Phase 1 clinical trials for sarcomas: the cutting edge. Curr Opin Oncol. 2011;23:352-360. [PMID: 21519259 DOI: 10.1097/cco.0b013e3283477a94]

Advancements in Osteosarcoma Therapy: Overcoming Chemotherapy Resistance and Exploring Novel Pharmacological Strategies

Osteosarcoma is recognized as the most prevalent primary bone malignancy, primarily affecting children and adolescents. It is characterized by its aggressive behavior and high metastatic potential, which often leads to poor patient outcomes. Despite advancements in surgical techniques and chemotherapy regimens, the prognosis for patients with osteosarcoma remains unsatisfactory, with survival rates plateauing over the past few decades. A significant barrier to effective treatment is the development of chemotherapy resistance, which complicates the management of the disease and contributes to high rates of recurrence. This review article aims to provide a comprehensive overview of recent advancements in osteosarcoma therapy, particularly in overcoming chemotherapy resistance. We begin by discussing the current standard treatment modalities, including surgical resection and conventional chemotherapy agents such as methotrexate, doxorubicin, and cisplatin. While these approaches have been foundational in managing osteosarcoma, they are often limited by adverse effects and variability in efficacy among patients. To address these challenges, we explore novel pharmacological strategies that aim to enhance treatment outcomes. This includes targeted therapies focusing on specific molecular alterations in osteosarcoma cells and immunotherapeutic approaches designed to harness the body's immune system against tumors. Additionally, we review innovative drug delivery systems that aim to improve the bioavailability and efficacy of existing treatments while minimizing toxicity. The review also assesses the mechanisms underlying chemotherapy resistance, such as drug efflux mechanisms, altered metabolism, and enhanced DNA repair pathways. By synthesizing current research findings, we aim to highlight the potential of new therapeutic agents and strategies for overcoming these resistance mechanisms. Ultimately, this article seeks to inform future research directions and clinical practices, underscoring the need for continued innovation in treating osteosarcoma to improve patient outcomes and survival rates.

Activity of pazopanib in EWSR1-NFATC2 translocation-associated bone sarcoma

Pazopanib is a multi-kinase inhibitor that is currently approved for treatment of advanced renal cell carcinoma and chemotherapy-refractory soft tissue sarcoma. In this case report, we discuss the case of a patient with a EWSR1-NFATC2 fusion positive bone sarcoma who had exceptional tumor control through using pazopanib and surgery for an overall duration exceeding 5 years. We also review the literature on EWSR1-NFATC2 translocation-associated sarcomas and use of pazopanib in bone sarcomas.

Impact of Biomarker-Matched Therapies on Outcomes in Patients with Sarcoma Enrolled in Early-Phase Clinical Trials (SAMBA 101)

PURPOSE

Developing new therapeutics for any of the more than 100 sarcoma subtypes presents a challenge. After progression from standard therapies, patients with sarcoma may be referred for enrollment in early-phase trials. This study aimed to investigate whether enrollment in biomarker-matched early-phase clinical trials leads to better outcomes for patients with advanced sarcoma.

EXPERIMENTAL DESIGN

In this retrospective analysis, investigational treatment characteristics and longitudinal survival outcomes were analyzed in patients with biopsy-confirmed sarcoma enrolled in early-phase trials at MD Anderson Cancer Center from May 2006 to July 2021.

RESULTS

Five hundred eighty-seven patients were included [405 soft tissue, 122 bone, 60 gastrointestinal stromal tumor (GIST); median of three prior lines of therapy]. Most common subtypes were leiomyosarcoma (17.2%), liposarcoma (14.0%), and GIST (10.2%). Molecular testing was available for 511 patients (87.1%); 221 patients (37.6%) were treated in matched trials. Overall response rate was 13.1% matched compared with 4.9% in unmatched (P < 0.001); the clinical benefit rate at 6 months was 43.9% vs. 19.9% (P < 0.001). Progression-free survival was longer for patients in matched trials (median, 5.5 vs. 2.4 months; P < 0.001), and overall survival was also superior for patients in matched trials (median, 21.5 vs. 12.3 months; P < 0.001). The benefit of enrollment in matched trials was maintained when patients with GIST were excluded from the analysis.

CONCLUSIONS

Enrollment in biomarker-matched early-phase trials is associated with improved outcomes in heavily pretreated patients with metastatic sarcoma. Molecular testing of tumors from patients with advanced sarcoma and enrollment in matched trials is a reasonable therapeutic strategy.

Examining Stripes on a Herd of Zebras: Impact of Genomic Matching for Ultrarare Sarcomas in Phase 1 Clinical Trials (SAMBA 102)

PURPOSE

Recently, the Connective Tissue Oncology Society published consensus guidelines for recognizing ultrarare sarcomas (URS), defined as sarcomas with an incidence ≤1 per 1,000,000. We assessed the outcomes of 56 patients with soft tissue, and 21 with bone sarcomas, enrolled in Phase 1 trials.

EXPERIMENTAL DESIGN

In this Sarcoma-Matched Biomarker Analysis (SAMBA-102 study), we reviewed records from patients on Phase 1 trials at the University of Texas MD Anderson Cancer Center between January 2013 and June 2021.

RESULTS

Among 587 sarcomas, 106 (18.1%) were classified as URS. Fifty (47%) were male, and the median age was 44.3 years (range, 19-82). The most common subtypes were alveolar soft part sarcoma (ASPS), chordoma, dedifferentiated chondrosarcoma, and sclerosing epithelioid fibrosarcoma. Compared with common sarcomas, median OS was similar 16.1 months [95% confidence interval (CI), 13.6-17.5] versus 16.1 (95% CI, 8.2-24.0) in URS (P = 0.359). Objective response to treatment was higher in URS 13.2% (n = 14/106) compared with common sarcomas 6.9% (n = 33/481; P = 0.029). Median OS for those treated on matched trials was 27.3 months (95% CI, 1.9-52.7) compared with 13.4 months (95% CI, 6.3-20.6) for those not treated on matched trials (P = 0.291). Eight of 33 (24%) molecularly matched treatments resulted in an objective response, whereas 6 of 73 unmatched treatments (8.2%) resulted in an objective response (P = 0.024). Clinical benefit rate was 36.4% (12/33) in matched trials versus 26.0% (19/73) in unmatched trials (P = 0.279).

CONCLUSIONS

The results demonstrate the benefit of genomic selection in Phase 1 trials to help identify molecular subsets likely to benefit from targeted therapy.

MicroRNA-761 targets FGFR1 to suppress the malignancy of osteosarcoma by deactivating PI3K/Akt pathway

Purpose

MicroRNA-761 (miR-761) has been reported to be deregulated in many types of human cancers and play important roles in cancer genesis and progression. However, the biological roles of miR-761 in osteosarcoma (OS) and the underlying mechanisms remain largely unknown.

Methods

The expression of miR-761 in OS tissues and cell lines was analyzed using RT-qPCR. A series of gain-of-function tests were performed, and status of malignancy was evaluated on basis of proliferation, migration, invasion, and apoptosis using different assays to determine the regulatory roles of miR-761 in OS cells in vivo and in vitro. Notably, the mechanisms underlying the action of miR-761 in the pathogenesis of OS were investigated using bioinformatic analysis, luciferase reporter assay, RT-qPCR and Western blotting.

Results

The results showed that miR-761 expression was decreased in OS tissues and cell lines and is closely correlated with clinical stage and distant metastasis in OS patients. Patients with OS having low miR-761 expression showed worse prognosis compared to OS patients with high miR-761 expression. Restoring the miR-761 expression level decreased OS cell proliferation, migration, and invasion in vitro; promoted cell apoptosis in vitro; and impaired tumor growth in vivo. In addition, fibroblast growth factor receptor 1 (FGFR1) was found as a direct target gene of miR-761 in OS cells. Furthermore, silencing FGFR1 expression stimulated the tumor-suppressing roles of miR-761 upregulation in OS cells, whereas the activity of miR-761 overexpression in OS cells was abolished by the restoration of FGFR1 expression. Moreover, restoration of miR-761 expression deactivated the PI3K/Akt pathway in vitro and in vivo.

Conclusion

These results suggest that miR-761 plays anti-cancer roles in OS by directly targeting FGFR1 and deactivating the PI3K/Akt pathway. The newly identified miR-761/FGFR1/PI3K/Akt pathway partially illustrates the mechanism of OS pathogenesis and presents a novel candidate therapeutic target for antitumor therapy.

Precision Oncology in Sarcomas: Divide and Conquer

Sarcomas are a heterogeneous group of rare malignancies that exhibit remarkable heterogeneity, with more than 50 subtypes recognized. Advances in next-generation sequencing technology have resulted in the discovery of genetic events in these mesenchymal tumors, which in addition to enhancing understanding of the biology, have opened up avenues for molecularly targeted therapy and immunotherapy. This review focuses on how incorporation of next-generation sequencing has affected drug development in sarcomas and strategies for optimizing precision oncology for these rare cancers. In a significant percentage of soft tissue sarcomas, which represent up to 40% of all sarcomas, specific driver molecular abnormalities have been identified. The challenge to evaluate these mutations across rare cancer subtypes requires the careful characterization of these genetic alterations to further define compelling drivers with therapeutic implications. Novel models of clinical trial design also are needed. This shift would entail sustained efforts by the sarcoma community to move from one-size-fits-all trials, in which all sarcomas are treated similarly, to divide-and-conquer subtype-specific strategies.

miR-885-5p suppresses osteosarcoma proliferation, migration and invasion through regulation of β-catenin

MicroRNAs (miRs) have been reported to serve key roles in cancer. To investigate the function of miR-885-5p in osteosarcoma, the expression levels of miR-885-5p were analyzed in 85 osteosarcoma tissue samples and adjacent non-cancerous tissue samples, using reverse transcription-quantitative polymerase chain reaction analysis. It was demonstrated that miR-885-5p was downregulated in osteosarcoma tissues and cell lines. Notably, the expression level of miR-885-5p was closely associated with tumor size, Tumor-Node-Metastasis stage and lymph node metastasis. Additionally, low expression levels of miR-885-5p also predicted a poor prognosis of osteosarcoma. To further decipher the roles of miR-885-5p in osteosarcoma, it was determined that β-catenin, a key component of the Wnt signaling pathway, was a target of miR-885-5p. Furthermore, several functional experiments, including a colony formation assay, CCK-8 assay, wound healing assay and Transwell invasion assay, revealed that miR-885-5p suppressed cell proliferation, migration and invasion through inhibition of β-catenin. The results of the present study provide a novel insight into the molecular roles of miR-885-5p in osteosarcoma.

Clinical genomic profiling to identify actionable alterations for investigational therapies in patients with diverse sarcomas

Background

There are currently no United States Food and Drug Administration approved molecularly matched therapies for sarcomas except gastrointestinal stromal tumors. Complicating this is the extreme diversity, heterogeneity, and rarity of these neoplasms. Few therapeutic options exist for relapsed and refractory sarcomas. In clinical practice many oncologists refer patients for genomic profiling hoping for guidance on treatment options after standard therapy. However, a systematic analysis of actionable mutations has yet to be completed. We analyzed genomic profiling results in patients referred to MD Anderson Cancer Center with advanced sarcomas to elucidate the frequency of potentially actionable genomic alterations in this population.

Methods

We reviewed charts of patients with advanced sarcoma who were referred to investigational cancer therapeutics department and had CLIA certified comprehensive genomic profiling (CGP) of 236 or 315 cancer genes in at least 50ng of DNA. Actionable alterations were defined as those identifying anti-cancer drugs on the market, in registered clinical trials, or in the Drug-Gene Interaction Database.

Results

Among the 102 patients analyzed median age was 45.5 years (range 8-76), M: F ratio 48:54. The most common subtypes seen in our study were leiomyosarcoma (18.6%), dedifferentiated liposarcoma (11%), osteosarcoma (11%), well-differentiated liposarcoma (7%), carcinosarcoma (6%), and rhabdomyosarcoma (6%). Ninety-five out of 102 patients (93%) had at least one genomic alteration identified with a mean of six mutations per patient. Of the 95 biopsy samples with identifiable genomic alterations, the most commonly affected genes were TP53 (31.4%), CDK4 (23.5%), MDM2 (21.6%), RB1 (18.6%), and CDKN2A/B (13.7%). Notable co-segregating amplifications included MDM2-CDK4 and FRS2-FGF. Sixteen percent of patients received targeted therapy based on CGP of which 50% had at least stable disease.

Conclusions

Incorporating CGP into sarcoma management may allow for more precise diagnosis and sub-classification of this diverse and rare disease, as well as personalized matching of patients to targeted therapies such as those available in basket clinical trials.

Validation of prognostic scoring and assessment of clinical benefit for patients with bone sarcomas enrolled in phase I clinical trials

Background

We sought to validate the Royal Marsden Hospital (RMH) and MD Anderson Cancer Center (MDACC) prognostic scoring systems for the selection of bone sarcoma patients for phase I clinical trials and to identify additional risk factors related to survival.

Patients and Methods

We retrospectively reviewed the baseline characteristics and outcomes of 92 bone sarcoma patients who were referred to MDACC's Phase I Clinical Trials Program.

Results

Ninety-two patients with Ewing sarcoma (N = 47), osteosarcoma (N = 22), chondrosarcoma (N = 16), and other tumors (N = 7) were evaluated; 78 were enrolled in at least 1 of 43 different phase I trials. The median overall survival (OS) was 8.8 months (95% confidence interval [CI] = 6.8–13.7 months). Independent factors that predicted shorter survival were male sex, >2 metastatic sites, >3 previous therapies, hemoglobin level <10.5 g/dL, platelet count >200 x10³/L, creatinine level ≥1.3 mg/dL, and lactate dehydrogenase level >ULN. Patients with good RMH scores (0-1) had longer OS than patients with poor RMH scores (2-3) (HR = 5.8, 95% CI = 2.9–11.0; P < 0.0001), as did patients with low MDACC scores (0-1) as compared to patients with higher MDACC scores (2–4) (HR = 3.2, 95% CI = 1.9–5.6; P < 0.0001).

Conclusion

The RMH prognostic score can be used to predict the OS of bone cancer patients referred for phase I trials. The MDACC score added no value to the RMH score and therefore does not have a role in assessment of patients with bone tumors. Patients with advanced bone sarcomas should be considered for phase I trials.

Characteristics and outcomes of patients with advanced sarcoma enrolled in early phase immunotherapy trials

Background

Immunotherapies, specifically those based on immune checkpoint inhibitors, have shown promising activity in multiple tumor types. Other than mifamurtide (MEPACT®) for osteosarcoma approved by European Medicines Agency, there are no approved immunotherapies for sarcomas.

Methods

We analyzed medical records of patients with advanced sarcoma who were referred to Phase 1 clinic at MD Anderson and received an immunotherapy (checkpoint inhibitors, vaccines, or cytokine based therapies). Clinical parameters including demographics, clinical history, toxicity, and response were abstracted.

Results

Among 50 patients enrolled in immunotherapy trials (Bone 10; Soft-tissue 40) we found 14 different subtypes of sarcomas. Royal Marsden Hospital (RMH) prognostic score was <2 (86%). Performance status (PS) was 0–1 in 48 patients (96%); median number of prior therapies was 3 (0–12). Immunotherapy consisted of checkpoint inhibitors (82%: PD1 = 7, PD-L1 = 11, CTLA4 = 22, other = 1) of which 42% were combinations, as well as vaccines (14%), and cytokines (4%). Median overall survival (OS) was 13.4 months (11.2 months: not reached). Median progression free survival (PFS) was 2.4 months (95% CI = 1.9–3.2 months). Best response was partial response (PR) in 2 patients with alveolar soft part sarcoma (ASPS) and stable disease (SD) in 11 patients (3 GIST, 3 liposarcomas (2 DDLS, 1 WDLS), 2 ASPS, 2 leiomyo, 1 osteo). PFS was 34% (23%, at 50%) at 3 months, 16% (8%, 30%) at 6 months, and 6% (2%, 20%) at 1 year. Pseudo-progression followed by stable disease was observed in 2 patients (4%). Grade 3/4 adverse events included rash (10%), fever (6%), fatigue (6%), and nausea/vomiting (6%).

Conclusion

Immunotherapies were well tolerated in advanced sarcoma patients enrolled in trials. All four ASPS patients had clinical benefit with checkpoint inhibitors and this was the only subtype experiencing partial response. Further evaluation of checkpoint inhibitors in ASPS is warranted.

Outcomes of patients with sarcoma enrolled in clinical trials of pazopanib combined with histone deacetylase, mTOR, Her2, or MEK inhibitors

Pazopanib is US FDA approved for the treatment of advanced soft tissue sarcomas. All patients with this disease ultimately develop resistance to therapy. Mechanisms of resistance include activation of the mTOR, histone deacetylase (HDAC), MAPK, and ERBB4 pathways. We hypothesized that combining pazopanib with other targeted agents inhibiting these pathways would increase response rates. We retrospectively evaluated the safety and efficacy of pazopanib plus vorinostat, everolimus, lapatinib or trastuzumab, and MEK inhibitor in patients with advanced sarcoma. The Cancer Geneome Atlas (TCGA) data was analyzed for HDAC, PI3K, HER2, and MAPK/RAS/RAF gene alterations from sarcoma TCGA. Of the 44 advanced sarcoma patients in these trials, 27 (61%) were male; 18 (41%) had bone sarcoma, and 26 (59%) had soft tissue sarcoma. Best response was partial response (PR) in four patients [(overall response rate (ORR) = 9%, 95% confidence interval [CI] 3% to 22%)]. The median progression-free survival (PFS) for all patients was 9.6 weeks (95% CI 8.0 to 15.7 weeks). Analysis of TCGA data revealed HDAC, PI3K, HER2, and MAPK/RAS/RAF gene alterations in 112/243 (46%) of patients predominantly HDAC1-11 (41%) alterations. Pazopanib combinations did demonstrate safety in combination with other agents. TCGA data suggests further evaluation of epigenetic pathway inhibitors in sarcoma.

TRIM37 promotes tumor cell proliferation and drug resistance in pediatric osteosarcoma

Osteosarcoma (OS) is among the most frequently occurring bone tumors, particularly in children. Clinical treatment of OS is limited due to several factors including resistance to chemotherapy drugs and metastasis, and the underlying molecular mechanisms remain unclear. In the present study, tripartite motif containing 37 (TRIM37) expression levels were upregulated in tumor samples and associated with the development of drug resistance in OS. Furthermore, chemotherapy drug treatment (doxorubicin, cisplatin and methotrexate) induced TRIM37 expression in OS cells in vitro. TRIM37 mRNA and protein were upregulated in 41 pediatric osteosarcoma clinical specimens. To further elucidate the effect of TRIM37, gain and loss-of-function analysis was performed. Overexpression of TRIM37 induced cell proliferation and drug resistance ability of OS cells, whilst TRIM37 knockdown suppressed cell growth rate and restored chemosensitivity. TRIM37-regulated genes were subsequently analyzed by expression microarray and gene set enrichment analysis. Using the Wnt/β-catenin inhibitor XAV-939, the present study demonstrated that TRIM37-induced chemoresistance is partially dependent on the activation of the Wnt/β-catenin signaling pathway. Collectively, the results of the present study suggest that TRIM37 may have a key role in the development of OS and in the ability for the cells to acquire drug resistance, thus it may be a novel target for the treatment of OS.

Phase Ib/II Study of the Safety and Efficacy of Combination Therapy with Multikinase VEGF Inhibitor Pazopanib and MEK Inhibitor Trametinib In Advanced Soft Tissue Sarcoma

Purpose: Pazopanib, a multireceptor tyrosine kinase inhibitor targeting primarily VEGFRs1-3, is approved for advanced soft tissue sarcoma (STS) and renal cell cancer. Downstream of VEGFR, trametinib is an FDA-approved MEK inhibitor used for melanoma. We hypothesized that vertical pathway inhibition using trametinib would synergize with pazopanib in advanced STS.Experimental Design: In an open-label, multicenter, investigator-initiated National Comprehensive Cancer Network (NCCN)-sponsored trial, patients with metastatic or advanced STS received pazopanib 800 mg and 2 mg of trametinib continuously for 28-day cycles. The primary endpoint was 4-month progression-free survival (PFS). Secondary endpoints were overall survival, response rate, and disease control rate.Results: Twenty-five patients were enrolled. The median age was 49 years (range, 22-77 years) and 52% were male. Median PFS was 2.27 months [95% confidence interval (CI), 1.9-3.9], and the 4-month PFS rate was 21.1% (95% CI, 9.7-45.9), which was not an improvement over the hypothesized null 4-month PFS rate of 28.3% (P = 0.79). Median overall survival was 9.0 months (95% CI, 5.7-17.7). A partial response occurred in 2 (8%) of the evaluable patients (95% CI, 1.0-26.0), one with PIK3CA E542K-mutant embryonal rhabdomyosarcoma and another with spindle cell sarcoma. The disease control rate was 14/25 (56%; 95% CI, 34.9-75.6). The most common adverse events were diarrhea (84%), nausea (64%), fatigue (56%), and hypertension (52%).Conclusions: The combination of pazopanib and trametinib was tolerable without indication of added activity of the combination in STS. Further study may be warranted in RAS/RAF aberrant sarcomas. Clin Cancer Res; 23(15); 4027-34. ©2017 AACR.

Evaluation of Novel Targeted Therapies in Aggressive Biology Sarcoma Patients after progression from US FDA approved Therapies

Prognosis of patients with advanced sarcoma after progression from FDA approved therapies remains grim. In this study, clinical outcomes of 100 patients with advanced sarcoma who received treatment on novel targeted therapy trials were evaluated. Outcomes of interest included best response, clinical benefit rate, progression-free survival (PFS) and overall survival (OS). Median patient age was 48 years (range 14-80). Patients had received a median of 2 prior lines of systemic treatment. Phase I treatments were anti-VEGF-based (n = 45), mTOR inhibitor-based (n = 15), and anti-VEGF + mTOR inhibitor-based (n = 17) or involved other targets (n = 23). Best responses included partial response (n = 4) and stable disease (n = 57). Clinical benefit rate was 36% (95% confidence interval 27-46%). Median OS was 9.6 months (95% Confidence Interval 8.1-14.2); median PFS was 3.5 months (95% Confidence Interval 2.4-4.7). RMH prognostic score of 2 or 3 was associated with lower median OS (log-rank p-value < 0.0001) and PFS (log-rank p-value 0.0081). Receiving cytotoxic chemotherapy as part of phase I trial was also associated with shorter median OS (log-rank p-value 0.039). Patients with advanced sarcoma treated on phase I clinical trials had a clinical benefit rate of 36% and RMH score predicted survival.

Response to Early Treatment Evaluated with 18F-FDG PET and PERCIST 1.0 Predicts Survival in Patients with Ewing Sarcoma Family of Tumors Treated with a Monoclonal Antibody to the Insulinlike Growth Factor 1 Receptor

The aim of this study was to assess the prognostic and predictive value of early quantitative (18)F-FDG PET to monitor therapy with an antibody to the insulinlike growth factor 1 receptor (IGF-1R antibody) in patients with Ewing sarcoma family of tumors (ESFT).

METHODS

(18)F-FDG PET images at baseline and approximately 9 d after initiation of IGF-1R antibody therapy in 115 patients with refractory or relapsed ESFT were prospectively obtained as part of the Sarcoma Alliance for Research through Collaboration trial. Responses were centrally evaluated by PERCIST 1.0 in 93 patients. The 9-d PET responses were correlated to overall survival (OS), progression-free survival (PFS), and clinical benefit after 6 wk of therapy based on clinical observation and CT response by World Health Organization anatomic criteria.

RESULTS

The median OS was 8.1 mo (95% confidence interval, 6.4-10.0 mo). When PERCIST was used, patients with progressive metabolic disease showed shorter OS (median, 4.7 mo) than patients without progression (median, 10.0 mo; P = 0.001). Progressive metabolic disease on day-9 PET was associated with a significantly higher risk of death (hazard ratio, 2.8; 95% confidence interval, 1.5-5.5). Changes in (18)F-FDG uptake after 9 d of therapy had an area under the curve of receiver-operating characteristic of 0.71 to predict 1-y OS. The area under the curve was 0.63 to predict progression at 3 mo and 0.79 to predict clinical benefit after 6 wk of therapy.

CONCLUSION

Treatment response by quantitative (18)F-FDG PET assessed by PERCIST 1.0 as early as 9 d into IGF-1R antibody therapy in patients with ESFT can predict the OS, PFS, and clinical response to therapy.

GRM4 gene polymorphism is associated with susceptibility and prognosis of osteosarcoma in a Chinese Han population

Osteosarcoma (OS), the most common primary bone malignancy, occurs primarily in adolescents and young adults. In earlier genome-wide association studies, rs7591996, rs10208273, rs17206779 and rs1906953 were identified as candidate loci for OS in Caucasians but the association of these single-nucleotide polymorphisms (SNPs) with OS in a Chinese Han population remains unknown. We measured the frequency of these four variants in a Chinese Han population to better understand the genetic etiology of OS. Polymerase chain reaction sequencing was used to detect the genotypes of four candidate SNPs in peripheral blood samples collected from 168 OS patients and 216 healthy controls. Logistic regression models were used to estimate the odds ratios and 95 % confidence intervals. We found rs1906953 in the glutamate receptor metabotropic 4 (GRM4) gene was associated significantly with OS in our Chinese Han population; as with the other SNPs, however, no statistically significant difference was detected. Further analysis showed the association between rs1906953 and OS was independent of gender and age. The rs1906953 locus was not associated with Enneking stages or tumor location; however, it was associated significantly with OS metastasis and prognosis. The GRM4 gene polymorphism was associated with the susceptibility and metastasis of OS in a Chinese Han population.

Inhibiting phosphorylation of the oncogenic PAX3-FOXO1 reduces alveolar rhabdomyosarcoma phenotypes identifying novel therapy options

Patients with translocation-positive alveolar rhabdomyosarcoma (ARMS), an aggressive childhood tumor primarily characterized by the PAX3-FOXO1 oncogenic fusion protein, have a poor prognosis because of lack of therapies that specifically target ARMS tumors. This fact highlights the need for novel pharmaceutical interventions. Posttranslational modifications such as phosphorylation are becoming attractive biological targets for the development of such interventions. Along these lines, we demonstrated that PAX3-FOXO1 is phosphorylated at three specific sites and that its pattern of phosphorylation is altered relative to wild-type Pax3 throughout early myogenesis and in ARMS tumor cells. However, little work has been performed examining the effect of directly inhibiting phosphorylation at these sites on ARMS development. To address this gap in knowledge, we used small molecule inhibitors or mutational analysis to specifically inhibit phosphorylation of PAX3-FOXO1 to investigate how altering phosphorylation of the oncogenic fusion protein affects ARMS phenotypes. We found that inhibiting the phosphorylation of PAX3-FOXO1 at Ser201 significantly reduced migration, invasion and proliferation in two independent ARMS tumor cell lines. Further, we found that inhibition of phosphorylation at Ser205 also decreased proliferation and anchorage-independent growth. Consistent with these in vitro results, we demonstrate for the first time that PAX3-FOXO1 is phosphorylated at Ser201 and Ser205 in a primary tumor sample and in tumor cells actively invading the surrounding normal tissue. This report is the first to demonstrate that the direct inhibition of PAX3-FOXO1 phosphorylation reduces ARMS tumor phenotypes in vitro and that these phosphorylation events are present in primary human ARMS tumors and invading tumor cells. These results identify phosphorylation of PAX3-FOXO1, especially at Ser201, as a novel biological target that can be explored as a promising avenue for ARMS therapies.

Clinical next generation sequencing of pediatric-type malignancies in adult patients identifies novel somatic aberrations

Pediatric malignancies in adults, in contrast to the same diseases in children are clinically more aggressive, resistant to chemotherapeutics, and carry a higher risk of relapse. Molecular profiling of tumor sample using next generation sequencing (NGS) has recently become clinically available. We report the results of targeted exome sequencing of six adult patients with pediatric-type malignancies : Wilms tumor(n=2), medulloblastoma(n=2), Ewing's sarcoma( n=1) and desmoplastic small round cell tumor (n=1) with a median age of 28.8 years. Detection of druggable somatic aberrations in tumors is feasible. However, identification of actionable target therapies in these rare adult patients with pediatric-type malignancies is challenging. Continuous efforts to establish a rare disease registry are warranted.

Prospects and pitfalls of personalizing therapies for sarcomas: from children, adolescents, and young adults to the elderly

Sarcomas are a heterogeneous class of tumors that affect all ages, from children, adolescents, and young adults to the elderly. Within this panoply of tumor subtypes lies the opportunity to bring to bear a vision of personalized medicine in which the fast-paced evolution from the "one gene, one test, one drug" approach to a comprehensive "panomic," multiplex, multianalyte method coupled with advances in bioinformatics platforms can unravel the biology of this disease. The increasingly enlarging repertoire of novel agents provides innumerable prospects in precision medicine. Personalized therapy covers the entire spectrum of cancer care, from risk factor assessment through prevention, risk reduction, therapy, follow-up after therapy, and survivorship care. Challenges remain in implementing the science of precision medicine in the clinic, including providing comprehensive multidisciplinary care and overcoming regulatory and economic hurdles, which must be facilitated within the collaborative framework of academia, industry, federal regulators, and third-party payers.

PIK3CA and AKT gene polymorphisms in susceptibility to osteosarcoma in a Chinese population

PURPOSE

To explore the association between PIK3CA and AKT single nucleotide polymorphisms(SNP) and osteosarcoma susceptibility.

METHODS

TaqMan polymerase chain reaction(PCR) was used to detect the genotypes of SNPs (rs7646409, rs6973569 and rs9866361) in peripheral blood samples from 59 patients with osteosarcoma and from 63 healthy controls. Unconditional logistic regression was used to analyze the correlation between SNPs and osteosarcoma risk.

RESULTS

No statistically significant difference was found between osteosarcoma patients and healthy controls in the genotype of AKT rs6973569 (P = 0.7). However, after stratified analysis, the genotype AA of AKT rs6973569 carried a higher risk of osteosarcoma metastasis (OR:2.94, 95%CL:1.00-8.59); the difference of rs7646409 genotype distributions between the case and control groups was statistically significant (P = 0.032). Taking genotype TT as a reference, the risk of osteosarcoma increased three fold in patients with genotype CC (OR:3.47, 95%CL:1.26-9.56). A statistically significant difference was found between the alleles C and T (P=0.005). Further analysis showed that the risk factor was more pronounced in male patients with Enneking's stage IIB and osteoblastic osteosarcoma. PIK3CA rs9866361 did not fit Hardy-Weinberg equilibrium (P < 0.05).

CONCLUSIONS

Genotype CC in locus PIK3CA rs7646409 may increase the risk of osteosarcoma in the Chinese population.

Endothelin-1 gene polymorphisms and risk of chemoresistant pediatric osteosarcoma

BACKGROUND

Osteosarcoma (OS) is the most common childhood bone cancer. Chemoresistance is the principal reason for poor survival and disease recurrence in OS patients, and ET-1 reportedly plays an important role in the development of chemoresistance in OS cells. In the present study, we for the first time explored the association of endothelin-1 (ET-1) SNPs and haplotypes with the risk of chemoresistant pediatric OS.

PROCEDURE

We genotyped three SNPs (rs1800541, rs2070699, and rs5370) in the ET-1 gene in a case-control study, using 350 pairs of age, sex, and tumor location and stage matched pediatric patients with OS. Patients who showed <90% tumor necrosis after neochemotherapy were defined as poor responders (cases), and those who showed ≥90% tumor necrosis were defined as good responders (controls).

RESULTS

The G allele at rs1800541 and the G allele at rs2070699 were associated with reduced and increased risk of chemoresistant OS, respectively. The rs1800541-rs2070699 haplotypes TG and GT were respectively associated with increased (P = 0.012; adjusted OR, 1.82; 95% CI, 1.10-5.65) and reduced (P = 0.009; adjusted OR, 0.25; 95% CI, 0.14-0.84) risk of chemoresistant OS. The TG and the GT haplotypes have a gene-dosage effect on increasing and decreasing the ET-1 expression in primary OS tumor cells from chemoresistant pediatric OS subjects, respectively.

CONCLUSIONS

This study provides the first evidence of an association between the ET-1 gene SNPs and haplotypes and the risk of chemoresistant pediatric OS, potentially adding new insights into the pathophysiology and treatment of chemoresistant OS.

miR-33a is up-regulated in chemoresistant osteosarcoma and promotes osteosarcoma cell resistance to cisplatin by down-regulating TWIST

BACKGROUND

miRNAs are involved in osteosarcoma (OS) chemoresistance, and TWIST reportedly enhances cisplatin-induced OS cell apoptosis by inhibiting multiple signaling pathways. In this study, we profiled miRNAs differentially expressed in chemoresistant OS, with a focus to identify miRNAs that regulate TWIST expression and OS chemoresistance.

METHODS

OS patients who showed <90% tumor necrosis after neochemotherapy were defined as poor responders (chemoresistant), and those who showed ≥90% tumor necrosis were defined as good responders (control). miRNA microarray analysis was carried out with a discovery cohort (n = 12) of age-, sex- and tumor stage-matched chemoresistant and control OS patients.

RESULTS

Among the up-regulated miRNAs in chemoresistant OS samples, miR-33a was verified to down-regulate TWIST expression, which was supported by an inverse miRNA-33a/TWIST expression trend in the validation cohort (n = 70), target-sequence-specific inhibition of TWIST-3' untranslated region-luciferase reporter activity by miR-33a, and alteration of TWIST expression by overexpression or inhibition of miR-33a in human OS cell lines. In Saos-2 cells treated with cisplatin, inhibition of miR-33a by antagomir-33a markedly increased cell apoptosis, which was enhanced by overexpression of TWIST. The apoptosis-inducing effect of TWIST overexpression was reversed by overexpression of miR-33a. In MG-63 cells, overexpression of miR-33a significantly decreased cisplatin-induced cell apoptosis, which was enhanced by knockdown of TWIST. Antagomir-33a significantly increased cisplatin-induced cell apoptosis, which was reversed by knockdown of TWIST.

CONCLUSIONS

We have demonstrated in this study that miR-33a is up-regulated in chemoresistant OS and that the miR-33a level is negatively correlated with the TWIST protein level in OS. Our in vitro data indicate that miR-33a promotes OS cell resistance to cisplatin by down-regulating TWIST; on the other hand, inhibition of miR-33a by antagomir-33a enhances cisplatin-induced apoptosis in OS cells by up-regulating TWIST expression. The findings suggest that inhibition of miR-33a/TWIST signaling could be a potential new strategy to enhance neoadjuvant chemotherapy for OS.

Association of ITGA3 gene polymorphisms with susceptibility and clinicopathological characteristics of osteosarcoma

Integrin controls cell adhesion to extracellular matrix and plays an important role in regulating the proliferation and apoptosis of cells. In order to explore the role of ITGA3 gene polymorphisms in the pathogenesis and clinicopathological characteristics of osteosarcoma, we embarked on a study including a group of 118 patients and a group of 126 healthy controls. TaqMan PCR genotyping technology was used to detect the genotypes of ITGA3 gene SNPs (rs2230392, rs2285524 and rs16948627) in the peripheral blood. Then, associations of the SNP (rs2230392, rs2285524 and rs16948627) genotypes with the incidence risk and tumor characteristics of osteosarcoma were evaluated. A significant difference (P = 0.02) in the genotype frequency distribution of rs2230392 was observed between case and control groups. The analysis showed that patients carrying AA genotype had a higher risk of osteosarcoma (OR 2.34, 95 % CI 1.18-4.64) than those with GG genotype. Regarding rs2230392, men carrying AA genotype had a higher risk of osteosarcoma (OR 3.37, 95 % CI 1.25-9.11). Compared with those with GG genotype, patients carrying AA genotype had a twofold increased risk of osteosarcoma metastasis (OR 2.46, 95 % CI 1.09-5.57). Survival analysis showed that for rs2230392, survival time of osteosarcoma patients with three different genotypes was significantly different. Polymorphisms of ITGA3 gene rs2230392 may affect the incidence, metastasis and survival of osteosarcoma, which may clinically become a new target for predicting the risk of osteosarcoma, and have prognostic value.

The Current and Future Therapies for Human Osteosarcoma

Osteosarcoma (OS) is the most common non-hematologic malignant tumor of bone in adults and children. As sarcomas are more common in adolescents and young adults than most other forms of cancer, there are a significant number of years of life lost secondary to these malignancies. OS is associated with a poor prognosis secondary to a high grade at presentation, resistance to chemotherapy and a propensity to metastasize to the lungs. Current OS management involves both chemotherapy and surgery. The incorporation of cytotoxic chemotherapy into therapeutic regimens escalated cure rates from <20% to current levels of 65-75%. Furthermore, limb-salvage surgery is now offered to the majority of OS patients. Despite advances in chemotherapy and surgical techniques over the past three decades, there has been stagnation in patient survival outcome improvement, especially in patients with metastatic OS. Thus, there is a critical need to identify novel and directed therapy for OS. Several Phase I trials for sarcoma therapies currently ongoing or recently completed have shown objective responses in OS. Novel drug delivery mechanisms are currently under phase II and III clinical trials. Furthermore, there is an abundance of preclinical research which holds great promise in the development of future OS-directed therapeutics. Our continuously improving knowledge of the molecular and cell-signaling pathways involved in OS will translate into more effective therapies for OS and ultimately improved patient survival. The present review will provide an overview of current therapies, ongoing clinical trials and therapeutic targets under investigation for OS.

Lysyl oxidase polymorphisms and susceptibility to osteosarcoma

Despite the knowledge of many genetic alterations present in osteosarcoma, the complexity of this disease precludes placing its biology into a simple conceptual framework. Lysyl oxidase (LOX) catalyzes the cross-linking of elastin and collagen, which is essential for the structural integrity and function of bone tissue. In the current study, we performed genomic sequencing on all seven exons--including the intron-exon splice sites, and the putative promoter region of LOX gene--followed by luciferase reporter assay to analyze the function of newly identified polymorphisms. Associations between LOX polymorphisms and osteosarcoma were then evaluated. Our sequencing data revealed three polymorphisms (-22G/C, 225C/G, and 473G/A) in the exons and promoter region of LOX. The -22G/C polymorphism lies in the downstream core promoter element (DPE) region and caused a decrease in promoter activity of LOX. The prevalence of the -22C allele and 473A allele were significantly increased in osteosarcoma patients compared to controls (odds ratio [OR] = 3.88, 95% confidence interval [CI]= 1.94-7.78, p = 4.18×10(-5), and OR = 1.38, 95%CI = 1.07-1.78, p = 0.013; p 0.0167 was considered significant after Bonferroni correction). Analyzing haplotype showed that the frequency of CCG haplotype (-22, 225, 473) was significantly higher in osteosarcoma cases than in healthy controls after Bonferroni correction (p = 4.46×10(-4)). These results indicate that the -22G/C polymorphism may affect the expression of LOX, and that -22G/C and 473G/A polymorphisms may be new risk factors for osteosarcoma. These findings reveal a potential new pathway by which genetic polymorphisms may affect human diseases.

Sarcomas as a mise en abyme of mesenchymal stem cells: exploiting interrelationships for cell mediated anticancer therapy

Mise en abyme meaning "placed into abyss or infinite recurrence" is an apt paradigm for the relentless growth of sarcoma cells. Its alternative meaning, "self-reflexive embedding" fits the central role attributed to cancer stem cells (CSCs). Diversely sourced and defined, mesenchymal stem cells (MSCs) may be the cells of sarcoma origin, evolve a CSC phenotype and/or contribute to tumor growth through inherent qualities for homing, neovascularization, paracrine cross-feeding, microvesicle secretion, cell fusion, entosis and immune modulation. Exploiting these qualities, MSC expressing modified forms of the TNF-related apoptosis-inducing ligand (Apo2L/TRAIL) are being developed to complement more conventional radiation and chemotherapy.

New therapeutic targets in soft tissue sarcoma

Soft tissue sarcomas are an uncommon and diverse group of more than 50 mesenchymal malignancies. The pathogenesis of many of these is poorly understood, but others have begun to reveal the secrets of their underlying mechanisms. With considerable effort over recent years, soft tissue sarcomas have increasingly been classified on the basis of underlying molecular alterations. In turn, this has allowed the development and application of targeted agents in several specific, molecularly defined, sarcoma subtypes. This review will focus on the rationale for targeted therapy in sarcoma, with emphasis on the relevance of specific molecular factors and pathways in both translocation-associated sarcomas and in genetically complex tumors. In addition, we will address some of the early successes in sarcoma-targeted therapy as well as a few challenges and disappointments in this field. Finally, we will discuss several possible opportunities represented by poorly understood, but potentially promising new therapeutic targets, as well as several novel biological agents currently in preclinical and early phase I/II trials. This will provide the reader with the context for understanding the current state of this field and a sense of where it may be headed in the coming years.

A short perspective on gene therapy: Clinical experience on gene therapy of gliomablastoma multiforme

More than two decades have passed since the first gene therapy clinical trial was conducted. During this time, we have gained much knowledge regarding gene therapy in general, but also learned to understand the fear that persists in society. We have experienced drawbacks and successes. More than 1700 clinical trials have been conducted where gene therapy is used as a means for therapy. In the very first trial, patients with advanced melanoma were treated with tumor infiltrating lymphocytes genetically modified ex-vivo to express tumor necrosis factor. Around the same time the first gene therapy trial was conducted, the ethical aspects of performing gene therapy on humans was intensively discussed. What are the risks involved with gene therapy? Can we control the technology? What is ethically acceptable and what are the indications gene therapy can be used for? Initially, gene therapy was thought to be implemented mainly for the treatment of monogenetic diseases, such as adenosine deaminase deficiency. However, other therapeutic areas have become of interest and currently cancer is the most studied therapeutic area for gene therapy based medicines. In this review I will be giving a short introduction into gene therapy and will direct the discussion to where we should go from here. Furthermore, I will focus on the use of the Herpes simplex virus-thymidine kinase for gene therapy of malignant gliomas and highlight the efficacy of gene therapy for the treatment of malignant gliomas, but other strategies will also be mentioned.

Biomarkers of breast cancer apoptosis induced by chemotherapy and TRAIL

Treatment of breast cancer is complex and challenging due to the heterogeneity of the disease. To avoid significant toxicity and adverse side-effects of chemotherapy in patients who respond poorly, biomarkers predicting therapeutic response are essential. This study has utilized a proteomic approach integrating 2D-DIGE, LC-MS/MS, and bioinformatics to analyze the proteome of breast cancer (ZR-75-1 and MDA-MB-231) and breast epithelial (MCF-10A) cell lines induced to undergo apoptosis using a combination of doxorubicin and TRAIL administered in sequence (Dox-TRAIL). Apoptosis induction was confirmed using a caspase-3 activity assay. Comparative proteomic analysis between whole cell lysates of Dox-TRAIL and control samples revealed 56 differentially expressed spots (≥2-fold change and p < 0.05) common to at least two cell lines. Of these, 19 proteins were identified yielding 11 unique protein identities: CFL1, EIF5A, HNRNPK, KRT8, KRT18, LMNA, MYH9, NACA, RPLP0, RPLP2, and RAD23B. A subset of the identified proteins was validated by selected reaction monitoring (SRM) and Western blotting. Pathway analysis revealed that the differentially abundant proteins were associated with cell death, cellular organization, integrin-linked kinase signaling, and actin cytoskeleton signaling pathways. The 2D-DIGE analysis has yielded candidate biomarkers of response to treatment in breast cancer cell models. Their clinical utility will depend on validation using patient breast biopsies pre- and post-treatment with anticancer drugs.