stroma of NPC tissues than in chronic nasopharyngitis tissues. Expression levels of CD44v6 and ALDH1A1 were significantly increased in cancer cells of primary NPC specimens in comparison to chronic nasopharyngitis tissues. Similarly, more intense staining of CD44v6 and ALDH1A1 was detected in an NPC cell line than in an immortalized nasopharyngeal epithelial cell line. In the case of CD24 staining, there was no significant difference between NPC and chronic nasopharyngitis tissues. 8-Nitroguanine was detected in both CD44v6- and ALDH1A1-positive stem cells in NPC tissues. In conclusion, CD44v6 and ALDH1A1 are candidate stem cell markers for NPC, and the increased formation of DNA lesions by inflammation may result in the mutation of stem cells, leading to tumor development in NPC.

Trypsinogen 4 boosts tumor endothelial cells migration through proteolysis of tissue factor pathway inhibitor-2

Proteases contribute to cancer in many ways, including tumor vascularization and metastasis, and their pharmacological inhibition is a potential anticancer strategy. We report that human endothelial cells (EC) express the trypsinogen 4 isoform of the serine protease 3 (PRSS3), and lack both PRSS2 and PRSS1. Trypsinogen 4 expression was upregulated by the combined action of VEGF-A, FGF-2 and EGF, angiogenic factors representative of the tumor microenvironment. Suppression of trypsinogen 4 expression by siRNA inhibited the angiogenic milieu-induced migration of EC from cancer specimens (tumor-EC), but did not affect EC from normal tissues. We identified tissue factor pathway inhibitor-2 (TFPI-2), a matrix associated inhibitor of cell motility, as the functional target of trypsinogen 4, which cleaved TFPI-2 and removed it from the matrix put down by tumor-EC. Silencing tumor-EC for trypsinogen 4 accumulated TFPI2 in the matrix. Showing that angiogenic factors stimulate trypsinogen 4 expression, which hydrolyses TFPI-2 favoring a pro-migratory situation, our study suggests a new pathway linking tumor microenvironment signals to endothelial cell migration, which is essential for angiogenesis and blood vessel remodeling. Abolishing trypsinogen 4 functions might be an exploitable strategy as anticancer, particularly anti-vascular, therapy.

Low expression of Aldo-keto reductase 1B10 is a novel independent prognostic indicator for nasopharyngeal carcinoma

Background

Nasopharyngeal carcinoma (NPC) is one of the most common human head and neck cancers with high incidence in Southern China, Southeast Asia and North Africa. Because of its nonspecific symptoms, the early diagnosis of NPC is very difficult. The 5-year survival rate is not ideal in spite of great innovations in radiation and chemotherapy treatments. Highly sensitive and specific prognostic biomarkers are eager for NPC clinical diagnosis. To find specific target molecules is very important for individualized treatment. Aldo–keto reductase B10 (AKR1B10) is closely related to tumorigenesis and tumor development, and however, its expression level in NPC tissues is not clear.

Results

AKR1B10 expression levels were validated in benign, para-cancerous nasopharyngeal and NPC tissues by immunohistochemical evaluation. AKR1B10 was positively expressed in 42 (82.4 %) of 51 benign specimens, and 235 (98.7 %) of 238 para-carcinoma specimens. This percentage was significantly higher than 44.5 % (133/299) in nasopharyngeal carcinoma tissue (p < 0.01). AKR1B10 mRNA quantitative levels detected by real-time quantitative RT-PCR in 90 NPC tissue samples (0.10 ± 0.21) were significantly lower than that in 15 benign tissue samples (1.03 ± 1.12) (p < 0.01). AKR1B10 expression levels in NPC were correlated negatively with T-classification, lymph node metastasis (p < 0.05). We established nasopharyngeal cancer monoclonal cells CNE-2/AKR1B10 with AKR1B10 stable expression and CNE-2/vector cells without AKR1B10 expression by using a modified lentivirus-mediated method, and found that AKR1B10 inhibited the proliferation of CNE-2/AKR1B10 cells by using MTT assay and flow cytometry, and cell migration by in vitro scratch test.

Conclusion

Taken together, our data suggest that low expression of AKR1B10 is an independent prognostic indicator in nasopharyngeal carcinoma, and that AKR1B10 may be involved in regulating the proliferation and migration of nasopharyngeal cancer cells.

Methylation of tissue factor pathway inhibitor 2 as a prognostic biomarker for hepatocellular carcinoma after hepatectomy

BACKGROUND AND AIM

Methylation of tissue factor pathway inhibitor 2 (TFPI2) gene has been detected in hepatocellular carcinoma (HCC). However, the clinicopathologcial significance and prognostic value of TFPI2 methylation in HCC remains largely unknown. This study aimed to investigate the prognostic value of TFPI2 methylation in HCC after hepatectomy.

METHODS

Methylation status of TFPI2 gene was examined in 178 surgical specimens of HCC and 20 normal liver samples using methylation-specific polymerase chain reaction.

RESULTS

Methylation of TFPI2 gene was detected in 44.9% (80 of 178) of primary HCC samples, 10.7% (19 of 178) of the corresponding non-tumorous liver samples, and 5.0% (1/20) of the normal liver samples. The mRNA concentrations of TFPI2 in primary HCC tissues were significantly lower than those in corresponding non-tumorous liver tissues and those in normal liver tissues. TFPI2 methylation was significantly associated with higher TNM stage. Patients with TFPI2 methylation demonstrated a significantly poorer prognosis than those without TFPI2 methylation for both overall survival and disease-free survival (P < 0.001, respectively). Multivariate analyses confirmed that TFPI2 methylation was an independent prognostic factor for both overall survival (P = 0.002) and disease-free survival (P = 0.000) in HCC after hepatectomy. Moreover, TFPI2 methylation was found to be the only independent predictor for early tumor recurrence of HCC after resection based on multivariate analysis (P = 0.002).

CONCLUSIONS

Methylation of TFPI2 predicts high risk of advanced tumor stage, early tumor recurrence, and poor prognosis, and it could be a potential prognostic biomarker in patients with HCC after hepatectomy.

Expression array analysis of the hepatocyte growth factor invasive program

Signaling by human hepatocyte growth factor (hHGF) via its cell surface receptor (MET) drives mitogenesis, motogenesis and morphogenesis in a wide spectrum of target cell types and embryologic, developmental and homeostatic contexts. Oncogenic pathway activation also contributes to tumorigenesis and cancer progression, including tumor angiogenesis and metastasis, in several prevalent malignancies. The HGF gene encodes full-length hHGF and two truncated isoforms known as NK1 and NK2. NK1 induces all three HGF activities at modestly reduced potency, whereas NK2 stimulates only motogenesis and enhances HGF-driven tumor metastasis in transgenic mice. Prior studies have shown that mouse HGF (mHGF) also binds with high affinity to human MET. Here we show that, like NK2, mHGF stimulates cell motility, invasion and spontaneous metastasis of PC3M human prostate adenocarcinoma cells in mice through human MET. To identify target genes and signaling pathways associated with motogenic and metastatic HGF signaling, i.e., the HGF invasive program, gene expression profiling was performed using PC3M cells treated with hHGF, NK2 or mHGF. Results obtained using Ingenuity Pathway Analysis software showed significant overlap with networks and pathways involved in cell movement and metastasis. Interrogating The Cancer Genome Atlas project also identified a subset of 23 gene expression changes in PC3M with a strong tendency for co-occurrence in prostate cancer patients that were associated with significantly decreased disease-free survival.

Decreased expression of TFPI-2 correlated with increased expression of CD133 in cholangiocarcinoma

BACKGROUND

Recent findings suggest decreasing TFPI-2 expression plays a significant role in inhibiting cell migration and tumor invasion. The clinicopathological significance of the expression of TFPI-2 and its possible correlation with the expression of CD133 in cholangiocarcinoma remains to be solved.

METHODS

We investigated if TFPI-2 was involved in the clinicopathological significance of cholangiocarcinoma. An immunohistochemical method was used to detect 218 cases of cholangiocarcinoma, 30 para-neoplastic and 20 normal bile ducts for their expression status of TFPI-2 and CD133, and then the results were analyzed with the patient's age, sex, tumor site and the histological grade, clinical stage as well as overall mean survival time.

RESULTS

Compared with the para-neoplastic and normal cholangiocytes, the expression of TFPI-2 was obviously decreased while the expression of CD133 in carcinoma cells was increased. Carcinomas with low expression of TFPI-2 were significantly corresponding to the tumor site (P = 0.006), size (P = 0.005), histological grade (P = 0.0001) and clinical stage (P = 0.0001), but not to the age (P = 0.066) and sex (P = 0.411), respectively. By Kaplan-Meier survival analysis, the low expression of TFPI-2 was significantly correlative with the overall survival time (P = 0.0001). Further, the expression of TFPI-2 was found inversely correlative with the expression of CD133 (g = -0.3876, P < 0.0001).

CONCLUSIONS

Our finding suggests that the decreased expression of TFPI-2 may play an important role in the carcinogenesis and progression, and may become a new adjunct marker in the diagnosis and prognosis in cholangiocarcinoma. The expression of TFPI-2 may be inversely correlative with the expression of CD133.

Oxidative stress and its significant roles in neurodegenerative diseases and cancer

Reactive oxygen and nitrogen species have been implicated in diverse pathophysiological conditions, including inflammation, neurodegenerative diseases and cancer. Accumulating evidence indicates that oxidative damage to biomolecules including lipids, proteins and DNA, contributes to these diseases. Previous studies suggest roles of lipid peroxidation and oxysterols in the development of neurodegenerative diseases and inflammation-related cancer. Our recent studies identifying and characterizing carbonylated proteins reveal oxidative damage to heat shock proteins in neurodegenerative disease models and inflammation-related cancer, suggesting dysfunction in their antioxidative properties. In neurodegenerative diseases, DNA damage may not only play a role in the induction of apoptosis, but also may inhibit cellular division via telomere shortening. Immunohistochemical analyses showed co-localization of oxidative/nitrative DNA lesions and stemness markers in the cells of inflammation-related cancers. Here, we review oxidative stress and its significant roles in neurodegenerative diseases and cancer.

Epigenetic silencing of TFPI-2 in canine diffuse large B-cell lymphoma

Epigenetic modifications are important early events during carcinogenesis. In particular, hypermethylation of CpG islands in the promoter region of tumor suppressor genes is a well-known mechanism of gene silencing that contributes to cancer development and progression. Tissue factor pathway inhibitor 2 (TFPI-2) is a tumor suppressor involved in invasiveness inhibition. Although TFPI-2 transcriptional silencing, through promoter hypermethylation, has been widely reported in several human malignancies, it has never been explored in lymphoma. In the present study TFPI-2 methylation and gene expression have been investigated in canine Diffuse Large B-cell lymphomas (cDLBCL). The methylation level of 23 CpGs located within the TFPI-2 promoter was investigated by bisulfite-specific PCR and next generation amplicon deep sequencing (GS Junior 454, Roche) in 22 cDLBCLs and 9 controls. For the same specimens, TFPI-2 gene expression was assessed by means of Real-time RT-PCR. Sequence analysis clearly demonstrated that TFPI2 is frequently hypermethylated in cDLBCL. Hypermethylation of the TFPI-2 promoter was found in 77% of DLBCLs (17 out of 22) and in one normal lymph node. Globally, dogs with DLBCL showed a mean methylation level significantly increased compared to controls (p<0.01) and analysis of hypermethylation by site identified 19 loci out of 23 (82%) with mean methylation levels from 2- to 120-fold higher in cDLBCL. Gene expression analysis confirmed a significant down-regulation of TFPI-2 (p<0.05) in DLBCLs compared with normal lymph nodes, suggesting that TFPI-2 hypermethylation negatively regulates its transcription. In addition, a significant positive correlation (p<0.01) was found between TFPI-2 methylation levels and age providing the first indication of age-associated epigenetic modifications in canine DLBCL. To conclude, our findings demonstrated that epigenetic dysregulation of TFPI-2, leading to its reduced expression, is frequently detected in canine DLBCL. In the next future, the aberrant TFPI-2 promoter hypermethylation may be considered in association with prognosis and therapy.

Identification of hypermethylation in hepatocyte cell adhesion molecule gene promoter region in bladder carcinoma

BACKGROUND

Epigenetic regulation such as aberrant hypermethylation of CpG islands in promoter plays a key role in tumorigenesis. 5-Aza-2'-deoxycytidine (5-aza-CdR) which is a potent inhibitor of DNA methylation can reverse the abnormal hypermethylation of the silenced tumor suppressor genes (TSGs). It has been reported that hepatocyte cell adhesion molecule (hepaCAM) acts as a tumor suppressor gene and expression of its mRNA and protein were down-regulated in bladder cancer. Over-expression of hepaCAM can inhibit cancer growth and arrest renal cancer cells at G0/G1 phase. In this study, we investigated the methylation status of hepaCAM gene, as well as the influence of 5-aza-CdR on expression of hepaCAM gene in bladder cancer cells.

METHODS

CpG islands in hepaCAM promoter and methprimers were predicted and designed using bioinformatics program. Methylation status of hepaCAM promoter was evaluated in bladder cancer tissues and two cell lines (T24 and BIU-87) by Methylation-specific PCR; Western blot and Immunofluorescence were used to detect expression of hepaCAM protein after 5-aza-CdR treatment; Flow cytometry assay was performed to determine effectiveness of 5-aza-CdR on cell cycle profile.

RESULTS

CpG island in promoter of hepaCAM gene was hyper-methylated both in bladder carcinoma tissues and cell lines (T24 and BIU-87). Otherwise, aberrant methylation of its promoter was associated with its decreased expression. Hypermethylation of hepaCAM gene was reversed and expression of its mRNA and protein were re-activated in two cell lines by DNA methyltransferases inhibitor 5-aza-CdR. Flow cytometry assay demonstrated that 5-aza-CdR can inhibit growth of cancer cells by arresting cancer cells at G0/G1 phase.

CONCLUSION

Abnormal hypermethylation in CpG island of hepaCAM promoter is involved in absence of hepaCAM gene expression when bladder cancer occurs. Re-activation of hepaCAM gene by 5-aza-CdR can inhibit growth of cancer cells and arrest cells at G0/G1 phase.

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.

Methylation of TFPI-2 is an early event of esophageal carcinogenesis

AIMS

To explore the epigenetic changes and the function of TFPI-2 in esophageal cancer.

MATERIALS & METHODS

Nine esophageal cancer cell lines, nine normal esophageal mucosa, 60 esophageal dysplasia and 106 advanced esophageal cancer samples were included in this study. TFPI-2 methylation was examined by methylation-specific PCR. TFPI-2 expression was evaluated by immunohistochemistry in tissue samples. The effect of TFPI-2 on proliferation, apoptosis, invasion and migration was analyzed by colony formation assay, western blot assay, transwell assay and flow cytometric analysis.

RESULTS

TFPI-2 expression was regulated by promoter region hypermethylation in human esophageal cancer cell lines, and TFPI-2 expression is inversely correlated with methylation in primary cancer. Methylation was found in 28.2, 33.3 and 33.3% of grade 1, 2 and 3 esophageal dysplasia, and 67% of primary esophageal cancer, but no methylation was found in normal mucosa. Methylation is significantly related to tumor differentiation. Inhibition of invasion, migration, colony formation and proliferation, and induction of apoptosis occurred with the restoration of TFPI-2 expression in the KYSE70 cell line.

CONCLUSION

TFPI-2 is frequently methylated in esophageal cancer with a progression tendency. TFPI-2 is a potential tumor suppressor in esophageal cancer.

Periostin, a stroma-associated protein, correlates with tumor invasiveness and progression in nasopharyngeal carcinoma

Recently, the tumor microenvironment is increasingly recognized as playing an important role in cancer proliferation, invasion, and metastasis. To screen stroma-associated proteins involved in nasopharyngeal carcinoma (NPC) carcinogenesis, laser capture microdissection (LCM) and quantitative proteomic analysis were employed to assess different protein expression of the stroma between NPC and normal nasopharyngeal mucosa (NNM). In this study, periostin was identified to be significantly up-regulated in NPC stroma compared with NNM stroma and the result was further confirmed by Western blotting. Immunohistochemistry showed that over-expression of periostin was frequently observed in the stroma of NPC and matched lymph node metastases (LNM) compared with the stroma of NNM. Statistical analysis showed over-expression of periostin was significantly associated with advanced clinical stage (P < 0.001) and lymph node metastasis (P < 0.001) and decreased overall survival (P < 0.001) in NPC. Cox regression analysis indicated over-expression of periostin was an independent prognostic factor. Furthermore, ectopic expression of periostin was used to examine its effect on invasiveness of NPC cell in vitro and the result showed that periostin was able to promote invasiveness of NPC cell. In conclusion, periostin expression is correlated with tumor stage, lymph node metastasis, and patient survival. Periostin is a potential biomarker for the differentiation and prognosis of NPC, and it might play an important role in the progression of NPC.

Adenovirus-mediated gene transfer of tissue factor pathway inhibitor-2 inhibits gallbladder carcinoma growth in vitro and in vivo

Tissue factor pathway inhibitor-2 (TFPI-2) has been identified as a tumor suppressor gene in several types of cancers, but its role in gallbladder carcinoma (GBC) is yet to be determined. In the present study, TFPI-2 expression in GBC tissues was examined, and its inhibitory activities against GBC growth were evaluated in vitro and in vivo after adenovirus-mediated gene transfer of TFPI-2 (Ad5-TFPI-2) was constructed to restore the expression of TFPI-2 in GBC cell lines (GBC-SD, SGC-996, NOZ) and xenograft tumors. Immunohistochemical staining showed that TFPI-2 was significantly downregulated in GBC tissue specimens. Ad5-TFPI-2 could significantly inhibit GBC growth both in vitro and in vivo. Apoptosis analysis and western blotting assay demonstrated that Ad5-TFPI-2 could induce the apoptosis of both GBC cell lines and tissues by promoting the activities of cytochrome c, Bax, caspase-3 and -9 and suppressing Bcl-2 activity. These data indicated that TFPI-2 acts as a tumor suppressor in GBC, and may have a potential role in gene therapy for GBC.

Defining the molecular signature of chemotherapy-mediated lung tumor phenotype modulation and increased susceptibility to T-cell killing

Chemotherapy with platinum doublets, including cisplatin plus vinorelbine, is standard of care for non-small-cell lung cancer. Sublethal exposure to certain chemotherapeutic agents has been demonstrated to alter the phenotype or biology of human tumor cells, rendering them more susceptible to cytotoxic T lymphocyte (CTL)-mediated lysis. The effects of cisplatin/vinorelbine on tumor sensitivity to T-cell cytotoxicity and its molecular mechanisms, however, have not been fully elucidated. We examined the effect of this chemotherapy on growth, cell-surface phenotype, and CTL-mediated lysis of five distinct human lung carcinoma cell lines in vitro and examined the molecular mechanisms associated with enhanced CTL sensitivity. These studies demonstrate that sublethal exposure of human lung tumor cells to the platinum doublet modulates tumor cell phenotype and increases sensitivity to major histocompatibility complex-restricted perforin/granzyme-mediated CTL killing. These studies also demonstrate that exposure to chemotherapy markedly decreased the protein secretion ratio of transforming growth factor-β/interleukin (IL)-8. We examined the gene expression profile of two lung tumor cell lines to identify a shared gene signature in response to sublethal cisplatin/vinorelbine and found coordinate expression of only 16 transcripts, including those for cytokine/chemokine expression and apoptosis such as tumor necrosis factor-α, IL8, CXCL5, and B cell lymphoma-2-like genes (BCL-2). Overall, these results suggest that sublethal exposure to cisplatin/vinorelbine increases sensitivity to perforin/granzyme-mediated CTL killing by modulation of (a) tumor phenotype, (b) cytokine/chemokine milieu, and (c) the proapoptotic/antiapoptotic gene ratio. The data presented here propose a complex mechanism that is distinct from and complementary to that of immunogenic cell death. This molecular signature may be useful in predicting responses to immunotherapy as well as provide the rationale for the potential clinical benefit of the combined use of vaccine with cisplatin/vinorelbine regimens.

Role of nitrative and oxidative DNA damage in inflammation-related carcinogenesis

Chronic inflammation induced by biological, chemical, and physical factors has been found to be associated with the increased risk of cancer in various organs. We revealed that infectious agents including liver fluke, Helicobacter pylori, and human papilloma virus and noninfectious agents such as asbestos fiber induced iNOS-dependent formation of 8-nitroguanine and 8-oxo-7, 8-dihydro-2′-deoxyguanosine (8-oxodG) in cancer tissues and precancerous regions. Our results with the colocalization of phosphorylated ATM and γ-H2AX with 8-oxodG and 8-nitroguanine in inflammation-related cancer tissues suggest that DNA base damage leads to double-stranded breaks. It is interesting from the aspect of genetic instability. We also demonstrated IL-6-modulated iNOS expression via STAT3 and EGFR in Epstein-Barr-virus-associated nasopharyngeal carcinoma and found promoter hypermethylation in several tumor suppressor genes. Such epigenetic alteration may occur by controlling the DNA methylation through IL-6-mediated JAK/STAT3 pathways. Collectively, 8-nitroguanine would be a useful biomarker for predicting the risk of inflammation-related cancers.

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.

TFPI-2 methylation predicts poor prognosis in non-small cell lung cancer

BACKGROUND

Methylation of human tissue factor pathway inhibitor-2 (TFPI-2) gene has been detected in several types of cancer, including non-small cell lung cancer (NSCLC). However, an association between the methylation status of TFPI-2 gene and prognosis has not yet been investigated.

METHODS

Methylation of TFPI-2 gene was examined in a consecutive series of 133 non-metastatic NSCLC patients using methylation-specific PCR (MSP). Univariate and multivariate analyses were conducted to investigate the association between clinical variables and overall survival time.

RESULTS

Methylation of TFPI-2 gene was detected in 36 of 133 patients (27.1%). Of these 36 patients, seventeen individuals (47.2%) carried stage III tumors. The 5-year disease free survival rate among patients carrying methylated TFPI-2 tumors was significantly lower as compared to those with unmethylated TFPI-2 tumors (35.5% versus 6.1%, P<0.0001). Moreover, methylation of TFPI-2 gene was found to be an independent prognostic factor for poor overall survival based on multivariate analysis models (P=0.013), as was age >62 years old (P<0.0001) and TNM stage of disease (P<0.0001).

CONCLUSIONS

The results of the present study suggest that methylation of TFPI-2 gene is an independent factor for an unfavorable prognosis in patients with NSCLC.

Characterization of DOK1, a candidate tumor suppressor gene, in epithelial ovarian cancer

In attempt to discover novel aberrantly hypermethylated genes with putative tumor suppressor function in epithelial ovarian cancer (EOC), we applied expression profiling following pharmacologic inhibition of DNA methylation in EOC cell lines. Among the genes identified, one of particular interest was DOK1, or downstream of tyrosine kinase 1, previously recognized as a candidate tumor suppressor gene (TSG) for leukemia and other human malignancies. Using bisulfite sequencing, we determined that a 5'-non-coding DNA region (located at nt -1158 to -850, upstream of the DOK1 translation start codon) was extensively hypermethylated in primary serous EOC tumors compared with normal ovarian specimens; however, this hypermethylation was not associated with DOK1 suppression. On the contrary, DOK1 was found to be strongly overexpressed in serous EOC tumors as compared to normal tissue and importantly, DOK1 overexpression significantly correlated with improved progression-free survival (PFS) values of serous EOC patients. Ectopic modulation of DOK1 expression in EOC cells and consecutive functional analyses pointed toward association of DOK1 expression with increased EOC cell migration and proliferation, and better sensitivity to cisplatin treatment. Gene expression profiling and consecutive network and pathway analyses were also confirmative for DOK1 association with EOC cell migration and proliferation. These analyses were also indicative for DOK1 protective role in EOC tumorigenesis, linked to DOK1-mediated induction of some tumor suppressor factors and its suppression of pro-metastasis genes. Taken together, our findings are suggestive for a possible tumor suppressor role of DOK1 in EOC; however its implication in enhanced EOC cell migration and proliferation restrain us to conclude that DOK1 represents a true TSG in EOC. Further studies are needed to more completely elucidate the functional implications of DOK1 and other members of the DOK gene family in ovarian tumorigenesis.

Epigenetic disruption of cell signaling in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignancy with remarkable ethnic and geographic distribution in southern China and Southeast Asia. Alternative to genetic changes, aberrant epigenetic events disrupt multiple genes involved in cell signaling pathways through DNA methylation of promoter CpG islands and/or histone modifications. These epigenetic alterations grant cell growth advantage and contribute to the initiation and progression of NPC. In this review, we summarize the epigenetic deregulation of cell signaling in NPC tumorigenesis and highlight the importance of identifying epigenetic cell signaling regulators in NPC research. Developing pharmacologic strategies to reverse the epigenetic-silencing of cell signaling regulators might thus be useful to NPC prevention and therapy.