Stabilization of IGF2BP1 by USP10 promotes breast cancer metastasis via CPT1A in an m6A-dependent manner

The RNA-Binding Proteins MCPIP2 and IGF2BP1 Competitively Modulate Breast Tumor Angiogenesis by Antagonizing VEGFA mRNA Stability and Expression

Tumor angiogenesis is essential for further growth and metastasis of solid tumors. However, the mechanisms underlying angiogenesis-related gene expression have yet to be clarified. Here, we discovered RNA-binding proteins monocyte chemotactic protein-induced protein 2 (MCPIP2) and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) function as a pair of antagonists that modulate breast tumor angiogenesis by competitively regulating mRNA stability of proangiogenic gene transcripts, including vascular endothelial growth factor A (VEGFA), Erb-B2 receptor tyrosine kinase 2 (ERBB2), interleukin-8 (IL8), C-X-C motif chemokine ligand 1 (CXCL1), and ephrin A1 (EFNA1). Mechanistically, MCPIP2 physically interacted with the stem-loop structures in the 3'-untranslated region of proangiogenic transcripts through its RNase domain to destabilize their mRNAs. Ribosomal proteins might be required for MCPIP2-mediated destabilization of proangiogenic mRNAs. On the other hand, IGF2BP1 can stabilize the proangiogenic mRNAs by binding to the common RNA stem-loop structures. Furthermore, we found that MCPIP2 expression in human breast tumors was repressed, whereas IGF2BP1 expression increased. Lower MCPIP2 expression and higher IGF2BP1 expression in human breast tumors were significantly associated with poor survival of breast cancer patients, respectively. Notably, there was a reversed correlation relationship between MCPIP2, IGF2BP1 expression, and proangiogenic gene expression in human breast tumor samples. Collectively, our results elucidate a novel mechanism by which MCPIP2 and IGF2BP1 competitively modulate the expression of proangiogenic transcripts, which provides new insights into antiangiogenic therapy of breast cancer.

Role of ubiquitin-specific proteases in programmed cell death of breast cancer cells

Breast cancer (BC) is the most common malignant tumor and the leading cause of cancer-related deaths among women worldwide. Great progress has been recently achieved in controlling breast cancer; however, mortality from breast cancer remains a substantial challenge, and new treatment mechanisms are being actively sought. Programmed cell death (PCD) is associated with the progression and treatment of many types of human cancers. PCD can be divided into multiple pathways including autophagy, apoptosis, mitotic catastrophe, necroptosis, ferroptosis, pyroptosis, and anoikis. Ubiquitination is a post-translational modification process in which ubiquitin, a 76-amino acid protein, is coupled to the lysine residues of other proteins. Ubiquitination is involved in many physiological events and promotes cancer development and progression. This review elaborates the role of ubiquitin-specific protease (USP) in programmed cell death, which is common in breast cancer cells, and lays the foundation for tumor diagnosis and targeted therapy.

METTL3/IGF2BP1 promotes the development of triple-negative breast cancer by mediating m6A methylation modification of PRMT7

BACKGROUND

PRMT7 is upregulated in breast cancer and promotes tumor metastasis. Here we aimed to explore the function and mechanism of PRMT7 in triple-negative breast cancer (TNBC).

METHODS

The expression of PRMT7, METTL3 and IGF2BP1 was detected by immunohistochemistry (IHC), qRT-PCR and western blot. Cell viability and proliferation were measured using MTT and EdU assay. Flow cytometry and TUNEL assays were used to evaluate apoptosis. Invasion and migration were assessed by transwell and wound healing assays, respectively. Glucose consumption and lactate production were measured to assess glycolysis. In addition, the interaction between METTL3 and PRMT was verified by methylated RNA immunoprecipitation. The roles of METTL3 and PRMT in vivo were investigated through a xenograft model.

RESULTS

PRMT7 was upregulated in TNBC tissues and cells, and the knockdown of PRMT7 inhibited cell proliferation, invasion, migration and glycolysis, but induced apoptosis in TNBC cells. METTL3/IGF2BP1 enhanced PRMT7 expression by mediating the m6A methylation modification of PRMT7. Besides, METTL3 knockdown suppressed the progression of TNBC cells and regulated the WNT/β-catenin pathway via PRMT7. Moreover, silencing METTL3 restrained TNBC tumor growth in vivo through regulating PRMT7.

CONCLUSION

METTL3/IGF2BP1 facilitates the progression of TNBC by mediating m6A methylation modification of PRMT7.

Replication factor C4, which is regulated by insulin-like growth factor 2 mRNA binding protein 2, enhances the radioresistance of breast cancer by promoting the stemness of tumor cells

Radiotherapy resistance, is usually caused by enhanced tumor stemness and poses a significant challenge in treating breast cancer (BRCA). In this study, we investigated the molecular regulatory mechanism of radiotherapy sensitivity in BRCA associated with replication factor C4 (RFC4) and insulin-like growth factor 2 mRNA binding protein 2 mRNA Binding Protein 2 (IGF2BP2). RFC4 expression was increased in BRCA cell lines and tissues, and high RFC4 expression in BRCA patients predicted the occurrence of lymphatic metastasis. RFC4-specific short hairpin RNA sequences or RFC4 coding sequences were subsequently cloned and inserted into plasmid vectors to downregulate or upregulate RFC4 expression. Knockdown of RFC4 attenuated stemness, as evidenced by a reduction in sphere formation and the downregulation of CD44 and SOX2. RFC4 silencing inhibited migration and invasion, promoted apoptosis, and improved sensitivity to radiotherapy (4-Gy X-ray). The results were detected by a wound healing assay, a transwell assay, and flow cytometry. The overexpression of RFC4 had the opposite effect on BRCA cells. Like RFC4 expression, IGF2BP2 expression was also increased in the cancer tissues of breast cancer patients. The results of the dual luciferase assay and RIP assay confirmed the binding of IGF2BP2 to the RFC4 mRNA coding sequence. Knockdown of RFC4 eliminated the effects of IGF2BP2 overexpression on increasing cell viability, invasion, the expression of stemness markers and radioresistance, suggesting that the effect of RFC4 on the stemness of BRCA cells was regulated by IGF2BP2. In conclusion, we reported that RFC4, a key regulator of BRCA progression, promoted radioresistance in BRCA and was positively regulated by IGF2BP2.

CPT1A Alleviates Senescence and Restores Osteogenic Differentiation of BM-MSC Through SOD2 Succinylation

Bone marrow mesenchymal stem cells (BM-MSCs) have promising prospects in bone repair and regenerative medicine. However, BM-MSCs gradually lose their original pluripotency and differentiation potential after successive passages. This study aimed to reveal the mechanism underlying the phenomenon. Western blotting, SA-β-gal staining and Alizarin red staining were used to evaluate the senescence phenotype and osteogenic differentiation ability. Mitochondrial ROS levels were detected using flow cytometry. Protein interactions and succinylation modifications were identified by using Co-IP assays. With the increase in passage times, the proliferation and osteogenic differentiation of BM-MSCs were gradually weakened, and the expression level of CPT1A was decreased. BM-MSCs with fewer passages (P1-P5 generations) showed increased mitochondrial ROS production and reduced enzyme activity of superoxide dismutase 2 (SOD2) and the mitochondrial level after the knockdown of CPT1A. In contrast, overexpression of CPT1A in multiple-round-passed BM-MSCs cells (P10-P15 generations) has the opposite effect. Therefore, CPT1A level is associated with the ageing phenotypes and the osteogenic differentiation capacity of BM-MSCs. Knocking down CPT1A significantly reduced the succinylation modification of SOD2, resulting in a decrease in SOD2 enzyme activity and SOD2 levels in mitochondria. Overexpression of CPT1A enhanced the succinylation of SOD2 at the key site K130, thereby reducing cell senescence and promoting osteogenic differentiation. However, this boosting effect was reversed when a mutation occurred at the K130 site of SOD2. CPT1A promotes succinylation modification at the SOD2 (K130) site to induce the accumulation of SOD2 in mitochondria and the enzyme activity, which alleviates BM-MSC senescence and enhances osteogenic differentiation.

Research progress on N6-Methyladenosine modification in angiogenesis, vasculogenic mimicry, and therapeutic implications in breast cancer

N6-methyladenosine (m6A) modification is the most common epitranscriptomic modification in eukaryotic RNA and has garnered extensive attention in the context of breast cancer research. The m6A modification significantly impacts tumorigenesis and tumor progression by regulating RNA stability, splicing, translation, and degradation. In this review we summarize recent advances in understanding the roles of m6A modification in the mechanisms underlying angiogenesis and vasculogenic mimicry in breast cancer. We review how m6A modification and associated transcripts influence relevant factors by affecting key factors and signaling pathways, highlighting the interactions among m6A "writers," "erasers," and "readers," and their overall impact on tumor angiogenesis and vasculogenic mimicry, as well as potential new therapeutic targets.

Exploring m6A modifications in gastric cancer: from molecular mechanisms to clinical applications

The significance of m6A modifications in several biological processes has been increasingly recognized, particularly in the context of cancer. For instance, m6A modifications in gastric cancer (GC) have been significantly implicated in tumor progression, metastasis, and treatment resistance. GC is characterized by the differential expression of m6A regulators. High expression writers such as METTL3 and WTAP are associated with poor prognosis and aggressive clinical features. Conversely, low expression of METTL14 is linked to worse clinical outcomes, whereas elevated levels of demethylases, such as FTO and ALKBH5, correlate with better survival rates. These m6A regulators influence several cellular biological functions, including proliferation, invasion, migration, glycolysis, and chemotherapy resistance, thereby affecting tumor growth and therapeutic outcomes. The assessment of m6A modification patterns and the expression profiles of m6A-related genes hold substantial potential for improving the clinical diagnosis and treatment of GC. In this review, we provide an updated and comprehensive summary of the role of m6A modifications in GC, emphasizing their molecular mechanisms, clinical significance, and translational applications in developing novel diagnostic and therapeutic strategies.

RBM15 facilitates osimertinib resistance of lung adenocarcinoma through m6A-dependent epigenetic silencing of SPOCK1

Lung cancer is the leading cause of cancer-related mortality globally. N6-methyladenosine (m6A) is the most abundant modification in mammalian mRNA and is involved in the biological regulation of tumors, including lung cancer. However, the role of m6A-related proteins, such as RNA-binding motif protein 15 (RBM15), in lung cancer progression remains largely unknown. Our study indicated that RBM15 is significantly overexpressed in lung adenocarcinoma, serving as an independent prognostic factor for poor outcomes and facilitating tumor cell proliferation and migration. RBM15 was markedly elevated in patients with EGFR mutations, correlating with a poorer prognosis, while it had negligible prognostic value in EGFR wild-type patients. As EGFR-tyrosine kinase inhibitors (TKIs) are the standard treatment for patients with EGFR mutations, we subsequently determined that RBM15 drives osimertinib resistance via a novel mechanism: enhancing m6A modification of cwcv- and kazal-like domains proteoglycan 1 (SPOCK1) mRNA, promoting epithelial-mesenchymal transition-mediated osimertinib resistance through a bypass activation pathway. These findings were validated in osimertinib-resistant H1975 cells and organoids from patients with osimertinib-resistant lung adenocarcinoma. Furthermore, the RBM15-SPOCK1 axis was activated in drug-tolerant persister cells, indicating that early targeting of RBM15 during EGFR-TKI treatment could dramatically extend the patient response and benefit from TKI therapy. Our results emphasize the critical role of RBM15 in reversing EGFR-TKI resistance and propose it as a promising therapeutic target for prolonging TKI treatment benefits in patients with lung adenocarcinoma.

MARCHF1 promotes breast cancer through accelerating REST ubiquitylation and following TFAM transcription

Breast cancer has become the leading cause of death in women. Membrane associated ring-CH-type finger 1 (MARCHF1) is associated with the development of various types of cancer, but the exact role of MARCHF1 in breast cancer remains unclear. In our study, the higher MARCHF1 expression was observed in tumor samples of patients with breast cancer and then the role of MARCHF1 in breast cancer was further evaluated. Overexpression of MARCHF1 contributed to proliferation of cancer cells and inhibition of oxidative stress. Knockdown of MARCHF1 reduced breast cancer cell proliferation, increased mitochondrial dysfunction induced by oxidative stress, eventually aggravating cell death. In vivo, MARCHF1 promoted the tumor growth and oppositely, MARCHF1 silencing suppressed the tumor development. Moreover, MARCHF1 interacted with repressor Element-1 silencing transcription factor (REST) and facilitated its ubiquitylation and degradation. Subsequently, REST negatively regulated the transcription of mitochondrial transcription factor A (TFAM). The subcutaneous tumor formation assay in nude mice also supported these conclusions. In details, knockdown of MARCHF1 upregulated the protein expression of REST and downregulated the mRNA level of TFAM. On the contrary, MARCHF1 overexpression exhibited opposite effects. Thus, MARCHF1 is conducive to the progression of breast cancer via promoting the ubiquitylation and degradation of RSET and then the transcription of TFAM. Downregulating MARCHF1 could provide a novel direction for treating breast cancer.

LINC00882, transcriptionally activated by CEBP-β and post-transcriptionally stabilized by METTL14-mediated m6A modification, exerts tumorigenesis by promoting PABPC1-mediated stabilization of ELK3 mRNA

Breast cancer (BC) is the most common malignant tumor in women, and the majority of BC-related deaths are due to tumor metastasis. There is emerging evidence for the role of long noncoding RNAs (lncRNAs) in tumor progression. Nevertheless, lncRNAs that drive metastasis in patients with BC and the underlying mechanisms of lncRNAs are still largely elusive. In this study, we showed that LINC00882 was highly expressed in metastatic BC tissues, and a receiver operating characteristic (ROC) curve was able to distinguish well between BC cases with lymph node metastasis (LNM) and those without LNM. Functionally, LINC00882 promoted BC invasion and metastasis in vitro and in vivo. Mechanistically, at the transcriptional level, CEBP-β could bind directly to the LINC00882 promoter region and activate its transcription. Moreover, at the posttranscriptional level, m6A modification of LINC00882 mediated by methyltransferase-like 14 (METTL14) promoted its expression via an IGF2BP2-dependent pathway. Furthermore, 514-615 nucleotides of LINC00882 could directly interact with poly (A) binding protein cytoplasmic 1 (PABPC1) and promote the interaction between PABPC1 and ELK3 mRNA, thereby stabilizing ELK3 mRNA and enhancing the ELK3 protein level. E-cadherin expression was suppressed via ELK3-mediated transcription inhibition, subsequently activating epithelial-mesenchymal transition to promote BC metastasis. These results highlight the role of LINC00882 in BC, and LINC00882 may be a diagnostic and therapeutic target for BC.

Glucose homeostasis controls N-acetyltransferase 10-mediated ac4C modification of HK2 to drive gastric tumorigenesis

Rationale: Abnormal metabolic states contribute to a variety of diseases, including cancer. RNA modifications have diverse biological functions and are implicated in cancer development, including gastric cancer (GC). However, the direct relationship between glucose homeostasis and 4-acetylcytosine (ac4C) modification in GC remains unclear. Methods: The prognostic value of RNA acetyltransferase NAT10 expression was evaluated in a human GC cohort. Additionally, preoperative PET/CT data from GC patients and Micro-PET/CT imaging of mice were employed to assess the relationship between NAT10 and glucose metabolism. The biological role of NAT10 in GC was investigated through various experiments, including GC xenografts, organoids, and a conditional knockout (cKO) mouse model. The underlying mechanisms were examined using dot blotting, immunofluorescence staining, co-immunoprecipitation, and high-throughput sequencing, among other techniques. Results: Glucose deprivation activates the autophagy-lysosome pathway, leading to the degradation of NAT10 by enhancing its interaction with the sequestosome 1 (SQSTM1)/microtubule-associated protein 1 light chain 3 alpha (LC3) complex, ultimately resulting in a reduction of ac4C modification. Furthermore, the levels of ac4C and NAT10 are elevated in GC tissues and correlate with poor prognosis. A strong correlation exists between NAT10 levels and 18F-FDG uptake in GC patients. Furthermore, NAT10 drives glycolytic metabolism and gastric carcinogenesis in vitro and in vivo. Mechanistically, NAT10 stimulates ac4C modification at the intersection of the coding sequence (CDS) and 3' untranslated region (3'UTR) of hexokinase 2 (HK2) mRNA, enhancing its stability and activating the glycolytic pathway, thereby driving gastric tumorigenesis. Conclusion: Our findings highlight the critical crosstalk between glucose homeostasis and the ac4C epitranscriptome in gastric carcinogenesis. This finding offers a potential strategy of targeting NAT10/HK2 axis for the treatment of GC patients, especially those with highly active glucose metabolism.

Ferroptosis related CPT1A and GDF15 gene polymorphisms are risk factors for lung adenocarcinoma: A case-control study

BACKGROUND

Ferroptosis is not only a consequence of inflammation, but also a dynamic process. Recent bioinformatics analysis suggests that ferroptosis related genes might be associated with lung adenocarcinoma (LUAD). CPT1A and GDF15 are critical for the process of ferroptosis and development of inflammation; however, little study focused on the mutation level of these genes in patients with LUAD.

METHODS

The candidate SNPs in CPT1A and GDF15 were genotyped in 320 pairs of LUAD patients and controls using Mass ARRAY platform. Moreover, the different expression of CPT1A and GDF15 in LUAD cases and healthy controls were validated by qRT-PCR and ELISA.

RESULTS

The rs80356779 G > A, rs3019594 C > T, rs888663 T > G and rs4808793 G > C all exhibited an increased risk of the disease (p < 0.05). Moreover, the rs80356779-GA, rs3019594-TT, rs888663-TG and rs4808793-CC genotypes were all related to different levels of increase in LUAD risk (p < 0.05). Genetic model results showed that rs80356779 G > A, rs888663 T > G and rs4808793 G > C were associated with LUAD susceptibility under dominant and additive models (p < 0.05), while rs3019594 C > T was correlated with an elevated risk of the disease in all three models (p < 0.05). Additionally, patients with rs80356779 G > A and rs3019594 C > T exhibited lower expression and serum concentration of CPT1A compared with wile types, and patients with rs888663 T > G and rs4808793 G > C exhibited higher serum and expression level of GDF15.

CONCLUSION

The results provided new clues for the role of ferroptosis in LUAD and new potential targets for screening of susceptible population.

Fatty acid metabolism: A new target for nasopharyngeal carcinoma therapy

Lipid metabolic reprogramming is considered one of the most prominent metabolic abnormalities in cancer, and fatty acid metabolism is a key aspect of lipid metabolism. Recent studies have shown that fatty acid metabolism and its related lipid metabolic pathways play important roles in the malignant progression of nasopharyngeal carcinoma (NPC). NPC cells adapt to harsh environments by enhancing biological processes such as fatty acid metabolism, uptake, production, and oxidation, thereby accelerating their growth. In addition, the reprogramming of fatty acid metabolism plays a central role in the tumor microenvironment (TME) of NPC, and the phenotypic transformation of immune cells is closely related to fatty acid metabolism. Moreover, the reprogramming of fatty acid metabolism in NPC contributes to immune escape, which significantly affects disease treatment, progression, recurrence, and metastasis. This review explores recent advances in fatty acid metabolism in NPC and focuses on the interconnections among metabolic reprogramming, tumor immunity, and corresponding therapies. In conclusion, fatty acid metabolism represents a potential target for NPC treatment, and further exploration is needed to develop strategies that target the interaction between fatty acid metabolic reprogramming and immunotherapy.

RNF5 exacerbates steatotic HCC by enhancing fatty acid oxidation via the improvement of CPT1A stability

Non-alcoholic fatty liver disease (NAFLD) is expected to become the leading risk factor for liver cancer, surpassing viral hepatitis. Unlike viral hepatitis-related hepatocellular carcinoma (HCC), the role of excessive nutrient supply in steatotic HCC is not well understood, hindering effective prevention and treatment strategies. Therefore, it is crucial to identify key molecules in the pathogenesis of steatotic HCC, investigate changes in metabolic reprogramming due to excessive fatty acid (FA) supply, understand its molecular mechanisms, and find potential therapeutic targets. Trans-species transcriptome analysis identified Ring Finger Protein 5 (RNF5) as a critical regulator of steatotic HCC. RNF5 upregulation is associated with poor prognosis in steatotic HCC compared to canonical HCC. In vitro and in vivo studies showed that RNF5 exacerbates HCC in the presence of additional FA supply. Lipidomics and transcriptome analyses revealed that RNF5 significantly increases carnitine palmitoyltransferase 1A (CPT1A) mRNA levels and is positively correlated with fatty acid oxidation (FAO). Protein interaction analysis demonstrated that RNF5 promotes K63-type ubiquitination of insulin-like growth factor-2 mRNA-binding protein 1 (IGF2BP1), enhancing CPT1A mRNA stabilization through m6A modification. Additionally, peroxisome proliferator-activated receptor gamma (PPARγ) was found to activate RNF5 expression specifically in HCC cells. Mechanistically, excessive exogenous FAs reorganize FA metabolism in HCC cells, worsening steatotic HCC via the PPARγ-RNF5-IGF2BP1-CPT1A axis. This study highlights a distinct FA metabolism pattern in steatotic HCC, providing valuable insights for potential therapeutic targets.

USP10 deubiquitinates and stabilizes CD44 leading to enhanced breast cancer cell proliferation, stemness and metastasis

Despite extensive research, strategies to effectively combat breast cancer stemness and achieve a definitive cure remains elusive. CD44, a well-defined cancer stem cell (CSC) marker is reported to promote breast cancer tumorigenesis, metastasis, and chemoresistance. However, mechanisms leading to its enhanced expression and function is poorly understood. Here, we demonstrate that USP10 positively regulates CD44 protein levels and its downstream actions. While USP10 depletion prominently down-regulates CD44 protein levels and functions, its overexpression significantly enhances CD44 protein levels, leading to enhanced cluster tumor cell formation, stemness, and metastasis in breast cancer cells both in vitro and ex vivo in primary human breast tumor cells. USP10 interacts with CD44 and stabilizes it through deubiquitination both in breast cancer cell lines and human breast cancer-derived primary tumor cells. Stabilized CD44 shows enhanced interaction with cytoskeleton proteins Ezrin/Radixin/Moesin and potently activates PDGFRβ/STAT3 signaling which are involved in promoting CSC traits. Using USP10 stably expressing 4T1 cells, we further demonstrate that the USP10-CD44 axis potently promotes tumorigenicity in vivo in mice, while simultaneous depletion of CD44 in these cells renders them ineffective. In line with these findings, we further showed that inhibition of USP10 either through RNAi or the pharmacological inhibitor Spautin-1 significantly mitigated CD44 levels and its downstream function ex vivo in primary breast tumor cells. Finally, we demonstrated that primary breast tumor cells are more susceptible to chemotherapy when co-treated with USP10 inhibitor indicating that the USP10-CD44 axis could be an attractive therapeutic target in combination with chemotherapy in CD44 expressing breast cancers.

TRF-16 Inhibits Lung Cancer Progression by Hindering the N6-Methyladenosine Modification of CPT1A mRNA

Transfer RNA-derived fragments (tRFs) are a new class of small non-coding RNAs. Recent studies suggest that tRFs participate in some pathological processes. However, the biological activities and processes of tRFs in lung cancer cells remain mainly unclear. In the present investigation, we employed tRNA-derived small RNA (tsRNA) sequencing to predict differentially expressed tsRNAs in lung cancer cells, and nine tsRNAs with significant expression alterations were validated using qPCR. Wound healing, colony formation, transwell invasion and CCK-8 assays were performed to detect the effects of tRF-16 on cell function. Western blotting evaluated the relationship between tRF-16 and the IGF2BP1 axis. Our findings demonstrated that tRF-16 expression was substantially downregulated in lung cancer cells. TRF-16 could inhibit lung cancer cells' ability to increase, migrate, invade and obtain radiation resistance. Furthermore, tRF-16 decreases the stability of CPT1A by impairing the binding of IGF2BP1 to CPT1A. As a result, the fatty acid metabolism in lung cancer cells was inhibited. Finally, tRF-16 also inhibits lung cancer cell proliferation in vivo. This study shows that tRF-16 plays a crucial regulatory role in the proliferation of lung cancer cells and may represent a novel avenue for their regulation.

USP10 promotes pancreatic ductal adenocarcinoma progression by attenuating FOXC1 protein degradation to activate the WNT signaling pathway

Increasing evidence has suggested that ubiquitin-specific protease 10 (USP10), a deubiquitinating enzyme, plays an essential role in targeted protein degradation and participates in cancer progression. However, the relationship between USP10 and pancreatic ductal adenocarcinoma (PDAC) is poorly understood. Here, we developed a USP-targeting siRNA library, combining a loss-of-function experimental screen in patient-derived PDAC cells. This approach identified USP10 as a master regulator of PDAC cell migration. High USP10 expression levels were observed in PDAC patient tissues, which were associated with poor prognosis. Furthermore, knockdown of USP10 expression inhibited PDAC cell proliferation and migration in vivo and in vitro. Mechanistically, USP10 increased FOXC1 protein stability via deubiquitination. The phosphorylation of FOXC1 at S272A was dependent on USP10-mediated deubiquitination of FOXC1. Additionally, USP10 promoted FOXC1 protein localization in the nucleus. Interestingly, FOXC1 could increase USP10 mRNA expression levels by transcriptional activation. Our data suggest that a positive feedback loop exists between USP10 and FOXC1 that can activate WNT signaling, thus facilitating PDAC malignant progression. Therefore, USP10 represents an exciting therapeutic target that could support new strategies for treating PDAC.

Insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) in hematological diseases

The oncofetal mRNA-binding protein IGF2BP1 belongs to a conserved family of RNA-binding proteins. It primarily promotes RNA stability, regulates translation and RNA localization, and mediates gene expression through its downstream effectors. Numerous studies have demonstrated that IGF2BP1 plays crucial roles in embryogenesis and carcinogenesis. IGF2BP1-modulated cell proliferation, invasion, and chemo-resistance in solid tumors have attracted researchers' attention. Additionally, several studies have highlighted the importance of IGF2BP1 in hematologic malignancies and hematological genetic diseases, positioning it as a promising therapeutic target for hematological disorders. However, there is a lack of systematic summaries regarding the IGF2BP1 gene within the hematological field. In this review, we provide a comprehensive overview of the discovery and molecular structure of IGF2BP1, along with recent studies on its role in regulating embryogenesis. We also focus on the mechanisms by which IGF2BP1 regulates hematological malignancies through its interactions with its targeted mRNAs. Furthermore, we systematically elucidate the function and mechanism of IGF2BP1 in promoting fetal hemoglobin expression in adult hematopoietic stem/progenitor cells. Finally, we discuss the limitations and challenges of IGF2BP1 as a therapeutic target, offering insights into its prospects.

Reading the m6A-encoded epitranscriptomic information in development and diseases

N6-methyladenosine (m6A) represents the most prevalent internal and reversible modification on RNAs. Different cell types display their unique m6A profiles, which are determined by the functions of m6A writers and erasers. M6A modifications lead to different outcomes such as decay, stabilization, or transport of the RNAs. The m6A-encoded epigenetic information is interpreted by m6A readers and their interacting proteins. M6A readers are essential for different biological processes, and the defects in m6A readers have been discovered in diverse diseases. Here, we review the latest advances in the roles of m6A readers in development and diseases. These recent studies not only highlight the importance of m6A readers in regulating cell fate transitions, but also point to the potential application of drugs targeting m6A readers in diseases.

Role of N6-methyladenosine RNA modification in cancer

N6-methyladenosine (m6A) is the most abundant modification of RNA in eukaryotic cells. Previous studies have shown that m6A is pivotal in diverse diseases especially cancer. m6A corelates with the initiation, progression, resistance, invasion, and metastasis of cancer. However, despite these insights, a comprehensive understanding of its specific roles and mechanisms within the complex landscape of cancer is still elusive. This review begins by outlining the key regulatory proteins of m6A modification and their posttranslational modifications (PTMs), as well as the role in chromatin accessibility and transcriptional activity within cancer cells. Additionally, it highlights that m6A modifications impact cancer progression by modulating programmed cell death mechanisms and affecting the tumor microenvironment through various cancer-associated immune cells. Furthermore, the review discusses how microorganisms can induce enduring epigenetic changes and oncogenic effect in microorganism-associated cancers by altering m6A modifications. Last, it delves into the role of m6A modification in cancer immunotherapy, encompassing RNA therapy, immune checkpoint blockade, cytokine therapy, adoptive cell transfer therapy, and direct targeting of m6A regulators. Overall, this review clarifies the multifaceted role of m6A modification in cancer and explores targeted therapies aimed at manipulating m6A modification, aiming to advance cancer research and improve patient outcomes.

ZDHHC1 downregulates LIPG and inhibits colorectal cancer growth via IGF2BP1 Palmitoylation

Alteration in lipid metabolism is recognized as a hallmark feature of colorectal cancer (CRC). Protein S-palmitoylation plays a critical role in many different cellular processes including protein-lipid interaction. Zinc Finger DHHC-Type Containing 1 (ZDHHC1, also known as ZNF377) belongs to the palmitoyl-transferase ZDHHC family, and is a potential tumor suppressor. However, our knowledge of the functional roles of ZDHHC1 in CRC is limited. We discovered that ZDHHC1 expression was downregulated in CRC tissues and that low levels of ZDHHC1 were associated with unfavorable prognosis. Functional studies showed that ZDHHC1 inhibited CRC cell proliferation and invasion in vitro and in vivo. We also found that lipase G (LIPG) is negatively regulated by ZDHHC1 and plays a key role in CRC cell growth through lipid storage. Additionally, we demonstrated that ZDHHC1 functions as a IGF2BP1-palmitoylating enzyme that induces S-palmitoylation at IGF2BP1-C337, which results in downregulated LIPG expression via m6A modification. Mechanistic investigations revealed that the ZDHHC1/IGF2BP1/LIPG signaling axis is associated with inhibition of CRC cell growth. Our study uncovers the potential role of ZDHHC1 in CRC, including inhibition of CRC growth by reducing the stability of LIPG mRNA in an m6A dependent-manner by palmitoylation of IGF2BP1.

Functions and mechanisms of RNA m6A regulators in breast cancer (Review)

Breast cancer (BC) is a major malignant tumor in females and the incidence rate of BC has increased worldwide in recent years. N6‑methyladenosine (m6A) is a methylation modification that occurs extensively in eukaryotic RNA. The abnormal expression of m6A and related regulatory proteins can activate or inhibit certain signal pathways or oncogenes, thus affecting the proliferation, metastasis and prognosis of BC. Numerous studies have shown that m6A regulator disorder exists in BC, and this disorder can be reversed. Therefore, m6A is predicted as a potential therapeutic target for BC. However, the molecular mechanism of m6A RNA methylation regulating the occurrence and development of BC has not been comprehensively elucidated. In this review article, the functions of various m6A regulators and the specific mechanisms of certain regulators of the progress of BC were summarized. Furthermore, the dual role of RNA methylation in tumor progression was discussed, concluding that RNA methylation can not only lead to tumorigenesis but at times give rise to inhibition of tumor formation. In addition, further comprehensive analysis on mechanisms of m6A regulators in BC is conducive to screening effective potential targets and formulating targeted treatment strategies, which will provide new methods for the prevention and treatment of BC.

Deoxynivalenol induces m6A-mediated upregulation of p21 and growth arrest of mouse hippocampal neuron cells in vitro

Hippocampal neurons maintain the ability of proliferation throughout life to support neurogenesis. Deoxynivalenol (DON) is a mycotoxin that exhibits brain toxicity, yet whether and how DON affects hippocampal neurogenesis remains unknown. Here, we use mouse hippocampal neuron cells (HT-22) as a model to illustrate the effects of DON on neuron proliferation and to explore underlying mechanisms. DON exposure significantly inhibits the proliferation of HT-22 cells, which is associated with an up-regulation of cell cycle inhibitor p21 at both mRNA and protein levels. Global and site-specific m6A methylation levels on the 3'UTR of p21 mRNA are significantly increased in response to DON treatment, whereas inhibition of m6A hypermethylation significantly alleviates DON-induced cell cycle arrest. Further mechanistic studies indicate that the m6A readers YTHDF1 and IGF2BP1 are responsible for m6A-mediated increase in p21 mRNA stability. Meanwhile, 3'UTR of E3 ubiquitin ligase TRIM21 mRNA is also m6A hypermethylated, and another m6A reader YTHDF2 binds to the m6A sites, leading to decreased TRIM21 mRNA stability. Consequently, TRIM21 suppression impairs ubiquitin-mediated p21 protein degradation. Taken together, m6A-mediated upregulation of p21, at both post-transcriptional and post-translational levels, contributes to DON-induced inhibition of hippocampal neuron proliferation. These results may provide new insights for epigenetic therapy of neurodegenerative diseases.

METTL3 orchestrates glycolysis by stabilizing the c-Myc/WDR5 complex in triple-negative breast cancer

BACKGROUND

The carcinogenic transcription factor c-Myc is the most aggressive oncogene, which drive malignant transformation and dissemination of triple-negative breast cancer (TNBC). Recruitment of many cofactors, especially WDR5, a protein that nucleates H3K4me chromatin modifying complexes, play a pivotal role in regulating c-Myc-dependent gene transcription, a critical process for c-Myc signaling to function in a variety of biological and pathological contexts. For this reason, interrupting the interaction between c-Myc and the transcription cofactor WDR5 may become the most promising new strategy for treating c-Myc driven TNBC.

METHODS

Immunoprecipitation and mass spectrometry (IP-MS) is used to screen proteins that bind c-Myc/WDR5 interactions. The interaction of METTL3 with c-Myc/WDR5 in breast cancer tissues and TNBC cells was detected by Co-IP and immunofluorescence. Subsequently, we further analyzed the influence of METTL3 expression on c-Myc/WDR5 protein expression and its interaction stability by Western blot and Co-IP. The correlation between METTL3 and c-Myc pathway was analyzed by ChIP-seq sequencing and METTL3 knockdown transcriptome data. The effect of METTL3 expression on c-Myc transcriptional activity was detected by ChIP-qPCR and Dual Luciferase Reporter. At the same time, the overexpression vector METTL3-MUT (m6A) was constructed, which mutated the methyltransferase active site (Aa395-398, DPPW/APPA), and further explored whether the interaction between METTL3 and c-Myc/WDR5 was independent of methyltransferase activity. In addition, we also detected the changes of METTL3 expression on TNBC's sensitivity to small molecule inhibitors such as JQ1 and OICR9429 by CCK8, Transwell and clonal formation assays. Finally, we further verified our conclusions in spontaneous tumor formation mouse MMTV-PyMT and nude mouse orthotopic transplantation tumor models.

RESULTS

METTL3 was found to bind mainly to c-Myc/WDR5 protein in the nucleus. It enhances the stability of c-Myc/WDR5 interaction through its methyltransferase independent mechanism, thereby enhancing the transcriptional activity of c-Myc on downstream glucose metabolism genes. Notably, the study also confirmed that METTL3 can directly participate in the transcription of glucose metabolism genes as a transcription factor, and knockdown METTL3 enhances the drug sensitivity of breast cancer cells to small molecule inhibitors JQ1 and OICR9429. The study was further confirmed by spontaneous tumor formation mouse MMTV-PyMT and nude mouse orthotopic transplantation tumor models.

CONCLUSION

METTL3 binds to the c-Myc/WDR5 protein complex and promotes glycolysis, which plays a powerful role in promoting TNBC progression. Our findings further broaden our understanding of the role and mechanism of action of METTL3, and may open up new therapeutic avenues for effective treatment of TNBC with high c-Myc expression.

circRNA6448-14/miR-455-3p/OTUB2 axis stimulates glycolysis and stemness of esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is a gastrointestinal malignancy with high incidence. This study aimed to reveal the complete circRNA-miRNA-mRNA regulatory network in ESCC and validate its function mechanism.

METHOD

Expression of OTU Domain-Containing Ubiquitin Aldehyde-Binding Protein 2 (OTUB2) in ESCC was analyzed by bioinformatics to find the binding sites between circRNA6448-14 and miR-455-3p, as well as miR-455-3p and OTUB2. The binding relationships were verified by RNA Immunoprecipitation (RIP) and dual-luciferase assay. The expressions of circRNA6448-14, miR-455-3p, and OTUB2 were detected by quantitative real-time polymerase chain reaction (qRT-PCR). MTT assay measured cell viability, and the spheroid formation assay assessed the ability of stem cell sphere formation. Western blot (WB) determined the expression of marker proteins of stem cell surface and rate-limiting enzyme of glycolysis. The Seahorse XFe96 extracellular flux analyzer measured the rate of extracellular acidification rate and cellular oxygen consumption. Corresponding assay kits assessed cellular glucose consumption, lactate production, and adenosine triphosphate (ATP) generation.

RESULTS

In ESCC, circRNA6448-14 and OTUB2 were highly expressed in contrast to miR-455-3p. Knocking down circRNA6448-14 could prevent the glycolysis and stemness of ESCC cells. Additionally, circRNA6448-14 enhanced the expression of OTUB2 by sponging miR-455-3p. Overexpression of OTUB2 or silencing miR-455-3p reversed the inhibitory effect of knockdown of circRNA6448-14 on ESCC glycolysis and stemness.

CONCLUSION

This research demonstrated that the circRNA6448-14/miR-455-3p/OTUB2 axis induced the glycolysis and stemness of ESCC cells. Our study revealed a novel function of circRNA6448-14, which may serve as a potential therapeutic target for ESCC.

K48-linked deubiquitination of VGLL4 by USP15 enhances the efficacy of tumor immunotherapy in triple-negative breast cancer

Immunotherapy based on PD-1/PD-L1 antagonists has been demonstrated to be efficacious in inducing tumor remission in patients with triple-negative breast cancer (TNBC). However, tumor immune evasion caused by the PD-1/PD-L1 pathway inhibits the immunotherapeutic effect of PD-1/PD-L1 inhibitors against TNBC. Therefore, identifying potential targets for blocking the PD-1/PD-L1 pathway is a compelling strategy for TNBC treatment. Here, we discovered that VGLL4 could inhibit PD-L1 transcription by suppressing STAT3 activation, thereby enhancing the efficacy of anti-PD-1 antibody immunotherapy in TNBC. Low expression of USP15, a deubiquitinating enzyme of VGLL4, was associated with reduced CD8+ T cell infiltration and poor prognosis in TNBC patients. USP15 was found to inhibit PD-L1 transcription, leading to increased CD8+ T cell infiltration and thus enhancing the efficacy of TNBC immunotherapy. Furthermore, SART3 regulated VGLL4 stability and PD-L1 transcription by influencing the nuclear translocation of USP15. In conclusion, our study provides new insights into the biological regulation of PD-L1, identifies a previously unrecognized regulator of this critical immune checkpoint, and highlights potential therapeutic targets for overcoming immune evasion in TNBC.

Targeting Dysregulated Lipid Metabolism in Cancer with Pharmacological Inhibitors

Metabolic plasticity is recognised as a hallmark of cancer cells, enabling adaptation to microenvironmental changes throughout tumour progression. A dysregulated lipid metabolism plays a pivotal role in promoting oncogenesis. Oncogenic signalling pathways, such as PI3K/AKT/mTOR, JAK/STAT, Hippo, and NF-kB, intersect with the lipid metabolism to drive tumour progression. Furthermore, altered lipid signalling in the tumour microenvironment contributes to immune dysfunction, exacerbating oncogenesis. This review examines the role of lipid metabolism in tumour initiation, invasion, metastasis, and cancer stem cell maintenance. We highlight cybernetic networks in lipid metabolism to uncover avenues for cancer diagnostics, prognostics, and therapeutics.

Targeting insulin-like growth factor 2 mRNA-binding proteins (IGF2BPs) for the treatment of cancer

Insulin-like growth factor 2 mRNA-binding proteins (IMPs, IGF2BPs) are RNA-binding proteins that regulate a variety of biological processes. In recent years, several studies have found that IGF2BPs play multiple roles in various biological processes, especially in cancer, and speculated on their mechanism of anticancer effect. In addition, targeting IGF2BPs or their downstream target gene has also received extensive attention as an effective treatment for different types of cancer. In this review, we summarized the recent progress on the role of IGF2BPs in cancers and their structural characteristics. We focused on describing the development of inhibitors targeting IGF2BPs and the prospects for further applications.

Ubiquitination and deubiquitination in the regulation of N6-methyladenosine functional molecules

N6 methyladenosine (m6A) is the most prevalent RNA epigenetic modification, regulated by methyltransferases and demethyltransferases and recognized by methylation-related reading proteins to impact mRNA splicing, translocation, stability, and translation efficiency. It significantly affects a variety of activities, including stem cell maintenance and differentiation, tumor formation, immune regulation, and metabolic disorders. Ubiquitination refers to the specific modification of target proteins by ubiquitin molecule in response to a series of enzymes. E3 ligases connect ubiquitin to target proteins and usually lead to protein degradation. On the contrary, deubiquitination induced by deubiquitinating enzymes (DUBs) can separate ubiquitin and regulate the stability of protein. Recent studies have emphasized the potential importance of ubiquitination and deubiquitination in controlling the function of m6A modification. In this review, we discuss the impact of ubiquitination and deubiquitination on m6A functional molecules in diseases, such as metabolism, cellular stress, and tumor growth.

METTL3 Promotes Osteogenic Differentiation of Human Periodontal Ligament Stem Cells through IGF2BP1-Mediated Regulation of Runx2 Stability

N6-Methyladenosine (m6A) has been reported to play a dynamic role in osteoporosis and bone metabolism. However, whether m6A is involved in the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) remains unclear. Here, we found that methyltransferase-like 3 (METTL3) was up-regulated synchronously with m6A during the osteogenic differentiation of hPDLSCs. Functionally, lentivirus-mediated knockdown of METTL3 in hPDLSCs impaired osteogenic potential. Mechanistic analysis further showed that METTL3 knockdown decreased m6A methylation and reduced IGF2BP1-mediated stability of runt-related transcription factor 2 (Runx2) mRNA, which in turn inhibited osteogenic differentiation. Therefore, METTL3-based m6A modification favored osteogenic differentiation of hPDLSCs through IGF2BP1-mediated Runx2 mRNA stability. Our study shed light on the critical roles of m6A on regulation of osteogenic differentiation in hPDLSCs and served novel therapeutic approaches in vital periodontitis therapy.

CRD-BP as a Tumor Marker of Colorectal Cancer

The National Cancer Center published a comparative report on cancer data between China and the United States in the Chinese Medical Journal, which shows that colorectal cancer (CRC) ranks second in China and fourth in the United States. It is worth noting that since 2000, the case fatality rate of CRC in China has skyrocketed, while the United States has gradually declined. Finding tumor markers with high sensitivity and specificity is our primary goal to reduce the case fatality rate of CRC. Studies have shown that CRD-BP (Insulin-like growth factor 2 mRNA-binding protein 1) can affect a variety of signaling pathways, such as Wnt.nuclear factor KB (NF-κB), and Hedgehog, and has good biological effects as a therapeutic target for CRC. CRD-BP is expected to become a tumor marker with high sensitivity and specificity of CRC. This paper reviews the research on CRD-BP as a tumor marker of CRC.

IGF2BP1 enhances the stability of SIK2 mRNA through m6A modification to promote non-small cell lung cancer progression

BACKGROUND

Non-small cell lung cancer (NSCLC) is a significant public health concern globally. Evidence suggests that Salt-inducible kinase 2 (SIK2) is differentially expressed across various cancers and is also implicated in cancer progression. Despite this, the precise function of SIK2 in NSCLC is yet to be elucidated and requires further investigation.

METHODS

SIK2 expression was evaluated in both HBEC and NSCLC cells, utilizing quantitative real-time PCR (qRT-PCR) and Western blot (WB) analyses. Furthermore, to identify the influence of SIK2 on cell proliferation, migration, invasion, and apoptosis, a range of techniques were employed. To evaluate N6-methyladenosine (m6A) modification levels of total RNA and SIK2 within cells, RNA m6A colorimetry and methylated RNA immunoprecipitation (MeRIP) techniques were employed. Additionally, to confirm the interaction between SIK2 and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1), bioinformatics analysis was executed, and the results were validated through RIP. The stability of SIK2 mRNA was determined using actinomycin D experiment. Furthermore, to validate the in vivo functionality of SIK2, a subcutaneous transplantation tumor model was established in nude mice.

RESULTS

In this study, upregulation of SIK2 in NSCLC cells was observed. Overexpression of SIK2 was found to lead to promotion of cell proliferation, migration, invasion, and suppression of the Hippo/yes-associated protein (YAP) pathway, while inhibiting apoptosis. RIP analysis showed that IGF2BP1 protein interacted with SIK2 mRNA. Knockdown of IGF2BP1 decreased mRNA stability and m6A modification levels of SIK2. Additionally, knockdown of IGF2BP1 resulted in inhibition of cell proliferation, migration, invasion, suppression of the Hippo/YAP pathway, and promoting apoptosis. Overexpression of SIK2 overturned the impact of IGF2BP1 on NSCLC cells, which was then confirmed through in vivo experiments.

CONCLUSION

IGF2BP1 stabilized SIK2 mRNA through m6A modification to promote NSCLC progression, potentially offering new diagnostic and therapeutic insights for NSCLC.

N6-methyladenosine of TRIM27 enhances the stem cell-type phenotype of cisplatin-resistant colorectal cancer cells

Colorectal cancer (CRC), classified as a lethal form of cancer, substantially threatens human well-being. Cancer stem cells (CSCs) reflect subsets for cancerous cells having basic stem-cell type properties, being significantly involved in the development of chemoresistance and tumor relapsing. The aberrant TRIM27 expression in various types of cancer indicates its potential involvement in cancer growth and progression. The current understanding of the TRIM27 involvement in CRC remains limited. In current study indicated that TRIM27 can potentially promote CSC-type phenotype of Cisplatin (DDP)-resistant CRC cells. YTHDF1 recruitment onto m6A-amended TRIM27 was crucial for facilitating the TRIM27 translating process in DDP-resistant CRC cells. The present research proposes that TRIM27 exhibits an oncogenic role by enhancing the CSC-type properties in DDP-resistant CRC via the m6A-modified pathway. The potential therapy for combating the relapse of CRC may include TRIM27 and YTHDF1, as they have been found to have significant roles in promoting CSC-type phenotypic characteristics.

USP10 promotes the progression of triple-negative breast cancer by enhancing the stability of TCF4 protein

Investigating the role of ubiquitin-specific peptidase 10 (USP10) in triple-negative breast cancer (TNBC). Analyzed USP10 expression levels in tumors using public databases. Detected USP10 mRNA and protein levels in cell lines. Examined USP10 expression in tumor tissues from breast cancer patients. Conducted USP10 knockdown experiments and analyzed changes in cell proliferation and metastasis. Confirmed protein-protein interactions with USP10 through mass spectrometry, Co-IP, and fluorescence experiments. Assessed impact of USP10 on transcription factor 4 (TCF4) ubiquitination and validated TCF4's influence on TNBC cells. We initially identified a pronounced overexpression of USP10 across multiple tumor types, including TNBC. Subsequently, we observed a conspicuous upregulation of USP10 expression levels in breast cancer cell lines compared to normal breast epithelial cells. However, upon subsequent depletion of USP10 within cellular contexts, we noted a substantial attenuation of malignant proliferation and metastatic potential in TNBC cells. In subsequent experimental analyses, we elucidated the physical interaction between USP10 and the transcription factor TCF4, whereby USP10 facilitated the deubiquitination modification of TCF4, consequently promoting its protein stability and contributing to the initiation and progression of TNBC. Collectively, this study demonstrates that USP10 facilitated the deubiquitination modification of TCF4, consequently promoting its protein stability and contributing to the initiation and progression of TNBC.

USP10 promotes intrahepatic cholangiocarcinoma cell survival and stemness via SNAI1 deubiquitination

Cancer cell stemness contributes significantly to intrahepatic cholangiocarcinoma (ICC) progression. However, the roles of deubiquitinating enzymes (DUBs) in ICC modulation are poorly understood. Ubiquitin specific peptidase 10 (USP10) was highly expressed in ICC spheres. The interaction between USP10 and snail family transcriptional repressor 1 (SNAI1) reduced the polyubiquitination of the SNAI1 protein and stabilized the SNAI1 protein. USP10 knockdown in RBE cells inhibited cell proliferation, promoted cell apoptosis and decreased the diameter of the formed spheres and the expression levels of CD44, EpCAM, OCT4 and SOX2. SNAI1 overexpression alleviated the effect of USP10 knockdown in RBE cells. In addition, the knockdown of USP10 attenuated the ability of RBE cells to form tumors subcutaneously in nude mice. Our results revealed that USP10 attenuates ICC cell malignancy by deubiquitinating SNAI1, indicating that USP10 could be developed as a therapeutic target for ICC treatment.

Regulatory mechanisms and therapeutic implications of insulin-like growth factor 2 mRNA-binding proteins, the emerging crucial m6A regulators of tumors

Insulin-like growth factor 2 mRNA-binding proteins (IGF2BPs) serve essential biological functions as post-transcriptional performers, participating in the acquisition or maintenance of tumor hallmarks due to their distinct protein structures. Emerging evidence indicates that IGF2BPs belong to the class III type of RNA N6-methyladenosine (m6A) modification readers, controlling RNA stability, storage, localization, metabolism, and translation in multiple vital bioprocesses, particularly tumorigenesis and tumor progression. Here, we discuss the underlying regulatory mechanisms and pathological functions of IGF2BPs which act as m6A readers in the context of tumor pathogenesis and multidrug resistance. Furthermore, we highlight the potential of IGF2BPs as drug targets in clinical tumor treatment. Hence, precise and novel tumor therapeutic approaches could be uncovered by targeting epigenetic heterogeneity.

The ubiquitin-proteasome system in breast cancer

Ubiquitin-proteasome system (UPS) is a selective proteolytic system that is associated with the expression or function of target proteins and participates in various physiological and pathological processes of breast cancer. Inhibitors targeting the 26S proteasome in combination with other drugs have shown promising therapeutic effects in the clinical treatment of breast cancer. Moreover, several inhibitors/stimulators targeting other UPS components are also effective in preclinical studies, but have not yet been applied in the clinical treatment of breast cancer. Therefore, it is vital to comprehensively understand the functions of ubiquitination in breast cancer and to identify potential tumor promoters or tumor suppressors among UPS family members, with the aim of developing more effective and specific inhibitors/stimulators targeting specific components of this system.

Targeted therapy based on ubiquitin-specific proteases, signalling pathways and E3 ligases in non-small-cell lung cancer

Lung cancer is one of the most common malignant tumours worldwide, with the highest mortality rate. Approximately 1.6 million deaths owing to lung cancer are reported annually; of which, 85% of deaths occur owing to non-small-cell lung cancer (NSCLC). At present, the conventional treatment methods for NSCLC include radiotherapy, chemotherapy, targeted therapy and surgery. However, drug resistance and tumour invasion or metastasis often lead to treatment failure. The ubiquitin–proteasome pathway (UPP) plays an important role in the occurrence and development of tumours. Upregulation or inhibition of proteins or enzymes involved in UPP can promote or inhibit the occurrence and development of tumours, respectively. As regulators of UPP, ubiquitin-specific proteases (USPs) primarily inhibit the degradation of target proteins by proteasomes through deubiquitination and hence play a carcinogenic or anticancer role. This review focuses on the role of USPs in the occurrence and development of NSCLC and the potential of corresponding targeted drugs, PROTACs and small-molecule inhibitors in the treatment of NSCLC.