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Anticancer Res ; 41(12): 6061-6065, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34848460


BACKGROUND/AIM: Antimony is a chemical element used in the therapy of parasitic diseases with a promising anticancer potential. The aim of this study was to evaluate in vitro activity of free or liposomal vesicle-packed antimony trioxide (AT or LAT) in the t(15;17)(q22;q21) translocation-positive acute promyelocytic leukemia (APL) cell line NB4. MATERIALS AND METHODS: Cytotoxicity was analysed with trypan blue exclusion, the MTT assay and neutral red exclusion assay; cell proliferation with PicoGreen®; and reactive oxygen species (ROS) production with DCFDA. RESULTS: Liposomal particles did not change the pH of the cell culture medium and entered the cells. Both formulations resulted in a time- and concentration-dependent cytotoxicity and production of ROS. LAT showed higher toxicity at lower concentrations compared to AT. CONCLUSION: LAT may be used to decrease drug dosage and maintain high anti-tumoral effects on APL cells.

Front Oncol ; 11: 686445, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34650910


In approximately 15% of patients with acute myeloid leukemia (AML), total and phosphorylated EGFR proteins have been reported to be increased compared to healthy CD34+ samples. However, it is unclear if this subset of patients would benefit from EGFR signaling pharmacological inhibition. Pre-clinical studies on AML cells provided evidence on the pro-differentiation benefits of EGFR inhibitors when combined with ATRA or ATO in vitro. Despite the success of ATRA and ATO in the treatment of patients with acute promyelocytic leukemia (APL), therapy-associated resistance is observed in 5-10% of the cases, pointing to a clear need for new therapeutic strategies for those patients. In this context, the functional role of EGFR tyrosine-kinase inhibitors has never been evaluated in APL. Here, we investigated the EGFR pathway in primary samples along with functional in vitro and in vivo studies using several APL models. We observed that total and phosphorylated EGFR (Tyr992) was expressed in 28% and 19% of blast cells from APL patients, respectively, but not in healthy CD34+ samples. Interestingly, the expression of the EGF was lower in APL plasma samples than in healthy controls. The EGFR ligand AREG was detected in 29% of APL patients at diagnosis, but not in control samples. In vitro, treatment with the EGFR inhibitor gefitinib (ZD1839) reduced cell proliferation and survival of NB4 (ATRA-sensitive) and NB4-R2 (ATRA-resistant) cells. Moreover, the combination of gefitinib with ATRA and ATO promoted myeloid cell differentiation in ATRA- and ATO-resistant APL cells. In vivo, the combination of gefitinib and ATRA prolonged survival compared to gefitinib- or vehicle-treated leukemic mice in a syngeneic transplantation model, while the gain in survival did not reach statistical difference compared to treatment with ATRA alone. Our results suggest that gefitinib is a potential adjuvant agent that can mitigate ATRA and ATO resistance in APL cells. Therefore, our data indicate that repurposing FDA-approved tyrosine-kinase inhibitors could provide new perspectives into combination therapy to overcome drug resistance in APL patients.

Autops Case Rep ; 11: e2021302, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34249797


Squamous odontogenic tumor (SOT) is a rare benign neoplasm of the jaw that likely arises from remnants of the dental lamina. It is a slow-growing lesion, with a radiolucent appearance in the central variant. Microscopically, SOT shows islands of squamous epithelium supported by fibrous stroma. In rare cases, squamous odontogenic tumor-like proliferation (SOT-LP) can be observed arising from odontogenic cysts (SOT-LPOC). Herein, we describe the case of a 42-year-old man who presented with discreet bleeding in the maxillary gingiva. Imaging revealed a well-defined, ovoid-shaped lesion with sclerotic margins involving tooth #18 in the intraosseous location. Fine needle aspiration supported the cystic nature of the lesion. After surgery, microscopy revealed a dentigerous cyst showing SOT-LP features. There was no recurrence after a 3-year follow-up. To the best of our knowledge, this is the first report of a dentigerous cyst showing SOT-LP features in the maxilla. Such cysts should be identified to avoid misdiagnosis, with the finding having therapeutic and prognostic implications.

Immunobiology ; 226(3): 152072, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33677150


Macrophages are phagocytic cells with essential participation in immunological events of the oral cavity. However, the role of these cells in oral lichen planus (OLP) and oral lichenoid lesions (OLL) remains unclear. The present study aimed to evaluate the density of macrophages in OLP and OLL, and to compare it with that of oral inflammatory fibrous hyperplasia (OIFH) (control group). 14 cases of OLP, 14 cases of OLL and 14 cases of OIFH were selected for immunohistochemical analysis of CD68+ (M1) and CD163+ (M2) macrophage expression. CD68+ and CD163+ macrophages densities were measured in the intraepithelial and subepithelial areas. The statistical tests used were multivariate analysis of variance, as well as a correlation and linear regression. OLP has more CD68+ macrophages when comparing with OLL (p = 0.001) and OIFH (p = 0.045). There is a very strong relationship between the macrophages types (p < 0.0001) in OLP and OLL. The linear regression showed that to OLL development (p < 0.0001/R2' = 0.9584), the presence of different types of macrophages are more essential than to OLP (p < 0.0001/R2' = 0.8983). However, in the OLP these dependencies are also largely. CD68+ macrophages may be associated with immunopathogenesis of OLP, indicating a pro-inflammatory activity and regulatory role in the type of T-cell response. Besides, CD68+ macrophages can cooperate in the diagnosis of OLP. These results are essential to future studies that seek a therapeutic target for OLP and OLL.

Arch Oral Biol ; 124: 105027, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33550012


OBJECTIVE: the aim of this study was to evaluate the density of Langerhans cells in oral lichen planus (OLP) and oral lichenoid lesions (OLL). DESIGN: 14 cases of OLP, 15 cases of OLL and 14 cases of oral inflammatory fibrous hyperplasia (OIFH), were selected for immunohistochemical analysis of CD1a, CD207 and S100 expression. The OIFH group was subdivided according to the presence (OIFHL n = 14) or absence (OIFHNL n = 14) of lichenoid inflammatory infiltrate. Positive cells were counted in intraepithelial and subepithelial areas. Results were analyzed by multivariate comparative analysis, correlation analysis, linear regression models and Student's T-test. RESULTS: A significantly higher amount of CD207+ cells in OLL vs OLP was observed (p = 0.015). The prevailing reticular pattern observed was CD207high for OLP (p = 0.0329). A statistically significant difference in the expression of CD1a and CD207 was observed for intraepithelial vs subepithelial areas (p = 0.024 and p=0.015, for CD1a and CD207, respectively). Significant correlations were also observed between the expression of CD1a + and CD207+ cells in the pathogenesis of OLP and OLL. CONCLUSION: High levels of CD207+cells in OLP compared with OLL may help explain the differences in the immunopathogenesis of both diseases. Additionally, CD1a + and CD207+ cells appear to be more essential to immunopathogenesis of OLL than to the pathogenesis of OLP.

Líquen Plano Bucal , Erupções Liquenoides , Humanos , Células de Langerhans
Int J Paediatr Dent ; 27(3): 231-235, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27914098


BACKGROUND: Localized juvenile spongiotic gingival hyperplasia (LJSGH) is a distinct subtype of inflammatory gingival hyperplasia that shows lack of response to traditional periodontal treatment, and after surgical excision, recurrence rate of 6-16% has been reported. CASE REPORT: Two girls (11- and 9-year-old) with multifocal red patches along the maxillary and mandibular labial gingiva showed no regression of the lesions after basic periodontal treatment. Surgical excision of focal lesion in each case was performed, which showed typical features of LJSGH. In both cases, the lesions presented recurrence. Hence, cryotherapy sessions in all lesions were performed. CONCLUSION: Cryotherapy appears to be successfully in LJSGH and well received by paediatric patients.

Criocirurgia/métodos , Hiperplasia Gengival/cirurgia , Criança , Feminino , Gengivite/cirurgia , Humanos , Mandíbula/cirurgia , Maxila/cirurgia , Recidiva , Reoperação