Molecular biology in diagnostic histopathology: Part II — cell adhesion molecules

Cardiac gene activation varies between young and adult cats and in the presence of hypertrophic cardiomyopathy

Little is known about the difference of myocardial gene transcription in young and adult cats and how transcription is further modified in cats with hypertrophic cardiomyopathy (HCM) and with left atrial (LA) thrombus formation. We hypothesized that selected factors for coagulation, endothelial activation, inflammation, and remodelling are modified with age and are activated in the hearts of cats with HCM. Left atrial and ventricular (LV) samples from 12 cats with HCM (seven without (HCMwoAT] and five with LA thrombi [HCMwAT]), and six young (YC) and six adult (AC) control cats without cardiac disease were investigated for relative expression of the following genes using quantitative polymerase chain reaction: von Willebrand factor, a disintegrin and metalloproteinase with a thrombospondin type 1 motif member 13, platelet activating factor, E- and P-selectin, intercellular and vascular adhesion molecules-1, ß2-integrin, vascular endothelial growth factor, interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), heat shock protein-70, and myocyte-specific enhancer factor 2C. Significant differences in gene activation were found between YC and AC, and YC and cats with HCM. Compared to AC, MCP-1 and IL-6 were significantly higher in cats with HCM. The presence of an LA thrombus was associated with higher IL-6 expression. These results illustrate the relevance of age and/or lifestyle on gene expression in the feline heart. The gene transcription pattern found in AC hearts might predispose cats to their characteristic cardiac remodelling processes and thrombus formation if disease occurs. It further supports the involvement of inflammation, but not coagulation and endothelial activation, in HCM.

Additive effect of RGD coating to functionalized titanium surfaces on human osteoprogenitor cell adhesion and spreading

Titanium-based biomaterials for endosseous implants have found widespread applications in the orthopedic, maxillofacial, and dental domains. Indeed, the surface characteristics such as their chemical modification control considerably the cellular response and, subsequently, the quality and the quantity of new-formed bone around the implant. In this study, human osteoprogenitor (HOP) cell adhesion on different titanium surfaces functionalized with hydroxyapatite (HA), type I collagen, or Arg-Gly-Asp (RGD)-containing peptides is investigated by the quartz crystal resonators and by confocal laser scanning microscopy (CLSM) for the imaging of focal contact formation. Data obtained by quartz crystal resonator technique revealed that RGD-containing peptides alone increase HOP cell adhesion in early time period of culture. Moreover, association of RGD-containing peptides with either type I collagen or with HA layers induces an additive effect on HOP cell adhesion compared to Ti-Coll or Ti-HA. CLSM shows both the area of focal contact by cell unit and the cytoskeleton network organization to differ according to the surfaces. Interestingly, association of RGD-containing peptides with HA layers induces an additive effect on focal contact formation on HOP cells compared to Ti-HA alone. These data confirm that an RGD peptide effect occurs in the early time of culture, which is beneficial for osteoblast to spreading, differentiation, and survival.

Expression of E-cadherin, cadherin-11, α-, β- and γ-catenins in nephroblastomas: relationship with clinicopathological parameters, prognostic factors and outcome

AIM

This study was undertaken to determine the expression of cell adhesion molecules E-cadherin, cadherin-11, and alpha-, beta- and gamma-catenins in nephroblastomas and to correlate this expression with pathological features and known prognostic factors.

METHODS

Immunohistochemistry was performed on 140 cases of nephroblastoma following heat-induced epitope retrieval and using the streptavidin-biotin technique.

RESULTS

E-cadherin was expressed in 75 cases (54%), cadherin-11 in 128 cases (91%), alpha-catenin in 93 cases (66%), beta-catenin in 133 cases (95%) and gamma-catenin in 22 cases (16%). Nuclear localisation of beta-catenin was not demonstrated. There was a statistically significant relationship between the administration of preoperative chemotherapy and the expression of E-cadherin, alpha- and gamma-catenin, respectively. These proteins were more frequently expressed in tumours treated with preoperative chemotherapy. Those tumours that expressed all four proteins (E-cadherin, alpha-, beta- and gamma-catenin) showed a statistically significant association with the administration of preoperative chemotherapy, in contrast to tumours that did not express all four proteins.

CONCLUSION

Nephroblastomas show a heterogeneous distribution of staining for E-cadherin, cadherin-11, alpha-, beta- and gamma-catenins. Tumours treated with preoperative chemotherapy are more likely to express these molecules. The expression status of E-cadherin, cadherin-11 and the catenins in this cohort does not appear to be of prognostic value.