Connective tissue growth factor is overexpressed in esophageal squamous cell carcinoma and promotes tumorigenicity through beta-catenin-T-cell factor/Lef signaling

Estrogenic GPR30 signalling induces proliferation and migration of breast cancer cells through CTGF

The steroid hormone oestrogen can signal through several receptors and pathways. Although the transcriptional responses mediated by the nuclear oestrogen receptors (ER) have been extensively characterized, the changes in gene expression elicited by signalling through the membrane-associated ER GPR30 have not been studied. We show here for ER-negative human breast cancer cells that the activation of GPR30 signalling by oestrogen or by hydroxytamoxifen (OHT), an ER antagonist but GPR30 agonist, induces a transcription factor network, which resembles that induced by serum in fibroblasts. The most strongly induced gene, CTGF, appears to be a target of these transcription factors. We found that the secreted factor connective tissue growth factor (CTGF) not only contributes to promote proliferation but also mediates the GPR30-induced stimulation of cell migration. These results provide a framework for understanding the physiological and pathological functions of GPR30. As the activation of GPR30 by OHT also induces CTGF in fibroblasts from breast tumour biopsies, these pathways may be involved in promoting aggressive behaviour of breast tumours in response to endogenous oestrogens or to OHT being used for endocrine therapy.

Expression and its significance of connective tissue growth factor and transforming growth factorβ1 in hepatic tissues of non-alcoholic steatohepatitis

AIM: To investigate the expression of connective tissue growth factor (CTGF) and transforming growth factorβ1 (TGFβ1) in non-alcoholic steatohepatitis hepatic tissue and to explore correlation between them during hepatic fibrosis.

METHODS: HE staining, RT-PCR and immunohistochemistry methods were used to measure TGFβ1 and CTGF mRNA expression levels in liver tissue of 21 patients with non-alcoholic steatohepatitis and 10 normal controls meanwhile hepatic histopathological changes were evaluated.

RESULTS: The optical microscopic analysis indicated that liver inflammation and fibrosis were apparently present in non-alcoholic steatohepatitis group (NASH group). And immunohistochemistry analysis revealed that the expressions of TGFβ1 and CTGF in hepatic tissue were significantly higher in NASH group than in normal control group (109.52 ± 4.50 vs 114.47 ± 2.00, 117.07 ± 3.60 vs 125.05 ± 3.37, both P < 0.01). TGFβ1 mRNA and CTGF mRNA expression were enhanced significantly in NASH group, compared with the control group (0.66 ± 0.07 vs 0.46 ± 0.04, 0.59 ± 0.08 vs 0.41 ± 0.05, both P < 0.05).

CONCLUSION: The enhanced expressions of TGFβ1 and CTGF in hepatic liver tissue of non-alcoholic steatohepatitis patients might be involved in fatty fibrosis. CTGF plays an important role in diagnosis and treatment of non-alcoholic fatty liver disease.

CCN2 YAPs at cancer

The YAP transcription coactivator has been implicated as an oncogene and is amplified in human cancers. Previously, it has been shown that CCN2 (connective tissue growth factor, CTGF) is a target of the tumor promoting YAP and its transcription factor target TEAD. A recent report in Genes and Development by Zhao and colleagues (Genes Dev 22:1962-1971 2008) has extended these initial observations to show that CCN2 plays an important role in the growth-promoting function of YAP. These data confirm the role of CCN2 as a key oncogenic mediator. This report briefly summarizes these findings.

Functions and mechanisms of action of CCN matricellular proteins

Members of the CCN (CYR61/CTGF/NOV) family have emerged as dynamically expressed, extracellular matrix-associated proteins that play critical roles in cardiovascular and skeletal development, injury repair, fibrotic diseases and cancer. The synthesis of CCN proteins is highly inducible by serum growth factors, cytokines, and environmental stresses such as hypoxia, UV exposure, and mechanical stretch. Consisting of six secreted proteins in vertebrate species, CCNs are typically comprised of four conserved cysteine-rich modular domains. They function primarily through direct binding to specific integrin receptors and heparan sulfate proteoglycans, thereby triggering signal transduction events that culminate in the regulation of cell adhesion, migration, proliferation, gene expression, differentiation, and survival. CCN proteins can also modulate the activities of several growth factors and cytokines, including TGF-beta, TNFalpha, VEGF, BMPs, and Wnt proteins, and may thereby regulate a broad array of biological processes. Recent studies have uncovered novel CCN activities unexpected for matricellular proteins, including their ability to induce apoptosis as cell adhesion substrates, to dictate the cytotoxicity of inflammatory cytokines such as TNFalpha, and to promote hematopoietic stem cell self-renewal. As potent regulators of angiogenesis and chondrogenesis, CCNs are essential for successful cardiovascular and skeletal development during embryogenesis. In the adult, the expression of CCN proteins is associated with injury repair and inflammation, and has been proposed as diagnostic or prognostic markers for diabetic nephropathy, hepatic fibrosis, systemic sclerosis, and several types of cancer. Targeting CCN signaling pathways may hold promise as a strategy of rational therapeutic design.

Connective tissue growth factor: structure-function relationships of a mosaic, multifunctional protein

Connective tissue growth factor (CTGF) is a member of the CCN family of six small secreted, cysteine-rich growth factors. The unique modular structure encompasses distinct functional domains which enable CTGF to interact with growth factors, surface receptors and matrix components. Widely expressed, CTGF has critical roles in embryonic development and the maintenance of normal cell and connective tissue function. It is also important for tissue repair following injury, and has been implicated in common diseases including atherosclerosis, pulmonary and renal fibrotic disorders and cancer. Factors that regulate CTGF transcription in response to exogenous stimuli, as well as downstream signalling pathways, have been described. However, only recently have studies begun to unravel how the functional domains within the CTGF modules orchestrate signals and control key biological processes. This article highlights how the structural and functional domains of CTGF and CTGF cleavage fragments integrate multiple extracellular events into cell signals.