DANCR Promotes Metastasis and Proliferation in Bladder Cancer Cells by Enhancing IL-11-STAT3 Signaling and CCND1 Expression

Interplay between JAK/STAT pathway and non-coding RNAs in different cancers

Progress in the identification of core multi-protein modules within JAK/STAT pathway has enabled researchers to develop a better understanding of the linchpin role of deregulated signaling cascade in carcinogenesis and metastasis. More excitingly, complex interplay between JAK/STAT pathway and non-coding RNAs has been shown to reprogramme the outcome of signaling cascade and modulate immunological responses within tumor microenvironment. Wealth of information has comprehensively illustrated that most of this complexity regulates the re-shaping of the immunological responses. Increasingly sophisticated mechanistic insights have illuminated fundamental role of STAT-signaling in polarization of macrophages to M2 phenotype that promotes disease aggressiveness. Overall, JAK/STAT signaling drives different stages of cancer ranging from cancer metastasis to the reshaping of the tumor microenvironment. JAK/STAT signaling has also been found to play role in the regulation of infiltration and activity of natural killer cells and CD4/CD8 cells by PD-L1/PD-1 signaling. In this review, we have attempted to set spotlight on regulation of JAK/STAT pathway by microRNAs, long non-coding RNAs and circular RNAs in primary tumors and metastasizing tumors. Therefore, existing knowledge gaps need to be addressed to propel this fledgling field of research to the forefront and bring lncRNAs and circRNAs to the frontline of clinical practice. Leveraging the growing momentum will enable interdisciplinary researchers to gain transition from segmented view to a fairly detailed conceptual continuum.

Oncogenic SLC2A11-MIF fusion protein interacts with polypyrimidine tract binding protein 1 to facilitate bladder cancer proliferation and metastasis by regulating mRNA stability

Chimeric RNAs, distinct from DNA gene fusions, have emerged as promising therapeutic targets with diverse functions in cancer treatment. However, the functional significance and therapeutic potential of most chimeric RNAs remain unclear. Here we identify a novel fusion transcript of solute carrier family 2-member 11 (SLC2A11) and macrophage migration inhibitory factor (MIF). In this study, we investigated the upregulation of SLC2A11-MIF in The Cancer Genome Atlas cohort and a cohort of patients from Sun Yat-Sen Memorial Hospital. Subsequently, functional investigations demonstrated that SLC2A11-MIF enhanced the proliferation, antiapoptotic effects, and metastasis of bladder cancer cells in vitro and in vivo. Mechanistically, the fusion protein encoded by SLC2A11-MIF interacted with polypyrimidine tract binding protein 1 (PTBP1) and regulated the mRNA half-lives of Polo Like Kinase 1, Roundabout guidance receptor 1, and phosphoinositide-3-kinase regulatory subunit 3 in BCa cells. Moreover, PTBP1 knockdown abolished the enhanced impact of SLC2A11-MIF on biological function and mRNA stability. Furthermore, the expression of SLC2A11-MIF mRNA is regulated by CCCTC-binding factor and stabilized through RNA N4-acetylcytidine modification facilitated by N-acetyltransferase 10. Overall, our findings revealed a significant fusion protein orchestrated by the SLC2A11-MIF-PTBP1 axis that governs mRNA stability during the multistep progression of bladder cancer.

SUMO E3 ligase MUL1 inhibits lymph node metastasis of bladder cancer by mediating mitochondrial HSPA9 translocation

Lymph node (LN) metastasis is the dominant cause of death in bladder cancer (BCa) patients, but the underlying mechanism remains largely unknown. In recent years, accumulating studies have confirmed that bidirectional mitochondria-nucleus communication is essential for sustaining multiple function of mitochondria. However, little has been studied regarding whether and how the translocation of mitochondrial proteins is involved in LN metastasis. In this study, we first identified that the SUMO E3 ligase MUL1 was significantly downregulated in LN-metastatic BCa tissues and correlated with a good prognosis. Mechanistically, MUL1 SUMOylated HSPA9 at the K612 residue, leading to HSPA9 export from mitochondria and interaction with SUZ12 and in the nucleus. Consequently, MUL1 induced the ubiquitination-mediated degradation of SUZ12 and EZH2 and induced downstream STAT3 pathway inhibition in a HSPA9-dependent manner. Importantly, mutation of HSPA9 SUMO-conjugation motifs limited the translocation of mitochondrial HSPA9 and blocked the HSPA9-SUZ12 and HSPA9-EZH2 interactions. With mutation of the HSPA9 K612 site, the suppressive role of MUL1 overexpression was lost in BCa cells. Further in vitro and in vivo assays revealed that MUL1 inhibits the metastasis and proliferation of BCa cells. Overall, our study reveals a novel function and molecular mechanism of SUMO E3 ligases in LN metastasis.

New evidence for a role of DANCR in cancers: a comprehensive review

Cancer remains a leading cause of mortality and poses a substantial threat to public health. Studies have revealed that Long noncoding RNA DANCR is a cytoplasmic lncRNA whose aberrant expression plays a pivotal role in various cancer types. Within tumour biology, DANCR exerts regulatory control over crucial processes such as proliferation, invasion, metastasis, angiogenesis, inflammatory responses, cellular energy metabolism reprogramming, and apoptosis. By acting as a competitive endogenous RNA for miRNAs and by interacting with proteins and mRNAs at the molecular level, DANCR contributes significantly to cancer progression. Elevated DANCR levels have also been linked to heightened resistance to anticancer drugs. Moreover, the detection of circulating DANCR holds promise as a valuable biomarker for aiding in the clinical differentiation of different cancer types. This article offers a comprehensive review and elucidation of the primary functions and molecular mechanisms through which DANCR influences tumours.

Comprehensive pan-cancer analysis identifies the RNA-binding protein LRPPRC as a novel prognostic and immune biomarker

AIMS

RNA-binding proteins (RBPs) play pivotal roles in carcinogenesis and immunotherapy. Leucine-rich pentapeptide repeat-containing protein (LRPPRC) is crucial for RNA polyadenylation, transport, and stability. Although recent studies have suggested LRPPRC's potential role in tumor progression, its significance in tumor prognosis, diagnosis, and immunology remains unclear.

MAIN METHODS

We comprehensively analyzed LRPPRC expression in tumors using various databases, including Human Transcriptome Cell Atlas (HTCA), University of California Santa Cruz (UCSC), Human Protein Atlas (HPA), Sangerbox, TISIDB, GeneMANIA, GSCALite, and CellMiner. We examined the correlation between LRPPRC expression level and prognosis, immune infiltration, immunotherapy, methylation, biological function, and drug sensitivity. Single-cell analysis was performed using Tumor Immune Single Cell Hub (TISCH) and CancerSEA software. Patients with acute myeloid leukemia (AML) were categorized based on LRPPRC levels for functional and immune infiltration analyses. The role of LRPPRC in cancer was validated using in vitro experiments.

KEY FINDINGS

Our findings revealed that LRPPRC was highly expressed in almost all cancer types, indicating its significant prognostic and diagnostic potential. Notably, LRPPRC was associated with diverse immune features, such as immune cell infiltration, immune checkpoint genes, tumor mutational burden, and microsatellite instability, suggesting its value in guiding immunotherapy strategies. Within AML, the high-expression group had lower levels of immune cells, including CD8+ T cells. In vitro experiments confirmed the inhibitory effects of LRPPRC knockdown on AML cell proliferation.

SIGNIFICANCE

This study highlights LRPPRC as a reliable pan-cancer prognostic and immune biomarker, particularly in AML. It lays the groundwork for future research on LRPPRC-targeted cancer therapies.

Targeting IL-6/STAT3 signaling abrogates EGFR-TKI resistance through inhibiting Beclin-1 dependent autophagy in HNSCC

Head and neck squamous cell carcinoma (HNSCC) is featured by notorious EGFR tyrosine kinase inhibitor (TKI) resistance attributable to activation of parallel pathways. The numerous phase I/II trials have rarely shown encouraging clinical outcomes of EGFR-TKIs during treatment in HNSCC patients with advanced tumors. A unique IL-6/STAT3 signaling axis is reported to regulate multiple cancer-related pathways, but whether this signaling is correlated with reduced EGFR-TKI responsiveness is unclear. Here, we found that STAT3 signaling is compensatorily upregulated after EGFR-TKI exposure and confers anti-EGFR therapy resistance during HNSCC therapy. Targeting STAT3 using small molecule inhibitors promotes complete recovery or sustained elimination of HNSCC tumors through combination with EGFR-TKIs both in vitro and in diverse animal models. Mechanistically, phosphorylated STAT3 was proven to enhance oncogenic autophagic flux, protecting cancer cells and preventing EGFR-TKI-induced tumor apoptosis. Thus, blockade of STAT3 signaling simultaneously disrupts several key interactions during tumor progression and remodels the autophagic degradation system, thereby rendering advanced HNSCC eradicable through combination with EGFR-TKI therapy. These findings provide a clinically actionable strategy and suggest STAT3 as a predictive biomarker with therapeutic potential for EGFR-TKI resistant HNSCC patients.

Design, synthesis, and biological evaluation of naphthoylamide derivatives as inhibitors of STAT3 phosphorylation

The phosphorylation of STAT3 plays a critical physiological role in the proliferation of rectal cancer. Hence, inhibiting STAT3 phosphorylation is an effective anticancer approach. In this work, we designed a novel 5-R'-1-naphthylmethylamide scaffold as a small molecule inhibitor of STAT3 phosphorylation. The results showed that 3D and 4D have exceptional inhibitory ability against three different colorectal cancer (CRC) cell lines, and can induce apoptosis of CRC cells by inhibiting STAT3 phosphorylation, while having no killing effect on normal human cells. 3D and 4D can inhibit STAT3 phosphorylation in a time- and concentration-dependent manner, and also inhibit the nuclear translocation of interleukin (IL)-6-induced STAT3. In the in vivo tumor model research, 4D significantly reduced the tumor volume of mice and had no drug toxicity on other organ tissues. Furthermore, molecular docking studies revealed that 3D and 4D had greater binding free energy when interacting with the STAT3 SH2 structural domain, and could establish H-π interaction modes. Dynamic simulation studies indicated that both compounds were able to bind tightly to STAT3.

Establishment of a prognostic model to predict chemotherapy response and identification of RAC3 as a chemotherapeutic target in bladder cancer

Cisplatin-based chemotherapy is considered the primary treatment option for patients with advanced bladder cancer (BCa). However, the objective response rate to chemotherapy is often unsatisfactory, leading to a poor 5-year survival rate. Furthermore, current strategies for evaluating chemotherapy response and prognosis are limited and inefficient. In this study, we aimed to address these challenges by establishing a chemotherapy response type gene (CRTG) signature consisting of 9 genes and verified the prognostic value of this signature using TCGA and GEO BCa cohorts. The risk scores based on the CRTG signature were found to be associated with advanced clinicopathological status and demonstrated favorable predictive power for chemotherapy response in the TCGA cohort. Meanwhile, tumors with high risk scores exhibited a tendency toward a "cold tumor" phenotype. These tumors showed a low abundance of T cells, CD8+ T cells and cytotoxic lymphocytes, along with a high abundance of cancer-associated fibroblasts. Moreover, they displayed higher mRNA levels of these immune checkpoints: CD200, CD276, CD44, NRP1, PDCD1LG2 (PD-L2), and TNFSF9. Furthermore, we developed a nomogram that integrated the CRTG signature with clinicopathologic risk factors. This nomogram proved to be a more effective tool for predicting the prognosis of BCa patients. Additionally, we identified Rac family small GTPase 3 (RAC3) as a biomarker in our model. RAC3 was found to be overexpressed in chemoresistant BCa tissues and enhance the chemotherapeutic resistance of BCa cells in vitro and in vivo by regulating the PAK1-ERK1/2 pathway. In conclusion, our study presents a novel CRTG model for predicting chemotherapy response and prognosis in BCa. We also highlight the potential of combining chemotherapy with immunotherapy as a promising strategy for chemoresistant BCa and that RAC3 might be a latent target for therapeutic intervention.

LRPPRC promotes glycolysis by stabilising LDHA mRNA and its knockdown plus glutamine inhibitor induces synthetic lethality via m6 A modification in triple-negative breast cancer

BACKGROUND

Targeted therapy for triple-negative breast cancer (TNBC) remains a challenge. N6-methyladenosine (m6 A) is the most abundant internal mRNA modification in eukaryotes, and it regulates the homeostasis and function of modified RNA transcripts in cancer. However, the role of leucine-rich pentatricopeptide repeat containing protein (LRPPRC) as an m6 A reader in TNBC remains poorly understood.

METHODS

Western blotting, reverse transcription-polymerase chain reaction (RT-qPCR) and immunohistochemistry were used to investigate LRPPRC expression levels. Dot blotting and colorimetric enzyme linked immunosorbent assay (ELISA) were employed to detect m6 A levels. In vitro functional assays and in vivo xenograft mouse model were utilised to examine the role of LRPPRC in TNBC progression. Liquid chromatography-mass spectrometry/mass spectrometry and Seahorse assays were conducted to verify the effect of LRPPRC on glycolysis. MeRIP-sequencing, RNA-sequencing, MeRIP assays, RNA immunoprecipitation assays, RNA pull-down assays and RNA stability assays were used to identify the target genes of LRPPRC. Patient-derived xenografts and organoids were employed to substantiate the synthetic lethality induced by LRPPRC knockdown plus glutaminase inhibition.

RESULTS

The expressions of LRPPRC and m6 A RNA were elevated in TNBC, and the m6 A modification site could be recognised by LRPPRC. LRPPRC promoted the proliferation, metastasis and glycolysis of TNBC cells both in vivo and in vitro. We identified lactate dehydrogenase A (LDHA) as a novel direct target of LRPPRC, which recognised the m6 A site of LDHA mRNA and enhanced the stability of LDHA mRNA to promote glycolysis. Furthermore, while LRPPRC knockdown reduced glycolysis, glutaminolysis was enhanced. Moreover, the effect of LRPPRC on WD40 repeat domain-containing protein 76 (WDR76) mRNA stability was impaired in an m6 A-dependent manner. Then, LRPPRC knockdown plus a glutaminase inhibition led to synthetic lethality.

CONCLUSIONS

Our study demonstrated that LRPPRC promoted TNBC progression by regulating metabolic reprogramming via m6 A modification. These characteristics shed light on the novel combination targeted therapy strategies to combat TNBC.

Therapeutic Effects of Berberine against Urological Cancers: Biological Potentials Based on Cellular Mechanisms

BACKGROUND

Urological cancers, encompassing prostate, kidney, and bladder cancers, pose significant global health challenges. Current treatment modalities, including chemotherapy, radiotherapy, and surgery, individually or in combination, have limitations in efficacy and are associated with notable morbidity and mortality.

METHODS

This review explores alternative therapeutic avenues, emphasizing the exploration of natural compounds, with a specific focus on berberine. Berberine's potential as a treatment for urological cancers is investigated through an extensive examination of cellular and molecular mechanisms.

RESULTS

The comprehensive analysis reveals promising anticancer properties associated with berberine, substantiated by a wealth of experimental studies. The agent's impact on urological cancers is discussed, highlighting notable findings related to its efficacy and safety profile.

CONCLUSIONS

Given the high mortality rates and potential side effects associated with current standard treatments for urological cancers, the exploration of alternative, effective, and safer options is imperative. This review underscores berberine's therapeutic potential, shedding light on its anticancer effects and encouraging further research in the pursuit of enhanced treatment strategies.

SYNPO2 promotes the development of BLCA by upregulating the infiltration of resting mast cells and increasing the resistance to immunotherapy

Synaptopodin 2 (SYNPO2) plays a pivotal role in regulating tumor growth, development and progression in bladder urothelial Carcinoma (BLCA). However, the precise biological functions and mechanisms of SYNPO2 in BLCA remain unclear. Based on TCGA database‑derived BLCA RNA sequencing data, survival analysis and prognosis analysis indicate that elevated SYNPO2 expression was associated with poor survival outcomes. Notably, exogenous SYNPO2 expression significantly promoted tumor invasion and migration by upregulating vimentin expression in BLCA cell lines. Enrichment analysis revealed the involvement of SYNPO2 in humoral immune responses and the PI3K/AKT signaling pathway. Moreover, increased SYNPO2 levels increased the sensitivity of BLCA to PI3K/AKT pathway‑targeted drugs while being resistant to conventional chemotherapy. In in vivo BLCA mouse models, SYNPO2 overexpression increased pulmonary metastasis of 5637 cells. High SYNPO2 expression led to increased infiltration of innate immune cells, particularly mast cells, in both nude mouse model and clinical BLCA samples. Furthermore, tumor immune dysfunction and exclusion score showed that patients with BLCA patients and high SYNPO2 expression exhibited worse clinical outcomes when treated with immune checkpoint inhibitors. Notably, in the IMvigor 210 cohort, SYNPO2 expression was significantly associated with the population of resting mast cells in BLCA tissue following PD1/PDL1 targeted therapy. In conclusion, SYNPO2 may be a promising prognostic factor in BLCA by modulating mast cell infiltration and exacerbating resistance to immune therapy and conventional chemotherapy.

A HER2-targeted Antibody-Drug Conjugate, RC48-ADC, Exerted Promising Antitumor Efficacy and Safety with Intravesical Instillation in Preclinical Models of Bladder Cancer

More than half of non-muscle-invasive bladder cancer (NMIBC) patients eventually relapse even if treated with surgery and BCG without optional bladder-preserving therapy. This study aims to investigate the antitumor activity and safety of a HER2-targeted antibody-drug conjugate, RC48-ADC, intravesical instillation for NMIBC treatment. In this preclinical study, it is revealed that human epidermal growth factor receptor 2 (HER2) expression scores of 1+, 2+, and 3+ are recorded for 16.7%, 56.2%, and 14.6% of NMIBC cases. The antitumor effect of RC48-ADC is positively correlated with HER2 expression in bladder cancer (BCa) cell lines and organoid models. Furthermore, RC48-ADC is revealed to exert its antitumor effect by inducing G2/M arrest and caspase-dependent apoptosis. In an orthotopic BCa model, tumor growth is significantly inhibited by intravesical instillation of RC48-ADC versus disitamab, monomethyl auristatin E, epirubicin, or phosphate-buffered saline control. The potential toxicity of intravesical RC48-ADC is also assessed by dose escalation in normal nude mice and revealed that administration of RC48-ADC by intravesical instillation is safe within the range of effective therapeutic doses. Taken together, RC48-ADC demonstrates promising antitumor effects and safety with intravesical administration in multiple preclinical models. These findings provide a rational for clinical trials of intravesical RC48-ADC in NMIBC patients.

LRPPRC regulates malignant behaviors, protects mitochondrial homeostasis, mitochondrial function in osteosarcoma and derived cancer stem-like cells

BACKGROUND

Leucine-rich pentatricopeptide repeat containing (LRPPRC) is a potential oncogene in multiple tumor types, including lung adenocarcinoma, esophageal squamous cell carcinoma and gastric cancer. LRPPRC exerts its tumor-promoting effects mainly by regulating mitochondrial homeostasis and inducing oxidative stress. However, the exact role and mechanisms by which LRPPRC acts in osteosarcoma and osteosarcoma-derived cancer stem-like cells (CSCs), which potentially critically contribute to recurrence, metastasis and chemoresistance, are still largely unclear.

METHODS

LRPPRC level in osteosarcoma cells and CSCs were detected by western blot. Effects of LRPPRC on CSCs were accessed after LRPPRC knockdown by introducing lentivirus containing shRNA targeting to LRPPRC mRNA.

RESULTS

we found that LRPPRC was highly expressed in several osteosarcoma cell lines and that LRPPRC knockdown inhibited malignant behaviors, including proliferation, invasion, colony formation and tumor formation, in MG63 and U2OS cells. Enriched CSCs derived from MG63 and U2OS cells presented upregulated LRPPRC levels compared to parental cells (PCs), and LRPPRC knockdown markedly decreased the sphere-forming capacity. These findings demonstrate that LRPPRC knockdown decreased stemness in CSCs. Consistent with a previous report, LRPPRC knockdown decreased the expression levels of FOXM1 and its downstream target genes, including PRDX3, MnSOD and catalase, which are responsible for scavenging reactive oxygen species (ROS). Expectedly, LRPPRC knockdown increased the accumulation of ROS in osteosarcoma and osteosarcoma-derived CSCs under hypoxic conditions due to the decrease in ROS scavenging proteins. Moreover, LRPPRC knockdown sensitized osteosarcomas and CSCs against carboplatin, a ROS-inducing chemoagent, and promoted apoptosis. Furthermore, LRPPRC knockdown significantly decreased the mitochondrial membrane potential, disturbed mitochondrial homeostasis and led to mitochondrial dysfunction.

CONCLUSION

Taken together, these findings indicated that LRPPRC exerts critical roles in regulating mitochondrial homeostasis, mitochondrial function and tumorigenesis in osteosarcomas and osteosarcoma-derived CSCs. This suggests that LRPPRC might be a promising therapeutic target for osteosarcomas.

LncRNA MIR4435-2HG drives cancer progression by modulating cell cycle regulators and mTOR signaling in stroma-enriched subtypes of urothelial carcinoma of the bladder

BACKGROUND

The risk for recurrence and metastasis after treatment for urothelial carcinoma of the bladder (UCB) is high. Therefore, identifying efficient prognostic markers and novel therapeutic targets is urgently needed. Several long noncoding RNAs (lncRNAs) have been reported to be correlated with UCB progression. In this study, we found that the subtype-specific lncRNA MIR4435-2 host gene (MIR4435-2HG) plays a novel oncogenic role in UCB.

METHODS

RNA-Seq data of TCGA/BLCA were analyzed. The expression of MIR4435-2HG was measured by qRT-PCR in 16 pairs of bladder cancer tissues and adjacent normal tissues. The clinical relecance of MIR4435-2HG was validated via in situ hybridization performed on an in-house cohort of 116 UCB patient samples. RNA pull-down followed by mass spectrometry was performed to identify MIR4435-2HG-binding proteins. To identify signaling pathways involved in MIR4435-2HG activity, comprehensive in vitro and in vivo studies and RNA-Seq assays were performed using UCB cells in which MIR4435-2HG expression was knocked down or exogenously overexpressed. In addition, we performed RNA immunoprecipitation and Western blot analyses to validate the identified MIR4435-2HG-binding proteins and to determine the molecular mechanisms by which MIR4435-2HG promotes UCB progression.

RESULTS

We found that MIR4435-2HG was significantly upregulated in the stromal-enriched subtype of UCB. Increased MIR4435-2HG expression was positively correlated with a high histological grade, advanced T stages, larger tumors, lymph node metastasis and a poor prognosis. In vitro experiments revealed that MIR4435-2HG expression silencing suppressed cell proliferation and induced apoptosis. Inhibition of MIR4434-2HG delayed xenograft tumor growth, while MIR4435-2HG overexpression reversed the MIR4435-2HG silencing-induced inhibition of UCB tumor phenotype acquisition. Mechanistically, we found that MIR4435-2HG positively regulated the expression of a variety of cell cycle regulators, including BRCA2 and CCND1. Knocking down MIR4435-2HG increased the sensitivity of tumor cells to the VEGFR inhibitor cediranib. Furthermore, we found that MIR4435-2HG regulated mTOR signaling and epithelial-mesenchymal transition (EMT) signaling pathways by modulating the phosphorylation of mTOR, 70S6K and 4EBP1. Finally, we confirmed that MIR4435-2HG enhances tumor metastasis through regulation of the EMT pathway.

CONCLUSIONS

Our data indicate that upregulated MIR4435-2HG expression levels are significantly correlated with a poor prognosis of UCB patients. MIR4435-2HG promotes bladder cancer progression, mediates cell cycle (de)regulation and modulates mTOR signaling. MIR4435-2HG is an oncogenic lncRNA in UCB that may serve as a diagnostic and therapeutic target.

The RNA-binding protein LRPPRC promotes resistance to CDK4/6 inhibition in lung cancer

Kinase inhibitors against Cyclin Dependent Kinase 4 and 6 (CDK4/6i) are promising cancer therapeutic drugs. However, their effects are limited by primary or acquired resistance in virtually all tumor types. Here, we demonstrate that Leucine Rich Pentatricopeptide Repeat Containing (LRPPRC) controls CDK4/6i response in lung cancer by forming a feedback loop with CDK6. LRPPRC binds to CDK6-mRNA, increasing the stability and expression of CDK6. CDK6 and its downstream E2F Transcription Factor 1 (E2F1), bind to the LRPPRC promoter and elevate LRPPRC transcription. The activation of the LRPPRC-CDK6 loop facilitates cell cycle G1/S transition, oxidative phosphorylation, and cancer stem cell generation. Gossypol acetate (GAA), a gynecological medicine that has been repurposed as a degrader of LRPPRC, enhances the CDK4/6i sensitivity in vitro and in vivo. Our study reveals a mechanism responsible for CDK4/6i resistance and provides an enlightening approach to investigating the combinations of CDK4/6 and LRPPRC inhibitors in cancer therapy.

UBE2S interacting with TRIM21 mediates the K11-linked ubiquitination of LPP to promote the lymphatic metastasis of bladder cancer

Lymphatic metastasis is the most common pattern of bladder cancer (BCa) metastasis and has an extremely poor prognosis. Emerging evidence shows that ubiquitination plays crucial roles in various processes of tumors, including tumorigenesis and progression. However, the molecular mechanisms underlying the roles of ubiquitination in the lymphatic metastasis of BCa are largely unknown. In the present study, through bioinformatics analysis and validation in tissue samples, we found that the ubiquitin-conjugating E2 enzyme UBE2S was positively correlated with the lymphatic metastasis status, high tumor stage, histological grade, and poor prognosis of BCa patients. Functional assays showed that UBE2S promoted BCa cell migration and invasion in vitro, as well as lymphatic metastasis in vivo. Mechanistically, UBE2S interacted with tripartite motif containing 21 (TRIM21) and jointly induced the ubiquitination of lipoma preferred partner (LPP) via K11-linked polyubiquitination but not K48- or K63-linked polyubiquitination. Moreover, LPP silencing rescued the anti-metastatic phenotypes and inhibited the epithelial-mesenchymal transition of BCa cells after UBE2S knockdown. Finally, targeting UBE2S with cephalomannine distinctly inhibited the progression of BCa in cell lines and human BCa-derived organoids in vitro, as well as in a lymphatic metastasis model in vivo, without significant toxicity. In conclusion, our study reveals that UBE2S, by interacting with TRIM21, degrades LPP through K11-linked ubiquitination to promote the lymphatic metastasis of BCa, suggesting that UBE2S represents a potent and promising therapeutic target for metastatic BCa.

Targeting cyclin D1 as a therapeutic approach for papillary thyroid carcinoma

Cyclin D1 functions as a mitogenic sensor that specifically binds to CDK4/6, thereby integrating external mitogenic inputs and cell cycle progression. Cyclin D1 interacts with transcription factors and regulates various important cellular processes, including differentiation, proliferation, apoptosis, and DNA repair. Therefore, its dysregulation contributes to carcinogenesis. Cyclin D1 is highly expressed in papillary thyroid carcinoma (PTC). However, the particular cellular mechanisms through which abnormal cyclin D1 expression causes PTC are poorly understood. Unveiling the regulatory mechanisms of cyclin D1 and its function in PTC may help determine clinically effective strategies, and open up better opportunities for further research, leading to the development of novel PTC regimens that are clinically effective. This review explores the mechanisms underlying cyclin D1 overexpression in PTC. Furthermore, we discuss the role of cyclin D1 in PTC tumorigenesis via its interactions with other regulatory elements. Finally, recent progress in the development of therapeutic options targeting cyclin D1 in PTC is examined and summarized.

ETV4 Mediated Tumor-Associated Neutrophil Infiltration Facilitates Lymphangiogenesis and Lymphatic Metastasis of Bladder Cancer

As a key step of tumor lymphatic metastasis, lymphangiogenesis is regulated by VEGFC-VEGFR3 signaling pathway mediated by immune cells, mainly macrophages, in the tumor microenvironment. However, little is known whether tumor associated neutrophils are involved in lymphangiogenesis. Here, it is found that TANs infiltration is increased in LN-metastatic BCa and is associated with poor prognosis. Neutrophil depletion results in significant reduction in popliteal LN metastasis and lymphangiogenesis. Mechanistically, transcription factor ETV4 enhances BCa cells-derived CXCL1/8 to recruit TANs, leading to the increase of VEGFA and MMP9 from TANs, and then facilitating lymphangiogenesis and LN metastasis of BCa. Moreover, phosphorylation of ETV4 at tyrosine 392 by tyrosine kinase PTK6 increases nuclear translocation of ETV4 and is essential for its function in BCa. Overall, the findings reveal a novel mechanism of how tumor cells regulate TANs-induced lymphangiogenesis and LN metastasis and identify ETV4 as a therapeutic target of LN metastasis in BCa.

Discovery of Transacting Long Noncoding RNAs That Regulate Smooth Muscle Cell Phenotype

BACKGROUND

Smooth muscle cells (SMC), the major cell type in atherosclerotic plaques, are vital in coronary artery diseases (CADs). SMC phenotypic transition, which leads to the formation of various cell types in atherosclerotic plaques, is regulated by a network of genetic and epigenetic mechanisms and governs the risk of disease. The involvement of long noncoding RNAs (lncRNAs) has been increasingly identified in cardiovascular disease. However, SMC lncRNAs have not been comprehensively characterized, and their regulatory role in SMC state transition remains unknown.

METHODS

A discovery pipeline was constructed and applied to deeply strand-specific RNA sequencing from perturbed human coronary artery SMC with different disease-related stimuli, to allow for the detection of novel lncRNAs. The functional relevance of a select few novel lncRNAs were verified in vitro.

RESULTS

We identified 4579 known and 13 655 de novo lncRNAs in human coronary artery SMC. Consistent with previous long noncoding RNA studies, these lncRNAs overall have fewer exons, are shorter in length than protein-coding genes (pcGenes), and have relatively low expression level. Genomic location of these long noncoding RNA is disproportionately enriched near CAD-related TFs (transcription factors), genetic loci, and gene regulators of SMC identity, suggesting the importance of their function in disease. Two de novo lncRNAs, ZIPPOR (ZEB-interacting suppressor) and TNS1-AS2 (TNS1-antisense 2), were identified by our screen. Combining transcriptional data and in silico modeling along with in vitro validation, we identified CAD gene ZEB2 as a target through which these lncRNAs exert their function in SMC phenotypic transition.

CONCLUSIONS

Expression of a large and diverse set of lncRNAs in human coronary artery SMC are highly dynamic in response to CAD-related stimuli. The dynamic changes in expression of these lncRNAs correspond to alterations in transcriptional programs that are relevant to CAD, suggesting a critical role for lncRNAs in SMC phenotypic transition and human atherosclerotic disease.

Cytoskeleton regulator RNA expression on cancer-associated fibroblasts is associated with prognosis and immunotherapy response in bladder cancer

Background

Dysregulation of long noncoding RNAs (lncRNAs) has been reported to be associated with multiple tumors where they act as tumor suppressors or accelerators. The lncRNA CYTOR was identified as an oncogene involved in many cancers, such as gastric cancer, colorectal cancer, hepatocellular carcinoma, and renal cell carcinoma. However, the role of CYTOR in bladder cancer (BCa) has rarely been reported.

Methods

Using cancer datasets from The Cancer Genome Atlas (TCGA) program, we analyzed the association between CYTOR expression and prognostic value, oncogenic pathways, antitumor immunity and immunotherapy response in BCa. The influence of CYTOR on the immune infiltration pattern in the urothelial carcinoma microenvironment was further verified in our dataset. Single-cell analysis revealed the role of CYTOR in the tumor microenvironment (TME) of BCa. Finally, we evaluated the expression of CYTOR in BCa in the Peking University First Hospital (PKU-BCa) dataset and its correlation with the malignant phenotype of BCa in vitro and in vivo.

Results

The results indicated that CYTOR was highly expressed in multiple cancer samples, including BCa, and increased CYTOR expression contributed to poor overall survival (OS). Additionally, elevated CYTOR expression was significantly correlated with clinicopathological features of BCa, such as female sex, advanced TNM stage, high histological grade and non-papillary subtype. Functional characterization revealed that CYTOR may be involved in immune-related pathways and the epithelial mesenchymal transformation (EMT) process. Moreover, CYTOR had a significant association with infiltrating immune cells, including M2 macrophages and regulatory T cells (Tregs). CYTOR facilitates the crosstalk between cancer-associated fibroblasts (CAFs) and macrophages, and mediates M2 polarization of macrophages. Correlation analysis revealed a positive correlation between CYTOR expression and programmed cell death-1 (PD-1)/programmed death ligand 1 (PD-L1)/expression and other targets for specific immunotherapy in BCa, which are recognized to predict the efficacy of immunotherapy.

Conclusions

These results suggest that CYTOR serves as a potential biomarker for predicting survival outcome, TME cell infiltration characteristics and immunotherapy response in BCa.

The Diagnostic and Therapeutic Role of snoRNA and lincRNA in Bladder Cancer

Bladder cancer is one of the most common malignancies of the urinary tract and can be divided into non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). Although the means of diagnosis and treatment have continually improved in recent years, the recurrence rate of bladder cancer remains high, and patients with MIBC typically have an unfavourable prognosis and a low quality of life. Emerging evidence demonstrates that long noncoding RNAs play a crucial role in the carcinogenesis and progression of bladder cancer. Long intergenic noncoding RNAs (lincRNAs) are a subgroup of long noncoding RNAs (lncRNAs) that do not overlap protein-coding genes. The potential role of lincRNAs in the regulation of gene expression has been explored in depth in recent years. Small nucleolar RNAs (snoRNAs) are a class of noncoding RNAs (ncRNAs) that mainly exist in the nucleolus, are approximately 60-300 nucleotides in length, and are hosted inside the introns of genes. Small nucleolar RNA host genes (SNHGs) have been associated with the origin and development of bladder cancer. In this review, we aim to comprehensively summarize the biological functions of these molecules in bladder cancer.

GPR84 potently inhibits osteoclastogenesis and alleviates osteolysis in bone metastasis of colorectal cancer

The expression of GPR84 in bone marrow-derived monocytes/macrophages (BMMs) can inhibit osteoclast formation; however, its role in bone metastasis of colorectal cancer (CRC) is still unknown. To investigate the effects of GPR84 on bone metastasis of CRC, the murine CRC cell line MC-38 was injected into tibial bone marrow. We found that the expression of GPR84 in BMMs was gradually downregulated during bone metastasis of CRC, and the activation of GPR84 significantly prevented osteoclastogenesis in the tumor microenvironment. Mechanistically, the MAPK pathway mediated the effects of GPR84 on osteoclast formation. Moreover, we found that IL-11 at least partly inhibited the expression of GPR84 in the tumor microenvironment through the inactivation of STAT1. Additionally, activation of GPR84 could prevent osteolysis during bone metastasis of CRC. Our results suggest that CRC cells downregulate the expression of GPR84 in BMMs to promote osteoclastogenesis in an IL-11-dependent manner. Thus, GPR84 could be a potential therapeutic target to attenuate bone destruction induced by CRC metastasis.

Hispolon Methyl Ether, a Hispolon Analog, Suppresses the SRC/STAT3/Survivin Signaling Axis to Induce Cytotoxicity in Human Urinary Bladder Transitional Carcinoma Cell Lines

Bladder cancer is a leading human malignancy worldwide. Signal transducer and activator of transcription (STAT) 3 is an oncogenic transcription factor commonly hyperactivated in most human cancers, including bladder cancer. Notably, preclinical evidence has validated STAT3 blockade as a promising therapeutic strategy for bladder cancer. Hispolon Methyl Ether (HME) is a structural analog of hispolon, an anticancer component of the medicinal mushroom Phellinus linteus. Thus far, HME's anticancer activity and mechanisms remain largely unknown. We herein report HME was cytotoxic, more potent than cisplatin, and proapoptotic to various human bladder transitional carcinoma cell lines. Of note, HME blocked STAT3 activation, evidenced by HME-elicited reduction in tyrosine 705-phosphorylated STAT3 levels constitutively expressed or induced by interleukin-6. Significantly, HME-induced cytotoxicity was abrogated in cells expressing a dominant-active STAT3 mutant (STAT3-C), confirming STAT3 blockage as a pivotal mechanism of HME's cytotoxic action. We further revealed that survivin was downregulated by HME, while its levels were rescued in STAT3-C-expressing cells. Moreover, survivin overexpression abolished HME-induced cytotoxicity, illustrating survivin as a central downstream mediator of STAT3 targeted by HME. Lastly, HME was shown to lower tyrosine 416-phosphorylated SRC levels, suggesting that HME inhibits STAT3 by repressing the activation of SRC, a STAT3 upstream kinase. In conclusion, we present the first evidence of HME's anti-bladder cancer effect, likely proceeding by evoking apoptosis through suppression of the antiapoptotic SRC/STAT3/survivin signaling axis.

Targeting the miR-34a/LRPPRC/MDR1 axis collapse the chemoresistance in P53 inactive colorectal cancer

P53 mutation is an important cause of chemoresistance in colorectal cancer (CRC). The investigation and identification of the downstream targets and underlying molecular mechanism of chemoresistance induced by P53 abnormalities are therefore of great clinical significance. In this study, we demonstrated and reported for the first time that leucine-rich pentatricopeptide repeat-containing protein (LRPPRC) is a key functional downstream factor and therapeutic target for P53 mutation-induced chemoresistance. Due to its RNA binding function, LRPPRC specifically bound to the mRNA of multidrug resistance 1 (MDR1), increasing MDR1 mRNA stability and protein expression. In normal cells, P53 induced by chemotherapy inhibited the expression of LRPPRC via miR-34a and in turn reduced the expression of MDR1. However, chemotherapy-induced P53/miR-34a/LRPPRC/MDR1 signalling pathway activation was lost when P53 was mutated. Additionally, the accumulated LRPPRC and MDR1 promoted drug resistance. Most importantly, gossypol-acetic acid (GAA) was recently reported by our team as the first specific inhibitor of LRPPRC. In CRC cells with P53 mutation, GAA effectively induced degradation of the LRPPRC protein and reduced chemoresistance. Both in vivo and in vitro experiments revealed that combination chemotherapy with GAA and 5-fluorouracil (5FU) yielded improved treatment outcomes. In this study, we reported a novel mechanism and target related to P53-induced drug resistance and provided corresponding interventional strategies for the precision treatment of CRC.

Interleukin-11/gp130 upregulates MMP-13 expression and cell migration in OSCC by activating PI3K/Akt and AP-1 signaling

Oral squamous cell carcinoma (OSCC) is an extremely common head and neck cancer with a poor 5-year survival rate, especially in cases of metastatic disease. Interleukin (IL)-11 reportedly promotes cell growth and the epithelial-mesenchymal transition process in metastasis. However, the molecular mechanisms of IL-11 in OSCC metastasis are unclear. This study found that IL-11 upregulates matrix metalloproteinase 13 (MMP-13) expression in OSCC via the IL-11 receptor alpha subunit/glycoprotein 130 receptors that activate phosphatidyl-inositol 3-kinase, Ak strain transforming, and activator protein 1 signaling, which subsequently enhance MMP-13-induced tumor metastasis. TIMER2.0 analysis revealed a positive correlation between MMP-13 and IL-11 levels (r = 0.454). Moreover, a strong positive association was observed between higher levels of IL-11 expression in OSCC tissue (p < 0.01), lymph node metastasis (p = 0.0154), and clinical disease stage (p = 0.0337). IL-11 knockdown suppressed the migration of OSCC cells (p < 0.05). The evidence indicates that IL-11 can serve as a new molecular therapeutic target in OSCC metastasis.

Identification of therapeutically potential targets and their ligands for the treatment of OSCC

Recent advancements in cancer biology have revealed molecular changes associated with carcinogenesis and chemotherapeutic exposure. The available information is being gainfully utilized to develop therapies targeting specific molecules involved in cancer cell growth, survival, and chemoresistance. Targeted therapies have dramatically increased overall survival (OS) in many cancers. Therefore, developing such targeted therapies against oral squamous cell carcinoma (OSCC) is anticipated to have significant clinical implications. In the current work, we have identified drug-specific sensitivity-related prognostic biomarkers (BOP1, CCNA2, CKS2, PLAU, and SERPINE1) using gene expression, Cox proportional hazards regression, and machine learning in OSCC. Dysregulation of these markers is significantly associated with OS in many cancers. Their elevated expression is related to cellular proliferation and aggressive malignancy in various cancers. Mechanistically, inhibition of these biomarkers should significantly reduce cellular proliferation and metastasis in OSCC and should result in better OS. It is pertinent to note that no effective small-molecule candidate has been identified against these biomarkers to date. Therefore, a comprehensive in silico drug design strategy assimilating homology modeling, extensive molecular dynamics (MD) simulation, and ensemble molecular docking has been applied to identify potential compounds against identified targets, and potential molecules have been identified. We hope that this study will help in deciphering potential genes having roles in chemoresistance and a significant impact on OS. It will also result in the identification of new targeted therapeutics against OSCC.

Tanshinone IIA-regulation of IL-6 antagonizes PM2 .5 -induced proliferation of human bronchial epithelial cells via a STAT3/miR-21 reciprocal loop

Particulate matter 2.5 (PM_2.5 ), a component of atmospheric particulate matter, leads to changes in gene expression and cellular functions. Epidemiological evidence confirms that PM_2.5 has a positive correlation with lung injury. However, the molecular mechanisms involved remain poorly understood, and preventive methods are needed. In the present study, with human bronchial epithelial (HBE) cells in culture, we showed that low concentrations of PM_2.5 resulted in acceleration of the G1/S transition and cell proliferation. Consistent with these effects, expression of the pro-inflammatory factor interleukin-6 (IL-6) was elevated in HBE cells exposed to PM_2.5 . Accordingly, signal transducer and activator of transcription 3 (STAT3) was activated, which down-regulated expression of cyclin D1. In addition, PM_2.5 exposure led to higher levels of miR-21, and there was a reciprocal loop between miR-21 and STAT3. For HBE cells, tanshinone IIA (Tan IIA) reversed the PM_2.5 -induced cell cycle alteration and cell proliferation, and reduced the expression of cytokines (IL-6, STAT3, and miR-21). These results show that, for HBE cells, Tan IIA attenuates the PM_2.5 -induced G1/S alteration and cell proliferation, and indicate that it has potential clinical application for PM_2.5 -induced respiratory injuries.

Long-Noncoding RNA ANCR Activates the Hedgehog Signaling Pathway to Promote Basal Cell Carcinoma Progression by Binding to PTCH

Purpose

The long non-coding RNA (lncRNA) anti-differentiation noncoding RNA (ANCR) is closely related to the occurrence and development of various malignancies. However, its expression and potential role in basal cell carcinoma (BCC) have not been established. In this study, we characterized the effects of ANCR in BCC and its underlying mechanism.

Methods

The expression of ANCR in BCC tissues and cells was detected by qRT-PCR. Proliferation, invasion, migration and apoptosis of ANCR overexpressed or knock down TE354.T and A431 cells were examined by CCK8, transwell assay, wound healing assay and flow cytometry analysis, respectively. Western blot was performed to measure the expression of apoptosis-related proteins (BAX, BCL2 and Cleaved-caspase3), epithelial-mesenchymal transformation-related proteins (E-cadherin, N-cadherin, vimentin and β-catenin), and Hedgehog-pathway-related proteins (PTCH, GLI1 and SMO). RNA pull-down assay was used to analyze the relationship between ANCR and PTCH. The effect of ANCR on BCC growth in vivo was analyzed using xenograft model. TUNEL assay was used to determine the cell apoptosis.

Results

ANCR and Hedgehog pathway were more highly expressed in BCC tissues than in adjacent normal tissues. ANCR overexpression substantially promoted BCC cell proliferation, invasion, and migration, inhibited apoptosis, and up-regulated BCL2 and decreased the expression of BAX and Cleaved-caspase3 proteins. Additionally, the upregulation of N-cadherin, vimentin, β-catenin, PTCH, GLI1, and SMO expression, and downregulation of E-cadherin expression were observed after ANCR overexpression. Moreover, ANCR knockdown had the opposite effects. An RNA pull-down assay further revealed that ANCR is specifically bound to PTCH. In vivo experiments also showed that ANCR overexpression significantly increased tumor growth and decreased apoptosis, which was reversed by cyclopamine, a specific inhibitor of the Hedgehog signaling pathway.

Conclusion

ANCR activates the Hedgehog signaling pathway by binding to PTCH, thereby promoting BCC progression; accordingly, ANCR could be a candidate therapeutic target in BCC.

A review on the role of DANCR in the carcinogenesis

DANCR is an RNA gene located on chr4. This gene has several splice variants. Up-regulation of DANCR has been reported in many types of cancers. This lncRNA is mainly located in the cytoplasm and regulates genes expression at post-transcriptional level. In fact, it acts as a molecular sponge for a variety of miRNAs, including miR-874-3P, miR-335, miR-149, miR-4319, miR-758-3p, miR-216a-5p, miR-874-3p, miR-33a-5p, miR-335-5p, miR-145-3p, miR-665, miR-345-5p and miR-125b-5p. DANCR also regulates activity of PI3K/AKT/NF-κB, Wnt/β-catenin, ERK/SMAD, MAPK, IL-6/JAK1/STAT3, Smad2/3, p53, FAK/PI3K/AKT/GSK3β/Snail pathways. In the current narrative review article, we summarize the roles of DANCR in the carcinogenesis, with an especial emphasis on its role in the development of osteosarcoma and lung, liver, pancreatic and colorectal cancers.

HSF1 facilitates the multistep process of lymphatic metastasis in bladder cancer via a novel PRMT5-WDR5-dependent transcriptional program

Background

Lymphatic metastasis has been associated with poor prognosis in bladder cancer patients with limited therapeutic options. Emerging evidence shows that heat shock factor 1 (HSF1) drives diversified transcriptome to promote tumor growth and serves as a promising therapeutic target. However, the roles of HSF1 in lymphatic metastasis remain largely unknown. Herein, we aimed to illustrate the clinical roles and mechanisms of HSF1 in the lymphatic metastasis of bladder cancer and explore its therapeutic potential.

Methods

We screened the most relevant gene to lymphatic metastasis among overexpressed heat shock factors (HSFs) and heat shock proteins (HSPs), and analyzed its clinical relevance in three cohorts. Functional in vitro and in vivo assays were performed in HSF1‐silenced and ‐regained models. We also used Co‐immunoprecipitation to identify the binding proteins of HSF1 and chromatin immunoprecipitation and dual‐luciferase reporter assays to investigate the transcriptional program directed by HSF1. The pharmacological inhibitor of HSF1, KRIBB11, was evaluated in popliteal lymph node metastasis models and patient‐derived xenograft models of bladder cancer.

Results

HSF1 expression was positively associated with lymphatic metastasis status, tumor stage, advanced grade, and poor prognosis of bladder cancer. Importantly, HSF1 enhanced the epithelial‐mesenchymal transition (EMT) of cancer cells in primary tumor to initiate metastasis, proliferation of cancer cells in lymph nodes, and macrophages infiltration to facilitate multistep lymphatic metastasis. Mechanistically, HSF1 interacted with protein arginine methyltransferase 5 (PRMT5) and jointly induced the monomethylation of histone H3 at arginine 2 (H3R2me1) and symmetric dimethylation of histone H3 at arginine 2 (H3R2me2s). This recruited the WD repeat domain 5 (WDR5)/mixed‐lineage leukemia (MLL) complex to increase the trimethylation of histone H3 at lysine 4 (H3K4me3); resulting in upregulation of lymphoid enhancer‐binding factor 1 (LEF1), matrix metallopeptidase 9 (MMP9), C‐C motif chemokine ligand 20 (CCL20), and E2F transcription factor 2 (E2F2). Application of KRIBB11 significantly inhibited the lymphatic metastasis of bladder cancer with no significant toxicity.

Conclusion

Our findings reveal a novel transcriptional program directed by the HSF1‐PRMT5‐WDR5 axis during the multistep process of lymphatic metastasis in bladder cancer. Targeting HSF1 could be a multipotent and promising therapeutic strategy for bladder cancer patients with lymphatic metastasis.

High serum exosomal long non-coding RNA DANCR expression confers poor prognosis in patients with breast cancer

Background

Exosomal long non‐coding RNAs (lncRNAs) serve as excellent candidate biomarkers for clinical applications. The expression of differentiation antagonizing non‐protein coding RNA (DANCR) has been shown to be decreased in breast cancer (BC) tissues and cell lines. However, the clinical value of circulating exosomal DANCR in BC has not been explored.

Methods

A total of 120 BC patients, 70 benign breast disease (BBD) patients, and 105 healthy women were recruited in this study. Total RNA was extracted from serum samples, and the level of serum exosomal lncRNA DANCR was evaluated by quantitative real‐time reverse transcription‐polymerase chain reaction (qRT‐PCR).

Results

Serum exosomal lncRNA DANCR levels were significantly higher in BC patients than in BBD patients and normal controls. The diagnostic performance of serum exosomal lncRNA DANCR was good, and the combination of serum exosomal lncRNA DANCR, CA153, and CEA greatly improved the diagnostic accuracy for BC. High serum exosomal lncRNA DANCR level was associated with various clinicopathological variables including lymph node metastasis, ER status, HER2 status, and TNM stage. In addition, the BC patients in the high serum exosomal lncRNA DANCR expression group had significantly shorter 5‐year overall survival time. Multivariate analysis demonstrated that serum exosomal lncRNA DANCR was an independent risk factor for BC.

Conclusion

Serum exosomal lncRNA DANCR may be a useful non‐invasive biomarker for the clinical diagnosis and prognosis of BC.

Identification of a chromatin regulator signature and potential candidate drugs for bladder cancer

Background

Bladder cancer (BLCA) is a malignant tumor with a dismay outcome. Increasing evidence has confirmed that chromatin regulators (CRs) are involved in cancer progression. Therefore, we aimed to explore the function and prognostic value of CRs in BLCA patients.

Methods

Chromatin regulators (CRs) were acquired from the previous top research. The mRNA expression and clinical information were downloaded from TCGA and GEO datasets. Cox regression analysis and least absolute shrinkage and selection operator (LASSO) regression analysis were performed to select the prognostic gene and construct the risk model for predicting outcome in BLCA. The Kaplan-Meier analysis was used to assess the prognosis between high- and low-risk groups. We also investigated the drug sensitivity difference between high- and low-risk groups. CMAP dataset was performed to screen the small molecule drugs for treatment.

Results

We successfully constructed and validated an 11 CRs-based model for predicting the prognosis of patients with BLCA. Moreover, we also found 11 CRs-based model was an independent prognostic factor. Functional analysis suggested that CRs were mainly enriched in cancer-related signaling pathways. The CR-based model was also correlated with immune cells infiltration and immune checkpoint. Patients in the high-risk group were more sensitive to several drugs, such as mitomycin C, gemcitabine, cisplatin. Eight small molecule drugs could be beneficial to treatment for BLCA patients.

Conclusion:

In conclusion, our study provided novel insights into the function of CRs in BLCA. We identified a reliable prognostic biomarker for the survival of patients with BLCA.

Comprehensive Analysis of N6-Methylandenosine-Related Long Non-Coding RNAs Signature in Prognosis and Tumor Microenvironment of Bladder Cancer

To investigate the role of N6-methyladenosine (m6A)- related long non-coding RNAs (lncRNAs) in bladder cancer (BC). 50 m6A-related lncRNAs were screened out and were correlated with prognosis from BC samples in The Cancer Genome Atlas (TCGA). The lncRNAs were subdivided into cluster 1 and cluster 2 with consensus cluster analysis, and it was found that lncRNAs in cluster 2 were associated with poor prognosis and increased PD-L1 expression. Gene set enrichment analysis (GSEA) revealed tumor-related pathways in cluster 2. Through least absolute shrinkage and selection operator (LASSO) Cox regression analysis, univariate and multivariate Cox regression, and ROC analyses, 14 prognostic lncRNAs were selected and used to construct the m6A-related lncRNA prognostic signature (m6A-LPS), furthermore, that m6A-LPS was as a valuable independent prognostic factor. Interestingly, the m6A-LPS risk score was positively correlated with the immune score, PD-L1 expression, and the infiltration of immune cell subtypes in BC. SNHG16, a member of the high-risk group based on m6A-LPS, was highly expressed in BC tissues and cell lines and interfered with siRNA resulted in suppressed proliferation, migration, and invasion in vitro. Our study illustrates the role of m6A-related lncRNAs in BC. The m6A-LPS may be an important regulatory target of the tumor microenvironment (TME) in BC.

High expression of small nucleolar RNA host gene 3 predicts poor prognosis and promotes bone metastasis in prostate cancer by activating transforming growth factor-beta signaling

Bone metastasis is closely related to tumor death in prostate cancer (PC). Long noncoding RNA small nucleolar RNA host gene 3 (SNHG3) has been implicated in the initiation and progression of multiple human cancers. Nevertheless, the biological function of SNHG3 in PC has not been elucidated. Our results indicated that SNHG3 was upregulated in bone metastasis-positive PC tissues compared to bone metastasis-negative PC tissues and adjacent normal tissues. High expression of SNHG3 indicates advanced clinicopathological features and predicts poor prognosis in patients with PC. Meanwhile, SNHG3 knockdown suppressed the proliferation, migration, and invasion abilities of PC cells and inhibited PC cell metastasis to the bone. Mechanistically, SNHG3 enhanced the expression of transforming growth factor beta receptor 1 (TGFBR1) and activated transforming growth factor-Beta (TGF-β) signaling by targeting miR-214-3p. Our study demonstrated the novel role of the SNHG3/miR-214-3p/TGF-β axis in tumor growth and bone metastasis in PC, indicating that SNHG3 may act as a biomarker and promising therapeutic target against PC.

DGUOK-AS1 acts as a tumorpromoter through regulatingmiR-204-5p/IL-11 axis in breast cancer

Breast cancer is one of the most lethal malignancies among women; however, the underlying molecular mechanism involved in the progression and metastasis of breast cancer remains unclear. Numerous studies have confirmed that long noncoding RNAs are abnormally expressed in breast cancer and play crucial roles in cell proliferation and metastasis. In the study, we evaluated the functional role and detailed mechanism of DGUOK-AS1 in breast cancer progression and metastasis. DGUOK-AS1 knockdown suppressed proliferation, migration, and invasion of breast cancer cells in vitro and in vivo. Mechanistically, miR-204-5p was identified as an inhibitory target of DGUOK-AS1, which served as a tumor suppressor in breast cancer. Significantly, we found that the ectopic expression of miR-204-5p could counteract DGUOK-AS1-mediated promotion of cell proliferation and metastasis in breast cancer. Moreover, IL-11 was found to be the downstream target of miR-204-5p, and DGUOK-AS1 could protect IL-11 from miR-204-5p-mediated degradation. DGUOK-AS1 overexpression promoted breast cancer cell migration, angiogenesis, and macrophage migration, mediating by the increased secretion of IL-11, which was extremely important for cancer progression. Collectively, our studies reveal that DGUOK-AS1/miR-204-5p/IL-11 axis plays a significant role in the progression and metastasis of breast cancer, and DGUOK-AS1 might be a novel biomarker and therapeutic target for breast cancer.

Long noncoding RNAs to predict postoperative recurrence in bladder cancer and to develop a new molecular classification system

BACKGROUND

Reliable molecular markers are much needed for early prediction of recurrence in muscle-invasive bladder cancer (MIBC) patients. We aimed to build a long-noncoding RNA (lncRNA) signature to improve recurrence prediction and lncRNA-based molecular classification of MIBC.

METHODS

LncRNAs of 320 MIBC patients from the Cancer Genome Atlas (TCGA) database were analyzed, and a nomogram was established. A molecular classification system was created, and immunotherapy and chemotherapy response predictions, immune score analysis, immune infiltration analysis, and mutational data analysis were conducted. Survival analysis validation was also performed.

RESULTS

An eight-lncRNA signature classifed the patients into high- and low-risk subgroups, and these groups had significantly different (disease-free survival) DFS. The ability of the eight-lncRNA signature to make an accurate prognosis was tested using a validation dataset from our samples. The nomogram achieved a C-index of 0.719 (95% CI, 0.674-0.764). Time-dependent receiver operating characteristic curve (ROC) analysis indicated the superior prognostic accuracy of nomograms for DFS prediction (0.76, 95% CI, 0.697-0.807). Further, the four clusters (median DFS = 11.8, 15.3, 17.9, and 18.9 months, respectively) showed a high frequency of TTN (cluster 1), fibroblast growth factor receptor-3 (cluster 2), TP53 (cluster 3), and TP53 mutations (cluster 4), respectively. They were enriched with M2 macrophages (cluster 1), CD8⁺ T cells (cluster 2), M0 macrophages (cluster 3), and M0 macrophages (cluster 4), respectively. Clusters 2 and 3 demonstrated potential sensitivity to immunotherapy and insensitivity to chemotherapy, whereas cluster 4 showed potential insensitivity to immunotherapy and sensitivity to chemotherapy.

CONCLUSIONS

The eight-lncRNA signature risk model may be a reliable prognostic signature for MIBC, which provides new insights into prediction of recurrence of MIBC. The model may help clinical decision and eventually benefit patients.

Long Non-coding RNA DANCR in Cancer: Roles, Mechanisms, and Implications

Long non-coding RNA (lncRNA) DANCR (also known as ANCR)—differentiation antagonizing non-protein coding RNA, was first reported in 2012 to suppress differentiation of epithelial cells. Emerging evidence demonstrates that DANCR is a cancer-associated lncRNA abnormally expressed in many cancers (e.g., lung cancer, gastric cancer, breast cancer, hepatocellular carcinoma). Increasing studies suggest that the dysregulation of DANCR plays critical roles in cancer cell proliferation, apoptosis, migration, invasion, and chemoresistance in vitro and tumor growth and metastasis in vivo. Mechanistic analyses show that DANCR can serve as miRNA sponges, stabilize mRNAs, and interact with proteins. Recent research reveals that DANCR can be detected in many body fluids such as serum, plasma, and exosomes, providing a quick and convenient method for cancer monitor. Thus DANCR can be used as a promising diagnostic and prognostic biomarker and therapeutic target for various types of cancer. This review focuses on the role and mechanism of DANCR in cancer progression with an emphasis on the clinical significance of DANCR in human cancers.

The Role of Long Non-coding RNA, Nuclear Enriched Abundant Transcript 1 (NEAT1) in Cancer and Other Pathologies

Nuclear enriched abundant transcript 1 (NEAT1), consisting of two kinds of lncRNAs of 3.7 kB NEAT1-1 and 23 kB NEAT1-2, can be highly expressed in organs and tissues such as the ovary, prostate, colon, and pancreas, and is involved in paraspeckle formation and mRNA editing and gene expression. Therefore, NEAT1 is a potential biomarker for the treatment of a variety of diseases, which may be caused by two factors (isoforms of NEAT1 and NEAT1 sponging miRNA as ceRNA). However, there is still much confusion about the mechanism and downstream effector between the abnormal expression of NEAT1 and various diseases. This review summarizes recent research progress on NEAT1 in cancer and other pathologies and provides a more reliable theoretical basis for the treatment of related diseases.

LncRNA SNHG17 interacts with LRPPRC to stabilize c-Myc protein and promote G1/S transition and cell proliferation

Oncogenic c-Myc is a master regulator of G1/S transition. Long non-coding RNAs (lncRNAs) emerge as new regulators of various cell activities. Here, we found that lncRNA SnoRNA Host Gene 17 (SNHG17) was elevated at the early G1-phase of cell cycle. Both gain- and loss-of function studies disclosed that SNHG17 increased c-Myc protein level, accelerated G1/S transition and cell proliferation, and consequently promoted tumor cell growth in vitro and in vivo. Mechanistically, the 1-150-nt of SNHG17 physically interacted with the 1035-1369-aa of leucine rich pentatricopeptide repeat containing (LRPPRC) protein, and disrupting this interaction abrogated the promoting role of SNHG17 in c-Myc expression, G1/S transition, and cell proliferation. The effect of SNHG17 in stimulating cell proliferation was attenuated by silencing c-Myc or LRPPRC. Furthermore, silencing SNHG17 or LRPPRC increased the level of ubiquitylated c-Myc and reduced the stability of c-Myc protein. Analysis of human hepatocellular carcinoma (HCC) tissues revealed that SNHG17, LRPPRC, and c-Myc were significantly upregulated in HCC, and they showed a positive correlation with each other. High level of SNHG17 or LRPPRC was associated with worse survival of HCC patients. These data suggest that SNHG17 may inhibit c-Myc ubiquitination and thus enhance c-Myc level and facilitate proliferation by interacting with LRPPRC. Our findings identify a novel SNHG17-LRPPRC-c-Myc regulatory axis and elucidate its roles in G1/S transition and tumor growth, which may provide potential targets for cancer therapy.

The Emerging Functions of Circular RNAs in Bladder Cancer

Simple Summary

The role of circular RNAs has made breakthroughs in understanding the mechanisms of tumor development. Bladder cancer has an increasing incidence, high recurrence rate, high metastatic potential, poor prognosis, and susceptibility to chemotherapy resistance. Thus, it is essential to identify molecules related to the tumorigenesis of bladder cancer. In this review, we summarize current knowledge about the expression of circular RNAs in bladder cancer and their implications in vesical carcinogenesis. We further discuss the limitations of existing studies and provide an outlook for future studies in the hopes of better revealing the association between circular RNAs and bladder cancer.

Abstract

Bladder cancer (BC) is among the top ten most common cancer types worldwide and is a serious threat to human health. Circular RNAs (circRNAs) are a new class of non-coding RNAs generated by covalently closed loops through back-splicing. As an emerging research hotspot, circRNAs have attracted considerable attention due to their high conservation, stability, abundance, and specificity of tissue development. Accumulating evidence has revealed different form of circRNAs are closely related to the malignant phenotype, prognosis and chemotherapy resistance of BC, suggesting that different circRNAs may be promising biomarkers and have therapeutic significance in BC. The intention of this review is to summarize the mechanisms of circRNA-mediated BC progression and their diagnostic and prognostic value as biomarkers, as well as to further explore their roles in chemotherapy resistance.

Discovery and Validation of Nitroxoline as a Novel STAT3 Inhibitor in Drug-resistant Urothelial Bladder Cancer

Repeated cycles of first-line chemotherapy drugs such as doxorubicin (DOX) and cisplatin (CIS) trigger frequent chemoresistance in recurrent urothelial bladder cancer (UBC). Nitroxoline (NTX), an antibiotic to treat urinary tract infections, has been recently repurposed for cancer treatment. Here we aimed to investigate whether NTX suppresses drug-resistant UBC and its molecular mechanism. The drug-resistant cell lines T24/DOX and T24/CIS were established by continual exposure of parental cell line T24 to DOX and CIS, respectively. T24/DOX and T24/CIS cells were resistant to DOX and CIS, respectively, but they were sensitive to NTX time- and dose-dependently. Overexpressions of STAT3 and P-glycoprotein (P-gp) were identified in T24/DOX and T24/CIS, which could be reversed by NTX. Western blot revealed that NTX downregulated p-STAT3, c-Myc, Cyclin D1, CDK4, CDK6, Bcl-xL, Mcl-1, and Survivin, which were further confirmed by Stattic, a selective STAT3 inhibitor. In vivo, NTX exhibited the significant anti-tumor effect in T24/DOX and T24/CIS tumor-bearing mice. These results suggested that NTX-induced P-gp reversal, G0/G1 arrest, and apoptosis in drug-resistant UBC were mediated by inhibition of STAT3 signaling. Our findings repurpose NTX as a novel STAT3 inhibitor to induce P-gp reversal, G0/G1 arrest, and apoptosis in drug-resistant UBC.

CRISPR activation of long non-coding RNA DANCR promotes bone regeneration

Healing of large calvarial bone defects in adults adopts intramembranous pathway and is difficult. Implantation of adipose-derived stem cells (ASC) that differentiate towards chondrogenic lineage can switch the bone repair pathway and improve calvarial bone healing. Long non-coding RNA DANCR was recently uncovered to promote chondrogenesis, but its roles in rat ASC (rASC) chondrogenesis and bone healing stimulation have yet to be explored. Here we first verified that DANCR expression promoted rASC chondrogenesis, thus we harnessed CRISPR activation (CRISPRa) technology to upregulate endogenous DANCR, stimulate rASC chondrogenesis and improve calvarial bone healing in rats. We generated 4 different dCas9-VPR orthologues by fusing a tripartite transcription activator domain VPR to catalytically dead Cas9 (dCas9) derived from 4 different bacteria, and compared the degree of activation using the 4 different dCas9-VPR. We unveiled surprisingly that the most commonly used dCas9-VPR derived from Streptococcus pyogenes barely activated DANCR. Nonetheless dCas9-VPR from Staphylococcus aureus (SadCas9-VPR) triggered efficient activation of DANCR in rASC. Delivery of SadCas9-VPR and the associated guide RNA into rASC substantially enhanced chondrogenic differentiation of rASC and augmented cartilage formation in vitro. Implantation of the engineered rASC remarkably potentiated the calvarial bone healing in rats. Furthermore, we identified that DANCR improved the rASC chondrogenesis through inhibition of miR-203a and miR-214. These results collectively proved that DANCR activation by SadCas9-VPR-based CRISPRa provides a novel therapeutic approach to improving calvarial bone healing.

Long non‑coding RNA DANCR represses the viability, migration and invasion of multiple myeloma cells by sponging miR‑135b‑5p to target KLF9

Multiple myeloma (MM) is a malignancy of plasma cells that leads to marrow failure and bone lesions. Numerous studies have verified the link between long non‑coding RNAs (lncRNAs) and MM. The present study aimed to examine the role and underlying mechanism of differentiation antagonizing non‑protein coding RNA (DANCR) in MM cells. The relative expression levels of DANCR, microRNA (miR)‑135b‑5p and Krüppel‑like factor 9 (KLF9) were examined using reverse transcription‑quantitative PCR. Cell viability was assessed using the MTT assay, while relative cell migration and invasion were evaluated using Transwell assays. Moreover, the dual‑luciferase reporter assay was used to examine the interplay between DANCR, miR‑135b‑5p and KLF9. Western blotting was performed to determine the expression level of KLF9. It was found that lncRNA DANCR and KLF9 were downregulated, while miR‑135b‑5p was upregulated in the serum of patients with MM and in MM cells compared with the controls. Overexpressing DANCR or knocking down miR‑135b‑5p reduced the viability of the MM cells, as well as restrained MM cells from migrating and invading. Furthermore, DANCR directly targeted miR‑135b‑5p and was negatively correlated with miR‑135b‑5p. It was also found that KLF9 was targeted by miR‑135b‑5p and was inversely correlated with miR‑135b‑5p expression. The impact of lncRNA DANCR‑mediated suppression on cell viability, invasion and migration was partially abolished by short hairpin RNA KLF9 or miR‑135b‑5p mimics transfection in MM cells. Thus, it was suggested that lncRNA DANCR repressed the viability, migration and invasion of MM cells by sponging miR‑135b‑5p to target KLF9.

LncCCLM inhibits lymphatic metastasis of cervical cancer by promoting STAU1-mediated IGF-1 mRNA degradation

Cervical cancer (CC) patients with lymph node (LN) metastasis often have an extremely poor prognosis. However, the precise molecular mechanisms involved in LN metastasis of CC remain largely unknown. Herein, through RNA screening, we identified a novel long noncoding RNA (lncRNA), LncCCLM, that was downregulated in cervical cancer tissues and closely associated with lymphatic metastasis in cervical cancer patients. Gain-of-function and loss-of-function studies in CC cells demonstrated that LncCCLM inhibited cervical cancer-associated lymphangiogenesis, and CC cell migration and invasion in vitro and suppressed LN metastasis in vivo, but did not affect the growth of CC cells. Mechanistically, LncCCLM localized in the cytoplasm and interacted with staufen double-stranded RNA binding protein 1 (STAU1), promoting the binding of the STAU1 protein to the 3' untranslated region (3'UTR) of insulin-like growth factor 1 (IGF-1) mRNA, which accelerated the degradation of IGF-1 mRNA and decreased the IGF-1 protein level, ultimately reducing lymphangiogenesis and lymphatic metastasis in cervical cancer. Collectively, our findings suggest that LncCCLM acts as a tumor suppressor and may be used as a prognostic biomarker and therapeutic target for clinical intervention in LN-metastatic cervical cancer.

Targeting WD repeat domain 5 enhances chemosensitivity and inhibits proliferation and programmed death-ligand 1 expression in bladder cancer

Background

Chemotherapy and/or immunotherapy are first-line treatments for advanced muscle-invasive bladder cancer (BCa), but the unsatisfactory objective response rate to these treatments yields poor 5-year patient survival. Discovery of therapeutic targets essential for BCa maintenance is critical to improve therapy response in clinic. This study evaluated the role of targeting WD repeat domain 5 (WDR5) with the small molecule compound OICR-9429 and whether it could be used to treat bladder cancer.

Methods

We analysed the expression and clinical prognosis of WDR5 in a TCGA cohort. The pharmacological role of OICR-9429 was further investigated in vitro and in vivo. RNA sequencing, western blot, and chromatin immunoprecipitation (ChIP) were utilized to explored the mechanism underlying OICR-9429-induced WDR5 inhibition.

Results

First, we found that WDR5 expression was upregulated in BCa and was associated with histologic grade, metastasis status, histologic subtype, and molecular subtype. High WDR5 expression level was also correlated with shorter overall survival (OS) in BCa. The WDR5 inhibitor OICR-9429 reduced cell viability by decreasing H3K4me3 levels but not WDR5 levels in T24, UM-UC-3, and TCCSUP BCa cells. OICR-9429 suppressed the proliferation of BCa cells by blocking the G1/S phase transition. Next, OICR-9429 enhanced apoptosis and chemosensitivity to cisplatin in BCa cells. In addition, OICR-9429 independently inhibited the motility and metastatic behaviour of BCa cells. In vivo experiments further revealed that OICR-9429 suppressed tumour growth, enhanced chemosensitivity, and reduced the toxicity of cisplatin in BCa. Notably, WDR5 was positively correlated with programmed death-ligand 1 (PD-L1) expression, and OICR-9429 suppressed immune evasion by blocking PD-L1 induced by IFN-γ. Mechanistically, some cell cycle-, antiapoptosis-, DNA repair-, metastasis-, and immune evasion-related genes, including BIRC5, XRCC2, CCNB1, CCNE2, PLK1, AURKA, FOXM1, and PD-L1 were identified to be directly regulated by OICR-9429 in a H3K4me3-dependent manner.

Conclusions

Our novel finding is that the WDR5 inhibitor, OICR-9429, suppressed proliferation, metastasis and PD-L1-based immune evasion while enhancing apoptosis and chemosensitivity to cisplatin in BCa by blocking the WDR5-MLL complex mediating H3K4me3 in target genes. Hence, our findings offer insight into a multipotential anticancer compound, OICR-9429, which enhances the antitumour effect of cisplatin or immunotherapy in BCa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01989-5.

Long Non-coding RNA MEG3 Promotes Pyroptosis in Testicular Ischemia-Reperfusion Injury by Targeting MiR-29a to Modulate PTEN Expression

Increasing evidence shows that the abnormal long non-coding RNAs (lncRNAs) expression is closely related to ischemia-reperfusion injury (I/R) progression. Studies have previously described that lncRNA MEG3 regulates pyroptosis in various organs I/R. Nevertheless, the related mechanisms of MEG3 in testicular I/R has not been clarified. The aim of this research is to unravel underlying mechanisms of the regulation of pyroptosis mediated by MEG3 during testicular I/R. We have established a testicular torsion/detorsion (T/D) model and an oxygen-glucose deprivation/reperfusion (OGD/R)-treated spermatogenic cell model. Testicular ischemic injury was assessed by H&E staining. Western blotting, quantitative real-time PCR, MDA, and SOD tests and immunohistochemistry measured the expression of MEG3 and related proteins and the level of ROS production in testicular tissues. Quantitative real-time PCR and western blotting determined the relative expression of MEG3, miR-29a, and relevant proteins in GC-1. Cell viability and cytotoxicity were measured by CCK-8 and LDH assays. Secretion and expression levels of inflammatory proteins were determined by ELISA, immunofluorescence and western blotting. The interaction among MEG3, miR-29a, and PTEN was validated through a dual luciferase reporter assay and Ago2-RIP. In this research, we identified that MEG3 was upregulated in animal specimens and GC-1. In loss of function or gain of function assays, we verified that MEG3 could promote pyroptosis. Furthermore, we found that MEG3 negatively regulated miR-29a expression at the posttranscriptional level and promoted PTEN expression, and further promoted pyroptosis. Therefore, we explored the interaction among MEG3, miR-29a and PTEN and found that MEG3 directly targeted miR-29a, and miR-29a targeted PTEN. Overexpression of miR-29a effectively eliminated the upregulation of PTEN induced by MEG3, indicating that MEG3 regulates PTEN expression by targeting miR-29a. In summary, our research indicates that MEG3 contributes to pyroptosis by regulating miR-29a and PTEN during testicular I/R, indicating that MEG3 may be a potential therapeutic target in testicular torsion.

USP24-GSDMB complex promotes bladder cancer proliferation via activation of the STAT3 pathway

Background: Bladder cancer is the fourth and tenth most common malignancy in men and women worldwide, respectively. One of the main reasons for the unsatisfactory therapeutic control of bladder cancer is that the molecular biological mechanism of bladder cancer is complex. Gasdermin B (GSDMB) is one member of the gasdermin family and participates in the regulation of cell pyroptosis. The role of GSDMB in bladder cancer has not been studied to date. Methods: TCGA database was used to exam the clinical relevance of GSDMB. Functional assays such as MTT assay, Celigo fluorescent cell-counting assay, Annexin V-APC assay and xenografts were used to evaluate the biological role of GSDMB in bladder cancer. Mass spectrometry and immunoprecipitation were used to detect the protein interaction between GSDMB and STAT3, or GSDMB and USP24. Western blot and immunohistochemistry were used to study the relationship between USP24, GSDMB and STAT3. Results: In this study, bioinformatics analysis indicated that the mRNA expression level of GSDMB in bladder cancer tissues was higher than that in adjacent normal tissues. Then, we showed that GSDMB promoted bladder cancer progression. Furthermore, we demonstrated that GSDMB interacted with STAT3 to increase the phosphorylation of STAT3 and modulate the glucose metabolism and promote tumor growth in bladder cancer cells. Besides, we also showed that USP24 stabilized GSDMB to activate STAT3 signaling, which was blocked by the USP24 inhibitor. Conclusions: We suggested that aberrantly up-regulated GSDMB was responsible for enhancing the growth and invasion ability of bladder cancer cells. Then, we showed that GSDMB could bind to STAT3 and activate STAT3 signaling in bladder cancer. Furthermore, we also demonstrated that USP24 interacted with GSDMB and prevented GSDMB from degradation in bladder cancer cells. Therefore, the USP24/GSDMB/STAT3 axis may be a new targetable signaling pathway for bladder cancer treatment.

m6 A modification of lncRNA PCAT6 promotes bone metastasis in prostate cancer through IGF2BP2-mediated IGF1R mRNA stabilization

BACKGROUND

Bone metastasis is the leading cause of tumor-related death in prostate cancer (PCa) patients. Long noncoding RNAs (lncRNAs) have been well documented to be involved in the progression of multiple cancers. Nevertheless, the role of lncRNAs in PCa bone metastasis remains largely unclear.

METHODS

The expression of prostate cancer-associated transcripts was analyzed in published datasets and further verified in clinical samples and cell lines by RT-qPCR and in situ hybridization assays. Colony formation assay, MTT assay, cell cycle analysis, EdU assay, Transwell migration and invasion assays, wound healing assay, and in vivo experiments were carried out to investigate the function of prostate cancer-associated transcript 6 (PCAT6) in bone metastasis and tumor growth of PCa. Bioinformatic analysis, RNA pull-down, and RIP assays were conducted to identify the proteins binding to PCAT6 and the potential targets of PCAT6. The therapeutic potential of targeting PCAT6 by antisense oligonucleotides (ASO) was further explored in vivo.

RESULTS

PCAT6 was upregulated in PCa tissues with bone metastasis and increased PCAT6 expression predicted poor prognosis in PCa patients. Functional experiments found that PCAT6 knockdown significantly inhibited PCa cell invasion, migration, and proliferation in vitro, as well as bone metastasis and tumor growth in vivo. Mechanistically, METTL3-mediated m6 A modification contributed to PCAT6 upregulation in an IGF2BP2-dependent manner. Furthermore, PCAT6 upregulated IGF1R expression by enhancing IGF1R mRNA stability through the PCAT6/IGF2BP2/IGF1R RNA-protein three-dimensional complex. Importantly, PCAT6 inhibition by ASO in vivo showed therapeutic potential against bone metastasis in PCa. Finally, the clinical correlation of METTL3, IGF2BP2, IGF1R, and PCAT6 was further demonstrated in PCa tissues and cells.

CONCLUSIONS

Our study uncovers a novel molecular mechanism by which the m6 A-induced PCAT6/IGF2BP2/IGF1R axis promotes PCa bone metastasis and tumor growth, suggesting that PCAT6 may serve as a promising prognostic marker and therapeutic target against bone-metastatic PCa.

Circ_0000745 strengthens the expression of CCND1 by functioning as miR-488 sponge and interacting with HuR binding protein to facilitate the development of oral squamous cell carcinoma

BACKGROUND

The implication of circular RNAs (circRNAs) in human cancers has aroused much concern. In this study, we investigated the function of circ_0000745 and its potential functional mechanisms in oral squamous cell carcinoma (OSCC) to further understand OSCC pathogenesis.

METHODS

The expression of circ_0000745, miR-488 and cyclin D1 (CCND1) mRNA was measured by quantitative real-time polymerase chain reaction (qPCR). Cell proliferation capacity was assessed by cell counting kit-8 (CCK-8) assay and colony formation assay. Cell cycle progression and cell apoptosis were determined by flow cytometry assay. The protein levels of CCND1, PCNA, Cleaved-caspase 3 and HuR were detected by western blot. Animal study was conducted to identify the role of circ_0000745 in vivo. The targeted relationship was verified by dual-luciferase reporter assay, pull-down assay or RNA immunoprecipitation (RIP) assay.

RESULTS

The expression of circ_0000745 was increased in OSCC tissues and cells. Circ_0000745 downregulation inhibited OSCC cell proliferation and induced cell cycle arrest and apoptosis in vitro, as well as blocked tumor growth in vivo. MiR-488 was a target of circ_0000745, and circ_0000745 downregulation suppressed OSCC development by enriching miR-488. Besides, circ_0000745 regulated CCND1 expression by targeting miR-488. In addition, circ_0000745 regulated CCND1 expression by interacting with HuR protein. CCND1 knockdown also inhibited OSCC cell proliferation and induced cell cycle arrest and apoptosis in vitro, and CCND1 overexpression recovered the inhibitory effects on OSCC cell malignant behaviors caused by circ_0000745 downregulation.

CONCLUSIONS

Circ_0000745 regulated the expression of CCND1 partly by acting as miR-488 sponge and interacting with HuR protein, thus promoting the progression of OSCC.