CCAAT enhancer binding protein-beta regulates matrix metalloproteinase-1 expression in interleukin-1beta-stimulated A549 lung carcinoma cells

Methamphetamine induces thoracic aortic aneurysm/dissection through C/EBPβ

AIMS

Thoracic aortic aneurysm/dissection (TAAD) is a life-threatening disease with diverse clinical manifestations. Although the association between methamphetamine (METH) and TAAD is frequently observed, the causal relationship between METH abuse and aortic aneurysm/dissection has not been established. This study was designed to determine if METH causes aortic aneurysm/dissection and delineate the underlying mechanism.

METHODS AND RESULTS

A new TAAD model was developed by exposing METH to SD rats pre-treated with lysyl oxidase inhibitor β-aminopropionitrile (BAPN). Combination of METH and BAPN caused thoracic aortic aneurysm/dissection in 60% of rats. BAPN+METH significantly increased the expression and activities of both matrix metalloproteinase MMP2 and MMP9, consistent with the severe elastin breakage and dissection. Mechanistically, METH increased CCAAT-enhancer binding protein β (C/EBPβ) expression by enhancing mothers against decapentaplegic homolog 3 (Smad3) and extracellular regulated protein kinase (ERK1/2) signaling. METH also promoted C/EBPβ binding to MMP2 and MMP9 promoters. Blocking C/EBPβ significantly attenuated METH+BAPN-induced TAAD and MMP2/MMP9 expression. Moreover, BAPN+METH promoted aortic medial smooth muscle cell (SMC) apoptosis through C/EBPβ-mediated IGFBP5/p53/PUMA signaling pathways. More importantly, the expression of C/EBPβ, MMP2/MMP9, and apoptosis-promoting proteins was increased in the aorta of human patients with thoracic aortic dissection, suggesting that the mechanisms identified in animal study could be relevant to human disease.

CONCLUSIONS

Our study demonstrated that METH exposure has a casual effect on TAAD. C/EBPβ mediates METH-introduced TAAD formation by causing elastin breakage, medial cell loss and degeneration. Therefore, C/EBPβ may be a potential factor for TAAD clinical diagnosis or treatment.

Implications of COVID-19 to Stroke Medicine: An Epidemiological and Pathophysiological Perspective

The neurological complications of Coronavirus 2019 (COVID-19) including stroke have been documented in the recent literature. COVID-19-related inflammation is suggested to contribute to both a hypercoagulable state and haemorrhagic transformation, including in younger individuals. COVID-19 is associated with a heightened risk of ischaemic stroke. Haemorrhagic stroke in COVID-19 patients is associated with increased morbidity and mortality. Cerebral venous sinus thrombosis (CVST) accounts for <1% of stroke cases in the general population but has come to heightened public attention due to the increased risk associated with adenoviral COVID-19 vaccines. However, recent evidence suggests the prevalence of stroke is less in vaccinated individuals than in unvaccinated COVID-19 patients. This review evaluates the current evidence of COVID-19-related ischaemic and haemorrhagic stroke, with a focus on current epidemiology and inflammatory-linked pathophysiology in the field of vascular neurology and stroke medicine.

Integrating LCM-Based Spatio-Temporal Transcriptomics Uncovers Conceptus and Endometrial Luminal Epithelium Communication that Coordinates the Conceptus Attachment in Pigs

Attachment of conceptus to the endometrial luminal epithelium (LE) is a critical event for early placentation in Eutheria. Since the attachment occurs at a particular site within the uterus, a coordinated communication between three spatially distinct compartments (conceptus and endometrial LE from two anatomical regions of the uterus to which conceptus attaches and does not attach) is essential but remains to be fully characterized. Using the laser capture microdissection (LCM) technique, we firstly developed an approach that can allow us to pair the pig conceptus sample with its nearby endometrial epithelium sample without losing the native spatial information. Then, a comprehensive spatio-temporal transcriptomic profile without losing the original conceptus-endometrium coordinates was constructed. The analysis shows that an apparent difference in transcriptional responses to the conceptus exists between the endometrial LE from the two anatomically distinct regions in the uterus. In addition, we identified the communication pathways that link the conceptus and endometrial LE and found that these pathways have important roles in conceptus attachment. Furthermore, a number of genes whose expression is spatially restricted in the two different anatomical regions within the uterus were characterized for the first time and two of them (SULT2A1 and MEP1B) may cooperatively contribute to establish conceptus attachment in pigs. The results from our study have implications in understanding of conceptus/embryo attachment in pigs and other large polytocous species.

C/EBPβ promotes the viability of human bladder cancer cell by contributing to the transcription of bladder cancer specific lncRNA UCA1

Urothelial Carcinoma Antigen 1 (UCA1) is a cell and tissue specific long non-coding RNA (lncRNA) associated with the tumorigenesis and invasion of bladder cancer. However, the mechanism driving the over-transcription of UCA1 in bladder cancer cells remains unclear. It has been reported that C/EBPβ has a significant role of regulation in tumorigenesis. Here we report that the expression of UCA1 was dramatically inhibited in 5637 cells with C/EBPβ down-regulation. Additionally, the function tests indicated that C/EBPβ could promote 5637 cells growth and colony formation by inducing the expression level of UCA1. These data suggest that C/EBPβ was involved in transcriptional regulation of UCA1 and contributed substantially to its high expression and proliferation promoting in bladder cancer cells.

C/EBPβ deletion in oncogenic Ras skin tumors is a synthetic lethal event

Therapeutic targeting of specific genetic changes in cancer has proven to be an effective therapy and the concept of synthetic lethality has emerged. CCAAT/enhancer-binding protein-β (C/EBPβ), a basic leucine zipper transcription factor, has important roles in cellular processes including differentiation, inflammation, survival, and energy metabolism. Using a genetically engineered mouse model, we report that the deletion C/EBPβ in pre-existing oncogenic Ha-Ras mouse skin tumors in vivo resulted in rapid tumor regression. Regressing tumors exhibited elevated levels of apoptosis and p53 protein/activity, while adjacent C/EBPβ-deleted skin did not. These results indicate that the deletion of C/EBPβ de-represses p53 in oncogenic Ras tumors but not in normal wild-type Ras keratinocytes, and that C/EBPβ is essential for survival of oncogenic Ras tumors. Co-deletion of C/EBPβ and p53 in oncogenic Ras tumors showed p53 is required for tumor regression and elevated apoptosis. In tumors, loss of a pathway that confers adaptability to a stress phenotype of cancer/tumorigenesis, such as DNA damage, could result in selective tumor cell killing. Our results show that oncogenic Ras tumors display a significant DNA damage/replicative stress phenotype and these tumors have acquired a dependence on C/EBPβ for their survival. RNAseq data analysis of regressing tumors deleted of C/EBPβ indicates a novel interface between p53, type-1 interferon response, and death receptor pathways, which function in concert to produce activation of extrinsic apoptosis pathways. In summary, the deletion of C/EBPβ in oncogenic Ras skin tumors is a synthetic lethal event, making it a promising target for future potential anticancer therapies.

Identification of genes associated with matrix metalloproteinases in invasive lung adenocarcinoma

The aim of the present study was to identify genes with similar function to that of matrix metalloproteinases (MMPs) in invasive lung adenocarcinoma (AC) and to screen the transcription factors that regulate MMPs. The gene expression dataset GSE2514, including 20 invasive lung AC samples and 19 adjacent normal lung samples, was downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were screened using the limma package in R. Genes with similar function to MMPs were identified by K-means clustering. Their correlations with MMPs were validated using Pearson correlation analysis. The expression of MMPs in lung cancer and normal tissues was evaluated by western blot analysis. Protein-protein interaction (PPI) network and transcriptional regulatory network analyses were performed with Retrieval of Interacting Genes and Database for Annotation, Visualization and Integrated Discovery, respectively. As a result, 269 DEGs were identified between invasive lung AC samples and normal lung samples, including 78 upregulated and 191 downregulated genes. Four MMPs (MMP1, MMP7, MMP9 and MMP12), which were upregulated in lung AC, were clustered into one group with other genes, including NAD(P)H quinone oxidoreductase 1, claudin 3 (CLDN3), S100 calcium-binding protein P, serine protease inhibitor Kazal type 1, collagen type XI α 1 chain, periostin and desmoplakin (DSP), following cluster analysis. Pearson correlation analysis further confirmed correlations between MMP9-CLDN3, MMP9-DSP and MMP12-DSP. PPI network analysis also indicated multiple interactions between MMPs-associated genes. Furthermore, MMPs were commonly regulated by CCAAT/enhancer binding protein α transcription factor. These findings may provide further insight into the mechanisms of MMPs in invasive lung AC.

Association of overexpressed karyopherin alpha 2 with poor survival and its contribution to interleukin-1β-induced matrix metalloproteinase expression in oral cancer

BACKGROUND

The purpose of this study was to elucidate the clinicopathological associations and molecular mechanisms of karyopherin alpha 2 (KPNA2) in oral cavity squamous cell carcinoma (SCC) progression.

METHODS

The KPNA2 expressions were analyzed by immunohistochemistry and enzyme-linked immunosorbent assay in 209 tissues and 181 saliva samples, respectively. The functions of KPNA2 in migration and invasion were examined in KPNA2-knowdown cells. The matrix metalloproteinase (MMP) levels were determined by real-time quantitative polymerase chain reaction (qPCR). The subcellular fraction was used to obtain the nuclear distribution of nuclear factor-kappa B (NF-κB).

RESULTS

The KPNA2 overexpression was associated with extranodal extension (P < .05) and poor disease-specific survival in patients with oral cavity SCC (P < .05). The salivary KPNA2 levels were elevated in patients with oral cavity SCC (P < .05). The KPNA2 knockdown reduced cell migration and invasion. This knockdown also suppressed the interleukin (IL)-1β-induced nuclear import of NF-κB and MMP (MMP-1, MMP-3, and MMP-9) transcription.

CONCLUSION

The KPNA2 overexpression is an independent biomarker for poor prognosis of oral cavity SCC and is required for MMP-mediated metastasis.

C/EBPβ Promotion of MMP3-Dependent Tumor Cell Invasion and Association with Metastasis in Colorectal Cancer

AIMS

Tumor metastasis is a significant obstacle to curing colorectal cancer (CRC). C/EBPβ is thought to play an important role in CRC invasion and metastasis. In this study, we assessed whether C/EBPβ-mediated tumor invasion was dependent on MMP3, the expression of which is upregulated by C/EBPβ. We then determined whether C/EBPβ upregulation was associated with MMP3 levels and metastatic status in human CRC patients.

MATERIALS AND METHODS

A total of 102 patients were recruited for this study. mRNA and protein levels of C/EBPβ and MMP3 in CRC cell lines and patient specimens were determined by reverse transcription-polymerase chain reaction and western blot, respectively. Tumor cell invasion was analyzed using an in vitro Matrigel Invasion Assay. The correlation between C/EBPβ and MMP3 expression was determined by Pearson's correlation analysis.

RESULTS

Both mRNA and protein levels of MMP3 were upregulated by C/EBPβ overexpression and downregulated by C/EBPβ siRNA in HCT116 CRC cell cultures. C/EBPβ-enhanced tumor cell invasion was inhibited by MMP3 siRNA. In human CRC patients, C/EBPβ levels were correlated with MMP3 levels and metastatic status.

CONCLUSIONS

C/EBPβ upregulation promoted tumor cell invasion in an MMP3-dependent manner in vitro and was associated with metastatic status in CRC.

Antcin-H Isolated from Antrodia cinnamomea Inhibits Renal Cancer Cell Invasion Partly through Inactivation of FAK-ERK-C/EBP-β/c-Fos-MMP-7 Pathways

Antcin-H, a natural triterpene, is purified from a famous anticancer medicinal mushroom, Antrodia cinnamomea, in Taiwan. This study showed that antcin-H inhibited the growth of human renal carcinoma 786-0 cells; the IC₅₀ value (for 48 h) was 170 μM. Besides, the migration and invasion of 786-0 cells were suppressed by antcin-H under noncytotoxic concentrations (<100 μM); these events were accompanied by inhibition of FAK and Src kinase activities, decrease of paxillin phosphorylation, impairment of lamellipodium formation, and upregulation of TIMPs and downregulation of MMPs, especially MMP-7 expression. Luciferase reporter assay showed that antcin-H repressed the MMP-7 promoter activity, in parallel to inhibiting c-Fos/AP-1 and C/EBP-β transactivation abilities. Moreover, antcin-H suppressed the activity of ERK1/2 and decreased the binding ability of C/EBP-β and c-Fos on the upstream/enhancer region of MMP-7 promoter. Overall, this study demonstrated that the anti-invasive effect of antcin-H in human renal carcinoma 786-0 cells might be at least in part by abrogating focal adhesion complex and lamellipodium formation through inhibiting the Src/FAK-paxillin signaling pathways and decreasing MMP-7 expression through suppressing the ERK1/2-AP-1/c-Fos and C/EBP-β signaling axis. Our findings provide the evidence that antcin-H may be an active component existing in A. cinnamomea with anticancer effect.

Endotoxin induced TLR4 signaling downregulates CYP19A1 expression through CEBPB in buffalo granulosa cells

Estrogen is essential for growth and development of ovarian follicles. Infections associated with E. coli or Endotoxin (LPS) suppress estradiol production by the downregulation of CYP19A1 expression. However, the molecular mechanism of its down regulation is not yet known. To elucidate the molecular mechanisms of LPS-mediated downregulation of CYP19A1 gene expression, we studied the effect of LPS and TLR4 signaling pathway inhibitor (OxPAPC, OxPAPC-Oxidized 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine) on CYP19A1 expression, and expression of CEBPB and CEBPB binding on CYP19A1 proximal promoter (CYP19A1 PII) in buffalo granulosa cells in vitro. The results showed that LPS (1μg/ml) significantly declined the expression of CYP19A1 gene. In further experiments, inhibitor studies confirmed the involvement of TLR4 in LPS induced CYP19A1 gene down regulation in buffalo granulosa cells. LPS promoted higher levels of CEBPB at cellular and nuclear level in granulosa cells. Chromatin immunoprecipitation results showed, that LPS induces higher amount of CEBPB binding on the CYP19A1 PII. Further, TLR4 inhibitor attenuated the LPS induced implications. In conclusion, our results demonstrated that CEBPB could be a potential regulator for LPS mediated downregulation of CYP19A1 and decline of 17-beta estradiol levels in buffalo granulosa cells.

CCAAT/enhancer binding protein β (C/EBPβ) regulates the transcription of growth arrest and DNA damage-inducible protein 45 β (GADD45β) in articular chondrocytes

Osteoarthritis (OA) is a whole joint disease characterized by cartilage degradation, which causes pain and disability in older adults. Our previous work showed that growth arrest and DNA damage-inducible protein 45 β (GADD45β) is upregulated in chondrocyte clusters in OA cartilage, especially in the early stage of this disease. CCAAT/enhancer binding protein β (C/EBPβ) is expressed in the hypertrophic growth plate chondrocytes and functions in synergy with GADD45β. Here, the presence and localization of these proteins was assessed by immunohistochemistry using articular cartilage from OA patients, revealing colocalization of C/EBPβ and GADD45β in OA chondrocytes. GADD45β promoter analysis was performed to determine whether C/EBPβ directly regulates GADD45β transcription. Furthermore, we analyzed the effect of C/EBPβ on Gadd45β gene regulation in articular chondrocytes in vivo and in vitro. Immunohistochemical analysis of C/ebpβ-haploinsufficient mice (C/ebpβ(+/-)) cartilage showed that C/ebpβ haploinsufficiency led to reduced Gadd45β gene expression in these cells. In vitro, we evaluated the effects of conditional C/EBPβ overexpression driven by the cartilage oligomeric matrix protein (Comp) promoter in mComp-tTA;pTRE-Tight-BI-DsRed-mC/ebpβ transgenic mice. C/EBPβ overexpression significantly stimulated Gadd45β gene expression in articular chondrocytes. Taken together, our data demonstrate that C/EBPβ plays a central role in controlling Gadd45β gene expression in these cells.

Licochalcone A inhibits the migration and invasion of human lung cancer cells via inactivation of the Akt signaling pathway with downregulation of MMP-1/-3 expression

Licochalcone A (LicA), a major phenolic constituent of Glycyrrhiza inflata, has been reported to exhibit anti-tumor, anti-inflammatory, and anti-metastatic properties in various cancer cells and animal models. The aim of this study was to determine the anti-tumor effects of LicA on lung cancer cells. The results indicated that LicA exhibited effective inhibition of cell migration and invasion of A549 and H460 cells under non-cytotoxic concentrations. Furthermore, LicA was also found to significantly inhibit the proteins and messenger RNA (mRNA) expression of MMP-1 and MMP-3 in A549 cells. Moreover, treatment of A549 cells with LicA-inhibited activation of the phosphorylation of Akt and inhibition of Akt by LY294002 (PI3K inhibitor) or transfection with the constitutive active-Akt (CA-Akt) expression vector significantly abolished the LicA-inhibited migration and invasion through activation of the Akt pathway. Further mechanistic studies revealed that LicA inhibits Akt signaling pathways and downstream transcription factors Sp1 expression. These findings imply a critical role for Akt inhibition in the LicA-inhibited migration and invasion of lung cancer cells. Thus, LicA might be used as an anti-invasive agent in the treatment of lung cancer.

EGF-induced C/EBPβ participates in EMT by decreasing the expression of miR-203 in esophageal squamous cell carcinoma cells

Epithelial-mesenchymal transition (EMT) is a developmental program that is associated with esophageal squamous cell carcinoma (ESCC) progression and metastasis. Recently, C/EBPβ has been reported to be an EMT inducer in cancer. However, the detailed molecular mechanisms remain unclear. Here, we report for the first time, that the truncated CCAAT-enhancer-binding protein β (C/EBPβ) LIP isoform is abnormally overexpressed and correlated with cancer metastasis in clinical specimens of human ESCC. Furthermore, we demonstrate that C/EBPβ LIP mediates epithelial growth factor (EGF)-induced EMT and increases migration and invasion of esophageal cancer cells in a manner that is dependent on miR-203 inactivation. Finally, we identified miR-203 as a direct target of C/EBPβ LIP. Disruption of C/EBPβ LIP attenuated the EGF-mediated decrease in miR-203, whereas overexpression of C/EBPβ LIP alone markedly suppressed miR-203. In addition, we demonstrated that C/EBPβ LIP inhibited miR-203 transcription by directly interacting with a conserved distal regulatory element upstream of the miR-203 locus, and in doing so, orchestrated chromatin remodeling. In conclusion, our results have revealed a new regulatory mechanism that involves C/EBPβ-LIP-mediated downregulation of miR-203, which plays a key role in EMT and metastasis.

A dual tyrosine kinase inhibitor lapatinib suppresses overexpression of matrix metallopeptidase 1 (MMP1) in endometrial cancer

Endometrial cancers have been recently molecularly characterized; amplifications of human epidermal growth factor receptor 2 (HER2) were seen in 25 % of the serous-like tumors, and mutations in the PI(3)K/AKT pathways were seen in 93 % of endometrioid tumors. These new findings about endometrial cancer suggest a potential for targeted therapy with lapatinib, a dual inhibitor of epidermal growth factor receptor and HER2 tyrosine kinases. However, the clinical efficacy of lapatinib in phase II clinical trials for the treatment of endometrial cancers was only minimal. In this study, we investigated the signaling changes induced by lapatinib in endometrial cancer, which may improve its therapeutic efficacy in molecularly selected patient groups. We identified one of the final molecular targets of lapatinib to be interstitial collagenase, matrix metallopeptidase 1 (MMP1). Lapatinib suppresses MMP1 through EGFR and HER2, and their downstream ERK and AKT signaling pathways. We also found that the activating protein-1 binding site of MMP1 promoter is required for its transcriptional activation, which may be unique for endometrial cancers. Our results also showed that forced expression of active ERK or active AKT mutants rescued MMP1 expression from lapatinib suppression, further suggesting the importance of molecular selection to find appropriate patients with endometrial cancer for future clinical trials with any targeted therapies.

KEY MESSAGE

MMP1 expression was high in tissues and sera in patients with endometrial cancer. Lapatinib inhibited MMP1 via both HER2 and EGFR signaling pathways. Both AKT and ERK need to be inhibited for efficient MMP1 suppression by lapatinib. Activating protein-1 (AP-1) binding site of MMP1 promoter is uniquely required for MMP1 activation in endometrial cancer. Suppression of both c-fos and c-Jun bound to AP1 binding site is required for lapatinib inhibition.

Structure-based design, synthesis, molecular docking, and biological activities of 2-(3-benzoylphenyl) propanoic acid derivatives as dual mechanism drugs

Purpose:

2-(3-benzoyl phenyl)propanohydroxamic acid (2) and 2-{3-[(hydroxyimino)(phenyl)methyl]phenyl}propanoic acid (3) were synthesized from non-steroidal anti-inflammatory drug, ketoprofen as dual-mechanism drugs.

Materials and Methods:

Structures of the synthesized compounds were established by IR, ¹H NMR, and mass spectroscopy. Both compounds were screened for their anti-inflammatory activity in rat paw edema model and in vitro antitumor activity against 60 human tumor cell lines. Flexible ligand docking studies were performed with different matrix metalloproteinases and cyclooxygenases to gain an insight into the structural preferences for their inhibition.

Results:

Compound (2) proved out to be more potent than ketoprofen in rat paw edema model. Both compounds showed moderate anticancer activity ranging from 1% to 23% inhibition of growth in 38 cell lines of 8 tumor subpanels at 10 μM concentration in a single dose experiment. Hydroxamic acid analogue was found to be more potent than ketoximic analogue in terms of its antitumor activity.

Conclusion:

Analysis of docking results together with experimental findings provide a good explanation for the biological activities associated with synthesized compounds which may be fruitful in designing dual-target-directed drugs that may inhibit cyclooxygenases and MMPs for the treatment of cancer.

Extracellular signal-regulated kinase 2 mediates the expression of granulocyte colony-stimulating factor in invasive cancer cells

Granulocyte colony-stimulating factor (G-CSF) affects granulopoiesis and is important for mobilizing neutrophils into blood circulation. Due to the hematopoietic properties of G-CSF, it has been widely used to clinically treat chemotherapy-induced neutropenia. However, G-CSF can promote tumors by inhibiting innate and adaptive immunity and enhancing angiogenesis and neoplastic growth. Most G-CSF-producing tumors are associated with a poor prognosis. This indicates that G-CSF promotes cancer progression. Thus, identifying regulatory molecules involved in tumor-derived G-CSF expression may provide therapeutic targets for cancer treatment. This study identified considerable G-CSF expression in malignant breast, lung and oral cancer cells. However, G-CSF expression was barely detectable in non-invasive cell lines. Expression of G-CSF mRNA and protein increased during exposure to tumor necrosis factor-α (TNF-α). Treatment with U0126 (a mitogen-activated protein kinase inhibitor) drastically reduced basal levels of G-CSF and TNF-α-induced G-CSF in aggressive cancer cells. This study also showed that knockdown of extracellular signal-regulated kinase (ERK) 2 by shRNA was necessary and sufficient to eliminate the expression of tumor-derived G-CSF. This did not apply to ERK1. Therefore, ERK2 (but not ERK1) is responsible for the transcriptional regulation of tumor-derived G-CSF. The results indicate the pharmaceutical value of specific ERK2 inhibitors in treating patients with G-CSF-producing tumors.

Role of matrix metalloproteinase-10 in the BMP-2 inducing osteoblastic differentiation

Fibrodysplasia ossificans progressiva (FOP) is a skeletal disorder with progressive heterotopic ossification in skeletal muscle. A mutation causing constitutive activation in a bone morphogenetic protein (BMP) type 1 receptor [ALK2(R206H)] is found in most patients with FOP. However, the details in the heterotopic ossification of muscle in FOP and the role of matrix metalloproteinase-10 (MMP-10) in bone remain to be fully elucidated. In the present study, we investigated the role of MMP-10 in the differentiation of mouse myoblastic C2C12 cells into osteoblasts. MMP-10 was extracted as a factor, whose expression was most extensively enhanced by ALK2 (R206H) transfection in C2C12 cells. MMP-10 significantly augmented the levels of Osterix, type 1 collagen, alkaline phosphatase (ALP) and osteocalcin mRNA as well as ALP activity enhanced by BMP-2 in C2C12 cells. Moreover, a reduction in endogenous MMP-10 levels by siRNA significantly decreased the levels of Runx2, Osterix, type 1 collagen, ALP and osteocalcin mRNA enhanced by BMP-2 in these cells. In addition, MMP-10 increased the phosphorylation of Smad1/5/8 as well as enhanced the levels of Smad6 and Smad7 mRNA induced by BMP-2. In conclusion, the present study first demonstrated that MMP-10 promotes the differentiation of myoblasts into osteoblasts by interacting with the BMP signaling pathway. MMP-10 may play some important role in the heterotopic ossification of muscle in FOP.

Deficiency of CCAAT/enhancer binding protein family DNA binding prevents malignant conversion of adenoma to carcinoma in NNK-induced lung carcinogenesis in the mouse

BACKGROUND

The CCAAT/enhancer binding proteins (C/EBPs) play important roles in carcinogenesis of many tumors including the lung. Since multiple C/EBPs are expressed in lung, the combinatorial expression of these C/EBPs on lung carcinogenesis is not known.

METHODS

A transgenic mouse line expressing a dominant negative A-C/EBP under the promoter of lung epithelial Clara cell secretory protein (CCSP) gene in doxycycline dependent fashion was subjected to 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung carcinogenesis bioassay in the presence and absence of doxycycline, and the effect of abolition of DNA binding activities of C/EBPs on lung carcinogenesis was examined.

RESULTS

A-C/EBP expression was found not to interfere with tumor development; however, it suppressed the malignant conversion of adenoma to carcinoma during NNK-induced lung carcinogenesis. The results suggested that Ki67 may be used as a marker for lung carcinomas in mouse.

CONCLUSIONS

The DNA binding of C/EBP family members can be used as a potential molecular target for lung cancer therapy.

Interleukin-1β mediates metalloproteinase-dependent renal cell carcinoma tumor cell invasion through the activation of CCAAT enhancer binding protein β

Effective treatment of metastatic renal cell carcinoma (RCC) remains a major medical concern, as these tumors are refractory to standard therapies and prognosis is poor. Although molecularly targeted therapies have shown some promise in the treatment of this disease, advanced RCC tumors often develop resistance to these drugs. Dissecting the molecular mechanisms underlying the progression to advanced disease is necessary to design alternative and improved treatment strategies. Tumor-associated macrophages (TAMs) found in aggressive RCC tumors produce a variety of inflammatory cytokines, including interleukin-1β (IL-1β). Moreover, the presence of TAMs and high serum levels of IL-1β in RCC patients correlate with advanced disease. We hypothesized that IL-1β in the tumor microenvironment promotes the development of aggressive RCC tumors by directing affecting tumor epithelial cells. To address this, we investigated the role of IL-1β in mediating RCC tumor cell invasion as a measure of tumor progression. We report that IL-1β induced tumor cell invasion of RCC cells through a process that was dependent on the activity of matrix metalloproteinases (MMPs) and was independent of migration rate. Specifically, IL-1β induced the expression of MMP-1, MMP-3, MMP-10, and MT1-MMP in a mechanism dependent on IL-1β activation of the transcription factor CCAAT enhancer binding protein β (CEBPβ). Consistent with its role in MMP gene expression, CEBPβ knockdown significantly reduced invasion, but not migration, of RCC tumor cells. These results identify the IL-1β /CEBPβ/MMP pathway as a putative target in the design of anti-metastatic therapies for the treatment of advanced RCC.

The polymorphism rs944289 predisposes to papillary thyroid carcinoma through a large intergenic noncoding RNA gene of tumor suppressor type

A genome-wide association study of papillary thyroid carcinoma (PTC) pinpointed two independent SNPs (rs944289 and rs965513) located in regions containing no annotated genes (14q13.3 and 9q22.33, respectively). Here, we describe a unique, long, intergenic, noncoding RNA gene (lincRNA) named Papillary Thyroid Carcinoma Susceptibility Candidate 3 (PTCSC3) located 3.2 kb downstream of rs944289 at 14q.13.3 and the expression of which is strictly thyroid specific. By quantitative PCR, PTCSC3 expression was strongly down-regulated (P = 2.84 × 10(-14)) in thyroid tumor tissue of 46 PTC patients and the risk allele (T) was associated with the strongest suppression (genotype [TT] (n = 21) vs. [CT] (n = 19), P = 0.004). In adjacent unaffected thyroid tissue, the genotype [TT] was associated with up-regulation of PTCSC3 ([TT] (n = 21) vs. [CT] (n = 19), P = 0.034). The SNP rs944289 was located in a binding site for the CCAAT/enhancer binding proteins (C/EBP) α and β. The risk allele destroyed the binding site in silico. Both C/EBPα and C/EBPβ activated the PTCSC3 promoter in reporter assays (P = 0.0009 and P = 0.0014, respectively) and the risk allele reduced the activation compared with the nonrisk allele (C) (P = 0.026 and P = 0.048, respectively). Restoration of PTCSC3 expression in PTC cell line cells (TPC-1 and BCPAP) inhibited cell growth (P = 0.002 and P = 0.019, respectively) and affected the expression of genes involved in DNA replication, recombination and repair, cellular movement, tumor morphology, and cell death. Our data suggest that SNP rs944289 predisposes to PTC through a previously uncharacterized, long intergenic noncoding RNA gene (PTCSC3) that has the characteristics of a tumor suppressor.

Ginsenoside Rh1 suppresses matrix metalloproteinase-1 expression through inhibition of activator protein-1 and mitogen-activated protein kinase signaling pathway in human hepatocellular carcinoma cells

Invasion and metastasis are the major causes of treatment failure in patients with cancer. Here, we investigated the effects of ginsenoside Rh1 on tumor invasion and metastasis in human hepatocellular carcinoma HepG2 cells and its possible mechanism of action. Rh1 showed concentration- and time-dependent inhibition of HepG2 cell migration and invasion. Matrix metalloproteinase-1 (MMP-1) gene expression and its promoter activity were also concentration-dependently inhibited by Rh1 treatment. The inhibitory effect of Rh1 on MMP-1 expression was due to inactivation of the mitogen-activated protein kinases (MAPKs) ERK, JNK, and p38 MAPK. By transient transfection analysis with the MMP-1 promoter (-2846 to -29 nt) and AP-1 promoter, MMP-1 and AP-1 promoter activities were induced by phorbol myristate acetate (PMA) but were significantly inhibited by PD98059 (ERK1/2 inhibitor) or SP600125 (JNK inhibitor). The induction of MMP-1 and AP-1 promoters by PMA was attenuated by Rh1, and both promoter activities were synergistically inhibited by co-treatment with PD98059. To evaluate the effects of Rh1 on AP-1 dimers, expression analysis and electrophoretic mobility shift (EMSA) assay using radiolabeled AP-1-specific oligomers at proximal site (-73 nt) and distal site (-1600 nt) of the MMP-1 promoter were performed. The results showed that Rh1 inhibited the expression of c-Jun and c-Fos but did not affect the DNA binding ability of AP-1-specific oligomers. However, Rh1 attenuated the stability of c-Jun. Therefore, Rh1 has potential for development of novel chemotherapeutic agents for treatment of malignant cancers, including early hepatocellular carcinoma related to MMP-1 expression.

Guanylate binding protein 1 is a novel effector of EGFR-driven invasion in glioblastoma

Although GBP1 (guanylate binding protein 1) was among the first interferon-inducible proteins identified, its function is still largely unknown. Epidermal growth factor receptor (EGFR) activation by amplification or mutation is one of the most frequent genetic lesions in a variety of human tumors. These include glioblastoma multiforme (GBM), which is characterized by independent but interrelated features of extensive invasion into normal brain parenchyma, rapid growth, necrosis, and angiogenesis. In this study, we show that EGFR activation promoted GBP1 expression in GBM cell lines through a signaling pathway involving Src and p38 mitogen-activated protein kinase. Moreover, we identified YY1 (Yin Yang 1) as the downstream transcriptional regulator regulating EGFR-driven GBP1 expression. GBP1 was required for EGFR-mediated MMP1 (matrix metalloproteinase 1) expression and glioma cell invasion in vitro. Although deregulation of GBP1 expression did not affect glioma cell proliferation, overexpression of GBP1 enhanced glioma cell invasion through MMP1 induction, which required its C-terminal helical domain and was independent of its GTPase activity. Reducing GBP1 levels by RNA interference in invasive GBM cells also markedly inhibited their ability to infiltrate the brain parenchyma of mice. GBP1 expression was high and positively correlated with EGFR expression in human GBM tumors and cell lines, particularly those of the neural subtype. Together, these findings establish GBP1 as a previously unknown link between EGFR activity and MMP1 expression and nominate it as a novel potential therapeutic target for inhibiting GBM invasion.

Phosphorylated c-Jun and Fra-1 induce matrix metalloproteinase-1 and thereby regulate invasion activity of 143B osteosarcoma cells

Osteosarcoma is the most common primary malignancy of bone and patients often develop pulmonary metastases. Despite the advances in surgical and medical management, the mechanisms underlying human osteosarcoma progression and metastasis remain to be elucidated. Gene expression profiles were compared by the cDNA microarray technique between two different human osteosarcoma sublines, MNNG/HOS and 143B, which differ greatly in spontaneous pulmonary metastatic potential. Here we report an enhanced expression of matrix metalloproteinase (MMP)-1 in the highly metastatic human osteosarcoma cell line 143B. Moreover, the in vitro invasion activity of 143B cells was MMP-1-dependent. The activator protein (AP)-1 binding site in the MMP-1 gene promoter was required for the constitutive expression of MMP-1 in 143B cells. Two AP-1 components, c-Jun and Fra-1, were phosphorylated, and bound to the AP-1 binding site of the MMP-1 promoter in 143B cells. Activated c-Jun and Fra-1 were essential for MMP-1 gene expression in 143B cells. Mitogen-activated protein kinase pathways including the c-Jun NH(2)-terminal kinase and the extracellular signal-regulated kinase activate c-Jun and Fra-1 and thereby regulate c-Jun/Fra-1 mediated events, establishing the mitogen-activated protein kinase/AP-1/MMP-1 axis as important in 143B cells. These data suggest that MMP-1 plays a central role in osteosarcoma invasion. Accordingly, MMP-1 might be a biomarker and therapeutic target for invasive osteosarcomas and pulmonary metastases.