MicroRNA-profiling of miR-371~373- and miR-302/367-clusters in serum and cerebrospinal fluid identify patients with intracranial germ cell tumors

Current Role of MicroRNAs in the Diagnosis and Clinical Management of Germ Cell Tumors

Germ cell tumors (GCTs) are a rare and heterogeneous group of neoplasms arising from primitive germ cells. MicroRNAs are small noncoding RNAs that have emerged as potential cancer biomarkers in the last decade. In particular, miR-371a-3p has shown good diagnostic performance for germ cell neoplasia in situ-derived testicular GCTs in several well-established cohorts and is expected to enter the clinical arena in the near future. GCTs universally exhibit high expression of miR-371-373 and miR-302/367 clusters and low expression of let-7 family miRNAs. Further studies are needed to assess the potential role of these miRNAs as biomarkers of ovarian and extragonadal GCTs.

Intracranial germ cell tumors: advancement in genomic diagnostics and the need for novel therapeutics

Introduction

The outcomes for patients with intracranial germ cell tumors (GCT) has improved over the past few decades. However, there remains a lack of a consensus on a standard diagnostic and treatment approach of these tumors. The diagnostic work-up of intracranial GCT remains variable, and the treatment for patients with recurrent disease remains challenging.

Methods

We review the current approach in the diagnosis and treatment of intracranial GCT. Given the heterogeneity of these tumors, we highlight the challenges and controversy with these conventional approaches.

Results

We discuss the advancements in the understanding of the underlying genetic changes in intracranial GCT and the utility of novel molecular techniques in the diagnosis and classification of intracranial germ cell tumors as well as development of potential novel therapeutics.

Discussion

Development of liquid biopsy platforms for diagnosis and management of malignancies is a rapidly growing field. Current approach utilizing traditional tumor markers have significant limitations. In this review, we will discuss profiling of intracranial GCTs for genetic and epigenetic signatures, which are emerging as promising biomarkers to assist in the diagnosis and management of intracranial GCTs. Various studies have shown that activating mutations in MAPK pathway are common alterations in intracranial GCTs, with KIT expression seen in most germinomas. Development of targeted therapeutics against KIT has led to the prospect of targeted therapy in germinoma. Other treatment modalities being considered for clinical development include immunotherapy and the use of immune checkpoint inhibitors, especially in NGGCT. In this review, we will discuss the potential novel therapeutics and the clinical trials that are currently under development.

Pediatric Suprasellar Tumors: Unveiling the Mysteries of Craniopharyngioma and Germ Cell Tumors-Insights From Diagnosis to Advanced Therapeutics

BACKGROUND

Pediatric suprasellar tumors represent a unique and intricate challenge in the landscape of pediatric neuro-oncology.

METHODS

We conducted an in-depth literature review, focusing on large clinical trials and major publications in pediatric suprasellar tumors, particularly craniopharyngiomas and germ cell tumors, to provide a comprehensive perspective on the challenges in the diagnosis, treatment, and molecular aspects of these tumors.

RESULTS

Nestled within the critical confines of the suprasellar region, these tumors manifest against the backdrop of crucial growth and developmental processes. The suprasellar region, housing the pituitary gland and surrounding structures, plays a pivotal role in orchestrating hormonal regulation and growth. The emergence of tumors within this delicate terrain introduces a complex array of challenges, encompassing neurological, endocrinological, and developmental dimensions from damage to the hypothalamic-pituitary axis.

CONCLUSIONS

This article provides a thorough exploration of pediatric craniopharyngiomas and germ cell tumors, elucidating their clinical presentations, treatment modalities, and outcomes. The focused analysis aims to deepen our understanding of these tumors by offering insights for refined clinical management and improved patient outcomes.

A comprehensive overview of liquid biopsy applications in pediatric solid tumors

Liquid biopsies are emerging as an alternative source for pediatric cancer biomarkers with potential applications during all stages of patient care, from diagnosis to long-term follow-up. While developments within this field are reported, these mainly focus on dedicated items such as a specific liquid biopsy matrix, analyte, and/or single tumor type. To the best of our knowledge, a comprehensive overview is lacking. Here, we review the current state of liquid biopsy research for the most common non-central nervous system pediatric solid tumors. These include neuroblastoma, renal tumors, germ cell tumors, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma and other soft tissue sarcomas, and liver tumors. Within this selection, we discuss the most important or recent studies involving liquid biopsy-based biomarkers, anticipated clinical applications, and the current challenges for success. Furthermore, we provide an overview of liquid biopsy-based biomarker publication output for each tumor type based on a comprehensive literature search between 1989 and 2023. Per study identified, we list the relevant liquid biopsy-based biomarkers, matrices (e.g., peripheral blood, bone marrow, or cerebrospinal fluid), analytes (e.g., circulating cell-free and tumor DNA, microRNAs, and circulating tumor cells), methods (e.g., digital droplet PCR and next-generation sequencing), the involved pediatric patient cohort, and proposed applications. As such, we identified 344 unique publications. Taken together, while the liquid biopsy field in pediatric oncology is still behind adult oncology, potentially relevant publications have increased over the last decade. Importantly, steps towards clinical implementation are rapidly gaining ground, notably through validation of liquid biopsy-based biomarkers in pediatric clinical trials.

Plasma miRNA expression profile in pediatric pineal pure germinomas

Background

Pure germinomas account for 40% of pineal tumors and are characterized by the lack of appreciable tumor markers, thus requiring a tumor biopsy for diagnosis. MicroRNAs (miRNA) have emerged as potential non-invasive biomarkers for germ cell tumors and may facilitate the non-invasive diagnosis of pure pineal germinomas.

Material and methods

A retrospective chart review was performed on all patients treated at the Children's Cancer Hospital Egypt diagnosed with a pineal region tumor between June 2013 and March 2021 for whom a research blood sample was available. Plasma samples were profiled for miRNA expression, and DESeq2 was used to compare between pure germinoma and other tumor types. Differentially expressed miRNAs were identified. The area under the curve of the receive;r operating characteristic curve was constructed to evaluate diagnostic performance.

Results

Samples from 39 pediatric patients were available consisting of 12 pure germinomas and 27 pineal region tumors of other pathologies, including pineal origin tumors [n = 17; pineoblastoma (n = 13) and pineal parenchymal tumors of intermediate differentiation (n = 4)] and others [n = 10; low-grade glioma (n = 6) and atypical teratoid rhabdoid tumor (n = 4)]. Using an adjusted p-value <0.05, three miRNAs showed differential expression (miR-143-3p, miR-320c, miR-320d; adjusted p = 0.0058, p = 0.0478, and p = 0.0366, respectively) and good discriminatory power between the two groups (AUC 90.7%, p < 0.001) with a sensitivity of 25% and a specificity of 100%.

Conclusion

Our results suggest that a three-plasma miRNA signature has the potential to non-invasively identify pineal body pure germinomas which may allow selected patients to avoid the potential surgical complications.

Final report of the phase II NEXT/CNS-GCT-4 trial: GemPOx followed by marrow-ablative chemotherapy for recurrent intracranial germ cell tumors

Background

Patients with relapsed intracranial germinoma can achieve durable remission with standard chemotherapy regimens and/or reirradiation; however, innovative therapies are required for patients with relapsed and/or refractory intracranial nongerminomatous germ cell tumors (NGGCTs) due to their poor prognosis. Improved outcomes have been reported using reinduction chemotherapy to achieve minimal residual disease, followed by marrow-ablative chemotherapy (HDCx) with autologous hematopoietic progenitor cell rescue (AuHPCR). We conducted a phase II trial evaluating the response and toxicity of a 3-drug combination developed for recurrent intracranial germ cell tumors consisting of gemcitabine, paclitaxel, and oxaliplatin (GemPOx).

Methods

A total of 9 patients with confirmed relapsed or refractory intracranial GCT were enrolled after signing informed consent, and received at least 2 cycles of GemPOx, of which all but 1 had relapsed or refractory NGGCTs. One patient with progressive disease was found to have pathologically confirmed malignant transformation to pure embryonal rhabdomyosarcoma (without GCT elements), hence was ineligible and not included in the analysis. Patients who experienced sufficient responses proceeded to receive HDCx with AuHPCR. Treatment response was determined based on radiographic tumor assessments and tumor markers.

Results

A total of 7 patients achieved sufficient response and proceeded with HDCx and AuHPCR, and 5 subsequently received additional radiotherapy. A total of 2 patients developed progressive disease while receiving GemPOx. Myelosuppression and transaminitis were the most common treatment-related adverse events. With a mean follow-up of 44 months, 4 patients (3 NGGCTs, 1 germinoma) are alive without evidence of disease.

Conclusions

GemPOx demonstrates efficacy in facilitating stem cell mobilization, thus facilitating the feasibility of both HDCx and radiotherapy.

Application of microRNAs in the diagnosis and monitoring of pediatric germ cell tumors: Kazakh experience

GCT is characterized by specific biochemical markers expression, such as human chorionic gonadotropin (hCG) and alpha-fetoprotein (AFP), which are the main tools in the diagnosis and monitoring of GCT treatment. They are expressed in 15-20% of cases of seminoma and in 60-80% of cases of non-seminoma. MicroRNA profiling allows to identify a number of microRNAs that are superior to classical serum tumor markers in the diagnosis of primary tumors, as well as in subsequent monitoring and prediction of recurrence. We analyzed the expression of 9 microRNAs (microRNA clusters 302/367 and 371-373, microRNA375) in the blood serum of 20 children with extracranial GCT at different stages of therapy and showed their usefulness and informativeness in early detection of events. Taking into consideration the high sensitivity and specificity, serum microRNAs 367,371,372,373,302d are of great interest for clinical use in malignant GCT. Significant expression of miR 375-3p was not detected either in malignant GCT or in teratomas.

Stalking the stalk: Isolated pituitary stalk thickening and predictive factors for proliferative disease

Background

Few studies have evaluated predictive factors of isolated pituitary stalk thickening (iPST) in children.

Methods

In this retrospective study, radiology, endocrinology, and neuro-oncology databases were interrogated to identify patients with iPST between January 2000 and June 2019. A blinded, longitudinal assessment of MRIs was performed using quantitative, semi-quantitative, and qualitative metrics. Neuroimaging parameters were correlated to clinical parameters.

Results

Forty-seven patients were identified, with 40 meeting the inclusion criteria. Median age at baseline MRI was 9.6 years (range 0.9-17.5) with median follow-up of 5.2 years (range 0.3-18.6). Twenty-five (63%) were female. Thirty-four (85%) had pituitary dysfunction, including 31 with central diabetes insipidus (cDI). cDI was not predictive of proliferative disease (PfD): 69% of those with presumed primary hypophysitis (PPH) versus 93% with PfD (P = .1). Fourteen (35%) patients were diagnosed with PfD (germinoma = 8, Langerhans cell histiocytosis = 5, lymphoma = 1) at median of 1.3 years (range 0.3-4.0) after initial MRI. Progressive thickening of the stalk over time was associated with PfD (86% vs 4% in PPH, P < .0001), as was thickening of the entire stalk (56% in PfD vs 27% in PPH, P < .0001) with different imaging trends over time observed in PfD versus PPH. A "sack of marbles" appearance with heterogeneous enhancement on post-contrast imaging was associated with germinoma.

Conclusions

In this cohort, 35% of children with iPST were diagnosed with PfD. The association of cDI and PfD was not statistically significant. Progressive thickening of the entire stalk was predictive of PfD and a "sack of marbles" pattern was found to be highly suggestive of germinoma.

Advances in genetic abnormalities, epigenetic reprogramming, and immune landscape of intracranial germ cell tumors

Intracranial germ cell tumors (IGCTs) are a rare subtype of central nervous system neoplasms that predominantly affect young individuals and exhibit a higher incidence in East Asia. IGCTs can be pathologically divided into two main categories: germinomas and non-germinomatous germ cell tumors (NGGCTs). Despite the scarcity of this disease, recent advancements in molecular biology techniques have facilitated the discovery of the inherent genetic and molecular characteristics of IGCTs. Somatic mutations that result in the activation of the KIT/RAS/MAPK and PI3K/AKT/mTOR pathways, chromosomal instability leading to characteristic changes in chromosomal fragments (notably 12p gain), and potentially diagnostic miRNAs (such as miR-371a-3p) may provide valuable insights for the efficient diagnosis, targeted therapy, and prognosis evaluation of IGCTs. Additionally, transcriptomic and methylomic analyses have provided new perspectives on the intrinsic development of IGCTs, further elucidating their equivalence with GCTs at other sites. The evaluation of the tumor immune landscape may guide prognosis prediction and immunotherapy for IGCT patients. Nevertheless, current research still faces challenges such as the absence of basic laboratory research systems, a single source of large sample research data, and a limited overall volume of research. The incorporation of larger sample sizes, the implementation of more innovative evaluation systems, and the employment of novel experimental methods are urgently required to become the focus of future research.

Incidence and Predictors for Oncologic Etiologies in Chinese Children with Pituitary Stalk Thickening

BACKGROUND

With the increasing use of magnetic resonance imaging (MRI) in the evaluation of children with endocrine disorders, pituitary stalk thickening (PST) poses a clinical conundrum due to the potential for underlying neoplasms and challenges in obtaining a tissue biopsy. The existing literature suggests Langerhans cell histiocytosis (LCH) to be the commonest (16%) oncologic cause for PST, followed by germ cell tumors (GCTs, 13%) (CCLG 2021). As the cancer epidemiology varies according to ethnicity, we present herein the incidence and predictors for oncologic etiologies in Hong Kong Chinese children with PST.

METHODS

Based on a territory-wide electronic database, we reviewed patients aged < 19 years who presented to three referral centers with endocrinopathies between 2010 and 2022. Records for patients who underwent at least one MRI brain/pituitary were examined (n = 1670): those with PST (stalk thickness ≥ 3 mm) were included, while patients with pre-existing cancer, other CNS and extra-CNS disease foci that were diagnostic of the underlying condition were excluded.

RESULTS

Twenty-eight patients (M:F = 10:18) were identified. The median age at diagnosis of PST was 10.9 years (range: 3.8-16.5), with central diabetes insipidus (CDI) and growth hormone deficiency (GHD) being the most frequent presenting endocrine disorders. At a median follow-up of 4.8 years, oncologic diagnoses were made in 14 patients (50%), including 13 GCTs (46%; germinoma = 11, non-germinoma = 2) and one LCH (4%). Among patients with GCTs, 10 were diagnosed based on histology, two by abnormal tumor markers and one by a combination of histology and tumor markers. Three patients with germinoma were initially misdiagnosed as hypophysitis/LCH. The cumulative incidence of oncologic diagnoses was significantly higher in boys and patients with PST at presentation ≥6.5 mm, CDI or ≥2 pituitary hormone deficiencies at presentation and evolving hypopituitarism (all p < 0.05 by log-rank).

CONCLUSIONS

A higher rate of GCTs was observed in Chinese children with endocrinopathy and isolated PST. The predictors identified in this study may guide healthcare providers in Asia in clinical decision making. Serial measurement of tumor markers is essential in management.

Epigenetic Factors and ncRNAs in Testicular Cancer

Testicular cancer is the most prevalent tumor among males aged 15 to 35, resulting in a significant number of newly diagnosed cases and fatalities annually. Non-coding RNAs (ncRNAs) have emerged as key regulators in various cellular processes and pathologies, including testicular cancer. Their involvement in gene regulation, coding, decoding, and overall gene expression control suggests their potential as targets for alternative treatment approaches for this type of cancer. Furthermore, epigenetic modifications, such as histone modifications, DNA methylation, and the regulation by microRNA (miRNA), have been implicated in testicular tumor progression and treatment response. Epigenetics may also offer critical insights for prognostic evaluation and targeted therapies in patients with testicular germ cell tumors (TGCT). This comprehensive review aims to present the latest discoveries regarding the involvement of some proteins and ncRNAs, mainly miRNAs and lncRNA, in the epigenetic aspect of testicular cancer, emphasizing their relevance in pathogenesis and their potential, given the fact that their specific expression holds promise for prognostic evaluation and targeted therapies.

Aberrant Methylation of the Imprinted C19MC and MIR371-3 Clusters in Patients with Non-Small Cell Lung Cancer

Epigenetic mechanisms have emerged as an important contributor to tumor development through the modulation of gene expression. Our objective was to identify the methylation profile of the imprinted C19MC and MIR371-3 clusters in patients with non-small cell lung cancer (NSCLC) and to find their potential target genes, as well as to study their prognostic role. DNA methylation status was analyzed in a NSCLC patient cohort (n = 47) and compared with a control cohort including COPD patients and non-COPD subjects (n = 23) using the Illumina Infinium Human Methylation 450 BeadChip. Hypomethylation of miRNAs located on chromosome 19q13.42 was found to be specific for tumor tissue. We then identified the target mRNA-miRNA regulatory network for the components of the C19MC and MIR371-3 clusters using the miRTargetLink 2.0 Human tool. The correlations of miRNA-target mRNA expression from primary lung tumors were analyzed using the CancerMIRNome tool. From those negative correlations identified, we found that a lower expression of 5 of the target genes (FOXF2, KLF13, MICA, TCEAL1 and TGFBR2) was significantly associated with poor overall survival. Taken together, this study demonstrates that the imprinted C19MC and MIR371-3 miRNA clusters undergo polycistronic epigenetic regulation leading to deregulation of important and common target genes with potential prognostic value in lung cancer.

Primary central nervous system germ cell tumors in children and young adults: A review of controversies in diagnostic and treatment approach

Primary central nervous system (CNS) germ cell tumors (GCT) are a rare heterogenous group of cancers, arising most commonly in the second decade of life. Through several clinical trials conducted around the world by various groups, the treatment approach for CNS GCT has advanced substantially with generally improved overall outcomes. In recent years, the goal of clinical trials has been focused on reduction of the radiotherapy burden and minimization of long-term toxicity. This review summarizes the current diagnostic and treatment regimens for CNS GCT, examines the controversies associated with these approaches, gaps in contemporary knowledge, and underscores the challenges we face. We also explore future directions in the management of CNS GCT with the ultimate overall aim of preserving curative outcomes, identifying novel biomarkers, and mitigating neurocognitive, endocrine, and psychological toxicity through prospective clinical studies.