Tumour expressions of hypoxic markers predict the response to neo-adjuvant chemotherapy in children with inoperable rhabdomyosarcoma

The Capacity of Drug-Metabolising Enzymes in Modulating the Therapeutic Efficacy of Drugs to Treat Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a rare soft tissue sarcoma (STS) that predominantly affects children and teenagers. It is the most common STS in children (40%) and accounts for 5-8% of total childhood malignancies. Apart from surgery and radiotherapy in eligible patients, standard chemotherapy is the only therapeutic option clinically available for RMS patients. While survival rates for this childhood cancer have considerably improved over the last few decades for low-risk and intermediate-risk cases, the mortality rate remains exceptionally high in high-risk RMS patients with recurrent and/or metastatic disease. The intensification of chemotherapeutic protocols in advanced-stage RMS has historically induced aggravated toxicity with only very modest therapeutic gain. In this review, we critically analyse what has been achieved so far in RMS therapy and provide insight into how a diverse group of drug-metabolising enzymes (DMEs) possess the capacity to modify the clinical efficacy of chemotherapy. We provide suggestions for new therapeutic strategies that exploit the presence of DMEs for prodrug activation, targeted chemotherapy that does not rely on DMEs, and RMS-molecular-subtype-targeted therapies that have the potential to enter clinical evaluation.

Efficacy and toxicity of carboplatin in the treatment of macroscopic mesenchymal neoplasia in dogs

Palliative chemotherapy options for dogs with macroscopic non-osseous mesenchymal tumours are limited. The purpose of this study was to assess the response rate of these tumours to carboplatin chemotherapy. Medical records of 28 dogs treated with carboplatin for macroscopic mesenchymal neoplasia between 1990 and 2022 were retrospectively reviewed. Sixteen dogs with soft tissue sarcoma and 12 dogs with haemangiosarcoma were included. Responses observed included one complete response and three partial responses, for an overall response rate of 14.2% (4/28) and median time to progression of 42 days (range 21-259 days). Responses were only seen in patients with haemangiosarcoma, for a response rate of 33.3% (4/12) and median time to progression for responders of 103 days (range 39-252 days). Median time to progression for dogs with metastatic disease was similar to those with only local disease (distant median: 44 days; local median: 23 days, p = 0.56). Dogs with chemotherapy-naïve disease were compared to dogs having received previous chemotherapy treatment and had a median time to progression of 75 days and 40.5 days respectively (p = 0.13). Twenty-two dogs experienced 48 adverse events, with most being grade 1 or 2 (79%). Carboplatin was well tolerated, with variable macroscopic anti-tumour activity and short response duration. Carboplatin may be an acceptable rescue option for dogs with macroscopic haemangiosarcoma, especially those patients that cannot receive doxorubicin.

Correlations between DWI, IVIM, and HIF-1α expression based on MRI and pathology in a murine model of rhabdomyosarcoma

PURPOSE

To investigate the correlation between DWI, intravoxel incoherent motion (IVIM), and hypoxia-inducible factor 1-alpha (HIF-1α) expression in a nude mouse model of rhabdomyosarcoma based on imaging and pathological comparisons.

METHODS

Human rhabdomyosarcoma-derived (RD) cells were inoculated into the right thigh muscle of 20 BALB/c female nude mice. Mice were imaged using 3.0 Tesla MRI system. T₁ -weighted imaging, T₂ -weighted imaging, DWI, and IVIM images were obtained. ADW4.7 (GE Healthcare, ChicagoAQ34, IL, USA) was used for image processing of ADC, D_slow , D_fast , and f values. All parameter values were independently analyzed by 2 observers. Immunohistochemistry of HIF-1α was performed. We used a specific image-pathology comparison method to ensure correct overlap between the image plane and the pathological section. Mann-Whitney U test or independent sample t test, Pearson or Spearman correlation test, the intragroup correlation coefficient, Kolmogorov-Smirnov test, and receiver operating characteristic curve were used. The correlation between DWI and intravoxel incoherent motion parameter values and HIF-1α expression was determined.

RESULTS

There were 10 mice in the low-expression group and 7 in the high-expression group. The ADC and D_slow values were negatively correlated with HIF-1α with correlation coefficients of -0.491 and - 0.702 (P = 0.045 and 0.002). The f value positively correlated with HIF-1α expression (r = 0.485, P = 0.048). ADC, D_slow , and f were significantly different between the high-HIF-1α expression tumors and the low-HIF-1α expression tumors. ADC showed the best predictive performance among all parameters (area under the curve = 0.652, sensitivity = 83.3%, specificity = 63.6%).

CONCLUSION

The parameter values of DWI and intravoxel incoherent motion can be used to evaluate the expression of HIF-1α in rhabdomyosarcoma. ADC, D_slow , and f value showed correlation with the expression of HIF-1α.

Splice-switching of the insulin receptor pre-mRNA alleviates tumorigenic hallmarks in rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is an aggressive pediatric tumor with a poor prognosis for metastasis and recurrent disease. Large-scale sequencing endeavors demonstrate that Rhabdomyosarcomas have a dearth of precisely targetable driver mutations. However, IGF-2 signaling is known to be grossly altered in RMS. The insulin receptor (IR) exists in two alternatively spliced isoforms, IR-A and IR-B. The IGF-2 signaling molecule binds both its innate IGF-1 receptor as well as the insulin receptor variant A (IR-A) with high affinity. Mitogenic and proliferative signaling via the canonical IGF-2 pathway is, therefore, augmented by IR-A. This study shows that RMS patients express increased IR-A levels compared to control tissues that predominantly express the IR-B isoform. We also found that Hif-1α is significantly increased in RMS tumors, portraying their hypoxic phenotype. Concordantly, the alternative splicing of IR adapts to produce more IR-A in response to hypoxic stress. Upon examining the pre-mRNA structure of the gene, we identified a potential hypoxia-responsive element, which is also the binding site for the RNA-binding protein CUG-BP1 (CELF1). We designed Splice Switching Oligonucleotides (SSO) against this binding site to decrease IR-A levels in RMS cell lines and, consequently, rescue the IR-B expression levels. SSO treatment resulted in a significant reduction in cell proliferation, migration, and angiogenesis. Our data shows promising insight into how impeding the IGF-2 pathway by reducing IR-A expression mitigates tumor growth. It is evident that Rhabdomyosarcomas use IR alternative splicing as yet another survival strategy that can be exploited as a therapeutic intervention in conjunction with already established anti-IGF-1 receptor therapies.

Introducing Fluorescence-Guided Surgery for Pediatric Ewing, Osteo-, and Rhabdomyosarcomas: A Literature Review

Sarcomas are a rare heterogeneous group of malignant neoplasms of mesenchymal origin which represent approximately 13% of all cancers in pediatric patients. The most prevalent pediatric bone sarcomas are osteosarcoma (OS) and Ewing sarcoma (ES). Rhabdomyosarcoma (RMS) is the most frequently occurring pediatric soft tissue sarcoma. The median age of OS and ES is approximately 17 years, so this disease is also commonly seen in adults while non-pleiomorphic RMS is rare in the adult population. The mainstay of all treatment regimens is multimodal treatment containing chemotherapy, surgical resection, and sometimes (neo)adjuvant radiotherapy. A clear resection margin improves both local control and overall survival and should be the goal during surgery with a curative intent. Real-time intraoperative fluorescence-guided imaging could facilitate complete resections by visualizing tumor tissue during surgery. This review evaluates whether non-targeted and targeted fluorescence-guided surgery (FGS) could be beneficial for pediatric OS, ES, and RMS patients. Necessities for clinical implementation, current literature, and the positive as well as negative aspects of non-targeted FGS using the NIR dye Indocyanine Green (ICG) were evaluated. In addition, we provide an overview of targets that could potentially be used for FGS in OS, ES, and RMS. Then, due to the time- and cost-efficient translational perspective, we elaborate on the use of antibody-based tracers as well as their disadvantages and alternatives. Finally, we conclude with recommendations for the experiments needed before FGS can be implemented for pediatric OS, ES, and RMS patients.

A bioengineering method for modeling alveolar Rhabdomyosarcoma and assessing chemotherapy responses

Rhabdomyosarcoma (RMS) is the most common pediatric soft-tissue malignant tumor. Treatment of RMS usually includes primary tumor resection along with systemic chemotherapy. Two-dimensional (2D) cell culture systems and animal models have been extensively used for investigating the potential efficacy of new RMS treatments. However, RMS cells behave differently in 2D culture than in vivo, which has recently inspired the adoption of three-dimensional (3D) culture environments. In the current paper, we will describe the detailed methodology we have developed for fabricating a 3D engineered model to study alveolar RMS (ARMS) in vitro. This model consists of a thermally cross-linked collagen disk laden with RMS cells that mimics the structural and bio-chemical aspects of the tumor extracellular matrix (ECM). This process is highly reproducible and produces a 3D engineered model that can be used to analyze the cytotoxicity and autophagy induction of drugs on ARMS cells. The most improtant bullet points are as following:•

We fabricated 3D model of ARMS.

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The current ARMS 3D model can be used for screening of chemotherapy drugs.

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We developed methods to detect apoptosis and autophagy in ARMS 3D model to detect the mechansims of chemotherapy agents.

High Expression of Solute Carrier Family 2 Member 1 (SLC2A1) in Cancer Cells Is an Independent Unfavorable Prognostic Factor in Pediatric Malignant Peripheral Nerve Sheath Tumor

Malignant peripheral nerve sheath tumor (MPNST) in children is a rare mesenchymal malignancy developing predominantly in the setting of neurofibromatosis type 1. The prognosis in advanced MPNST is poor therefore new prognostic markers are highly needed for optimal therapeutic decisions. In many solid tumors, the bidirectional interactions between hypoxia and inflammation in the tumor microenvironment via functions of tumor-associated cells, like neutrophils, lymphocytes and macrophages, have been investigated recently. There is no data whether in MPNST hypoxic microenvironment may translate into systemic inflammation, which is a well-established factor for worse prognosis in cancer patients. Therefore, we investigated the prognostic significance of markers of tumor hypoxia and systemic inflammation in 26 pediatric malignant peripheral nerve sheath tumors (MPNST). Tumor tissue microarrays were stained for hypoxia-inducible factor-1α (HIF1A), solute carrier family 2 member 1 (SLC2A1, also known as glucose transporter 1 (GLUT1)), carbonic anhydrase 9 (CA9), and vascular endothelial growth factor A (VEGFA) and classified into low- or high-expression groups. Baseline complete blood counts and C-reactive protein (CRP) levels were collected for all cases. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) were calculated from age-adjusted complete blood count parameters. Both 10-year RFS and OS were significantly lower in patients with high NLR values (17% vs. 75%, p = 0.009, q = 0.018; and 31% vs. 100%, p = 0.0077, q = 0.014; respectively). Ten-year-OS was significantly lower in patients with high expression of SLC2A1 (20.00% vs. 94%, p < 0.001, log-rank), high expression of HIF1A (23% vs. 79%, p = 0.016, log-rank), and CRP higher than 31 mg/L (11% vs. 82%, p = 0.003, q = 0.009). Cox's proportional hazard regression analysis revealed that high expression of SLC2A1 (HR = 3.31, 95% CI = 1.08-10.09, p = 0.036) and VEGFA (HR = 4.40, 95% CI = 0.95-20.34, p = 0.058) were the independent factors predicting relapse, whereas high SLC2A1 was identified as the independent risk factor for death (HR = 12.20, 95% CI = 2.55-58.33, p = 0.002). Patients with high expression of hypoxic markers and low or high NLR/CRP values had the highest events rate, patients with low hypoxic markers and high NLR/CRP had intermediate events rate, while patients with low hypoxic markers and low NLR/CRP had the lowest events rate. SLC2A1 and VEGFA are promising novel prognostic factors in pediatric MPNST. Correlations between hypoxic and systemic inflammatory markers suggest the interplay between local tumor hypoxia and systemic inflammation.

Hypoxia and its therapeutic possibilities in paediatric cancers

In tumours, hypoxia-a condition in which the demand for oxygen is higher than its availability-is well known to be associated with reduced sensitivity to radiotherapy and chemotherapy, and with immunosuppression. The consequences of hypoxia on tumour biology and patient outcomes have therefore led to the investigation of strategies that can alleviate hypoxia in cancer cells, with the aim of sensitising cells to treatments. An alternative therapeutic approach involves the design of prodrugs that are activated by hypoxic cells. Increasing evidence indicates that hypoxia is not just clinically significant in adult cancers but also in paediatric cancers. We evaluate relevant methods to assess the levels and extent of hypoxia in childhood cancers, including novel imaging strategies such as oxygen-enhanced magnetic resonance imaging (MRI). Preclinical and clinical evidence largely supports the use of hypoxia-targeting drugs in children, and we describe the critical need to identify robust predictive biomarkers for the use of such drugs in future paediatric clinical trials. Ultimately, a more personalised approach to treatment that includes targeting hypoxic tumour cells might improve outcomes in subgroups of paediatric cancer patients.

GLUT-1 as a predictor of worse prognosis in pancreatic adenocarcinoma: immunohistochemistry study showing the correlation between expression and survival

BACKGROUND

Various parameters have been considered for predicting survival in pancreatic ductal adenocarcinoma. Information about western population is missing. The aim of this study is to assess the association between Glucose transporter type 1 (GLUT-1) expression and prognosis for patients with PDAC submitted for surgical resection in a European cohort.

METHODS

Retrospective analysis of PDAC specimens after pancreatoduodenectomy assessing GLUT-1 expression according to intensity (weak vs strong) and extension (low if < 80% cells were stained, high if > 80%) was performed. Statistical analysis was performed using the exact Fisher test, Student t test or the Mann-Whitney U test. Survival was analysed using the Kaplan-Meier method and compared with the Log-rank test. The differences were considered significant at a two-sided p value of < 0.05. All statistical analyses were performed using SPSS® 23.0 for Windows (SPSS Inc., Chicago, IL, USA).

RESULTS

Our study consisted of 39 patients of which 58.9% presented with weak and 41.1% with strong intensity. The median extension was 90%: 28.2% cases presented with a low extension and 71.8% with a high extension. No significant differences related to intensity were found. The high-extension group showed a higher percentage of T3 PDAC (92.9% vs 63.6%, p = 0.042) and LNR20 (35.7% vs 0%, p = 0.037) as well as shorter disease-free survival (17.58 vs 54.46 months; p = 0.048).

CONCLUSIONS

Our findings suggest that GLUT-1 could be related to higher aggressivity in PDAC and could be used as a prognostic marker, identifying patients with a worse response to current therapies who could benefit from more aggressive treatments.

Extracellular Chaperones as Novel Biomarkers of Overall Cancer Progression and Efficacy of Anticancer Therapy

Exosomal heat shock proteins (Hsps) are involved in intercellular communication both in physiological and pathological conditions. They play a role in key processes of carcinogenesis including immune system regulation, cell differentiation, vascular homeostasis and metastasis formation. Thus, exosomal Hsps are emerging biomarkers of malignancies and possible therapeutic targets. Adolescents and young adults (AYAs) are patients aged 15–39 years. This age group, placed between pediatric and adult oncology, pose a particular challenge for cancer management. New biomarkers of cancer growth and progression as well as prognostic factors are desperately needed in AYAs. In this review, we attempted to summarize the current knowledge on the role of exosomal Hsps in selected solid tumors characteristic for the AYA population and/or associated with poor prognosis in this age group. These included malignant melanoma, brain tumors, and breast, colorectal, thyroid, hepatocellular, lung and gynecological tract carcinomas. The studies on exosomal Hsps in these tumors are limited; however; some have provided promising results. Although further research is needed, there is potential for future clinical applications of exosomal Hsps in AYA cancers, both as novel biomarkers of disease presence, progression or relapse, or as therapeutic targets or tools for drug delivery.

The Efficacy and Safety of Apatinib in Refractory/Relapse Advanced Pediatric Solid Tumor: A Retrospective Study

Background

The prognosis of recurrent or refractory advanced childhood solid tumor patients is very poor and new therapeutic strategies are in urgent need. This study aimed to determine the efficacy and safety of apatinib in pediatric refractory/relapse advanced solid tumor patients.

Patients and Methods

The study retrospectively reviewed recurrent or refractory advanced pediatric solid tumor patients who were treated with apatinib, an oral small-molecule tyrosine kinase inhibitor (TKI) that targets vascular endothelial growth factor receptor-2 (VEGFR2), at the Sun Yat-sen University Cancer Center (China) from January 2016 to March 2019.

Results

Fifty-six patients were included in the safety evaluation and 49 patients were included in the efficacy evaluation. The objective responses rate (ORR) was 26.5% (95% CI 15–41): 0 CR (complete response) and 13 PR (partial response). Disease control rate (DCR) (CR+PR+SD) was 79.6% (95% CI 65–90). The median progression-free survival (PFS) was 4.0 months (95% CI 2.6–5.4). There was no significant difference for ORR or PFS between the A (apatinib monotherapy), A+MT (apatinib combined with oral metronomic therapy) and A+SC (apatinib combined with salvage combination chemotherapy) group (p>0.05). The most common grade 3 or 4 adverse events were neutropenia (9[16.1%]), thrombocytopenia (8[14.3%]), hand-foot syndrome (3[5.4%]), hypertension (3[5.4%]), anaemia (3[5.4%]) and mucositis (2[3.6%]). Hypertension was the most serious adverse event and one death that occurred was considered as drug-related.

Conclusion

Apatinib showed promising clinical activity in heavily treated recurrent or refractory advanced childhood solid tumor patients. However, it is necessary to pay special attention to monitoring blood pressure when using apatinib in children. Prospective randomized controlled clinical trial is warranted.