RESUMO
Cancer of any type often can be described by an arrest, alteration or disruption in the normal development of a tissue or organ, and understanding of the normal counterpart's development can aid in understanding the malignant state. This is certainly true for osteosarcoma and the normal developmental pathways that guide osteoblast development that are changed in the genesis of osteogenic sarcoma. A carefully regulated crescendo-decrescendo expression of RUNX2 accompanies the transition from mesenchymal stem cell to immature osteoblast to mature osteoblast. This pivotal role is controlled by several pathways, including bone morphogenic protein (BMP), Wnt/ß-catenin, fibroblast growth factor (FGF), and protein kinase C (PKC). The HIPPO pathway and its downstream target YAP help to regulate proliferation of immature osteoblasts and their maturation into non-proliferating mature osteoblasts. This pathway also helps regulate expression of the mature osteoblast protein osteocalcin. YAP also regulates expression of MT1-MMP, a membrane-bound matrix metalloprotease responsible for remodeling the extracellular matrix surrounding the osteoblasts. YAP, in turn, can be regulated by the ERBB family protein Her-4. Osteosarcoma may be thought of as a cell held at the immature osteoblast stage, retaining some of the characteristics of that developmental stage. Disruptions of several of these pathways have been described in osteosarcoma, including BMP, Wnt/b-catenin, RUNX2, HIPPO/YAP, and Her-4. Further, PKC can be activated by several receptor tyrosine kinases implicated in osteosarcoma, including the ERBB family (EGFR, Her-2 and Her-4 in osteosarcoma), IGF1R, FGF, and others. Understanding these functions may aid in the understanding the mechanisms underpinning clinical observations in osteosarcoma, including both the lytic and blastic phenotypes of tumors, the invasiveness of the disease, and the tendency for treated tumors to ossify rather than shrink. Through a better understanding of the relationship between normal osteoblast development and osteosarcoma, we may gain insights into novel therapeutic avenues and improved outcomes.
Assuntos
Neoplasias Ósseas/metabolismo , Regulação Neoplásica da Expressão Gênica , Osteoblastos/metabolismo , Osteossarcoma/metabolismo , Transdução de Sinais/genética , Antineoplásicos/uso terapêutico , Proteínas Morfogenéticas Ósseas/genética , Proteínas Morfogenéticas Ósseas/metabolismo , Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Diferenciação Celular , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Via de Sinalização Hippo , Humanos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/patologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/patologia , Osteocalcina/genética , Osteocalcina/metabolismo , Osteossarcoma/tratamento farmacológico , Osteossarcoma/genética , Osteossarcoma/patologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Wnt/genética , Proteínas Wnt/metabolismo , beta Catenina/genética , beta Catenina/metabolismoRESUMO
INTRODUCTION: Infection control in patients with perforated peptic ulcers (PPU) commonly includes empiric antifungals (AF). We investigated the variation in the use of empiric AF and explored the association between their use and the subsequent development of organ space infection (OSI). METHODS: This was a secondary analysis of a multicenter, case-control study of patients treated for PPU at nine institutions between 2011 and 2018. Microbiology and utilization of empiric AF, defined as AF administered within 24 hours from the index surgery, were recorded. Patients who received empiric AF were compared with those who did not. The primary outcome was OSI and secondary outcome was OSI with growth of Candida spp. A logistic regression was used to adjust for differences between the two cohorts. RESULTS: A total of 554 patients underwent a surgical procedure for PPU and had available timing of AF administration. The median age was 57 years and 61% were male. Laparoscopy was used in 24% and omental patch was the most common procedure performed (78%). Overall, 239 (43%) received empiric AF. There was a large variation in the use of empiric AF among participating centers, ranging from 25% to 68%. The overall incidence of OSI was 14% (77/554) and was similar for patients who did or did not receive empiric AF. The adjusted OR for development of OSI for patients who received empiric AF was 1.04 (95% CI 0.64 to 1.70), adjusted p=0.86. The overall incidence of OSI with growth of Candida spp was 5% and was similar for both groups (adjusted OR 1.29, 95% CI 0.59 to 2.84, adjusted p=0.53). CONCLUSION: For patients undergoing surgery for PPU, the use of empiric AF did not yield any significant clinical advantage in preventing OSI, even those due to Candida spp. Use of empiric AF in this setting is unnecessary. STUDY TYPE: Original article, case series. LEVEL OF EVIDENCE: III.