Unconjugated
In order to diagnose death associated with fire, it is essential to show that the person was exposed to heat while still alive. We investigated both AQP1 and AQP3 expression in the skin of an experimental burn model, as well as in forensic autopsy cases, and discuss its role in the differential diagnosis of ante- and postmortem burns. In animal experiments, there was no difference in AQP1 gene expression among four groups (n=4): antemortem burn, postmortem burn, mechanical wound, and control. However, AQP3 expression in the antemortem burn was increased significantly compared with that of the other groups even at 5min after burn. Water content of the skin was decreased significantly by the burn procedure. Consistent with animal experiments, AQP3 gene expression in the skin of antemortem burn cases was increased significantly compared with postmortem burns, mechanical wounds, and controls (n=12 in each group). These observations suggest that dermal AQP3 gene expression was increased to maintain water homeostasis in response to dehydration from burn. Finally, our results suggest that AQP3 gene expression may be useful for forensic molecular diagnosis of antemortem burn.
This study aimed to evaluate the relationship of aquaporin-3 (AQP3) expression with clinico-pathological parameters and lymph node metastasis in patients with oral squamous cell carcinoma (SCC). The immunohistochemical distribution of AQP3 was investigated in normal squamous epithelium and SCC tissue of 48 cases of SCC of the tongue and floor of the mouth. The percentage of the total AQP3-positive SCC tissue area relative to the total tumour tissue area (T-AQP3) was calculated as a morphometric AQP3 parameter for each patient. Furthermore, the percentage of the AQP3-positive area relative to the SCC tissue area at the invasion front (F-AQP3) was calculated as another AQP3 parameter. The immunostaining pattern of AQP3 in SCC tissue was irregular and weaker than that in normal epithelium. Well-differentiated SCCs had higher T-AQP3 and F-AQP3 values than poorly differentiated SCCs. SCCs with an infiltrative invasion pattern had lower F-AQP3 than SCCs with expansive and intermediate patterns. SCCs with T-AQP3 <27% or F-AQP3 <17% showed an increased incidence of lymphatic metastasis, and multivariate analysis demonstrated that F-AQP3 was an independent prognostic factor of lymphatic metastasis. These results suggest that AQP3 is involved in keratinocyte differentiation and decreased AQP3 expression is associated with more aggressive tumour behaviour.