CCN: core regulatory proteins in the microenvironment that affect the metastasis of hepatocellular carcinoma?

Characterisation of mesenchymal stem cells conditioned media obtained at different conditioning times: their effect on glial cells in in vitro scratch model

In this study, the bone marrow mesenchymal stem cells conditioned media (BMMSC-CM) obtained by conditioning for 24(CM24), 48(CM48) and 72(CM72) hours was characterised. In vitro, the impact of BMMSC-CM on the astrocyte migratory response and oligodendrocyte density was evaluated using the scratch model. The proteomic profiles of individual secretomes were analysed by mass spectrometry and the concentrations of four selected neurotrophins (BDNF, NGF, GDNF and VEGF) were determined by ELISA. Our results revealed an increased number of proteins at CM72, many of which are involved in neuroregenerative processes. ELISA documented a gradual increase in the concentration of two neurotrophins (NGF, VEGF), peaking at CM72. In vitro, the different effect of individual BMMSC-CM on astrocyte migration response and oligodendrocyte density was observed, most pronounced with CM72. The outcomes demonstrate that the prolonged conditioning results in increased release of detectable proteins, neurotrophic factors concentration and stronger effect on reparative processes in neural cell cultures.

Ephrin-Eph receptor tyrosine kinases for potential therapeutics against hepatic pathologies

Hepatic fibrosis is the common pathological change that occurs due to increased synthesis and accumulation of extracellular matrix components. Chronic insult from hepatotoxicants leads to liver cirrhosis, which if not reversed timely using appropriate therapeutics, liver transplantation remains the only effective therapy. Often the disease further progresses into hepatic carcinoma. Although there is an increased advancement in understanding the pathological phenotypes of the disease, additional knowledge of the novel molecular signaling mechanisms involved in the disease progression would enable the development of efficacious therapeutics. Ephrin-Eph molecules belong to the largest family of receptor tyrosine kinases (RTKs) which are identified to play a crucial role in cellular migratory functions, during morphological and developmental stages. Additionally, they contribute to the growth of a multicellular organism as well as in pathological conditions like cancer, and diabetes. A wide spectrum of mechanistic studies has been performed on ephrin-Eph RTKs in various hepatic tissues under both normal and diseased conditions revealing their diverse roles in hepatic pathology. This systematic review summarizes the liver-specific ephrin-Eph RTK signaling mechanisms and recognizes them as druggable targets for mitigating hepatic pathology.

Exploring the macromolecules for secretory pathway in cancer disease

Secretory proteins play an important role in the tumor microenvironment and are widely distributed throughout tumor tissues. Tumor cells secrete a protein that mediates communication between tumor cells and stromal cells, thereby controlling tumor growth and affecting the success of cancer treatments in the clinic. The cancer secretome is produced by various secretory pathways and has a wide range of applications in oncoproteomics. Secretory proteins are involved in cancer development and tumor cell migration, and thus serve as biomarkers or effective therapeutic targets for a variety of cancers. Several proteomic strategies have recently been used for the analysis of cancer secretomes in order to gain a better understanding and elaborate interpretation. For instance, the development of exosome proteomics, degradomics, and tumor-host cell interaction provide clear information regarding the mechanism of cancer pathobiology. In this chapter, we emphasize the recent advances in secretory protein and the challenges in the field of secretome analysis and their clinical applications.

Learning the histone codes with large genomic windows and three-dimensional chromatin interactions using transformer

The quantitative characterization of the transcriptional control by histone modifications has been challenged by many computational studies, but most of them only focus on narrow and linear genomic regions around promoters, leaving a room for improvement. We present Chromoformer, a transformer-based, three-dimensional chromatin conformation-aware deep learning architecture that achieves the state-of-the-art performance in the quantitative deciphering of the histone codes in gene regulation. The core essence of Chromoformer architecture lies in the three variants of attention operation, each specialized to model individual hierarchy of transcriptional regulation involving from core promoters to distal elements in contact with promoters through three-dimensional chromatin interactions. In-depth interpretation of Chromoformer reveals that it adaptively utilizes the long-range dependencies between histone modifications associated with transcription initiation and elongation. We also show that the quantitative kinetics of transcription factories and Polycomb group bodies can be captured by Chromoformer. Together, our study highlights the great advantage of attention-based deep modeling of complex interactions in epigenomes.

Heparin and Heparin-Based Drug Delivery Systems: Pleiotropic Molecular Effects at Multiple Drug Resistance of Osteosarcoma and Immune Cells

One of the main problems of modern health care is the growing number of oncological diseases both in the elderly and young population. Inadequately effective chemotherapy, which remains the main method of cancer control, is largely associated with the emergence of multidrug resistance in tumor cells. The search for new solutions to overcome the resistance of malignant cells to pharmacological agents is being actively pursued. Another serious problem is immunosuppression caused both by the tumor cells themselves and by antitumor drugs. Of great interest in this context is heparin, a biomolecule belonging to the class of glycosaminoglycans and possessing a broad spectrum of biological activity, including immunomodulatory and antitumor properties. In the context of the rapid development of the new field of “osteoimmunology,” which focuses on the collaboration of bone and immune cells, heparin and delivery systems based on it may be of intriguing importance for the oncotherapy of malignant bone tumors. Osteosarcoma is a rare but highly aggressive, chemoresistant malignant tumor that affects young adults and is characterized by constant recurrence and metastasis. This review describes the direct and immune-mediated regulatory effects of heparin and drug delivery systems based on it on the molecular mechanisms of (multiple) drug resistance in (onco) pathological conditions of bone tissue, especially osteosarcoma.

AXL and MET in Hepatocellular Carcinoma: A Systematic Literature Review

BACKGROUND

Multikinase inhibitors (MKIs) have been shown to improve survival in patients with hepatocellular carcinoma (HCC) compared with placebo. Distinct from other MKIs, cabozantinib has inhibitory activity for both AXL and MET. This review considers the literature elucidating the role of AXL and MET in HCC progression, treatment resistance, and immunomodulation. A systematic search of the PubMed database was conducted on November 16, 2020, and identified a total of 174 search results. A further 36 potentially relevant articles were identified based on the authors' knowledge. After initial screening by title/abstract, 159 underwent full-text screening and we identified 69 original research articles reporting empirical data from in vitro or in vivo models of HCC evaluating the effects of manipulating AXL or MET signaling on tumorigenic behavior.

SUMMARY

AXL expression is highly correlated with HCC progression and outcomes and has been reported to be involved in transforming growth factor-β and the regulation of PI3K/AKT, ERK/MAPK, and CCN proteins. MET protein expression is increased in HCC with the highest histological grade and has been reported to be involved in the regulation of PI3K/AKT, PLCγ/DAG/PKC, and MAPK/ERK signaling. Both AXL and MET are key regulators of sorafenib resistance in HCC. In terms of immunomodulation, there are data to indicate that AXL and MET interact with the immune components of the tumor microenvironment and promote tumorigenesis and treatment resistance. In addition, AXL was found to play a potential role in the development of a protumorigenic neutrophil phenotype in HCC. Combined inhibition of MET and programmed cell death protein resulted in additive reduction of HCC cell growth.

KEY MESSAGES

AXL and MET play key roles in HCC progression, treatment resistance, and immunomodulation. Continued development of drugs that target these receptor tyrosine kinases appears likely to represent a useful strategy to improve outcomes for patients with HCC.

Cellular communication network factor 3 in cartilage development and maintenance

Cellular communication network factor (CCN) 3 is one of the classical members of the CCN family, which are characterized by common molecular structures and multiple functionalities. Although this protein was discovered as a gene product overexpressed in a truncated form in nephroblastoma, recent studies have revealed its physiological roles in the development and homeostasis of mammalian species, in addition to its pathological association with a number of diseases. Cartilage is a tissue that creates most of the bony parts and cartilaginous tissues that constitute the human skeleton, in which CCN3 is also differentially produced to exert its molecular missions therein. In this review article, after the summary of the molecular structure and function of CCN3, recent findings on the regulation of ccn3 expression and the roles of CCN3 in endochondral ossification, cartilage development, maintenance and disorders are introduced with an emphasis on the metabolic regulation and function of this matricellular multifunctional molecule.

Dual roles of WISP2 in the progression of hepatocellular carcinoma: implications of the fibroblast infiltration into the tumor microenvironment

The dismal outcome of hepatocellular carcinoma (HCC) patients is attributable to high frequency of metastasis and. Identification of effective biomarkers is a key strategy to inform prognosis and improve survival. Previous studies reported inconsistent roles of WISP2 in carcinogenesis, while the role of WISP2 in HCC progression also remains unclear. In this study, we confirmed that WISP2 was downregulated in HCC tissues, and WISP2 was acting as a protective factor, especially in patients without alcohol intake using multiple online datasets. In addition, we reported that upregulation of WISP2 in HCC was related to inhibition of the malignant phenotype in vitro, but these alterations were not observed in vivo. WISP2 also negatively correlated with tumour purity, and increased infiltration of fibroblasts promoted malignant progression in HCC tissues. The enhanced infiltration ability of fibroblasts was related to upregulated HMGB1 after overexpression of WISP2 in HCC. The findings shed light on the anticancer role of WISP2, and HMGB1 is one of the key factors involved in the inhibition of the efficiency of WISP2 through reducing the tumour purity with fibroblast infiltration.

Selective cytotoxic activity and protective effects of sodium ascorbate against hepatocellular carcinoma through its effect on oxidative stress and apoptosis in vivo and in vitro

Objectives: Hepatocellular carcinoma (HCC) is characterized by elevated in oxidative stress and inflammatory cytokines, which enhance destructive effects of the tumor. Therefore, we conducted this study to investigate the protective effects of sodium ascorbate against thioacetamide-induced HCC in rats through studying its effect on the apoptotic pathway in rats. In addition, in vitro activity of sodium ascorbate was investigated on HepG2 and compared with cisplatin.

Methods: HCC was experimentally induced by injecting rats with 200 mg/kg thioacetamide intraperitoneally twice weekly for 16 weeks. Part of HCC rats was concomitantly treated with 100 mg/kg sodium ascorbate intraperitoneally during the 16-week period. Hepatic tissues were used for the determination of NFκB, Nrf2, TNF-α, caspase-3, caspase-8 and caspase-9.

Results: Sodium ascorbate significantly attenuated HCC-induced reduction in the expression of NrF2 associated with a reduction in concentrations of hydrogen peroxide and superoxide anion. In addition, sodium ascorbate blocked HCC-induced increase in the expression of NFκB and TNF-α. Sodium ascorbate slightly increased the activity of caspase-3, -8 and -9 in vitro but inhibited their activities in vivo.

Conclusion: In spite of the antioxidant and anti-inflammatory activity of sodium ascorbate, it produced selective cytotoxic activity via direct activation of the apoptotic pathway in cancer cells without affecting the apoptotic pathway in normal hepatic cells.

CCN Family Proteins in Cancer: Insight Into Their Structures and Coordination Role in Tumor Microenvironment

The crosstalk between tumor cells and the tumor microenvironment (TME), triggers a variety of critical signaling pathways and promotes the malignant progression of cancer. The success rate of cancer therapy through targeting single molecule of this crosstalk may be extremely low, whereas co-targeting multiple components could be complicated design and likely to have more side effects. The six members of cellular communication network (CCN) family proteins are scaffolding proteins that may govern the TME, and several studies have shown targeted therapy of CCN family proteins may be effective for the treatment of cancer. CCN protein family shares similar structures, and they mutually reinforce and neutralize each other to serve various roles that are tightly regulated in a spatiotemporal manner by the TME. Here, we review the current knowledge on the structures and roles of CCN proteins in different types of cancer. We also analyze CCN mRNA expression, and reasons for its diverse relationship to prognosis in different cancers. In this review, we conclude that the discrepant functions of CCN proteins in different types of cancer are attributed to diverse TME and CCN truncated isoforms, and speculate that targeting CCN proteins to rebalance the TME could be a potent anti-cancer strategy.

SANT, a novel Chinese herbal monomer combination, decreasing tumor growth and angiogenesis via modulating autophagy in heparanase overexpressed triple-negative breast cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Astragalus mongholicus, Solanum nigrum Linn, Lotus plumule, Ligusticum are widely used traditional herbal medicines for cancer treatment in China. They were typical drugs selected from Gubenyiliu II and series of formula (GYII), which were developed on the foundation of YIQIHUOXUEJIEDU theory. In the present study, four active ingredients (Astragaloside IV, α-solanine, neferine, and 2,3,5,6-tetramethylpyrazine) derived from medicines above were applied in combination as SANT.

AIM OF THE STUDY

Triple-negative breast cancer (TNBC) is a serious threat to women's health worldwide. Heparanase (HPSE) is often up-regulated in breast cancer with the properties of facilitating tumorigenesis and influencing the autophagy process in cancer cells. This study aimed at evaluating the anti-tumor potential of SANT in treating HPSE related TNBC both in-vitro and in-vivo.

MATERIALS AND METHODS

In this study, we explored the correlation between HPSE expression and survival of breast cancer patients in databases. We performed MTS, trans-well and wound scratch assays to assess the impact of SANT on cell proliferation and migration. Confocal microscopy observation and western blots were applied to verify the autophagy flux induced by SANT. Mice models were employed to evaluate the efficacy and safety of SANT in-vivo by tumor weights and volumes or serum index, respectively. To analyze the underlying mechanisms of SANT, we conducted human autophagy PCR array and angiogenesis proteome profiler on tumor tissues.

RESULTS

Patients with elevated HPSE expression were associated with a poor outcome in both RFS (P = 1.7e-12) and OS (P = 0.00016). SANT administration significantly inhibited cancer cells' proliferation and migration, enhanced autophagy flux, and slightly reduced the active form of HPSE in-vitro. SANT also suppressed tumor growth and angiogenesis in-vivo. Human autophagy PCR array results indicated that SANT increased the ATG16L1, ATG9B, ATG4D gene expressions while decreased TMEM74 and TNF gene expressions.Angiogenesis proteome profiler results showed SANT reduced protein level of HB-EGF, thrombospondin-2, amphiregulin, leptin, IGFBP-9, EGF, coagulation factor III, and MMP-9 (pro and active form) in tumor, raised the protein expression of serpin E1 and platelet factor 4.

CONCLUSIONS

These findings indicated that herbal compounds SANT may be a promising candidate in anti-cancer drug discovery. It also provides novel strategies for using natural compounds to achieve optimized effect.

Modulating the Crosstalk between the Tumor and Its Microenvironment Using RNA Interference: A Treatment Strategy for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy with one of the highest mortality rates among solid cancers. It develops almost exclusively in the background of chronic liver inflammation, which can be caused by viral hepatitis, chronic alcohol consumption or an unhealthy diet. Chronic inflammation deregulates the innate and adaptive immune responses that contribute to the proliferation, survival and migration of tumor cells. The continuous communication between the tumor and its microenvironment components serves as the overriding force of the tumor against the body's defenses. The importance of this crosstalk between the tumor microenvironment and immune cells in the process of hepatocarcinogenesis has been shown, and therapeutic strategies modulating this communication have improved the outcomes of patients with liver cancer. To target this communication, an RNA interference (RNAi)-based approach can be used, an innovative and promising strategy that can disrupt the crosstalk at the transcriptomic level. Moreover, RNAi offers the advantage of specificity in comparison to the treatments currently used for HCC in clinics. In this review, we will provide the recent data pertaining to the modulation of a tumor and its microenvironment by using RNAi and its potential for therapeutic intervention in HCC.

IQGAP1 promotes anoikis resistance and metastasis through Rac1-dependent ROS accumulation and activation of Src/FAK signalling in hepatocellular carcinoma

BACKGROUND

Hepatitis B virus (HBV) has a crucial role in the progression of hepatocellular carcinoma (HCC). Tumour cells must develop anoikis resistance in order to survive before metastasis. This study aimed to investigate the mechanism of IQGAP1 in HBV-mediated anoikis evasion and metastasis in HCC cells.

METHODS

IQGAP1 expression was detected by immunohistochemistry, real-time PCR and immunoblot analysis. Lentiviral-mediated stable upregulation or knockdown of IGAQP1, immunoprecipitation, etc. were used in function and mechanism study.

RESULTS

IQGAP1 was markedly upregulated in HBV-positive compared with HBV-negative HCC cells and tissues. IQGAP1 was positively correlated to poor prognosis of HBV-associated HCC patients. IQGAP1 overexpression significantly enhanced the anchorage-independent growth and metastasis, whereas IQGAP1-deficient HCC cells are more sensitive to anoikis. Mechanistically, we found that HBV-induced ROS enhanced the association of IQGAP1 and Rac1 that activated Rac1, leading to phosphorylation of Src/FAK pathway. Antioxidants efficiently inhibited IQGAP1-mediated anoikis resistance and metastasis.

CONCLUSIONS

Our study indicated an important mechanism by which upregulated IQGAP1 by HBV promoted anoikis resistance, migration and invasion of HCC cells through Rac1-dependent ROS accumulation and activation of Src/FAK signalling, suggesting IQGAP1 as a prognostic indicator and a novel therapeutic target in HCC patients with HBV infection.

WISP1 Predicts Clinical Prognosis and Is Associated With Tumor Purity, Immunocyte Infiltration, and Macrophage M2 Polarization in Pan-Cancer

Cancer is becoming the leading cause of death and a major public health problem. Although many advanced treatment strategies are currently in use, the general prognosis of cancer patients remains dismal due to the high frequency of recurrence, metastasis. The identification of effective biomarkers is important for predicting survival of cancer patients and improving treatment efficacy. In this study, we comprehensively analyzed WNT1-inducible-signaling pathway protein 1 (WISP1) expression and explored its correlation with prognosis in pan-cancer using tumor IMmune Estimation Resource (TIMER) and Gene Expression Profiling Interactive Analysis 2 (GEPIA2). We also examined correlations between WISP1 and immunocyte infiltration using TIMER. We identified genes co-expressed with WISP1 using the LinkedOmics database and analyzed associated gene ontology using Metascape. Finally, we constructed protein-protein interaction networks and examined correlations between genes co-expressed with WISP1 and immunocyte infiltration in pan-cancer. WISP1 level differed between human pan-cancer tissues and normal tissues, indicating its potential as a prognostic biomarker. WISP1 expression was correlated with tumor purity and immunocyte infiltration, especially monocyte-macrophage trafficking and M2 polarization. Genes co-expressed with WISP1 were mainly associated with extracellular matrix organization, with collagen members COL6A3, COL5A1, and COL8A1 being key genes correlated with macrophage infiltration and M2 polarization in pan-cancer. Conversely, in certain types of cancer with better prognoses, WISP1 was associated with low M2 macrophage infiltration. These results suggest that WISP1 affect clinical prognosis through associations with tumor purity, immune cell infiltration, and macrophage M2 polarization in pan-cancer, with collagen member proteins may serving as effector molecules of WISP1.

Remodeling of hepatic stellate cells orchestrated the stroma-derived oxaliplatin-resistance through CCN3 paracrine in hepatocellular carcinoma

BACKGROUND

Hepatic stellate cells (HSCs) have a key role in fibrogenesis and in the filtrates of the hepatocellular carcinoma (HCC) stroma, in which they are remodeled and play a critical role in HCC progression. However, the precise role of HSCs trending, infiltration and paracrine in orchestrating the stroma-derived oxaliplatin-resistance in HCC is still vague.

METHODS

The chemo-resistant models were established to explore the correlation between HSC cells and the condition of chemoresistance. The HCC clinical samples were collected to confirm this phenomenon. Then, the relationship between secretory CCN3 from oxaliplatin-resistant HCC and the infiltration of HSCs in associated HCC microenvironment was evaluated. Finally, the role and mechanism of HSCs remodeling in the orchestration of oxaliplatin-resistant HCC were explored.

RESULTS

The increased infiltration of HSCs and collagen accumulation were found in the microenvironment of oxaliplatin-resistant HCC. The cDNA profiles of the oxaliplatin-resistant HCC was reanalyzed, and CCN3 was one of the significantly increased genes. In HCC clinical samples, the levels of CCN3 and α-SMA are positively correlated, and high expression of CCN3 and α-SMA are positively associated with malignant phenotype and poor prognosis. Then the enhanced abilities of migration and proliferation of HSCs, and elevation of the cytokines paracrine from HSCs relating to HCC malignancy were proved in vitro and in vivo, and which were related to CCN3-ERK signaling pathway activation.

CONCLUSIONS

HSCs remodeling are positively related to CCN3 paracrine in hepatocellular carcinoma, which orchestrated the stroma-derived resistance to chemotherapy in HCC.

CCN2-MAPK-Id-1 loop feedback amplification is involved in maintaining stemness in oxaliplatin-resistant hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the second leading cause of cancer death worldwide. Chemotherapy is an alternative treatment for advanced HCCs, but chemo-resistance prevents cancer therapies from achieving stable and complete responses. Understanding the underlying mechanisms in chemo-resistance is critical to improve the efficacy of HCC.

Methods

The expression levels of Id-1 and CCN2 were detected in large cohorts of HCCs, and functional analyses of Id-1 and CCN2 were performed both in vitro and in vivo. cDNA microarrays were performed to evaluate the alterations of expression profiling of HCC cells with overexpression of CCN2. Finally, the role of downstream signaling of MAPK/Id-1 signaling pathway in oxaliplatin resistance were also explored.

Results

The increased expression of Id-1 and CCN2 were closely related to oxaliplatin resistance in HCC. Upregulation of CCN2 and Id-1 was independently associated with shorter survival and increased recurrence in HCC patients, and significantly enhanced oxaliplatin resistance and promoted lung metastasis in vivo, whereas knock-down of their expression significantly reversed the chemo-resistance and inhibited HCC cell stemness. cDNA microarrays and PCR revealed that Id-1 and MAPK pathway were the downstream signaling of CCN2. CCN2 significantly enhanced oxaliplatin resistance by activating the MAPK/Id-1 signaling pathway, and Id-1 could upregulate CCN2 in a positive feedback manner.

Conclusions

CCN2/MAPK/Id-1 loop feedback amplification is involved in oxaliplatin resistance, and the combination of oxaliplatin with inhibitor of CCN2 or MAPK signaling could provide a promising approach to ameliorating oxaliplatin resistance in HCC.

Electronic supplementary material

The online version of this article (10.1007/s12072-019-09960-5) contains supplementary material, which is available to authorized users.

Paracrine effects of CCN3 from non-cancerous hepatic cells increase signaling and progression of hepatocellular carcinoma

BACKGROUND

The liver microenvironment plays a key role in the progression and metastasis of hepatocellular carcinoma (HCC). Gene expression profiling of non-cancerous hepatic tissues obtained from patients with metastatic HCC exhibit a unique immune response signature, including upregulation of CCN3. However, the role of CCN3 secreted from non-cancerous hepatic tissues in the progression of HCC remains unclear.

METHODS

Using tissue microarrays, we examined CCN3 in non-cancerous hepatic tissues of patients with HCC and correlated expression with clinical and pathological features. In addition, CCN3 localization and mechanisms of HCC progression were investigated in tissues and cell lines. Finally, correlations between CCN3 and cirrhosis were explored in patients.

RESULTS

CCN3 was primarily localized to hepatic cells of non-cancerous hepatic tissues and was associated with vascular invasion and poor prognosis in patients with HCC. CCN3 expression in non-cancerous hepatic tissues also correlated with the degree of liver fibrosis. Compared with conditioned media from wild-type LO2 cells, conditioned media from hepatic cell line LO2 activated by LX2 (aLO2-CM) induced CCN3 expression and HCC cell proliferation and metastasis. Further, aLO2-CM activated MAPK signaling and epithelial-mesenchymal transition in HCC cells. Finally, CCN3 was inversely related to cirrhosis in the prognosis of HCC and negatively regulated hepatic stellate cells (HSCs) in vitro with downregulation of α-SMA, TGF-β, and collagens.

CONCLUSIONS

CCN3 was secreted from hepatic cells activated by HSCs and increased MAPK signaling, EMT, proliferation and metastasis of HCC cells. CCN3 was also inversely related to cirrhosis, regulating HSCs through a negative feedback loop.

Effects of resveratrol and its analogue pterostilbene, on NOV/CCN3 adipokine in adipose tissue from rats fed a high-fat high-sucrose diet

Nephroblastoma overexpressed protein, also called NOV/CCN3, is an adipokine which is present in various tissues and recently linked to obesity. The objective of the study was to determine the effect of resveratrol and pterostilbene on NOV/CCN3 in adipose tissue from rats fed an obesogenic diet. Thirty-six male Wistar rats were split into four groups (n = 9): fed a standard diet (CC), high-fat high-sucrose (HFS) diet supplemented with resveratrol (RSV; 30 mg/kg/day) or with pterostilbene (PT; 30 mg/kg/day), or without phenolic supplementation (HFS). Rats were sacrificed after 6 weeks of treatment, and adipose tissue (white and brown) from different anatomical locations were dissected. Then, Nov/ccn3 gene and protein expression and the adipogenic genes, Ucp-1 and Pgc-1a, expressions were studied. Increased weight of white adipose tissues was found in rats fed the HFS diet. Whereas resveratrol-treated rats showed reduced internal and total adipose tissue weights, pterostilbene-treated rats showed reduced subcutaneous, internal and total adipose depots. Nov/ccn3 gene expression decreased in epididymal and interscapular brown depot in rats fed HFS diet when compared with the control group. Regarding the phenolic compounds, resveratrol prompted a Nov/ccn3 gene expression increase in epididymal fat tissue, whereas pterostilbene reduced its protein expression compared with the obese group. However, these phenolic compounds did not affect NOV/CCN3 expression in brown depot. NOV/CCN3 seems to be involved in weight changes in epididymal adipose tissue under obesogenic feeding, but not in subcutaneous, acting as a protective mechanism counteracting the fattening effect of the diet. To our knowledge, this is the first study analyzing whether NOV/CCN3 is involved in the anti-obesity effect of resveratrol and pterostilbene. Our results suggest that this is not the case.

Melittin Inhibits Hypoxia-Induced Vasculogenic Mimicry Formation and Epithelial-Mesenchymal Transition through Suppression of HIF-1α/Akt Pathway in Liver Cancer

In this study, we investigated whether melittin could suppress hypoxia-induced vasculogenic mimicry (VM) formation in liver cancer and explored the underlying mechanisms. Melittin significantly inhibited the proliferation of liver cancer cells with or without CoCl₂ presence. Melittin also significantly inhibited CoCl₂-induced migration, invasion, and VM formation of liver cancer cells. CoCl₂ treatment suppressed the expression of E-cadherin and elevated the expression of N-cadherin and Vimentin. Melittin reversed the changes in the protein and mRNA levels of these epithelial-mesenchymal transition (EMT) markers. CoCl₂-induced accumulation of HIF-1α increased the level of phosphorylated Akt and upregulated the expression of VEGF and MMP-2/9. Melittin decreased the HIF-1α level and thereby suppressed the levels of p-Akt, VEGF, and MMP-2/9. In addition, the inhibitor of PI3K/Akt also suppressed CoCl₂-induced EMT and liver cancer cells migration, and the activator of Akt, SC-79, partly blocked the effect of melittin on CoCl₂-induced EMT and liver cancer cells migration. In the xenograft tumor model in nude mice, melittin treatment significantly suppressed the tumor growth, VM formation, and HIF-1α expression in the tumor. In conclusion, this study indicates melittin may inhibit hypoxia-induced VM formation and EMT in liver cancer through inhibiting HIF-1α/Akt pathway.

The role of CCN4/WISP-1 in the cancerous phenotype

CCN proteins are secreted into the extracellular environment where they interact with both components of the extracellular matrix and with cell surface receptors to regulate cellular function. Through these interactions, CCNs act as extracellular ligands to activate intracellular signal transduction pathways. CCN4/WISP-1, like other CCNs, plays multiple physiologic roles in development and also participates in pathogenesis. CCN4 is of particular interest with respect to cancer, showing promise as a biomarker or prognostic factor as well as a potential therapeutic target. This review focuses on recent work addressing the role of CCN4 in cancer. While CCN4 has been identified as an oncogene in a number of cancers, where it enhances cell migration and promoting epithelial-mesenchymal transition, there are other cancers where CCN4 appears to play an inhibitory role. The mechanisms underlying these differences in cellular response have not yet been delineated, but are an active area of investigation. The expression and activities of CCN4 splice variants are likewise an emerging area for study. CCN4 acts as an autocrine factor that regulates the cancer cells from which it is secreted. However, CCN4 is also a paracrine factor that is secreted by stromal fibroblasts, and can affect the function of vascular endothelial cells. In summary, current evidence is abundant in regard to establishing potential roles for CCN4 in oncogenesis, but much remains to be learned about the functions of this fascinating protein as both an autocrine and paracrine regulator in the tumor microenvironment.

The Chinese Medicine, Jiedu Recipe, Inhibits the Epithelial Mesenchymal Transition of Hepatocellular Carcinoma via the Regulation of Smad2/3 Dependent and Independent Pathways

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. In China, traditional Chinese herb medicine has been widely used in the treatment of HCC. Jiedu Recipe (JR) is a common used prescription which has shown good results against HCC. However, the exact mechanisms of JR are still unknown. Therefore, we investigated the efficacy of JR on HCC in the current study. JR inhibited the cell viability of both SMMC-7721 and Huh7 cells in both time- and dose-dependent manners. Transwell assay revealed that JR decreased the number of migrated cells of SMMC-7721 cells. JR treatment increased the E-cadherin expression level and decreased the levels of p-Smad2/3 and Smad2/3. Further study showed that JR reversed the effect of TGFβ1 on the expression of E-cadherin, vimentin, N-cadherin, and MMP2/9. JR also significantly inhibited TGFβ1-induced migration and invasion of SMMC-7721 and Huh7 cells determined by wound healing assay and transwell assay. TGFβ1 treatment increased the phosphorylation of Smad2/3, p38 MAPK, JNK, ERK1/2, and Akt in SMMC-7721 cells and pretreatment with JR blocked TGFβ1-induced activation of Smad2/3 and Akt and MAPKs. In conclusion, JR inhibits liver cancer cells migration and invasion through epithelial mesenchymal transition (EMT) inhibition via Smad2/3 dependent and independent pathways, suggesting it is an effective therapeutic strategy against HCC metastasis.

Tumor-associated macrophage-derived cytokines enhance cancer stem-like characteristics through epithelial-mesenchymal transition

Cancer stem cells are a small population of cells with the potential for self-renewal and multi-directional differentiation and are an important source of cancer initiation, treatment resistance, and recurrence. Epithelial-mesenchymal transition (EMT) is a process in which epithelial cells lose their epithelial phenotype and convert to mesenchymal cells. Recent studies have shown that cancer cells undergoing EMT can become stem-like cells. Many kinds of tumors are associated with chronic inflammation, which plays a role in tumor progression. Among the various immune cells mediating chronic inflammation, macrophages account for ~30%-50% of the tumor mass. Macrophages are highly infiltrative in the tumor microenvironment and secrete a series of inflammatory factors and cytokines, such as transforming growth factor (TGF)-β, IL-6, IL-10, and tumor necrosis factor (TNF)-α, which promote EMT and enhance the stemness of cancer cells. This review summarizes and discusses recent research findings on some specific mechanisms of tumor-associated macrophage-derived cytokines in EMT and cancer stemness transition, which are emerging targets of cancer treatment.

Up-regulation of CTD-2547G23.4 in hepatocellular carcinoma tissues and its prospective molecular regulatory mechanism: a novel qRT-PCR and bioinformatics analysis study

Background

Dysregulated expression of long non-coding RNAs (lncRNAs) has been reported in the pathogenesis and progression of multiple cancers, including hepatocellular carcinoma (HCC). LncRNA CTD-2547G23.4 is a novel lncRNA, and its role in HCC is still unknown. Here, we aimed to clarify the expression pattern and clinical value of CTD-2547G23.4 and to investigate the prospective regulatory mechanism via bioinformatics analysis in HCC.

Methods

To identify differentially expressed lncRNAs in HCC, we downloaded RNA-Seq data for HCC and adjacent non-tumour tissues via The Cancer Genome Atlas (TCGA). CTD-2547G23.4 was selected by using the R language and receiver operating characteristic curve analysis. Furthermore, we validated the differential expression of CTD-2547G23.4 via Gene Expression Omnibus (GEO), ArrayExpress, Oncomine databases and quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between the CTD-2547G23.4 level and clinic pathological parameters was also assessed. To further probe the role of CTD-2547G23.4 in HCC cell cycle, lentivirus-mediated small interfering RNA was applied to silence CTD-2547G23.4 expression in Huh-7 cell line. In addition, the related genes of CTD-2547G23.4 gathered from The Atlas of Noncoding RNAs in Cancer (TANRIC) database and Multi Experiment Matrix (MEM) were assessed with Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes, Protein Analysis Through Evolutionary Relationships and protein–protein interaction (PPI) networks.

Results

CTD-2547G23.4 expression was remarkably higher in 370 HCC tissue samples than that in adjacent non-tumour liver tissues (48.762 ± 27.270 vs. 14.511 ± 8.341, P < 0.001) from TCGA dataset. The relative expression level of CTD-2547G23.4 in HCC was consistently higher than that in adjacent non-cancerous tissues (2.464 ± 0.833 vs. 1.813 ± 0.784, P = 0.001) as assessed by real time RT-qPCR. The area under the curve of the summary receiver operating characteristic curve was 0.8720 based on TCGA, qRT-PCR and GEO data. Further analysis indicated that the increased expression levels of CTD-2547G23.4 were associated with the neoplasm histologic grade and vascular tumour cell type. The expression of CTD-2547G23.4 was significantly downregulated in CTD-2547G23.4 knockdown cells. Moreover, cell cycle analysis revealed that CTD-2547G23.4 depletion in Huh-7 cell line led to S phase arrest. Furthermore, 314 related genes identified by TANRIC and MEM databases were processed with a pathway analysis. The bioinformatics analysis indicated that CTD-2547G23.4 might play a key role in the progress of HCC through four hub genes, SRC, CREBBP, ADCY8 and PPARA.

Conclusions

Collectively, we put forward the hypothesis that the novel lncRNA CTD-2547G23.4 may act as an exceptional clinical index and promote the HCC tumourigenesis and progression via various related genes.

Electronic supplementary material

The online version of this article (10.1186/s12935-018-0566-3) contains supplementary material, which is available to authorized users.

Expression of the Long Intergenic Non-Protein Coding RNA 665 (LINC00665) Gene and the Cell Cycle in Hepatocellular Carcinoma Using The Cancer Genome Atlas, the Gene Expression Omnibus, and Quantitative Real-Time Polymerase Chain Reaction

Background

Long non-coding RNAs (lncRNAs) have a role in physiological and pathological processes, including cancer. The aim of this study was to investigate the expression of the long intergenic non-protein coding RNA 665 (LINC00665) gene and the cell cycle in hepatocellular carcinoma (HCC) using database analysis including The Cancer Genome Atlas (TCGA), the Gene Expression Omnibus (GEO), and quantitative real-time polymerase chain reaction (qPCR).

Material/Methods

Expression levels of LINC00665 were compared between human tissue samples of HCC and adjacent normal liver, clinicopathological correlations were made using TCGA and the GEO, and qPCR was performed to validate the findings. Other public databases were searched for other genes associated with LINC00665 expression, including The Atlas of Noncoding RNAs in Cancer (TANRIC), the Multi Experiment Matrix (MEM), Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein-protein interaction (PPI) networks.

Results

Overexpression of LINC00665 in patients with HCC was significantly associated with gender, tumor grade, stage, and tumor cell type. Overexpression of LINC00665 in patients with HCC was significantly associated with overall survival (OS) (HR=1.47795%; CI: 1.046–2.086). Bioinformatics analysis identified 469 related genes and further analysis supported a hypothesis that LINC00665 regulates pathways in the cell cycle to facilitate the development and progression of HCC through ten identified core genes: CDK1, BUB1B, BUB1, PLK1, CCNB2, CCNB1, CDC20, ESPL1, MAD2L1, and CCNA2.

Conclusions

Overexpression of the lncRNA, LINC00665 may be involved in the regulation of cell cycle pathways in HCC through ten identified hub genes.

Predictive value of microRNA-143 in evaluating the prognosis of patients with hepatocellular carcinoma

OBJECTIVE

The study aims to evaluate the predictive value of microRNA-143 (miR-143) for the prognosis of patients with hepatocellular carcinoma (HCC).

METHODS

Between October 2010 and October 2012, 131 HCC patients were selected as a case group; meanwhile, 122 healthy controls were enrolled as a control group. The miR-143 expression in serum was detected by quantitative real-time polymerase chain reaction (qRT-PCR). These HCC patients were divided into the high miR-143 expression group and the low miR-143 expression group based on the threshold of receiver operating characteristic (ROC) curve. Kaplan-Meier method was applied to analyze the prognosis of HCC patients.

RESULTS

MiR-143 exhibited decreased expression in the case group significantly compared to the control group. The areas under the ROC curve (AUC), sensitivity value and specificity value of the miR-143 expression for the diagnosis of HCC were 0.831, 80.30% and 82.40%, respectively. The miR-143 expression was negatively correlated with vascular invasion, TNM staging, tumor recurrence, metastasis and survival of HCC patients.

CONCLUSIONS

Our study provides evidence that miR-143 may be negatively correlated with the prognosis of HCC and provides a promising strategy for HCC treatment and prognosis improvement.

Reduced NOV expression correlates with disease progression in colorectal cancer and is associated with survival, invasion and chemoresistance of cancer cells

Aberrant expression of nephroblastoma overexpressed (NOV) has been evident in certain malignancies. In the current study, we aim to investigate the role played by NOV in colorectal cancer (CRC). NOV expression was determined in a cohort of 359 CRC tissues and 174 normal colorectal tissues. Its impact on CRC cells was investigated using in vitro NOV knockdown and overexpression models. NOV transcripts were reduced in the CRC tumours compared with the paired adjacent normal colorectal tissues (p < 0.01) and was associated with distant metastases. NOV knockdown resulted in increased cell proliferation and invasion of RKO cells, whilst an opposite effect was seen in the HT115 NOV over expressing cells. A positive association between Caspase-3/-8 and NOV was seen in NOV knockdown and overexpression cell lines which contributed to the survival of serum deprived CRC cells. Further investigation showed that NOV regulated proliferation, survival and invasion through the JNK pathway. NOV knockdown in RKO cells reduced the responsiveness to 5-Fluorouracil treatment, whilst overexpression in HT115 cells exhibited a contrasting effect. Taken together, NOV is reduced in CRC tumours and this is associated with disease progression. NOV inhibits the proliferation and invasion of CRC cells in vitro. Inhibition of proliferation is mediated by a regulation of Caspase-3/-8, via the JNK pathway, which has potential for predicting and preventing chemoresistance.

Matricellular protein CCN1 mediates doxorubicin-induced cardiomyopathy in mice

Doxorubicin (DOX) is an effective chemotherapeutic agent however its clinical use is limited by its cumulative cardiotoxicity. Matricellular protein CCN1 mediates work-overload-induced cardiac injury. We aimed to assess the role of CCN1 in DOX-associated cardiomyopathy. Here we discovered CCN1 expression in the myocardium 1 day after DOX treatment (15 mg/kg; i.p.) in mice. Whereas CCN1 synergizes with Fas ligand (FasL) to induce cardiomyocyte apoptosis, we found that FasL was also induced by DOX in the heart. To assess the function of CCN1 in vivo, knockin mice (Ccn1^dm/dm) expressing an β₆β₁-binding defective CCN1 mutant were treated with a single dose of DOX (15 mg/kg; i.p.). Compared with wild-type mice, Ccn1^dm/dm mice were resistant to DOX-induced cardiac injury and dysfunction 14 days after injection. Using rat cardiomyoblast H9c2 cells, we demonstrated that DOX induced reactive oxygen species accumulation to upregulate CCN1 and FasL expression. CCN1 mediated DOX cardiotoxicity by engaging integrin β₆β₁ to promote p38 mitogen-activated protein kinase activation and the release of mitochondrial Smac and HtrA2 to cytosol, thereby counteracting the inhibition of XIAP and facilitating apoptosis. In summary, CCN1 critically mediates DOX-induced cardiotoxicity. Disrupting CCN1/β₆β₁ engagement abolishes DOX-associated cardiomyopathy in mice.

CCN3 is a therapeutic target relating enhanced stemness and coagulation in hepatocellular carcinoma

The general prognosis of patients with hepatocellular carcinoma (HCC) remains extremely dismal, due to the high frequency of metastasis. Since 2003, our research group has explored the gene expression profiles of metastasized HCC tissue samples and identified a significant upregulation of CCN3. However, the role and precise pathological function of CCN3 remains elusive. We showed that CCN3 is associated with the poor prognosis of patients with HCC, the malignant phenotype of HCC, and vascular thrombosis. We further evaluated the negative roles of CCN3 in vitro and in vivo, and identified osteopontin (OPN), and coagulation factors tissue factor (TF) and thrombin as the leading genes downstream of CCN3, that are positively associated with HCC cell stemness. We demonstrated that overexpressed CCN3 in HCC cells leads to enhanced survival and increased number of pulmonary metastases in vivo. The elevated levels of OPN and TF were associated with signal activation of nuclear factor κB (NFκB) and extracellular signal-regulated kinases (ERK). Our findings suggest CCN3 is a potential therapeutic target that would affect the upregulation of OPN and coagulation factors, which would lead to an enhanced stemness and blood coagulation microenvironment in HCC tissue.

Maintenance of stemness is associated with the interation of LRP6 and heparin-binding protein CCN2 autocrined by hepatocellular carcinoma

Background

The overall response rate of hepatocellular carcinoma (HCC) to chemotherapy is poor. In our previous study, oxaliplatin-resistant HCC is found to exhibit an enhanced stemness, and increased levels of CCN2 and LRP6, while the role of CCN2 and LRP6 in the prognosis of HCC patients, and the interaction regulation mechanism between CCN2 and LRP6 are still unclear.

Methods

The expression levels of CCN2 and LRP6 were detected in large cohorts of HCCs, and functional analyses of CCN2 and LRP6 were performed both in vitro and in vivo. The roles of cell surface heparin sulfate proteoglycans (HSPGs) in the mutual regulatory between CCN2 and LRP6 were verified in HCC, and the interventions of low molecular weight heparin sodium (LMWH) were explored.

Results

CCN2 and LRP6 were overexpressed in HCCs, and the CCN2 and LRP6 levels were positively associated with the malignant phenotypes and poor prognosis of HCCs. LRP6 could significantly upregulate the expression of CCN2. Meanwhile, CCN2 was able to enhance malignant phenotype of HCC cells in a dose-dependent manner through binding with LRP6; and knock-down of LRP6 expression, perturbation of HSPGs, co-incubation of CCN2 with LMWH could significantly block the adhesion of CCN2 to LRP6. LMWH enhanced the therapeutic effect of oxaliplatin on HCC with a high CCN2 expression.

Conclusions

 CCN2 plays a promoting role in HCC progression through activating LRP6 in a HSPGs-dependent manner. Heparin in combination with chemotherapy has a synergic effect and could be a treatment choice for HCCs with a high CCN2 expression. 

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-017-0576-3) contains supplementary material, which is available to authorized users.

The essential role of MTDH in the progression of HCC: a study with immunohistochemistry, TCGA, meta-analysis and in vitro investigation

Recent studies found that metadherin (MTDH) played an essential role in hepatocellular carcinoma (HCC). Nevertheless, the exact function of MTDH in the pathogenesis of HCC was unclarified. In the present study, we aimed to investigate the clinical significance of MTDH in HCC and its effect on HCC cells. Immunohistochemistry (IHC) was performed to detect MTDH expression in HCC tissues. Data from The Cancer Genome Atlas (TCGA) and ONCOMINE was obtained to examine MTDH expression in HCC and its clinical significance. Meta-analysis was conducted to assess the correlation between MTDH expression and both the prognosis (Overall Survival (OS) or Disease-free Survival (DFS)) and clinicopathological features of HCC via STATA 12.0. In vitro experiments were performed to investigate the role of MTDH in cell growth, caspase-3/7 activity and apoptosis in HCC cells. The MTDH staining was remarkably stronger in HCC tissues than in non-cancer tissues from IHC, TCGA and ONCOMINE data. Moreover, MTDH-positive expression was significantly correlated with pathological grade, distant metastasis and hepatitis B virus (HBV) infection by IHC. For meta-analysis, MTDH expression was indicative of poor OS without heterogeneity in HCC patients. Additionally, MTDH expression was correlated with high-grade histological differentiation, non-vascular invasion and metastasis in HCC. In vitro experiments revealed that MTDH could the inhibit cell growth and activate caspase-3/7 activity and apoptosis in the four HCC cell lines. In conclusion, MTDH expression may serve as a novel targeting strategy for HCC due to its clinical significance and oncogenic function in HCC cells.

Overexpression of sulfatase-1 in murine hepatocarcinoma Hca-F cell line downregulates mesothelin and leads to reduction in lymphatic metastasis, both in vitro and in vivo

Lymphatic vessels function as transport channels for tumor cells to metastasize from the primary site into the lymph nodes. In this experiment we evaluated the effect of Sulfatase-1 (Sulf-1) on metastasis by upregulating it in murine hepatocarcinoma cell line Hca-F with high lymph node metastatic rate of >75%. The study in vitro showed that upregulation of Sulf-1 in Hca-F cells significantly reduced cell proliferation, migration and invasion (p<0.05). Also, the forced expression of Sulf-1 downregulated Mesothelin (Msln) at both the protein and mRNA levels. The experiment in vivo further showed that up-regulation of Sulf-1 with the attendant downregulation of mesothelin delayed tumor growth and decreased lymph node metastasis. In conclusion, our findings show that Sulf-1 is an important tumor suppressor gene in hepatocellular carcinoma (HCC), and its overexpression downregulates Msln and results in a decrease in HCC cell proliferation, migration, invasion, and lymphatic metastasis. This functional relationship between Sulf-1 and Msln could be exploited for the development of a novel liver cancer therapy.

Members of the Cyr61/CTGF/NOV Protein Family: Emerging Players in Hepatic Progenitor Cell Activation and Intrahepatic Cholangiocarcinoma

Hepatic stem/progenitor cells (HPC) reside quiescently in normal biliary trees and are activated in the form of ductular reactions during severe liver damage when the replicative ability of hepatocytes is inhibited. HPC niches are full of profibrotic stimuli favoring scarring and hepatocarcinogenesis. The Cyr61/CTGF/NOV (CCN) protein family consists of six members, CCN1/CYR61, CCN2/CTGF, CCN3/NOV, CCN4/WISP1, CCN5/WISP2, and CCN6/WISP3, which function as extracellular signaling modulators to mediate cell-matrix interaction during angiogenesis, wound healing, fibrosis, and tumorigenesis. This study investigated expression patterns of CCN proteins in HPC and cholangiocarcinoma (CCA). Mouse HPC were induced by the biliary toxin 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC). Differential expression patterns of CCN proteins were found in HPC from DDC damaged mice and in human CCA tumors. In addition, we utilized reporter mice that carried Ccn2/Ctgf promoter driven GFP and detected strong Ccn2/Ctgf expression in epithelial cell adhesion molecule (EpCAM)⁺ HPC under normal conditions and in DDC-induced liver damage. Abundant CCN2/CTGF protein was also found in cytokeratin 19 (CK19)⁺ human HPC that were surrounded by α-smooth muscle actin (α-SMA)⁺ myofibroblast cells in intrahepatic CCA tumors. These results suggest that CCN proteins, particularly CCN2/CTGF, function in HPC activation and CCA development.

Differential expression of CCN family members CYR611, CTGF and NOV in gastric cancer and their association with disease progression

CCN is an acronym for cysteine-rich protein 61 (CYR61), connective tissue growth factor (CTGF) and nephroblastoma overexpressed (NOV). Aberrations of certain CCN members including CYR61, CTGF, Wnt1-inducible signalling pathway protein (WISP)-1 and -3 have been reported in gastric cancer. The present study aimed to examine the clinical relevance of NOV along with CYR61 and CTGF in gastric cancer by analysing their transcript levels. CYR61, CTGF and NOV transcript expression in 324 gastric cancer samples with paired adjacent normal gastric tissues were determined using real-time quantitative PCR and the results were statistically analysed against patient clinicopathological data using SPSS software. NOV mRNA levels in gastric cancer tissues were significantly elevated when compared with levels in their paired adjacent non-cancerous tissues. Local advanced tumours with invasive expansion (T3 and T4) expressed higher levels of NOV (p=0.013) compared with the less invasive tumours (T1 and T2). CYR61 transcript levels were also significantly increased in gastric cancers compared with levels in the adjacent non-cancerous tissues. Kaplan-Meier survival curves revealed that patients with CYR61-low transcript levels had longer overall survival (OS) (p=0.018) and disease-free survival (DFS) (p=0.015). NOV overexpression promoted the in vitro proliferation of AGS cells while the knockdown resulted in a reduced proliferation of HGC27 cells. A similar effect was observed for the invasion of these two gastric cancer cell lines. NOV expression was increased in gastric cancer which was associated with local invasion and distant metastases. Taken together, the expression of NOV and CYR61 was increased in gastric cancer. The elevated expression of CYR61 was associated with poorer survival. NOV promoted proliferation and invasion of gastric cancer cells. Further investigations may highlight their predictive and therapeutic potential in gastric cancer.

CCN family of proteins: critical modulators of the tumor cell microenvironment

The CCN family of proteins consisting of CCN1 (Cyr61), CCN2 (CTGF), CCN3 (NOV), CCN4 (WISP-1), CCN5 (WISP-2) and CCN6 (WISP-3) are considered matricellular proteins operating essentially in the extracellular microenvironment between cells. Evidence has also been gradually building since their first discovery of additional intracellular roles although the major activity is triggered at the cell membrane. The proteins consist of 4 motifs, a signal peptide (for secretion} followed consecutively by the IGFBP, VWC, TSP1 and CT (C-terminal cysteine knot domain) motifs, which signify their potential binding partners and functional connections to a variety of key regulators of physiological processes. With respect to cancer it is now clear that, whereas certain members can facilitate tumor behavior and progression, others can competitively counter the process. It is therefore clear that the net outcome of biological interactions in the matrix and what gets signaled or inhibited can be a function of the interplay of these CCN 1-6 proteins. Because the CCN proteins further interact with other key proteins, like growth factors in the matrix, the balance is not only important but can vary dynamically with the physiological states of tumor cells and the surrounding normal cells. The tumor niche with its many cell players has surfaced as a critical determinant of tumor behavior, invasiveness, and metastasis. It is in this context that CCN proteins should be investigated with the potential of being recognized and validated for future therapeutic approaches.