Emerging Role of Biomarkers in Testicular Germ Cell Tumors

Subgrouping testicular germ cell tumors based on immunotherapy and chemotherapy associated lncRNAs

Testicular germ cell tumors (TGCT) are the most common reproductive system malignancies in men aged 15-44 years, accounting for 95 % of all testicular tumors. Our previous studies have been shown that long non-coding RNAs (lncRNAs), such as LINC00313, TTTY14 and RFPL3S, were associated with development of TGCT. Subgrouping TGCT according to differential expressed lncRNAs and immunological characteristics is helpful to comprehensively describe the characteristics of TGCT and implement precise treatment. In this study, the TGCT transcriptome data in The Cancer Genome Atlas Program (TCGA) database was used to perform consensus clustering analysis to construct a prognostic model for TGCT. TGCT was divided into 3 subtypes C1, C2, and C3 based on the differentially expressed lncRNAs. C1 subtype was sensitive to chemotherapy drugs, while the C2 subtype was not sensitive to chemotherapy drugs, and C3 subtype may benefit from immunotherapy. We defined the C1 subtype as epidermal progression subtype, the C2 subtype as mesenchymal progression subtype, and the C3 subtype as T cell activation subtype. Subgrouping based on differentially expressed genes (DEGs) and immunological characteristics is helpful for the precise treatment of TGCT.

The Role of miRNA in Testicular Cancer: Current Insights and Future Perspectives

Background and Objectives: Despite advancements in the diagnosis and treatment of testicular germ cell tumours (TGTCs), challenges persist in identifying reliable biomarkers for early detection and precise disease management. This narrative review addresses the role of microRNAs (miRNAs) as potential diagnostic tools and therapeutic targets in the treatment of TGCTs. Materials and Methods: Three databases (PubMed®, Web of Science™, and Scopus®) were queried for studies investigating the utility of miRNA as diagnostic tools, assessing their prognostic significance, and evaluating their potential to guide TGCT treatment. Different combinations of the following keywords were used, according to a free-text protocol: "miRNA", "non-coding RNA", "small RNA", "Testicular Cancer", "seminomatous testicular germ cell", "non-seminomatous testicular germ cell". Results: The potential of miRNAs as possible biomarkers for a non-invasive diagnosis of TGCT is appealing. Their integration into the diagnostic pathway for TGCT patients holds the potential to enhance the discriminative power of conventional serum tumour markers (STMs) and could expedite early diagnosis, given that miRNA overexpression was observed in 50% of GCNIS cases. Among miRNAs, miR-371a-3p stands out with the most promising evidence, suggesting its relevance in the primary diagnosis of TGCT, particularly when conventional STMs offer limited value. Indeed, it demonstrated high specificity (90-99%) and sensitivity (84-89%), with good positive predictive value (97.2%) and negative predictive value (82.7%). Furthermore, a direct relationship between miRNA concentration, disease burden, and treatment response exists, regardless of disease stages. The initial evidence of miRNA decrease in response to surgical treatment and systemic chemotherapy has been further supported by more recent results suggesting the potential utility of this tool not only in evaluating treatment response but also in monitoring residual disease and predicting disease relapse. Conclusions: MiRNAs could represent a reliable tool for accurate diagnosis and disease monitoring in the treatment of TGCT, providing more precise tools for early detection and treatment stratification. Nevertheless, well-designed clinical trials and comprehensive long-term data are needed to ensure their translation into effective clinical tools.

Breaking the Mold: Epigenetics and Genomics Approaches Addressing Novel Treatments and Chemoresponse in TGCT Patients

Testicular germ-cell tumors (TGCT) have been widely recognized for their outstanding survival rates, commonly attributed to their high sensitivity to cisplatin-based therapies. Despite this, a subset of patients develops cisplatin resistance, for whom additional therapeutic options are unsuccessful, and ~20% of them will die from disease progression at an early age. Several efforts have been made trying to find the molecular bases of cisplatin resistance. However, this phenomenon is still not fully understood, which has limited the development of efficient biomarkers and precision medicine approaches as an alternative that could improve the clinical outcomes of these patients. With the aim of providing an integrative landscape, we review the most recent genomic and epigenomic features attributed to chemoresponse in TGCT patients, highlighting how we can seek to combat cisplatin resistance through the same mechanisms by which TGCTs are particularly hypersensitive to therapy. In this regard, we explore ongoing treatment directions for resistant TGCT and novel targets to guide future clinical trials. Through our exploration of recent findings, we conclude that epidrugs are promising treatments that could help to restore cisplatin sensitivity in resistant tumors, shedding light on potential avenues for better prognosis for the benefit of the patients.

An update on diagnostic tissue-based biomarkers in testicular tumors

Testicular cancer is rare overall but comprises the most common solid malignancy diagnosed in young men aged ∼20-40 years. Most testicular neoplasms generally fall into 2 broad categories: germ cell tumors (GCTs; ∼95%) and sex cord-stromal tumors (SCSTs ∼5%). Given the relative rarity of these tumors, diagnostic biomarkers are highly relevant for their diagnosis. Over the past several decades, diagnostic biomarkers have improved dramatically through targeted immunohistochemical and molecular characterization. Despite these recent advances, most markers are not perfectly sensitive or entirely specific. Therefore, they need to be used in combination and interpreted in context. In this review, we summarize tissue-based biomarkers relevant to the pathologist, with a focus on practical diagnostic issues that relate to testicular GCT and SCST.

Comprehensive Analysis Identifies Ameloblastin-Related Competitive Endogenous RNA as a Prognostic Biomarker for Testicular Germ Cell Tumour

Simple Summary

Testicular germ cell tumour is a common tumour in young males, and although it is one of the most curable cancers, many patients still experience recurrence after the chemotherapy. Tumour recurrence is not detected with high sensitivity by established blood tumour markers. Ameloblastin is identified as an extracellular matrix protein and has shown to be associated with tumour progression. We validated ameloblastin’s expression in testicular tissue, and used comprehensive bioinformatics analysis of 156 patients with testicular germ cell tumour to show that the level of ameloblastin was associated with the time of tumour recurrence after the first cure. In the analysis of ameloblastin differential genes in the tumour, a ceRNA (competing endogenous RNA) regulatory network associated with tumour diagnosis and an independent prognostic factor for the tumour, PELATON (Plaque Enriched LncRNA In Atherosclerotic And Inflammatory Bowel Macrophage Regulation), were identified, which could provide evidence for prediction of tumour prognosis.

Abstract

Testicular Germ Cell Tumour (TGCT) is one of the most common tumours in young men. Increasing evidence shows that the extracellular matrix has a key role in the prognosis and metastasis of various human cancers. This study analysed the relationship between the matrix protein ameloblastin (AMBN) and potential biological markers associated with TGCT diagnosis and prognosis. The relationship between AMBN and TGCT prognosis was determined by bioinformatic analysis using the expression profiles of three RNAs (long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and mRNAs) from The Cancer Genome Atlas (TCGA) database, and available clinical information of the corresponding patients. Prediction and validation of competitive endogenous RNA (ceRNA) regulatory networks related to AMBN was performed. AMBN and its associated ceRNA regulatory network were found to be related to the recurrence of TGCT, and LINC02701 may be used as a diagnostic factor in TGCT. Furthermore, we identified PELATON (Plaque Enriched LncRNA In Atherosclerotic And Inflammatory Bowel Macrophage Regulation) as an independent prognostic factor for TGCT progression-free interval.