Decreased expression of decorin and p57(KIP2) correlates with poor survival and lymphatic metastasis in lung cancer patients

CIP/KIP and INK4 families as hostages of oncogenic signaling

CIP/KIP and INK4 families of Cyclin-dependent kinase inhibitors (CKIs) are well-established cell cycle regulatory proteins whose canonical function is binding to Cyclin-CDK complexes and altering their function. Initial experiments showed that these proteins negatively regulate cell cycle progression and thus are tumor suppressors in the context of molecular oncology. However, expanded research into the functions of these proteins showed that most of them have non-canonical functions, both cell cycle-dependent and independent, and can even act as tumor enhancers depending on their posttranslational modifications, subcellular localization, and cell state context. This review aims to provide an overview of canonical as well as non-canonical functions of CIP/KIP and INK4 families of CKIs, discuss the potential avenues to promote their tumor suppressor functions instead of tumor enhancing ones, and how they could be utilized to design improved treatment regimens for cancer patients.

Identification of Clinical and Tumor Microenvironment Characteristics of Hypoxia-Related Risk Signature in Lung Adenocarcinoma

Background: Lung cancer is the leading cause of cancer-related death globally. Hypoxia can suppress the activation of the tumor microenvironment (TME), which contributes to distant metastasis. However, the role of hypoxia-mediated TME in predicting the diagnosis and prognosis of lung adenocarcinoma (LUAD) patients remains unclear.

Methods: Both RNA and clinical data from the LUAD cohort were downloaded from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. Both univariate and multivariate Cox regression analyses were used to further screen prognosis-related hypoxia gene clusters. Time-dependent receiver operation characteristic (ROC) curves were established to evaluate the predictive sensitivity and specificity of the hypoxia-related risk signature. The characterization of gene set enrichment analysis (GSEA) and TME immune cell infiltration were further explored to identify hypoxia-related immune infiltration.

Results: Eight hypoxia-related genes (LDHA, DCN, PGK1, PFKP, FBP1, LOX, ENO3, and CXCR4) were identified and established to construct a hypoxia-related risk signature. The high-risk group showed a poor overall survival compared to that of the low-risk group in the TCGA and GSE68465 cohorts (p < 0.0001). The AUCs for 1-, 3-, and 5-year overall survival were 0.736 vs. 0.741, 0.656 vs. 0.737, and 0.628 vs. 0.649, respectively. The high-risk group was associated with immunosuppression in the TME.

Conclusion: The hypoxia-related risk signature may represent an independent biomarker that can differentiate the characteristics of TME immune cell infiltration and predict the prognosis of LUAD.

Decorin Suppresses Invasion and EMT Phenotype of Glioma by Inducing Autophagy via c-Met/Akt/mTOR Axis

Decorin exhibits inhibitory effects in tumorigenesis in various types of cancers. The clinical characteristics of 42 patients with GBM were reviewed and analyzed. Lentiviral constructs for decorin overexpression and shRNA-mediated silencing were established for U87MG cells and T98G cells, respectively. The expressions of EMT- and autophagy-associated markers were detected in GBM cell lines. The migration and invasion of the glioma cells were assayed to reflect the malignant behavior of GBM. A mouse xenograft model was used to verify the effect of decorin on autophagy in vivo. Reduced expression of decorin in glioma tissues was associated with a poor survival of the patients. Decorin overexpression suppressed cell migration, invasion and attenuated EMT phenotype in glioma cell lines. Further study indicated that decorin inhibited EMT phenotype through the induction of autophagy. The mechanisms include inhibiting the activation of c-Met/Akt/mTOR signaling and regulating the expressions of mesenchymal markers including Slug, vimentin and Twist, and epithelial marker E-cadherin. In addition, decorin overexpression in a mice model can also suppress the GBM invasion and EMT phenotype. In conclusion, decorin suppresses invasion and EMT phenotype of glioma by inducing autophagy via c-Met/Akt/mTOR axis.

Immunohistochemical expression of cyclin-dependent kinase inhibitors p16 and p57 in rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a highly malignant cancer and is the most common soft tissue sarcoma in children and adolescents, but it is rare in adults (<1% of all adult malignancies). Altered expression and molecular abnormalities of cell-cycle-regulatory proteins are one of the most prominent features in RMS. Therefore, we evaluated the expression of cyclin-dependent kinase inhibitors p57 and p16, as well as p16 methylation status, along with clinicopathological characteristics and overall survival (OS) in RMS patients. This analysis was conducted on 23 pediatric and 44 adult patients. There was a male predominance in both groups and extremities were the most frequent tumor site. In adults, alveolar and pleomorphic types were almost equally represented. The majority of pediatric tumors were low grade, whereas, in adults, only one patient had a low-grade tumor. Seven pediatric (30.43%) and eight adult (18.18%) patients had a low p16 expression. The analysis of methylation status of the p16 promoter showed the presence of methylated allele only in one sample with pleomorphic histology. Six (26.1%) pediatric and 15 (34.1%) adult patients had low p57 expression, while in 17 (73.9%) pediatric and 29 (65.9%) adult patients it was assessed as high. Ninetyone percent of the pediatric patients and 32.6% of adults were alive at the end of the observational period. In adults, significant associations were found between OS and age (P = 0.020), gender (P = 0.027), tumor size (P < 0.001), lymph node status (P < 0.001), presence of metastases (P = 0.015), and p57 expression (P = 0.039). Stratification by histological type showed the correlation of low p57 expression (P = 0.030) and worse OS of patients with alveolar RMS. Univariate analysis identified age > 50 yrs. (HR 2.447), tumors > 5 cm (HR 21.31), involvement of regional lymph nodes (HR 3.96), the presence of metastases (HR 2.53), and low p57 expression (HR 2.11) as predictors of lower OS. Tumor size, regional lymph nodes involvement, and metastases were the independent predictors after multivariate analysis, while p57 did not predict OS in an independent way. In summary, although p57 was not confirmed to be an independent predictor of OS, our results indicate that its low expression may be the marker of aggressive phenotype and poor prognosis in adult RMS patients. Also, our findings suggest that epigenetic inactivation of p16 is not important in the pathogenesis of rhabdomyosarcoma.

KRT8 and KRT19, associated with EMT, are hypomethylated and overexpressed in lung adenocarcinoma and link to unfavorable prognosis

Background: Lung adenocarcinoma (LUAD) is the most common histological type of lung cancer. To date, the prognosis of patients with LUAD remains dismal. Methods: Three datasets were downloaded from the GEO database. Differentially expressed genes (DEGs) were obtained. FunRich was used to perform pathway enrichment analysis. Protein–protein interaction (PPI) networks were established and hub genes were obtained by Cytoscape software. GEPIA was utilized to conduct correlation and survival analysis. Upstream miRNAs of DEGs were predicted via miRNet database, and methylation status of promoters of DEGs was determined through UALCAN database. Results: A total of 375 DEGs, including 105 and 270 up-regulated and down-regulated genes in LUAD, were commonly appeared in three datasets. These DEGs were significantly enriched in mesenchymal-to-epithelial transition (MET) and epithelial-to-mesenchymal transition (EMT). About 8 up-regulated and 5 down-regulated DEGs were commonly appeared in EMT/MET-related gene set and the top 50 hub gene set. Among the 13 genes, increased expression of KRT8 and KRT19 indicated unfavorable prognosis whereas high expression of DCN and CXCL12 suggested favorable prognosis in LUAD. Correlation analysis showed that KRT8 (DCN) expression was linked to KRT19 (CXCL12) expression. Further analysis displayed that KRT8 and KRT19 could jointly forecast poor prognosis in LUAD. About 42 and 2 potential miRNAs were predicted to target KRT8 and KRT19, respectively. Moreover, methylation level analysis demonstrated that KRT8 and KRT19 were significantly hypomethylated in LUAD compared with normal controls. Conclusions: All these findings suggest that KRT8 and KRT19 are hypomethylated and overexpressed in LUAD and associated with unfavorable prognosis.

Prediction of Lymph-Node Metastasis in Cancers Using Differentially Expressed mRNA and Non-coding RNA Signatures

Accurate prediction of lymph-node metastasis in cancers is pivotal for the next targeted clinical interventions that allow favorable prognosis for patients. Different molecular profiles (mRNA and non-coding RNAs) have been widely used to establish classifiers for cancer prediction (e.g., tumor origin, cancerous or non-cancerous state, cancer subtype). However, few studies focus on lymphatic metastasis evaluation using these profiles, and the performance of classifiers based on different profiles has also not been compared. Here, differentially expressed mRNAs, miRNAs, and lncRNAs between lymph-node metastatic and non-metastatic groups were identified as molecular signatures to construct classifiers for lymphatic metastasis prediction in different cancers. With this similar feature selection strategy, support vector machine (SVM) classifiers based on different profiles were systematically compared in their prediction performance. For representative cancers (a total of nine types), these classifiers achieved comparative overall accuracies of 81.00% (67.96-92.19%), 81.97% (70.83-95.24%), and 80.78% (69.61-90.00%) on independent mRNA, miRNA, and lncRNA datasets, with a small set of biomarkers (6, 12, and 4 on average). Therefore, our proposed feature selection strategies are economical and efficient to identify biomarkers that aid in developing competitive classifiers for predicting lymph-node metastasis in cancers. A user-friendly webserver was also deployed to help researchers in metastasis risk determination by submitting their expression profiles of different origins.

Roles of Proteoglycans and Glycosaminoglycans in Cancer Development and Progression

The extracellular matrix (ECM) spatiotemporally controls cell fate; however, dysregulation of ECM remodeling can lead to tumorigenesis and cancer development by providing favorable conditions for tumor cells. Proteoglycans (PGs) and glycosaminoglycans (GAGs) are the major macromolecules composing ECM. They influence both cell behavior and matrix properties through direct and indirect interactions with various cytokines, growth factors, cell surface receptors, adhesion molecules, enzymes, and glycoproteins within the ECM. The classical features of PGs/GAGs play well-known roles in cancer angiogenesis, proliferation, invasion, and metastasis. Several lines of evidence suggest that PGs/GAGs critically affect broader aspects in cancer initiation and the progression process, including regulation of cell metabolism, serving as a sensor of ECM's mechanical properties, affecting immune supervision, and participating in therapeutic resistance to various forms of treatment. These functions may be implemented through the characteristics of PGs/GAGs as molecular bridges linking ECM and cells in cell-specific and context-specific manners within the tumor microenvironment (TME). In this review, we intend to present a comprehensive illustration of the ways in which PGs/GAGs participate in and regulate several aspects of tumorigenesis; we put forward a perspective regarding their effects as biomarkers or targets for diagnoses and therapeutic interventions.

Decorin concentrations in canine normal and neoplastic mammary gland tissues

In the present study, the concentration of decorin in canine normal and neoplastic mammary gland tissues was examined to understand the potential role of decorin in development and progression of canine mammary tumours. The homogenates of 48 mammary gland tumours (10 benign and 38 malignant) and 10 samples of normal canine mammary gland tissue were used in the study. The presence and quantification of decorin was examined in the homogenates using Western blot and specific canine ELISA. Western blotting confirmed the presence of decorin both in the normal mammary gland tissues and in the mammary gland tumours. The concentration of decorin was significantly higher (p < .05) in the benign tumours and non-metastatic malignant tumours than in the normal mammary gland. The concentration of decorin was significantly lower (p < .05) in the malignant tumours with metastasis to regional lymph nodes compared with benign tumours and non-metastatic malignant tumours. No significant differences were found in the level of decorin between the benign and the non-metastatic malignant tumours. Both the histological type of malignant tumours and the histological grade did not significantly affect the concentration of decorin. These findings suggest that neoplastic transformation in the canine mammary gland leads to increase in the decorin protein synthesis. The reducing decorin concentration in canine malignant mammary tumours appears to facilitate the metastatic spread of these tumours.

Decorin as a prognostic biomarker in patients with malignant peripheral nerve sheath tumors

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive soft-tissue sarcomas. The prognosis of MPNSTs has been reported to differ among previous studies. However, there have been a number of reported prognostic biomarkers associated with MPNSTs. In the present study, a proteomics study was performed to discover the differential protein expression in patients with MPSNTs with different prognoses. The clinical data of 30 primary extremities of patients with MPNSTs, who underwent surgery at the Department of Hand Surgery, Huashan Hospital, Fudan University between January 2002 and December 2011, were acquired. A total of 16 patients succumbed to their diseases within 5 years, whereas 14 patients were disease-free for >5 years. Samples from the 9 patients who succumbed within 2 years were assigned to Group D, while samples from the 8 patients who were continuously disease-free for >5 years following diagnosis were assigned to Group L for the proteomics study. Label-free quantitative proteomics and mass spectrometry were performed to filtrate differential protein in patients with MPSNTs with different prognoses. Decorin was filtrated as a differential protein of note. The expression level of decorin was significantly lower in Group D compared with that in Group L (D/L=0.0948; P=0.0004). The result was verified by immunohistochemical staining in the 30 primary extremities of patients with MPNSTs. The 5-year survival rate of patients with positive expression of decorin was 78.57%, while the 5-year survival rate of patients negative for decorin expression was 18.75% (P=0.0014). Overall, a high level of decorin indicted a better prognosis in patients with MPNSTs. With further investigation, decorin may be a reliable prognostic biomarker for MPNSTs.

Small Leucine Rich Proteoglycans (decorin, biglycan and lumican) in cancer

The extracellular matrix (ECM) prevents invasion of tumour cells and possesses an intrinsic mechanism to down-regulate signalling processes that promote cancer proliferation. Small Leucine Rich Proteoglycans (SLRPs) are ubiquitous ECM components involved in matrix structural organization and as such can potentially regulate cancer cell multiplication, angiogenesis and migration. Decorin, a class I SLRP that modulates collagen fibrillogenesis, also functions as a natural pan-tyrosine kinase inhibitor to reduce tumour growth. In fact, decreased decorin expression has been associated with tumour aggressiveness and lower survival. In contrast, biglycan, another class I SLRP, was highly expressed in cancer and was associated with metastatic activity and lower survival. Tissue expression of lumican, a class II SLRP, was associated with clinical outcome and appears tumour specific. Recently, decorin, biglycan and lumican were found to be potential biomarkers in bladder cancer. This review updates our current understanding on the molecular interplay and significance of decorin, biglycan and lumican expression in cancer.

Stathmin overexpression is associated with growth, invasion and metastasis of lung adenocarcinoma

Stathmin has been investigated as a tumor biomarker because it appear to be associated with tumorigenesis; however, the effect of stathmin in lung adenocarcinoma (LAC) remains poorly understood. The purpose of this study was to examine the expression of stathmin in lung adenocarcinoma, and to disclose the relationship between them. The expression of stathmin was examined by RT-PCR, IHC and Western blot. Furthermore, small interfering RNA (shRNA)-mediated silencing of stathmin was employed in LAC cells to investigate cell proliferation, invasion and apoptosis. In this study, we showed that overexpression of stathmin was significantly associated with poorly differentiated, lymph node metastasis and advance TNM stages of lung adenocarcinoma. And silencing of stathmin expression inhibited the proliferation, migration and invasion of lung adenocarcinoma PC-9 cells, and retarded the growth of PC-9 cells xenografts in nude mice. Additionally, the anticarcinogenic efficacy of stathmin silencing might be involved in P38 and MMP2 signaling pathways. In conclusion, these results showed that stathmin expression was significantly up-regulated in LAC, which may act as a biomarker for LAC. Furthermore, silence of stathmin inhibiting LAC cell growth indicated that stathmin may be a promising molecular target for LAC therapy.

Overexpression of EMMPRIN is associated with lymph node metastasis and advanced stage of non-small cell lung cancer: a retrospective study

Background

Previous studies show that overexpression of EMMPRIN involved in the malignant biological behavior of tumors. This investigation was to disclose the expression status of EMMPRIN in non-small cell lung cancer (NSCLC) and its clinical value for the diagnosis of NSCLC.

Methods

The expression of EMMPRIN was examined using immunohistochemistry and enzyme-linked immunosorbent assay. The clinical value of EMMPRIN was evaluated by drawing a receiver operating characteristic (ROC) curve.

Results

NSCLC tissues and serum exhibited higher expression levels of EMMPRIN than the normal control (p < 0.05), and the expression of the EMMPRIN was significantly associated with lymphatic invasion and advanced stage of NSCLC (p < 0.05). ROC curve suggested that the threshold level of serum EMMPRIN for distinguishing NSCLC from control group was 80.3 pg/mL, and displayed a sensitivity of 97.22% and a specificity of 95%. And higher EMMPRIN expression in serum and tissues appeared to be risk factors for NSCLC development (risk ratio =1.56 and 1.1).

Conclusion

Overexpression of EMMPRIN was associated with lymphatic metastasis and advanced stage of NSCLC and test of serum EMMPRIN contributes to the NSCLC diagnosis.

Increased HSP27 correlates with malignant biological behavior of non-small cell lung cancer and predicts patient's survival

Heat shock protein 27 (HSP27) has been found to be related to tumorigenesis. The aim of this study was to investigate the expression pattern and clinical significance of HSP27 in non-small-cell lung cancer (NSCLC). The expression of HSP27 in tissues was examined by immunohistochemistry and serum level of HSP27 mRNA was detected by real-time PCR. The survival analysis was performed by a Kaplan Meier method and the estimation of risk factors was determined by the multiple regression analysis. The expression of HSP27 was increased in lung cancer tissues (p < 0.001) and serum (p < 0.001) of NSCLC patients and higher HSP27 in lung cancer tissues and serum of NSCLC patients was associated with poorly differentiated cancer (p < 0.001; p = 0.035), lymphatic metastasis (p < 0.001; p < 0.001), advanced TNM stage (p < 0.001; p < 0.001). And the levels of HSP27 in tissues and serum of lung cancer patients had a certain positive correlation (p = 0.046). Moreover, increased HSP27 expression correlated with shorter survival of NSCLC patients (p < 0.001). The results suggest that HSP27 may serve as a potential biomarker for diagnosis and prognosis of NSCLC.

Increased AAA-TOB3 correlates with lymph node metastasis and advanced stage of lung adenocarcinoma

BACKGROUND

This study was to investigate the differential mitochondrial protein expressions in human lung adenocarcinoma and provide preliminary data for further exploration of the carcinogenic mechanism.

METHODS

Total proteins of A549 and 16HBE mitochondria were extracted through 2D polyacrylamide gel electrophoresis (2-DE). The differential mitochondria proteins were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and were further confirmed by Western blot, immunoelectron microscopy and immunohistochemistry (IHC) in A549 cells as well as lung adenocarcinoma tissues.

RESULTS

A total of 41 differentially expressed protein spots were found in A549 mitochondria. Of them, 15 proteins were highly expressed and 26 proteins were lowly expressed in the mitochondria of A549 (by more than 1.5 times). Among the 15 more highly expressed proteins, AAA-TOB3 (by more than 3 times) was highly expressed in the mitochondria of A549 compared with the 16HBE, by LC-MS/MS identification. High electron density and clear circular colloidal gold-marked AAA-TOB3 particles were observed in the A549 cells via immunoelectron microscopy. Besides, AAA-TOB3 was confirmed to be elevated in lung adenocarcinoma by Western blot and IHC. Moreover, increased AAA-TOB3 correlated with lymph node metastasis and advanced stage of lung adenocarcinoma (p<0.05).

CONCLUSIONS

AAA-TOB3 was highly expressed in lung adenocarcinoma, and the up-regulation of AAA-TOB3 correlated with lymph node metastasis and advanced stage of lung adenocarcinoma, which suggested that it could serve as a potential molecular marker for lung adenocarcinoma.

Decorin gene upregulation mediated by an adeno-associated virus vector increases intratumoral uptake of nab-paclitaxel in neuroblastoma via inhibition of stabilin-1

The availability of effective medication for the treatment of refractory or recurrent neuroblastoma remains limited. This study sought to investigate the effects of increased decorin (DCN) expression on the intratumoral uptake of nab-paclitaxel as a potential novel approach to NB. Correlation between the clinical characteristics of neuroblastoma and the expression of DCN, secreted protein acidic and rich in cysteine (SPARC) and stabilin-1 was evaluated. The anticancer effect of recombinant adeno-associated virus-DCN (rAAV-DCN) was assessed in vivo and in vitro. And the effect of rAAV-DCN on the intratumoral uptake of paclitaxel was also studied in neuroblastoma-grafted nude mice. Overall, 12.5%, 17.7%, and 71.9% of the tumors stained positive for DCN, SPARC and stabilin-1 respectively and correlated to age, stage and N-MYC status in 96 children and adolescents with neuroblastoma. Transfected neuroblastoma cells stably expressed DCN, with in vivo and in vitro studies demonstrating rAAV-DCN sensitized the anticancer effect of nab-paclitaxel. Systemic rAAV-DCN in neuroblastoma-grafted nude mice inhibited stabilin-1, up-regulated SPARC, and increased the intratumoral uptake of paclitaxel. Macrophage depletion or anti-stabilin-1 monoclonal antibody increased the intratumoral uptake of nab-paclitaxel and its anticancer effects to a degree comparable to that achieved by systemic rAAV-DCN. The systemic administration of rAAV-DCN up-regulates DCN in neuroblastoma and accelerates the intratumoral uptake of nab-paclitaxel by inhibiting stabilin-1 mediated SPARC degradation.

Reduced decorin expression in the tumor stroma correlates with tumor proliferation and predicts poor prognosis in patients with I-IIIA non-small cell lung cancer

Decorin, chiefly synthesized by tumor stroma, is known as a tumor suppressor. However, the clinical and prognostic significance in lung cancer remained unclear. Here, decorin and Ki67 expression was detected by immunohistochemistry (IHC) in I-IIIA non-small cell lung cancer (NSCLC) tissues (n = 264) in comparison to adjacent normal tissues (n = 40). The relationship between the expression of decorin and clinical characteristics, as well as Ki67 index and prognosis, was analyzed. Decorin expression was decreased in both the stroma (P < 0.001) and the tumor cells (P = 0.038) in NSCLC specimens. There was the lowest stromal expression of decorin in patients with G3 adenocarcinoma and higher Ki67 index in the stromal decorin-negative group. The Kaplan-Meier survival analysis demonstrated that lack of decorin in the stroma was correlated with a shorter DFS and OS (P = 0.005 and P = 0.010, respectively), while there was no significant association between decorin expression in the tumor cells and outcome. Multivariate analysis showed that reduced expression of decorin in the stroma was an independent prognostic factor for poor outcome including DFS (HR = 5.685, 95 % CI 0.493-0.933; P = 0.017) and OS (HR = 6.579, 95 % CI 0.484-0.908; P = 0.010). Negative decorin in the stroma combined with high Ki67 index predicted poorer outcomes for I-IIIA NSCLC patients. Our results provide data on decorin expression in both the stroma and cancer cells in NSCLC and reveal that reduced expression of stromal decorin correlates with high Ki67 index and has prognostic significance for poor outcome in I-IIIA NSCLC. Our data suggest that evaluating stromal decorin expression might be useful in assessing the prognosis and malignant potential.

Matricellular proteins as regulators of cancer metastasis to bone

Metastasis is the major cause of death in cancer patients, and a frequent site of metastasis for many cancers is the bone marrow. Therefore, understanding the mechanisms underlying the metastatic process is necessary for future prevention and treatment. The tumor microenvironment is now known to play a role in the metastatic cascade, both at the primary tumor and in metastatic sites, and includes both cellular and non-cellular components. The extracellular matrix (ECM) provides structural support and signaling cues to cells. One particular group of molecules associated with the ECM, known as matricellular proteins, modulate multiple aspects of tumor biology, including growth, migration, invasion, angiogenesis and metastasis. These proteins are also important for normal function in the bone by regulating bone formation and bone resorption. Recent studies have described a link between some of these proteins and metastasis of various tumors to the bone. The aim of this review is to summarize what is currently known about matricellular protein influence on bone metastasis. Particular attention to the contribution of both tumor cells and non-malignant cells in the bone has been given.

Prognostic value of stromal decorin expression in patients with breast cancer: a meta-analysis

BACKGROUND

Numbers of studies have investigated the biological functions of decorin (DCN) in oncogenesis, tumor progression, angiogenesis and metastasis. Although many of them aim to highlight the prognostic value of stromal DCN expression in breast cancer, some controversial results still exist and a consensus has not been reached until now. Therefore, our meta-analysis aims to determine the prognostic significance of stromal DCN expression in breast cancer patients.

METHODS

PubMed, EMBASE, the Web of Science and China National Knowledge Infrastructure (CNKI) databases were searched for full-text literatures met out inclusion criteria. We applied the hazard ratio (HR) with 95% confidence interval (CI) as the appropriate summarized statistics. Q-test and I(2) statistic were employed to estimate the level of heterogeneity across the included studies. Sensitivity analysis was conducted to further identify the possible origins of heterogeneity. The publication bias was detected by Begg's test and Egger's test.

RESULTS

There were three English literatures (involving 6 studies) included into our meta-analysis. On the one hand, both the summarized outcomes based on univariate analysis (HR: 0.513; 95% CI: 0.406-0.648; P<0.001) and multivariate analysis (HR: 0.544; 95% CI: 0.388-0.763; P<0.001) indicated that stromal DCN expression could promise the high cancer-specific survival (CSS) of breast cancer patients. On the other hand, both the summarized outcomes based on univariate analysis (HR: 0.504; 95% CI: 0.389-0.651; P<0.001) and multivariate analysis (HR: 0.568; 95% CI: 0.400-0.806; P=0.002) also indicated that stromal DCN expression was positively associated with high disease-free survival (DFS) of breast cancer patients. No significant heterogeneity or publication bias was observed within this meta-analysis.

CONCLUSIONS

The present evidences indicate that high stromal DCN expression can significantly predict the good prognosis in patients with breast cancer. The discoveries from our meta-analysis have better be confirmed in the updated review pooling more relevant investigations in the future.

A mechanistic role for the chromatin modulator, NAP1L1, in pancreatic neuroendocrine neoplasm proliferation and metastases

Background

The chromatin remodeler NAP1L1, which is upregulated in small intestinal neuroendocrine neoplasms (NENs), has been implicated in cell cycle progression. As p57^Kip2 (CDKN1C), a negative regulator of proliferation and a tumor suppressor, is controlled by members of the NAP1 family, we tested the hypothesis that NAP1L1 may have a mechanistic role in regulating pancreatic NEN proliferation through regulation of p57^Kip2.

Results

NAP1L1 silencing (siRNA and shRNA/lipofectamine approach) decreased proliferation through inhibition of mechanistic (mammalian) target of rapamycin pathway proteins and their phosphorylation (p < 0.05) in the pancreatic neuroendocrine neoplasm cell line BON in vitro (p < 0.0001) and resulted in significantly smaller (p < 0.05) and lighter (p < 0.05) tumors in the orthotopic pancreatic NEN mouse model. Methylation of the p57^Kip2 promoter was decreased by NAP1L1 silencing (p < 0.05), and expression of p57^Kip2 (transcript and protein) was upregulated. For methylation of the p57^Kip2 promoter, NAP1L1 bound directly to the promoter (−164 to +21, chromatin immunoprecipitation). In 43 pancreatic NEN samples (38 primaries and 5 metastasis), NAP1L1 was over-expressed in metastasis (p < 0.001), expression which was inversely correlated with p57^Kip2 (p < 0.01) on mRNA and protein levels. Menin was not differentially expressed.

Conclusion

NAP1L1 is over-expressed in pancreatic neuroendocrine neoplasm metastases and epigenetically promotes cell proliferation through regulation of p57^Kip2 promoter methylation.

Loss of p57 expression and RhoA overexpression are associated with poor survival of patients with hepatocellular carcinoma

p57 and Ras homology A (RhoA) have been implicated in the growth and metastasis of several types of human cancers. This study aimed to detect their expression in hepatocellular carcinoma (HCC) tissue specimens and to determine a possible association with clinicopathological data and patient survival. A total of 80 HCC and corresponding distant normal tissue specimens were processed for immunohistochemical and qPCR analyses of p57 and RhoA expression. The data showed that expression of p57 mRNA and protein was reduced in HCC tissues when compared to that in distant non-cancer tissues (P<0.05), while expression of RhoA mRNA and protein was significantly higher in HCC tissue specimens when compared to that of the distant normal tissues. Loss of p57 expression was associated with HCC with higher α-fetoprotein (AFP) levels (>400 ng/ml; P=0.044), larger tumor size (>5 cm, P=0.004), poor tumor differentiation (P=0.020), advanced TNM stage (P=0.027), capsule invasion (P=0.018) and tumor thrombosis (P=0.008), whereas expression of RhoA protein was significantly associated with poor tumor differentiation (P=0.042), capsule invasion (P=0.022), and tumor thrombosis (P=0.002). Furthermore, there was a strong inverse relationship between p57 and RhoA expression in HCC tissues, indicating that loss of p57 expression may contribute to RhoA overexpression in HCC tissues. The median survival time of HCC patients with p57+ and p57- expression was 13.0 and 9.0 months, respectively, whereas the median survival time of HCC patients with RhoA+ and RhoA- was 9.0 and 15.0 months. Univariate analysis revealed that the levels of AFP, tumor size, TNM stage, histological grade, capsule invasion, tumor thrombosis, p57, RhoA and co-expression of p57 and RhoA were all significant prognostic indicators for overall survival of HCC patients. Multivariate analysis showed that tumor size, TNM stage, p57, RhoA and combined loss of p57 with RhoA were risk factors for poor survival of HCC patients. This study indicates that the abnormal expression of p57 and RhoA contributes to progression of HCC and poor survival of patients.

Recombinant human decorin upregulates p57KIP² expression in HepG2 hepatoma cell lines

Increasing the expression of cyclin-cyclin-dependent kinase inhibitors (cyclin-CDK) using small molecule inhibitors is a therapeutic strategy used to suppress cancer cell growth. Decorin (DCN), a functional component of the extracellular matrix, has been implicated in the suppression of cell proliferation by upregulating p21, a cyclin-CDK inhibitor. The purpose of this study was to examine the effect of recombinant decorin on the reactivation of p57KIP2, whose expression is silenced in hepatocellular carcinoma (HCC). Cell viability assay, cell cycle analysis, apoptosis assay and quantitative real time-PCR experiments were performed in three groups of HepG2 human cells: Uninfected HepG2 cells (control group), pcDNA3.1 vector-infected HepG2 cells (pcDNA3.1 group) and pcDNA3.1-DCN-infected HepG2 cells (pcDNA3.1‑DCN group). Our results revealed that recombinant human decorin inhibited cell proliferation, induced G0/G1 phase arrest and induced apoptosis by increasing the expression of caspase-3 in the pcDNA3.1-DCN group. The expression of p57KIP2 mRNA in the pcDNA3.1-DCN group was higher than in the pcDNA3.1 and control groups (P<0.05); however, there was no statistically significant difference between the control and pcDNA3.1 groups (P>0.05). In conclusion, recombinant human decorin reactivated p57KIP2 expression in HepG2 cells. As the expression level of p57KIP2 is downregulated in HCC, our finding may serve as a basis for the therapy and prognosis of HCC, although further studies are required.

Decorin interferes with platelet-derived growth factor receptor signaling in experimental hepatocarcinogenesis

Decorin, a secreted small leucine-rich proteoglycan, acts as a tumor repressor in a variety of cancers, mainly by blocking the action of several receptor tyrosine kinases such as the receptors for hepatocyte, epidermal and insulin-like growth factors. In the present study we investigated the effects of decorin in an experimental model of thioacetamide-induced hepatocarcinogenesis and its potential role in modulating the signaling of platelet-derived growth factor receptor-α (PDGFRα). Genetic ablation of decorin in mice led to enhanced tumor prevalence and a higher tumor count compared with wild-type mice. These findings correlated with decreased levels of the cyclin-dependent kinase inhibitor p21(Waf1/Cip1) and concurrent activation (phosphorylation) of PDGFRα in the hepatocellular carcinomas generated in the decorin-null vis-à-vis wild-type mice. Notably, in normal liver PDGFRα localized primarily to the membrane of nonparenchymal cells, whereas in the malignant counterpart PDGFRα was expressed by the malignant cells at their cell surfaces. This process was facilitated by a genetic background lacking endogenous decorin. Double immunostaining of the proteoglycan and the receptor revealed only minor colocalization, leading to the hypothesis that decorin would bind to the natural ligand PDGF rather than to the receptor itself. Indeed, we found, using purified proteins and immune-blot assays, that decorin binds to PDGF. Collectively, our findings support the idea that decorin acts as a secreted tumor repressor during hepatocarcinogenesis by hindering the action of another receptor tyrosine kinase, such as the PDGFRα, and could be a novel therapeutic agent in the battle against liver cancer.

More than matrix: the multifaceted role of decorin in cancer

The small leucine-rich proteoglycan, decorin, has incrementally been shown to be a powerful inhibitor of growth in a wide variety of tumour cells, an effect specifically mediated by the interaction of decorin core protein with the epidermal growth factor receptor (EGFR) and other ErbB family proteins. Nowadays, this matrikine has become the main focus of various cancer studies. Decorin is an important component of the cellular microenvironment or extracellular matrix (ECM). Its interactions with matrix and cell membrane components have been implicated in many physiological and pathophysiological processes including matrix organisation, signal transduction, wound healing, cell migration, inhibition of metastasis, and angiogenesis. This review summarises recent findings on decorin's interactions and behaviour related to cancer. Highlighted are key functions of decorin such as interaction with cell surface receptors, as well as with ECM components, and the therapeutic potential of this multifunctional molecule.

Localization of decorin gene expression in normal human breast tissue and in benign and malignant tumors of the human breast

The small extracellular matrix proteoglycan decorin which possesses a potent antitumor activity has been shown to be present in various amounts in the stroma of several tumors including those of the breast. Regarding decorin in breast malignancies the published data are conflicting, i.e., whether breast cancer cells express it or not. Here, we first compared decorin gene expression levels between healthy human breast tissue and selected types of human breast cancer using GeneSapiens databank. Next, we localized decorin mRNA in tissue specimen of normal human breast, intraductal breast papillomas and various histologic types of human breast cancer using in situ hybridization (ISH) with digoxigenin-labeled RNA probes for decorin. We also examined the effect of decorin transduction on the behavior of cultured human breast cancer MCF7 cells. Analysis of GeneSapiens databank revealed that in various human breast cancers decorin expression is significant. However, ISH results clearly demonstrated that human breast cancer cells independently of the type of the cancer do not express decorin mRNA. This was also true for papilloma-forming cells of the human breast. Indeed, decorin gene expression in healthy human breast tissue as well as in benign and malignant tumors of human breast was shown to take place solely in cells of the original stroma. Decorin transduction using decorin adenoviral vector in decorin-negative MCF7 cells resulted in a significant decrease in the proliferation of these cells and changed cell cohesion. Decorin-transduced MCF7 cells also exhibited increased apoptosis. In conclusion, our study shows that in human breast tissue only cells of the original stroma are capable of decorin gene expression. Our study also shows that transduction of decorin in decorin-negative human breast cancer cells markedly modulates the growth pattern of these cells.

Decorin protein core affects the global gene expression profile of the tumor microenvironment in a triple-negative orthotopic breast carcinoma xenograft model

Decorin, a member of the small leucine-rich proteoglycan gene family, exists and functions wholly within the tumor microenvironment to suppress tumorigenesis by directly targeting and antagonizing multiple receptor tyrosine kinases, such as the EGFR and Met. This leads to potent and sustained signal attenuation, growth arrest, and angiostasis. We thus sought to evaluate the tumoricidal benefits of systemic decorin on a triple-negative orthotopic breast carcinoma xenograft model. To this end, we employed a novel high-density mixed expression array capable of differentiating and simultaneously measuring gene signatures of both Mus musculus (stromal) and Homo sapiens (epithelial) tissue origins. We found that decorin protein core modulated the differential expression of 374 genes within the stromal compartment of the tumor xenograft. Further, our top gene ontology classes strongly suggests an unexpected and preferential role for decorin protein core to inhibit genes necessary for immunomodulatory responses while simultaneously inducing expression of those possessing cellular adhesion and tumor suppressive gene properties. Rigorous verification of the top scoring candidates led to the discovery of three genes heretofore unlinked to malignant breast cancer that were reproducibly found to be induced in several models of tumor stroma. Collectively, our data provide highly novel and unexpected stromal gene signatures as a direct function of systemic administration of decorin protein core and reveals a fundamental basis of action for decorin to modulate the tumor stroma as a biological mechanism for the ascribed anti-tumorigenic properties.

[Decorin protein is down-regulated in non-small cell lung cancer tissue and significantly associated with histological type]

BACKGROUND AND OBJECTIVE

Decorin is a protein component of the extracellular matrix. It has been proven that decorin plaid an important role in matrix assembly. The protein is also capable of suppressing tumor cell growth. The aim of this study is to examine the protein levels of decorin in tissue samples of non-small cell lung cancer (NSCLC) patients and evaluate its potential clinical value.

METHODS

Decorin protein levels in tumor tissues and corresponding normal tissues from 16 cases of lung squamous cell carcinoma (SCC) were determined by Western blot analysis. Fifty-one NSCLC samples, including both tumor and normal lung tissues, were examined by immunohistochemical (IHC) staining.

RESULTS

Western blot results showed that decorin protein levels in 75.0% (12/16) of the SCC tumor tissues were lower than those of the corresponding normal lung tissues. IHC results showed that positively stained decorin was detected in only 11.8% of the tumor tissues, significantly lower than that observed in normal alveoli tissues (53.1%, P<0.001). In lung adenocarcinoma (ADC), almost no expression of decorin was observed, in contrast to squamous cell carcinoma (SCC) (P=0.006).

CONCLUSION

Decreased levels of decorin in NSCLC tissue samples, particularly ADC cases, indicate that decorin could play a role in lung cancer carcinogenesis.