Multi-omics analysis of the gut microbiome and metabolites associated with the psychoneurological symptom cluster in children with cancer receiving chemotherapy

BACKGROUND

Children with cancer receiving chemotherapy commonly report a cluster of psychoneurological symptoms (PNS), including pain, fatigue, anxiety, depression, and cognitive dysfunction. The role of the gut microbiome and its functional metabolites in PNS is rarely studied among children with cancer. This study investigated the associations between the gut microbiome-metabolome pathways and PNS in children with cancer across chemotherapy as compared to healthy children.

METHODS

A case-control study was conducted. Cancer cases were recruited from Children's Healthcare of Atlanta and healthy controls were recruited via flyers. Participants reported PNS using the Pediatric Patient-Reported Outcomes Measurement Information System. Data for cases were collected pre-cycle two chemotherapy (T0) and post-chemotherapy (T1), whereas data for healthy controls were collected once. Gut microbiome and its metabolites were measured using fecal specimens. Gut microbiome profiling was performed using 16S rRNA V4 sequencing, and metabolome was performed using an untargeted liquid chromatography-mass spectrometry approach. A multi-omics network integration program analyzed microbiome-metabolome pathways of PNS.

RESULTS

Cases (n = 21) and controls (n = 14) had mean ages of 13.2 and 13.1 years. For cases at T0, PNS were significantly associated with microbial genera (e.g., Ruminococcus, Megasphaera, and Prevotella), which were linked with carnitine shuttle (p = 0.0003), fatty acid metabolism (p = 0.001) and activation (p = 0.001), and tryptophan metabolism (p = 0.008). Megasphaera, clustered with aspartate and asparagine metabolism (p = 0.034), carnitine shuttle (p = 0.002), and tryptophan (p = 0.019), was associated with PNS for cases at T1. Gut bacteria with potential probiotic functions, along with fatty acid metabolism, tryptophan, and carnitine shuttle, were more clustered in cancer cases than the control network and this linkage with PNS needs further studies.

CONCLUSIONS

Using multi-omics approaches, this study indicated specific microbiome-metabolome pathways linked with PNS in children with cancer across chemotherapy. Due to limitations such as antibiotic use in cancer cases, these findings need to be further confirmed in a larger cohort.

Abstract 6731: Gut microbiome associated with the psychoneurological symptom cluster among children with solid tumors receiving chemotherapy

Background: Children with cancer (CWC) receiving chemotherapy (chemo) report significant suffering from a cluster of psychoneurological symptoms (PNS), including pain, fatigue, anxiety, depression, and cognitive dysfunction. Continuous or severe PNS reduce a child’s quality of life. Chemo can disturb the gut microbiome (GM), which is associated with PNS based on the gut-brain axis. This study aimed to examine associations of GM with PNS and the PNS cluster in CWC undergoing chemo.

Methods: An observational prospective study was conducted in 21 CWC enrolled from Children’s Healthcare of Atlanta. Children with at least 1 cycle of chemo were consented pre-cycle 2 chemo (T1) and followed at the end of chemo (T2). At T1, parents reported children’s demographics; at T1 and T2, PNS (pain, fatigue, anxiety, depression, cognitive dysfunction) were reported by children by the Pediatric PROMIS scales and fecal specimens were collected for GM. T-score of the PROMIS scales was computed; an average of T-scores of the five PNS was computed for the PNS cluster. T-score >50 indicates a significant symptom or symptom cluster. 16S rRNA V4 gene from fecal specimens was sequenced for GM. QIIME 2 was used to examine associations of α- and β-diversity with PNS. Linear discriminant analysis effect size identified microbial taxa associated with each PNS and the PNS cluster.

Results: We analyzed 21 CWC with a mean age of 13 years, 67% male, and 67% white. Children at T2 had higher fatigue (54% vs. 43%), cognitive dysfunction (69% vs. 43%), depressive symptoms (23% vs. 19%), and multiple PNS (62% vs. 48%), but lower pain interference (31% vs. 38%) and anxiety (23% vs. 38%) than those at T1. No association was found for α-diversity at T1; higher α-diversity was associated with lower cognitive dysfunction (Faith’s phylogenetic diversity, p=0.04) and anxiety (Pielou’s_e, p=0.08) at T2; β-diversity (Jaccard distance) showed the GM dissimilarities by levels of pain interference (moderate vs. severe, p=0.02) and levels of anxiety (mild vs. moderate, p=0.07). After controlling for study timepoint, children with low pain interference had an enriched Bacteroides; those with low fatigue had enriched Bacteroides and Turicibacter; those with normal cognitive function had enriched Parasutterella, UBA1819, NK4A214, Sellimonas, and Ruminococcaceae. Children without the PNS cluster had enriched Bacteroides, while those with the PNS cluster had enriched Enterobacteriaceae. Children without multiple PNS had enriched UCG_003.

Conclusions: Children with low PNS showed a higher α-diversity and a higher abundance of taxa involved in nutrition and vitamin metabolism (eg, Bacteroides), reducing inflammation (eg, Turicibacter), and producing short chain fatty acids (eg, Ruminococcaceae). These findings provide potential solutions to treat PNS. Further work is needed to corroborate these associations in CWC.

Citation Format: Jinbing Bai, Melissa Martin, Kathryn S. Sutton, Christie Powell, Thomas Olson, Hye In Noh, Maria C. Swartz, Deborah Watkins Bruner. Gut microbiome associated with the psychoneurological symptom cluster among children with solid tumors receiving chemotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6731.

The tumor microenvironment and immune targeting therapy in pediatric renal tumors

This review highlights the role of several immunomodulating elements contributing to the tumor microenvironment of various pediatric renal tumors including Wilms tumor. The roles of innate and adaptive immune cells in renal tumors are summarized as well as immunomodulatory cytokines and other proteins. The expression and the predictive role of checkpoint modulators like PD-L1 and immunomodulating proteins like glypican-3, B7-H3, COX-2 are highlighted with a translational view toward potential therapeutic innovations. We further discuss the current state of preclinical models in advancing this field of study. Finally, examples of clinical trials of immunomodulating strategies such as monoclonal antibodies and chimeric antigen receptor T (CAR-T) cells for relapsed/refractory/progressive pediatric renal tumors are described.

Abstract 720: Comparison of the gut microbiome between children with solid tumor receiving chemotherapy and healthy children

Background: Chemotherapy is commonly used for children with cancer. Intensive chemotherapy can disturb the gut microbiome, which may be associated with treatment-related toxicities. This study aimed to compare profiles of the gut microbiome in children with solid tumors pre- and post-chemotherapy with those of healthy children.

Methods: A case-control study was conducted in 44 children (21 with solid tumors and 23 healthy). Children aged 7-18 years with solid tumors receiving chemotherapy were recruited from Children’s Healthcare of Atlanta (CHOA); healthy children were recruited by e-news in CHOA. The gut microbiome was measured using stool specimens that were collected pre cycle 2 chemotherapy and post the completion of all chemotherapy for cancers, and only once for healthy controls. Demographics and clinical variables (e.g., race and use of antibiotics) were reported by parents. Bacterial 16S rRNA gene V4 region was amplified and sequenced. Bacterial taxonomies were assigned using the Silva reference via QIIME 2. Permutational multivariate analysis of variance, analysis of composition of microbiomes, and linear discriminant analysis effect size were used to compare the gut microbiome between cancer and healthy children.

Results: Children with solid tumors and healthy controls showed no differences in age, race, and BMI; more boys were enrolled in the solid tumor group than the healthy group (p=0.009). Both groups were dominated by phyla Firmicutes and Bacteroidetes. Compared to healthy children, children with solid tumors had significantly lower α-diversity metrics: Shannon p=0.042 and Chao1 p=0.015; children pre- (Shannon p=0.021; Chao1 p=0.024) and post-chemotherapy (Shannon p=0.011; Chao1 p=0.025) showed lower α-diversity metrics than healthy children; and difference was not significant between children pre- and post-chemotherapy. The β-diversity analysis (Bray-Curtis distance) showed that study group (p=0.008), gender (p=0.017), race (p=0.009), and cancer type (p=0.001) impacted the gut microbiome dissimilarities. Children with solid tumors had a lower abundance of phylum Verrucomicrobiotaand a higher abundance of genus Acidaminoccous than healthy controls; healthy children had a higher abundance of beneficial genera Prevotella and Akkermansia. Children with solid tumors had enriched in pathogenic oropportunistically pathogenic genera Clostridioides and Enterococcus. Children post all chemotherapy had enriched genera Blautia and CAG-352 associated with gut-brain axis.

Conclusions: Children with solid tumors suggested different diversity profiles of the gut microbiome and a higher abundance of pathogenic taxa than healthy children. These different gut microbial profiles may be associated with treatment toxicities. Additional studies are needed to further corroborate these associations in children with cancer and reveal the underlying mechanisms.

Citation Format: Jinbing Bai, Kumru Kocaman, Julia Slack, Melissa Martin, Christie Powell, Kathryn S. Sutton, Bradley George, Thomas Olson, Konstantinos T. Konstantinidis, Deborah W. Bruner. Comparison of the gut microbiome between children with solid tumor receiving chemotherapy and healthy children [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 720.

How to Maintain a Healthy Gut Microbiome in Children with Cancer? Gut Microbiome Association with Diet in Children with Solid Tumors Postchemotherapy

Malnutrition is a common complication in children with cancer. Cancer treatment and malnutrition can disrupt gut microbiome diversity and composition. The gut microbiome is of broad interest to better understand the mechanisms of malnutrition in cancer therapy. This study aimed to compare the gut microbiome between children with solid tumors postchemotherapy and healthy controls, and investigated the association of the putative microbiome differences with diet. Study participants were 27 children (7-18 years) with solid tumors within the first year after the completion of chemotherapy and 22 healthy controls. The study groups did not have a statistically significant difference in age, race, sex, and body mass index. At study intake, the participants completed the Block Kids Food Screener for dietary intakes in the past week. Fecal specimens were collected and analyzed for the gut microbiome. The cancer and control groups differed in gut microbial β-diversity and abundance analyses. The macronutrient intakes such as carbohydrates, fiber, beta-carotene, and vitamin B6 were positively associated with α-diversity. Children with adequate vitamin B6 had a higher Chao1 diversity index than children with inadequate or excessive intake (p = 0.0004). Children with excessive selenium intake had a trend for higher Pielou's_e index than children with inadequate intake (p = 0.091). Maintaining a healthy gut microbiome is critical among children with cancer. This study provides new insights on the linkages between dietary intakes and the gut microbiome in children with solid tumors postchemotherapy. These findings, if replicated in future independent studies, may help anticipate malnutrition and plan for personalized nutrition approaches during chemotherapy in pediatric cancers.

Head and Neck Langerhans Cell Histiocytosis in Children

PURPOSE

Controversy exists among head and neck surgical specialties regarding management of Langerhan's Cell Histiocytosis (LCH). The purpose of this study was to evaluate diagnosis, management, and treatment outcomes in children with LCH of the head and neck.

METHODS

This is a retrospective cohort study of children with LCH of the head and neck who presented to Children's Healthcare of Atlanta hospital from 2009 to 2021. The independent variables were demographic information, lesion locations, clinical presentation, radiographic findings, diagnostic workup, treatment, and length of follow-up. The patients were grouped based on these variables. The outcome variable was disease reactivation. Descriptive statistics were calculated.

RESULTS

There were 3 presentations of LCH of the head and neck. Group 1 presented as a lesion in 1 system without CNS risk (SS-). There were 24 patients with an average age of 10 years. Lesions were located in calvaria and/or mandible. Majority of the patients were treated with only debridement. Two of the patients experienced reactivation. Group 2 presented as a lesion in 1 system with CNS risk (SS+). There were 30 patients with an average age of 6 years. Common locations were temporal bone and/or orbit. These patients present with recurrent ear infections and ptosis. Majority of the patients were treated with chemotherapy (n = 28). One patient had disease reactivation. Group 3 presented with multisystem involvement. There were 13 patients with an average age of 2 years. LCH was found in skin and the lymphatic system. Imaging demonstrated extracranial organ involvement. All of them were treated with chemotherapy. There was 40% reactivation of LCH.

CONCLUSIONS

Treatment of LCH depends on presentation. SS- subgroup can be adequately treated via surgical debridement. SS+ and multisystem groups benefit from an early disease diagnosis and require chemotherapy.

Progress Update in Pediatric Renal Tumors

PURPOSE OF REVIEW

Pediatric renal tumors account for 7% of new cancer diagnoses in children. Here, we will review results from recently completed clinical trials informing the current standard of care and discuss targeted and immune therapies being explored for the treatment of high risk or relapsed/refractory pediatric renal malignancies.

RECENT FINDINGS

Cooperative group trials have continued to make improvements in the care of children with pediatric tumors. In particular, trials that standardize treatment of rare cancers (e.g., bilateral Wilms tumor) have improved outcomes significantly. We have seen improvements in event free and overall survival in recently completed clinical trials for many pediatric renal tumors. Still, there are subsets of rarer cancers where outcomes remain poor and new therapeutic strategies are needed. Future trials aim to balance treatment toxicity with treatment efficacy for those with excellent outcomes while identifying novel therapeutics for those with poor outcomes.

Ex vivo expanded patient-derived γδ T-cell immunotherapy enhances neuroblastoma tumor regression in a murine model

An effective therapy regimen for relapsed/refractory high-risk neuroblastoma (NB) includes the anti-GD2 monoclonal antibody, dinutuximab, in combination with temozolomide and irinotecan, supporting a role for chemo-immunotherapy in NB. γδ T cells are an attractive anti-tumor immunotherapy because of their direct cytotoxic activity mediated through cell surface receptors NKG2D and CD16. NKG2D facilitates the innate recognition of stress-induced ligands whereas CD16 recognizes antibody bound to tumors and activates mechanisms of antibody-dependent cellular cytotoxicity (ADCC). This study demonstrates an efficient method for expanding and storing γδ T cells from NB patient-derived apheresis products at clinically relevant amounts. The expanded patient-derived γδ T cells were cytotoxic against the K562 cell line and multiple NB cell lines. Combining γδ T cells with dinutuximab led to a 30% increase in tumor cell lysis compared to γδ T cells alone. Furthermore, low-dose temozolomide in combination with expanded γδ T cells and dinutuximab resulted in increased IFNγ secretion and increased γδ T-cell surface expression of FasL and CD107a. IMR5 NB cell line xenografts established subcutaneously in NSG mice were treated with a regimen of dinutuximab, temozolomide, and γδ T cells. This combination caused targeted killing of NB xenografts in vivo, reducing tumor burden and prolonging survival. These data support the continued preclinical testing of dinutuximab and temozolomide in conjunction with γδ T-cell immunotherapy for patients with recurrent/refractory NB.

Abstract B42: The properties of ex vivo expanded γδ T cells provide for the rational use of combination therapies

Cell-based immunotherapies have relied mainly on the use of αβ T cells or dendritic cells, and technologies to expand and engineer these cells have resulted in potent antitumor products. Although the use of adaptive immunocompetent cells has advanced more rapidly than innate immune cells, such as natural killer or γδ T cells, these alternative cellular products can provide equivalent antitumor activity. However, the methods to expand clinically relevant innate cell products are not as advanced as those for other immunocompetent cells, such as αβ T cells. We have developed a safe and efficient method for expanding, storing, and genetically engineering γδ T cells, and have focused on the use of these ex vivo expanded cells to treat pediatric neuroblastoma. γδ T cells are an attractive candidate for cell-based products because their antitumor activity is directly cytolytic to tumor cells, in part, due to their receptors NKG2D and CD16. NKG2D facilitates the innate recognition of stress-induced ligands such as MICA/B and UL-16 binding proteins (ULBP), and CD16 enables mechanisms of antibody-dependent cellular cytotoxicity (ADCC). We have developed a serum-free expansion protocol using apheresis products from healthy donors and from neuroblastoma patients. γδ T cells from all starting products can be expanded to greater than 70% of the culture within 12-14 days. These γδ T cells are cytotoxic against K562 cells, which has become our standard for which to compare the various expansion products, and 5 human derived neuroblastoma cell lines. We have tested several freezing media and developed a method using serum-free conditions between days 12-14 of expansion, resulting in equivalent cytotoxicity by cells pre- and post-freezing while maintaining greater than 70% viability post-thaw. We also show that our expansion protocol results in γδ T cells that are greater than 90% positive for surface expression of the receptors NKG2D and CD16. Therefore, we are using these cells in combination treatments that include standard chemotherapy regimens for relapsed neuroblastoma patients, i.e., temozolomide (TMZ), and the monoclonal antibody dinutuximab. We have shown that stress antigens such as MICA/B and ULBP2/5/6 are upregulated in vitro on IMR5 cells for 6 hours after a 1-hour exposure to TMZ. Further, combining patient-expanded γδ T cells that express CD16 with a GD2-specific antibody, dinutuximab, induces 30% increased neuroblastoma cell death compared to γδ T cells alone. To test the in vivo effectiveness of 12-day expanded, frozen, and thawed cells, we injected NSG male and female mice with 5 x 106 IMR5 cells subcutaneously. After a palpable 125-mm3 tumor was established, we began treatment with various combinations of γδ T cells, dinutuximab, and TMZ. These ongoing studies show that γδ T cells alone do not provide an antitumor benefit, but tumor regression is achieved when incorporating γδ T cells into dinutuximab and TMZ treatment regimens. This advantage is only observed at lower TMZ doses, whereas at higher TMZ doses, >60 mg/kg, chemotherapy dominates the antitumor effect. Overall, these studies show that a safer, serum-free expanded γδ T cell product can be produced, which can be stored frozen without affecting the cytotoxic properties. The expression of NKG2D and CD16 on the expanded cells allows for the development of combination therapies using cytotoxic chemotherapy agents and antibody-based treatments. The combination of γδ T cells, TMZ, and dinutuximab can provide a rational advancement for treating pediatric neuroblastoma patients, and we hypothesize that this combination therapy is preferred over high-dose chemotherapy regimens because it can reduce treatment-related toxicities and provide a multifaceted immunotherapeutic approach to neuroblastoma treatment.

Citation Format: Jaquelyn T. Zoine, Kathryn S. Sutton, Kristopher A. Knight, Kelly C. Goldsmith, Christopher B. Doering, H. Trent Spencer. The properties of ex vivo expanded γδ T cells provide for the rational use of combination therapies [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 B42.

Bioengineering and serum free expansion of blood-derived γδ T cells

BACKGROUND AIMS

Cellular immunotherapy relies on several highly variable patient-specific parameters, such as (i) cell number before and after expansion, (ii) targeting of cells to tumors, (iii) cell survival and function after infusion, and (iv) on- and off-target adverse events. Cellular approaches such as the specific expansion of γδ T cells as opposed to αβ T cells are being pursued. γδ T cells are reasonable candidates for immunotherapy because they (i) possess intrinsic anti-tumorigenicity, (ii) require no priming, (iii) direct tumor killing via recognition of stress-responsive ligands, and (iv), as we now show, can be expanded to clinical cell doses in current Good Manufacturing Practice serum-free media (SFM).

METHODS

γδ T-cell expansion was evaluated in several SFMs. Additionally, the expanded γδ T cells were evaluated for their transduction efficiency using lentiviral vectors (LV).

RESULTS

Of the SFM cultures, robust expansion was only observed in OpTmizer supplemented with high-dose interleukin-2. γδ T-cell percentages and numbers were sufficient for clinical use. Using cells from several donors, transduction efficiencies ranged from 13 to 33%, which is similar to transduction levels observed using αβ T cells with similar multiplicity of infection.

DISCUSSION

An optimized method of γδT-cell expansion and transduction was developed that can be tested in early-phase clinical trials. With appropriate elimination of the αβT cell-component, the absence of MHC-restriction affords the opportunity for use in the allogeneic setting with limited risk of graft versus host disease. Finally, the use of SFM provides clinically safer, widely applicable and potentially more efficacious cellular immunotherapy.

Immune markers of disease severity and treatment response in pediatric acquired aplastic anemia

BACKGROUND

To investigate the immune status among pediatric patients with aplastic anemia (AA) and explore PNH-status, T-regulatory and NK-cell frequency as potential markers of clinical response.

METHODS

Data were retrospectively analyzed from twenty-six patients diagnosed with AA. PNH populations, T- and NK-subsets were determined via flow cytometry.

RESULTS

At diagnosis, 9/23 patients with severe AA (SAA) versus 1/3 with moderate AA (MAA) were PNH(pos) . Among PNH(pos) patients treated with ATG based immunosuppression, 2/6 had a complete response (CR), while 4/6 had a partial response (PR), similarly 2/6 PNH(neg) patients had a CR and 4/6 had a PR. Lymphocyte subset immunophenotyping revealed that T-regulatory cells represented 7.2% of total lymphocytes at diagnosis. Their frequency varied with disease severity (5.5% for SAA and 14.1% for MAA) and response (8.9% for CR and 1.5% for PR), generally increasing following therapy with IST (14.6%). The NK cell frequency was not substantially different based on disease severity or response.

CONCLUSIONS

Neither PNH cell populations, nor NK cell frequency corresponded with disease severity or response. T-regulatory cell frequency, although not statistically significant given the small sample size, corresponded with both severity and response, indicating potential utility as a prognostic tool.

Cellular and molecular action of the putative GABA-mimetic, gabapentin

Gabapentin was originally designed as an anti-convulsant gamma-aminobutyric acid (GABA) mimetic capable of crossing the blood-brain barrier. In the present review we show that although gabapentin is not a GABA mimetic, it has great utility as an add-on therapy for epilepsy and as a first-line treatment for neuropathic pain. We summarise the studies that have been performed which demonstrate that gabapentin appears to interact with a novel binding site expressed at high density within the central nervous system (CNS), namely the alpha2delta voltage-dependent calcium channel subunit. The review continues by examining the effects of gabapentin on calcium channel function and neurotransmitter release before, in the latter part of the review, summarising the more recently discovered actions of gabapentin in relation to intracellular signalling.