sepantronium and Bone-Neoplasms

Canine osteosarcoma (OSA) is an aggressive and highly malignant primary bone tumor. Its poor survival outcome remains problematic despite recent advances in anti-cancer therapy, therefore highlighting the need for alternative treatment options or drug repositioning. The aim of this study was to determine if YM155, a small-molecule survivin inhibitor, potentiates the chemotherapeutic efficacy of etoposide against canine OSA in vitro and in vivo. In cell culture, YM155 enhanced the cytotoxic effect of etoposide against canine OSA cell lines; however, the molecular mechanism behind this effect was heterogeneous, as only one cell line had an elevated apoptotic level. In addition, this effect was not associated with survivin suppression in two of the cell lines. These results suggest that the molecular target of YM155 is not restricted to survivin alone. When tested on a murine xenograft model, the average tumor volume of the combination treatment group (YM155, 5 mg/kg, intraperitoneally, 5 consecutive days/week; and etoposide, 20 mg/kg, intraperitoneally, every 5 days) was 66% smaller than the control group, although this difference was not statistically significant (P=0.17). Further studies to improve the treatment protocol are necessary to confirm the findings of this study.

Topics: Animals; Antineoplastic Agents; Apoptosis; Bone Neoplasms; Cell Proliferation; Dog Diseases; Dogs; Drug Synergism; Etoposide; Humans; Imidazoles; Mice; Naphthoquinones; Osteosarcoma; Survivin; Xenograft Model Antitumor Assays

YM155, a novel small-molecule inhibitor of survivin, is known to exert antitumor effects on various cancers, including breast, prostate and lung cancer. However, there are few studies describing the inhibitory effect of YM155 on human osteosarcoma (OS) which highly expresses survivin. Here, we tested the effects of YM155 on OS cells by several in vitro experiments. It was found that YM155 inhibited cell proliferation, colony formation, migration and invasion, induced cell apoptosis, as well as increased caspase-3, -8 and -9 activity in the OS cell lines in a dose-dependent manner. We also found that YM155 suppressed Mcl-1 and survivin expression without affecting the expression of anti-apoptotic proteins X-linked inhibitor of apoptosis (XIAP) and Bcl-2. In addition, YM155 decreased phosphoinositide 3-kinase (PI3K) and AKT expression without effecting total PI3K and AKT in the OS cell lines, which contributed to suppression of OS tumor growth at least in part. In addition, YM155 also suppressed tumor growth in vivo, reducing the size of OS MG63 cell xenografts. Taken together, the findings revealed that YM155 suppresses the tumor growth of OS in vitro and in vivo, suggesting that YM155 has potential as a therapeutic agent for the treatment of OS.

Topics: Animals; Antineoplastic Agents; Bone Neoplasms; Cell Movement; Cell Proliferation; Gene Expression Regulation, Neoplastic; Humans; Imidazoles; Male; Mice; Naphthoquinones; Osteosarcoma; Xenograft Model Antitumor Assays

Chemoresistance is the principal reason for poor survival and disease recurrence in osteosarcoma patients. Survivin, a family member of the inhibitor of apoptosis proteins, plays an important role in inhibition of apoptosis. Survivin is expressed in a vast majority of human cancers, which is often correlated with poor prognosis in a wide variety of cancer patients. Furthermore, survivin expression is often related with chemoresistance in cancer cells, including osteosarcoma (OS). Here, we evaluated the therapeutic potential of YM155, a selective survivin suppressant alone and in combination with cisplatin using human OS models.. U-2 OS, SW1353, MG-63 cells were treated with YM155, and/or cisplatin, and cell viability, apoptosis, survivin protein expression levels were then evaluated. Furthermore, the efficacy of YM155 combined with cisplatin was further examined in established xenograft models.. YM155 was sufficient to induce spontaneous apoptosis of OS cells. Combination with YM155 significantly augmented the cytotoxicity of cisplatin in OS cells. Combination treatment of YM155 and cisplatin showed antiproliferative effects and induced a greater rate of apoptosis than the sum of the single-treatment rates and promoted tumor regression in established OS xenograft models.. Our findings provide evidence that YM155 could act as a survivin inhibitor on OS cells. Chemotherapeutic approaches using YM155 might enhance the benefit of the cisplatin in the treatment of OS cells. YM155 could be further developed as a potential therapeutic agent for the treatment of OS.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Bone Neoplasms; Cell Line, Tumor; Cell Survival; Cisplatin; Drug Resistance, Neoplasm; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Mice; Mice, Inbred ICR; Models, Animal; Naphthoquinones; Neoplasm Recurrence, Local; Osteosarcoma; Survivin; Xenograft Model Antitumor Assays

BIRC5 (Survivin), an inhibitor of apoptosis protein (IAP), is over-expressed in several human cancers and increased expression is associated with poor prognosis. The goal of the current study was to evaluate the role of BIRC5 in Ewing sarcoma (ES), the second most common pediatric bone sarcoma.. BIRC5 protein expression was determined in ES cell lines using Western Blot analysis. Functional role of survivin on growth and viability of ES cells was assessed by siRNA knockdown of BIRC5 and by using a small molecule inhibitor YM155. Immunohistochemical analysis for BIRC5 protein was performed on patient tumor samples using an anti-survivin antibody. The degree of BIRC5 protein expression was correlated with clinical parameters and patient outcome.. BIRC5 is over-expressed in a panel of ES cell lines. Gene silencing of BIRC5 in the ES cell line TC-71 decreases cell growth by more than 50% for each BIRC5 siRNA construct compared to non-silencing siRNA control constructs. YM155 also reduces ES cell growth and viability with an EC(50) ranging from 2.8 to 6.2 nM. BIRC5 protein is expressed in majority of the ES tumor samples with minimal expression in normal tissue (P < 0.005). Tumors with more than 50% expression are associated with worse overall survival than tumors with less than 50% expression (Hazard Ratio: 6.05; CI: 1.7-21.4; P = 0.04).. BIRC5 is over-expressed in ES cell lines and tumor samples. Further, it plays an important role in cell growth and viability in vitro. Higher degree of expression in patients is an independent poor prognostic factor.

Topics: Adolescent; Adult; Apoptosis; Biomarkers; Bone Neoplasms; Cell Line, Tumor; Cell Proliferation; Child; Child, Preschool; Female; Humans; Imidazoles; Inhibitor of Apoptosis Proteins; Male; Naphthoquinones; Prognosis; Sarcoma, Ewing; Survivin