Co-expression of Ki-67 and p53 protein in ameloblastoma and keratocystic odontogenic tumor

Cyst or Tumor? A systematic review and meta-analysis on the expression of p53 marker in Odontogenic Keratocysts

The odontogenic keratocyst (OKC) is a potentially aggressive odontogenic lesion and there is an ongoing debate regarding its biological behavior and classification. The present systematic review aims to assess the expression of the p53 protein in the odontogenic keratocyst in comparison to the dentigerous cyst and ameloblastoma. We searched MEDLINE, Web of Science and Scopus for immunohistochemical studies reporting OKC's, dentigerous cysts and solid/multicystic ameloblastomas. The Risk Difference between the lesions expressing the p53 was the effect measure and a P value < 0.05 was considered to provide evidence to the effect estimates. Results: The first hit retrieved 126 records. After duplicates removal, there were 84 articles, of which eighteen were assessed for eligibility. Thirteen articles were included in the meta-analysis, showing that OKC's have an estimated difference of 23% (P < 0.003) in the probability to express the p53 over dentigerous cysts, and an estimated difference of 4% (P = 0.28) in the probability to express the p53 over ameloblastomas. OKCs seem to behave more similarly to a tumor rather than an odontogenic cyst regarding its p53 expression and the classification of this lesion into Keratocystic Odontogenic Tumor should be carefully revaluated.

Genetic factors in the pathogenesis of ameloblastoma, dentigerous cyst and odontogenic keratocyst

Ameloblastoma (AB), dentigerous cyst (DC) and Odontogenic keratocyst (OKC) are odontogenic lesions with propensity to malignant transformation or local invasion. The molecular mechanisms of development of these lesions are not fully understood. However, some researches have reported dysregulation of tumor suppressor genes or oncogenes in these lesions. Down-regulation of P53 gene has been reported in AB, DC and OKC. Moreover, several long non-coding RNAs such as ENST00000512916 and KIAA0125 have been dysregulated in AB tissues. Single nucleotide polymorphisms within a variety of genes have been associated with certain types of odontogenic lesions. In the current review, we summarize the current data about the expression pattern of genes in these lesions and the observed association between genetic polymorphisms and development of these lesions.

Computerized Evaluation of the Immunoexpression of Ki-67 Protein in Odontogenic Keratocyst and Dentigerous Cyst

Evaluation and comparison of odontogenic keratocysts and detigerous cysts immunoexpression and immunostaining intensities of Ki-67 antigen by assessing the whole extent of the epithelium (all epithelium layers in combination) and each layer individually. Ki-67 immunoexpression was evaluated in 15 odontogenic keratocysts and 6 dentigerous cysts using automated methods and the Aperio Technologies Inc. computer system. No statistically significant differences were observed in immunoexpression nor in immunostaining intensities between both lesions. Also, no statistically significant differences were found between odontogenic keratocysts from maxilla versus mandible nor primary versus recurrent. However, odontogenic keratocyst showed a significantly higher cellular proliferation index in the suprabasal layers compared to the basal layer. Assessment of the cellular proliferation index through a computerized system enabled the evaluation of all epithelial tissue without field selection. The increased Ki-67 immunoexpression in suprabasal layers of odontogenic keratocyst suggests a different biological behavior and more aggressive proliferation potential when compared to dentigerous cyst. The same result was found in recurrent odontogenic keratocysts when compared with primary ones. The odontogenic keratocysts of the maxilla and mandible have similar Ki-67 immunoexpression. The evaluation of cellular proliferation only by immunohistochemical analysis with Ki-67 antigen does not provide enough data to elucidate the biological behavior of odontogenic keratocyst.

Maspin, Syndecan-1, and Ki-67 in the Odontogenic Keratocyst: An Immunohistochemical Analysis

The odontogenic keratocyst (OKC) is a controversial lesion that was reclassified as a tumor with the name “keratocystic odontogenic tumor” in 2005. The reclassification was revoked recently in 2017, with a conclusion on the need for further studies on the subject. In this study, the expressions of an important regulatory protein (maspin), an important integral membrane proteoglycan (syndecan-1), and a universal proliferation marker (Ki-67) in the epithelium of the OKC were investigated in comparison with the dentigerous cyst (DC) and ameloblastoma (AB). Twenty-six OKCs, eleven DCs, and ten conventional ABs were immunohistochemically stained for maspin, syndecan-1, and Ki-67. ImageJ was used to analyze the positivity of maspin and syndecan-1. The Ki-67 score was calculated as the percentage of positive nuclei in 5 high power fields. Analysis of variance (ANOVA) test and Student t-test were used as appropriate. Lower expressions of maspin were noted in OKC and DC compared to those in AB, and lower expressions of syndecan-1 were noted in OKC and AB compared to those in DC. The differences, however, did not reach statistical significance (ANOVA and t-test: P > 0.05). The Ki-67 score was significantly higher in OKC than in DC (t-test: P < 0.05), and not significantly different from AB (t-test: P > 0.05). In conclusion, expressions of maspin and syndecan-1 are not strongly representative of differences in behavior between OKC, AB, and DC. However, the expression of Ki-67 indicates comparable proliferative activities of OKC and AB, which are higher than that of DC. Further investigation on the biologic behavior of OKC is still recommended to arrive at more specific conclusions regarding its classification.

Clinicopathologic study on a rare variant of ameloblastoma with basal cell features

OBJECTIVES

To investigate the clinical features, pathologic manifestations, and biologic behaviors of a variant of ameloblastoma with basal cell features (AM-BC).

MATERIALS AND METHODS

Following retrospective review of the clinical and pathological data of six cases of AM-BC, we described their histological and immunohistochemical (IHC) features and discussed the biologic behaviors, prognoses, pathogenesis, and clinical relevance of AM-BC. Direct sequencing of polymerase chain reaction products was also performed in all cases.

RESULTS

The six cases of AM-BC involved four women and two men, aged 22-82 years. Four lesions occurred in the maxilla and two in the mandible. Histologically, the basal cells tended to be arranged as unequally sized follicles, strands, or cords of odontogenic epithelium in the connective tissue stroma. Little or no stellate reticulum was present in the central portion of the nest. Expression of CKs was consistent with other histological variants of ameloblastoma (AM), but AM-BC had significantly higher p53 and Ki-67 (p < 0.05) labeling indices than other histological variants of AM. Two patients had BRAF gene mutations.

CONCLUSION

Ameloblastoma with basal cell features is a very rare variant of AM. Our study showed the differences and relationships that exist between AM-BC and other variants of AM, which could enhance understanding of AM-BC.

Protein 53, B-Cell Lymphoma-2, Cyclooxygenase-2, and CD105 Reactivity in Keratocystic Odontogenic Tumors: An Immunohistochemical Analysis

OBJECTIVE

The objective is to evaluate and compare immunohistochemically, the biological behavior of keratocystic odontogenic tumor (KCOT) with normal oral mucosa by analyzing cell proliferation, angiogenesis, and antiapoptosis using cyclooxygenase-2 (COX-2), protein 53 (p53), B-cell lymphoma-2 (Bcl-2), and CD105 (endoglin).

MATERIALS AND METHODS

The present study comprised 30 cases of KCOT in the study group, in which the expression of COX-2, p53, Bcl-2, and CD105 were analyzed and compared with that of control group consisting of 30 normal oral mucosae.

RESULTS

The results were evaluated based on a number of positively stained cells; among 30 samples of KCOT, 22 samples were p53 positive, 23 samples were Bcl-2 positive, 18 samples were COX-2 positive, whereas all the above markers were negative in all the 30 samples of the normal oral mucosa and CD105 mean vascular density in KCOT 13.8 in normal oral mucosa.

CONCLUSION

The present study suggests that angiogenesis, cell proliferation, and antiapoptosis may be the possible factors contributing for the unique biological behavior of KCOT.

Regulation of Wnt/β-catenin pathway may be related to Regγ in benign epithelial odontogenic lesions

OBJECTIVES

The aim of this study was to analyze and compare the immunoexpressions of Regγ, Wnt-1, and β-catenin in ameloblastomas, adenomatoid odontogenic tumors (AOTs), and odontogenic keratocysts (OKCs).

STUDY DESIGN

Thirty solid ameloblastomas, 20 AOTs, and 30 OKCs were selected for analysis of the immunoexpression of Regγ, Wnt-1, and β-catenin. Each case was semiquantitatively evaluated in the epithelial component and in their different cellular compartments (membrane, cytoplasm, and nucleus).

RESULTS

Ameloblastomas displayed higher cytoplasmic and nuclear Regγ expression compared with AOTs and OKCs, as well as higher membrane and cytoplasmic Wnt-1 expression (P < .05). β-catenin membrane expression was higher in OKCs compared with ameloblastomas and AOTs (P < .05). Nuclear β-catenin expression was higher in ameloblastomas and AOTs than in OKCs (P < .05). Cytoplasmic and nuclear Regγ expression in AOTs were positively correlated with nuclear β-catenin expression (P < .05).

CONCLUSIONS

The marked expressions of Regγ, Wnt-1, and β-catenin suggest the participation of these proteins in the pathogenesis of the studied lesions. The greater expressions of Regγ, Wnt-1, and nuclear β-catenin in ameloblastomas may be related to their more aggressive behavior. Pro-tumor effects of nuclear β-catenin may be counterbalanced by inhibitory pathways in AOTs, justifying their low aggressiveness.

p53-Family Proteins in Odontogenic Cysts: An Immunohistochemical Study

The present study investigated the immunohistochemical expression of p53, p63, and p73 in different types of odontogenic cysts (OC), a group of common intraosseous jaw lesions, to provide a better understanding of p53-family functions in odontogenic lesions. We carried out immunohistochemical analysis to evaluate the expression of p53, p63, and p73 in 60 samples of OC, including dentigerous cysts, radicular cysts, orthokeratinized OC, and odontogenic keratocysts (OKC). The epithelial expression of p53-family members was evaluated both in the basal-parabasal and in the superficial layers, measuring the percentage of positive cells and the value of expression intensity. The expression of p53-family members showed a significant difference between the "OKC" and "non-OKC" groups. In particular, p53 positivity in the basal-parabasal layers, as well as p63 positivity in the superficial layers, were more common in OKC (P<0.0001; P=0.0237). p73 expression in the superficial layers was significantly more expressed in the "non-OKC" group (P<0.0001). No significant differences of staining intensity scores were reported between the groups. The Spearman test showed a positive correlation between p53 and p73 expression at the basal-parabasal level in all cysts (r=0.6626; P<0.0001). These results showed a significantly different expression of p53-family members in OC groups, in particular between the "OKC" and "non-OKC" groups, suggesting the existence of a p53-family pathway in the epithelial lining of OC.

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.

P53 Protein Expression in Dental Follicle, Dentigerous Cyst, Odontogenic Keratocyst, and Inflammatory Subtypes of Cysts: An Immunohistochemical Study

OBJECTIVES

An odontogenic keratocyst (OKC) is a developmental odontogenic cyst with aggressive clinical behavior. This cyst shows a different growth mechanism from the more common dentigerous cyst and now has been renamed as a keratocystic odontogenic tumor (KCOT). Inflammation can assist tumor growth via different mechanisms including dysregulation of the p53 gene. This study aims to assess and compare the expression of tumor suppressor gene p53 in inflamed and non-inflamed types of OKC and dentigerous cyst.

METHODS

Immunohistochemical expression of p53 was assessed in 14 cases of dental follicle, 34 cases of OKC (including 18 inflamed OKCs), and 31 cases of dentigerous cyst (including 16 inflamed cysts).

RESULTS

The mean percentage of p53 positive cells was 0.7% in dental follicles, 5.4% in non-inflamed OKCs, 17.3% in inflamed OKCs, 1.2% in non-inflamed dentigerous cysts, and 2.2% in inflamed dentigerous cysts. The differences between the groups were statistically significant (p < 0.050) except for the difference between inflamed and non-inflamed dentigerous cysts, and between dental follicle and non-inflamed dentigerous cyst.

CONCLUSIONS

The difference in p53 expression in OKC and dentigerous cyst can explain their different growth mechanism and clinical behavior. Inflammation is responsible for the change in behavior of neoplastic epithelium of OKC via p53 overexpression.

Role of HIF-1α and CASPASE-3 in cystogenesis of odontogenic cysts and tumors

OBJECTIVES

Odontogenic cysts and tumors are the most relevant lesions that affect the gnathic bones. These lesions have in common the formation of cystic areas and this common feature may suggest involvement of similar mechanisms. The hypoxia inducible factor 1 alpha (HIF-1α), a responsive protein to hypoxia and caspase-3, an irreversible apoptosis marker, may contribute to cyst formation. Thus, this study aimed to investigate the immunoexpression of these proteins in odontogenic cysts and tumors.

MATERIAL AND METHODS

Twenty cases of ameloblastoma, keratocystic odontogenic tumor (KOT) (n = 20), radicular cyst (RC) (n = 18), dentigerous cyst (DC) (n = 11), calcifying cystic odontogenic tumor (n = 8), and dental follicle (DF) (n = 10) were used to investigate HIF-1α and caspase-3 expression in sequential serial cuts by immunohistochemistry.

RESULTS

HIF-1α was overexpressed in RC, DC, and ameloblastoma when compared with DF. The basal and sometimes the lower suprabasal layer showed no or very low expression in DC, KOT, and ameloblastoma, the last also showing strong expression in solid epithelial areas and initial cystic formation regions. Caspase-3 was found to be overexpressed in all lesions, with the highest expression in odontogenic cysts compared to tumors. HIF-1α and caspase-3 were localized in similar areas of the same lesions, especially in the epithelium surrounding cystic formations.

CONCLUSIONS

This study showed distinct immunoexpression of HIF-1α and caspase-3 in odontogenic cyst and tumors, with higher expression observed in odontogenic cysts.

CLINICAL RELEVANCE

These findings suggest a possible correlation between hypoxia, apoptosis, and cystogenesis, leading to understand the mechanisms responsible to cystic formation in odontogenic lesions.

Yield of p53 expression in esophageal squamous cell cancer and its relationship with survival

BACKGROUND/AIMS

Esophageal squamous cell carcinoma (ESCC) is the most aggressive type of cancer. Mutation of tumor suppressor gene p53 is observed in many gastrointestinal malignancies including ESCC. The immunohistochemical protein expression of mutant p53 has been proposed as a potential tool to evaluate the biological behavior of ESCC. Predictive value of p53 for survival is debatable, hence this study was formulated to know the survival of patients with p53 expression in ESCC.

PATIENTS AND METHODS

We prospectively included 91 consecutive patients of ESCC from August 2014 to August 2016. Biopsy specimens were treated immunohistochemically and expression of p53 gene was analyzed by Immunoreactive Score (IRS). These findings were then compared with clinicopathological parameters such as age, gender, histological grades, and TNM stages. All patients received treatment and were kept under regular follow-up.

RESULTS

M: F ratio was 2.03:1. p53 expression analyzed by IRS showed low expression (score ≤6) in 35 patients (38.46%) and high expression (>6) in 56 patients (61.54%). Level of p53 expression increased significantly with increasing histological grades of ESCC and TNM stage (P ≤ 0.001). Multivariate analysis shows p53 expression as independent predictor of survival. After 1 year of follow up, survival in the p53 high-expression group was 67.86% [standard error (SE) = 0.0473, confidence interval (CI) = 0.75-0.97) and in low p53 expression group was 91.43% (SE = 0.06, CI = 0.53-0.78) with statistically significant difference P = 0.0001 when analyzed with Kaplan-Meier method.

CONCLUSION

Expression of p53 correlates with the survival and is a simple, effective and reproducible modality to determine the prognosis and survival in ESCC.

Odontogenic epithelial proliferation is correlated with COX-2 expression in dentigerous cyst and ameloblastoma

Investigation of cyclooxygenase (COX)-2 in dentigerous cyst and ameloblastoma may help to improve understanding of the nature and behavior of odontogenic cysts and tumors, and in addition may eventually represent a definitive target for a pharmacological approach in the management of these lesions. The aim of this study was to evaluate COX-2 expression and its correlation with the proliferation of odontogenic epithelium in these lesions. Dentigerous cysts (n=16) and ameloblastomas (n=17) were evaluated. Detection of Ki-67 and COX-2 protein expression was conducted by immunohistochemistry. Data were statistically analyzed using Mann-Whitney U test and Spearman's rank correlation coefficient. No significant differences were found in the expression of Ki-67 and COX-2 between dentigerous cysts and ameloblastomas (P>0.05). A significant positive correlation (P=0.018) and highly significant positive correlation (P=0.004) were found between Ki-67 and COX-2 expression in the odontogenic epithelium of dentigerous cyst and ameloblastoma, respectively. COX-2 was expressed in the odontogenic epithelium of dentigerous cyst and ameloblastoma. It may contribute to local extension of these lesions by increasing the proliferation of their odontogenic epithelial cells.

Evaluation of the Nature of Collagen Fibers in KCOT, Dentigerous Cyst and Ameloblastoma using Picrosirius Red Stain - A Comparative Study

BACKGROUND

Reciprocal interaction between dental epithelium and mesenchyme is thought to be crucial for normal odontogenesis. Thus, the mesenchymal influence of the fibrous capsules may play an important role in the maintenance of epithelial expression. Collagen is the major component of the extracellular matrix and possibly there is an alteration in the nature and structure of collagen in various pathological conditions. Studies by polarizing microscopy have also shown that there is a difference in collagen and probably these differences may play a role in their biologic behaviour.

AIM

The purpose of this study was to evaluate the nature of collagen fibers in keratocystic odontogenic tumour (KCOT), dentigerous cyst (DC), unicystic ameloblastoma (UA) and solid/multicystic ameloblastoma (SMA) and correlating this with their biological behaviour.

MATERIALS AND METHODS

Five diagnosed cases each of UA, SMA, KCOT and DC were taken and stained using Picrosirius red stain kit and evaluated using a polarizing microscope.

STATISTICAL ANALYSIS

Chi-square test was used to analyse the results.

RESULTS AND CONCLUSION

Collagen fibers in dentigerous cysts showed predominant yellowish-red birefringence and fibers in KCOT and ameloblastomas showed a predominantly greenish-yellow birefringence. Hence, our study suggests that the nature and character of collagen fibers may influence the clinical behaviour of the lesion. Since ours is a pilot study, to corroborate our view, studies with larger sample size are required to substantiate the results.

Expansile keratocystic odontogenic tumor in the maxilla: immunohistochemical studies and review of literature

Keratocystic odontogenic tumors (KCOT) - previously termed odontogenic keratocysts (OKC) - are characterized by aggressive behavior and a high rate of recurrence. Histopathologically, the basal layer of KCOT shows a higher cell proliferation rate and increased expression of anti-apoptosis genes. Clinically, KCOT is frequently involved in the mandibular posterior region but is not common in the posterior maxilla. However, it should be noted that due to its expansive characteristics, KCOT involved near the maxillary sinus could easily expand to an enormous size and occupy the entire maxilla. To achieve total excision of these expanded cystic tumors in the maxilla, a more aggressive approach would be needed. In this report, we describe two cases of expansile KCOT involving the entire unilateral maxilla and maxillary sinus; they were completely excised using the Weber-Ferguson approach, showing no evidence of recurrence during the follow-up period of more than two years. In immunohistochemical analyses of the tumor specimens, p53 and p63 showed strong expression, and B-cell lymphoma 2 (BCL2) and MKI67 (Ki-67) showed moderate or weak expression, however, detection of BCL2-associated X protein (BAX) was almost negative. These data indicate that expansile KCOT possesses increased anti-apoptotic activity and cell proliferation rate but decreased apoptosis. These properties of KCOT may contribute to tumor enlargement, aggressive behavior, and high recurrence rate.

Keratocystic odontogenic tumor: a retrospective analysis of genetic, immunohistochemical and therapeutic features. Proposal of a multicenter clinical survey tool

OBJECTIVE

In 2005, the World Health Organization reclassified the parakeratinizing odontogenic keratocyst as a neoplasm. This article reviews the research leading to this reclassification, and validates a new survey tool that can be easily used to pool surgical and recurrence data from multiple offices.

STUDY DESIGN

All odontogenic lesions accessioned in the Iowa Surgical Oral Pathology Laboratory between 1949 and 2010 were identified from the database. A survey tool to assess treatment and follow-up was created. A total of 46 surgeons agreed to participate.

RESULTS

A total of 70 keratocystic odontogenic tumors (KOTs) had documented recurrences at follow-up intervals ranging from 6 months to 5 years. Primary tumors that recurred ranged in size as measured by greatest radiographic diameter from 0.7 to 6 cm.

CONCLUSIONS

This survey tool is recommended as standard allowing treatment of cases by multiple practitioners to be compared retrospectively or prospectively.