Bruno C. Jham

Oral health status of 207 head and neck cancer patients before, during and after radiotherapy

The aim of this retrospective study was to describe the oral health status of patients before, during, and after radiotherapy (RT) for the treatment of head and neck cancer (HNC). Before RT, the following data was collected: presence of unrecoverable teeth, residual roots, unerupted teeth, use of dentures, periodontal alterations, caries, candidiasis, and xerostomia. Mucositis, candidiasis, and xerostomia were evaluated during RT. Patients continued to be followed after RT for evaluation of mucositis, candidiasis, xerostomia, radiation caries, and osteoradionecrosis. For statistical analysis, 95% confidence intervals (CI) were determined using sample size, population, and percentages. Before RT, 120 (57.9%) patients presented with alterations in the oral cavity namely, 85 (41.0%) with periodontal disease, 44 (21.2%) with residual roots, 25 (12.0%) with caries, 15 (7.2%) with candidiasis, and 12 (5.8%) had an unerupted tooth present. Xerostomia was a complaint of 19 patients (9.1%). Restorations were indicated for 33 patients (15.9%), whereas extraction was indicated for 104 (50.2%) patients. During RT, mucositis was found in 80 (61.7%) patients, candidiasis in 60 (45.8%), and xerostomia was a complaint of 82 patients (62.6%). After RT, mucositis persisted in 21 patients (19.2%), candidiasis was identified in 23 patients (21.1%), and xerostomia was reported by 58 patients (53.2%). Radiation caries developed in 12 patients (11.0%), whereas six patients (5.5%) developed osteoradionecrosis. The demographic profile herein presented will be useful as baseline data to provide additional epidemiological information and to determine future measures for prevention and treatment of RT-induced complications and sequelae.

Viral G protein-coupled receptor up-regulates Angiopoietin-like 4 promoting angiogenesis and vascular permeability in Kaposi's sarcoma

Kaposis sarcoma (KS) is an enigmatic vascular tumor thought to be a consequence of dysregulated expression of the human herpesvirus-8 (HHV-8 or KSHV)-encoded G protein-coupled receptor (vGPCR). Indeed, transgenic animals expressing vGPCR manifest vascular tumors histologically identical to human KS, with expression of the viral receptor limited to a few cells, suggestive of a paracrine mechanism for vGPCR tumorigenesis. Both human and vGPCR experimental KS lesions are characterized by prominent angiogenesis and vascular permeability attributed to the release of angiogenic molecules, most notably vascular endothelial growth factor. However, the relative contribution of these paracrine mediators to the angiogenic and exudative phenotype of KS lesions remains unclear. Here we show that vGPCR up-regulation of Angiopoietin-like 4 (ANGPTL4) plays a prominent role in promoting the angiogenesis and vessel permeability observed in KS. Indeed, ANGPTL4 expression is a hallmark of vGPCR experimental and human KS lesions. Inhibition of ANGPTL4 effectively blocks vGPCR promotion of the angiogenic switch and vascular leakage in vitro and tumorigenesis in vivo. These observations suggest that ANGPTL4 is a previously unrecognized target for the treatment of patients with KS. As angiogenesis and increased vessel permeability are common themes in all solid tumors, these findings may have a broad impact on our understanding and treatment of cancer.

A survey of 460 supernumerary teeth in Brazilian children and adolescents

OBJECTIVE This study aimed to survey the demographic profile of supernumerary teeth (ST) in Brazilian children and adolescents. METHODS A retrospective analysis was carried out of all nonsyndromic patients with ST attended at the Pediatric Oral Surgery Service of the Universidade Federal de Minas Gerais between 1995 and 2004. Diagnosis of ST was based on clinical and radiographic examination. Chi-squared test was used for statistical analysis. RESULTS This study included 460 ST found in 305 patients. Radiographic assessment (32.1%) was the main care-seeking reason and also the means through which most (97.6%) permanent ST were identified. Most cases were single (63.0%), conical (44.6%), and unerupted (76.8%) ST. Most teeth were fully developed (41.3%), normally orientated (78.9%), placed in a palatal/lingual-sagittal position (84.1%), adjacent to the crown of permanent teeth (50.2%) (P < 0.001). The most frequent clinical complication was permanent teeth displacement (36.0%). Treatment was surgical removal followed by orthodontics (61.6%). CONCLUSIONS The demographic profile of ST herein presented will be useful to provide additional epidemiological information. A wide range of factors should be considered when evaluating ST. In addition, it is essential to detect ST as early as possible to avoid complications and to assure successful management. Even after treatment, patients must be followed up.

Dual Inhibition of PI3Kα and mTOR as an Alternative Treatment for Kaposi's Sarcoma

Rapamycin (or sirolimus), the prototypical inhibitor of the mammalian target of rapamycin (mTOR) and an immunosuppressant used for the prevention of renal transplant rejection, has recently emerged as an effective treatment for Kaposis sarcoma (KS), an enigmatic vascular tumor and a model for pathologic angiogenesis. Indeed, recent work supports a role for mTOR as a central player in the transformation of endothelial cells by the KS-associated herpesvirus-encoded G protein-coupled receptor (vGPCR), the viral oncogene believed to be responsible for causing KS. However, emerging evidence that rapamycin may transiently promote the activation of Akt may limit its use as an anti-KS therapy. Here, we show that activation of Akt in endothelial cells expressing vGPCR is augmented by treatment with rapamycin, resulting in the up-regulation of several Akt proliferative and survival pathways. However, use of a novel dual phosphatidylinositol 3-kinase alpha (PI3Kalpha)/mTOR inhibitor, PI-103, effectively and independently blocked activation of both PI3K and mTOR in vGPCR-expressing endothelial cells. This resulted in more effective inhibition of endothelial cell proliferation and survival in vitro and tumor growth in vivo. Our results suggest that PI-103 may be an effective therapeutic option for the treatment of patients with KS. Moreover, as KS may serve as a model for pathologic angiogenesis, our results further provide the basis for the early assessment of PI-103 as an antiangiogenic chemotherapeutic.

Amplification of the Angiogenic Signal through the Activation of the TSC/mTOR/HIF Axis by the KSHV vGPCR in Kaposi's Sarcoma

Background Kaposis sarcoma (KS) is a vascular neoplasm characterized by the dysregulated expression of angiogenic and inflammatory cytokines. The driving force of the KS lesion, the KSHV-infected spindle cell, secretes elevated levels of vascular endothelial growth factor (VEGF), essential for KS development. However, the origin of VEGF in this tumor remains unclear. Methodology/Principal Findings Here we report that the KSHV G protein-coupled receptor (vGPCR) upregulates VEGF in KS through an intricate paracrine mechanism. The cytokines secreted by the few vGPCR-expressing tumor cells activate in neighboring cells multiple pathways (including AKT, ERK, p38 and IKKβ) that, in turn, converge on TSC1/2, promoting mTOR activation, HIF upregulation, and VEGF secretion. Conditioned media from vGPCR-expressing cells lead to an mTOR-dependent increase in HIF-1α and HIF-2α protein levels and VEGF upregulation. In a mouse allograft model for KS, specific inhibition of the paracrine activation of mTOR in non-vGPCR-expressing cells was sufficient to inhibit HIF upregulation in these cells, and abolished the ability of the vGPCR-expressing cells to promote tumor formation in vivo. Similarly, pharmacologic inhibition of HIF in this model blocked VEGF secretion and also lead to tumor regression. Conclusions/Significance Our findings provide a compelling explanation for how the few tumor cells expressing vGPCR can contribute to the dramatic amplification of VEGF secretion in KS, and further provide a molecular mechanism for how cytokine dysregulation in KS fuels angiogenesis and tumor development. These data further suggest that activation of HIF by vGPCR may be a vulnerable target for the treatment of patients with KS.

Granulomatous Foreign-Body Reaction Involving Oral and Perioral Tissues After Injection of Biomaterials: A Series of 7 Cases and Review of the Literature

PURPOSE Injectable implants used for soft-tissue augmentation may lead to a granulomatous foreign-body reaction. The aim of this report is to present 7 new cases of foreign-body granulomas involving the oral and perioral tissues, after injection of biomaterials to achieve soft-tissue augmentation. In addition, the clinical and epidemiological profile of this condition is summarized, based on a review of the English-language literature of all previously described cases. PATIENTS AND METHODS We report on 7 new cases of granulomatous foreign-body reaction involving the oral and perioral tissues after the injection of biomaterials. A comprehensive literature review is also presented. RESULTS The literature search revealed 49 cases of this condition affecting the oral and perioral tissues. Our 7 patients were female, with a mean age of 52.8 years (range, 34 to 70 years). The lower lip was affected in 4 cases, 1 case was located in the upper lip, 1 case in the buccal mucosa, while 1 case involved 2 different sites (upper lip and buccal mucosa). Histopathologic examination revealed numerous cells with clear, often multiple, cytoplasmic vacuoles, bearing a resemblance to lipoblasts. Immunohistochemistry revealed diffuse positivity for the histiocytic marker CD68. CONCLUSIONS The diagnosis of granulomatous foreign-body reactions may be challenging because of their microscopic resemblance to liposarcoma, and because of the occasional reluctance of patients to report the previously performed esthetic procedure. A clinical history, histopathologic examination, and immunohistochemical analysis (as needed) are essential in achieving an accurate diagnosis.

The Kaposi's sarcoma‐associated herpesvirus G protein‐coupled receptor: Lessons on dysregulated angiogenesis from a viral oncogene

Tumor viruses can induce cell transformation by overcoming cellular defense mechanisms and promoting the ungoverned proliferation of infected cells. To this end, functionally related viral oncogenes have evolved in disparate viruses to over‐ride key proliferative and survival intracellular pathways, thus assuring efficient viral replication and contributing to tumor formation. Indeed, the study of viral oncogenes has been a powerful tool for disclosing fundamental insights into these basic cellular processes. In this regard, the Kaposis sarcoma‐associated herpesvirus (KSHV or HHV8), the etiological agent of Kaposis sarcoma (KS), is an exemplary model of an oncogenic virus that includes within its genome several homologues of cellular genes implicated in the regulation of cell proliferation and apoptosis. However, emerging evidence now points to a single KSHV gene, ORF74, encoding for the viral G protein‐coupled receptor (vGPCR), as essential for KS development. Expressed in only a fraction of cells within KS lesions, this viral receptor induces tumorigenesis through both autocrine and paracrine mechanisms. Indeed, work from several laboratories has demonstrated that vGPCR can promote cell proliferation, enhance cell survival, modulate cell migration, stimulate angiogenesis, and recruit inflammatory cells, both in expressing cells, as well as in neighboring (bystander) cells. Examination of this powerful viral oncogene may expose novel targets for the treatment of patients with KS and could ultimately provide a unique perspective into how GPCRs, and specifically chemokine receptors, contribute to angiogenesis and tumorigenesis. J. Cell. Biochem. 110: 1–9, 2010.

Histopathologic findings in bone from edentulous alveolar ridges: a role in osteonecrosis of the jaws?

Bisphosphonate-related osteonecrosis of the jaws (BONJ) is characterized by a breach in the oral mucosa with exposure of necrotic bone. Although bisphosphonates impact multiple biologic processes, including bone turnover and vascularity, factors contributing to the pathogenesis of BONJ remain poorly understood. In this retrospective analysis, the histopathologic findings from 154 alveolar bone specimens obtained during osteotomy preparation for dental implant placement were reviewed from 147 consecutively treated patients [male (79); female (68); Caucasian (141); African-American (6)]. The alveolar ridge sites had been edentulous for 1 year or longer. None of the patients in this study had a history of bisphosphonate therapy or clinical evidence of BONJ. Two pathologists, masked, using predetermined criteria, reviewed and substantiated the pathology reports provided by the licensed pathology service. In selected cases, special stains had been conducted to help establish the presence of bacteria. The histopathologic findings for the core specimens were as follows: 76 viable bone (49.4%); 54 nonviable bone (35.0%); and 24 osteomyelitis (15.6%). These histopathologic findings indicate that the edentulous jaw can contain regions of nonviable bone and microbial biofilm formation for 1 year or more after tooth extraction and mucosal healing. Regions of necrotic bone and subclinical infection may contribute to the development of untoward clinical events, such BONJ and early implant failure.

Angiopoietin-like 4: A novel molecular hallmark in oral Kaposi’s sarcoma

Kaposis sarcoma (KS) remains among the most common causes of oral cancer in HIV-infected individuals. Infection with the KS-associated herpesvirus (KSHV/HHV8) is a necessary event for disease development. Emerging evidence suggests that KSHV infects vascular endothelial (or endothelial progenitor) cells promoting the formation of the KS tumor (or spindle) cell. These cells elaborate angiogenic growth factors and cytokines that promote the dysregulated angiogenesis and profuse edema that characterizes this unusual vascular tumor. Central among these secreted factors is the potent endothelial cell mitogen, vascular endothelial growth factor (VEGF). Indeed, VEGF has proven to be a key player in KSHV pathogenesis and is a molecular hallmark of KS lesions. We have recently shown that a second angiogenic factor, Angiopoietin-like 4 (ANGPTL4), may also play a critical role in KS development. Here we demonstrate that ANGPTL4 is upregulated both directly and indirectly by the KSHV oncogene, vGPCR. We further show that ANGPTL4 is a molecular hallmark of oral KS lesions. Indeed, expression of this protein was observed in more tumor cells and in more biopsies specimens than expression of VEGF (23/25 or 92% vs. 19/25 or 76%, respectively) in oral KS. These surprising results support a key role for ANGPTL4 in Kaposis sarcomagenesis and further suggest that this angiogenic factor may provide a novel diagnostic and therapeutic marker for oral KS patients.

Midkine expression in oral squamous cell carcinoma and leukoplakia.

BACKGROUND Midkine (MK), a 13-kDa heparin-binding growth factor, is overexpressed in various human cancers. However, its role in the development and progression of oral cavity squamous cell carcinoma (OCSCC) is still unclear. Thus, the aim of this study was to evaluate the expression of MK in samples of OCSCC, leukoplakia, and healthy oral mucosa (control). METHODS Surgically excised specimens from patients with primary OCSCC (n = 28) were immunostained for MK, Ki-67, PCNA, p53, bcl-2, Bax, and CD31. Besides this, MK expression was also investigated in leukoplakia and normal oral mucosa. The relationship of MK(+) cells with clinical parameters (tumor location, tumor size, lymph node metastasis, and survival) and microscopic parameters (WHO histological grading, intensity of inflammation, proliferation index, apoptosis, and angiogenesis) was also evaluated. RESULTS The results showed that MK expression was increased in OCSCC in relation to leukoplakia and normal mucosa. Furthermore, MK expression was increased in late-stage tumors (T3/T4) compared with early-stage lesions (T1/T2). MK-positive lesions also showed increased expression of the anti-apoptotic protein bcl-2. CONCLUSION OCSCC, particularly late-stage tumors, exhibits increased MK expression, which may be involved in tumor progression via upregulation of anti-apoptotic genes, as shown by the augmented bcl-2 positivity in MK-positive tumors.