Cyclophilin A promotes human hepatocellular carcinoma cell metastasis via regulation of MMP3 and MMP9

PPIA enhances cell growth and metastasis through CD147 in oral cancer

Oral cancer is a malignant tumor, and the associated death rate has significantly increased over the past few decades. Secreted fractions are involved in various physiological processes, and their analysis has become a promising approach for discovering diagnostic and prognostic biomarkers for cancer detection and monitoring metastasis. Therefore, the discovery of potential prognostic, diagnostic, and therapeutic biomarkers for oral cancer metastasis is beneficial for developing effective strategies in oral cancer therapy. In this study, we used secretomic analysis to identify the secreted proteins involved in oral cancer. One of the identified proteins, peptidylprolyl isomerase A (PPIA), was selected for further investigation. We used RNA interference to investigate the effect of PPIA secretion on invasion and migration of OC3-I5 cells. Our results showed that reducing the expression and secretion of PPIA significantly decreased invasion and migration of OC3-I5 cells. Next, we used recombinant PPIA to investigate its direct effect on OC3 cell metastasis. The results revealed that proliferation, migration, and invasion of OC3 cells were significantly increased by treatment with the recombinant PPIA. Immunohistochemical analyses revealed higher PPIA expression in tumor tissues compared to normal tissues. Concisely, PPIA activated the ERK1/2 and p38 MAPK signaling pathways and enhanced cell proliferation and metastasis through CD147. In summary, PPIA may prove to be a novel target for oral cancer therapy as well as a prognostic marker.

Cyclophilin A: promising target in cancer therapy

Cyclophilin A (CypA), a member of the immunophilin family, stands out as the most prevalent among the cyclophilins found in humans. Beyond serving as the intracellular receptor for the immunosuppressive drug cyclosporine A (CsA), CypA exerts critical functions within the cell via its peptidyl-prolyl cis-trans isomerase (PPIase) activity, which is crucial for processes, such as protein folding, trafficking, assembly, modulation of immune responses, and cell signaling. Increasing evidence indicates that CypA is up-regulated in a variety of human cancers and it may be a novel potential therapeutic target for cancer treatment. Therefore, gaining a thorough understanding of CypA's contribution to cancer could yield fresh perspectives and inform the development of innovative therapeutic approaches. This review delves into the multifaceted roles of CypA in cancer biology and explores the therapeutic potential of targeting CypA.

NQO1 Triggers Neutrophil Recruitment and NET Formation to Drive Lung Metastasis of Invasive Breast Cancer

Metastasis to the lungs is a leading cause of death for patients with breast cancer. Therefore, effective therapies are urgently needed to prevent and treat lung metastasis. In this study, we uncovered a mechanism by which NAD(P)H:quinone oxidoreductase 1 (NQO1) orchestrates lung metastasis. NQO1 stabilized and upregulated peptidyl-prolyl cis-trans isomerase A (PPIA), a chaperone that regulates protein conformation and activity, by preventing its oxidation at a critical cysteine residue C161. PPIA subsequently activated CD147, a membrane protein that facilitates cell invasion. Moreover, NQO1-induced secretion of PPIA modulated the immune landscape of both primary and lung metastatic sites. Secreted PPIA engaged CD147 on neutrophils and triggered the release of neutrophil extracellular traps (NET) and neutrophil elastase, which enhanced tumor progression, invasiveness, and lung colonization. Pharmacological targeting of PPIA effectively inhibited NQO1-mediated breast cancer lung metastasis. These findings reveal a previously unrecognized NQO1-PPIA-CD147-NET axis that drives breast cancer lung metastasis. Inhibiting this axis is a potential therapeutic strategy to limit lung metastasis in patients with breast cancer.  Significance: NQO1 stabilizes and promotes the secretion of PPIA to activate CD147 in neutrophils and stimulate NET formation, promoting breast cancer lung metastasis and providing therapeutic targets for this fatal condition.

AGR2: The Covert Driver and New Dawn of Hepatobiliary and Pancreatic Cancer Treatment

The anterior gradient protein 2 (AGR2) plays a crucial role in facilitating the formation of protein disulfide bonds within the endoplasmic reticulum (ER). Research suggests that AGR2 can function as an oncogene, with its heightened expression linked to the advancement of hepatobiliary and pancreatic cancers through invasion and metastasis. Notably, AGR2 not only serves as a pro-oncogenic agent but also as a downstream targeting protein, indirectly fostering cancer progression. This comprehensive review delves into the established functions and expression patterns of AGR2, emphasizing its pivotal role in cancer progression, particularly in hepatobiliary and pancreatic malignancies. Furthermore, AGR2 emerges as a potential cancer prognostic marker and a promising target for immunotherapy, offering novel avenues for the treatment of hepatobiliary and pancreatic cancers and enhancing patient outcomes.

Inhibitors of Cyclophilin A: Current and Anticipated Pharmaceutical Agents for Inflammatory Diseases and Cancers

Cyclophilin A, a widely prevalent cellular protein, exhibits peptidyl-prolyl cis-trans isomerase activity. This protein is predominantly located in the cytosol; additionally, it can be secreted by the cells in response to inflammatory stimuli. Cyclophilin A has been identified to be a key player in many of the biological events and is therefore involved in several diseases, including vascular and inflammatory diseases, immune disorders, aging, and cancers. It represents an attractive target for therapeutic intervention with small molecule inhibitors such as cyclosporin A. Recently, a number of novel inhibitors of cyclophilin A have emerged. However, it remains elusive whether and how many cyclophilin A inhibitors function in the inflammatory diseases and cancers. In this review, we discuss current available data about cyclophilin A inhibitors, including cyclosporin A and its derivatives, quinoxaline derivatives, and peptide analogues, and outline the most recent advances in clinical trials of these agents. Inhibitors of cyclophilin A are poised to enhance our comprehension of the molecular mechanisms that underpin inflammatory diseases and cancers associated with cyclophilin A. This advancement will aid in the development of innovative pharmaceutical treatments in the future.

Secreted cyclophilin A is non-genotoxic but acts as a tumor promoter

Chronic inflammation is associated with malignant transformation and creates the microenvironment for tumor progression. Cyclophilin A (CypA) is one of the major pro-inflammatory mediators that accumulates and persists in the site of inflammation in high doses over time. According to multiomics analyses of transformed cells, CypA is widely recognized as a pro-oncogenic factor. Vast experimental data define the functions of intracellular CypA in carcinogenesis, but findings on the role of its secreted form in tumor formation and progression are scarce. In the studies here, we exploit short-term in vitro and in vivo tests to directly evaluate the mutagenic, recombinogenic, and blastomogenic effects, as well as the promoter activity of recombinant human CypA (rhCypA), an analogue of secreted CypA. Our findings showed that rhCypA had no genotoxicity and, thus, was neither involved in nor influenced the initiation stage of carcinogenesis. At high doses, rhCypA could disrupt gap junctions in rat liver epithelial IAR-2 cells in vitro by decreasing the expression of connexins 26 and 43 in these cells and inhibit A549 cell adhesion. These data suggested that rhCypA could contribute to epithelial-mesenchymal transition in malignant cells. The research presented here elucidated the role of secreted CypA in carcinogenesis, revealing that it is not a tumor initiator but can act as a tumor promoter at high concentrations.

Over-expression of USP15/MMP3 predict poor prognosis and promote growth, migration in non-small cell lung cancer cells

Aberrant ubiquitin modifications caused by an imbalance in the activities of ubiquitinases and de-ubiquitinases are emerging as important mechanisms underlying non-small cell lung cancer (NSCLC) progression. The deubiquitinating enzyme ubiquitin-specific peptidase 15 (USP15) has been identified as an important factor in oncogenesis and a potential therapeutic target. However, the expression profile and function of USP15 in NSCLC remain elusive. In the present study, we investigated the expression pattern and the potential biological functions of USP15 in NSCLC both in cells and animal models. Our data revealed that USP15 was highly expressed in NSCLC tissues and cells compared with normal counterpart. We subsequently knocked down USP15 expression in two NSCLC cell lines, which significantly suppressed cell proliferation. In addition, knocking down USP15 expression reduced NSCLC cell migration and invasion according to the results from Matrigel-Transwell analysis. NSCLC animal model results showed that USP15 knockdown also reduced NSCLC size. Biochemical analysis revealed that USP15 knockdown inhibited matrix metalloproteinase (MMP)3 and MMP9 expression. Furthermore, high levels of USP15 and MMP3 expression were associated with poor prognosis in NSCLC. In conclusion, the results from the present study suggest that the high expression of USP15 promotes NSCLC tumorigenesis. Therefore, it is proposed that USP15 and MMPs may represent novel biomarkers for NSCLC progression and prognosis.

Cyclophilin A represses reactive oxygen species generation and death of hypoxic non-small-cell lung cancer cells by degrading thioredoxin-interacting protein

Cyclophilin A (cypA) is overexpressed in many types of carcinomas, including non-small-cell lung cancer (NSCLC). However, the effect of anoxia, a critical feature of the carcinoma cell microenvironment, on cypA expression in NSCLC is unknown. Here, formaldehyde-fixed and paraffin-embedded samples were collected from 60 subjects with NSCLC. The protein expression levels of cypA and hypoxia-inducible factor-1α (HIF-1α) were evaluated using immunohistochemistry. Kaplan-Meier analysis showed that subjects with high cypA expression had remarkably shorter progression-free survival than those with low cypA expression. Furthermore, cypA expression levels were significantly related to HIF-1α expression levels (Spearman's correlation=0.34, P<0.0001). To further assess the effect of cypA, an anoxic carcinoma cell model was established. CypA expression was remarkably upregulated in H1299 and A549 cell lines under hypoxic conditions. Overexpression of cypA restored hypoxia-impaired cell growth and prevented reactive oxygen species (ROS) production and cell death in hypoxic A549 and H1299 cells. However, these phenotypes were not altered by the inactive R55A mutant of cypA. Mechanistic studies demonstrated that cypA can bind to and degrade the tumor suppressor protein TXNIP in H1299 and A549 cells. Restored TXNIP expression in cypA-overexpressed and hypoxic NSCLC cells led to increased ROS levels and apoptotic cell numbers and decreased cell growth compared with cypA-overexpressed and hypoxic NSCLC cells. These findings indicate that anoxia results in an increase in cypA expression in NSCLC. Additionally, cypA served as an oncogene during hypoxia by interacting with TXNIP.

Microplitis bicoloratus bracovirus regulates cyclophilin A-apoptosis-inducing factor interaction to induce cell apoptosis in the insect immunosuppressive process

Microplitis bicoloratus bracovirus (MbBV) induces apoptosis in hemocytes of the host (Spodoptera litura) via the cyclophilin A (CypA)-mediated signaling pathway. However, the mechanisms underlying CypA-mediated signaling during apoptosis remain largely unknown. Therefore, in this study, we investigated how CypA and apoptosis-inducing factor (AIF) interact during MbBV-mediated apoptosis. Our findings showed that MbBV induces apoptosis through the CypA-AIF axis of insect immune suppression. In MbBV-infected Spli221 cells, both the expression of the cypa gene and the release of AIF from the mitochondria increased the number of apoptotic cells. CypA and AIF underwent concurrent cytoplasm-nuclear translocation. Conversely, blocking of AIF release from mitochondria not only inhibited the CypA-AIF interaction but also inhibited the cytoplasmic-nuclear translocation of AIF and CypA. Importantly, the survival of the apoptotic phenotype was significantly rescued in MbBV-infected Spli221 cells. In addition, we found that the cyclosporine A-mediated inhibition of CypA did not prevent the formation of the CypA and AIF complex; rather, this only suppressed genomic DNA fragmentation. In vitro experiments revealed direct molecular interactions between recombinant CypA and AIF. Taken together, our results demonstrate that the CypA-AIF interaction plays an important role in MbBV-induced innate immune suppression. This study will help to clarify aspects of insect immunological mechanisms and will be relevant to biological pest control.

CircSEC24A (hsa_circ_0003528) interference suppresses epithelial-mesenchymal transition of hepatocellular carcinoma cells via miR-421/MMP3 axis

Accumulating evidence indicates that circular RNAs (circRNAs) function as conclusive modulators in diverse tumors, including in hepatocellular carcinoma (HCC). Nonetheless, knowledge of the latent mechanisms involving circRNAs in HCC development is insufficient. circSEC24A (hsa_circ_0003528) was discovered by microarray analysis of patients with HCC. Binding sites between circSEC24A, miR-421, miR-421 and matrix metalloproteinase 3 (MMP3) were predicted using online bioinformatics tools. Interactions involving miRNA and target genes or circRNAs were verified by luciferase reporter-gene and RNA pull-down assays. Two HCC cell lines (HCCLM3 and Hep3B) and normal THLE-2 liver cells were used for in vitro experiments. miRNA and mRNA expression levels were detected by RT-qPCR, and protein expression was measured by western blotting. Cell proliferation was evaluated using Cell Counting Kit 8 (CCK-8) assays along with colony formation assays. Cell invasion and migration were determined using the Transwell and wound healing migration assays. A xenograft model was used to evaluate the role of circSEC24A in vivo. circSEC24A expression was significantly upregulated in HCCLM3 and Hep3B cells. Silencing circSEC24A mitigated the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of HCC cells, which was abrogated by downregulation of miR-421. Meanwhile, MMP3 could bind to miR-421 to decrease the functional effects of miR-421 and induce tumor metastasis. Knockdown of cicSEC24A suppressed tumor growth in vivo. circSEC24A interference suppressed HCC cell EMT by sponging miR-421, further regulating MMP3, and inhibiting tumor growth in vivo. Therefore, circSEC24A could represent a potential target for HCC patient treatment.

The Role of Cyclophilins in Inflammatory Bowel Disease and Colorectal Cancer

Cyclophilins (Cyps) is a kind of ubiquitous protein family in organisms, which has biological functions such as promoting intracellular protein folding and participating in the pathological processes of inflammation and tumor. Inflammatory bowel disease (IBD) and colorectal cancer (CRC) are two common intestinal diseases, but the etiology and pathogenesis of these two diseases are still unclear. IBD and CRC are closely associated, IBD has always been considered as one of the main risks of CRC. However, the role of Cyps in these two related intestinal diseases is rarely studied and reported. In this review, the expression of CypA, CypB and CypD in IBD, especially ulcerative colitis (UC), and CRC, their relationship with the development of these two intestinal diseases, as well as the possible pathogenesis, were briefly summarized, so as to provide modest reference for clinical researches and treatments in future.

CypA: A Potential Target of Tumor Radiotherapy and/or Chemotherapy

Cyclophilin A (CypA) is a ubiquitous and highly conserved protein. CypA, the intracellular target protein for the immunosuppressant cyclosporine A (CsA), plays important cellular roles through peptidyl-prolyl cis-trans isomerase (PPIase). Increasing evidence shows that CypA is up-regulated in a variety of human cancers. In addition to being involved in the occurrence and development of multiple tumors, overexpression of CypA has also been shown to be strongly associated with malignant transformation. Surgery, chemotherapy and radiotherapy are the three main treatments for cancer. Chemotherapy and radiotherapy are often used as direct or adjuvant treatments for cancer. However, various side effects and resistance to both chemotherapy and radiotherapy bring great challenges to these two forms of treatment. According to recent reports, CypA can improve the chemosensitivity and/or radiosensitivity of cancers, possibly by affecting the expression of drug-resistant related proteins, cell cycle arrest and activation of the mitogen-activated protein kinase (MAPK) signaling pathways. In this review, we focus on the role of CypA in cancer, its impact on cancer chemotherapeutic and radiotherapy sensitivity, and the mechanism of action. It is suggested that CypA may be a novel potential therapeutic target for cancer chemotherapy and/or radiotherapy.

Matrix Metalloproteinases as Potential Biomarkers and Therapeutic Targets in Liver Diseases

Chronic liver diseases, characterized by an excessive accumulation of extracellular matrix (ECM) resulting in scar tissue formation, are a growing health problem causing increasing morbidity and mortality worldwide. Currently, therapeutic options for tissue fibrosis are severely limited, and organ transplantation is the only treatment for the end-stage liver diseases. During liver damage, injured hepatocytes release proinflammatory factors resulting in the recruitment and activation of immune cells that activate quiescent hepatic stellate cells (HSCs). Upon activation, HSCs transdifferentiate into highly proliferative, migratory, contractile and ECM-producing myofibroblasts. The disrupted balance between ECM deposition and degradation leads to the formation of scar tissue referred to as fibrosis. This balance can be restored either by reducing ECM deposition (by inhibition of HSCs activation and proliferation) or enhancing ECM degradation (by increased expression of matrix metalloproteinases (MMPs)). MMPs play an important role in ECM remodeling and represent an interesting target for therapeutic drug discovery. In this review, we present the current knowledge about ECM remodeling and role of the different MMPs in liver diseases. MMP expression patterns in different stages of liver diseases have also been reviewed to determine their role as biomarkers. Finally, we highlight MMPs as promising therapeutic targets for the resolution of liver diseases.

Sex Hormone-Dependent Physiology and Diseases of Liver

Sexual dimorphism is associated not only with somatic and behavioral differences between men and women, but also with physiological differences reflected in organ metabolism. Genes regulated by sex hormones differ in expression in various tissues, which is especially important in the case of liver metabolism, with the liver being a target organ for sex hormones as its cells express estrogen receptors (ERs: ERα, also known as ESR1 or NR3A; ERβ; GPER (G protein-coupled ER, also known as GPR 30)) and the androgen receptor (AR) in both men and women. Differences in sex hormone levels and sex hormone-specific gene expression are mentioned as some of the main variations in causes of the incidence of hepatic diseases; for example, hepatocellular carcinoma (HCC) is more common in men, while women have an increased risk of autoimmune liver disease and show more acute liver failure symptoms in alcoholic liver disease. In non-alcoholic fatty liver disease (NAFLD), the distinction is less pronounced, but increased incidences are suggested among men and postmenopausal women, probably due to an increased tendency towards visceral fat accumulation.

Cyclophilin A and matrix metalloproteinase-9: Their relationship, association with, and diagnostic relevance in stable coronary artery disease

Objectives

Data about the circulating levels of cyclophilin A and matrix metalloproteinase-9 in stable coronary artery disease are contradictory. Moreover, their relationship in this disease is not established yet. Thus, this study was designed to assess the relationship between the circulating levels of cyclophilin A and matrix metalloproteinase-9 in coronary artery disease patients with and without type 2 diabetes mellitus (T2DM).

Methods

Serum levels of cyclophilin A, matrix metalloproteinase-9, and high sensitive C-reactive protein (hsCRP) along with fasting blood glucose, glycated hemoglobin, serum lipids, and the anthropometric parameters were measured in 120 participants who were divided equally into four groups (i) normal controls, (ii) T2DM patients, (iii) stable coronary artery disease patients with T2DM, and (iv) stable coronary artery disease patients without T2DM.

Results

Levels of cyclophilin A and matrix metalloproteinase-9 were significantly elevated in sera of coronary artery disease patients with and without T2DM compared to normal controls and T2DM patients. In multiple linear regression models, only cyclophilin A was observed in the final model where it explained the 24.9% variability of matrix metalloproteinase-9. Additionally, high circulating levels of cyclophilin A and matrix metalloproteinase-9 were associated with an increased risk of developing stable coronary artery disease. Finally, the diagnostic efficacy of cyclophilin A and matrix metalloproteinase-9 to discriminate stable coronary artery disease patients with and without T2DM from subjects without coronary artery disease was found to be higher than that of hsCRP.

Conclusion

Serum level of cyclophilin A might be a determinant factor of matrix metalloproteinase-9 level; both may contribute to the pathogenesis of stable coronary artery disease and they appear to be valuable diagnostic biomarkers of stable coronary artery disease with and without T2DM.

Cyclophilin a knokdown inhibits cell migration and invasion through the suppression of epithelial-mesenchymal transition in colorectal cancer cells

Enhanced expression of cyclophilin A (CypA) in colorectal cancer (CRC) was reported; however, how CypA influences CRC progression is not clear. Therefore, we examine the effects of CypA on CRC cell progression. Knockdown of CypA in SW480 cells significantly inhibited cell migration and invasion but had no effect on cell proliferation. In addition, upregulation of E-cadherin and downregulation of N-cadherin and Snail expression were observed by CypA knockdown. These results suggested that CypA knockdown inhibited cell migration and invasion by suppressing epithelial-mesenchymal transition. CypA knockdown was also associated with increased p38 phosphorylation, and the p38 inhibitor treatment led to increase in the number of invasive CypA-knockdown SW480 cells. Therefore, CypA may be a potential therapeutic target in preventing CRC metastasis.

A Pan-Cyclophilin Inhibitor, CRV431, Decreases Fibrosis and Tumor Development in Chronic Liver Disease Models

Previous studies show that cyclophilins contribute to many pathologic processes, and cyclophilin inhibitors demonstrate therapeutic activities in many experimental models. However, no drug with cyclophilin inhibition as the primary mode of action has advanced completely through clinical development to market. In this study, we present findings on the cyclophilin inhibitor, CRV431, that highlight its potential as a drug candidate for chronic liver diseases. CRV431 was found to potently inhibit all cyclophilin isoforms tested-A, B, D, and G. Inhibitory constant or IC50 values ranged from 1 to 7 nM, which was up to 13 times more potent than the parent compound, cyclosporine A (CsA), from which CRV431 was derived. Other CRV431 advantages over CsA as a nontransplant drug candidate were significantly diminished immunosuppressive activity, less drug transporter inhibition, and reduced cytotoxicity potential. Oral dosing to mice and rats led to good blood exposures and a 5- to 15-fold accumulation of CRV431 in liver compared with blood concentrations across a wide range of CRV431 dosing levels. Most importantly, CRV431 decreased liver fibrosis in a 6-week carbon tetrachloride model and in a mouse model of nonalcoholic steatohepatitis (NASH). Additionally, CRV431 administration during a late, oncogenic stage of the NASH disease model resulted in a 50% reduction in the number and size of liver tumors. These findings are consistent with CRV431 targeting fibrosis and cancer through multiple, cyclophilin-mediated mechanisms and support the development of CRV431 as a safe and effective drug candidate for liver diseases. SIGNIFICANCE STATEMENT: Cyclophilin inhibitors have demonstrated therapeutic activities in many disease models, but no drug candidates have yet advanced completely through development to market. In this study, CRV431 is shown to potently inhibit multiple cyclophilin isoforms, possess several optimized pharmacological properties, and decrease liver fibrosis and tumors in mouse models of chronic liver disease, which highlights its potential to be the first approved drug primarily targeting cyclophilin isomerases.

Cyclophilin Inhibitor NV556 Reduces Fibrosis and Hepatocellular Carcinoma Development in Mice With Non-Alcoholic Steatohepatitis

Hepatocellular carcinoma (HCC), the third major cause of cancer mortality, can result from non-alcoholic steatohepatitis (NASH). Due to limited efficacy of drugs approved for HCC and no drug available yet for NASH, identification of new effective treatments is crucial. Here, we investigated whether NV556, a cyclophilin inhibitor derived from sanglifehrins, would decrease the development of NASH and HCC in a preclinical mouse model. For our experiment, male mice were administered streptozotocin to disrupt pancreatic cells and nourished with high-fat diet since 3 weeks of age. Afterward, NV556 or vehicle was orally administered daily for 6 weeks before the 14-week-old time point for the development of NASH, or 10 weeks before the 30-week-old time point for the establishment of HCC. Body weight, blood glucose level, and liver weight were recorded. Moreover, for NASH, livers were histologically examined for inflammation and steatosis. Collagen was measured by Sirius Red staining of hepatic tissues. Systemic cytokine levels in serum were detected by multiplex assays. For HCC, nodules of livers were measured and scored according to a developed system with number and size of nodules as criteria. NV556 significantly decreased collagen deposition (p = 0.0281), but did not alter inflammation, steatosis, body and liver weight, and systemic cytokine production compared to control mice with NASH symptoms. For HCC, NV556 statistically reduced the number (p = 0.0091) and diameter of tumorous nodules (p = 0.0264), along with liver weight (p = 0.0026) of mice.Our study suggests NV556 as a promising candidate for treatment of NASH-derived fibrosis and HCC.

Targeting the SPOCK1-snail/slug axis-mediated epithelial-to-mesenchymal transition by apigenin contributes to repression of prostate cancer metastasis

Background

Prostate cancer (PCa) is considered one of the most prevalent malignancy globally, and metastasis is a major cause of death. Apigenin (API) is a dietary flavonoid which exerts an antimetastatic effect in various cancer types. Sparc/osteonectin, cwcv, and kazal-like domains proteoglycan 1 (SPOCK1) is a crucial modulator of tumor growth and metastasis in cancers. However, the role and underlying regulatory mechanisms of SPOCK1 in the API-mediated antimetastatic effects of PCa remain unclear.

Methods

MTS, colony formation, wound-healing, and transwell assays were conducted to evaluate the effects of API on PCa cell proliferative, migratory, and invasive potentials. In vivo orthotopic bioluminescent xenograft model were employed to determine antitumor activity of API. PCa cells were transfected with either Snail-, Slug-, SPOCK1-overexpressing vector, or small hairpin (sh)SPOCK1 to determine the invasive abilities and expression levels of SPOCK1 and epithelial-to-mesenchymal transition (EMT) biomarkers in response to API treatment. Immunohistochemical (IHC) assays were carried out to evaluate the expression level of SPOCK1 in PCa xenografts and a PCa tissue array. Associations of SPOCK1 expression with clinicopathological features and prognoses of patients with PCa were analyzed by GEO or TCGA RNA-sequencing data.

Results

API significantly suppressed in vitro PCa cell proliferation, migration, and invasion and inhibited in vivo PCa tumor growth and metastasis. Moreover, survival times of animals were also prolonged after API treatment. Mechanistic studies revealed that API treatment resulted in downregulation of SPOCK1, which was accompanied by reduced expressions of mesenchymal markers and subsequent attenuation of invasive abilities of PCa cells. Overexpression of SPOCK1 in PCa xenografts resulted in significant promotion of tumor progression and relieved the anticancer activities induced by API, whereas knockdown of SPOCK1 had opposite effects. In clinical, SPOCK1 levels were higher in tumor tissues compared to non-tumor tissues, which was also significantly correlated with shorter disease-free survival in PCa patients.

Conclusions

Levels of SPOCK1 increase with the progression of human PCa which suggests that SPOCK1 may act as a prognostic marker or therapeutic target for patients with PCa. Suppression of SPOCK1-mediated EMT signaling contributes to the antiproliferative and antimetastatic activities of API in vitro and in vivo.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1247-3) contains supplementary material, which is available to authorized users.

The oncoprotein HBXIP facilitates metastasis of hepatocellular carcinoma cells by activation of MMP15 expression

Background: Due to the high recurrence and metastasis rate, the clinical outcomes of patients with hepatocellular carcinoma (HCC) are still unsatisfactory. Hepatitis B virus X-interacting protein (HBXIP) has been reported to play crucial roles in carcinogenesis.

Purpose: We aimed to reveal the functional significance and underlying mechanism of HBXIP in HCC metastasis. Methods: Cell transwell assay, in vivo metastasis model, real-time PCR, western blot analysis, luciferase reporter and chromatin immunoprecipitation assays were applied.

Results: Here, we detected the HBXIP expression level and determined its clinical significance in HCC. We found that HBXIP was significantly upregulated in HCC tissues, and correlated with vascular invasion, tumor metastasis and worse prognosis of HCC patients. HBXIP enhanced cell migration and invasion in vitro, and promoted the metastasis of HCC in vivo. Furthermore, we confirmed that HBXIP increased MMP15 expression through association with proto-oncogene c-myc. Depletion of c-myc abolished HBXIP-mediated MMP-15 upregulation. We also observed a positive correlation between HBXIP and MMP15 expression in HCC tissues.

Conclusion: Our results establish a novel function for HBXIP-MMP15 regulation in HCC metastasis and suggest its candidacy as a new prognostic biomarker and therapeutic target for HCC metastasis.

Selected reaction monitoring approach for validating peptide biomarkers

We here describe a selected reaction monitoring (SRM)-based approach for the discovery and validation of peptide biomarkers for cancer. The first stage of this approach is the direct identification of candidate peptides through comparison of proteolytic peptides derived from the plasma of cancer patients or healthy individuals. Several hundred candidate peptides were identified through this method, providing challenges for choosing and validating the small number of peptides that might prove diagnostically useful. To accomplish this validation, we used 2D chromatography coupled with SRM of candidate peptides. We applied this approach, called sequential analysis of fractionated eluates by SRM (SAFE-SRM), to plasma from cancer patients and discovered two peptides encoded by the peptidyl-prolyl cis-trans isomerase A (PPIA) gene whose abundance was increased in the plasma of ovarian cancer patients. At optimal thresholds, elevated levels of at least one of these two peptides was detected in 43 (68.3%) of 63 women with ovarian cancer but in none of 50 healthy controls. In addition to providing a potential biomarker for ovarian cancer, this approach is generally applicable to the discovery of peptides characteristic of various disease states.

Cyclophilin A promotes non-small cell lung cancer metastasis via p38 MAPK

BACKGROUND

Cyclophilin A (CypA) is associated with metastasis in diverse cancers; however, its role in lung cancer metastasis and the underlying mechanisms remain poorly understood. Our study investigated the effect of CypA on non-small cell lung cancer (NSCLC) metastasis in vitro and in vivo to determine its mechanisms.

METHODS

In this study, A549 and H1299 cell lines with downregulated and overexpressed CypA, respectively, were constructed by lentivirus transfection of NSCLC cells. in vitro experiments, including wound healing and transwell assays and Western blotting, showed that CypA promoted cancer cell migration and epithelial-mesenchymal transition in NSCLC. Lung metastasis mouse models were used for the first time to confirm that CypA promoted NSCLC metastasis in vivo. The p38 inhibitor SB203580 was used to show that p38 MAPK is involved in CypA-mediated NSCLC metastasis.

RESULTS

Wound healing and transwell assays showed that the migration of both A549 and H1299 cells decreased in the CypA downregulated group and increased in the CypA overexpressed group. CypA also positively promoted the expression of epithelial-mesenchymal transition-relevant proteins. Results of mouse models confirmed that the tumor metastasis rate was much higher in the CypA overexpressed than in the CypA downregulated group. In addition, SB203580 inhibited NSCLC cell migration significantly in the CypA overexpressed group, while the difference in the CypA downregulated group was not significant.

CONCLUSIONS

In conclusion, this study demonstrated that CypA promotes NSCLC cancer metastasis via p38 MAPK.

Gender disparity in hepatocellular carcinoma (HCC): multiple underlying mechanisms

On the global scale, hepatitis B virus (HBV) infection is the main cause of hepatocellular carcinoma (HCC) especially in regions of Asia where HBV infection is endemic. Epidemiological studies show that the incidence of inflammation-driven HCC in males is three times as high as in females. Recent studies suggest that sex hormones have a crucial role in the pathogenesis and development of HBV-induced HCC. We found that the estrogen/androgen signaling pathway is associated with decreased/increased transcription and replication of HBV genes and can promote the development of HBV infections by up/downregulating HBV RNA transcription and inflammatory cytokines levels, which in turn slow down the progression of HBV-induced HCC. Additionally, sex hormones can also affect HBV-related HCC by inducing epigenetic changes. The evidence that both morphology and function of the human liver are affected by sex hormones was found over 60 years ago. However, the underlying molecular mechanism largely remains to be elucidated. This review focuses mainly on the molecular mechanisms behind the sex difference in HCC associated with HBV and other factors. In addition, several potential treatment and therapeutic strategies for inflammation-driven HCC will be introduced in this review.

Suppression of Ubiquitin-Specific Peptidase 17 (USP17) Inhibits Tumorigenesis and Invasion in Non-Small Cell Lung Cancer Cells

Recently, deubiquitinating enzymes (DUBs) are emerging as new regulators in cancer progression. However, understanding of the involvement of DUBs in non-small cell lung cancer (NSCLC) is just beginning. In this study, we investigated the expression and biological function of ubiquitin-specific peptidase 17 (USP17) in NSCLC progression in vitro and in vivo. We found that the expression of USP17 was higher than in a normal control. We further efficiently depleted USP17 expression in two different NSCLC cells, A549 and H1299. The anchorage-independent growth ability of these cells, estimated by soft agar colony formation assay, was significantly reduced after USP17 knockdown. Moreover, Matrigel–Transwell analysis showed that suppression of USP17 decreased cell migration and invasion capacity. Molecular mechanism studies found that USP17 silencing downregulated the expression of matrix metalloproteases (MMP3 and MMP9) in NSCLC cells. Furthermore, animal model results showed that USP17 suppression inhibited NSCLC tumorigenesis and growth. Altogether, this study illustrates the important functions of USP17 in NSCLC and suggests that USP17 might be an attractive target for NSCLC therapy.

For robust big data analyses: a collection of 150 important pro-metastatic genes

Metastasis is the greatest contributor to cancer-related death. In the era of precision medicine, it is essential to predict and to prevent the spread of cancer cells to significantly improve patient survival. Thanks to the application of a variety of high-throughput technologies, accumulating big data enables researchers and clinicians to identify aggressive tumors as well as patients with a high risk of cancer metastasis. However, there have been few large-scale gene collection studies to enable metastasis-related analyses. In the last several years, emerging efforts have identified pro-metastatic genes in a variety of cancers, providing us the ability to generate a pro-metastatic gene cluster for big data analyses. We carefully selected 285 genes with in vivo evidence of promoting metastasis reported in the literature. These genes have been investigated in different tumor types. We used two datasets downloaded from The Cancer Genome Atlas database, specifically, datasets of clear cell renal cell carcinoma and hepatocellular carcinoma, for validation tests, and excluded any genes for which elevated expression level correlated with longer overall survival in any of the datasets. Ultimately, 150 pro-metastatic genes remained in our analyses. We believe this collection of pro-metastatic genes will be helpful for big data analyses, and eventually will accelerate anti-metastasis research and clinical intervention.

Interaction of cyclophilin A with a novel binding protein, SR-25, and characterization of their expression pattern in Chinese hepatocellular carcinoma patients

Cyclophilin (Cyp) A has been reported to be overexpressed in the majority of cancer cells, including hepatocellular carcinoma (HCC). However, the biological functions of CypA in HCC are far from being understood. To determine the biological functions of CypA in HCC, the present study screened human fetal liver complementary DNA for proteins interacting with CypA using the yeast two-hybrid system. A nuclear protein, serine/arginine-rich (SR)-25, was isolated as a novel CypA-binding protein that is distinct from those previously described in the literature. Binding assays and co-immunoprecipitation confirmed the physical association between CypA and SR-25. The present study demonstrated that CypA may interact with SR-25 through its peptidyl-prolyl isomerase domain. In addition, CypA may induce the expression of SR-25 in Hep3B cells. The messenger RNA levels of CypA and SR-25 in HCC indicated that there was a significant correlation between the expression of CypA and the expression of SR-25 in HCC. It can be speculated that the interaction between CypA and SR-25 proteins may be involved in potential carcinogenic functions of CypA in HCC. Further studies will focus on elucidating in detail the molecular mechanisms of the interaction between CypA and SR-25.

Downregulation of Peptidylprolyl isomerase A promotes cell death and enhances doxorubicin-induced apoptosis in hepatocellular carcinoma

Peptidylprolyl isomerase A (PPIA) is a peptidyl-prolyl cis-trans isomerase that is known to play a critical role in the development of many human cancers. However, the precise biological function of PPIA in hepatocellular carcinoma (HCC) remains largely unclear. In this study, lentiviral overexpression vectors and small interfering RNA knockdown methods were employed to investigate the biological effects of PPIA in HCC. PPIA levels in HCC tissues and peritumoral tissues were detected by real-time Polymerase Chain Reaction (RT-PCR), Western blotting, and immunohistochemistry. Our results indicate that PPIA levels were significantly higher in the HCC tissues compared to the matched peritumoral tissues. Moreover, PPIA expression was significantly associated with tumor size in these tissues. Interestingly, serum PPIA (sPPIA) levels were significantly higher in healthy controls compared to the HCC patients. Knockdown or overexpression of PPIA was shown to downregulate and upregulate cell growth, respectively. Moreover, PPIA siRNA knockdown appears to promote doxorubicin-induced apoptosis in HCC cells, altering the expression of downstream apoptotic factors. In summary, our results indicate that PPIA may play a pivotal role in HCC by regulating cell growth and could serve as a novel marker and therapeutic molecular target for HCC patients.

Matrix metalloproteinase expression and molecular interaction network analysis in gastric cancer

Gastric cancer (GC) is one of the most common types of cancer of the digestive tract. Invasion of tumor cells into surrounding tissue and metastasis are among the most significant checkpoints in tumor progression. It is known that matrix metalloproteinases (MMPs) are involved in these processes; however, knowledge of their molecular interaction networks is still limited. Investigation of these networks could provide a more comprehensive picture of the function of MMPs in tumorigenesis. Furthermore, it could be used to develop new approaches to targeted anticancer therapy. In this study, we performed microarray analysis, and 1666 genes that were aberrantly expressed in GC tissues were identified (fold change >2, P<0.05). In addition, quantitative polymerase chain reaction analysis has confirmed that MMP1, MMP3, MMP7, MMP10, MMP11 and MMP12 expression is upregulated in GC. In addition, the MMP3 expression level was negatively correlated with GC differentiation (P<0.05). By integrating the microarray information and BioGRID and STRING databases, we constructed an MMP-related molecular interaction network and observed that 18 genes (including MMPs) were highly expressed in GC tissues. The most enriched of these 18 genes in the Gene Oncology (GO) and pathway analysis were in extracellular matrix disassembly (GO biological process) and extracellular matrix-receptor interaction (KEGG pathway), which are closely correlated with cancer invasion and metastasis. Collectively, our results suggest that the MMP-related interaction network has a role in GC progression, and therefore further studies are required in order to investigate these network interactions in tumorigenesis.

SPOCK1 promotes tumor growth and metastasis in human prostate cancer

Prostate cancer is the most diagnosed noncutaneous cancer and ranks as the second leading cause of cancer-related deaths in American males. Metastasis is the primary cause of prostate cancer mortality. Survival rate is only 28% for metastatic patients, but is nearly 100% for patients with localized prostate cancers. Molecular mechanisms that underlie this malignancy remain obscure, and this study investigated the role of SPARC/osteonectin, cwcv, and kazal-like domain proteoglycan 1 (SPOCK1) in prostate cancer progression. Initially, we found that SPOCK1 expression was significantly higher in prostate cancer tissues relative to noncancerous tissues. In particular, SPOCK1 expression was also markedly high in metastatic tissues compared with nonmetastatic cancerous tissues. SPOCK1 expression knockdown by specific short hairpin RNA in PC3 cells was significantly inhibited, whereas SPOCK1 overexpression in RWPE-1 cells promoted cell viability, colony formation in vitro, and tumor growth in vivo. Moreover, the SPOCK1 knockdown in PC3 cells was associated with cell cycle arrest in G₀/G₁ phase, while the SPOCK1 overexpression in RWPE-1 cells induced cell cycle arrest in S phase. The SPOCK1 knockdown in PC3 cells even increased cell apoptosis. SPOCK1 modulation was also observed to affect cancerous cell proliferation and apoptotic processes in the mouse model of prostate cancer. Additionally, the SPOCK1 knockdown decreased, whereas the SPOCK1 overexpression increased cell migration and invasion abilities in vitro. Injection of SPOCK1-depleted PC3 cells significantly decreased metastatic nodules in mouse lungs. These findings suggest that SPOCK1 is a critical mediator of tumor growth and metastasis in prostate cancer.

MicroRNA profile of tumorigenic cells during carcinogenesis of lung adenocarcinoma

To obtain microRNA (miRNA) profile and clarify their biological function in tumorigenic Sca-1(+) CD34(+) cells during carcinogenesis of lung adenocarcinoma. After intranasal infection with recombinant Adeno-Cre viruses (AdV-Cre), lung adenocarcinoma was identified pathologically in Lox-stop-lox Kras (LSL-Kras) G12D mice. Sca-1(+) CD34(+) cells were sorted by flow cytometry and tested for tumor-initiating ability, self-renewal and tumorigenicity. MiRNA profiles were obtained using microarray and further confirmed by real-time RT-PCR (qRT-PCR). MiRNA functions were predicted bioinformatically, and miR-294 function was verified to explore its role in tumor migration and invasion. Lung adenocarcinoma was induced in LSL-Kras G12D mice within 30 days. In vivo, the tumorigenicity of Sca-1(+) CD34(+) cells was 25 times stronger than Sca-1(-) CD34(-) cells. During tumorigenesis of lung adenocarcinoma, the expression of 145 miRNAs in Sca-1(+) CD34(+) cells increased and 72 miRNAs decreased (P < 0.01). Four successively up-regulated miRNAs (miR-15a*, miR-203, miR-294 and miR-295*) and three successively down-regulated ones (miR-19b, miR-483 and miR-615-5p) were identified. Among them, miR-294 could constitutively bind to 3'-UTR of matrix metalloproteinase 3 (MMP3), and down-regulate MMP3 protein expression. MiR-294 also significantly inhibited migration and invasion of Lewis lung cancer cells. MiRNAs are characteristically expressed in tumor-initiating Sca-1(+) CD34(+) cells of lung adenocarcinoma, and may play important roles during the carcinogenesis of lung adenocarcinoma.

Androgen receptor in hepatocarcinogenesis: Recent developments and perspectives

Previous studies have indicated that males are at a higher risk of developing hepatocellular carcinoma (HCC) compared with females. Identifying the factors that cause this gender-specific difference in the incidence of HCC has long been considered important for revealing the molecular mechanisms involved in hepatocarcinogenesis. Given the unprecedented tools that are now available for molecular research, genetic studies have established that the androgen receptor (AR) may be partly responsible for gender disparity in HCC. AR has a dual role, promoting HCC initiation and development, as well as suppressing HCC metastasis. The present review provides an overview of the involvement of AR signaling in HCC. The review highlighted important studies, examples of the direct AR transcriptional target genes involved in HCC and novel theories concerning the conventional concept, suggesting that targeting the AR, rather than the androgen, may provide an improved therapeutic approach for the treatment of HCC.

Cyclophilin inhibition as potential therapy for liver diseases

The cyclophilins are a group of proteins with peptidyl-prolyl isomerase enzymatic activity, localised in different cellular compartments and involved in a variety of functions related to cell metabolism and energy homeostasis, having enhanced expression in inflammation or malignancy. Cyclophilin A (CypA), the most abundantly expressed cyclophilin, is present mainly in the cytoplasm and is a host factor involved in the life cycle of multiple viruses. The extracellular fractions of CypA and CypB are potent pro-inflammatory mediators. CypD, located in mitochondria, is a key regulator of mitochondrial permeability transition pores, and is critical for necrotic cell death. Cyclosporines are the prototype cyclophilin inhibitors. Cyclic peptides, which bind and inhibit cyclophilins without having immunosuppressive properties, have been generated by chemical modifications of cyclosporin A. In addition, cyclophilin inhibitors that are structurally different from cyclosporines have been synthesized. The involvement of cyclophilins in the pathogenesis of different liver diseases has been established using both in vitro and in vivo investigations, thus indicating that cyclophilin inhibition may be of therapeutic benefit. This review summarises the evidence for potential therapeutic applications of non-immunosuppressive cyclophilin inhibitors, alone or in combination with other agents, in virus-induced liver diseases like hepatitis C, B or Delta, liver inflammation and fibrosis, acetaminophen-induced liver toxicity and hepatocellular carcinoma.

TIPE2 inhibits TNF-α-induced hepatocellular carcinoma cell metastasis via Erk1/2 downregulation and NF-κB activation

Tumor necrosis factor-α-induced protein 8-like 2 (TNFAIP8L2, TIPE2), which belongs to the TNF-α-induced protein 8 family, is a negative regulator of immune homeostasis. Although pro-inflammatory cytokines such as TNF-α have been reported to be involved in liver carcinoma metastasis, the effect of TIPE2 on hepatocellular carcinoma metastasis remains unknown. We demonstrate that TNF-α clearly augments MMP-13/MMP-3 expression and promotes cell migration in HepG2 cells through activation of the Erk1/2-NF-κB pathways. Interestingly, in addition to human PBLs, macrophages and fibroblasts, liver cancer cells specifically express TNF-α following LPS treatment. Most importantly, TIPE2 overexpression efficiently abrogates the effects of LPS on TNF-α secretion and abolishes the effects of TNF-α on MMP-13/MMP-3 upregulation, cell migration and Erk1/2-NF-κB activation. Taken together, these findings demonstrate that TIPE2 was able to suppress TNF-α-induced hepatocellular carcinoma metastasis by inhibiting Erk1/2 and NF-κB activation, indicating that both TNF-α and TIPE2 might be potential targets for the treatment of HCC metastasis.

Effect of ginsenoside Rh2 on the migratory ability of HepG2 liver carcinoma cells: recruiting histone deacetylase and inhibiting activator protein 1 transcription factors

In previous experiments, ginsenoside Rh2 induced apoptosis and cell cycle arrest, which indicates a potential role for ginsenoside Rh2 in anticancer treatment. The effect of ginsenoside Rh2 on cancer is marked and ginsenoside Rh2 has been shown to inhibit pancreatic tumor migratory ability. In the present study, Transwell chambers were used in order to investigate whether ginsenoside Rh2 inhibits the migratory ability of HepG2 liver carcinoma cells. Furthermore, to analyze activator protein 1 (AP-1) transcription factor expression following Rh2 treatment, ten plasmids encoding Renilla luciferase coupled to the transcription factors were transiently transfected into the HepG2 cells and luciferase was detected by the Luciferase Reporter Assay system reagent. The results indicated that ginsenoside Rh2 inhibited HepG2 cell migratory ability. The expression levels of AP-1 transcription factors were increased in HepG2 cells following induction by phorbol 12-myristate 13-acetate, but ginsenoside Rh2 suppressed this induced AP‑1 expression. AP-1 transcription factors recruit histone deacetylase (HDAC)4 and affect its transcription, thus, the expression levels of HDAC4 were also analyzed, and these were found to be increased in the Rh2 treatment group. Matrix metalloproteinase 3 (MMP3), a gene downstream of AP-1, was then investigated, and the treatment group expressed reduced levels of MMP3 gene and protein. Therefore, the inhibitory effect of ginsenoside Rh2 on the migratory ability of HepG2 may be presumed to occur by the recruitment of HDAC and the resulting inhibition of AP‑1 transcription factors, in order to reduce the expression levels of MMP3 gene and protein.

Effects of oestrogen on long noncoding RNA expression in oestrogen receptor alpha-positive ovarian cancer cells

Although oestrogen (E2) signalling has long been implicated in epithelial ovarian cancer (EOC) progression, the underlying mechanisms remain unknown. Long noncoding RNAs (lncRNAs) play a major role in cancer progression; therefore, our aim was to explore whether any lncRNA is regulated by E2 and plays some potential roles in the hormonal regulation of EOC progression. Here, we reported that E2 significantly dysregulated 115 lncRNAs (fold change ≥1.5, P<0.05) in E2 receptor (ER) alpha (ERα)-positive EOC SKOV3 cells compared with E2-untreated controls based on the microarray analysis. E2 regulation of the expression of 58 lncRNAs was bioinformatics predicted to be ERα-mediated; this was confirmed for two candidates. Both TC0101441 and TC0101686 were dysregulated by E2 in another ERα-positive PEO1 cells but not in ERα-negative A2780 cells. Additionally, the modulation of TC0101441 and TC0101686 expression by E2 was abrogated by the ER inhibitor ICI 182, 780 and short hairpin RNAs targeting ERα (ERα-shRNA). Further study of the two lncRNA expression indicated that ERα-positive EOC tissues had lower expression of TC0101686 and higher expression of TC0101441 compared to ERα-negative tissues. Particularly, elevated TC0101441 expression was correlated with lymph node metastasis, showing a metastatic potential. Results of in vitro assays further confirmed the pro-metastatic effect of TC0101441 and revealed that knockdown of TC0101441 also impaired E2-induced EOC cell migration/invasion by at least partly, regulating MMP2 and MMP3. Together, our findings demonstrate, for the first time, that E2 modulates lncRNA expression in ERα-positive EOC cells and that this regulation is sometimes ERα-mediated. Furthermore, our findings reveal that TC0101441contributes to E2-induced EOC cell migration/invasion. These results may shed a new insight into estrogenic effect on EOC progression by providing a perspective of lncRNA.

Overexpression of long non-coding RNA HOTAIR predicts poor patient prognosis and promotes tumor metastasis in epithelial ovarian cancer

OBJECTIVES

Although long non-coding RNAs (lncRNAs) are emerging as new regulators in the cancer paradigm, the involvement of lncRNAs in epithelial ovarian cancer (EOC) is just beginning to be studied. In this study, we focused on lncRNA HOX transcript antisense RNA (HOTAIR) and investigated its expression pattern, clinical significance, and biological function in EOC.

METHODS

HOTAIR expression in EOC tissues was examined and its correlation with clinicopathological factors and patient prognosis was analyzed. A series of in vitro and in vivo assays were performed to understand the role of HOTAIR in EOC metastasis.

RESULTS

HOTAIR expression was elevated in EOC tissues, and HOTAIR levels were highly positively correlated with the FIGO stage, the histological grade of the tumor, lymph node metastasis, and reduced overall survival (OS) and disease-free survival (DFS). A multivariate analysis showed that HOTAIR expression is an independent prognostic factor of OS and DFS in patients with EOC. Additionally, the results of in vitro assays showed that the suppression of HOTAIR expression in the three highly metastatic EOC cell lines (SKOV3.ip1, HO8910-PM, and HEY-A8) significantly reduced cell migration/invasion. The results of in vivo assays further confirmed the pro-metastatic effects of HOTAIR. Moreover, the pro-metastatic effects of HOTAIR were partially mediated by the regulation of certain matrix metalloproteinases (MMPs) and epithelial-to-mesenchymal transition (EMT)-related genes.

CONCLUSIONS

Our data suggest that HOTAIR plays a vital role in EOC metastasis and could represent a novel prognostic marker and potential therapeutic target in patients with EOC.

Expression and prognostic relevance of cyclophilin A and matrix metalloproteinase 9 in esophageal squamous cell carcinoma

Aims

To guide clinicians in selecting treatment options for esophageal squamous cell carcinoma (ESCC) patients, reliable markers predictive of clinical outcome are desirable. This study analyzed the correlation of cyclophilin A (CypA) and matrix metalloproteinase 9 (MMP9) in ESCC and their relationships to clinicopathological features and survival.

Methods

We immunohistochemically investigated 70 specimens of ESCC tissues using CypA and MMP9 antibodies. Then, the correlations between CypA and MMP9 expression and clinicopathological features and its prognostic relevance were determined.

Results

Significant correlations were only found in high level of CypA and MMP9 expression with tumor differentiation and lymph node status. Significant positive correlations were found between the expression status of CypA and that of MMP9. Overexpression of CypA and metastasis were significantly associated with shorter progression free survival times in univariate analysis. Multivariate analysis confirmed that CypA expression was an independent prognostic factor.

Conclusions

CypA might be correlated with the differentiation, and its elevated expression may be an adverse prognostic indicator for the patients of ESCC. CypA/MMP9 signal pathway may be attributed to the malignant transformation of ESCC, and attention should be paid to a possible target for therapy.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1166551968105508.

Proteomic identification of target proteins following Drosha knockdown in cervical cancer

The nuclear microRNA (miRNA) processing enzyme Drosha is upregulated in cervical cancer, and its overexpression is related to an invasive tumour phenotype. However, the mechanisms that underlie this effect remain poorly understood. The aim of this study was to identify the potential targets of Drosha in cervical cancer. Here, we demonstrated that Drosha knockdown (Drosha-KD) inhibited proliferation, colony formation and the migration of cervical cancer cells in vitro. A global upregulation of proteins in Drosha-KD cells was revealed by two-dimensional gel electrophoresis (2-DE). Eighteen proteins were identified by liquid chromatography and tandem mass spectrometry technology (LC-MS/MS) from 21 selected protein spots that exhibited significant alterations in Drosha-KD cells. The majority of the identified proteins have been previously associated with tumour formation. The downregulation of tubulin 5β in Drosha-KD cervical cancer cells was further confirmed by western blotting. Our results suggest that Drosha affects the biological activity of cervical cancer cells by regulating the expression of numerous tumour-associated proteins.

Thyroid hormone receptor represses miR-17 expression to enhance tumor metastasis in human hepatoma cells

MicroRNAs (miRNAs) are thought to control tumor metastasis through direct interactions with target genes. Thyroid hormone (T3) and its receptor (TR) are involved in cell growth and cancer progression. However, the issue of whether miRNAs participate in T3/TR-mediated tumor migration is yet to be established. In the current study, we demonstrated that T3/TR negatively regulates mature miR-17 transcript expression, both in vitro and in vivo. Luciferase reporter and chromatin immunoprecipitation (ChIP) assays localized the regions responding to TR-mediated repression to positions -2234/-2000 of the miR-17 promoter sequence. Overexpression of miR-17 markedly inhibited cell migration and invasion in vitro and in vivo, mediated via suppression of matrix metalloproteinases (MMP)-3. Moreover, p-AKT expression was increased in miR-17-knockdown cells that led to enhanced cell invasion, which was blocked by LY294002. Notably, low miR-17 expression was evident in highly metastatic cells. The cell migration ability was increased by T3, but partially reduced upon miR-17 overexpression. Notably, TRα1 was frequently upregulated in hepatocellular carcinoma (HCC) samples and associated with low overall survival (P=0.023). miR-17 expression was significantly negatively associated with TRα1 (P=0.033) and MMP3 (P=0.043) in HCC specimens. Data from our study suggest that T3/TR, miR-17, p-AKT and MMP3 activities are interlinked in the regulation of cancer cell metastasis.

Cyclophilin A enhances cell proliferation and tumor growth of liver fluke-associated cholangiocarcinoma

Background

Cyclophilin A (CypA) expression is associated with malignant phenotypes in many cancers. However, the role and mechanisms of CypA in liver fluke-associated cholangiocarcinoma (CCA) are not presently known. In this study, we investigated the expression of CypA in CCA tumor tissues and CCA cell lines as well as regulation mechanisms of CypA in tumor growth using CCA cell lines.

Methods

CypA expression was determined by real time RT-PCR, Western blot or immunohistochemistry. CypA silence or overexpression in CCA cells was achieved using gene delivery techniques. Cell proliferation was assessed using MTS assay or Ki-67 staining. The effect of silencing CypA on CCA tumor growth was determined in nude mice. The effect of CypA knockdown on ERK1/2 activation was assessed by Western blot.

Results

CypA was upregulated in 68% of CCA tumor tissues. Silencing CypA significantly suppressed cell proliferation in several CCA cell lines. Likewise, inhibition of CypA peptidyl-prolyl cis-trans isomerase (PPIase) activity using cyclosporin A (CsA) decreased cell proliferation. In contrast, overexpression of CypA resulted in 30% to 35% increases in proliferation of CCA cell lines. Interestingly, neither silence nor overexpression of CypA affected cell proliferation of a non-tumor human cholangiocyte cell line, MMNK1. Suppression of CypA expression attenuated ERK1/2 activity in CCA M139 cells by using both transient and stable knockdown methods. In the in vivo study, there was a 43% reduction in weight of tumors derived from CypA-silenced CCA cell lines compared with control vector CCA tumors in mice; these tumors with stable CypA silencing showed a reduced cell proliferation.

Conclusions

CypA is upregulated in majority of CCA patients' tissues and confers a significant growth advantage in CCA cells. Suppression of CypA expression decreases proliferation of CCA cell lines in vitro and reduces tumor growth in the nude mouse model. Inhibition of CypA activity also reduces CCA cell proliferation. The ERK1/2 pathway may be involved in the CypA-mediated CCA cell proliferation. Thus, CypA may represent an important new therapeutic target for liver fluke-associated CCA.