CircIPO7 Promotes Nasopharyngeal Carcinoma Metastasis and Cisplatin Chemoresistance by Facilitating YBX1 Nuclear Localization

Effects of circulating RNAs on tumor metabolism in lung cancer (Review)

During the development and progression of lung cancer, cell metabolism function is altered. Thus, cells rely on aerobic glycolysis and abnormal lipid and amino acid metabolism to obtain energy and nutrients for growth, proliferation and drug resistance. Circular RNAs (circRNAs), a class of non-coding RNAs, serve important biological roles in the growth and development of tumors. Functionally, circRNAs act as molecular sponges that absorb microRNAs (miRNAs) and RNA-binding proteins and as protein scaffolds that regulate gene transcription and translation through the maintenance of mRNA stability. In addition, circRNAs are important regulators of tumor metabolism and promote tumor progression through mediating tumor cell proliferation, metastasis and the induction of chemoresistance. Results of previous studies reveal that circRNAs may serve a key role in regulating tumor metabolic processes in lung cancer, through miRNA sponging and alternative mechanisms. Thus, circRNAs demonstrate potential as therapeutic targets for lung cancer. The present study aimed to review the effects of circRNAs on lung cancer cell metabolism and provide novel insights into the clinical treatment of lung cancer. The present review may also provide a novel theoretical basis for the development of lung cancer drug targets.

Recent advances in the role of circRNA in cisplatin resistance in tumors

Cancer remains a major threat to human health, with chemotherapy serving as one of the main treatment strategies to alleviate patient suffering. However, prolonged chemotherapy often leads to the development of drug resistance, complicating treatment outcomes. Cisplatin, a commonly utilized chemotherapeutic agent, demonstrates efficacy against a range of cancers but frequently encounters resistance, posing a significant challenge in tumor management and prognosis. Drug resistance not only facilitates tumor progression but also reduces survival rates, highlighting the urgent need for innovative strategies to overcome this issue. In recent years, non-coding RNAs, particularly circular RNAs (circRNAs), have gained attention in cancer therapy due to their stability and specificity. Moreover, an increasing number of studies have reported that circRNAs are involved in cisplatin resistance across various types of cancer. This paper primarily reviews the mechanisms and roles of circRNA in mediating cisplatin resistance over the past 3 years. These findings highlight circRNAs as promising therapeutic targets for overcoming cancer drug resistance.

CircCENPM serves as a CeRNA to aggravate nasopharyngeal carcinoma metastasis and stemness via enhancing BMI1

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a malignant head and neck cancer with high mortality and dismal prognosis. Emerging research have disclosed that circRNAs are crucial gene expression regulators engaged in tumor advancement. This work aspired to identify novel oncogenic circRNA driving NPC progression.

METHODS

Bioinformatics analysis was performed to explore and predict underlying circRNA and downstream targets. Luciferase reporter assay was executed to check the binding relationship between these genes. Cell function tests were conducted using CCK-8, would healing, and flow cytometry. The stemness markers CD133, Nanog and Oct4 was detected via western blot.

RESULTS

CircCENPM was notably enhanced in NPC. Silencing of circCENPM suppressed NPC cell growth, migration, and stemness in vitro, simultaneously impeded tumorigenesis of NPC in vivo. Moreover, circCENPM could interact with miR-362-3p, whereas miR-362-3p inhibitor apparently reversed the mitigated growth and stemness induced by circCENPM knockdown in NPC cells. Furthermore, BMI1 was identified to be the downstream target of miR-362-3p, and BMI1 introduction partially offset the anti-tumor function of miR-362-3p in NPC cells.

CONCLUSION

CircCENPM functioned as a carcinogenic driver and facilitated NPC growth and stemness via miR-362-3p/BMI1 regulatory network, which provided a potential biomarker and attractive target for NPC intervention and treatment.

m6A-modified LINC02418 induces transcriptional and post-transcriptional modification of CTNNB1 via interacting with YBX1 and IGF2BP1 in colorectal cancer

Colorectal cancer (CRC) represents a significant menace to human health, but its molecular pathogenesis remains unclear. Herein, we explored the functional role of LINC02418 in CRC progression. The function of LINC02418 in CRC was determined through vitro and in vivo experiments. The molecular mechanism of LINC02418 in CRC was explored by quantitative real-time PCR (qPCR) analyses, western blot, luciferase reporter assay, methylated RNA immunoprecipitation (MeRIP) assay, RNA pull-down, RNA immunoprecipitation (RIP) assay and chromatin immunoprecipitation (ChIP) assay. The results revealed that LINC02418 expression was upregulated in CRC tissues and the high expression of LINC02418 was related to unfavorable survival of CRC patients. Besides, knockdown of LINC02418 expression resulted in the inhibition of proliferation and metastasis of CRC cells in vitro and in vivo. Mechanistically, we found METTL3-mediated m6A modification induced the aberrant expression of LINC02418 in CRC. LINC02418 could interact with YBX1 and enhance YBX1 DNA-binding ability to the CTNNB1 promoter, resulting in transcriptional activation of CTNNB1. In the post-transcriptional stage, LINC02418 could also enhance CTNNB1 stability by promoting the interaction between IGF2BP1 protein and CTNNB1 mRNA. What is more, LINC02418 expression could be transcriptionally enhanced by YBX1 protein. Collectively, this study unveils a novel oncogenic mechanism for LINC02418 in CRC and the LINC02418 might be a novel therapeutic target in CRC treatment.

Circular RNA circCLASP2 promotes nasopharyngeal carcinoma progression through binding to DHX9 to enhance PCMT1 translation

BACKGROUND

Circular RNAs (circRNAs), characterized by their covalently closed-loop structures, constitute a distinct class of non-coding RNAs. They play pivotal regulatory roles within cells and are intricately associated with the progression of malignant tumors. However, their roles and the underlying mechanisms in nasopharyngeal carcinoma (NPC) progression have yet to be fully uncovered and comprehensively understood.

METHODS

Employing RNA sequencing technology, high-abundance circular RNAs in NPC were identified. Expression analysis of circCLASP2 in NPC tissues was conducted using quantitative real-time polymerase chain reaction (qRT-PCR) and in situ hybridization experiments. Through in vitro and in vivo functional assays, the influence of circCLASP2 on the proliferation and metastasis of NPC was investigated. LC-MS/MS technology analyzed the binding partners of circCLASP2, its differentially regulated targets, and the associated proteins of PCMT1. Interactions among circCLASP2, DHX9 protein, and PCMT1 mRNA were elucidated through RNA immunoprecipitation and RNA pull-down techniques. The effects of circCLASP2 and DHX9 on RNA G-quadruplex (rG4) structures and PCMT1 mRNA translation were explored through immunofluorescence (IF), ribosomal gradient separation, and dual-luciferase reporter assays. Immunoprecipitation (IP) revealed the downstream effector of the circCLASP2-DHX9-PCMT1 regulatory axis and Phalloidin staining confirmed its ultimate effect on the cytoskeleton. PDS treatment was applied for interventions in NPC, demonstrating potential therapeutic avenues.

RESULTS

Our research revealed that circCLASP2, a novel circRNA that has not been reported in tumors, is upregulated in NPC and fosters cell proliferation and metastasis both in vitro and in vivo. Mechanistically, circCLASP2 acts as a molecular scaffold, facilitating the approximation of DHX9 to PCMT1 mRNA. DHX9 unwinds the inhibitory rG4 structure near the translation initiation site on PCMT1 mRNA, increasing PCMT1 expression. PCMT1 binds to and upregulates cytoskeleton-associated proteins, modulating cytoskeleton strength and dynamics and ultimately driving NPC cell proliferation and metastasis. In both in vitro and in vivo experiments, PDS significantly inhibits NPC growth and metastasis, showcasing promising therapeutic potential.

CONCLUSIONS

Our investigation pinpointed a circular RNA, circCLASP2, which is upregulated in NPC and augments cytoskeletal functions via the DHX9-PCMT1 axis, contributing to the malignancy progression of NPC. This pathway holds promise as a potential therapeutic target for NPC. Furthermore, these molecules could also serve as biomarkers for adjunct diagnosis and prognosis assessment in NPC.

Hsa_circ_0000105 promotes nasopharyngeal carcinoma malignancy by miR-541-3p/S100A11 axis

OBJECTIVE

This study was to investigate whether hsa_circ_0000105 is involved in the process of regulating Nasopharyngeal Carcinoma (NPC) biological behaviors and to reveal the molecular mechanism.

METHODS

NPC tissues and normal tissues were collected, and NPC cell lines and normal control cell lines were obtained. hsa_circ_0000105/miR-541-3p/S100A11 was evaluated by RT-qPCR or Western blot. CCK-8 assay, EdU assay, Transwell assay, wound healing assay, flow cytometry, and Western blot were employed to evaluate the biological behaviors of NPC cells. Dual luciferase reporter assay and RIP assay were applied to evaluate the direct targeting relationship of hsa_circ_0000105/miR-541-3p/S100A11. A tumor xenotransplantation assay was implemented to evaluate the effect of hsa_circ_0000105 on NPC tumors.

RESULTS

hsa_circ_0000105 and S100A11 were highly expressed in NPC, while miR-541-3p was lowly expressed. hsa_circ_0000105 competitively adsorbed miR-541-3p and mediated S100A11 expression. Silencing or upregulation of hsa_circ_0000105 restricts and induces malignant behavior in HNE2 cells, respectively. The impact of hsa_circ_0000105 silencing on malignant behaviors of HNE2 cells was blocked by miR-541-3p downregulation, while that of hsa_circ_0000105 upregulation was attenuated by S100A11 inhibition.

CONCLUSION

hsa_circ_0000105 acts as a carcinogenic factor in NPC and promotes NPC malignancy by miR-541-3p/S100A11 axis.

Mechanisms and therapeutic implications of gene expression regulation by circRNA-protein interactions in cancer

Circular RNAs (circRNAs) have garnered substantial attention due to their distinctive circular structure and gene regulatory functions, establishing them as a significant class of functional non-coding RNAs in eukaryotes. Studies have demonstrated that circRNAs can interact with RNA-binding proteins (RBPs), which play crucial roles in tumorigenesis, metastasis, and drug response in cancer by influencing gene expression and altering the processes of tumor initiation and progression. This review aims to summarize the recent advances in research on circRNA-protein interactions (CPIs) and discuss the functions and mode of action of CPIs at various stages of gene expression, including transcription, splicing, translation, and post-translational modifications in the context of cancer. Additionally, we explore the role of CPIs in tumor drug resistance to gain a deeper understanding of their potential applications in the development of new anti-cancer therapeutic approaches.

CircRREB1 Mediates Metabolic Reprogramming and Stemness Maintenance to Facilitate Pancreatic Ductal Adenocarcinoma Progression

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal tumor with limited treatment options and poor patient survival. Circular RNAs (circRNA) play crucial regulatory roles in the occurrence and development of various cancers, including PDAC. In this study, using circRNA sequencing of diverse PDAC samples, we identified circRREB1 as an oncogenic circRNA that is significantly upregulated in PDAC and is correlated with an unfavorable patient prognosis. Functionally, loss of circRREB1 markedly inhibited glycolysis and stemness, whereas elevated circRREB1 elicited the opposite effects. Mechanistically, circRREB1 interacted with PGK1, disrupting the association between PTEN and PGK1 and increasing PGK1 phosphorylation to activate glycolytic flux. Moreover, circRREB1 promoted WNT7B transcription by directly interacting with YBX1 and facilitating its nuclear translocation, consequently activating the Wnt/β-catenin signaling pathway to maintain PDAC stemness. Overall, these results highlight circRREB1 as a key regulator of metabolic and stemness properties of PDAC. Significance: CircRREB1 stimulates PGK1 to induce glycolysis and activates the Wnt/β-catenin signaling pathway to maintain stemness in pancreatic cancer, indicating the potential of circRREB1 as a biomarker and therapeutic target.

CircKRT75 augments the cisplatin chemoresistance of nasopharyngeal carcinoma via targeting miR-659/CCAR2 axis

Cisplatin resistance is a clinical challenge limiting the treatment of nasopharyngeal carcinoma (NPC). CircRNAs have been evidenced as key molecules involved in tumor advancement and drug resistance. The present study aimed to elucidate the potential biological value of circKRT75 in NPC cisplatin resistance. CircKRT75 levels in NPC clinical samples and parental/resistant cell lines were analyzed based on qRT-PCR. CCK-8 and flow cytometry were adopted to assess the impacts of circKRT75 on the growth viability and apoptotic ability of NPC resistant cells. Meanwhile, western blot was performed to detect changes in the expression of apoptosis-related proteins. Bioinformatics analysis predicted miRNAs and mRNAs downstream of circKRT75, and the interaction between circKRT75 and downstream targets was validated by RNA pull-down, dual-luciferase reporter and rescue experiments. CircKRT75 was notably enhanced in NPC tissues and NPC cisplatin-resistant cells. Functional experiments disclosed that circKRT75 silencing repressed NPC-resistant cell growth and promoted apoptosis. Bioinformatics screening identified that circKRT75 performed as a molecular sponge for miR-659, and CCAR2 was a direct target of miR-659. Further rescue assays confirmed that miR-659 inhibitor restored the inhibitory effect of circKRT75 knockdown on the growth of drug-resistant cells, while CCAR2 silencing could reverse the promotion of NPC cisplatin resistance by circKRT75 upregulation. Additionally, animal experiments revealed that circKRT75 knockdown restrained NPC cisplatin resistance in vivo. CircKRT75 contributed to cisplatin resistance in NPC through miR-659/CCAR2 signaling, which provided a novel perspective and direction to solve the problem of chemoresistance in NPC.

YB1 and its role in osteosarcoma: a review

YB1 (Y box binding protein 1), a multifunctional protein capable of binding to DNA/RNA, is present in most cells and acts as a splicing factor. It is involved in numerous cellular processes such as transcription, translation, and DNA repair, significantly affecting cell proliferation, differentiation, and apoptosis. Abnormal expression of this protein is closely linked to the formation of various malignancies (osteosarcoma, nasopharyngeal carcinoma, breast cancer, etc.). This review examines the multifaceted functions of YB1 and its critical role in osteosarcoma progression, providing new perspectives for potential therapeutic strategies.

New insights into the potential of exosomal circular RNAs in mediating cancer chemotherapy resistance and their clinical applications

Chemotherapy resistance typically leads to tumour recurrence and is a major obstacle to cancer treatment. Increasing numbers of circular RNAs (circRNAs) have been confirmed to be abnormally expressed in various tumours, where they participate in the malignant progression of tumours, and play important roles in regulating the sensitivity of tumours to chemotherapy drugs. As exosomes mediate intercellular communication, they are rich in circRNAs and exhibit a specific RNA cargo sorting mechanism. By carrying and delivering circRNAs, exosomes can promote the efflux of chemotherapeutic drugs and reduce intracellular drug concentrations in recipient cells, thus affecting the cell cycle, apoptosis, autophagy, angiogenesis, invasion and migration. The mechanisms that affect the phenotype of tumour stem cells, epithelial-mesenchymal transformation and DNA damage repair also mediate chemotherapy resistance in many tumours. Exosomal circRNAs are diagnostic biomarkers and potential therapeutic targets for reversing chemotherapy resistance in tumours. Currently, the rise of new fields, such as machine learning and artificial intelligence, and new technologies such as biosensors, multimolecular diagnostic systems and platforms based on circRNAs, as well as the application of exosome-based vaccines, has provided novel ideas for precision cancer treatment. In this review, the recent progress in understanding how exosomal circRNAs mediate tumour chemotherapy resistance is reviewed, and the potential of exosomal circRNAs in tumour diagnosis, treatment and immune regulation is discussed, providing new ideas for inhibiting tumour chemotherapy resistance.

Extracellular vesicle-packaged PIAT from cancer-associated fibroblasts drives neural remodeling by mediating m5C modification in pancreatic cancer mouse models

Perineural invasion (PNI) is a biological characteristic commonly observed in pancreatic cancer. Although PNI plays a key role in pancreatic cancer metastasis, recurrence, and poor postoperative survival, its mechanism is largely unclarified. Clinical sample analysis and endoscopic ultrasonographic elasticity scoring indicated that cancer-associated fibroblasts (CAFs) were closely related to the occurrence of PNI. Furthermore, CAF-derived extracellular vesicles (EVs) were involved in PNI in dorsal root ganglion coculture and mouse sciatic nerve models. Next, we demonstrated that CAFs promoted PNI through extracellular vesicle transmission of PNI-associated transcript (PIAT). Mechanistically, PIAT specifically bound to YBX1 and blocked the YBX1-Nedd4l interaction to inhibit YBX1 ubiquitination and degradation. Furthermore, PIAT enhanced the binding of YBX1 and PNI-associated mRNAs in a 5-methylcytosine (m5C)-dependent manner. Mutation of m5C recognition motifs in YBX1 or m5C sites in downstream target genes reversed PIAT-mediated PNI. Consistent with these findings, analyses using a KPC mouse model demonstrated that the PIAT/YBX1 axis enhanced PNI through m5C modification. Clinical data suggested that the PIAT expression in the serum EVs of patients with pancreatic cancer was associated with the degree of neural invasion and prognosis. Our study revealed the important role of the PIAT/YBX1 signaling axis in the tumor microenvironment (TME) in promoting tumor cell PNI and provided a new target for precise interference with CAFs and RNA methylation in the TME to suppress PNI in pancreatic cancer.

SETD8 inhibits apoptosis and ferroptosis of Ewing's sarcoma through YBX1/RAC3 axis

Ewing's sarcoma (ES) represents a rare yet exceedingly aggressive neoplasm that poses a significant health risk to the pediatric and adolescent population. The clinical outcomes for individuals with relapsed or refractory ES are notably adverse, primarily attributed to the constrained therapeutic alternatives available. Despite significant advancements in the field, molecular pathology-driven therapeutic strategies have yet to achieve a definitive reduction in the mortality rates associated with ES. Consequently, there exists an imperative need to discover innovative therapeutic targets to effectively combat ES. To reveal the mechanism of the SETD8 (also known as lysine methyltransferase 5A) inhibitor UNC0379, cell death manners were analyzed with different inhibitors. The contributions of SETD8 to the processes of apoptosis and ferroptosis in ES cells were evaluated employing the histone methyltransferase inhibitor UNC0379 in conjunction with RNA interference techniques. The molecular regulatory mechanisms of SETD8 in ES were examined through the application of RNA sequencing (RNA-seq) and mass spectrometry-based proteomic analysis. Moreover, nude mouse xenograft models were established to explore the role of SETD8 in ES in vivo. SETD8, a sole nucleosome-specific methyltransferase that catalyzes mono-methylation of histone H4 at lysine 20 (H4K20me1), was found to be upregulated in ES, and its overexpression was associated with dismal outcomes of patients. SETD8 knockdown dramatically induced the apoptosis and ferroptosis of ES cells in vitro and suppressed tumorigenesis in vivo. Mechanistic investigations revealed that SETD8 facilitated the nuclear translocation of YBX1 through post-transcriptional regulatory mechanisms, which subsequently culminated in the transcriptional upregulation of RAC3. In summary, SETD8 inhibits the apoptosis and ferroptosis of ES cells through the YBX1/RAC3 axis, which provides new insights into the mechanism of tumorigenesis of ES. SETD8 may be a potential target for clinical intervention in ES patients.

PJA1-mediated suppression of pyroptosis as a driver of docetaxel resistance in nasopharyngeal carcinoma

Chemoresistance is a main reason for treatment failure in patients with nasopharyngeal carcinoma, but the exact regulatory mechanism underlying chemoresistance in nasopharyngeal carcinoma remains to be elucidated. Here, we identify PJA1 as a key E3 ubiquitin ligase involved in nasopharyngeal carcinoma chemoresistance that is highly expressed in nasopharyngeal carcinoma patients with nonresponse to docetaxel-cisplatin-5-fluorouracil induction chemotherapy. We find that PJA1 facilitates docetaxel resistance by inhibiting GSDME-mediated pyroptosis in nasopharyngeal carcinoma cells. Mechanistically, PJA1 promotes the degradation of the mitochondrial protein PGAM5 by increasing its K48-linked ubiquitination at K88, which further facilitates DRP1 phosphorylation at S637 and reduced mitochondrial reactive oxygen species production, resulting in suppression of GSDME-mediated pyroptosis and the antitumour immune response. PGAM5 knockdown fully restores the docetaxel sensitization effect of PJA1 knockdown. Moreover, pharmacological targeting of PJA1 with the small molecule inhibitor RTA402 enhances the docetaxel sensitivity of nasopharyngeal carcinoma in vitro and in vivo. Clinically, high PJA1 expression indicates inferior survival and poor clinical efficacy of TPF IC in nasopharyngeal carcinoma patients. Our study emphasizes the essential role of E3 ligases in regulating chemoresistance and provides therapeutic strategies for nasopharyngeal carcinoma based on targeting the ubiquitin-proteasome system.

Emerging roles of circular RNAs in nasopharyngeal carcinoma: functions and implications

Nasopharyngeal carcinoma (NPC) is a distinct malignancy primarily prevalent in Southern China and Southeast Asia. Circular RNAs (circRNAs), a class of non-coding RNAs, are evolutionarily conserved and exhibit remarkable stability. Their dysregulation has been observed in various cancers, including NPC. In this review, we investigate the pivotal role of circRNAs in NPC, focusing specifically on their involvement in tumor proliferation, apoptosis, metastasis, angiogenesis, stemness, metabolism, and the tumor microenvironment. We highlight the diagnostic and prognostic potential of circRNAs in NPC, emphasizing their utility as biomarkers for early detection, disease monitoring, and prediction of treatment outcomes. Additionally, we explore the therapeutic implications of circRNAs in NPC, highlighting their potential for targeted therapies.

The GFPT2-O-GlcNAcylation-YBX1 axis promotes IL-18 secretion to regulate the tumor immune microenvironment in pancreatic cancer

The immunosuppressive microenvironment caused by several intrinsic and extrinsic mechanism has brought great challenges to the immunotherapy of pancreatic cancer. We identified GFPT2, the key enzyme in hexosamine biosynthesis pathway (HBP), as an immune-related prognostic gene in pancreatic cancer using transcriptome sequencing and further confirmed that GFPT2 promoted macrophage M2 polarization and malignant phenotype of pancreatic cancer. HBP is a glucose metabolism pathway leading to the generation of uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), which is further utilized for protein O-GlcNAcylation. We confirmed GFPT2-mediated O-GlcNAcylation played an important role in regulating immune microenvironment. Through cellular proteomics, we identified IL-18 as a key downstream of GFPT2 in regulating the immune microenvironment. Through CO-IP and protein mass spectrum, we confirmed that YBX1 was O-GlcNAcylated and nuclear translocated by GFPT2-mediated O-GlcNAcylation. Then, YBX1 functioned as a transcription factor to promote IL-18 transcription. Our study elucidated the relationship between the metabolic pathway of HBP in cancer cells and the immune microenvironment, which might provide some insights into the combination therapy of HBP vulnerability and immunotherapy in pancreatic cancer.

Single-cell transcriptome analysis reveals the association between histone lactylation and cisplatin resistance in bladder cancer

Patients with bladder cancer (BCa) frequently acquires resistance to platinum-based chemotherapy, particularly cisplatin. This study centered on the mechanism of cisplatin resistance in BCa and highlighted the pivotal role of lactylation in driving this phenomenon. Utilizing single-cell RNA sequencing, we delineated the single-cell landscape of Bca, pinpointing a distinctive subset of BCa cells that exhibit marked resistance to cisplatin with association with glycolysis metabolism. Notably, we observed that H3 lysine 18 lactylation (H3K18la) plays a crucial role in activating the transcription of target genes by enriching in their promoter regions. Targeted inhibition of H3K18la effectively restored cisplatin sensitivity in these cisplatin-resistant epithelial cells. Furthermore, H3K18la-driven key transcription factors YBX1 and YY1 promote cisplatin resistance in BCa. These findings enhance our understanding of the mechanisms underlying cisplatin resistance, offering valuable insights for identifying novel intervention targets to overcome drug resistance in Bca.

Overcoming chemoresistance and radio resistance in prostate cancer: The emergent role of non-coding RNAs

Prostate cancer (PCa) continues to be a major health concern worldwide, with its resistance to chemotherapy and radiation therapy presenting major hurdles in successful treatment. While patients with localized prostate cancer generally have a good survival rate, those with metastatic prostate cancer often face a grim prognosis, even with aggressive treatments using various methods. The high mortality rate in severe cases is largely due to the lack of treatment options that can offer lasting results, especially considering the significant genetic diversity found in tumors at the genomic level. This comprehensive review examines the intricate molecular mechanisms governing resistance in PCa, emphasising the pivotal contributions of non-coding RNAs (ncRNAs). We delve into the diverse roles of microRNAs, long ncRNAs, and other non-coding elements as critical regulators of key cellular processes involved in CR & RR. The review emphasizes the diagnostic potential of ncRNAs as predictive biomarkers for treatment response, offering insights into patient stratification and personalized therapeutic approaches. Additionally, we explore the therapeutic implications of targeting ncRNAs to overcome CR & RR, highlighting innovative strategies to restore treatment sensitivity. By synthesizing current knowledge, this review not only provides a comprehension of the chemical basis of resistance in PCa but also identifies gaps in knowledge, paving the way for future research directions. Ultimately, this exploration of ncRNA perspectives offers a roadmap for advancing precision medicine in PCa, potentially transforming therapeutic paradigms and improving outcomes for patients facing the challenges of treatment resistance.

Hsa_circ_0007990 promotes breast cancer growth via inhibiting YBX1 protein degradation to activate E2F1 transcription

Breast cancer (BC) is the most commonly diagnosed malignant tumour in females worldwide. Although remarkable advances in early detection and treatment strategies have led to decreased mortality, recurrence and metastasis remain the major causes of cancer death in BC patients. Increasing evidence has demonstrated that circular RNAs (circRNAs) play critical roles in cancer progression. However, the detailed biological functions and molecular mechanisms of circRNAs in BC are unclear. The aim of this study was to investigate the possible role of circRNAs in the progression of BC. Differentially expressed circRNAs in BC were identified by integrating breast tumour-associated somatic CNV data and circRNA high-throughput sequencing. Aberrant hsa_circ_0007990 expression and host gene copy number were detected in BC cell lines via quantitative polymerase chain reaction (qPCR). The expression level of hsa_circ_0007990 in BC tissues was validated by in situ hybridization (ISH). Loss- and gain-of-function experiments were performed in vitro and in vivo, respectively, to explore the potential biological function of hsa_circ_0007990 in BC. The underlying mechanisms of hsa_circ_0007990 were investigated through MS2 RNA pull-down, RNA immunoprecipitation, RNA fluorescence in situ hybridization, immunofluorescence, chromatin immunoprecipitation and luciferase reporter assays. The levels of hsa_circ_0007990 were elevated in BC tissues and cell lines, an effect that was partly due to host gene copy number gains. Functional assays showed that hsa_circ_0007990 promoted BC cell growth. Mechanistically, hsa_circ_0007990 could bind to YBX1 and inhibit its degradation by preventing ubiquitin/proteasome-dependent degradation, thus enhancing the expression of the cell cycle-associated gene E2F1. Rescue experiments suggested that hsa_circ_0007990 promoted BC progression through YBX1. In general, our study demonstrated that hsa_circ_0007990 modulates the ubiquitination and degradation of YBX1 protein and further regulates E2F1 expression to promote BC progression. We explored the possible function and molecular mechanism of hsa_circ_0007990 in BC and identified a novel candidate target for the treatment of BC.

CircRAD23B promotes proliferation and carboplatin resistance in ovarian cancer cell lines and organoids

BACKGROUND

Circular RNAs (circRNAs) are involved in the regulation of progression and drug resistance in ovarian cancer (OC). In the present study, we aimed to explore the role of circRAD23B, a newly identified circRNA, in the regulation of carboplatin-resistant OC.

METHODS

CircRAD23B expression levels were measured using qRT-PCR. The biological roles of circRAD23B were analysed using CCK-8, colony formation, EDU, flow cytometry, and cell viability assays. RNA pull-down and luciferase assays were used to investigate the interactions of circRAD23B with mRNAs and miRNAs.

RESULTS

CircRAD23B was significantly increased in carboplatin-resistant OC tissues. CircRAD23B promoted proliferation and reduced sensitivity to carboplatin in cell lines and patient-derived organoids (PDOs), consistent with in vivo findings. Mechanistically, circRAD23B acted as a molecular sponge, abrogating its inhibitory effect on Y-box binding protein 1 (YBX1) by adsorbing miR-1287-5p. Rescue experiments confirmed that the pro-proliferation and carboplatin resistance mediated by circRAD23B was partially reversed by the upregulation of miR-1287-5p.

CONCLUSIONS

Our results demonstrated, for the first time, the role of the circRAD23B/miR-1287-5p/YBX1 axis in OC progression and carboplatin resistance in cell lines, PDOs, and animal models, providing a basis for the development of targeted therapies for patients with OC.

Y-Box Binding Protein 1: Unraveling the Multifaceted Role in Cancer Development and Therapeutic Potential

Y-box binding protein 1 (YBX1), a member of the Cold Shock Domain protein family, is overexpressed in various human cancers and is recognized as an oncogenic gene associated with poor prognosis. YBX1's functional diversity arises from its capacity to interact with a broad range of DNA and RNA molecules, implicating its involvement in diverse cellular processes. Independent investigations have unveiled specific facets of YBX1's contribution to cancer development. This comprehensive review elucidates YBX1's multifaceted role in cancer across cancer hallmarks, both in cancer cell itself and the tumor microenvironment. Based on this, we proposed YBX1 as a potential target for cancer treatment. Notably, ongoing clinical trials addressing YBX1 as a target in breast cancer and lung cancer have showcased its promise for cancer therapy. The ramp up in in vitro research on targeting YBX1 compounds also underscores its growing appeal. Moreover, the emerging role of YBX1 as a neural input is also proposed where the high level of YBX1 was strongly associated with nerve cancer and neurodegenerative diseases. This review also summarized the up-to-date advanced research on the involvement of YBX1 in pancreatic cancer.

The functions and mechanisms of post-translational modification in protein regulators of RNA methylation: Current status and future perspectives

RNA methylation, an epigenetic modification that does not alter gene sequence, may be important to diverse biological processes. Protein regulators of RNA methylation include "writers," "erasers," and "readers," which respectively deposit, remove, and recognize methylated RNA. RNA methylation, particularly N6-methyladenosine (m6A), 5-methylcytosine (m5C), N3-methylcytosine (m3C), N1-methyladenosine (m1A) and N7-methylguanosine (m7G), has been suggested as disease therapeutic targets. Despite advances in the structure and pharmacology of RNA methylation regulators that have improved drug discovery, regulating these proteins by various post-translational modifications (PTMs) has received little attention. PTM modifies protein structure and function, affecting all aspects of normal biology and pathogenesis, including immunology, cell differentiation, DNA damage repair, and tumors. It is becoming evident that RNA methylation regulators are also regulated by diverse PTMs. PTM of RNA methylation regulators induces their covalent linkage to new functional groups, hence modifying their activity and function. Mass spectrometry has identified many PTMs on protein regulators of RNA methylation. In this review, we describe the functions and PTM of protein regulators of RNA methylation and summarize the recent advances in the regulatory mode of human disease and its underlying mechanisms.

circPSD3 is a promising inhibitor of uPA system to inhibit vascular invasion and metastasis in hepatocellular carcinoma

BACKGROUND

Vascular invasion is a major route for intrahepatic and distant metastasis in hepatocellular carcinoma (HCC) and is a strong negative prognostic factor. Circular RNAs (circRNAs) play important roles in tumorigenesis and metastasis. However, the regulatory functions and underlying mechanisms of circRNAs in the development of vascular invasion in HCC are largely unknown.

METHODS

High throughput sequencing was used to screen dysregulated circRNAs in portal vein tumor thrombosis (PVTT) tissues. The biological functions of candidate circRNAs in the migration, vascular invasion, and metastasis of HCC cells were examined in vitro and in vivo. To explore the underlying mechanisms, RNA sequencing, MS2-tagged RNA affinity purification, mass spectrometry, and RNA immunoprecipitation assays were performed.

RESULTS

circRNA sequencing followed by quantitative real-time PCR (qRT-PCR) revealed that circRNA pleckstrin and Sect. 7 domain containing 3 (circPSD3) was significantly downregulated in PVTT tissues. Decreased circPSD3 expression in HCC tissues was associated with unfavourable characteristics and predicted poor prognosis in HCC. TAR DNA-binding protein 43 (TDP43) inhibited the biogenesis of circPSD3 by interacting with the downstream intron of pre-PSD3. circPSD3 inhibited the intrahepatic vascular invasion and metastasis of HCC cells in vitro and in vivo. Serpin family B member 2 (SERPINB2), an endogenous bona fide inhibitor of the urokinase-type plasminogen activator (uPA) system, is the downstream target of circPSD3. Mechanistically, circPSD3 interacts with histone deacetylase 1 (HDAC1) to sequester it in the cytoplasm, attenuating the inhibitory effect of HDAC1 on the transcription of SERPINB2. In vitro and in vivo studies demonstrated that circPSD3 is a promising inhibitor of the uPA system.

CONCLUSIONS

circPSD3 is an essential regulator of vascular invasion and metastasis in HCC and may serve as a prognostic biomarker and therapeutic target.

Autophagy and cancer drug resistance in dialogue: Pre-clinical and clinical evidence

The emergence of drug resistance is a major challenge for oncologists. Resistance can be categorized as acquired or intrinsic; the alteration of several biological mechanisms contributes to both intrinsic and acquired resistance. Macroautophagy/autophagy is the primary process in eukaryotes for the degradation of macromolecules and organelles. This process is critical in maintaining cellular homeostasis. Given its function as either a pro-survival or a pro-death phenomenon, autophagy has a complex physio-pathological role. In some circumstances, autophagy can confer chemoresistance and promote cell survival, whereas in others it can promote chemosensitivity and contribute to cell death. The role of autophagy in the modulation of cancer drug resistance reflects its impact on apoptosis and metastasis. The regulation of autophagy in cancer is mediated by various factors including AMP-activated protein kinase (AMPK), MAPK, phosphoinositide 3-kinase (PI3K)-AKT, BECN1 and ATG proteins. Non-coding RNAs are among the main regulators of autophagy, e.g., via the modulation of chemoresistance pathways. Due to the significant contribution of autophagy in cancer drug resistance, small molecule modulators and natural compounds targeting autophagy have been introduced to alter the response of cancer cells to chemotherapy. Furthermore, nanotherapeutic approaches based on autophagy regulation have been introduced in pre-clinical cancer therapy. In this review we consider the potential for using autophagy regulators for the clinical treatment of malignancies.

Exosomal circular RNAs: A chief culprit in cancer chemotherapy resistance

Chemotherapy is one of the primary treatments for malignant tumors. However, the acquired drug resistance hinders clinical efficacy and leads to treatment failure in most patients. Exosomes are cell-derived vesicles with a diameter of 30-150 nm carrying and delivering substances such as DNAs, RNAs, lipids, and proteins for cellular communication in tumor development. Circular RNAs (circRNAs) present covalently closed-loop RNA structures, which regulate tumor cell proliferation, apoptosis, and metastasis by controlling different genes and signaling pathways. CircRNAs are abundant and stably expressed in exosomes. Recent studies have shown that they play critical roles in chemotherapy resistance in various cancers. In this review, we summarized the origin of exosomes and discussed the regulation mechanism of exosomal circRNAs in cancer drug resistance.

circRNF10 Regulates Tumorigenic Properties and Natural Killer Cell-Mediated Cytotoxicity against Breast Cancer through the miR-934/PTEN/PI3k-Akt Axis

Circular RNA (circRNA), a type of non-coding RNA, has received a great deal of attention with regard to the initiation and progression of tumors. However, the molecular mechanism and function of circRNAs in breast cancer (BC) remain unclear. In the current study, we discovered that hsa_circ_0028899 (also called circRNF10) was significantly reduced in BC tissues, and a higher level of circRNF10 was markedly related to a favorable prognosis. The results of CCK8, colony formation, Transwell, ELISA, and NK cell-mediated cytotoxicity assays indicated that increased circRNF10 expression could significantly repress the proliferation, invasion, and migration of BC cells and enhance the killing efficiency of NK cells against BC cells. According to these biological functions, the possible role and molecular mechanism of circRNF10 in BC cells were further investigated. We used bioinformatics prediction tools to predict circRNF10-bound miRNAs, which were verified by many experimental studies, including FISH, luciferase reporter assays, RIP, and Western blots. These data suggest that circRNF10 serves as a molecular sponge for miR-934 to further regulate PTEN expression and PI3k/Akt/MICA signaling in vitro and tumor growth in vivo. Altogether, these findings reveal that circRNF10 functions as a novel anti-oncogene in BC via sponging miR-934 and suppressing the PI3K/Akt/MICA pathway.