Tenascin-C promotes the repair of cartilage defects in mice.

BACKGROUND: The effects of tenascin-C (TNC) on cartilage repair were examined in cartilage defect model mice. An in vitro study was also performed to determine the mechanism of cartilage repair with TNC. METHODS: Full-thickness osteochondral defects were filled with TNC (group A: 100 µg/ml, group B: 10 µg/ml, group C: empty). Mice were sacrificed at 1, 2, 3, and 6 weeks postoperatively. Cartilage repair was histologically evaluated using the modified WAKITANI score. Chondrocytes were isolated and cultured, and they were treated with TNC. The expressions of various mRNAs including TNC, inflammatory cytokines, and anabolic and catabolic factors for cartilage were compared by real-time polymerase chain reaction. RESULTS: The defects in group A were covered with hyaline-like cartilage after 3 weeks. Average modified WAKITANI scores were significantly better in group A than in groups B and C at 3 and 6 weeks. TNC upregulated the expressions of endogenous TNC, inflammatory cytokines, and anabolic and catabolic factors for cartilage. TNC downregulated the expression of a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) 5. CONCLUSIONS: Intra-articular injection of full-length TNC repaired cartilage in murine models of full-thickness osteochondral defects. TNC upregulated the expression of ADAMTS4, but downregulated the expression of ADAMTS5 that contributed to cartilage degradation.

Novel Human Tenascin-C Function-Blocking Camel Single Domain Nanobodies.

The extracellular matrix (ECM) molecule Tenascin-C (TNC) is well-known to promote tumor progression by multiple mechanisms. However, reliable TNC detection in tissues of tumor banks remains limited. Therefore, we generated dromedary single-domain nanobodies Nb3 and Nb4 highly specific for human TNC (hTNC) and characterized the interaction with TNC by several approaches including ELISA, western blot, isothermal fluorescence titration and negative electron microscopic imaging. Our results revealed binding of both nanobodies to distinct sequences within fibronectin type III repeats of hTNC. By immunofluroescence and immunohistochemical imaging we observed that both nanobodies detected TNC expression in PFA and paraffin embedded human tissue from ulcerative colitis, solid tumors and liver metastasis. As TNC impairs cell adhesion to fibronectin we determined whether the nanobodies abolished this TNC function. Indeed, Nb3 and Nb4 restored adhesion of tumor and mesangial cells on a fibronectin/TNC substratum. We recently showed that TNC orchestrates the immune-suppressive tumor microenvironment involving chemoretention, causing tethering of CD11c+ myeloid/dendritic cells in the stroma. Here, we document that immobilization of DC2.4 dendritic cells by a CCL21 adsorbed TNC substratum was blocked by both nanobodies. Altogether, our novel TNC specific nanobodies could offer valuable tools for detection of TNC in the clinical practice and may be useful to inhibit the immune-suppressive and other functions of TNC in cancer and other diseases.

Antibody-mediated delivery of interleukin-2 to the stroma of breast cancer strongly enhances the potency of chemotherapy.

PURPOSE: There is an interest in the discovery of biopharmaceuticals, which are well tolerated and which potentiate the action of anthracyclines and taxanes in breast cancer therapy. EXPERIMENTAL DESIGN: We have produced a recombinant fusion protein, composed of the human antibody fragment scFv(F16) fused to human interleukin-2 (F16-IL2), and tested its therapeutic performance in the MDA-MB-231 xenograft model of human breast cancer. The F16 antibody is specific to the alternatively spliced A1 domain of tenascin-C, which is virtually undetectable in normal tissues but is strongly expressed in the neovasculature and stroma of breast cancer. RESULTS: When used as monotherapy, F16-IL2 displayed a strikingly superior therapeutic benefit compared with unconjugated recombinant IL-2. The administration of doxorubicin either before (8 days, 24 h, or 2 h) or simultaneously with the injection of F16-IL2 did not decrease the accumulation of immunocytokine in the tumor as measured by quantitative biodistribution analysis. Therapy experiments, featuring five once per week coadministrations of 20 mug F16-IL2 and doxorubicin, showed a statistically significant reduction of tumor growth rate and prolongation of survival at a 4 mg/kg doxorubicin dose but not at a 1 mg/kg dose. By contrast, combination of F16-IL2 with paclitaxel (5 and 1 mg/kg) exhibited a significant therapeutic benefit compared with paclitaxel alone at both dose levels. F16-IL2, alone or in combination with doxorubicin, was well tolerated in cynomolgus monkeys at doses equivalent to the ones now used in clinical studies. CONCLUSIONS: F16-IL2 may represent a new useful biopharmaceutical for the treatment of breast cancer.

Tenascin-C Prevents Articular Cartilage Degeneration in Murine Osteoarthritis Models.

Objective The objective of this study was to determine whether intra-articular injections of tenascin-C (TNC) could prevent cartilage damage in murine models of osteoarthritis (OA). Design Fluorescently labeled TNC was injected into knee joints and its distribution was examined at 1 day, 4 days, 1 week, 2 weeks, and 4 weeks postinjection. To investigate the effects of TNC on cartilage degeneration after surgery to knee joints, articular spaces were filled with 100 µg/mL (group I), 10 µg/mL (group II) of TNC solution, or control (group III). TNC solution of 10 µg/mL was additionally injected twice after 3 weeks (group IV) or weekly after 1 week, 2 weeks, and 3 weeks (group V). Joint tissues were histologically assessed using the Mankin score and the modified Chambers system at 2 to 8 weeks after surgery. Results Exogenous TNC was maintained in the cartilage and synovium for 1 week after administration. Histological scores in groups I and II were better than scores in group III at 4 and 6 weeks, but progressive cartilage damage was seen in all groups 8 weeks postoperatively. Sequential TNC injections (groups IV and V) showed significantly better Mankin score than single injection (group II) at 8 weeks. Conclusion TNC administered exogenously remained in the cartilage of knee joints for 1 week, and could decelerate articular cartilage degeneration in murine models of OA. We also showed that sequential administration of TNC was more effective than a single injection. TNC could be an important molecule for prevention of articular cartilage damage.

Tenascin-C Orchestrates Glioblastoma Angiogenesis by Modulation of Pro- and Anti-angiogenic Signaling.

High expression of the extracellular matrix component tenascin-C in the tumor microenvironment correlates with decreased patient survival. Tenascin-C promotes cancer progression and a disrupted tumor vasculature through an unclear mechanism. Here, we examine the angiomodulatory role of tenascin-C. We find that direct contact of endothelial cells with tenascin-C disrupts actin polymerization, resulting in cytoplasmic retention of the transcriptional coactivator YAP. Tenascin-C also downregulates YAP pro-angiogenic target genes, thus reducing endothelial cell survival, proliferation, and tubulogenesis. Glioblastoma cells exposed to tenascin-C secrete pro-angiogenic factors that promote endothelial cell survival and tubulogenesis. Proteomic analysis of their secretome reveals a signature, including ephrin-B2, that predicts decreased survival of glioma patients. We find that ephrin-B2 is an important pro-angiogenic tenascin-C effector. Thus, we demonstrate dual activities for tenascin-C in glioblastoma angiogenesis and uncover potential targeting and prediction opportunities.

Epidermal growth factor-like repeats of tenascin-C-induced constriction of cerebral arteries via activation of epidermal growth factor receptors in rats.

Tenascin-C (TNC), one of matricellular proteins, has been suggested to be involved in cerebral vasospasm after aneurysmal subarachnoid hemorrhage. However, the mechanisms of how TNC constricts cerebral arteries remain unclear. The aim of this study was to examine if epidermal growth factor (EGF)-like repeats of TNC is involved in TNC-induced constriction of cerebral arteries in rats via EGF receptor (EGFR) activation. Two dosages of recombinant TNC (r-TNC) consisting of the EGF-like repeats was administered intracisternally to healthy rats, and its vasoconstrictor effects were evaluated by neurobehavioral tests and India-ink angiography at 24, 48, and 72 hours after the administration. Western blotting and immunohistochemistry were performed to explore the underlying mechanisms on constricted cerebral arteries after 24 hours. The effects of a selective EGFR tyrosine kinase inhibitor (AG1478) on r-TNC-induced vasoconstriction were evaluated by neurobehavioral tests, India-ink angiography and immunohistochemistry at 24 hours after the administration. A higher dosage of r-TNC induced cerebral arterial constriction more severely, which continued for 48 hours. The effects were associated with the activation of EGFR and extracellular signal-regulated kinase (ERK)1/2 in the smooth muscle cell layer of the constricted cerebral artery, while c-Jun N-terminal kinase and p38 were not activated. AG1478 blocked r-TNC-induced vasoconstrictive effects, as well as activation of EGFR and ERK1/2. These findings demonstrate that TNC induces constriction of cerebral arteries via activation of EGFR and ERK1/2.

Tenascin-C-coated platinum coils for acceleration of organization of cavities and reduction of lumen size in a rat aneurysm model.

OBJECT: Detachable platinum coils are widely used in the endovascular treatment of intracranial aneurysms. The use of coil placement produces a higher incidence of aneurysm recurrence compared with surgical clipping. To reduce the incidence of recurrence by promoting clot organization, the authors designed a platinum coil coated with tenascin-C (TNC), an extracellular matrix glycoprotein, and then histologically examined tissue responses. METHODS: Platinum coils were prepared by successive coatings with cationic polyethyleneimine and anionic heparin and then TNC or basic fibroblast growth factor (bFGF) was immobilized by affinity binding to the heparin. Six unmodified, six heparin-coated, six bFGF-coated, or eight TNC-coated platinum coils were inserted into ligated common carotid arteries (CCAs) of adult male rats, and CCA segments were harvested after 14 or 28 days. The percentages of organized areas occupying the luminal cavity in unmodified, heparin-coated, bFGF-coated, and TNC-coated groups were 4.8 +/- 4.6, 1.6 +/- 1.1, 17.9 +/- 10.7, and 93.4 +/- 6.9%, respectively. In addition, the mean lumen size in the TNC-coated group (0.35 +/- 0.23 mm2) was reduced to less than half that of the unmodified group (0.72 +/- 0.21 mm2). Immunohistochemical analysis revealed that alpha-smooth muscle actin-positive cells were a major cellular component of the organized tissue within the TNC-coated coils but not in the bFGF group. Collagen fibrils in the organized areas were also much thicker and denser with TNC-coated coils than with bFGF-coated coils. CONCLUSIONS: Placement of TNC-coated coils can remarkably accelerate organization of luminal cavities and reduce their volume, providing improved efficacy of these coils for endovascular embolization.

[Evaluation of surgical complications connected with intraperitoneal chemotherapy in ovarian cancer]. / Analiza powiklan chirurgicznych wystepujacych w przebiegu chemioterapii dootrzewnowej u chorych na raka jajnika.

OBJECTIVES: From a theoretical viewpoint, the use of intraperitoneal therapy (i.p.) in patients with ovarian cancer (a malignancy, which remains mainly confined to the peritoneal cavity) is logical. Intraperitoneal catheters have moved to the forefront as a delivery system in cancer treatment. Authors described complications during the placement, usage, and evacuation of Tenckhoff catheters. Some of them report much too high number of surgery complications connected with i.p. DESIGN: We report a number of complications connected with insertions, functions, and evacuations of Tenckhoffa catheter. MATERIAL AND METHODS: From January 1996 to January 2002, 92 patients with recurrent or persistent ovarian cancer, after surgery and first line chemotherapy, have had catheter insertion performed, but only 79 have had performed catheter evacuation: because of: not complete therapy (7 patients), three patients died during i.p. therapy, in three cases intraperitoneal catheter has spontaneously fold out. RESULTS: During insertion total number of complications 9(9.78%), 6 bowel incision, 1 bladder incision, 1 hernia of the linea alba, 1 incision of bowel and bladder. During catheter evacuation total number of complications 9 (11.39%), 8 bowel incisions 1 hernia of the linea alba. Complications connected with catheter function: only 8 of 92 (8.70%) required cessation of chemotherapy prior to its expected completion, 2 fistula of the catheter to vagina, 2 fistulas to bowel, in two cases intraperitoneal catheter has spontaneously fold out due to abscess, one after citostatics flow under the skin, one because of abscess in peritoneal cavity, and problems with citostatics inflow one because of subileus. CONCLUSION: The surgical complications occurring during IPC are not dangerous for patients. IPC is valid and safe way of treatment patients with ovarian cancer. The frequency of complications occurring during insertion of Tenckhoff catheter depends on the way of placement.

Gellan sulfate core platinum coil with tenascin-C promotes intra-aneurysmal organization in rats.

The aims of this study were to develop a new coil, gellan sulfate core platinum coil (GSCC), that delivers tenascin-C (TNC) to an aneurysm (GSCC-TNC) and to evaluate the effects on intra-aneurysmal organization. We performed in vitro adsorption tests of TNC to gellan sulfate (GS). GSCC-TNC was produced by immersing GSCC in TNC solution under the following conditions (TNC concentration 10, 50, or 100 µg/mL; TNC immersion time 15, 30, or 60 min) by monitoring intra-aneurysmal organization in a rat blind-ended aneurysm model. In addition, 20 rats randomly underwent implantation of a platinum coil or the GSCC-TNC produced under optimum conditions into an aneurysm, whose organization effects were compared in a blind fashion at 2 weeks post-surgery. GS demonstrated a high affinity to TNC in a dose-dependent fashion (affinity constant = 1.79 × 10(10) (M(-1))). GSCC immersed in 10 µg/mL of TNC solution for 30 and 60 min induced similar and better organization of aneurysmal cavity compared with that for 15 min (the ratio of the organized areas in an aneurysmal cavity-15 min, 27.2 ± 11.8 %; 30 min, 75.6 ± 11.9 %; 60 min, 82.6 ± 19.7 %, respectively) with the preservation of the aneurysmal wall structure, while higher TNC concentrations caused the destruction of the aneurysmal wall. GSCC-TNC produced under 10 µg/mL of TNC solution for 30 min showed a significantly better organization of aneurysms compared with bare platinum coils in rats. A newly developed coil, GSCC-TNC, may be effective for improving intra-aneurysmal organization after coil embolization.

Tenfibgen ligand nanoencapsulation delivers bi-functional anti-CK2 RNAi oligomer to key sites for prostate cancer targeting using human xenograft tumors in mice.

Protected and specific delivery of nucleic acids to malignant cells remains a highly desirable approach for cancer therapy. Here we present data on the physical and chemical characteristics, mechanism of action, and pilot therapeutic efficacy of a tenfibgen (TBG)-shell nanocapsule technology for tumor-directed delivery of single stranded DNA/RNA chimeric oligomers targeting CK2αα' to xenograft tumors in mice. The sub-50 nm size TBG nanocapsule (s50-TBG) is a slightly negatively charged, uniform particle of 15 - 20 nm size which confers protection to the nucleic acid cargo. The DNA/RNA chimeric oligomer (RNAi-CK2) functions to decrease CK2αα' expression levels via both siRNA and antisense mechanisms. Systemic delivery of s50-TBG-RNAi-CK2 specifically targets malignant cells, including tumor cells in bone, and at low doses reduces size and CK2-related signals in orthotopic primary and metastatic xenograft prostate cancer tumors. In conclusion, the s50-TBG nanoencapsulation technology together with the chimeric oligomer targeting CK2αα' offer significant promise for systemic treatment of prostate malignancy.

Teneurin C-terminal associated peptide (TCAP)-1 modulates dendritic morphology in hippocampal neurons and decreases anxiety-like behaviors in rats.

Teneurin C-terminal associated peptide (TCAP)-1 is a member of a novel family of neuropeptides that has been highly conserved throughout evolution. TCAP-1 is expressed in the limbic system in areas such as the hippocampus and amygdala. In vitro, TCAP-1 increases cytoskeletal proteins in immortalized neurons and modulates neurite outgrowth in cultured primary hippocampal neurons. In vivo, TCAP-1 blocks stress-induced c-Fos in the hippocampus and amygdala, and modulates stress-induced anxiety-like behaviors. This suggests that TCAP-1 plays a role in the remodeling of limbic system networks to alter stress behaviors. Dendritic spines on the apical and basilar shafts of hippocampal neurons are sensitive to stress and many receive incoming excitatory synaptic connections. In this study, repeated daily injection of TCAP-1 for 10 days increased spine density in the CA1 and CA3 regions of the hippocampus without affecting spine density in the amygdala. Further investigation of the CA3 region indicated that TCAP-1 did not affect the morphology of apical dendrites, but decreased branching in the basilar dendrites 90-130 µm away from the soma. Moreover, TCAP-1 treatment increased open arm time and decreased closed arm entries on the elevated plus maze, a test of anxiety-like behavior. These results suggest that TCAP-1 may be associated with anxiety-like behavior via regulation of dendritic morphology in the hippocampus, independent of amygdalar modification.