Connective Tissue Growth Factor Antibody Research Articles

Effect of antibody-mediated connective tissue growth factor neutralization on lung edema in ventilator-induced lung injury in rats.

Acute respiratory distress syndrome (ARDS) is characterized by alveolar edema that can progress to septal fibrosis. Mechanical ventilation can augment lung injury, termed ventilator-induced lung injury (VILI). Connective tissue growth factor (CTGF), a mediator of fibrosis, is increased in ARDS patients. Blocking CTGF inhibits fibrosis and possibly vascular leakage. This study investigated whether neutralizing CTGF reduces pulmonary edema in VILI. Following LPS administration, rats were mechanically ventilated for 6h with low (6mL/kg; low VT) or moderate (10mL/kg; mod VT) tidal volume and treated with a neutralizing CTGF antibody (FG-3154) or placebo lgG (vehicle). Control rats without LPS were ventilated for 6h with low VT. Lung wet-to-dry weight ratio, FITC-labeled dextran permeability, histopathology, and soluble RAGE were determined. VILI was characterized by reduced PaO2/FiO2 ratio (low VT: 540 [381-661] vs. control: 693 [620-754], p < 0.05), increased wet-to-dry weight ratio (low VT: 4.8 [4.6-4.9] vs. control: 4.5 [4.4-4.6], p < 0.05), pneumonia (low VT: 30 [0-58] vs. control: 0 [0-0]%, p < 0.05) and interstitial inflammation (low VT: 2 [1-3] vs. control: 1 [0-1], p < 0.05). FG-3154 did not affect wet-to-dry weight ratio (mod VT + FG-3154: 4.8 [4.7-5.0] vs. mod VT + vehicle: 4.8 [4.8-5.0], p > 0.99), extravasated dextrans (mod VT + FG-3154: 0.06 [0.04-0.09] vs. mod VT + vehicle: 0.04 [0.03-0.09] µg/mg tissue, p > 0.99), sRAGE (mod VT + FG-3154: 1865 [1628-2252] vs. mod VT + vehicle: 1885 [1695-2159] pg/mL, p > 0.99) or histopathology. 'Double hit' VILI was characterized by inflammation, impaired oxygenation, pulmonary edema and histopathological lung injury. Blocking CTGF does not improve oxygenation nor reduce pulmonary edema in rats with VILI.

The Inhibitory Effect of Connective Tissue Growth Factor Antibody on Postoperative Fibrosis in a Rabbit Model of Trabeculectomy.

To compare the efficacy of subconjunctival injection of an anti-connective tissue growth factor antibody (anti-CTGF) versus mitomycin-C (MMC) and placebo in reducing scar formation in a rabbit model of trabeculectomy. A total of 14 rabbits were included. Nine rabbits underwent trabeculectomy with subconjunctival injections of either anti-CTGF antibody, MMC, or balanced salt solution (BSS), each administered in three eyes, before peritomy. The anti-CTGF group received a repeated dose of the antibody five days after surgery. All nine rabbits were euthanized on day 14; the globes were stained with hematoxylin & eosin, Masson's Trichrome, and immunohistochemistry for detecting alpha-smooth muscle (α-SMA) actin. RNA extraction was performed on five eyes of the remaining rabbits which included one eye without any surgery, one eye 5 hr after trabeculectomy without any injection, one eye five days after trabeculectomy without any injection, and two eyes five days after trabeculectomy with administration of MMC and BSS, respectively. The mean bleb area in the anti-CTGF, MMC, and control groups was 3.8 1.45, 5.9 1.4, and 3.5 1.9 mm2, respectively. Collagenous tissue was found to occupy the bleb area by 13.7%, 13.5%, and 18.5%, respectively. This ratio was significantly higher in the BSS group (P = 0.04). The expression of CTGF mRNA after 5 hr and five days in eyes undergoing trabeculectomy were significantly more pronounced as compared to the unoperated eye. The mean H-SCORE of α-SMA-immune reactive cells calculated as the grade of staining multiplied by the percentage of immune stained cells was 14.6, 10.22, and 140.58 in the anti-CTGF, MMC, and control groups, respectively. While the control eyes had a significantly higher score (Ps 0.001), the anti-CTGF and MMC groups were comparable (P = 0.87). Based on the results of this animal study, the anti-CTGF antibody injection resulted in a significant reduction in collagenous tissue and myofibroblast cells after trabeculectomy.

Expression of connective tissue growth factor as a prognostic indicator and its possible involvement in the aggressive properties of epithelial ovarian carcinoma.

Recently, connective tissue growth factor (CTGF) was demonstrated to be associated with aggressive characteristics, including proliferation, invasion and metastasis, in a number of malignancies. Here, we investigated the expression and function of CTGF in epithelial ovarian carcinoma (EOC) to clarify its molecular mechanism and clinical significance. Paraffin sections from clinical samples of EOC (N=104) were immunostained with the CTGF antibody, and then the staining positivity was semiquantitatively examined. Moreover, we explored the role of CTGF expression in the migration-promoting effect on and chemoresistance of EOC cells. The results revealed that of the 104 EOC patients, the low and high CTGF staining expression rates were 65 (62.5%) and 39 (37.5%), respectively. Patients belonging to the higher-level CTGF group showed poorer progression-free (PFS) and overall survival (OS) rates than those in the lower-level group [PFS (log-rank: P=0.0076) and OS (log-rank: P=0.0078), respectively]. Multivariable analysis showed that CTGF expression was a significant predictor of poorer PFS and OS [PFS: HR (high vs. low): 1.837, 95% CI: 1.023–3.289 (P=0.0418); OS: HR: 2.141, 95% CI: 1.077–4.296 (P=0.0300)]. In in vitro studies, in acquired paclitaxel (PTX)-resistant EOC cells, the silencing of CTGF expression led to the restoration of PTX sensitivity. Furthermore, we confirmed that the TGF-β-dependent migration-promoting effect on these CTGF-depleted cells was completely inhibited. In conclusion, the results of the present study suggest the possible involvement of CTGF in the migration-promoting effect and chemoresistance of EOC, suggesting that it may be a target for overcoming the malignant properties of EOC.

Radiation-induced pulmonary gene expression changes are attenuated by the CTGF antibody Pamrevlumab

BackgroundFibrosis is a delayed side effect of radiation therapy (RT). Connective tissue growth factor (CTGF) promotes the development of fibrosis in multiple settings, including pulmonary radiation injury.MethodsTo better understand the cellular interactions involved in RT-induced lung injury and the role of CTGF in these responses, microarray expression profiling was performed on lungs of irradiated and non-irradiated mice, including mice treated with the anti-CTGF antibody pamrevlumab (FG-3019). Between group comparisons (Welch’s t-tests) and principal components analyses were performed in Genespring.ResultsAt the mRNA level, the ability of pamrevlumab to prolong survival and ameliorate RT-induced radiologic, histologic and functional lung deficits was correlated with the reversal of a clear enrichment in mast cell, macrophage, dendritic cell and mesenchymal gene signatures. Cytokine, growth factor and matrix remodeling genes that are likely to contribute to RT pneumonitis and fibrosis were elevated by RT and attenuated by pamrevlumab, and likely contribute to the cross-talk between enriched cell-types in injured lung.ConclusionsCTGF inhibition had a normalizing effect on select cell-types, including immune cells not typically regarded as being regulated by CTGF. These results suggest that interactions between RT-recruited cell-types are critical to maintaining the injured state; that CTGF plays a key role in this process; and that pamrevlumab can ameliorate RT-induced lung injury in mice and may provide therapeutic benefit in other immune and fibrotic disorders.

Serum connective tissue growth factor is a highly discriminatory biomarker for the diagnosis of rheumatoid arthritis

BackgroundOur previous proteomic study indicated that connective tissue growth factor (CTGF) may be a potential biomarker for rheumatoid arthritis (RA) diagnosis. The aim was to assess the performance of CTGF as a biomarker of RA.MethodSerum and synovial fluid CTGF was detected using a direct high sensitivity sandwich ELISA kit. Serum CTGF levels were tested for discriminatory capacity and optimal assay cutoffs determined in a training cohort of 98 cases of RA with 103 healthy controls. The assay performance was then validated in a further cohort of 572 patients (with RA (n = 217), ankylosing spondylitis (n = 92), gout (n = 74), osteoarthritis (n = 52), systemic lupus erythematosus (n = 72), or primary Sjögren’s syndrome (pSS) (n = 65)).ResultsSignificant elevation of synovial fluid CTGF concentration was found in RA patients, demonstrating excellent diagnostic ability to predict RA (area under the curve (AUC) = 0.97). Similar results were found in serum CTGF detection. At the optimal cutoff value 88.66 pg/mL, the sensitivity, specificity, and the AUC was 0.86, 0.92, and 0.92, respectively, in the training cohort. Similar performance was observed in the validation cohort, with sensitivity, specificity, positive likelihood, and negative likelihood of 0.82, 0.91, 5.74, and 0.12, respectively. Stronger discriminatory capacity was seen with the combination of CTGF and anti-citrullinated protein antibody (ACPA) (AUC = 0.96) than with either ACPA or rheumatoid factor (RF) alone (AUC = 0.80 or 0.79, respectively). The discriminatory performance of serum CTGF was consistent across all inflammatory conditions tested (AUC >0.92 in all cases), with the sole exception of pSS. Serum CTGF did not vary with symptom duration or disease activity.ConclusionsSerum CTGF is a promising diagnostic biomarker for RA, with performance in the current study better than either ACPA or RF.

Protection of CTGF Antibody Against Diabetic Nephropathy in Mice Via Reducing Glomerular β-Catenin Expression and Podocyte Epithelial-Mesenchymal Transition.

Despite substantial progress in medical care, the morbidity rate of diabetic nephropathy (DN) remains high in patients with diabetes. Evidence suggests that connective tissue growth factor (CTGF) induced podocyte injury may contribute to DN and CTGF inhibition could reduce albuminuria. However, to date the mechanisms involved in the effect of CTGF on podocyte injury have not been fully understood. The aim of this study is to investigate the effects of therapeutic CTGF antibody on glomerular β-catenin expression and podocyte epithelial-mesenchymal transition (EMT) in diabetic mice. C57BL/6J mice were randomly divided into three groups as the following: the control, DN, and DN treated by CTGF antibody group. DN was induced by a single intraperitoneal injection of streptozotocin and then CTGF antibody was administrated three times per week for 8 weeks. Urinary albumin excretion, mesangial proliferation and matrix deposition, and β-catenin expression in glomeruli at mRNA and protein level were all increased in DN mice compared to that in the control. Besides, the development of EMT in podocytes from diabetic mice, demonstrated by the downregulation of nephrin and upregulation of desmin in glomeruli, was detected. Furthermore, blocking CTGF by specific antibody reduced albuminuria, prevented the overexpression of CTGF, as well as β-catenin, in glomeruli and subsequently ameliorated podocyte EMT in DN mice. In summary, this study suggested that CTGF antibody protected podocytes against injury in DN mice by reducing β-catenin overexpression and preventing podocyte EMT, which might provide new insight into the mechanism of CTGF inhibition in the treatment of DN. J. Cell. Biochem. 118: 3706-3712, 2017. © 2017 Wiley Periodicals, Inc.

The effect of connective tissue growth factor (CTGF) and CTGF antibody on collagen secretion of chicken tendon synovial cells

Objective To investigate the effect of CTGF and CTGF antibody in different concentration on collagen secretion of tendon synovial cells. Methods From February, 2014 to August, 2014, tendon synovial cells were obtained from LegHorn chicken tendon synovial tissues and cultured in Petri dish with incremental concentration of CTGF or CTGF antibody, ELISA was used to detect secretion of collagen Ⅰ/Ⅲ. Results The secretion of collagenⅠincreased gradually as the concentration of CTGF elevating from 5 ng/ml to 50 ng/ml, there were significant differences between the groups (P < 0.05) . While the secretion of collagen Ⅲincreased gradually as the concentration of CTGF elevating from 10 ng/ml to 200 ng/ml, no significant difference was observed between the other groups. CollagenⅠof synovial cells showed a downward trend on secretion when cultured with CTGF antibody as the concentration elevating from 8 μg/ml to 32 μg/ml, there were significant differences between the groups (P < 0.05) . While the secretion of collagen Ⅲ showed a downward trend when cultured with CTGF antibody of the concentration 4 μg/ml, there was no significant difference between the other groups. Conclusion CTGF can promote collagen secretion of synovial cells in vitro with an optimal concentration, the concentration was 50 ng/ml (collagen I) , 200 ng/ml (collagen III) . CTGF antibody can inhibit collagen secretion of synovial cell. Key words: Connective tissue growth factor; Synovial cells; Collagen; Chicken

Abstract P310: Connective Tissue Growth Factor Antibody Protects from Adverse Left Ventricular Remodeling Following Myocardial Infarction

Ischemic heart disease (IHD) is the most common cause of death in most Western countries, but the therapies for IHD are lacking. We aimed to determine the potential of connective tissue growth factor (CTGF) antibody in protecting myocardium from long-term deleterious effects of myocardial infarction. Healthy 8-week old mice were subjected to myocardial infarction (MI) and at 1 week post-MI the animals were randomized for treatment with vehicle, metoprolol or CTGF monoclonal antibody. After six weeks of treatment, CTGF antibody treated animals showed significantly better left ventricular (LV) systolic function than the vehicle-treated animals. LV diastolic function or LV dimensions were not affected by treatments. Analysis of cardiac sections revealed no difference in infarct scar size between the experimental groups. However, RT-PCR analysis revealed a decrease in the expression levels of fibrosis-related genes in non-ischemic area in the hearts of CTGF antibody treated animals. In addition, cardiomyocyte size was significantly reduced in LV sections of CTGF antibody treated animals compared to vehicle-treated animals. This was accompanied with a significant decrease in B-type natriuretic peptide mRNA levels in the LV, whereas expression levels of atrial natriuretic peptide or beta-myosin heavy chain were similar in MI groups. There was also a slight decrease in mRNA levels of interleukin-6 and CTGF in the hearts of CTGF antibody treated animals. Treatments had no effect on mRNA levels of transforming growth factor-β1, tumor necrosis factor-α and vascular endothelial growth factor A following MI. In conclusion, CTGF antibody treatment attenuates LV hypertrophy and improves LV systolic function following MI. Blocking CTGF function by a specific antibody may be useful for prevention of adverse myocardial remodeling and heart failure.

Integrin β3 pathway mediated connective tissue growth factor-induced proliferation, migration and extracellular matrix deposition of pulmonary arterial smooth muscle cells

To explore the effects of integrin β3 pathway on the proliferation, migration and extracellular matrix deposition of pulmonary arterial smooth muscle cells (PASMCs) induced by connective tissue growth factor (CTGF). PASMCs of SD Rats were cultured in M199 culture system in vitro and the 3rd-7th passages of PASMCs were used in the experiments. The cells were randomly divided into three groups: (1) CONTROL GROUP: culture system contained no any stimulation factor; (2) CTGF group: culture system was added into 50 ng/ml CTGF; (3) CTGF+ anti-integrin β3 antibody group:culture system was added with 50 ng/ml CTGF and 10 mg/L anti-integrin β3 antibody. The PASMCs were cultured with 50 ng/ml CTGF and anti-integrin β3 antibody (0, 5, 10, 15, 20 mg/L) for 24, 48, 72 and 96 h, the proliferation of PASMCs was detected by WST-1 Cell Proliferation Assay Kit. The migration of PASMCs was observed by Transwell cell test under the phase contrast microscope. RT-PCR assay was applied to detect the mRNA expression of collagenI-α1, collagen III-α1 and fibronectin-1 gene of PASMCs. The expression of fibronectin protein was examined by Western blotting and immunohistochemistry. The results of WST-1 test showed that the anti-integrin β3 antibody inhibited significantly the proliferation of PASMCs induced by CTGF (P < 0.05), among which the inhibition rate of anti-integrin β3 antibody (10 mg/L) was the most significant. Transwell test results showed that CTGF group of PASMCs migration numbers (25 ± 1.57) were higher than that of the control group (11 ± 2.08, P < 0.01); PASMCs migration numbers of CTGF+ integrin β3 antibody group (17 ± 4.16) were less than that of the CTGF group (P < 0.05). Compared with the control group, the mRNA expression of collagen typeI-α1 (4.28 ± 0.33), collagen typeIII-α1 (4.41 ± 0.35), fibronectin-1 (4.05 ± 0.33) of PASMCs was increased in CTGF group, with a time-dependence (P < 0.01); Compared with the CTGF group, the mRNA expression of collagen typeI-α1 (3.38 ± 0.30), collagen typeIII-α1 (3.40 ± 0.30), fibronectin-1 (3.12 ± 0.29) of PASMCs was reduced in CTGF+ anti-integrin β3 antibody group (P < 0.05), which was higher than that of the control group (P < 0.05); Western blot and immunohistochemical tests showed that compared with the control group, CTGF group could stimulate the expression of fibronectin protein of PASMCs (P < 0.01); the anti-integrin β3 antibody could inhibit the expression of fibronectin protein induced by CTGF(P < 0.01), which was more remarkable than that in the control group (P < 0.01). Integrin β3 pathway can mediate CTGF-induced proliferation, migration and extracellular matrix deposition of PASMCs, CTGF-integrin β3 signaling pathway may play an important role in pulmonary vascular remodeling.

Abstract B206: FG-3019, an anti-CTGF antibody, attenuates tumor invasion, delays tumor growth, and prolongs survival alone and in combination with radiation in an orthotopic glioma model.

Abstract Objective: Despite progress in understanding molecular changes in glioblastoma multiforme (GBM), it remains a cancer with poor prognosis in need of better therapy. Pathological features of GBM are explosive growth, angiogenesis and its unique diffuse, infiltrative growth pattern. There is a consensus that cell-matrix-interactions play a pivotal role for infiltrative growth. Connective tissue growth factor (CTGF) is a matricellular protein that is involved in many pathological processes including tumorigenesis and invasion. CTGF modulates cell-matrix-interactions that may allow glioma cells to invade brain parenchyma, degrade the extracellular matrix (ECM), and enhance proliferation and angiogenesis in GBM. High CTGF-expression levels have been reported to correlate with tumor grade, invasiveness and poor patient survival. Here the effects of a human monoclonal anti-CTGF-antibody (FG-3019) were investigated alone and in combination with irradiation in vitro and in vivo in an orthotopic glioma model in mice. Methods and materials: In vitro studies were performed with two established human glioma cell lines, U87MG and T98G, as well as with primary isolated human glioblastoma cancer stem-like cells (CSLCs) cells. The effects of FG-3019 alone and in combination with photon irradiation (6 MV Linac) on clonogenic survival, proliferation, migration, neurosphere formation, and limiting dilution were determined. RNA was isolated from CSLCs and gene expression changes were examined after different treatments using micro-arrays and RT-PCR. In vivo, CSLCs were subcultured as neurospheres and stereotactically implanted into brains of SCID-beige mice. Mice brains were treated with 7Gy single dose radiation +/− FG-3019. The treatment effects were assessed by MRI, survival time and histology. Results: Tumor growth delay in the orthotopic tumor model resulted from treatment with radiation or FG-3019 alone, which was significantly enhanced by combined treatment. Similarly, animal survival was prolonged by each monotherapy and significantly enhanced by the combination. Histology showed that FG-3019 significantly reduced constitutive and radiation-induced tumor invasion into the brain parenchyma. FG-3019 also reduced intracellular CTGF expression, glioma cell proliferation, deposition of different types of collagen and reduced microvessel density. FG-3019 also reduced expression of Nestin and the stem cell marker SOX-2. In vitro, FG-3019 and irradiation reduced clonogenicity, proliferation and migration of U87MG, T98G and CSLCs, which was enhanced by the combination. Gene expression analysis revealed that FG-3019 down regulated tumorigenesis- and tumor-invasion-related genes. Conclusions: The human monoclonal CTGF antibody, FG-3019, shows remarkable anti-tumorigenic and anti-invasive effects in vitro and in vivo in a primary human glioblastoma model growing orthotopically in mice. Our results indicate that FG-3019 alone and in combination with radiotherapy is a promising approach for clinical translation in humans. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B206.

Role of Connective Tissue Growth Factor in the Retinal Vasculature during Development and Ischemia

To investigate the function of connective tissue growth factor (CTGF), a matricellular protein of the CCN (Cyr61/CTGF/Nov) family, in retinal vasculature during development and ischemia. CTGF expression was determined using RT-PCR, immunohistochemistry, and transgenic mice carrying CTGF promoter-driven-GFP. CTGF antibody was intraocularly injected into neonates at postnatal day (P)2, and its effect on retinal angiogenesis was analyzed at P4. Transgenic animals expressing GFP regulated by the glial fibrillary acidic protein promoter were used for astrocyte visualization. Retinal vascular occlusion was introduced by rose Bengal and laser photocoagulation on chimeric mice that were reconstituted with GFP+ bone marrow cells. Vascular repair in response to VEGF-A and CTGF was analyzed. A temporal increase in CTGF at both mRNA and protein levels was observed in the ganglion cell layer and inner nuclear layer during development. Endothelial cells and pericytes were identified as the main cellular sources of CTGF during retinal angiogenesis. CTGF stimulated the migration of astrocytes, retinal endothelial cells, and pericytes in vitro. Inhibition of CTGF by specific antibody affected vascular filopodial extension, growth of the superficial vascular plexus, and astrocyte remodeling. In adult mice, CTGF was prominently expressed in the perivascular cells of arteries. CTGF activated bone marrow-derived perivascular cells and promoted fibrovascular membrane formation in the laser-induced adult retinopathy model. CTGF is expressed in vascular beds and acts on multiple cell types. It is important for vessel growth during early retinal development and promotes the fibrovascular reaction in murine retinal ischemia after laser injury.

Filtering bleb area and intraocular pressure following subconjunctival injection of CTGF antibody after glaucoma filtration surgery in rabbits.

To study the role of connective tissue growth factor (CTGF) antibody in inhibiting bleb scarring after glaucoma filtration surgery (GFS) in rabbit model. GFS was performed on both eyes in five rabbits. One eye of each rabbit was chosen randomly as antibody group and received subconjunctival injection of 0.1mL CTGF antibody (50mg/L) immediately after GFS applied and on the 5 th day after GFS. The other eye of each rabbit as control group was received subconjunctival injection of 0.1mL PBS at the same time as antibody group. On postoperative days 1, 3, 5, 7, 10, and 14, the appearance of filtrating blebs was observed under slit lamp, the area and the intraocular pressure (IOP) were measured with micrometer and applanation tonometer, respectively. On postoperative days 1, 3, 5, 7, 10, and 14, areas of filtrating blebs in antibody group were all larger comparing with the control group (P<0.05) and IOPs of antibody group were lower than the control group (P<0.05). Subconjunctival injection of CTGF antibody can maintain larger bleb area and lower IOP after GFS in rabbit.

Connective Tissue Growth Factor Antibody Therapy Attenuates Hyperoxia-Induced Lung Injury in Neonatal Rats

Despite recent advances in neonatal intensive care and surfactant therapy, bronchopulmonary dysplasia (BPD) continues to be one of the most common long-term pulmonary complications associated with preterm birth. Clinical efforts to prevent and treat BPD have been largely unsuccessful due to its multifactorial nature and poorly understood disease process. Connective tissue growth factor (CTGF) is a matricellular protein that plays an important role in tissue development and remodeling. Previous studies have demonstrated that hyperoxia exposure up-regulates CTGF expression in neonatal rat lungs. Whether CTGF overexpression plays a role in the pathogenesis of BPD, and whether CTGF antagonism has a therapeutic potential for BPD, are unknown. In the present study, we examined CTGF expression in lung autopsy specimens from patients with BPD and control subjects with no BPD. We assessed the effect of a CTGF-neutralizing monoclonal antibody (CTGF Ab) on preventing hyperoxia-induced lung injury in neonatal rats. Our study demonstrates that CTGF expression is increased in BPD lungs. In newborn rats, exposure to 90% oxygen for 14 days resulted in activation of β-catenin signaling, decreased alveolarization and vascular development, and physiological and histological evidence of pulmonary hypertension (PH). However, treatment with CTGF Ab prevented β-catenin signaling activation, improved alveolarization and vascular development, and attenuated PH during hyperoxia. These data indicate that CTGF-β-catenin signaling plays a critical role in the pathogenesis of experimental BPD. CTGF antagonism may offer a novel therapeutic strategy to alleviate BPD and PH in neonates.

Abstract 509: The CTGF antibody FG-3019 blocks CTGF-stimulated migration in ovarian cancer cells

Abstract Ovarian tumors generally arise from the surface epithelium of the ovary, and require interactions with host stroma to promote tumor cell proliferation and expansion. The signaling mechanisms between tumor-associated stroma and adjacent ovarian epithelial tumor cells remain unclear. We have previously analyzed gene expression profiles of laser-capture microdissected stromal cells from normal ovary and ovarian tumors and have demonstrated that normal ovarian stroma undergoes significant gene expression changes in response to the epithelial tumor microenvironment. Connective Tissue Growth Factor (CTGF), a TGF-β-regulated gene, was identified as specifically up-regulated in tumor-associated versus normal stroma. CTGF is a component of the tumor microenvironment with a demonstrated role in tumor progression and metastasis. FG-3019, a fully human monoclonal antibody against CTGF, is currently under clinical investigation in pancreatic cancer. The aim of this current study was to further elucidate the role of CTGF in ovarian cancer and examine its potential as a therapeutic target. We demonstrate that normal ovarian fibroblasts and ovarian cancer-associated fibroblasts treated with TGF-β secreted high levels of CTGF, whereas ovarian cancer epithelial cells secreted significantly lower levels. We next assessed the paracrine effect of CTGF on three different ovarian cancer cell lines, A224, OVCAR3, and SKOV3. Expression of endogenous CTGF is low in these cells which is consistent with the level found in primary ovarian tumor cells. Addition of recombinant CTGF for 6-hr stimulated migration of A224 (443 ± 20.5 vs. 85 ± 24.4 cells), OVCAR3 (104 ± 11.7 vs. 68 ± 30.1 cells) and SKOV3 (334 ± 45.6 vs. 82 ± 16.6 cells) in a transwell migration assay. Addition of the CTGF-blocking antibody FG-3019 significantly inhibited transwell migration in the presence of recombinant CTGF in all three cell lines (from 443 ± 20.5 to 197 ± 65.4 cells in A224, 334 ± 45.6 to 119 ± 29.0 cells in SKOV3 and 104 ± 11.7 to 36 ± 2.5 cells in OVCAR3). However, recombinant CTGF did not promote proliferation of these cell lines. We demonstrate that CTGF may contribute to ovarian tumor biology and that its function can be blocked by FG-3019, thus determining CTGF as a potential therapeutic target in ovarian tumors. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 509. doi:10.1158/1538-7445.AM2011-509

Pasteurella multocida toxin (PMT) activates the ERK signaling pathway, in part, by upregulating CTGF expression

PMT, a 146 kDa bacterial protein, is a potent mitogen and a strong inducer of anchorage‐independent growth for fibroblast and osteoclast cells. We showed that PMT activated the ERK pathway, and that this ERK activation was also detected when quiescent 3T3 cells were treated with conditioned media taken from PMT‐treated cells. These results support the existence of a diffusible factor(s) that mediates ERK activation. Microarray analysis revealed that connective tissue growth factor (CTGF) is the most elevated factor in PMT‐treated cells. CTGF is a 36‐kDa secreted protein and a member of the CCN family. It stimulates cellular proliferation and regulation of angiogenesis and tumorigenesis. Western blot analysis using CTGF antibody revealed a robust elevation of an immunoreactive protein of 36–38 kDa in both cell lysate and conditioned media of PMT‐treated cells. This observed PMT‐induced CTGF elevation was also detected in WT, but not in Gαq/Gα11‐deficient MEF cells. While PMT failed to induce ERK activation in Gαq/Gα11‐deficient MEF cells, the conditioned media can activate ERK in these cells suggesting that PMT upregulates the CTGF protein level and leads to ERK activation.This work was supported, in part, by the Intramural Research Program of the NIH, NHLBI.

Enamel Matrix Derivative Induces Connective Tissue Growth Factor Expression in Human Osteoblastic Cells

Enamel matrix derivative (EMD) stimulates the production of transforming growth factor-beta (TGF-beta), which has been suggested to play a role in mediating the effects of EMD in periodontal tissue regeneration. Connective tissue growth factor (CTGF) is a mediator of TGF-beta and promotes cell development. The interaction between EMD and CTGF is unknown. This study explored the effects of EMD on CTGF expression in human osteoblastic cells and whether the interaction is modulated by the TGF-beta signaling pathway. Also, the roles of CTGF in cell proliferation, cell cycle progression, and mineralized nodule formation of EMD-induced osteoblastic cultures were examined. Human osteoblastic cells (Saos-2) were treated with 25 to 100 microg/ml EMD with or without the addition of TGF-beta inhibitor. CTGF mRNA expression was detected by reverse transcription-polymerase chain reaction (RT-PCR), and CTGF protein levels were assayed by Western blot analysis. In addition, cell cycle progression and DNA synthesis were determined by flow cytometry and 5-bromo-2'-deoxyuridine (BrdU) incorporation following EMD treatment with or without CTGF antibody. Mineralization was examined by alizarin red staining and quantified by elution with cetylpyridinium chloride. Western blot and RT-PCR analysis demonstrated a dose-dependent increase of CTGF expression by EMD. EMD-induced CTGF expression was reduced significantly in the presence of TGF-beta inhibitor. Cell cycle and BrdU analysis revealed an increase in cell proliferation following EMD treatment, which was due to an increase in the percentage of cells in the G2/M phase of the cell cycle. No significant effect was found when anti-CTGF antibody was added. Conversely, mineralization was inhibited significantly in EMD-treated cultures in the presence of anti-CTGF antibody. EMD stimulates CTGF expression, and the interaction is modulated via TGF-beta in osteoblastic cells. Also, CTGF affects EMD-induced osteoblastic mineralization but not cell proliferation. To our knowledge, these results provide novel insight into EMD-CTGF interaction, two biomodifiers that have therapeutic relevance to tissue engineering and regeneration.

Connective tissue growth factor expression and action in human corneal fibroblast cultures and rat corneas after photorefractive keratectomy.

Connective tissue growth factor (CTGF) has been linked to fibrosis in several tissues. In this study, the interactions between CTGF and transforming growth factor (TGF)-beta were assessed in human corneal fibroblasts, and the levels and location of CTGF protein and mRNA were measured during healing of excimer laser ablation wounds in rat corneas. Human corneal fibroblasts were incubated with TGF-beta1, -beta2, and -beta3 isoforms, and CTGF mRNA and protein were measured. CTGF was immunolocalized in the cultured fibroblasts by using a specific antibody. Regulation of collagen synthesis by TGF-beta and CTGF was assessed in human corneal fibroblasts with a neutralizing antibody and an antisense oligonucleotide to CTGF. CTGF mRNA and protein were measured in rat corneas up to day 21 after excimer ablation of the cornea. CTGF protein was immunolocalized in rat corneas after photorefractive keratectomy (PRK), and the presence of CTGF mRNA and protein in ex vivo rat corneal scrapings was established. All three TGF-beta isoforms stimulated expression of CTGF in human corneal fibroblasts, and CTGF was immunolocalized in the cells. Both TGF-beta and CTGF increased collagen synthesis in corneal fibroblasts. Furthermore, CTGF antibody or antisense oligonucleotide blocked TGF-beta-stimulated collagen synthesis. CTGF protein and mRNA increased in rat corneas through day 21 after PRK. CTGF expression was also detected in ex vivo scrapings of rat corneas. These data demonstrate that CTGF is expressed by corneal cells after stimulation by TGF-beta, that CTGF expression increases significantly during corneal wound healing, and that CTGF mediates the effects of TGF-beta induction of collagen synthesis by corneal fibroblasts. These data support the hypothesis that CTGF promotes corneal scar formation and imply that regulating CTGF synthesis and action may be an important goal for reducing corneal scarring.