Management of undifferentiated embryonal sarcoma of the liver: A Pediatric Surgical Oncology Research Collaborative study

BACKGROUND

Undifferentiated embryonal sarcoma of the liver (UESL) is a rare tumor for which there are few evidence-based guidelines. The aim of this study was to define current management strategies and outcomes for these patients using a multi-institutional dataset curated by the Pediatric Surgical Oncology Research Collaborative.

METHODS

Data were collected retrospectively for patients with UESL treated across 17 children's hospitals in North America from 1989 to 2019. Factors analyzed included patient and tumor characteristics, PRETEXT group, operative details, and neoadjuvant/adjuvant regimens. Event-free and overall survival (EFS, OS) were the primary and secondary outcomes, respectively.

RESULTS

Seventy-eight patients were identified with a median age of 9.9 years [interquartile range [IQR): 7-12]. Twenty-seven patients underwent resection at diagnosis, and 47 patients underwent delayed resection, including eight liver transplants. Neoadjuvant chemotherapy led to a median change in maximum tumor diameter of 1.6 cm [IQR: 0.0-4.4] and greater than 90% tumor necrosis in 79% of the patients undergoing delayed resection. R0 resections were accomplished in 63 patients (81%). Univariate analysis found that metastatic disease impacted OS, and completeness of resection impacted both EFS and OS, while multivariate analysis revealed that R0 resection was associated with decreased expected hazards of experiencing an event [hazard ratio (HR): 0.14, 95% confidence interval (CI): 0.04-0.6]. At a median follow-up of 4 years [IQR: 2-8], the EFS was 70.0% [95% CI: 60%-82%] and OS was 83% [95% CI: 75%-93%].

CONCLUSION

Complete resection is associated with improved survival for patients with UESL. Neoadjuvant chemotherapy causes minimal radiographic response, but significant tumor necrosis.

Biomedical instrumentation of photoacoustic imaging and quantitative sensing for clinical applications

Photoacoustic (PA) imaging has been well researched over the last couple of decades and has found many applications in biomedical engineering. This has evinced interest among many scientists in developing this as a compact instrument for biomedical diagnosis. This review discusses various instrumentation developments for PA experimental setups and their applications in the biomedical diagnostic field. It also covers the PA spectral response or PA sensing technique, which uses the spectral information of the PA signal and performs sensing to deliver a fast, cost-effective, and compact screening tool instead of imaging. Primarily, this review provides an overview of PA imaging concepts and the development of hardware instrumentation systems in both the excitation and acquisition stages of this technique. Later, the paper discusses PA sensing, the quantitative spectral parameter extraction from the PA spectrum, and the correlation study of the spectral parameters with the physical parameters of the tissue. This PA sensing technique was used to diagnose various diseases, such as thyroid nodules, breast cancer, renal disorders, and zoonotic diseases, based on the mechanical and biological characteristics of the tissues. The paper culminates with a discussion section that provides future developments that are necessary to take this technique into clinical applications as a quantitative PA imaging technique.

Abstract 1825: Romidepsin therapy results in p53 mediated apoptosis in hepatoblastoma

Purpose: Relapsed and treatment refractory hepatoblastoma (HB) has a survival rate less than 50% due to limited treatment options. We have previously shown that HB and treatment refractory HB has upregulation of class I histone deacetylase (HDAC) genes (HDAC1-4) through microarray, confirmed by RT-PCR. The highest consistent upregulation noted was with HDAC 2 and 3. Given this upregulation, we tested established and treatment refractory HB cell lines with HDAC 2/3 inhibitor, Romidepsin. We sought to characterize Romidepsin efficacy and mechanism of action.

Methods: Romidepsin was tested with cytotoxic assays (MTT). Tumor derived cell lines were treated with Romidepsin and evaluated for gene expression of p53 pathway via qRT-PCR. Immunoblotting assays were used to assess changes in expression of Acetyl-p53 at time points of 0, 4, 8, and 24 hours after 0.01 µM concentrated Romidepsin treatment. Evaluation of the specific cell death pathway involved was performed via cell viability assays using 0.01 µM concentration of Romidepsin in combination with cell death reversal agents including Z-VAD for apoptosis, 3-Methyladenine for autophagy, Necrostatin-1 for necroptosis, and Ferrostatin-1 for ferroptosis at 48 hours.

Results: Romidepsin (IC50 of 0.001-0.02 µM) showed strong in vitro effects for viability. HB cell lines treated with HDAC inhibitor had increased p21 and PUMA expression on RT-PCR, most notably at the 24-hour mark (p = < 0.05). Acetyl p-53 was noted to increase in HUH-6 and Hep G2 throughout the 24 hours of treatment on western blots, while Hep T1 was noted to have no changes in expression. All cell lines showed the highest level of cell death reversal with ZVAD in cell viability assay after Romidepsin treatment. Hep T1 showed the highest cell death reversal with Romidepsin: relative cell viability of 52% (±5%) versus 95% (±2%) in ZVAD/Romidepsin.

Conclusions: Romidepsin demonstrates strong in vitro efficacy and suggest HDAC 2/3 inhibition may act through p53 mediated mechanism, notably acetylated p53. Cell death via apoptosis is further supported by cell death reversal with ZVAD/Romidepsin treatment in HB cell lines.

Citation Format: Andres F. Espinoza, Richard Whitlock, Rohit Srivastava, Roma Patel, Sai Govindu, Aayushi Shah, Samuel Larson, Sarah Woodfield, Sanjeev Vasudevan. Romidepsin therapy results in p53 mediated apoptosis in hepatoblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1825.

Overcoming resistance to BRAFV600E inhibition in melanoma by deciphering and targeting personalized protein network alterations

BRAFV600E melanoma patients, despite initially responding to the clinically prescribed anti-BRAFV600E therapy, often relapse, and their tumors develop drug resistance. While it is widely accepted that these tumors are originally driven by the BRAFV600E mutation, they often eventually diverge and become supported by various signaling networks. Therefore, patient-specific altered signaling signatures should be deciphered and treated individually. In this study, we design individualized melanoma combination treatments based on personalized network alterations. Using an information-theoretic approach, we compute high-resolution patient-specific altered signaling signatures. These altered signaling signatures each consist of several co-expressed subnetworks, which should all be targeted to optimally inhibit the entire altered signaling flux. Based on these data, we design smart, personalized drug combinations, often consisting of FDA-approved drugs. We validate our approach in vitro and in vivo showing that individualized drug combinations that are rationally based on patient-specific altered signaling signatures are more efficient than the clinically used anti-BRAFV600E or BRAFV600E/MEK targeted therapy. Furthermore, these drug combinations are highly selective, as a drug combination efficient for one BRAFV600E tumor is significantly less efficient for another, and vice versa. The approach presented herein can be broadly applicable to aid clinicians to rationally design patient-specific anti-melanoma drug combinations.

Self-referencing circular dichroism ion yield measurements for improved statistics using femtosecond laser pulses

The combination of circular dichroism with laser mass spectrometry via the measurement of ion yields is a powerful tool in chiral recognition, but the measured anisotropies are generally weak. The method presented in this contribution reduces the measurement error significantly. A common path optical setup generates a pair of counter-rotating laser foci in the interaction region of a time-of-flight spectrometer. As the space focus condition is fulfilled for both foci individually, this becomes a twin-peak ion source with well separated and sufficiently resolved mass peaks. The individual control of polarization allows for in situ correction of experimental fluctuations measuring circular dichroism. Our robust optical setup produces reliable and reproducible results and is applicable for dispersion sensitive femtosecond laser pulses. In this contribution, we use 3-methyl-cyclopentanone as a prototype molecule to illustrate the evaluation procedure and the measurement principle.

Combinatorial effects of trans-cinnamaldehyde with fluoride and chlorhexidine on Streptococcus mutans

AIMS

The aim of this study was to investigate the effects of trans-cinnamaldehyde (TC) and its synergistic activity with chlorhexidine (CHX) and fluoride against Streptococcus mutans.

METHODS AND RESULTS

Streptococcus mutans UA159 was treated with TC alone and in combination with CHX or sodium fluoride. The synergy profile was analysed using the Zero Interaction Potency model. TC showed strong synergism (synergy score of 21·697) with CHX, but additive effect (synergy score of 5·298) with fluoride. TC and the combinations were tested for acid production (glycolytic pH drop) and biofilm formation by S. mutans, and nitric oxide production in macrophages. TC significantly inhibited sucrose-dependent biofilm formation and acid production by S. mutans. Mechanistic studies were carried out by qRT-PCR-based transcriptomic studies which showed that TC acts by impairing genes related to metabolism, quorum sensing, bacteriocin expression, stress tolerance and biofilm formation.

CONCLUSIONS

trans-Cinnamaldehyde potentiates CHX and sodium fluoride in inhibiting S. mutans biofilms and virulence through multiple mechanisms. This study sheds significant new light on the potential to develop TC as an anti-caries treatment.

SIGNIFICANCE AND IMPACT OF THE STUDY

Oral diseases were classified as a 'silent epidemic' in the US Surgeon General's Report on Oral Health. Two decades later, >4 billion people are still affected worldwide by caries, having significant effects on the quality of life. There is an urgent need to develop novel compounds and strategies to combat dental caries. Here, we prove that TC downregulates multiple pathways and potentiates the CHX and fluoride to prevent S. mutans biofilms and virulence. This study sheds significant new light on the potential to develop TC in combination with CHX or fluoride as novel treatments to arrest dental caries.

Nutritional Assessment of Tribal Women in Kainatty, Wayanad: A Cross-Sectional Study

Introduction:

Women from a society reflect the culture that they are a part of and tribal women are the most disadvantaged considering the levels of illiteracy and ignorance. As per the National Family Health Survey 4 reports, in Kerala, undernutrition is particularly common among women from scheduled tribes, 20%. This study was done to assess the nutritional status and its associated factors among tribal women in the reproductive age group at Wayanad.

Materials and Methods:

A hospital-based cross-sectional study was carried out during January 2017 at Amrita Kripa Charitable Hospital in Kainatty, Wayanad. The minimum calculated sample size was 186. Using systematic random sampling, every third tribal woman in the age group of 15–49 years attending the general outpatient department as patient or bystander was interviewed using a pretested semi-structured questionnaire and examined for height, weight, body mass index, and pallor. Data were analyzed using SPSS version 21.

Results:

Data were collected from a total of 223 study participants; 53.8% of them were undernourished (<18.5 kg/m²) with 25% severe underweight and 3.1% and 2.7% preobese and obese women. Participants who were <30 years of age (0.001), those who used smokeless tobacco (0.008), and women from the Paniya tribe 0.001 had significantly higher odds of undernutrition.

Conclusion:

Almost one-fourth of the study participants were severely undernourished and 5.8% belonged to obese and preobese categories, thereby indicating the gravity of the nutritional difficulties among tribal women. A well-planned and coordinated effort is needed to address the scenario of malnutrition among tribal women.

Pediatric gastric adenocarcinoma: A National Cancer Data Base review

PURPOSE

We sought to compare the presentation, management, and outcomes in gastric adenocarcinoma cancer for pediatric and adult patients.

METHODS

Using the 2004 to 2014 National Cancer Database (NCDB), patients ≤21 years (pediatric) were retrospectively compared to >21 years (adult). Chi-squared tests were used to compare categorical variables, and Cox regression was used to estimate hazard ratios (HR) for survival differences.

RESULTS

Of the 129,024 gastric adenocarcinoma cases identified, 129 (0.10%) occurred in pediatric patients. Pediatric cases presented with more advanced disease, including poorly differentiated tumors (81% vs 65%, p = 0.006) and stage 4 disease (56% vs 41%, p = 0.002). Signet ring adenocarcinoma comprised 45% of cases in the pediatric group as compared to 20% of cases in the adults (P < 0.001). Similar proportions in both groups underwent surgery. However, near-total gastrectomy was more common in the pediatric group (16% vs 6%, p < 0.001). The proportions of patients with negative margins, nodal examination, and presence of positive nodes were similar. There was no overall survival difference between the two age groups (HR 0.92, 95% Confidence interval 0.73-1.15).

CONCLUSION

While gastric adenocarcinoma in pediatric patients present with a more advanced stage and poorly differentiated tumors compared to adults, survival appears to be comparable.

TYPE OF STUDY

Retrospective cohort study.

LEVEL OF EVIDENCE

III.

Generation of patient-derived tumor xenografts from percutaneous tumor biopsies in children with bone sarcomas

One of the limitations of performing percutaneous biopsies in patients with bone sarcomas is the small amount of tumor that can be obtained for research purposes. Here, we describe our experience developing patient-derived tumor xenografts (PDXs) using percutaneous tumor biopsies in children with bone sarcomas. We generated 14 bone sarcoma PDXs from percutaneous tumor biopsies. We also developed eight bone sarcoma PDXs from surgical resection of primary bone tumors and pulmonary metastases. A multidisciplinary team approach was critical to establish an accurate diagnosis and to provide adequate tumor samples for PDX generation.

Evolving biopsy techniques for the diagnosis of neuroblastoma in children

BACKGROUND/PURPOSE

To compare the adequacy and safety of percutaneous core needle biopsy and surgical wedge biopsy of neuroblastoma in children.

METHODS

A retrospective review of patients who underwent biopsy for intermediate- or high-risk neuroblastoma at our institution between 2011 and 2015 was performed (recent cohort). Procedure details and outcomes were collected and analyzed using descriptive statistics and Wilcoxon rank tests; P < 0.05 was considered significant. Published data from 2002 to 2010 were compared (historic cohort).

RESULTS

Since 2011, percutaneous, ultrasound-guided, core needle biopsy has been more commonly utilized (47% (16/34) recent vs. 25% (7/28) historic; P = 0.07), and the number of core needle samples increased from median 7 (historic) to 25 (recent). Complications decreased (21% (7/34) recent vs. 64% (18/28) historic; P < 0.01). Biopsy adequacy in the recent cohort was similar (94% percutaneous vs. 89% surgical; P = 1.00), which is improved from the historic cohort (71% percutaneous vs. 100% surgical; P = 0.06). Larger tumors were more likely to have a percutaneous biopsy (82 ± 37 cm percutaneous vs. 47 ± 29 cm surgical; P = 0.04).

CONCLUSIONS

When multiple cores are obtained, percutaneous core needle biopsy is adequate for complete tissue diagnosis of neuroblastoma and can be safely performed. This can be considered as an alternative to open surgical biopsy.

TYPE OF STUDY

Treatment Study.

LEVEL OF EVIDENCE

III.

Abstract B21: Epigenetic modifiers MLL1 and JMJD3 regulate neuroblastoma tumorigenicity by maintaining a cancer stem cell-like population

High-risk neuroblastoma (NB) represents a major clinical challenge in pediatric oncology. Despite significant dose escalation of intense therapies, long-term survival for NB patients remains poor (&lt;45%), and the disease accounts for almost 15% of all pediatric cancer deaths. Relapse of metastatic, drug-resistant disease and treatment-related toxicities mandates the development of new therapeutic strategies. Recently, we discovered a highly tumorigenic, chemoresistant, and self-renewing subpopulation in NB with features similar to cancer stem cells (CSCs). This G-CSF receptor (CD114)-expressing subpopulation can escape initial therapy and cause aggressively invasive relapsed disease. Therefore, developing direct targeting strategies and understanding for the molecular mechanisms maintaining this NB CSC-like subpopulation is essential to delineate effective therapeutics for NB patients. By using siRNA screening approach and low-density pathway arrays, we found that the epigenetic regulators mixed-lineage leukemia-1 (MLL1; KMT2A; a H3K4me3 methyltransferase) and Jumonji D3 (JMJD3; KDM6B; a H3K27me3 demethylase) are important epigenetic regulators for NB proliferation and growth. Interestingly, we found that epigenetic regulators MLL1 and JMJD3 are aberrantly expressed in CD114+ subpopulation and regulate the expression of the G-CSF receptor gene (CSF3R) itself, by maintaining active histone modifications at the promoter locus. Inhibition of MLL1 and JMJD3 with specific small-molecule inhibitors reverses the histone patterns at CSF3R promoter and blocks gene expression, induces apoptosis selectively in CD114+ cells, and inhibits overall NB proliferation in vitro. Furthermore, inhibiting MLL1 and JMJD3 leads to dramatic tumor regression (p&lt;0.001) and reduction in incidences of metastasis (p&lt;0.001) in vivo. Most interestingly, both of these inhibitors increase the overall survival of the treated mice in vivo. As expected, reduction in tumor size was significantly correlated with the reduction in tumor CD114+ cells. Taken together, these data highlight that: a) neuroblastoma is maintained by the complex interplay of epigenetic modifiers, and b) direct targeting of these epigenetic modifiers and combining this approach with current therapy is a novel therapeutic approach to high-risk NB.

Citation Format: Saurabh Agarwal, Julie Tomolonis, Sanjeev Vasudevan, Jason Shohet. Epigenetic modifiers MLL1 and JMJD3 regulate neuroblastoma tumorigenicity by maintaining a cancer stem cell-like population [abstract]. In: Proceedings of the AACR Special Conference: Pediatric Cancer Research: From Basic Science to the Clinic; 2017 Dec 3-6; Atlanta, Georgia. Philadelphia (PA): AACR; Cancer Res 2018;78(19 Suppl):Abstract nr B21.

Partial Nephrectomy for Nephroblastoma: A National Cancer Data Base Review

Standard of care for unilateral nephroblastoma includes total nephrectomy (TN) with nodal sampling. We sought to compare the outcomes of TN and partial nephrectomy (PN). We performed a retrospective cohort study of TN and PN for nephroblastoma using the National Cancer Data Base. The outcomes included nodal sampling frequency, margin status, and survival. Categorical and continuous data were evaluated with χ2 and t tests, respectively ( P < 0.05). Generalized linear models evaluated nodal sampling and margin status. Cox regression compared survival. In total, 235 patients underwent PN and 3572 had TN. TN patients were 50 per cent more likely to undergo nodal sampling (RR: 1.47, 95% CI 1.30–1.66). There was no difference in margin status (RR: 0.91, 95% CI 0.65–1.28) or overall survival (HR 1.57; 95% CI 0.78–3.19). This study reports the largest review of patients with PN for unilateral nephroblastoma. PN patients had less nodal sampling but similar margin involvement and overall survival.

Partial Nephrectomy for Nephroblastoma: A National Cancer Data Base Review

Standard of care for unilateral nephroblastoma includes total nephrectomy (TN) with nodal sampling. We sought to compare the outcomes of TN and partial nephrectomy (PN). We performed a retrospective cohort study of TN and PN for nephroblastoma using the National Cancer Data Base. The outcomes included nodal sampling frequency, margin status, and survival. Categorical and continuous data were evaluated with χ2 and t tests, respectively (P < 0.05). Generalized linear models evaluated nodal sampling and margin status. Cox regression compared survival. In total, 235 patients underwent PN and 3572 had TN. TN patients were 50 per cent more likely to undergo nodal sampling (RR: 1.47, 95% CI 1.30-1.66). There was no difference in margin status (RR: 0.91, 95% CI 0.65-1.28) or overall survival (HR 1.57; 95% CI 0.78-3.19). This study reports the largest review of patients with PN for unilateral nephroblastoma. PN patients had less nodal sampling but similar margin involvement and overall survival.

Abstract 1951: RORα activation opposes MYCN signaling and restores the circadian clock in neuroblastoma

Background. MYCN activation is a hallmark of advanced tumor stage in neuroblastoma (NB), characterizing high-risk patients prone to resistant disease. MYCN is also a potent regulator of metabolic reprogramming that favors NB adaptation to its microenvironment. The retinoic acid receptor-related orphan receptor α (RORα) is a key regulator of cell metabolism, immunity, as well as the circadian rhythm. Importantly, RORα activates the transcriptio of BMAL1, a master circadian transcription factor frequently deregulated in human cancers. Moreover, synthetic ligands RORα agonists (i.e. SR1078) have been recently optimized with great therapeutic potential.

Methods. Multivariate logistic regression analysis identified low levels of RORα as independent predictors of EFS and OS survival in large NB patients’ cohorts (n=890 patients). MYCN inducible over-expression and knock-down NB lines were generated and Q-PCR assays used to assess MYCN-mediated disruption of central components of the clock machinery. Growth-suppressive and pro-apoptotic effects of genetic RORα over-expression and RORα activation (via SR1078) were tested in a panel of MYCN-amplified and non-amplified lines, as well as in MYCN-inducible MYCN-3 cells (Tet-ON). MYCN-amplified xenografts were used to test in vivo therapeutic response to SR1078.

Results. Ectopic MYCN expression upregulates the circadian repressor REV-ERBα and suppresses the circadian activator RORα and the central clock BMAL1. In contrast, MYCN silencing effectively restores their expression levels. Interestingly, the expression of the main regulators of the clock machinery (RORα, REV-ERBα, and BMAL1) are also profoundly altered in MYCN-amplified NB patient samples. Specifically, RORα and BMAL1 are uniformly repressed in MYCN-amplified NB and their reduced levels independently correlate with poor survival in large patients’ cohorts (n=890 patients total, p&lt;0.0001). Importantly, re-activation of RORα (via SR1078) strongly suppresses MYCN transcription and restores BMAL1 levels, inhibiting cell survival. Moreover, SR1078 reduces cell viability and induces apoptotic cell death to a higher extent in MYCN-amplified compared to MYCN-non amplified lines. Lastly, both SR1078 treatment and inducible RORα over-expression significantly (p=0.020) inhibit tumor growth in MYCN NB xenografts. Together, our data suggest that RORα loss promotes MYCN-induced disruption of molecular clock, contributing to NB tumorigenesis. Restoration of RORα opposes these MYCN functions, representing an effective strategy for MYCN-amplified NB.

Citation Format: Myrthala Moreno-Smith, Ling Tao, Ronald Bernardi, Kathleen De Preter, Mario Capasso, Sanjeev Vasudevan, Jason M. Shohet, Eveline Barbieri. RORα activation opposes MYCN signaling and restores the circadian clock in neuroblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1951. doi:10.1158/1538-7445.AM2017-1951

The association between nephroblastoma-specific outcomes and high versus low volume treatment centers

BACKGROUND

Though the volume-outcome relationship has been well-established in adults, low mortality rates and small sample sizes have precluded definitive demonstration in children. This study compares treatment-specific factors for children with nephroblastoma at high (HVC) versus low volume centers (LVC).

METHODS

We performed a retrospective cohort study comparing patients ≤18years with unilateral nephroblastoma treated at HVCs and LVCs using the National Cancer Data Base (1998-2012). Definitions of HVCs included performing above the median, the upper two quartiles, and the highest decile of nephroblastoma resections. Outcomes included nodal sampling, margin status, time to chemotherapy and radiation, and survival. Statistical analyses included χ², t-tests, generalized linear, and Cox regression models (p<0.05).

RESULTS

Of 2911 patients from 210 centers, 1443 (49.6%) were treated at HVCs. There was no difference in frequency of preoperative biopsy or days to radiation (p>0.05). High volume centers were more likely to perform nodal sampling (RR 1.04, 95%CI 1.01-1.08) and had fewer days to chemotherapy (RR 0.80, 95%CI 0.69-0.93). Five-year survival was similar (HVC: 0.93, 95%CI 0.92-0.94; LVC: 0.93, 95%CI 0.91-0.94).

CONCLUSIONS

HVCs were more likely to perform nodal sampling and had fewer days to chemotherapy. There was no difference in days to radiation or survival between centers.

LEVEL OF EVIDENCE

Level II (retrospective prognosis study).

Factors Associated With Mortality in Pediatric vs Adult Nasopharyngeal Carcinoma

IMPORTANCE

Nasopharyngeal carcinoma (NPC) is endemic in some Asian regions but is uncommon in the United States. Little is known about the racial, demographic, and biological characteristics of the disease in pediatric patients.

OBJECTIVES

To improve understanding of the differences between pediatric and adult NPC and to determine whether race conferred a survival difference among pediatric patients with NPC.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included all 17 317 patients with a primary diagnosis of NCP in the National Cancer Data Base from January 1, 1998, to December 31, 2011. Of these, 699 patients were 21 years or younger (pediatric); 16 618 patients, older than 21 years (adult). Data were analyzed after data collection.

EXPOSURE

Pediatric age at diagnosis of NPC.

MAIN OUTCOMES AND MEASURES

Demographic, tumor, and treatment characteristics of pediatric patients with NPC were compared with those of adults using the χ2 test for categorical variables. An adjusted Cox proportional hazards regression model was used to examine survival differences in pediatric patients relative to adult patients. In addition, the risk for pediatric mortality by race was estimated.

RESULTS

Of the 17 317 patients, a total of 699 pediatric and 16 618 adult patients were identified with a primary diagnosis of NPC (female, 239 pediatric patients [34.2%] and 5153 adult patients [32.4%]). Pediatric patients were most commonly black (299 of 686 [43.6%]), whereas adults were most likely to be non-Hispanic white (9839 of 16 504 [60.0%]; P < .001). Pediatric patients were less likely to be Asian (39 of 686 [5.7%]) than were adults (3226 of 16 405 [19.7%]; P < .001). Pediatric patients were more likely to have regional nodal evaluation and to present with stage IV disease (227 of 643 [35.3%] and 330 of 565 [58.4%], respectively) than were adult patients (3748 of 15 631 [24.0%] and 6553 of 13 721 [47.8%], respectively; P < .001 for both comparisons). Pediatric patients had a lower risk for mortality relative to adults (hazard ratio, 0.37; 95% CI, 0.25-0.56). No difference in mortality by racial group was found among pediatric patients (hazard ratio, 1.10; 95% CI, 0.82-1.40).

CONCLUSIONS AND RELEVANCE

Pediatric patients with NPC were more commonly black and presented more frequently with stage IV disease. Pediatric patients had a decreased mortality risk relative to adults, even after adjusting for covariables. Asian race was not associated with increased mortality in pediatric patients with NPC. Racial differences are not associated with an increased risk for mortality among pediatric patients.

Abstract B24: Patient-derived tumor xenograft to study cancer stem cells is pediatric sarcomas

Tumor heterogeneity is recognized as an important hallmark in cancer. This characteristic allows cancer cells to evolve in time, to survive radiation and cyotoxic therapies, and to thrive in different organ microenvironments. Therefore, the presence of distinct tumor subpopulations, as mainstay feature of tumor heterogeneity, may play a role in tumor progression and treatment resistance. Patient-derived xenografts (PDXs) have been used to discover the molecular signaling pathways involved in tumorigenesis, metastasis formation and radiation/chemotherapy resistance in different epithelial-adult cancers. Our research interest in pediatric sarcomas is to understand the processes that drive tumor heterogeneity, to isolate and characterize cancer stem cells (CSCs), and to elucidate the mechanisms of chemoresistance using a PDX model.

Pediatric patients with suspected or established diagnosis of sarcoma evaluated at Texas Children's Hospital signed an informed consent to provide tumor samples for subcutaneous implantation of tumor explants in the flank of nonobese diabetic severe combined immunodeficient gamma (NSG) mice. Tumor explants were implanted on the same day of collection when was possible. First and subsequent PDX generations were harvested for tumor propagation, tumor histology, tumor cell karyotyping , RNA/DNA extraction for genetic studies and fluorescent activated cell sorting (FACS) analysis for ALDH, CD133, EphA2 and CD47.

Forty-six tumor samples have been collected since June 2013. Half of tumor samples (n=21) corresponded to osteosarcoma patients and 59% of all tumor specimens were obtained at the time of the initial biopsy. Approximately 66% of biopsies have been performed by Interventional Radiology in our institution. All PDXs maintained the same histological characteristics that original tumors, and also presented specific genetic translocations associated with the different sarcoma types. Chemotherapy resistant and very aggressive tumors (metastatic) had short tumor latency and generate tumors in all transplanted mice. We did not observe the formation of metastases (lungs or liver) in any of the transplanted PDX mice.

PDXs significantly increased the amount of tumor material necessary to perform cell culture under stem-like cell conditions and to analyze the expression of CSC markers by FACS. These studies would be very difficult to perform directly from patient tumor biopsies. All tumors harvested (n=15) contained 2-9% of ALDH Hi or stem-like cells. None of the PDXs analyzed expressed CD133 but synovial sarcoma. We found that &gt;90% of sarcoma cells expressed CD47 and EphA2 at different intensity levels. Whole genome sequencing of different tumor cell subpopulations and limiting dilution experiments to validate the presence of CSCs are ongoing.

Core needle biopsies would represent the most common source to obtain tumor specimens before treatment in pediatric sarcomas. The development of PDXs allows the propagation of tumor cell subpopulations, including CSCs, without the biological changes impose by cell culture. PDXs resemble the original tumor and constitute a powerful tool to study tumor heterogeneity. We plan to perform orthotopic transplantation and tail vein injection of PDX cells in an attempt to develop a PDX model of metastatic disease in pediatric sarcomas.

Citation Format: Nino Rainusso, Jose Hernandez, Rex Marco, Sanjeev Vasudevan, Norma Quintanilla, John Hicks, Wendy Allen-Rhoades, Matteo Trucco, Jason Yustein. Patient-derived tumor xenograft to study cancer stem cells is pediatric sarcomas. [abstract]. In: Proceedings of the AACR Special Conference: Patient-Derived Cancer Models: Present and Future Applications from Basic Science to the Clinic; Feb 11-14, 2016; New Orleans, LA. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(16_Suppl):Abstract nr B24.

Chronic sensory-motor activity in behaving animals using regenerative multi-electrode interfaces

Regenerative peripheral nerve interfaces have been proposed as viable alternatives for the natural control and feel of robotic prosthetic limbs. We have developed a Regenerative Multi-electrode Interface (REMI) that guides re-growing axons through an electrode array deployed in the lumen of a nerve guide. While acute studies have shown the use of the REMI in the rat sciatic nerve, the quality of chronic signal recording has not been reported. Here we show that implantation of this interface in the sciatic nerve is stable with high quality recordings up to 120 days and failures mainly attributable to abiotic factors related to pedestal detachment and wire breakage. We further tested the interfacing of REMI with fascicles of the sciatic nerve that primarily innervate muscles (tibial) and skin (sural). When implanted into the tibial nerve, bursting activity was observed synchronous to stepping. However, implantation of REMI into the sural nerve failed due to its small size. While fascicles smaller than 300 μm are a challenge for regenerative interfacing, we show that a modified REMI can be used in an insertion mode to record sensory signals from skin. In summary, the REMI represents an effective tool for recording firing patterns of specific axon types during voluntary movement, which may be used to improve the motor control and sensory feedback in closed loop control systems for robotic prosthesis.

Regulation of monocyte induced cell migration by the RNA binding protein, FXR1

FXR1 belongs to a family of RNA-binding proteins that play critical roles in post-transcriptional regulation of gene expression in immunity, development and cancer. FXR1 is associated with regulation of specific mRNAs in myocytes and macrophages. In quiescent cells (> 24 h of extended serum-starvation, ∼30-48 h or more), a spliced isoform of FXR1, FXR1a, promotes translation of the cytokine TNFα, independent of the effects of RNA levels. Here we examined the role of FXR1 in THP1 human monocytic leukemic cells that were grown in serum, as well as in early (24 h) serum-starvation conditions that demonstrates differences in gene expression mechanisms and is distinct from quiescent (> 24 h extended serum-starvation) cells. Global RNA profiling, conducted to investigate the role of FXR1 on mRNA levels, revealed that FXR1 affects levels of specific mRNAs in serum-grown and in early 24 h serum-starvation conditions. FXR1 decreases levels of several mRNAs, including as previously identified, CDKN1A (p21CIP1 or p21) mRNA in serum-grown cells. Interestingly, we find that FXR1 positively regulates mRNA levels of specific cytokines and chemokines in serum-grown and in early 24 h serum-starvation conditions. These include IL1β and CCL2 that control cell migration. Accordingly, depletion and overexpression of FXR1 decreased and increased levels of CCL2 mRNA. Consistent with the reduced levels of IL1β, CCL2 and other chemokines upon FXR1 depletion, our data reveal that depletion of FXR1 decreases the ability of these cells to induce cell migration of neighboring monocytic cells. These data reveal a new role of FXR1 in controlling induction of monocyte migration.

Abstract A15: Epigenetic regulators maintain neuroblastoma cancer stem cells: Model to treatment

High risk neuroblastoma (NB) represents a major clinical challenge in pediatric oncology and accounts for 15% of pediatric cancer deaths. Our recent studies suggest that neuroblastoma tumors are heterogeneous and composed of multiple subpopulations including cancer stem cells (CSCs), marked by Granulocyte Colony Stimulating Factor Receptor (G-CSFR or CD114) positive cells. These CD114+ cells are shown to be highly tumorigenic, metastatic, self-renewing and can differentiate into non-tumorigenic progeny.

As tumor subpopulations typically demonstrate distinct epigenetic modifications at histone H3K4 and H3K27, we evaluate these epigenetic marks at the CSF3R locus (gene encoding G-CSFR) by ChIP-qPCR. Results suggest that the CSF3R gene is switched ‘on’ in NB CSCs via reversible epigenetic histone modifications. The CSF3R promoter in CD114+ NB CSCs, shows increased activating H3K4me3 marks and reduced repressive H3K27me3 marks. In the CD114- bulk tumor population, we found the opposite pattern of increased H3K27me3 marks and reduced H3K4me3 marks. In addition, knockdown of EZH2 (the PRC2 methyltransferase responsible for H3K27me3 marks) increases CD114+ expression in both cell culture and murine xenograft models of neuroblastoma.

Furthermore, gene expression studies revealed high levels of MLL1 (encoded by KMT2A), and Jumonji D3 (JMJD3, encoded by KDM6B) in CD114+ cells. MLL1 is a histone methyltransferase that catalyzes mono-, di- and tri-methylation on H3K4, while JMJD3 is an H3K27me3 demethylase.

Blocking MLL1 and JMJD3 with specific small molecule inhibitors, MM-102 and GSK-J4 reduces overall survival of NB cells and also reduces the percentage of CD114+ cells in vitro. Importantly, targeting these epigenetic regulators rapidly down-regulate the G-CSF receptor expression and induces apoptosis specifically in CD114+ cells but not in CD114- cells, suggesting maintenance of NB CSCs by these epigenetic modifiers. In vivo studies of these epigenetic inhibitors in neuroblastoma murine xenograft models validate our in vitro studies and demonstrate highly significant reduction in overall tumor size and metastasis with correlated reduction of total CD114+ cells in resected tumors.

Overall, we demonstrate that histone modifications play a key role in maintaining the NB cancer stem cells, and that specific epigenetic inhibitors are highly potent anti-tumor agents for high risk neuroblastoma. Our findings have direct translational impact and support the development of epigenetic stem cell targeted therapies for neuroblastoma.

Citation Format: Saurabh Agarwal, Zaowen Chen, Sanjeev Vasudevan, Jason M. Shohet. Epigenetic regulators maintain neuroblastoma cancer stem cells: Model to treatment. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr A15.

Abstract B29: MDM4 is a major p53 regulator in hepatoblastoma

Purpose: Unresectable or metastatic hepatoblastoma generally confers a poor survival. MDM4 and MDM2 are the major negative regulators of p53, which has a predominantly wild type status in hepatoblastoma. Having previously shown that MDM4 has copy gain/amplification associated with the 1q32.1 amplicon in hepatoblastoma, we hypothesize that MDM4 is the predominant negative regulator of p53 function in hepatoblastoma and that blocking MDM4 will cause tumor cell death due to uninhibited p53 tumor suppressor activity.

Methods: An MTT assay was used to measure NSC207895 (MDM4 inhibitor) and Nutlin-3a (MDM2 inhibitor) cytotoxicity on hepatoblastoma cell lines (HepG2, HepT1, and Huh-6) as well as a patient-derived hepatoblastoma cell line (PDCL-1). CCK-8 was used to assess effects of low dose NSC207895 on HB cell line proliferation. Soft agar was used to assess the effect of NSC207895 on hepatoblastoma colony formation. Immunoblotting and quantitative RT-PCR was used to measure expression of p53 downstream targets in hepatoblastoma after treatment with NSC207895. P53 knockdowns were created to assess the effect of NSC207895 in hepatoblastoma in the absence of p53. Cell cycle analysis was performed using BRDU.

Results: Huh-6, HepG2, and HepT1 were all tested with Nutlin-3a and did not show significant cell death (IC50 &gt;10μΜ) inhibition with NSC207895 caused significant cell death in Huh-6 (IC50=1.27μΜ), HepG2 (1.62μΜ), and HepT1 (2.05μΜ). A decrease in cell proliferation was noted with concentrations of NSC207895 as low as 0.05μΜ, 0.1μΜ and 0.3μΜ in HepG2, HepT1, and Huh-6 respectively. An increase in IC50 was seen in the p53 knockdowns compared to each respective control (HepG2: 12.6μΜ vs 3.38μΜ; HepT1: &gt;50μΜ vs 1.45μΜ; Huh-6: 20.2μΜ vs 7.52μΜ). Increased PARP cleavage products and decreased MDM4 expression were seen on immunoblotting after treatment with NSC207895. By both immunoblotting and qPCR, the p53 downstream transcriptional targets, p21, BAX and PUMA, were increased after exposure to NSC207895 in all three cell lines. Cell cycle analysis showed an increased percentage of cells in G1/G0-phase and decreased percentage of actively replicating S-phase cells in HepG2 with NSC207895 treatment.

Conclusion: Our data supports the hypothesis that in hepatoblastoma, MDM4 may be a dominant inhibitor of p53 and inhibition of MDM4 causes p53-mediated cell death and growth inhibition. Therefore, inhibition of MDM4 may be a viable drug target for treating hepatoblastoma.

Citation Format: Yan Shi, Roma Patel, Emporia Hollingsworth, Stephen Sarabia, Jingling Jin, Dolores Lopez-Terrada, Sanjeev Vasudevan. MDM4 is a major p53 regulator in hepatoblastoma. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr B29.

Farnesol quells oxidative stress, reactive gliosis and inflammation during acrylamide-induced neurotoxicity: Behavioral and biochemical evidence

Acrylamide (ACR) is an industrial pollutant, to which humans are exposed through chemicals associated with day to day human life and contributes to neurological disorders. The role of reactive gliosis upon toxic insults remains paradoxical, and the immunomodulatory events during ACR intoxication remain obscure. In view of this, the present study investigated ACR-induced (20mg/kgb.wt for 4weeks) neurodegeneration in the context of oxidative stress and associated inflammatory events and the ability of farnesol, a sesquiterpene, to mitigate reactive gliosis in the brain of Swiss albino mice. Farnesol supplementation (100mg/kgb.wt.) showed a marked improvement in gait performance, neuromuscular function and fine motor coordination and attenuated ACR-induced diminution in glutathione (GSH) with parallel reduction in lipid peroxidation (LPO), protein carbonyls, hydroxide, hydroperoxide and nitrite levels. Farnesol treatment significantly ameliorated ACR-mediated histological aberrations and reactive gliosis by downregulating Glial fibrillary acidic protein (GFAP) and Ionizsed calcium-binding adapter molecule-1 ​(Iba-1) in the cortex, hippocampus and striatum. Further, ACR stimulated increase in levels of pro-inflammatory cytokines such as tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β) and inducible form of nitric oxide synthase (iNOS) were considerably decreased by farnesol. In conclusion, our findings indicate that farnesol exerts neuroprotective efficacy during ACR-induced neuropathology by suppressing reactive gliosis and associated inflammatory events.

Eco-friendly and facilely prepared silica modified amorphous titania (TiO2–SiO2) electrocatalyst for the O2 and H2 evolution reactions

A silica modified amorphous titania (TiO₂–SiO₂) electrocatalyst was prepared by a simple, cheap, and scalable preparation procedure. The catalyst is active in the oxygen and hydrogen evolution reactions, leading to a promising bifunctional electrocatalyst.

Adsorption of herbicide 2-(2,4-dichlorophenoxy)propanoic acid by electrochemically generated aluminum hydroxides: an alternative to chemical dosing

Flow diagram of pilot plant scale studies for the removal of 2,4-DP.

Amplification and over-expression of MAP3K3 gene in human breast cancer promotes formation and survival of breast cancer cells

Gene amplifications in the 17q chromosomal region are observed frequently in breast cancers. An integrative bioinformatics analysis of this region nominated the MAP3K3 gene as a potential therapeutic target in breast cancer. This gene encodes mitogen-activated protein kinase kinase kinase 3 (MAP3K3/MEKK3), which has not yet been reported to be associated with cancer-causing genetic aberrations. We found that MAP3K3 was amplified in approximately 8-20% of breast cancers. Knockdown of MAP3K3 expression significantly inhibited cell proliferation and colony formation in MAP3K3-amplified breast cancer cell lines MCF-7 and MDA-MB-361 but not in MAP3K3 non-amplified breast cancer cells. Knockdown of MAP3K3 expression in MAP3K3-amplified breast cancer cells sensitized breast cancer cells to apoptotic induction by TNFα and TRAIL, as well as doxorubicin, VP-16 and fluorouracil, three commonly used chemotherapeutic drugs for treating breast cancer. In addition, ectopic expression of MAP3K3, in collaboration with Ras, induced colony formation in both primary mouse embryonic fibroblasts and immortalized human breast epithelial cells (MCF-10A). Combined, these results suggest that MAP3K3 contributes to breast carcinogenesis and may endow resistance of breast cancer cells to cytotoxic chemotherapy. Therefore, MAP3K3 may be a valuable therapeutic target in patients with MAP3K3-amplified breast cancers, and blocking MAP3K3 kinase activity with a small molecule inhibitor may sensitize MAP3K3-amplified breast cancer cells to chemotherapy.

Functional validation of microRNA-target RNA interactions

MicroRNAs are small, non-coding RNA regulators of gene expression with important outcomes in cell state, proliferation, metabolism, immunity and development; their deregulation leads to significant clinical consequences. MicroRNAs and their associated target RNAs can be identified by genetic, bioinformatic and biochemical methods. MicroRNAs can recognize target mRNAs via direct base-pairing and recruit effector complexes to modulate their gene expression in a sequence-specific manner. MicroRNA interactions with target RNAs produce their roles in gene expression. The following are some of the validation methods employed to confirm functionally relevant microRNA interactions with their target mRNAs. Each method involves interference with the microRNA or the target mRNA to disable their interaction, which should lead to loss of microRNA-mediated gene expression if the interaction is functionally consequential. Subsequent alleviation of the interference and restoration of productive base-pairing interactions between the microRNA and target should rescue microRNA-mediated gene expression and confirm the functional requirement for direct microRNA-target mRNA interaction. Characterization of functional microRNA interactions with their target mRNAs will provide significant insights into their gene expression regulatory mechanism and lead to the development of potential therapeutic approaches to manipulate these interactions and their consequent gene expression outcomes.

Effect of alternating and direct current in an electrocoagulation process on the removal of cadmium from water

The main objective of this study was to investigate the effects of AC and DC on the removal of cadmium from water using iron as anode and cathode. The various operating parameters on the removal efficiency of cadmium were investigated. The results showed that the optimum removal efficiency of 98.1 and 97.3% with the energy consumption of 0.734 and 1.413 kWh/kL was achieved at a current density of 0.2 A/dm(2), at pH of 7.0 using AC and DC respectively. The adsorption process follows second order kinetics and the temperature studies showed that adsorption was endothermic and spontaneous in nature.

Growth, structural, vibrational, optical, laser and dielectric aspects of L-alanine alaninium nitrate single crystal

Bulk single crystals of l-alanine alaninium nitrate [abbreviated as LAAN], an intriguing material for frequency conversion has been grown from its aqueous solution by both slow solvent evaporation and by slow cooling techniques. The optimized pH value to grow good quality LAAN single crystal was found to be 2.5. The grown crystals were subjected to single crystal X-ray diffraction studies to determine the unit cell dimensions and morphology. Vibrational frequencies of the grown crystals by Fourier transform infrared spectroscopic technique were investigated. Also, the presence of hydrogen and carbon atoms in the grown sample was confirmed using proton and carbon NMR analyses. The dielectric constant and dielectric loss measurements of the as grown crystal at different temperatures and frequencies of the applied field are measured and reported. LAAN has good optical transmission in the entire visible region with cutoff wavelength within the UV region confirms its suitability for device fabrications. The existence of second harmonic generation signals was observed using Nd:YAG laser with fundamental wavelength of 1064 nm. Its Laser Damage Threshold (LDT) was measured and also tested by using a Q-switched Nd:YAG laser and the value of LDT of LAAN is 17.76GW/cm2 respectively, is found to be better than certain organic and semiorganic materials.

Composition driven monolayer to bilayer transformation in a surfactant intercalated Mg-Al layered double hydroxide

The structure and organization of dodecyl sulfate (DDS) surfactant chains intercalated in an Mg-Al layered double hydroxide (LDH), Mg(1-x)Alx(OH)2, with differing Al/Mg ratios has been investigated. The Mg-Al LDHs can be prepared over a range of compositions with x varying from 0.167 to 0.37 and therefore provides a simple system to study how the organization of the alkyl chains of the intercalated DDS anions change with packing density; the Al/Mg ratio or x providing a convenient handle to do so. Powder X-ray diffraction measurements showed that at high packing densities (x ≥ 0.3) the alkyl chains of the intercalated dodecyl sulfate ions are anchored on opposing LDH sheets and arranged as bilayers with an interlayer spacing of ∼27 Å. At lower packing densities (x < 0.2) the surfactant chains form a monolayer with the alkyl chains oriented flat in the galleries with an interlayer spacing of ∼8 Å. For the in between compositions, 0.2 ≤ x < 0.3, the material is biphasic. MD simulations were performed to understand how the anchoring density of the intercalated surfactant chains in the Mg-Al LDH-DDS affects the organization of the chains and the interlayer spacing. The simulations are able to reproduce the composition driven monolayer to bilayer transformation in the arrangement of the intercalated surfactant chains and in addition provide insights into the factors that decide the arrangement of the surfactant chains in the two situations. In the bilayer arrangement, it is the dispersive van der Waals interactions between chains in opposing layers of the anchored bilayer that is responsible for the cohesive energy of the solid whereas at lower packing densities, where a monolayer arrangement is favored, Coulomb interactions between the positively charged Mg-Al LDH sheets and the negatively charged headgroup of the DDS anion dominate.

Application of water quality index for groundwater quality assessment: Thirumanimuttar sub-basin, Tamilnadu, India

An attempt has been made to understand the hydrogeochemical parameters to develop water quality index in Thirumanimuttar sub-basin. A total of 148 groundwater samples were collected and analyzed for major cations and anions. The domination of cations and anions was in the order of Na>Mg>Ca>K for cations and Cl>HCO(3) >SO(4) in anions. The hydrogeochemical facies indicate alkalis (Na and K) exceed alkaline earths (Ca and Mg) and strong acids (Cl and SO(4)) exceed weak acid (HCO(3)). Water quality index rating was calculated to quantify overall water quality for human consumption. The PRM samples exhibit poor quality in greater percentage when compared with POM due to effective leaching of ions, over exploitation of groundwater, direct discharge of effluents and agricultural impact. The overlay of WQI with chloride and EC correspond to the same locations indicating the poor quality of groundwater in the study area. SAR, Na%, and TH were noted higher during both the seasons indicating most of the groundwater locations not suitable for irrigation purposes.