Eugenol as a potential adjuvant therapy for gingival squamous cell carcinoma.

Adoption of plant-derived compounds for the management of oral cancer is encouraged by the scientific community due to emerging chemoresistance and conventional treatments adverse effects. Considering that very few studies investigated eugenol clinical relevance for gingival carcinoma, we ought to explore its selectivity and performance according to aggressiveness level. For this purpose, non-oncogenic human oral epithelial cells (GMSM-K) were used together with the Tongue (SCC-9) and Gingival (Ca9-22) squamous cell carcinoma lines to assess key tumorigenesis processes. Overall, eugenol inhibited cell proliferation and colony formation while inducing cytotoxicity in cancer cells as compared to normal counterparts. The recorded effect was greater in gingival carcinoma and appears to be mediated through apoptosis induction and promotion of p21/p27/cyclin D1 modulation and subsequent Ca9-22 cell cycle arrest at the G0/G1 phase, in a p53-independent manner. At these levels, distinct genetic profiles were uncovered for both cell lines by QPCR array. Moreover, it seems that our active component limited Ca9-22 and SCC-9 cell migration respectively through MMP1/3 downregulation and stimulation of inactive MMPs complex formation. Finally, Ca9-22 behaviour appears to be mainly modulated by the P38/STAT5/NFkB pathways. In summary, we can disclose that eugenol is cancer selective and that its mediated anti-cancer mechanisms vary according to the cell line with gingival squamous cell carcinoma being more sensitive to this phytotherapy agent.

Cellular mechanisms mediating the anti-cancer effects of carnosol on gingiva carcinoma.

Carnosol, a rosemary polyphenol, displays anticancer properties and is suggested as a safer alternative to conventional surgery, radiotherapy, and chemotherapy. Given that its effects on gingiva carcinoma have not yet been investigated, the aim of this study was to explore its anti-tumor selectivity and to unravel its underlying mechanisms of action. Hence, oral tongue and gingiva carcinoma cell lines exposed to carnosol were analyzed to estimate cytotoxicity, cell viability, cell proliferation, and colony formation potential as compared with those of normal cells. Key cell cycle and apoptotic markers were also measured. Finally, cell migration, oxidative stress, and crucial cell signaling pathways were assessed. Selective anti-gingiva carcinoma activity was disclosed. Overall, carnosol mediated colony formation and proliferation suppression in addition to cytotoxicity induction. Cell cycle arrest was highlighted by the disruption of the c-myc oncogene/p53 tumor suppressor balance. Carnosol also increased apoptosis, oxidative stress, and antioxidant activity. On a larger scale, the alteration of cell cycle and apoptotic profiles was also demonstrated by QPCR array. This was most likely achieved by controlling the STAT5, ERK1/2, p38, and NF-ĸB signaling pathways. Lastly, carnosol reduced inflammation and invasion ability by modulating IL-6 and MMP9/TIMP-1 axes. This study establishes a robust foundation, urging extensive inquiry both in vivo and in clinical settings, to substantiate the efficacy of carnosol in managing gingiva carcinoma.

SATB2 is frequently expressed in ossifying and non-ossifying peripheral oral fibroma of the gingival region but not in reactive fibromatous lesions from other intraoral sites.

Ossifying and non-ossifying peripheral oral fibromas (POF) of the gingival and alveolar mucosa are localized, cellular, small fibrous nodular lesions likely resulting from diverse external/ internal physical and chemical irritation or injuries. A central nidus of metaplastic woven bone characterizes and defines the ossifying variant. The inherent tendency of these lesions to ossify remains elusive. We herein analyze SATB2 expression as osteoblastic transcription and differentiation factor in 28 gingival POFs (10 of them ossifying) and compare them to 28 fibrous lesions from different non-gingival intraoral sites. Strong to moderate diffuse nuclear SATB2 immunoreactivity was detected in all ossifying (10/10; 100%) and in 8/18 (44%) non-ossifying gingival POFs, but in only 1/28 (3%) non-gingival oral reactive nodular fibrous lesions. This study illustrates for the first-time consistent expression of the osteoblastic marker SATB2 in ossifying and most of non-ossifying POFs of the gingival area but lack of this marker in reactive fibrous lesions from other oral cavity sites. This finding is in line with the proposed origin of gingival POFs from periodontal ligaments and may explain the frequent ossification observed in them. It is mandatory to consider this finding when assessing biopsies from SATB2-positive oral cavity neoplasms to avoid misinterpretation.

ZnO Nanoparticles Induced Caspase-Dependent Apoptosis in Gingival Squamous Cell Carcinoma through Mitochondrial Dysfunction and p70S6K Signaling Pathway.

Zinc oxide nanoparticles (ZnO-NPs) are increasingly used in sunscreens, food additives, pigments, rubber manufacture, and electronic materials. Several studies have shown that ZnO-NPs inhibit cell growth and induce apoptosis by the production of oxidative stress in a variety of human cancer cells. However, the anti-cancer property and molecular mechanism of ZnO-NPs in human gingival squamous cell carcinoma (GSCC) are not fully understood. In this study, we found that ZnO-NPs induced growth inhibition of GSCC (Ca9-22 and OECM-1 cells), but no damage in human normal keratinocytes (HaCaT cells) and gingival fibroblasts (HGF-1 cells). ZnO-NPs caused apoptotic cell death of GSCC in a concentration-dependent manner by the quantitative assessment of oligonucleosomal DNA fragmentation. Flow cytometric analysis of cell cycle progression revealed that sub-G1 phase accumulation was dramatically induced by ZnO-NPs. In addition, ZnO-NPs increased the intracellular reactive oxygen species and specifically superoxide levels, and also decreased the mitochondrial membrane potential. ZnO-NPs further activated apoptotic cell death via the caspase cascades. Importantly, anti-oxidant and caspase inhibitor clearly prevented ZnO-NP-induced cell death, indicating the fact that superoxide-induced mitochondrial dysfunction is associated with the ZnO-NP-mediated caspase-dependent apoptosis in human GSCC. Moreover, ZnO-NPs significantly inhibited the phosphorylation of ribosomal protein S6 kinase (p70S6K kinase). In a corollary in vivo study, our results demonstrated that ZnO-NPs possessed an anti-cancer effect in a zebrafish xenograft model. Collectively, these results suggest that ZnO-NPs induce apoptosis through the mitochondrial oxidative damage and p70S6K signaling pathway in human GSCC. The present study may provide an experimental basis for ZnO-NPs to be considered as a promising novel anti­tumor agent for the treatment of gingival cancer.

Ferritin expression in the periodontal tissues of primates.

Ferritin, an iron-binding protein, is composed of two subunits, a heavy chain and a light chain. It regulates many biological functions, such as proliferation, angiogenesis, and immunosuppression. The objective of this study was to determine the expression and distribution of ferritin in the periodontal tissuesof primates.First, we assessed the expression of ferritin in primary cultured cells isolated from human periodontal tissues using the polymerase chain reaction and immunofluorescent staining. Second, we investigated the expression and distribution of ferritin in the periodontal tissues of Macaca fascicularis, human gingival tissues, and human gingival carcinoma tissues using immunohistochemistry.Both protein and mRNA of ferritin were constitutively present in human primary cultured cells, including those from the dental apical papilla, periodontal ligament, dental pulp, and gingival epithelium, as well as gingival fibroblasts. In M. fascicularistissues, the immunohistochemical staining was particularly strong in blood vessel and mineralizing areas of the dental pulp and periodontal ligament. Ferritin heavy chain exhibited specific immunopositivity in in the stratum basale of the epithelium in human gingival tissue and strong immunostaining was found in peripheral regions of gingival carcinoma sites. Ferritin is constitutivelypresent andwidelydistributed in the periodontal tissues of primates. Ferritin may play roles in epithelial proliferation, vascular angiogenesis, and mineralization in these tissues.

Cigarette smoke extract (CSE) induces RAGE-mediated inflammation in the Ca9-22 gingival carcinoma epithelial cell line.

OBJECTIVE: The oral environment is anatomically positioned as a significant gateway for exposure to environmental toxicants. Cigarette smoke exposure compromises oral health by orchestrating inflammation. The receptor for advanced glycation end-products (RAGE) has been implicated in smoke-induced inflammatory effects; however, its role in the oral cavity is unknown. The purpose of this study was to determine RAGE expression by immortalized gingival carcinoma cells and the degree to which RAGE-mediated signaling influences inflammation. DESIGN: Gingival epithelia cells (Ca9-22) were exposed to 10% cigarette smoke extract (CSE) for six hours and screened for RAGE expression and inflammatory mediators. RESULTS: Quantitative PCR and immunoblotting revealed increased RAGE expression following exposure. Furthermore, exposure activated RAGE signaling intermediates including Ras and NF-κB. IL-6 and IL-1ß were also elevated in cell culture medium from CSE-exposed cells when compared to controls. A family of anionic, partially lipophilic sulfated polysaccharide derivatives known as semi-synthetic glycosaminoglycan ethers (SAGEs) were used in an effort to block RAGE signaling. Co-treatment of CSE and SAGEs ameliorated inflammatory responses. CONCLUSIONS: These results provide a new perspective on a mechanism of cigarette smoke induced oral inflammation. Further work may show RAGE signaling as a potential target in the treatment of diseases of the oral cavity exacerbated by tobacco smoke exposure.

Methylsulfonylmethane Induces G1 Arrest and Mitochondrial Apoptosis in YD-38 Gingival Cancer Cells.

Gingival squamous cell carcinoma is a rare form of cancer that accounts for less than 10% of all head and neck cancers. Targeted therapies with natural compounds are of interest because they possess high efficacy with fewer side-effects. Methylsulfonylmethane (MSM) is an organic sulfur-containing compound with anticancer activities. The main goal of this study was to induce proliferation inhibition and apoptosis in the metastatic YD-38 cell line. MSM up-regulated expression of P21Waf1/Cip1 and P27Kip1 genes and down-regulated expression of cyclin D1 (CCND1) and CDK4. Moreover, treatment with MSM induced apoptosis and up-regulation of BAX in YD-38 cells. In accordance, the expression of the BCL-2 and BCL-XL, were inhibited, indicating the role of mitochondria in MSM-induced apoptosis. Analysis of mitochondrial integrity showed a loss of mitochondrial potential with an increased level of cytochrome c in the cytosol compared to mitochondria. Active CASPASE-3 (CASP3) was also observed, confirming that MSM-induced apoptosis is caspase-mediated.

Galectin-1 expression is associated with tumour immunity and prognosis in gingival squamous cell carcinoma.

AIMS: Galectin-1 (Gal-1) is a ß-galactoside-binding protein that overexpresses in cancer and plays pivotal roles in tumour progression. Gal-1 regulates angiogenesis and invasiveness, and suppresses tumour immunity by inducing T cell apoptosis. Several studies have examined the relationship between Gal-1 and tumour immunosuppression in vivo, but they have not examined the clinicopathological relationship between Gal-1 expression and apoptotic T cell number in human tissue. In this study, we investigated the association between Gal-1 expression and apoptotic T cells of gingival squamous cell carcinoma (GSCC), as well as other clinicopathological factors. METHODS: Immunohistochemical investigation of 80 GSCC specimens using anti-Gal-1, anti-CD3, anti-CD4, anti-CD8, anti-CD34, antipodoplanin and anticleaved caspase-3 (CC-3) antibodies was performed. Relative expression levels of CD3 and CC-3, as well as CD8 and CC-3 were assessed simultaneously by double immunostaining. Gal-1 expression and T cell apoptosis were evaluated in 6 high-power fields (3 in the tumour and 3 in the stroma). RESULTS: Gal-1 expression in GSCC was significantly correlated with T cell infiltration (p=0.036), and apoptosis of CD3+ and CD8+ T cells (p<0.001). Moreover, Gal-1 expression was significantly correlated with lymph node metastasis (p=0.021), histological differentiation (p<0.001) and overall survival rate (p=0.021). CONCLUSIONS: These findings suggest that Gal-1 plays an important role in immune escape of GSCC cells, and Gal-1 expression level may be a useful clinicopathological prognostic marker for GSCC.

A study of cell proliferation using immunohistological staining: A case report of congenital granular cell epulis.

An unusual case of a 1-day-old Chinese female neonate with a solid tumor mass in the maxillary anterior ridge of the edentulous jaw is reported. Based on the clinical and histopathological features, the diagnosis was of obstructive congenital granular cell epulis (CGCE) which is an uncommon benign tumor that preferentially develops in female infants. Immunohistochemical analysis of the lesion was performed and the rate of cell proliferation was determined by immunostaining with Ki-67 and PCNA, which showed labeling indexes of 11.1% and 33.3%, respectively. No recurrence was observed in the follow-up.

Tannic acid inhibits the Jak2/STAT3 pathway and induces G1/S arrest and mitochondrial apoptosis in YD-38 gingival cancer cells.

Tannic acid (TA), is a potent anti-oxidant, showing anti-proliferative effects on numerous cancers. The ability of TA to induce proliferation inhibition on the rare tumor, gingival squamous cell carcinoma (GSCC), comprising <10% of all head and neck squamous cell carcinomas was studied in the YD-38 cell line. The main goal was to modulate the Jak2/STAT3 pathway using TA and to induce cell cycle arrest and apoptosis in GSCC. TA treatment induced G1 arrest and apoptosis in YD-38 cells. Molecular analysis revealed that TA inhibits Jak2/STAT3 pathway by preventing their expression as well as phosphorylation. This inhibition of STAT3 phosphorylation prevented the nuclear translocation and DNA binding capability of STAT3. Together with the inhibition of transcriptional regulatory function of STAT3, TA inhibited the expression of G1 phase modulators CDK-4, CDK-6, cyclin D1 and cyclin E. It is also evidenced that TA exerted an intense activation of p21Waf1/Cip1, p27Kip1 and p53 genes confirming its role in G1 phase inhibition. Additionally, upon treatment with TA, the expression of mitochondrial pore factors Bax, Bcl-2 and Bcl-XL were changed. We observed inhibition of Bcl-2 and an increase in mitochondrial localization of Bax leading to the loss of mitochondrial membrane potential, resulting in the release of cytochrome c to the cytosol. In addition, we perceived the activation of caspases upon TA treatment. Specific inhibition of caspase protected the cells from TA induced apoptosis. Taken together, this study reveals that TA significantly inhibits the Jak2/STAT3 signaling pathway and induces G1 arrest and mitochondrial apoptosis in YD-38 cells.

Oxytalan-positive peripheral ossifying fibromas express runt-related transcription factor 2, bone morphogenetic protein-2, and cementum attachment protein. An immunohistochemical study.

BACKGROUND: The peripheral ossifying fibroma (POF) represents one of the most common lesions of the periodontal tissues that may originate from the gingival soft tissues, the periosteum, or the periodontal ligament. AIM: To investigate the immunohistochemical expression of runt-related transcription factor 2 (Runx-2), bone morphogenetic protein-2 (BMP-2), and cementum attachment protein (CAP) in oxytalan-positive POF, to establish the use of POF as an in vivo model for the study of the periodontal ligament. MATERIALS AND METHODS: Thirty tumors that presented clinical and histologic features of POF, as well as oxytalan fibers, were included in the study. Immunohistochemical expression of Runx-2, BMP-2, and CAP was evaluated by light microscopy. RESULTS: Runx-2, BMP-2, and CAP were abundantly expressed by POFs; 22 of 30 tumors expressed positive staining for Runx-2, twenty-six tumors for BMP-2, and twenty-five tumors for CAP. The expression of Runx-2 was abundant in POFs where bone was histologically present (P = 0.04) and of BMP-2 in POFs where dystrophic calcifications were present (P = 0.03). CONCLUSION: It is suggested that oxytalan-positive POFs, purportedly originating from the periodontal ligament, express molecules that are specific to bone and cementum (Runx-2, BMP-2), or cementum only (CAP). Thus, the cell populations present in the lesion belong to the mineralized-tissue-forming cell lineages, the cementoblastic or osteoblastic lineage.

[Correlation analysis of VEGF and PTEN expression in gingival carcinoma].

PURPOSE: To study the expression of vascular endothelial growth factor (VEGF) and phosphatase and tensin homolog (PTEN) in gingival carcinoma and their correlation in order to provide reference for clinical treatment. METHODS: Sixty-six gingival cancer patients were determined by pathological examination, among which 31 were well-differentiated, 20 were moderately differentiated and 15 were poorly differentiated. 15 adjacent normal tissues were chosen as control group. The expression of VEGF and PTEN was examined by immunohistochemical method. Correlation analysis was performed with SPSS13.0 software package. RESULTS: The positive rate of PTEN in control group was significantly higher than other groups (P<0.05). The expression of VEGF in poorly differentiated group was significantly higher than other groups (P<0.05). Correlation analysis showed that the expression of VEGF was positively correlated to recurrence and lymph node metastasis (P<0.05); PTEN was negatively correlated to recurrence and lymph node metastasis (P<0.05); VEGF and PTEN in gingival carcinoma was negatively correlated (P<0.05). CONCLUSIONS: The increased expression of VEGF and decreased expression of PTEN in gingival carcinoma may play a mutual role in the development of gingival cancer.

Methanolic extracts of Solieria robusta inhibits proliferation of oral cancer Ca9-22 cells via apoptosis and oxidative stress.

Many red algae-derived natural products are known to have anticancer effects. The biological functions of the red alga Solieria robusta from the Karachi coast (Pakistan) remain unclear. Here, we prepared a methanolic extracts of S. robusta (MESR) to examine its possible anti-oral cancer effects and the corresponding mechanism of action. Cell viability of MESR-incubated oral cancer Ca9-22 cells was dose-responsively decreased (p<0.001). According to a propidium iodide (PI)-based assay the cell cycle distribution was dramatically changed, especially for subG1 accumulation. Annexin V/PI assay of apoptosis using flow cytometry also showed that MESR-incubated Ca9-22 cells were dose-responsively increased (p<0.001). For evaluation of oxidative stress in MESR-incubated Ca9-22 cells, we found that reactive oxygen species (ROS) were overexpressed dose- and time-responsively and mitochondrial depolarization was also increased (p<0.001). Taken together, MESR showed inhibitory effects on oral cancer proliferation coupled with apoptosis and oxidative stress.

Congenital granular cell epulis.

Congenital granular cell epulis is a rarely reported lesion of unknown histogenesis with a strong predilection for the maxillary alveolar ridge of newborn girls. Microscopically, it demonstrates nests of polygonal cells with granular cytoplasm, a prominent capillary network, and attenuated overlying squamous epithelium. The lesion lacks immunoreactivity for S-100, laminin, chromogranin, and most other markers except neuron-specific enolase and vimentin. Through careful observation of its unique clinical, histopathologic, and immunohistochemical features, this lesion can be distinguished from the more common adult granular cell tumor as well as other differential diagnoses.

High interstitial fluid pressure promotes tumor progression through inducing lymphatic metastasis-related protein expressions in oral squamous cell carcinoma.

OBJECTIVE: The present study was carried out to analyze the interstitial fluid pressure (IFP) values in patients with oral squamous cell carcinoma and identify the relationship between the IFP and tumor prognosis. METHODS: We investigated tumor lymphatic metastasis-related protein (VEGFC, VEGFD and VEGFR3) expressions change on SCC-4 and SCC-9 cells subjected to increased extracellular pressure in vitro and analyzed the relationship between these proteins and IFP, and prognosis of patients with oral squamous cell carcinoma. RESULTS: The results showed that the elevated extracellular pressure significantly resulted in a dramatic increase of VEGFC, VEGFD and VEGFR3 protein expressions in OSCC. More important, the activation of VEGFC, VEGFD and VEGFR3 proteins through IFP elevation contributed to poor prognosis for patients with OSCC. CONCLUSIONS: These results suggest an important potential clinical application of measuring IFP, which can be used as a generic marker of prognosis evaluation and response to therapy. Furthermore, VEGFC, VEGFD and VEGFR3 may be useful targets in developing novel and specific therapeutic tool for OSCC patients with high IFP.

[Cytokeratin expression in cervical lymph nodes of patients with mandibular gingival squamous cell carcinoma].

OBJECTIVE: To examine the cytokeratin expression in cervical lymph nodes of patients with mandibular gingival squamous cell carcinoma and its clinical significance. METHODS: The data of 42 cases with mandibular gingival squamous cell carcinoma after operation from July 2009 to December 2012 were included. Forty-two patients (male = 27, formale = 15) were included, with a mean age of 54.1 years (range 27-77). The lesions were staged (stage I:9, stage II:16, stage III:6, stage IV:11). The cervical lymph nodes were examined by immunohistochemistry and HE. The cytokeratin expression in the lymph nodes was analyzed. RESULTS: The rates of lymph nodes metastasis detected by routine HE staining, serial sections HE staining and IHC were 8.0% (47/585), 9.6% (56/585) and 12.8% (75/585), respectively. There was significant difference (χ(2) = 7.17, P < 0.01) in the diagnosis of lymph nodes metastasis between IHC and routine HE staining, There was no significant difference between IHC and serial HE staining (χ(2) = 3.10, P > 0.05). Metastasis occurred mainly in the Level I, II and III. Nineteen lymph nodes in 12 patients were found micrometastasis with IHC. Serial sections and routine HE staining did not find micrometastasis. CONCLUSIONS: CK markers is sensitive in detecting lymph node metastasis of mandibular gingival squamous cell carcinoma.

Peripheral cementifying fibroma: a clinical diagnostic dilemma.

The peripheral ossifying fibroma (POF) is a reactive gingival overgrowth occurring frequently in the anterior maxilla. It originates in the cells of the periodontal ligament and is more common in children and young adults. In the current article a case of gingival over growth, which was thought to be puberty-induced gingivitis was seen in the lower anterior maxillary gingiva. Histology of the excised tissue showed cellular, fibrous connective tissue stroma with calcified osseous calcifications indicative of POF. The definitive diagnosis is established only by histological examination, which revealed the presence of highly cellular connective tissue with focal calcifications. Surgery is the treatment of choice, though the recurrence rate can reach 20% in case of POF. After histological confirmation the recall and clinical evaluation protocol of POF varies due to its increased recurrence rate, which the general dentist should be aware of.

Cardiotoxin III inhibits proliferation and migration of oral cancer cells through MAPK and MMP signaling.

Cardiotoxin III (CTXIII), isolated from the snake venom of Formosan cobra Naja naja atra, has previously been found to induce apoptosis in many types of cancer. Early metastasis is typical for the progression of oral cancer. To modulate the cell migration behavior of oral cancer is one of the oral cancer therapies. In this study, the possible modulating effect of CTXIII on oral cancer migration is addressed. In the example of oral squamous carcinoma Ca9-22 cells, the cell viability was decreased by CTXIII treatment in a dose-responsive manner. In wound-healing assay, the cell migration of Ca9-22 cells was attenuated by CTXIII in a dose- and time-responsive manner. After CTXIII treatment, the MMP-2 and MMP-9 protein expressions were downregulated, and the phosphorylation of JNK and p38-MAPK was increased independent of ERK phosphorylation. In conclusion, CTXIII has antiproliferative and -migrating effects on oral cancer cells involving the p38-MAPK and MMP-2/-9 pathways.

Interleukin-4 receptor α-based hybrid peptide effectively induces antitumor activity in head and neck squamous cell carcinoma.

Interleukin-4 receptor α (IL-4Rα) is highly expressed on the surface of various human solid tumors including head and neck squamous cell carcinoma (HNSCC). We designed a novel IL-4Rα-lytic hybrid peptide composed of a binding peptide to IL-4Rα and a cell-lytic peptide. In the present study, we evaluated the antitumor activity of the IL-4Rα-lytic hybrid peptide as a novel molecular-targeted therapy in HNSCC. Immunoblot analysis revealed that IL-4Rα was expressed in all tested HNSCC cell lines (HSC-2, HSC-3, HSC-4, Ca9-22 and OSC-19), but not in a human normal keratinocyte (HaCaT) cell line. Immunohistochemical expression levels of IL-4Rα in HNSCC tissues were higher compared to those in normal epithelial tissue. The IL-4Rα-lytic hybrid peptide showed cytotoxic activity in all five cancer cell lines with a concentration that killed 50% of all cells (IC50) as low as 10 µM. HaCaT cells were less sensitive to this peptide with an IC50 of >30 µM. In addition, intratumoral administration of IL-4Rα-lytic hybrid peptide significantly inhibited tumor growth in a xenograft model of human HNSCC in vivo. These results indicate that the IL-4Rα-lytic hybrid peptide may serve as a potent agent to provide a novel therapy for patients with HNSCC.

Assessment of angiogenic markers and female sex hormone receptors in pregnancy tumor of the gingiva.

PURPOSE: Oral pregnancy tumors (OPTs) arise on the inflamed gingiva of women after the first trimester of pregnancy. The expression of angiogenic markers and female hormone receptors was assessed. MATERIALS AND METHODS: Immunohistochemistry was used to analyze the expression of estrogen and progesterone receptors and the expression of angiogenic factors, such as vascular endothelial growth factor (VEGF) and its receptor, fibroblast growth factor (FGF), and hypoxia inducible factors 1α and 3α (HIF1α and HIF3α). Experimental groups included 9 OPTs, 10 oral pyogenic granulomas from nonpregnant women of the same age, and 9 oral pyogenic granulomas from postmenopausal women. RESULTS: VEGF expression in stromal histiocytes and endothelial cells of small vessels was positively correlated in the OPT group (P < .05 by χ(2) test). VEGF receptor also was overexpressed in stromal histiocytes and endothelial cells of OPTs compared with oral pyogenic granulomas from nonpregnant and postmenopausal women (P < .005 by χ(2) test). No correlation was detected among estrogen and progesterone receptors, FGF and HIF1α and HIF3α (ER and PgR respectively) in the 3 experimental groups. CONCLUSIONS: VEGF-associated angiogenesis is most likely involved in the pathogenesis of the lesion. These results imply that local inhibition of VEGF activity could be an adjuvant therapeutic approach for OPTs to control hemorrhage, which can be massive at the surgical excision of such lesions during pregnancy.