A Novel Splice Variant of HYAL-4 Drives Malignant Transformation and Predicts Outcome in Patients with Bladder Cancer

Effect of CHST11, a novel biomarker, on the biological functionalities of clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is a common malignant tumor, and the role of carbohydrate sulfotransferase 11 (CHST11) in this cancer remains unclear. Here, by using bioinformatics methods, we comprehensively analyzed the relationship between CHST11 and clinical significance, immune infiltration, functional enrichment, m6A methylation, and protein-protein interaction networks. We found that CHST11 expression was significantly higher in ccRCC samples than in normal tissues. Additionally, CHST11 levels correlated with the clinicopathological features of ccRCC patients and functioned as a prognostic factor for patient survival. Functional analysis revealed the involvement of CHST11 in metabolic pathways. Immune infiltration and m6A methylation analysis suggested the association of CHST11 with immune cell abundance in the tumor microenvironment and specific methylation patterns in ccRCC. The in vitro analysis of the clinical samples and ccRCC cell lines demonstrated that the overexpression of CHST11 promotes ccRCC cell proliferation, migration, and invasion, while its suppression has the opposite effect. Thus, CHST11 may play a remarkable role in the occurrence and progression of ccRCC. Functionally, CHST11 promotes the aggressiveness of ccRCC cells. These findings provide insights into the role of CHST11 in ccRCC progression.Registry and the Registration No. of the study/trial: No. 2021K034.

Key Molecules in Bladder Cancer Affect Patient Prognosis and Immunotherapy Efficacy: Further Exploration for CNTN1 and EMP1

PURPOSE

Immunotherapy has been widely used in bladder cancer (BCa) in recent years and has significantly improved the prognosis of patients with BCa. However, further identification of immunotherapy-sensitive individuals to improve the efficacy of immunotherapy remains an important unmet need.

MATERIALS AND METHODS

The key genes were screened and identified from Gene Expression Omnibus database and The Cancer Genome Atlas database to construct the risk prediction function (risk scores). Real-time polymerase chain reaction, immunohistochemistry, and IMvigor210 data sets were used to verify the roles of key molecules and efficacy of risk scores. The biologic function of CNTN1 and EMP1 was further explored through cell proliferation experiments.

RESULTS

Five key genes, CNTN1, MAP1A, EMP1, MFAP5, and PTGIS, which were significantly related to the prognosis and immune checkpoint molecules of patients, were screened out. CNTN1 and EMP1 were further experimentally confirmed for their significant tumor-promoting effects. Besides, the constructed risk scores on the basis of these five key genes can accurately predict the prognosis and immunotherapy efficacy of patients with BCa. Interestingly, the high-risk patients identified by the risk scores have significantly worse prognosis and immunotherapy effects than low-risk patients.

CONCLUSION

The key genes we screened can affect the prognosis of BCa, tumor microenvironment immune infiltration, and the efficacy of immunotherapy. The risk scores tool we constructed will contribute to the development of individualized treatment for BCa.

Alternative splicing in bladder cancer: potential strategies for cancer diagnosis, prognosis, and treatment

Bladder cancer is the most common malignancy of the urinary tract worldwide. The therapeutic options to tackle this disease comprise surgery, intravesical or systemic chemotherapy, and immunotherapy. Unfortunately, a wide number of patients ultimately become resistant to these treatments and develop aggressive metastatic disease, presenting a poor prognosis. Therefore, the identification of novel therapeutic approaches to tackle this devastating pathology is urgently needed. However, a significant limitation is that the progression and drug response of bladder cancer is strongly associated with its intrinsic molecular heterogeneity. In this sense, RNA splicing is recently gaining importance as a critical hallmark of cancer since can have a significant clinical value. In fact, a profound dysregulation of the splicing process has been reported in bladder cancer, especially in the expression of certain key splicing variants and circular RNAs with a potential clinical value as diagnostic/prognostic biomarkers or therapeutic targets in this pathology. Indeed, some authors have already evidenced a profound antitumor effect by targeting some splicing factors (e.g., PTBP1), mRNA splicing variants (e.g., PKM2, HYAL4-v1), and circular RNAs (e.g., circITCH, circMYLK), which illustrates new possibilities to significantly improve the management of this pathology. This review represents the first detailed overview of the splicing process and its alterations in bladder cancer, and highlights opportunities for the development of novel diagnostic/prognostic biomarkers and their clinical potential for the treatment of this devastating cancer type. This article is categorized under: RNA Processing > Splicing Regulation/Alternative Splicing RNA in Disease and Development > RNA in Disease.

PIWI-interacting RNAs: Critical roles and therapeutic targets in cancer

P-element-induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are a novel class of small regulatory RNAs (approximately 24-31 nucleotides in length) that often bind to members of the PIWI protein family. piRNAs regulate transposons in animal germ cells; piRNAs are also specifically expressed in many human tissues and regulate pivotal signaling pathways. Additionally, the abnormal expression of piRNAs and PIWI proteins has been associated with various malignant tumours, and multiple mechanisms of piRNA-mediated target gene dysregulation are involved in tumourigenesis and progression, suggesting that they have the potential to serve as new biomarkers and therapeutic targets for tumours. However, the functions and potential mechanisms of action of piRNAs in cancer have not yet been elucidated. This review summarises the current findings on the biogenesis, function, and mechanisms of piRNAs and PIWI proteins in cancer. We also discuss the clinical significance of piRNAs as diagnostic or prognostic biomarkers and therapeutic tools for cancer. Finally, we present some critical questions regarding piRNA research that need to be addressed to provide insight into the future development of the field.

The short isoform of MS4A7 is a novel player in glioblastoma microenvironment, M2 macrophage polarization, and tumor progression

BACKGROUND

The unique intracranial tumor microenvironment (TME) contributes to the immunotherapy failure for glioblastoma (GBM), thus new functional protein targets are urgently needed. Alternative splicing is a widespread regulatory mechanism by which individual gene can express variant proteins with distinct functions. Moreover, proteins located in the cell plasma membrane facilitate targeted therapies. This study sought to obtain functional membrane protein isoforms from GBM TME.

METHODS

With combined single-cell RNA-seq and bulk RNA-seq analyses, novel candidate membrane proteins generated by prognostic splicing events were screened within GBM TME. The short isoform of MS4A7 (MS4A7-s) was selected for evaluation by RT-PCR and western blotting in clinical specimens. Its clinical relevance was evaluated in a GBM patient cohort. The function of MS4A7-s was identified by in vitro and in vivo experiments. MS4A7-s overexpression introduced transcriptome changes were analyzed to explore the potential molecular mechanism.

RESULTS

The main expression product, isoform MS4A7-s, generated by exon skipping, is an M2-specific plasma membrane protein playing a pro-oncogenic role in GBM TME. Higher expression of MS4A7-s correlates with poor prognosis in a GBM cohort. In vitro cell co-culture experiments, intracranial co-injection tumorigenesis assay, and RNA-seq suggest MS4A7-s promotes activation of glioma-associated macrophages' (GAMs) PI3K/AKT/GSK3β pathway, leading to M2 polarization, and drives malignant progression of GBM.

CONCLUSIONS

MS4A7-s, a novel splicing isoform of MS4A7 located on the surface of GAMs in GBM TME, is a predictor of patient outcome, which contributes to M2 polarization and the malignant phenotype of GBM. Targeting MS4A7-s may constitute a promising treatment for GBM.

Genome-wide profiling of dysregulated piRNAs and their target genes implicated in oncogenicity of Tongue Squamous Cell Carcinoma

PIWI-interacting RNAs (piRNAs) are single-stranded, 23-36 nucleotide long RNAs that regulate gene expression in the germline but are also detected in some cancers. However, there are no reports yet on piRNA expression in tongue squamous cell carcinoma (TSCC), the most common oral cancer (80-90% percent of all oral cancers). We performed small RNA and whole transcriptome sequencing in H357 tongue cancer and HOK cells (GEO database accession numbers: GSE196674 and GSE196688). We also examined nine published sets of gene expression array data of TSCC tissues from the GEO database to decode piRNAs and their putative targets that may be involved in tumorigenesis. We identified a pool of 16058 and 25677 piRNAs in H357 and HOK, respectively, among which 406 are differentially expressed. We also found that 2094 protein-coding genes are differentially expressed in either TSCC tissues or cell lines. We performed target predictions for these piRNA, pathway and disease function (DF) analyses, as well as qRT-PCR validation of piRNA-target pairs. These experiments revealed one up-regulated (FDFT1) and four down-regulated (OGA, BDH1, TAT, HYAL4) target genes that are enriched in 11 canonical pathways (CPs), with postulated roles in the initiation and progression of TSCC. Downregulation of piR-33422 is predicted to upregulate the FDFT1 gene, which encodes a mevalonate/cholesterol-pathway related farnesyl-diphosphate farnesyltransferase. The FDFT1 appears to be involved in the largest number of oncogenesis-related processes and is interacting with statins, which is a classical cancer drug. This study provides the first evidence of the piRNome of TSCC, which could be investigated further to decode piRNA-mediated gene regulations in malignancy and potential drug targets, such as FDFT1.

Characterization of Hyaluronidase 4 Involved in the Catabolism of Chondroitin Sulfate

Hyaluronidases (HYALs) are endo-beta-N-acetylhexosaminidases that depolymerize not only hyaluronan but also chondroitin sulfate (CS) at the initial step of their catabolism. Although HYAL1 hydrolyzes both CS and HA, HYAL4 is a CS-specific endoglycosidase. The substrate specificity of HYAL4 and identification of amino acid residues required for its enzymatic activity have been reported. In this study, we characterized the properties of HYAL4 including the expression levels in various tissues, cellular localization, and effects of its overexpression on intracellular CS catabolism, using cultured cells as well as mouse tissues. Hyal4 mRNA and HYAL4 protein were demonstrated to be ubiquitously expressed in various organs in the mouse. HYAL4 protein was shown to be present both on cell surfaces as well as in lysosomes of rat skeletal muscle myoblasts, L6 cells. Overexpression of HYAL4 in Chinese hamster ovary cells decreased in the total amount of CS, suggesting its involvement in the cellular catabolism of CS. In conclusion, HYAL4 may be widely distributed and play various biological roles, including the intracellular depolymerization of CS.

Identification of prognostic and immunotherapy-related eRNA ID2-AS1 in bladder cancer

AbstractEnhancer RNAs (eRNAs) can participate in enhancer regulation and target gene transcription, thus affecting the occurrence and development of tumors. In this study, we identified eRNAs closely related to bladder cancer (BLCA). Gene expression profiles and clinical information from The Cancer Genome Atlas (TCGA) database were used in this study. The Atlas of Noncoding RNAs in Cancer (TANRIC) co-expression data was also studied to evaluate correlations between the inferred levels of eRNA and its predicted target genes. Moreover, we evaluated differences in tumor microenvironment between high and low ID2-AS1 expression groups, and predicted the response of high- and low-expression groups to immune checkpoint inhibitor (ICI) treatment. Finally, we analyzed the prognostic value of ID2-AS1 in different tumors. ID2-AS1 and ID2 were identified as eRNAs and target genes related to the prognosis of BLCA. Low ID2-AS1 levels were associated with advanced age, low overall survival, high histological grade, and late BLCA staging. ID2-AS1 appeared to regulate epithelial mesenchymal transition, mitotic spindle assembly, and angiogenesis, thereby affecting BLCA progression. The ID2-AS1 high-expression group had better ICI treatment response. In addition, ID2-AS1 also had prognostic value in other cancers. ID2-AS1 helps predict prognostic and immunotherapeutic effects in BLCA.

Molecular Oncology of Bladder Cancer from Inception to Modern Perspective

Within the last forty years, seminal contributions have been made in the areas of bladder cancer (BC) biology, driver genes, molecular profiling, biomarkers, and therapeutic targets for improving personalized patient care. This overview includes seminal discoveries and advances in the molecular oncology of BC. Starting with the concept of divergent molecular pathways for the development of low- and high-grade bladder tumors, field cancerization versus clonality of bladder tumors, cancer driver genes/mutations, genetic polymorphisms, and bacillus Calmette-Guérin (BCG) as an early form of immunotherapy are some of the conceptual contributions towards improving patient care. Although beginning with a promise of predicting prognosis and individualizing treatments, "-omic" approaches and molecular subtypes have revealed the importance of BC stem cells, lineage plasticity, and intra-tumor heterogeneity as the next frontiers for realizing individualized patient care. Along with urine as the optimal non-invasive liquid biopsy, BC is at the forefront of the biomarker field. If the goal is to reduce the number of cystoscopies but not to replace them for monitoring recurrence and asymptomatic microscopic hematuria, a BC marker may reach clinical acceptance. As advances in the molecular oncology of BC continue, the next twenty-five years should significantly advance personalized care for BC patients.

Dynamic Changes in Myofibroblasts Affect the Carcinogenesis and Prognosis of Bladder Cancer Associated With Tumor Microenvironment Remodeling

Bladder cancer (BLCA) is a tumor that possesses significant heterogeneity, and the tumor microenvironment (TME) plays an important role in the development of BLCA. The TME chiefly consists of tumor cells and tumor-infiltrating immune cells admixed with stromal components. Recent studies have revealed that stromal components, especially cancer-associated fibroblasts (CAFs), affect immune cell infiltration and modulate the extracellular matrix in the TME of BLCA, ultimately impacting the prognosis and therapeutic efficacy of BLCA. Among the subgroups of CAFs, myofibroblasts (myCAFs) were the most abundant and were demonstrated to play an essential role in affecting the prognosis of various tumors, including BLCA. However, the dynamic changes in myCAFs during carcinogenesis and tumor progression have been less discussed previously. With the help of bioinformatics algorithms, we discussed the roles of myCAFs in the carcinogenesis and prognosis of BLCA in this manuscript. Our study highlighted the pathogenesis of BLCA was accompanied by a decrease in the abundance of myCAFs, revealing potential protective properties of myCAFs in the carcinogenesis of BLCA. Meanwhile, the reduced expressions of myCAFs marker genes were highly accurate in predicting tumorigenesis. In contrast, we also demonstrated that myCAFs regulated extracellular matrix remodeling, tumor metabolism, cancer stemness, and oncological mutations, ultimately impacting the treatment responsiveness and prognosis of BLCA patients. Thus, our research revealed the bimodal roles of myCAFs in the development of BLCA, which may be associated with the temporal change of the TME. The in-depth study of myofibroblasts and the TME may provide potential diagnostic biomarkers and therapeutic targets for BLCA.

NFE2L3 promotes tumor progression and predicts a poor prognosis of bladder cancer

The high incidence and vulnerability to recurrence of bladder urothelial carcinoma (BLCA) is a challenge in the clinical. Recent studies have revealed that NFE2L3 plays a vital role in the carcinogenesis and progression of different human tumors. However, the role of NFE2L3 in bladder cancer has not been elucidated. In this study, NFE2L3 expression was significantly increased in bladder cancer samples. Its high expression was associated with advanced clinicopathological characteristics and was an independent prognostic factor for overall survival (OS) and metastasis-free survival (MFS) in 106 patients with BLCA. In vitro and in vivo experiments demonstrated that NFE2L3 knockdown inhibited bladder cancer cells proliferation by inducing the cell cycle arrest and cell apoptosis. Meanwhile, NFE2L3 overexpression promotes BLCA cell migration and invasion in vitro cell lines and in vivo xenografts. Moreover, we identified many genes and pathway alterations associated with tumor progression and metastasis by performing RNA-Seq analysis and functional enrichment of NFE2L3 overexpressing BLCA cells. Mechanistic investigation reveals that overexpression of NFE2L3 promoted epithelial-mesenchymal transition (EMT) in bladder cancer cells with decreased expression of gap junction-associated protein ZO-1 and epithelial marker E-cadherin with the elevation of transcription factors Snail1 and Snail2. Finally, we performed a comprehensive proteomics analysis to explore more potential molecular mechanisms. Our findings revealed that NFE2L3 might serve as a valuable clinical prognostic biomarker and therapeutic target in BLCA.

New Insights Into Human Hyaluronidase 4/Chondroitin Sulphate Hydrolase

In this review, the current experimental evidence, literature and hypotheses surrounding hyaluronidase 4 [HYAL4, also known as chondroitin sulphate hydrolase (CHSE)] and chondroitin sulphate (CS) are explored. Originally named for its sequence similarity to other members of the hyaluronidase family, HYAL4 is actually a relatively distinct member of the family, particularly for its unique degradation of CS-D (2-O-, 6-O-sulphated CS) motifs and specific expression. Human HYAL4 protein expression and structural features are discussed in relation to different isoforms, activities, potential localisations and protein-protein interaction partners. CS proteoglycan targets of HYAL4 activity include: serglycin, aggrecan, CD44 and sulfatase 2, with other potential proteoglycans yet to be identified. Importantly, changes in HYAL4 expression changes in human disease have been described for testicular, bladder and kidney cancers, with gene mutations reported for several others including: leukaemia, endometrial, ovarian, colorectal, head and neck, stomach, lung and breast cancers. The HYAL4 gene also plays a role in P53 negative human cancer cell proliferation and is linked to stem cell naivety. However, its role in cancer remains relatively unexplored. Finally, current tools and techniques for the detection of specific HYAL4 activity in biological samples are critically assessed. Understanding the role of HYAL4 in human diseases will fortify our understanding of developmental processes and disease manifestation, ultimately providing novel diagnostic opportunities and therapeutic targets for drug discovery.

HYAL4-V1/Chondroitinase (Chase) Drives Gemcitabine Resistance and Predicts Chemotherapy Failure in Patients with Bladder Cancer

PURPOSE

Gemcitabine-based chemotherapy regimens are first-line for several advanced cancers. Because of better tolerability, gemcitabine + cisplatin is a preferred neoadjuvant, adjuvant, and/or palliative chemotherapy regimen for advanced bladder cancer. Nevertheless, predicting treatment failure and overcoming resistance remain unmet clinical needs. We discovered that splice variant (V1) of HYAL-4 is a first-in-class eukaryotic chondroitinase (Chase), and CD44 is its major substrate. V1 is upregulated in bladder cancer and drives a malignant phenotype. In this study, we investigated whether V1 drives chemotherapy resistance.

EXPERIMENTAL DESIGN

V1 expression was measured in muscle-invasive bladder cancer (MIBC) specimens by qRT-PCR and IHC. HYAL-4 wild-type (Wt) and V1 were stably expressed or silenced in normal urothelial and three bladder cancer cell lines. Transfectants were analyzed for chemoresistance and associated mechanism in preclinical models.

RESULTS

V1 levels in MIBC specimens of patients who developed metastasis, predicted response to gemcitabine + cisplatin adjuvant/salvage treatment and disease-specific mortality. V1-expressing bladder cells were resistant to gemcitabine but not to cisplatin. V1 expression neither affected gemcitabine influx nor the drug-efflux transporters. Instead, V1 increased gemcitabine metabolism and subsequent efflux of difluorodeoxyuridine, by upregulating cytidine deaminase (CDA) expression through increased CD44-JAK2/STAT3 signaling. CDA inhibitor tetrahydrouridine resensitized V1-expressing cells to gemcitabine. While gemcitabine (25-50 mg/kg) inhibited bladder cancer xenograft growth, V1-expressing tumors were resistant. Low-dose combination of gemcitabine and tetrahydrouridine abrogated the growth of V1 tumors with minimal toxicity.

CONCLUSIONS

V1/Chase drives gemcitabine resistance and potentially predicts gemcitabine + cisplatin failure. CDA inhibition resensitizes V1-expressing tumors to gemcitabine. Because several chemotherapy regimens include gemcitabine, our study could have broad significance.