Immunohistochemical expression of vascular endothelial growth factor (VEGF) in different types of odontogenic cysts

Expression of BMP4 and FOXN1 in orthokeratinized odontogenic cyst compared to odontogenic keratocyst suggests an epidermal phenotype

Odontogenic keratocysts (OKC) and orthokeratinized odontogenic cysts (OOC) are odontogenic cysts that share histological and immunohistochemical similarity with epidermal appendages and cutaneous cystic lesions despite exhibiting contrasting biological behavior. In epidermal appendages, BMP4 induces expression of FOXN1, which participates in terminal differentiation of keratinocytes and control of proliferation. We compared BMP4 and FOXN1 expression in OOC and OKC to investigate their role in the epithelial differentiation of these cysts. BMP4 and FOXN1 expression was assessed using immunohistochemistry in 20 primary sporadic OKC and compared to 16 OOC. BMP4 epithelial expression was detected in 81.25% OOC compared to 35% in OKC, while its expression in connective tissue was observed in 65% OKC and 75% OOC. FOXN1 was detected in 75% OOC vs. 30% OKC. The "triple positive" phenotype, i.e., BMP4 epithelial and connective tissue positivity and FOXN1 epithelial positivity, was seen in 56.25% OOC compared to 10% OKC. The greater expression of BMP4 and FOXN1 in OOC suggests greater activation of this pathway in OOC, which suggests a role in its more mature epithelium; it also resembles an epidermal phenotype.

Assessment of Tumor Angiogenesis by Expression of CD 105 in Ameloblastoma, Odontogenic Keratocyst and Central Giant Cell Lesion

Background:

Angiogenesis is critical for tumor growth and reflects the aggressive behavior of invasive odontogenic lesions [like amelogenesis (AM) (AM), Odontogenic Keratocyst (OKC) and Central giant cell lesion (CGCL)]. Mean vascular density (MVD) shows the angiogenic potential and CD105 is an ideal endothelial biomarker due to its specificity to new blood vessels for MVD detection. The aim of the study was to compare the MVD (angiogenic potential) among AM, OKC and CGCL in comparison to Pyogenic Granuloma (PG) using CD105 biomarker.

Methods:

Sixty-four primary cases of odontogenic invasive tumors (AM, OKC and CGCL) and PG, diagnosed clinically and histologically were included in the study, with 16 samples in each group. Tissue samples of peripheral AM, Peripheral GCL of jaws, malignant AM, and specimen with insufficient tissue were excluded. Tissue sections were embedded, processed and stained using Hematoxylin and Eosin (H and E). Immunohistochemistry was performed using antibodies against CD105, with positive brown cytoplasmic staining in the endothelial cells of neo-vasculature. Distinct countable, positively stained endothelial cell or clusters were evaluated under light microscope for identification of MVD. ANOVA and t-test were applied for statistical analysis of data.

Results:

Highest MVD was displayed in CGCL (32.99±0.77) and the minimum was observed in OKC (7.21± 0.75) respectively. CGCL showed significantly higher MVD to AM, OKC and PG lesions (p<0.05). AM (8.07± 0.36) and Odontogenic Keratocyst (7.21± 0.75) showed comparable MVD, which was lower than PG (14.7± 0.96) and CGCL vascular density (p < 0.01) respectively.

Conclusion:

CGCL was most aggressive, with highest MVD among the investigated odontogenic lesions (OKC, AM and PG). The proliferative aggressive behavior of Odontogenic Keratocyst is comparable to AM due to comparable mean vascular density.

Expression of Vascular Endothelial Growth Factor in Odontogenic Cysts: Is There Any Impression on Clinical Outcome?

Background:

The recent scientific reports have shown that angiogenesis can affect biological behavior of pathologic lesions.

Objective:

Regarding unique clinical outcome of Odontogenic keratocyst (OKC), the present study was aimed to compare angiogenesis in Odontogenic keratocyst and Dentigerous cyst (DC).

Method:

In this experimental study, tissue sections of 46 samples of OKC and DC were stained through immunohistochemical method using Vascular Endothelial Growth Factor (VEGF) antibody. VEGF expression was evaluated in epithelial cells, fibroblasts and endothelial cells. The average percentage of stained cells in any samples was categorized to 3 groups as follows: SCORE 0: 10% of cells or less are positive. SCORE 1: 10 to 50% of cells are positive. SCORE 2: more than 50% of cells are positive. Mann-U-Whitney, T-test and chi-square was used for statistical analysis.

Result:

The average of VEGF expression in 24 samples of DC was 20.2% and in 22 samples of OKC was 52.6%, respectively. The average of VEGF expression in these two cysts had statistical significant differences. (PV= 0.045). There was significant statistical differences between two cysts in the terms of VEGF SCORE (PV= 0.000). OKC samples had significantly higher SCORE for the purpose of VEGF incidence than DC. Also, there were no differences between VEGF expression in epithelial cells of two cysts (PV= 0.268) there were significant statistical differences between two cysts in terms of endothelial cell staining. The endothelial cell staining was significantly higher in OKC than DC (PV= 0.037%).

Conclusion:

Regarding higher expression of Vascular Endothelial Growth factor in OKC than DC, it seems that angiogenesis may have great impression on clinical outcome of OKC.

The role of vascular endothelial growth factor in proliferation of odontogenic cysts and tumors: An immunohistochemical study

Background:

Vascular endothelial growth factor (VEGF) is capable of initiating angiogenesis in blood vessels and may act as mitogenic agent for epithelium of odontogenic cysts and tumors. This study was conducted to evaluate the role of epithelial VEGF expression in odontogenic cysts and ameloblastoma and its correlation with argyrophilic nucleolar organizer region counts to assess its role in their biological behavior.

Materials and Methods:

In this retrospective cross-sectional study, 45 histologically confirmed cases, 15 cases of each of keratocystic odontogenic tumors (KCOTs), dentigerous cysts, and ameloblastomas were examined for immunohistochemical expression for epithelial VEGF, and argyrophilic nucleolar organizer regions (AgNORs) (used as secondary marker in this study) staining was done for comparing the proliferative capacity with VEGF.

Results:

KCOT shows mild expression within the basal layers and strong expression in the suprabasal layer whereas, in dentigerous cysts, a majority showed no VEGF expression whereas ameloblastomas showed strong expression in all cases by stellate reticulum-like cells at the center of the follicles and suprabasal layers of epithelium. The results of AgNOR counts were higher in KCOTs as compared to ameloblastoma and least in dentigerous cysts.

Conclusion:

VEGF expression by the epithelium of odontogenic cysts and tumors may play a role in epithelial proliferation via autocrine mechanism as reflected by increased AgNOR counts. The angiogenic activity via paracrine pathway may be responsible for the difference in growth rate and neoplastic behavior of the lesions.

Immunohistochemical expression of vascular endothelial growth factor in keratocystic odontogenic tumor, dentigerous cyst, and radicular cyst: A comparative study

Background:

Cyst and tumors arise from tissue remains of odontogenesis, these interactions have been considered to play an important role in the tumorigenesis of odontogenic lesions. The connective tissue stroma has an essential role in the preservation of epithelial tissues and minor alterations in the epithelium are followed by corresponding changes in the stroma, such as angiogenesis. Vascular endothelial growth factor (VEGF) is considered the first factor which maintains its position as the most critical driver of vascular formation and is required to initiate the formation of immature vessels, with this aim, present study was executed to evaluate VEGF expression in kertocystic odontogenic tumor, dentigerous cyst and radicular cyst (RC).

Materials and Methods:

A retrospective study was carried out comprising a total of 31 cases; 13 cases of keratocystic odontogenic tumor (KCOT), nine cases of dentigerous cyst (DC) and nine cases of RC. The sections were stained immunohistochemically with VEGF antibody and were evaluated for the presence and intensity of the immuno reactive cells. Statistical analysis was carried out using Chi-square test to inter-compare the VEGF expression between KCOT, DC, and RC.

Results:

VEGF expression in the epithelium and connective tissue was significantly higher in KCOT compared to dentigerous and RC. One case of KCOT with carcinomatous change also revealed positive results for the VEGF expression in the dysplastic epithelium, tumor islands, and connective tissue. The significant difference was observed on inter-comparison of the VEGF expression in the connective tissue of KCOT and DC, whereas no significant difference was observed in the VEGF expression in the connective tissue of KCOT and DC.

Conclusion:

The present study data supports the literature finding that angiogenesis can be important in the progression and enlargement of odontogenic cysts similarly to what occurs in neoplastic conditions and further it can be concluded that the higher positivity for VEGF of KCOT could help to explain in part the aggressive biological behavior of the lesion. The stroma of KCOT could be regarded not only as a structural support of the cyst wall but also as playing a part in the neoplastic behavior of cyst.

VEGF and VEGFR2 in dentigerous cysts associated with impacted third molars

The aims of this study were to determine the presence and distribution of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor-2 (VEGFR2) in dentigerous cysts compared with normal dental follicles as a control tissue and to evaluate endothelial cells and proliferating cells as indicators of angiogenic activity in these tissues.Twenty specimens histologically diagnosed as dentigerous cysts and 20 dental follicle specimens were included. Immunohistochemistry (IHC) using anti-VEGF and anti-VEGFR2 antibodies stained for the growth factor and its receptor, while anti-CD34 and anti-CD146 antibodies were used to identify endothelial cells. Anti-proliferating cell nuclear antigen (PCNA) antibody detected proliferating cells within the specimens. Slides were examined microscopically and results evaluated using kappa statistics, negative binomial regression and ordinal logistic regression.The mean age for patients with dentigerous cysts was 23 years and they were more common in males. Proteins for VEGF, VEGFR2, PCNA, CD34, and CD146 were expressed in all dentigerous cysts and dental follicles. VEGF and VEGFR2 were expressed on several cell types within the tissues, however there was a significantly greater percentage of positive staining in dentigerous cysts compared with dental follicles (odds ratio = 31.24, p < 0.001). CD34(+), CD146(+), and PCNA(+) cells were observed in both dentigerous cysts and dental follicles but for all markers there were significantly more positive cells in dentigerous cysts (p < 0.001); this was especially evident in cases associated with inflammation. PCNA was seen in most endothelial cells lining small thin walled blood vessels suggesting endothelial proliferation. There was a high level of intra- and inter-examiner agreement (kappa 0.77 and 0.75, respectively).VEGF and VEGFR2 and angiogenic activity are present in dental follicles and dentigerous cysts and may contribute to local bone resorption for tooth eruption or the development and progression of dentigerous cysts.

Immunohistochemical expression of vascular endothelial growth factor in orofacial lesions - A review

Angiogenesis is considered to be an important biological process in disease progression and tumorigenesis. Among the various factors associated with angiogenesis, vascular endothelial growth factor (VEGF) is a leading candidate. VEGF induces the proliferation, differentiation, and migration of vascular endothelial cells, increases capillary permeability, and enhances endothelial cell survival by preventing apoptosis. This article reviews and highlights the role of VEGF in health, and various oral diseases.

In vitro systems toxicology approach to investigate the effects of repeated cigarette smoke exposure on human buccal and gingival organotypic epithelial tissue cultures

Smoking has been associated with diseases of the lung, pulmonary airways and oral cavity. Cytologic, genomic and transcriptomic changes in oral mucosa correlate with oral pre-neoplasia, cancer and inflammation (e.g. periodontitis). Alteration of smoking-related gene expression changes in oral epithelial cells is similar to that in bronchial and nasal epithelial cells. Using a systems toxicology approach, we have previously assessed the impact of cigarette smoke (CS) seen as perturbations of biological processes in human nasal and bronchial organotypic epithelial culture models. Here, we report our further assessment using in vitro human oral organotypic epithelium models. We exposed the buccal and gingival organotypic epithelial tissue cultures to CS at the air-liquid interface. CS exposure was associated with increased secretion of inflammatory mediators, induction of cytochrome P450s activity and overall weak toxicity in both tissues. Using microarray technology, gene-set analysis and a novel computational modeling approach leveraging causal biological network models, we identified CS impact on xenobiotic metabolism-related pathways accompanied by a more subtle alteration in inflammatory processes. Gene-set analysis further indicated that the CS-induced pathways in the in vitro buccal tissue models resembled those in the in vivo buccal biopsies of smokers from a published dataset. These findings support the translatability of systems responses from in vitro to in vivo and demonstrate the applicability of oral organotypical tissue models for an impact assessment of CS on various tissues exposed during smoking, as well as for impact assessment of reduced-risk products.