Research progress in the mechanism and treatment of osteosarcoma / 中华医学杂志(英文版)

Osteosarcoma (OS) is the most common primary malignant bone tumor that more commonly occurs in children and adolescents. The most commonly used treatment for OS is surgery combined with chemotherapy, but the treatment outcomes are typically unsatisfactory. High rates of metastasis and post-treatment recurrence rates are major challenges in the treatment of OS. This underlines the need for studying the in-depth characterization of the pathogenetic mechanisms of OS and development of more effective therapeutic modalities. Previous studies have demonstrated the important role of the bone microenvironment and the regulation of signaling pathways in the occurrence and development of OS. In this review, we discussed the available evidence pertaining to the mechanisms of OS development and identified therapeutic targets for OS. We also summarized the available treatment modalities for OS and identified future priorities for therapeutics research.

GKK1032B from endophytic Penicillium citrinum induces the apoptosis of human osteosarcoma MG63 cells through caspase pathway activation / 中国天然药物

Chemical investigation of the culture extract of an endophytic Penicillium citrinum from Dendrobium officinale, afforded nine citrinin derivatives (1-9) and one peptide-polyketide hybrid GKK1032B (10). The structures of these compounds were determined by spectroscopic methods. The absolute configurations of 1 and 2 were determined for the first time by calculation of electronic circular dichroism (ECD) data. Among them, GKK1032B (10) showed significant cytotoxicity against human osteosarcoma cell line MG63 with an IC50 value of 3.49 μmol·L-1, and a primary mechanistic study revealed that it induced the apoptosis of MG63 cellsvia caspase pathway activation.

Diosmetin inhibits cell proliferation and promotes apoptosis through STAT3/c-Myc signaling pathway in human osteosarcoma cells

BACKGROUND: Diosmetin is a bioflavonoid compound naturally abundant in citrus fruits. It is found to perform a variety of activities, while its antitumor property in osteosarcoma, a malignant tumor with unmet clinical treatment, remained unknown. METHODS: Colony formation assay, cell cycle analysis and apoptosis analysis were conducted respectively to observe the effect of diosmetin on cell proliferation and apoptosis in human osteosarcoma cells. Western blot and immunoprecipitation were used to detect the expression of apoptotic molecules and activation of STAT3/c-Myc pathway in Saos-2 and U2SO cells. RESULTS: Diosmetin significantly inhibited cell proliferation, induced cell cycle arrest at G2/M phase and promoted cell apoptosis in both Saos-2 and U2SO cells. Moreover, Diosmetin downregulated the expression of anti-apoptotic protein Bcl-xL while upregulated the levels of pro-apoptotic proteins including cleaved Caspase-3, cleaved-PARP and Bax. Furthermore, diosmetin dose-dependently inhibited STAT3 phosphorylation, reduced the expression of its downstream protein c-Myc and impeded the interaction between STAT3 molecules. CONCLUSIONS: These results suggest that diosmetin exerts anti-osteosarcoma effects by suppressing cell proliferation and inducing apoptosis via inhibiting the activation of STAT3/c-Myc signaling pathway, which provide the possibility for diosmetin to be a chemotherapeutic candidate for osteosarcoma.

Avaliação do Efeito do Laser Preventivo na Mucosite Oral Quimioinduzida em Pacientes Submetidos a Altas Doses de Metotrexato / Evaluation of the Effect of Preventive Laser on Chemo-induced Oral Mucositis in Patients Submitted to High Doses of Methotrexate / Evaluación del Efecto del Láser Preventivo em la Mucositis Oral Inducida por Quimioterapia en Pacientes Sometidos a Altas Dosis de Metotrexato

Introdução: A quimioterapia, uma das formas de tratamento de neoplasias malignas, tem sua administração associada a inúmeras drogas, sendo uma delas o metotrexato (MTX), de alta toxicidade, responsável por inúmeros fatores agravantes para a saúde e bem-estar do paciente. Uma das principais complicações é a mucosite oral, manifestação clínica resultante do tratamento oncológico que pode interferir no tratamento e na cura. Objetivo: Avaliar, comparativamente, por meio de um estudo retrospectivo, o efeito do laser preventivo na ocorrência da mucosite oral quimioinduzida em pacientes com osteossarcoma não metastático submetidos a altas doses de MTX, bem como a intensidade da mucosite oral, utilizando o laser preventivo após os ciclos quimioterápicos contendo o medicamento MTX nos pacientes atendidos no Hospital de Câncer infantojuvenil de Barretos/SP. Método: Estudo de coorte com coleta retrospectiva em prontuários. Os pacientes foram divididos em dois grupos, um submetido à terapia profilática com laser de baixa intensidade após infusão do MTX e outro grupo não submetido a essa terapia. Resultados: Os dados obtidos mostraram que houve redução da gravidade da mucosite oral com o uso da laserterapia preventiva, com resultados estatisticamente significativos (p<0,001), corroborando os resultados encontrados na literatura. Conclusão: O uso da laserterapia é uma terapêutica auxiliar importante na prevenção e na redução da severidade da mucosite oral em pacientes submetidos a altas doses de MTX, diminuindo o número de internações por mucosite e os atrasos no protocolo terapêutico, o que reduz gastos e melhora o prognóstico para o paciente.

Introduction: Chemotherapy, one of the treatments for malignant neoplasms, is associated to innumerous drugs, one of them methotrexate (MTX), of high toxicity, responsible for several health damages and impact on the patient's well-being. One of the main complications is oral mucositis, a clinical manifestation resulting from the oncologic treatment that can interfere in the treatment and cure. Objective: To evaluate comparatively through a retrospective study, the effect of preventive laser in the occurrence of chemo-induced oral mucositis in patients with non-metastatic osteosarcoma submitted to high doses of methotrexate (MTX), and the intensity of oral mucositis, using the preventive laser after the chemotherapy cycles containing the drug methotrexate (MTX) in the patients treated at the Child and Adolescent Cancer Hospital of Barretos/SP. Method:Retrospective cohort study with charts review. The patients were divided in two groups, one submitted to low-intensity laser prophylaxis therapy after infusion of MTX and another group not submitted to prophylactic therapy. Results: The data obtained showed that preventive laser-therapy reduced the severity of oral mucositis with statistically significant results (p<0.001), corroborating the results found in the literature. Conclusion: The use of laser therapy is an important auxiliary therapy in the prevention and reduction of severity of oral mucositis in patients submitted to high doses of MTX, reducing the number of hospitalizations and delays in therapeutic protocol, which reduces costs and improves the patient prognosis.

Introducción: La quimioterapia, es uma de las formas de tratamiento de las neoplasias malignas, tiene su administración asociada a numerosas drogas siendo una de ellas el metotrexato (MTX), de alta toxicidad, responsable de numerosos factores agravantes para la salud y bienestar del paciente. Una de las principales complicaciones es la mucositis oral, manifestación clínica resultante del tratamiento oncológico que puede interferir en el tratamiento y cura. Objetivo: Evaluar, comparativamente, a través de um estudio retrospectivo, el efecto del láser preventivo em la aparición de la mucositis oral quimio inducida em pacientes com osteosarcoma no mestastásico sometido a altas dosis de MTX, bien como la intensidade de la mucositis oral, utilizando el láser preventivo después de los ciclos quimioterápicos que contiene el medicamento MTX en los pacientes antendidos en el Hospital del Cáncer Infantojuvenil de Barretos/SP. Método: Estudio de coorte con colección retrospectiva en prontuários. Los pacientes fueron divididos em dos grupos, uno sometido a terapia profiláctica con láser de baja intensidade después de la infusión de MTX y otro grupo no sometido a terapia profiláctica. Resultados: Los dados obtenidos mostraron que hubo una reducción en la severidad de la mucositis oral con el uso de la terapia láser preventiva, con resultados estáticamente significativos (p<0,001), corroborando los resultados encontrados em la literatura. Conclusión: El uso de la terapia con láser es una terapia auxiliar importante en la prevención y reducción de la severidad de la mucositis oral em pacientes sometidos a altas dosis de MTX, diminuendo el número de internaciones por mucositis y retrasos en el protocolo terapéutico, lo que reduce los gastos y mejora el pronóstico para el paciente.

Mechanism of the Notch signaling pathway in enhancing the efficacy of chemotherapy drugs in osteosarcoma / 中南大学学报(医学版)

Osteosarcoma is the most common malignant tumors of bone. Since 1970s, researchers had used chemotherapy drugs to treat osteosarcoma. However, multidrug resistance is a major adverse reaction that affects the efficacy of chemotherapy drugs, leading to the reduced survival rate of osteosarcoma patients. The Notch signaling pathway plays an important role in osteosarcoma proliferation, which affects tumor resistance by reducing intracellular drug accumulation, regulating epithelial-mesenchymal transition, dysregulating microRNA, disrupting the expression of apoptosis genes, and regulating tumor stem cells.

Avaliação do efeito antiproliferativo da apocinina e diapocinina em células de osteossarcoma humano / Evaluation of the antiproliferative effect of apocynin and diapocynin on human osteosarcoma cells

O osteossarcoma (OS) é o tumor maligno primário mais comum do tecido ósseo, caracterizado pela formação de osteócitos anormais. Apesar do avanço nas terapias convencionais (quimioterapia e retirada do tumor), essas não conseguem eliminar totalmente as células tumorais e impedir a progressão da doença. Recentemente, agentes derivados de fontes naturais ganharam considerável atenção por causa de sua segurança, eficácia e disponibilidade imediata. Nesse sentido, a apocinina, inibidor do complexo NADPH-oxidase, vem sendo estudada como agente antitumoral em alguns tipos de câncer como: pâncreas, próstata, pulmão e mama. Apocinina é um pró-fármaco e sua ação parece estar relacionada à sua conversão produzindo a diapocinina, a qual se mostrou mais efetiva do que a apocinina. Portanto, o objetivo desse estudo é avaliar, in vitro, o potencial antitumoral da apocinina e diapocinina em células de osteossarcoma humano. Para isso, foram utilizados osteoblastos humanos normais (HOb) e osteossarcoma humano imortalizadas (SaOS-2) tratados ou não com apocinina e diapocinina em diversas concentrações. Foram realizados os ensaios de viabilidade celular, alterações morfológicas, apoptose celular, produção de espécies reativas de oxigênio (EROs), formação de colônias, migração, invasão e expressão do fator indutor de hipóxia-1alfa (HIF-1). Também foram conduzidos ensaios para verificar a atividade de metaloproteinase de matriz (MMP) 2 e 9. Os resultados em SaOS-2 mostraram que o tratamento com apocinina nas concentrações de 1,5 e 3 mM; e diapocinina nas concentrações de 0,75 e 1,5 mM reduziram a viabilidade; aumentaram o número de células em apoptose e diminuíram a produção de EROs; sem causar danos às células HOb. Além disso, essas mesmas concentrações inibiram a migração e invasão celular; diminuíram a expressão de HIF-1; e reduziram a atividade de MMP-2 em SaOS-2. Considerando os resultados obtidos, concluímos que a apocinina e diapocinina podem atuar como possíveis moduladores de células tumorais, sendo que a diapocinina mostrou ser mais efetiva nos parâmetros testados.(AU)

Osteosarcoma (OS) is the most common primary malignant tumor of bone tissue, characterized by the formation of abnormal osteocytes. Despite advances in conventional therapies (chemotherapy and surgery) they cannot completely eliminate tumor cells and prevent the progression of the disease. Recently, agents derived from natural sources have achieved considerable attention because of their safety, efficacy and immediate availability of therapies. In this way, apocynin, an inhibitor of the NADPH-oxidase complex, has been studied as an antitumor agent in some types of cancer, such as pancreas, prostate, lung and breast. Apocynin is a prodrug and its action indicate to be related to its conversion to diapocynin, which has been shown to be more efficient than apocynin itself. Thus, the aim of this study is to evaluate, in vitro, the antitumor potential of apocynin and diapocynin in human osteosarcoma cells. For this, normal human osteoblasts (HOb) and immortalized human osteosarcoma cells (SaOS-2) were treated or no-treated with apocynin and diapocynin in various concentrations. Cell viability assay, morphological alterations, cellular apoptosis, reactive oxygen species (ROS) production, colony formation, migration, invasion and expression of hypoxia-inducible factor-1 alpha (HIF-1) were performed. We also performed assays to verify the activity of matrix metalloproteinase (MMP) 2 and 9. The results in SaOS-2 showed that treatment with apocynin at concentrations of 1,5 e 3 mM; and diapocynin at concentrations of 0,75 e 1,5 mM reduced cell viability; increased the number of cells in apoptosis and decreased the production of ROS; without damaging HOb cells. Moreover, these same concentrations inhibited cell migration and invasion; decreased HIF-1 expression; and reduced MMP 2 activity in SaOS-2. Considering the results, we suggest that apocynin and diapocynin may act as possible modulators of tumor cells, and diapocynin has been shown to be more effective.(AU)

Avaliação da atividade antitumoral de sais mesoiônicos no osteossarcoma: estudo in vitro / Evaluation of Mesoionic Salts antitumor activity in Osteosarcoma: In Vitro Study

O osteossarcoma é o tumor primário maligno mais comum do osso e acomete principalmente crianças e adolescentes. Cerca de 30 ­ 40% dos casos evoluem com metástases, o que diminui consideravelmente a sobrevida dos pacientes. O tratamento consiste em quimioterapia associada à cirurgia, porém, há poucas opções de medicamentos e os disponíveis provocam efeitos adversos. Além disso, determinou-se que 46,9% dos pacientes apresentam má resposta à quimioterapia pré-operatória. A identificação de novos compostos com aplicação terapêutica no osteossarcoma é fundamental para aumentar as possibilidades de tratamento dessa doença. Os sais mesoiônicos pertencem a uma classe de compostos heterocíclicos que possuem estruturas químicas que favorecem a interação com biomoléculas. A atividade antitumoral desses sais já foi verificada em diferentes tumores como hepatocarcinoma, melanoma e carcinossarcoma. Nesse contexto, o objetivo deste estudo foi avaliar o efeito antitumoral de sais mesoiônicos em células de osteossarcoma. Mediante o ensaio de redução de MTT, foi verificado que os sais MIC-F e MIC-NO2 reduziram a viabilidade relativa das células da linhagem de osteossarcoma MG-63, enquanto os sais MI-3,4-F e MI-F não foram capazes de reduzir a viabilidade das células após tratamento por 24 e 48 horas. Através da contagem das células com azul de tripan, foi verificado que o tratamento com os sais MIC-NO2 e MIC-F por 24 e 48 horas reduziu a viabilidade das células MG-63, sendo, portanto, citotóxicos. Por último, a análise de anexinaV e iodeto de propídeo por citometria de fluxo revelou que o tratamento com MIC-NO2 e MIC-F induziu morte celular por apoptose. Assim, dentre os quatro sais mesoiônicos avaliados neste estudo, apenas MIC-NO2 e MIC-F apresentaram efeitos citotóxicos em células de osteossarcoma MG-63 e, por isso, podem ser potenciais candidatos para o desenvolvimento de fármacos direcionados para o tratamento desta doença

Osteosarcoma is the most common primary bone malignancy of childhood and adolescence. About 30 - 40 % of the cases develop with metastases, which considerably decreases the survival of pacients. The current treatment includes cycles of preoperative chemotherapy followed by surgical resection and additional cycles of postoperative chemotherapy, but there are few options of chemotherapeutic agents and the available ones cause side effects. In addition, it was determined that 46.9% of patients present a poor response to preoperative chemotherapy. The identification of new compounds with promising application in osteosarcoma is relevant to the treatment of this disease. The mesoionic salts belong to a class of heterocyclic compounds with chemical structures that favor the interaction with biomolecules. The antitumor activity of these salts has already been verified in different tumors such as hepatocarcinoma, melanoma, and carcinosarcoma. The present study aimed to evaluate the antitumor effect of mesoionic salts in osteosarcoma cells. By the MTT reduction assay, it was found that the MIC-F and MIC-NO2 salts reduced the relative viability of the MG-63 osteosarcoma cells, while the MI-3,4-F and MI-F salts were not able to reduce the cell viability after treatment for 24 and 48 hours. By counting cells with trypan blue, it was found that treatment with the MIC-NO2 and MIC-F salts, for 24 and 48 hours, reduced the viability of MG-63 cells and were therefore cytotoxic. Finally, the analysis of annexin-V and propidium iodide by flow cytometry revealed that the treatment with MICNO2 and MIC-F induced cell death by apoptosis. Thus, among the four mesoionic salts evaluated in this study, only MIC-NO2 and MIC-F had cytotoxic effects on MG-63 osteosarcoma cells and, therefore, may be potential candidates for the development of drugs targeted to the treatment of this disease

MicroRNA-340-5p modulates cisplatin resistance by targeting LPAATβ in osteosarcoma

MicroRNAs (miRNAs) play an important role in drug resistance and modulate the efficiency of chemotherapy. A recent study indicated that miR-340 functions as a tumor suppressor in various types of cancer. However, the role of miR-340 in chemotherapy has not been reported yet. In this study, we found that miR-340 enhanced cisplatin (CDDP)-induced cell death. Induction of miR-340-5p expression decreased the IC50 of CDDP and increased the apoptosis of CDDP-resistant MG-63 and Saos-2 cells. Moreover, miR-340-5p decreased the accumulation of MRP1 and MDR1. We further explored the mechanism underlying the promoting effects of miR-340-5p on CDDP-induced cell death. We identified a potential target of miR-340 in the 3′ untranslated region of lysophosphatidic acid acyltransferase (LPAATβ) using the online program Targetscan (http://www.microrna.org). Luciferase reporter assays showed that miR-340 binds to the 3′UTR of LPAATβ. Enforced expression of miR-340-5p decreased the accumulation of LPAATβ in both MG-63 and Saos-2 cells. Silencing LPAATβ decreased the IC50 of CDDP and increased the apoptosis of CDDP-resistant MG-63 and Saos-2 cells, which is consistent with the effect of miR-340-5p on CDDP-induced cell death. Moreover, induced expression of LPAATβ compromised the effects of miR-340-5p on CDDP-induced cell death and accumulation of MRP1 and MDR1. Taken together, our data indicated that miR-340-5p enhanced the sensitivity to CDDP by targeting LPAATβ.

Osteosarcoma mandibular osteogénico / Mandibular osteogenic sarcoma

El osteosarcoma es una neoplasia maligna, poco frecuente, que se presenta de forma agresiva y sepuede originar en el hueso de la cavidad oral. Se caracteriza por la producción de osteoide tumoral(trabéculas óseas inmaduras) por parte de las células neoplásicas. Estos tumores suelen formarse en la región metafisiaria de los huesos largos de los miembros, en especial en el fémur y en la tibia. Se presenta el caso clínico de un paciente que concurre al servicio de Estomatología de la Escuela deOdontología, de la facultad de Ciencias de la Salud, Universidad Católica de Córdoba; masculino de 26 años de edad de nacionalidad peruana con diagnóstico clínico de osteosarcoma mandibular, el cual fue tratado con hemisección, quimioterapia y radioterapia en la zona mandibular sector posterior de lado izquierdo con colocación de una placa de titanio en la región.

Osteosarcoma is a malignant, rare and aggressive neoplasm that originates in the bone of the oralcavity. It is characterized by the production of tumor osteoid (immature bone trabeculae) by neoplasticcells. These tumors usually originate in metaphyseal region of long limb bones, especially in femurand tibia.Case report: 26-year-old peruvian male patient attending the Stomatology service at the School ofDentistry, Faculty of Health Sciences, Catholic University of Cordoba. The patient was clinically diagnosedwith mandibular osteosarcoma, treated with hemisection, chemotherapy, radiotherapy onmandibular zone posterior sector of left side and fixation of a titanium bone plate.

Avaliação do efeito do tratamento quimioterápico sobre eventos celulares relacionados com a metástase no osteossarcoma / Evaluation of chemotherapy effect on cellular events related to metastasis in osteosarcoma

O osteossarcoma é o tumor maligno primário mais frequente do osso e afeta principalmente os ossos dos membros inferiores de crianças e adolescentes. Embora o tratamento quimioterápico seja realizado com a combinação de fármacos, como doxorrubicina (DOX), cisplatina (CIS) e metotrexato (MTX), os pacientes desenvolvem com frequência metástases e recidiva. A transição epitéliomesenquimal (EMT) é um processo no qual as células epiteliais sofrem alterações bioquímicas, assumindo o fenótipo de células mesenquimais, que pela maior capacidade migratória e maior potencial de invasão está relacionada com o desenvolvimento de metástases. O objetivo geral deste estudo foi investigar a ocorrência de metástase em pacientes portadores de osteossarcoma e avaliar o efeito do tratamento quimioterápico in vitro sobre processos celulares relacionados com a metástase. Especificamente, analisamos (i) o momento da ocorrência da metástase em pacientes portadores de osteossarcoma em relação ao tratamento quimioterápico; (ii) a expressão de biomarcadores de EMT (E-caderina, claudina-1, zona ocludina (ZO-1), snail, N-caderina, ß-catenina, slug e vimentina) em células primárias de osteossarcoma isoladas de seis pacientes antes e após o tratamento quimioterápico e (iii) o efeito in vitro de agentes farmacológicos utilizados em protocolos de quimioterapia do osteossarcoma sobre a expressão dos biomarcadores de EMT e sobre a migração celular em culturas primárias estabelecidas a partir de amostras tumorais. As metástases ocorreram em 57,5% dos pacientes, sendo que dentre estes em 73,7% ocorreu na vigência do tratamento quimioterápico. A identidade óssea das culturas primárias foi conferida pela expressão de osteoprotegerina. Não houve diferença na expressão dos marcadores de EMT antes e depois da quimioterapia. Embora sem significância estatística, houve redução na expressão do marcador snail, E-caderina e ZO-1. Os marcadores mesenquimais (E-catenina, slug) e epitelial (claudina-1) permaneceram estáveis ou aumentaram ligeiramente (N-caderina e vimentina) depois da quimioterapia. No experimento in vitro a maior expressão de N-caderina e de vimentina ocorreu nas células tratadas simultaneamente com todos os agentes. A maior expressão de snail e slug foi observada na exposição isolada ao metotrexato. A expressão de Ecatenina não diferiu entre os diferentes tratamentos. Embora os resultados do presente estudo não nos permitam avançar no conhecimento sobre os mecanismos que controlam e regulam a evolução clínica do osteossarcoma, acreditamos que demos o passo inicial no sentido de definir marcadores, que potencialmente possam ser utilizados na caracterização biológica das diversas variantes do osteossarcoma e, desta forma, atuar com maior precisão no acompanhamento clínico e biológico da doença

Osteosarcoma is the most common primary malignant bone tumor and affects mainly the bones of the lower limbs in children and adolescents. Although chemotherapy is carried out with a combination of drugs such as doxorubicin (DOX), cisplatin (CIS) and methotrexate (MTX), patients often develop metastasis and recurrence. Epithelial-mesenchymal transition (EMT) is a process in which epithelial cells undergo biochemical changes, assuming the phenotype of mesenchymal cell with higher migration ability and increased potential for invasion and thus, to the development of metastasis. The aim of this study was to investigate the occurrence of metastasis in patients with osteosarcoma and evaluate the in vitro effect of chemotherapy on cellular processes related to metastasis. Specifically, we analyzed (i) the time of occurrence of metastasis in patients with osteosarcoma in relation to chemotherapy; (ii) expression of EMT biomarkers (E-cadherin, claudin-1, occludin zone (ZO-1), snail, N-cadherin, ß-catenin, slug and vimentin) in isolated osteosarcoma primary cells from six patients before and after chemotherapy and (iii) the in vitro effect of pharmacological agents used in chemotherapy protocols for osteosarcoma on the expression of EMT biomarkers and on cell migration both in primary cultures established from tumor samples. Metastasis occurred in 57.5% of patients and in 73.7% it took place during chemotherapy. Bone identity of primary cultures was conferred by osteoprotegerin expression. There was no difference in the expression of EMT markers before and after chemotherapy. Although not statistically significant, there was a reduction in the expression of markers snail, E-cadherin and ZO-1. The mesenchymal markers (ß-catenin, slug) and epithelial marker claudin-1 remained stable or increased slightly (N-cadherin and vimentin) after chemotherapy. In the in vitro experiment, most N-cadherin and vimentin expression occurred in cells treated simultaneously with all agents. The greatest expression of snail and slug was observed in isolated exposure to methotrexate. The ß-catenin expression did not differ between the different treatments. Although the results of this study do not allow us to advance in the knowledge about the mechanisms that control and regulate the clinical progression of osteosarcoma, we believe that we have taken the first step to define markers that may potentially be used in the biological characterization of the different variants of osteosarcoma and thus operate with greater precision in biological and clinical monitoring of the disease