Expression of TP53 and IL-1α in unicystic ameloblastoma predicts the efficacy of marsupialization treatment

In this study, we evaluated the effects of marsupialization in treating unicystic ameloblastoma (UA) and investigated the relationship between TP53 and interleukin 1 α (IL-1α) expression and the clinical outcome of UA treated with marsupialization.Consecutive patients treated with marsupialization and curettage at Shanghai Ninth People's Hospital were included. According to the unified standard, 48 patients were included in this study. Of these, 20 showed a good response, 10 a partial response, and 18 no response, based on the outcome of the marsupialization procedure. The expression of proteins TP53 and IL-1α was detected with immunohistochemistry (IHC). The clinical and pathological characteristics of the patients were analyzed.Analysis of the clinical and pathological characteristics showed that the effects of marsupialization treatment were significantly associated with lesion location (P < .001) and tumor diameter (P = .01). IHC showed that TP53 expression was significantly higher in the good-response group than in the partial- or no-response group (P = .02), and IL-1α expression was significantly higher in the good-response group than in the partial- and no-response groups (P = .03).Marsupialization is an effective preliminary procedure for treating UA before curettage and peripheral ostectomy. The expression of the TP53 and IL-1α proteins correlates directly with the outcome of UA treated with marsupialization.

Influence of surgical decompression on the expression of inflammatory and tissue repair biomarkers in periapical cysts

OBJECTIVE

The biologic effects of surgical decompression on the epithelium and connective tissues of periapical cysts are not fully understood. The aim of this study was to evaluate the expression of tissue repair and inflammatory biomarkers in periapical cysts before and after surgical decompression.

STUDY DESIGN

Nine specimens of periapical cysts treated with decompression before undergoing complete enucleation were immunohistochemically analyzed to investigate the expression of interleukin-1β, tumor necrosis factor-α, transforming growth factor-β1, matrix metalloproteinase-9, Ki-67, and epidermal growth factor receptor. Expression of the biomarkers was classified as positive, focal, or negative. Ki-67 immunoexpression was calculated as a cell proliferation index. The expression of the biomarkers was compared in the specimens from decompression and from the final surgical procedure.

RESULTS

Computed tomography demonstrated that volume was reduced in all cysts after decompression. There were no differences in the immunoexpression of the proinflammatory and tissue repair biomarkers when comparing the specimens obtained before and after the decompression.

CONCLUSIONS

Surgical decompression was efficient in reducing the volume of periapical cysts before complete enucleation. When comparing the specimens obtained from surgical decompression and from complete surgical removal, the immunohistochemical analysis did not show a decrease in proinflammatory biomarkers; neither did it show an increase in tissue repair biomarkers.

Cyclooxygenase-2 expression in keratocystic odontogenic tumour decreased following decompression

Marsupialisation or decompression is frequently performed as a conservative therapy for keratocystic odontogenic tumours (KCOTs). Positive cyclooxygenase-2 (COX-2) expression in the epithelium of KCOTs was recently reported and may be associated with neoplastic invasion and progression. The aim of the present study was to investigate the change in COX-2 expression in the KCOT epithelium following decompression. In this study, 16 pairs of KCOT biopsy specimens obtained during decompression or enucleation were collected and analysed. Formalin-fixed, paraffin-embedded blocks were sectioned and immunohistochemically investigated using anti-COX-2 antibody. The molecular expression was semi-quantitatively evaluated as follows: 0, negative; 1, weakly to moderately positive; and 2, strongly positive. In the samples obtained prior to decompression, the positive staining for COX-2 was immunolocalised to the cell membrane and the cytoplasm, it involved the full thickness of the epithelium and 15 of the 16 specimens (93.8%) exhibited mild to strong positivity. As regards the samples obtained following decompression, only 3 of the 16 specimens (18.8%) exhibited a mild positivity. The expression levels of COX-2 were significantly decreased following decompression (P<0.05). It may be concluded that loss or a significant reduction of COX-2 expression is associated with decompression in KCOTs. However, large-scale studies are required to verify these results and improve our knowledge of the possible involvement of COX-2 in the pathogenic mechanism underlying the development of KCOTs.

A comparative immunohistochemical analysis of COX-2, p53, and Ki-67 expression in keratocystic odontogenic tumors

OBJECTIVE

The aim of the present study was to investigate the association between the expression of cyclooxygenase-2 (COX-2) in keratocystic odontogenic tumors (KCOT) and more commonly used markers, such as p53 and Ki-67.

STUDY DESIGN

Expression of cyclooxygenase-2 (COX-2) in 20 biopsy specimens of keratocystic odontogenic tumors (KCOT) has been analyzed and compared with the expression of previously reported markers Ki-67 and p53. Formalin-fixed, paraffin-embedded blocks were sectioned and used for hematoxylin-eosin (H&E) staining and incubated with anti-cox-2, anti-ki-67, and anti-p53 monoclonal antibodies for immunohistochemical examination. Detection of the COX-2 antibody was performed with the EnVision kit. Cellular staining pattern was cytoplasmatic for COX-2 and nuclear for both Ki-67 and p-53. Molecular expressions were semiquantitatively evaluated as negative (-), mild (±) or strong (+).

RESULTS

Mild to strong expression of COX-2 was observed in 20 (100%) of the cases. Fifteen (75%) of the KCOTs stained positive for p53 and 18 (90%) stained positive for Ki-67. There was no statistically relevant difference between the expressions of COX - 2, Ki-67, and p53.

CONCLUSIONS

Although COX-2 has rarely been used to assess the biological activity of the KCOT, the results portrayed in the current study and the current knowledge of the overall role known to be played by COX-2 in tumorigenesis suggest that COX-2 may be an important marker involved in the biological behavior of the KCOT. Larger studies are required to improve our knowledge of the possible role of COX-2 in the pathogenic mechanism involved in KCOT.