Immunohistochemical expression of E-cadherin, N-cadherin and Snail/slug in ameloblastoma

CONTEXT

Ameloblastoma is the most common odontogenic tumour and its histomorphological distinction into growth patterns and variants, does not accurately convey information about its biologic aggressiveness. Expression of epithelial mesenchymal transition (EMT) markers, which have been implicated in its etiogenesis, might assist in delineating aggressiveness across variants. This may help in formulating appropriate treatment modalities for its management AIMS: To determine expression of SNAIL/SLUG and ECAD/NCAD in tumour cells in clinical and histological subtypes of ameloblastoma and to establish any association between the immunostaining profile and the biologic behaviour of histologic types of ameloblastoma.

SETTINGS/DESIGN

This is a retrospective study conducted to evaluate the immunoprofile of selected clinical subtypes and histological variants to EMT factors via immunostaining to SLUG and ECAD/NCAD antibodies. Mean aggregate scores for each antibody per variant was analyzed using ANOVA or Kruskal-Wallis test when appropriate. Agreement between AR and SR regions was correlated using Spearman's correlation co-efficient.

RESULTS

A higher staining SLUG intensity in the stellate reticulum (SR) like areas relative to the ameloblast like areas (AR) was observed, without concomitant E-cadherin repression or elimination. However, a direct relationship between SLUG and N-cadherin was observed.

CONCLUSION

Expression of SLUG in the SR like areas can be utilized to predict the biologic behavior of specific clinico-histological variants, however its mechanism via alterations in cadherin switching is equivocal.

Neural Cadherin Plays Distinct Roles for Neuronal Survival and Axon Growth under Different Regenerative Conditions

Growing axons in the CNS often migrate along specific pathways to reach their targets. During embryonic development, this migration is guided by different types of cell adhesion molecules (CAMs) present on the surface of glial cells or other neurons, including the neural cadherin (NCAD). Axons in the adult CNS can be stimulated to regenerate, and travel long distances. Crucially, however, while a few axons are guided effectively through the injured nerve under certain conditions, most axons never migrate properly. The molecular underpinnings of the variable growth, and the glial CAMs that are responsible for CNS axon regeneration remain unclear. Here we used optic nerve crush to demonstrate that NCAD plays multifaceted functions in facilitating CNS axon regeneration. Astrocyte-specific deletion of NCAD dramatically decreases regeneration induced by phosphatase and tensin homolog (PTEN) ablation in retinal ganglion cells (RGCs). Consistent with NCAD’s tendency to act as homodimers, deletion of NCAD in RGCs also reduces regeneration. Deletion of NCAD in astrocytes neither alters RGCs’ mammalian target of rapamycin complex 1 (mTORC1) activity nor lesion size, two factors known to affect regeneration. Unexpectedly, however, we find that NCAD deletion in RGCs reduces PTEN-deletion-induced RGC survival. We further show that NCAD deletion, in either astrocytes or RGCs, has negligible effects on the regeneration induced by ciliary neurotrophic factor (CNTF), suggesting that other CAMs are critical under this regenerative condition. Consistent with this notion, CNTF induces expression various integrins known to mediate cell adhesion. Together, our study reveals multilayered functions of NCAD and a molecular basis of variability in guided axon growth.

Non-compressible arterial disease and the risk of coronary calcification in type-2 diabetes

OBJECTIVE

Ankle-brachial index (ABI) screening is recommended for the detection of asymptomatic peripheral arterial disease (PAD) in at-risk populations, including diabetics. A low ABI identifies obstructive lower extremity vascular disease and predicts CVD events and increased mortality. A high ABI represents non-compressible arterial disease (NCAD), and is also associated with increased mortality and vascular events. Our objective is to investigate whether low and high ABI have distinct patterns of association with cardiovascular disease (CVD) risk factors and subclinical atherosclerosis in individuals with type-II diabetes mellitus.

METHODS

The Penn Diabetes Heart Study (PDHS) is a prospective observational cohort of diabetic individuals without clinically evident CVD. Multivariate logistic and Tobit linear regression were used to compare CVD risk factors and coronary artery (CAC) among 1863 subjects with PAD (ABI ≤ 0.9), NCAD (ABI ≥ 1.4 or non-compressible) or normal ABI (0.91-1.39).

RESULTS

Compared to those with normal ABI, PAD was associated with smoking, obesity, and lower HDL-c; while diabetes duration and reduced renal function were associated with NCAD. Both PAD and NCAD were independently associated with increased CAC compared to those with normal ABI, and these relationships were not attenuated in multiply adjusted models.

CONCLUSION

NCAD bears a distinct relationship to traditional CVD risk factors among diabetics, though like PAD is independently associated with increased CAC. These findings support the recognition of NCAD as a high-risk phenotype and provide additional relevance to ABI screening in diabetics.