High-Dose Chemotherapy with Autologous Hematopoietic Stem-Cell Rescue for Pediatric Brain Tumor Patients: A Single Institution Experience from UCLA

Background. Dose-dependent response makes certain pediatric brain tumors appropriate targets for high-dose chemotherapy with autologous hematopoietic stem-cell rescue (HDCT-AHSCR). Methods. The clinical outcomes and toxicities were analyzed retrospectively for 18 consecutive patients ≤19 y/o treated with HDCT-AHSCR at UCLA (1999–2009). Results. Patients' median age was 2.3 years. Fourteen had primary and 4 recurrent tumors: 12 neural/embryonal (7 medulloblastomas, 4 primitive neuroectodermal tumors, and a pineoblastoma), 3 glial/mixed, and 3 germ cell tumors. Eight patients had initial gross-total and seven subtotal resections. HDCT mostly consisted of carboplatin and/or thiotepa ± etoposide (n = 16). Nine patients underwent a single AHSCR and nine ≥3 tandems. Three-year progression-free and overall survival probabilities were 60.5% ± 16 and 69.3% ± 11.5. Ten patients with pre-AHSCR complete remissions were alive/disease-free, whereas 5 of 8 with measurable disease were deceased (median followup: 2.3 yrs). Nine of 13 survivors avoided radiation. Single AHSCR regimens had greater toxicity than ≥3 AHSCR (P < .01). Conclusion. HDCT-AHSCR has a definitive, though limited role for selected pediatric brain tumors with poor prognosis and pretransplant complete/partial remissions

Publisher Correction to: Anti-GD2 immunoliposomes loaded with oxamate for neuroblastoma (Pediatric Research, (2023), 10.1038/s41390-023-02479-4)

Due to a publisher’s error, the uncorrected proof PDF of this article was unfortunately published by mistake and has now been replaced by the correct version. The original article has been corrected

In search of druggable targets for GBM amino acid metabolism

Background: Amino acid (AA) pathways may contain druggable targets for glioblastoma (GBM). Literature reviews and GBM database (http://r2.amc.nl) analyses were carried out to screen for such targets among 95 AA related enzymes. Methods: First, we identified the genes that were differentially expressed in GBMs (3 datasets) compared to non-GBM brain tissues (5 datasets), or were associated with survival differences. Further, protein expression for these enzymes was also analyzed in high grade gliomas (HGGs) (proteinatlas.org). Finally, AA enzyme and gene expression were compared among the 4 TCGA (The Cancer Genome Atlas) subtypes of GBMs. Results: We detected differences in enzymes involved in glutamate and urea cycle metabolism in GBM. For example, expression levels of BCAT1 (branched chain amino acid transferase 1) and ASL (argininosuccinate lyase) were high, but ASS1 (argininosuccinate synthase 1) was low in GBM. Proneural and neural TCGA subtypes had low expression of all three. High expression of all three correlated with worse outcome. ASL and ASS1 protein levels were mostly undetected in high grade gliomas, whereas BCAT1 was high. GSS (glutathione synthetase) was not differentially expressed, but higher levels were linked to poor progression free survival. ASPA (aspartoacylase) and GOT1 (glutamic-oxaloacetic transaminase 1) had lower expression in GBM (associated with poor outcomes). All three GABA related genes glutamate decarboxylase 1 (GAD1) and 2 (GAD2) and 4 aminobutyrate aminotransferase (ABAT) - were lower in mesenchymal tumors, which in contrast showed higher IDO1 (indoleamine 2, 3-dioxygenase 1) and TDO2 (tryptophan 2, 3-diaxygenase). Expression of PRODH (proline dehydrogenase), a putative tumor suppressor, was lower in GBM. Higher levels predicted poor survival. Conclusions: Several AA-metabolizing enzymes that are higher in GBM, are also linked to poor outcome (such as BCAT1), which makes them potential targets for therapeutic inhibition. Moreover, existing drugs that deplete asparagine and arginine may be effective against brain tumors, and should be studied in conjunction with chemotherapy. Last, AA metabolism is heterogeneous in TCGA subtypes of GBM (as well as medulloblastomas and other pediatric tumors), which may translate to variable responses to AA targeted therapie

The humanin analogue (HNG) prevents temozolomide-induced male germ cell apoptosis and other adverse effects in severe combined immuno-deficiency (SCID) mice bearing human medulloblastoma

Subfertility is a major concern of long-term cancer survivors at the reproductive age. We have previously demonstrated that a potent humanin analogue, HNG, protected chemotherapy-induced apoptosis in germ cells but not cancer cells in a metastatic melanoma allograft model. In this study, we utilized severe combined immuno-deficiency (SCID) mice bearing human medulloblastoma to study the effect of HNG in Temozolomide (TMZ) induced male germ cell apoptosis and white blood cell (WBC) suppression. Human medulloblastoma DAOY cells were injected subcutaneously into the right flank of male SCID mice. Three weeks later, groups of tumor-bearing mice received one of the following treatments: vehicle, HNG, TMZ, or TMZ + HNG. 24 h after last injection, the tumors weights, complete blood counts, liver and spleen weights, male germ cell apoptosis was assessed. HNG did not affect TMZ's significant anti-tumor action. HNG significantly prevented TMZ-induced germ cell apoptosis and attenuated the suppressed total WBC and granulocyte counts in SCID mice with or without TMZ treatment. HNG also attenuated TMZ-induced body weight loss and decrease of spleen and liver weights. In conclusion, HNG ameliorated TMZ-induced germ cell apoptosis; WBC and granulocytes loss; and decreased body/organ weights without compromising the TMZ's anti-cancer action on medulloblastoma xenografts in SCID mice

Clinical aggressiveness of malignant gliomas is linked to augmented metabolism of amino acids.

Glutamine, glutamate, asparagine, and aspartate are involved in an enzyme-network that controls nitrogen metabolism. Branched-chain-amino-acid aminotransferase-1 (BCAT1) promotes proliferation of gliomas with wild-type IDH1 and is closely connected to the network. We hypothesized that metabolism of asparagine, glutamine, and branched-chain-amino-acids is associated with progression of malignant gliomas. Gene expression for asparagine synthetase (ASNS), glutaminase (GLS), and BCAT1 were analyzed in 164 gliomas from 156 patients [33-anaplastic gliomas (AG) and 131-glioblastomas (GBM), 64 of which were recurrent GBMs]. ASNS and GLS were twofold higher in GBMs versus AGs. BCAT1 was also higher in GBMs. ASNS expression was twofold higher in recurrent versus new GBMs. Five patients had serial samples: 4-showed higher ASNS and 3-higher GLS at recurrence. We analyzed grade and treatment in 4 groups: (1) low ASNS, GLS, and BCAT1 (n&nbsp;=&nbsp;96); (2) low ASNS and GLS, but high BCAT1 (n&nbsp;=&nbsp;26); (3) high ASNS or GLS, but low BCAT1 (n&nbsp;=&nbsp;25); and (4) high ASNS or GLS and high BCAT1 (n&nbsp;=&nbsp;17). Ninety-one &nbsp;% of patients (29/32) with grade-III lesions were in group 1. In contrast, 95&nbsp;% of patients (62/65) in groups 2-4 had GBMs. Treatment was similar in 4 groups (radiotherapy-80&nbsp;%; temozolomide-30&nbsp;%; other chemotherapy-50&nbsp;%). High expression of ASNS, GLS, and BCAT1 were each associated with poor survival in the entire group. The combination of lower ASNS, GLS, and BCAT1 levels correlated with better survival for newly diagnosed GBMs (66 patients; P&nbsp;=&nbsp;0.0039). Only tumors with lower enzymes showed improved outcome with temozolomide. IDH1(WT) gliomas had higher expression of these genes. Manipulation of amino acid metabolism in malignant gliomas may be further studied for therapeutics development

Asparagine Depletion Potentiates the Cytotoxic Effect of Chemotherapy against Brain Tumors

Targeting amino acid metabolism has therapeutic implications for aggressive brain tumors. Asparagine is an amino acid that is synthesized by normal cells. However, some cancer cells lack asparagine synthetase (ASNS), the key enzyme for asparagine synthesis. Asparaginase (ASNase) contributes to eradication of acute leukemia by decreasing asparagine levels in serum and cerebrospinal fluid. However, leukemic cells may become ASNase-resistant by up-regulating ASNS. High expression of ASNS has also been associated with biological aggressiveness of other cancers, including gliomas. Here, the impact of enzymatic depletion of asparagine on proliferation of brain tumor cells was determined. ASNase was used as monotherapy or in combination with conventional chemotherapeutic agents. Viability assays for ASNase-treated cells demonstrated significant growth reduction in multiple cell lines. This effect was reversed by glutamine in a dose-dependent manner -- as expected, because glutamine is the main amino group donor for asparagine synthesis. ASNase treatment also reduced sphere formation by medulloblastoma and primary glioblastoma cells. ASNase-resistant glioblastoma cells exhibited elevated levels of ASNS mRNA. ASNase co-treatment significantly enhanced gemcitabine or etoposide cytotoxicity against glioblastoma cells. Xenograft tumors in vivo showed no significant response to ASNase monotherapy and little response to temozolomide (TMZ) alone. However, combinatorial therapy with ASNase and TMZ resulted in significant growth suppression for an extended duration of time. Taken together, these findings indicate that amino acid depletion warrants further investigation as adjunctive therapy for brain tumors

Anticuerpos antiasparaginasa y actividad asparaginasa en niños con leucemia linfoblástica aguda de alto riesgo Estudio CCG-1961 del Children's Cancer Group

Se investigaron los anticuerpos antiasparaginasa (Ab) y la actividad enzimática de la asparaginasa en los sueros de 1.001 pacientes (CCG-1961) con leucemia linfoblástica aguda de alto riesgo. Los pacientes recibieron nueve dosis de asparaginasa nativa de Escherichia coli durante la inducción. La mitad de los pacientes con respuesta precoz rápida (RPR) fueron asignados aleatoriamente a los brazos de intensidad estándar y siguieron recibiendo asparaginasa nativa. Los demás pacientes con RPR y todos los respondedores tempranos lentos recibieron 6 ó 10 dosis de PEG-asparaginasa. Se analizaron muestras de suero (n = 3.193) para determinar los títulos de anticuerpos antiasparaginasa y la actividad enzimática. Trescientos noventa de 1.001 pacientes (39%) no presentaron elevación de anticuerpos entre las múltiples evaluaciones -es decir, fueron Ab-negativos (1,1). Entre estos 611 pacientes, 447 no presentaron actividad medible de asparaginasa durante el tratamiento. Los pacientes con títulos Ab positivos, pero sin alergias clínicas, siguieron recibiendo asparaginasa de E. coli, cuya actividad disminuyó precipitadamente. No se encontró actividad detectable de asparaginasa en 81 de los 88 pacientes Ab-positivos poco después de las inyecciones de asparaginasa (94% de Ab neutralizante). Los pacientes Ab-positivos con alergias clínicas recibieron posteriormente Erwinase y alcanzaron una actividad sustancial (0,1-0,4 UI/ml). Un análisis provisional de 280 pacientes que fueron seguidos durante 30 meses desde la inducción demostró que los títulos Ab-positivos durante el mantenimiento provisional-1 y en la intensificación diferida-1 se asociaron con una mayor tasa de acontecimientos. El esquema de tratamiento CCG-1961 fue muy inmunogénico, posiblemente debido a la asparaginasa nativa administrada inicialmente. El Ab anti-asparaginasa se asoció con una actividad de asparaginasa indetectable y puede estar correlacionado con resultados adversos en la leucemia linfoblástica aguda de alto riesgo.We investigated the anti-asparaginase antibody (Ab) and asparaginase enzymatic activity in the sera of 1,001 patients (CCG-1961) with high-risk acute lymphoblastic leukemia (HR-ALL). Patients received nine doses of native Escherichia coli asparaginase during induction. Half of rapid early responders (RER) were randomly assigned to standard intensity arms and continued to receive native asparaginase. The other RER patients and all slow early responders received 6 or 10 doses of PEG-asparaginase. Serum samples (n = 3,193) were assayed for determination of asparaginase Ab titers and enzymatic activity. Three hundred ninety of 1,001 patients (39%) had no elevation of Ab among multiple evaluations-that is, were Ab-negative (1.1). Among these 611 patients, 447 had no measurable asparaginase activity during therapy. Patients who were Ab-positive but had no clinical allergies continued to receive E. coli asparaginase, the activity of which declined precipitately. No detectable asparaginase activity was found in 81 of 88 Ab-positive patients shortly after asparaginase injections (94% neutralizing Ab). The Ab-positive patients with clinical allergies subsequently were given Erwinase and achieved substantial activity (0.1-0.4 IU/ml). An interim analysis of 280 patients who were followed for 30 months from induction demonstrated that the Ab-positive titers during interim maintenance-1 and in delayed intensification-1 were associated with an increased rate of events. The CCG-1961 treatment schedule was very immunogenic, plausibly due to initially administrated native asparaginase. Anti-asparaginase Ab was associated with undetectable asparaginase activity and may be correlated with adverse outcomes in HR ALL.Depto. de Farmacología, Farmacognosia y BotánicaFac. de FarmaciaTRUEpu