Rb knockdown accelerates bladder cancer progression through E2F3 activation

FTO promotes the progression of retinoblastoma through YTHDF2-dependent N6-methyladenosine modification in E2F3

Early treatment of retinoblastoma (RB) has significantly improved clinical outcomes. N6-methyladenosine (m6A) methylation is crucial for cancer progression. Thus, we investigated the role of FTO-dependent demethylation in RB and its underlying mechanisms. The biological behavior of RB cells was analyzed using cell counting kit-8, colony formation analysis, transwell assay, flow cytometry, and western blot analysis. m6A modification was evaluated using methylated RNA immunoprecipitation and dual-luciferase reporter assays, and E2F3 stability was assessed using Actinomycin D. The roles of FTO and E2F3 were also elucidated in vivo. These results indicated that FTO was highly expressed in RB cells with low m6A levels. FTO knockdown inhibited RB cell growth, migration, invasion, and epithelial-mesenchymal transition and arrested the cell cycle at the G0/G1 phase. Mechanistically, FTO interference promoted m6A methylation of E2F3, which was recognized by YTHDF2, thereby reducing mRNA stability. E2F3 overexpression partially rescued the effects of FTO knockdown on biological behavior. Moreover, FTO knockdown reduced tumor weight, tumor volume, ki67 expression, and tumor cell infiltration by mediating E2F3. Taken together, FTO silencing inhibited the malignant processes of RB by suppressing E2F3 in an m6A-YTHD2-dependent manner. These findings suggest that FTO is a novel therapeutic target for RB.

Immunomodulatory effects and mechanisms of the extracts and secondary compounds of Zingiber and Alpinia species: a review

Zingiber and Alpinia species (family: Zingiberaceae) are popularly used in food as spices and flavoring agents and in ethnomedicine to heal numerous diseases, including immune-related disorders. However, their ethnomedicinal uses have not been sufficiently supported by scientific investigations. Numerous studies on the modulating effects of plants and their bioactive compounds on the different steps of the immune system have been documented. This review aimed to highlight up-to-date research findings and critically analyze the modulatory effects and mechanisms of the extracts and secondary compounds of several Zingiber and Alpinia species, namely, Zingiber officinale Roscoe, Z. cassumunar Roxb., Z. zerumbet (L.) Roscoe ex Sm., Alpinia galanga Linn., A. conchigera Griff, A. katsumadai Hayata, A. oxyphylla Miq., A. officinarum Hance, A. zerumbet (Pers.) Burtt. et Smith, and A. purpurata (Viell.) K. Schum. on the immune system, particularly via the inflammation-related signaling pathways. The immunomodulating activities of the crude extracts of the plants have been reported, but the constituents contributing to the activities have mostly not been identified. Among the extracts, Z. officinale extracts were the most investigated for their in vitro, in vivo, and clinical effects on the immune system. Among the bioactive metabolites, 6-, 8-, and 10-gingerols, 6-shogaol, and zerumbone from Zingiber species and cardamomin, 1'-acetoxychavicol acetate, yakuchinone, rutin, 1,8-cineole, and lectin from Alpinia species have demonstrated strong immunomodulating effects. More experimental studies using cell and animal models of immune-related disorders are necessary to further understand the underlying mechanisms, together with elaborate preclinical pharmacokinetics, pharmacodynamics, bioavailability, and toxicity studies. Many of these extracts and secondary metabolites are potential candidates for clinical development in immunomodulating agents or functional foods to prevent and treat chronic inflammatory disorders.

Genetic analysis of human RNA binding motif protein 48 (RBM48) reveals an essential role in U12-type intron splicing

U12-type or minor introns are found in most multicellular eukaryotes and constitute ∼0.5% of all introns in species with a minor spliceosome. Although the biological significance for the evolutionary conservation of U12-type introns is debated, mutations disrupting U12 splicing cause developmental defects in both plants and animals. In human hematopoietic stem cells, U12 splicing defects disrupt proper differentiation of myeloid lineages and are associated with myelodysplastic syndrome, predisposing individuals to acute myeloid leukemia. Mutants in the maize ortholog of RNA binding motif protein 48 (RBM48) have aberrant U12-type intron splicing. Human RBM48 was recently purified biochemically as part of the minor spliceosome and shown to recognize the 5' end of the U6atac snRNA. In this report, we use CRISPR/Cas9-mediated ablation of RBM48 in human K-562 cells to show the genetic function of RBM48. RNA-seq analysis comparing wild-type and mutant K-562 genotypes found that 48% of minor intron-containing genes have significant U12-type intron retention in RBM48 mutants. Comparing these results to maize rbm48 mutants defined a subset of minor intron-containing genes disrupted in both species. Mutations in the majority of these orthologous minor intron-containing genes have been reported to cause developmental defects in both plants and animals. Our results provide genetic evidence that the primary defect of human RBM48 mutants is aberrant U12-type intron splicing, while a comparison of human and maize RNA-seq data identifies candidate genes likely to mediate mutant phenotypes of U12-type splicing defects.

Single-cell RNAseq and longitudinal proteomic analysis of a novel semi-spontaneous urothelial cancer model reveals tumor cell heterogeneity and pretumoral urine protein alterations

Bladder cancer, one of the most prevalent malignancies worldwide, remains hard to classify due to a staggering molecular complexity. Despite a plethora of diagnostic tools and therapies, it is hard to outline the key steps leading up to the transition from high-risk non-muscle-invasive bladder cancer (NMIBC) to muscle-invasive bladder cancer (MIBC). Carcinogen-induced murine models can recapitulate urothelial carcinogenesis and natural anti-tumor immunity. Herein, we have developed and profiled a novel model of progressive NMIBC based on 10 weeks of OH-BBN exposure in hepatocyte growth factor/cyclin dependent kinase 4 (R24C) (Hgf-Cdk4R24C) mice. The profiling of the model was performed by histology grading, single cell transcriptomic and proteomic analysis, while the derivation of a tumorigenic cell line was validated and used to assess in vivo anti-tumor effects in response to immunotherapy. Established NMIBC was present in females at 10 weeks post OH-BBN exposure while neoplasia was not as advanced in male mice, however all mice progressed to MIBC. Single cell RNA sequencing analysis revealed an intratumoral heterogeneity also described in the human disease trajectory. Moreover, although immune activation biomarkers were elevated in urine during carcinogen exposure, anti-programmed cell death protein 1 (anti-PD1) monotherapy did not prevent tumor progression. Furthermore, anti-PD1 immunotherapy did not control the growth of subcutaneous tumors formed by the newly derived urothelial cancer cell line. However, treatment with CpG-oligodeoxynucleotides (ODN) significantly decreased tumor volume, but only in females. In conclusion, the molecular map of this novel preclinical model of bladder cancer provides an opportunity to further investigate pharmacological therapies ahead with regards to both targeted drugs and immunotherapies to improve the strategies of how we should tackle the heterogeneous tumor microenvironment in urothelial bladder cancer to improve responses rates in the clinic.

Immune checkpoint inhibitors for BCG-resistant NMIBC: the dawn of a new era

INTRODUCTION

High risk non-muscle invasive bladder cancer (NMIBC) is a recurring and potentially lethal disease. To date, with the exception of radical surgery, there are no validated strategies for patients not responding to intravesical BCG therapy. Immune checkpoint inhibitors (ICI) are currently being tested for BCG-resistant NMIBC. We report current available data and ongoing trials exploring the efficacy and safety of ICI in this setting.

EVIDENCE ACQUISITION

A narrative search was performed including the combination of the following words: ("immunotherapy") AND ("BCG" AND "resistant" OR "non-muscle AND invasive") AND ("bladder AND "cancer"). Three search engines: PubMed, Embase and Web of Science were queried up to November 1, 2020. Congress abstracts reporting results and not only trials' design were also referenced. The US National Library of Medicine was queried via clinicaltrials.gov to explore ongoing trials on the subject.

EVIDENCE SYNTHESIS

Pembrolizumab demonstrated a promising 40.6% (95% CI: 30.7-51.1) complete response within the KEYNOTE-057, with a median duration of response of 16.2 months. Preliminary data in the phase II SWOG S1605 trial with atezolizumab showed a 41.1% complete response at 3 months. Avelumab is being tested in the PREVERT phase II study exploring ICI with radiotherapy (60-66 Gy) of the whole bladder. CheckMate 9UT analyzes nivolumab monotherapy versus nivolumab + BMS-986205 (IDO-1 inhibitor) with or without BCG in patients with BCG-unresponsive, carcinoma in situ with or without papillary component. Finally, durvalumab is being studied in the BCG resistant space with radiotherapy in the ADAPT-BLADDER study. After proving its safety profile in the phase 1, the trial will randomize patients to durvalumab + BCG, durvalumab + radiation therapy (6Gy 3×) or BCG rechallenge.

CONCLUSIONS

Pembrolizumab has received FDA approval in the treatment of BCG-resistant NMIBC. All five other ICI molecules are currently being extensively tested within clinical trials. The results of the currently ongoing studies are awaited with impatience by the uro-oncologic community and will probably open a new era in the treatment of BCG-resistant NMIBC.

CircularRNA_0119872 regulates the microRNA-582-3p/E2F transcription factor 3 pathway to promote the progression of malignant melanoma

OBJECTIVES

Malignant melanoma (MM) is an invasive tumor that poses a threat to patient health. Circular RNAs (circRNAs) are important regulators of MM carcinogenesis. In this study, we investigated the expression characteristics and biological functions of, and mechanism underlying, circ_0119872 expression in MM.

METHODS

Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was employed to examine the circ_0119872, microRNA (miR)-582-3p, and E2F transcription factor 3 (E2F3) mRNA expression levels in MM tissues and cell lines. Western blotting was performed to quantify E2F3 protein expression. MM cells with circ_0119872 knockdown were established, and cell counting kit 8 (CCK-8) and transwell assays were utilized to examine the function of circ_0119872 and its effects on the malignant characteristics of MM cells. The MiRDB and TargetScan databases were used to predict the target genes of miR-582-3p. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was used to explore the biological functions of the target genes of miR-582-3p. Additionally, a dual-luciferase reporter gene experiment was performed to verify the targeting relationship between circ_0119872 and miR-582-3p as well as that between miR-582-3p and E2F3.

RESULTS

Circ_0119872 was remarkably upregulated in MM tissues and cell lines. Circ_0119872 knockdown suppressed the cell proliferation and metastasis In addition, miR-582-3p was identified as a downstream target of circ_0119872. The target genes of miR-193a-3p are involved in melanogenesis and cancer-related signaling pathways. Mechanistically, circ_0119872 facilitated MM progression by adsorbing miR-582-3p and upregulating E2F3 expression.

CONCLUSION

Circ_0119872 is an oncogenic circRNA that participates in the promotion of MM progression by regulating the miR-582-3p/E2F3 axis.

The microRNA cluster miR-214/miR-3120 prevents tumor cell switching from an epithelial to a mesenchymal-like phenotype and inhibits autophagy in gallbladder cancer

Tumor cells switch from an epithelial to a mesenchymal-like phenotype, which represents a key hallmark of human cancer metastasis, including gallbladder cancer (GBC). A large set of microRNAs (miRNAs/miRs) have been studied to elucidate their functions in initiating or inhibiting this phenotypic switching in GBC cells. In this paper, we attempted to identify the expression pattern of the miR-214/-3120 cluster and its mode of action in the context of GBC, with a specific focus being placed on their effects on EMT and autophagy in GBC cells. Human GBC cells GBC-SD were assayed for their migration, invasion, and autophagy using the Transwell chamber system, MDC staining, and transmission electron microscopy. The tumorigenicity and metastatic behavior of GBC-SD cells were tested in nude mice. The expression of EMT- and autophagy-specific markers (E-cadherin, N-cadherin, vimentin, ATG5, LC3II/LC3I, and Beclin1) was analyzed in cultured GBC-SD cells and in human GBC-SD xenografts. The E2F3 luciferase reporter activity in the presence of miR-214/-3120 was evaluated by a dual luciferase assay. The miR-214/-3120 was downregulated in GBC. Exogenous miR-214/-3120 inhibited the phenotypic switching of GBC cells from epithelial to mesenchymal, prevented autophagy, and suppressed the tumorigenicity and metastatic behavior of GBC-SD cells in vitro and in vivo. E2F3 was demonstrated to be the target gene of miR-214/-3120, and its knockdown in part mimicked the effect of miR-214/-3120 on the EMT, autophagy, tumorigenicity, and metastatic behavior of GBC-SD cells. These results demonstrated that the miR-214/-3120 cluster blocks the process of EMT and autophagy to limit GBC metastasis by repressing E2F3 expression.

miR-378a-5p and miR-630 induce lens epithelial cell apoptosis in cataract via suppression of E2F3

Cataract, an eye disease that threatens the health of millions of people, brings about severe economic burden for patients and society. MicroRNA (miR)-378a-5p and miR-630 were recognized as essential regulators in multiple cancers. However, the exact functions of miR-378a-5p and miR-630 in cataract are still unclear. The expression of miR-378a-5p, miR-630, and E2F transcription factor 3 (E2F3) in tissues and cells was measured by quantitative real-time polymerase chain reaction. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay was used to evaluate cell viability. Flow cytometry was conducted to analyze cell apoptosis. The interaction between E2F3 and miR-378a-5p or miR-630 was confirmed by dual-luciferase reporter assay. The expression of proteins E2F3, B cell lymphoma (Bcl-2), Bcl-2 associated X (Bax), and cleaved caspase 3 was detected by western blot assay. The expression of miR-378a-5p and miR-630 was up-regulated whereas E2F3 was down-regulated in human cataract lens tissues compared with normal lens tissues. Depletion of miR-378a-5p or miR-630 enhanced proliferation and reduced apoptosis of human lens epithelial cells. Interestingly, up-regulation of E2F3 exhibited the same trend. Next, dual-luciferase reporter assay validated the interaction between E2F3 and miR-378a-5p or miR-630. The rescue experiments further revealed that E2F3 knockdown could recover miR-378a-5p, and miR-630 inhibitor induced promotion of cell proliferation and inhibition of apoptosis in cataract. miR-378a-5p and miR-630 repressed proliferation and induced apoptosis of lens epithelial cells by targeting E2F3 in cataract, representing a prospective alternative therapy for cataract.

Identification of Key Biomarkers in Bladder Cancer: Evidence from a Bioinformatics Analysis

Bladder cancer (BCa) is one of the most common malignancies and has a relatively poor outcome worldwide. However, the molecular mechanisms and processes of BCa development and progression remain poorly understood. Therefore, the present study aimed to identify candidate genes in the carcinogenesis and progression of BCa. Five GEO datasets and TCGA-BLCA datasets were analyzed by statistical software R, FUNRICH, Cytoscape, and online instruments to identify differentially expressed genes (DEGs), to construct protein‒protein interaction networks (PPIs) and perform functional enrichment analysis and survival analyses. In total, we found 418 DEGs. We found 14 hub genes, and gene ontology (GO) analysis revealed DEG enrichment in networks and pathways related to cell cycle and proliferation, but also in cell movement, receptor signaling, and viral carcinogenesis. Compared with noncancerous tissues, TPM1, CRYAB, and CASQ2 were significantly downregulated in BCa, and the other hub genes were significant upregulated. Furthermore, MAD2L1 and CASQ2 potentially play a pivotal role in lymph nodal metastasis. CRYAB and CASQ2 were both significantly correlated with overall survival (OS) and disease-free survival (DFS). The present study highlights an up to now unrecognized possible role of CASQ2 in cancer (BCa). Furthermore, CRYAB has never been described in BCa, but our study suggests that it may also be a candidate biomarker in BCa.

MicroRNA‑433 reduces cell proliferation and invasion in non‑small cell lung cancer via directly targeting E2F transcription factor 3

MicroRNAs (miRNA/miRs) have been associated with the initiation and progression of non‑small‑cell lung cancer (NSCLC). Hence, a comprehensive understanding of the association between dysregulated miRNAs and NSCLC may contribute to the identification of novel therapeutic methods for patients with NSCLC. MiRNA‑433 (miR‑433) has been reported to be dysregulated in numerous types of human cancers; however, its expression pattern, biological roles and associated mechanisms in NSCLC require further investigation. The present study aimed to detect miR‑433 expression and determine its roles and underlying molecular mechanisms in NSCLC. In the present study, reverse transcription‑quantitative polymerase chain reaction revealed that miR‑433 was significantly downregulated in NSCLC tissues and cell lines. This decreased miR‑433 expression was strongly associated with the tumor node metastasis stage and lymph node metastasis of patients with NSCLC. Cell Counting kit‑8 and cell invasion assays revealed that the resumption of miR‑433 expression decreased the proliferation and invasion of NSCLC cells. Bioinformatics analysis predicted E2F transcription factor 3 (E2F3) as a potential target of miR‑433. Luciferase reporter assay, RT‑qPCR and western blot analysis further demonstrated that E2F3 was a direct target of miR‑433 in NSCLC. E2F3 downregulation induced by small interfering RNA exhibited inhibitory effects similar to those of miR‑433 overexpression in NSCLC cells, and the restored E2F3 expression counteracted the suppressive effects on NSCLC cells induced by miR‑433 overexpression. Therefore, miR‑433 may inhibit the progression of NSCLC, at least in part, by targeting E2F3. The present study indicated that miR‑433 may be investigated as an innovative candidate target for the therapy of patients with this fatal disease.

High expression of TMEM40 is associated with the malignant behavior and tumorigenesis in bladder cancer

BACKGROUND

Bladder cancer (BCa) is one of the most common cancers in the urinary system among the world. Previous studies suggested that TMEM40 expression level was significantly associated with clinicopathological parameters including histological grade, clinical stage and pT status of bladder cancer. However, the molecular mechanism of TMEM40 in BCa remains poorly understood.

METHODS

Real-time quantitative RT-PCR (qRT-PCR) and western blot (WB) were used to examine the expression levels of TMEM40 in BCa tissues, paired non-cancer tissues and cell lines. A series of experiments, including CCK-8, wound healing, flow cytometry, transwell and EdU assays were performed to assess the effects of TMEM40 on cell proliferation, cell cycle and apoptosis, migration and invasion. In addition, tumor growth was evaluated in vivo using a xenogenous subcutaneously implant model. All statistical analyses were executed by using the SPSS 20.0 software. All experimental data from three independent experiments were analyzed by Student's t test and results were expressed as mean ± standard deviation.

RESULTS

In this study, we identified the role of TMEM40 in the tumorigenesis of bladder cancer and found that it was upregulated in bladder cancer tissues and cell lines, compared with their normal counterparts. The results demonstrated that effective silence of TMEM40 expression suppressed cell proliferation, blocked G1-to-S cell cycle transition, and inhibited cell migration and invasion in human bladder 5637 and EJ cell lines. Consistently, in vivo data showed that TMEM40 silencing could dramatically decreased tumor growth. Further study revealed that TMEM40 knockdown resulted in accumulation of p53 and p21 protein and decrease of c-MYC and cyclin D1 protein.

CONCLUSION

These data suggest that TMEM40 represents a potential oncogene, which exert a crucial role in the proliferation and apoptosis via the p53 signaling pathway in BCa, thus probably serve as a novel candidate biomarker and a potential therapeutic target for patients with BCa.

MicroRNA-152 Suppresses Human Osteosarcoma Cell Proliferation and Invasion by Targeting E2F Transcription Factor 3

MicroRNA-152 (miR-152) expression has been reported to be downregulated in osteosarcoma (OS). However, the role of miR-152 in OS is not well documented. In the present study, we aimed to explore the function and underlying mechanism of miR-152 in OS. We found that miR-152 was underexpressed in OS tissues and cell lines. Decreased miR-152 was inversely correlated with lymph node metastasis and advanced clinical stage. Overexpression of miR-152 significantly inhibited cell proliferation, colony formation, migration, and invasion of OS cells. Bioinformatics analyses showed that miR-152 directly targeted E2F transcription factor 3 (E2F3), as further confirmed by a dual-luciferase reporter assay. E2F3 expression was upregulated and inversely correlated with miR-152 expression level in human OS tissues. Moreover, the inhibitory effects of miR-152 on OS growth and invasion were attenuated by E2F3 overexpression. Taken together, our findings indicated that miR-152 reduced OS growth and invasion by targeting E2F3 and provided new evidence of miR-152 as a potential therapeutic target for OS.

Clinical value of miR-425-5p detection and its association with cell proliferation and apoptosis of gastric cancer

Researches have shown that miR-425-5p expression altered in lung, esophageal, and glial cancer. Similarly, in our previous study, we found miR-425-5p expression was up-regulated in GC cells and could promote gastric cancer (GC) cell invasion and metastasis. However, the functional mechanism and the prognostic significance of miR-425-5p in GC remain unclear. Therefore, the present study examined miR-425-5p expression in GC tissues and also evaluated miR-425-5p of the therapeutic and prognostic value. Moreover, with interference of miR-425-5p expression in cell lines, we investigated the molecular mechanism of miR-425-5p and the expression level was higher in GC tissues comparing with that in gastric tumor-adjacent mucosa. These results suggested that miR-425-5p over-expression may be associated with depth of invasion and TNM stages and can be a prognostic marker of poor outcome. After inhibition of miR-425-5p expression in MKN45 cells, the cell activity was weakened. The number of G0/G1 cells increased while G2/M and S cells decreased, and the cell apoptotic rates elevated (P<0.05). Some proliferation and apoptosis related genes were altered (P<0.05). Consequently, miR-425-5p can be considered as a marker of poor prognosis and it is probably involved in GC cell proliferation and apoptosis by regulating some of the genes which participate these processes.