Circular RNA circ-TNPO3 inhibits clear cell renal cell carcinoma metastasis by binding to IGF2BP2 and destabilizing SERPINH1 mRNA

The crosstalk between alternative splicing and circular RNA in cancer: pathogenic insights and therapeutic implications

RNA splicing is a fundamental step of gene expression. While constitutive splicing removes introns and joins exons unbiasedly, alternative splicing (AS) selectively determines the assembly of exons and introns to generate RNA variants corresponding to the same transcript. The biogenesis of circular RNAs (circRNAs) is inextricably associated with AS. Back-splicing, the biogenic process of circRNA, is a special form of AS. In cancer, both AS and circRNA deviate from the original track. In the present review, we delve into the intricate interplay between AS and circRNAs in the context of cancer. The relationship between AS and circRNAs is intricate, where AS modulates the biogenesis of circRNAs and circRNAs in return regulate AS events. Beyond that, epigenetic and posttranscriptional modifications concurrently regulate AS and circRNAs. On the basis of this modality, we summarize current knowledge on how splicing factors and other RNA binding proteins regulate circRNA biogenesis, and how circRNAs interact with splicing factors to influence AS events. Specifically, the feedback loop regulation between circRNAs and AS events contributes greatly to oncogenesis and cancer progression. In summary, resolving the crosstalk between AS and circRNA will not only provide better insight into cancer biology but also provoke novel strategies to combat cancer.

The role of circular RNA targeting IGF2BPs in cancer-a potential target for cancer therapy

Circular RNAs (circRNAs) are an interesting class of conserved single-stranded RNA molecules derived from exon or intron sequences produced by the reverse splicing of precursor mRNA. CircRNAs play important roles as microRNA sponges, gene splicing and transcriptional regulators, RNA-binding protein sponges, and protein/peptide translation factors. Abnormal functions of circRNAs and RBPs in tumor progression have been widely reported. Insulin-like growth factor-2 mRNA-binding proteins (IGF2BPs) are a highly conserved family of RBPs identified in humans that function as post-transcriptional fine-tuners of target transcripts. Emerging evidence suggests that IGF2BPs regulate the processing and metabolism of RNA, including its stability, translation, and localization, and participate in a variety of cellular functions and pathophysiology. In this review, we have summarized the roles and molecular mechanisms of circRNAs and IGF2BPs in cancer development and progression. In addition, we briefly introduce the role of other RNAs and IGF2BPs in cancer, discuss the current clinical applications and challenges faced by circRNAs and IGF2BPs, and propose future directions for this promising research field.

Establishment of RNA modification regulators index predicting clinical outcomes and immune relevance of kidney cancer patients

Increasing evidence indicates that RNA modifications are misregulated in human cancers, which might be optimal targets of cancer therapy. However, important RNA regulators in kidney cancer still need further exploration. In this study, we collected regulators representing different types of RNA modification and identified the prognosis-related RNA regulators in kidney cancer patients. We further constructed a 4-gene RNA regulators signature and index called prognosis-related RNA regulators index (PRRI) by the Lasso-Cox regression algorithm. We found that PRRI could precisely predict prognosis of patients in the KIRC training (AUC at 3-/5-/7-years = 0.7132/0.7220/0.7283) and testing cohorts (AUC at 3-/5-/7-years = 0.7141/0.7403/0.7305) and two independent RCC cohorts - E-MTAB-1980 (AUC at 3-/5-/7-years = 0.7036/0.7385/0.7143) and KIRP (AUC at 3-/5-/7-years = 0.6203/0.6365/0.6941). Moreover, the high PRRI group showed a worse clinical outcome than the low PRRI group. PRRI demonstrated strong robustness and was related to histological grade and pathologic stage, which was also found to be an independent prognosis factor when other clinical variables adjusted it. We further found several immune-related pathways differentially enriched in the high or low PRRI group. The regulation of T cell migration, which has been proven to be an immunosuppressive cell, shows a high enrichment in the high PRRI group. Further analysis reveals that PRRI also shows a highly positive correlation with the activity of Tregs. TIDE analysis and two independent immune therapy cohorts revealed that the high PRRI group might resist immune therapy, while the low PRRI group might benefit from the treatment, indicating that PRRI could be a marker for predicting immune therapeutic response. All in all, we determined 4 potentially essential RNA regulators and illustrated their mechanisms concretely. Furthermore, we constructed a 4-gene index called PRRI to predict patients' outcomes and immunotherapy response.

N6-methyladenosine enhances the expression of TGF-β-SMAD signaling family to inhibit cell growth and promote cell metastasis

TGF-β-SMAD signaling pathway plays an important role in the progression of various cancers. However, posttranscriptional regulation such as N6-methyladenosine (m6A) of TGF-β-SMAD signaling axis remains incompletely understood. Here, we reveal that insulin like growth factor 2 mRNA binding protein 2 (IGF2BP2) is low expression as well as associated with poor prognosis in clear cell renal cell carcinoma (ccRCC) patients and inhibits proliferation as well as promotes metastasis of ccRCC cells. Mechanistically, IGF2BP2 systematically regulates TGF-β-SMAD signaling family, including TGF-β1/2, TGF-βR1/2 and SMAD2/3/4, through mediating their mRNA stability in an m6A-dependent manner. Furthermore, the functional effects of IGF2BP2 on ccRCC cells is mediated by TGF-β-SMAD signaling downstream effector SMAD4, which is identified three m6A sites in 5'UTR and CDS. Our study establishes IGF2BP2-TGF-β-SMAD axis as a new regulatory effector in ccRCC, providing new insights for developing novel therapeutic strategies.

Epithelial splicing regulatory protein 1 promotes peritoneal dissemination of ovarian cancer by inducing the formation of circular RNAs modulating epithelial plasticity

Peritoneal metastases prevalently occur in ovarian cancer, deteriorating patient prognosis. During the metastatic cascade, tumor plasticity enables cells to adapt to environmental changes, thereby facilitating dissemination. We previously found that epithelial splicing regulatory protein 1 (ESRP1) is linked to peritoneal metastasis and epithelial-mesenchymal plasticity in ovarian cancer. This study delves into the underlying mechanism. We found that ESRP1 preserves epithelial plasticity in ovarian cancer cells in vitro and in vivo. Functionally, ESRP1 enhances ovarian cancer cell growth and peritoneal dissemination. High-throughput sequencing revealed several ESRP1-related epithelial RNAs, encompassing both linear and circular forms. Specifically, ESRP1 triggers the cyclization of circPAFAH1B2 and circUBAP2 through binding to the GGU sequences in adjacent introns. The two ESRP1-induced circular RNAs stabilize DKK3 and AHR mRNAs, which are critical for epithelial plasticity, through interaction with IGF2BP2. Collectively, ESRP1 triggers the formation of circPAFAH1B2 and circUBAP2, which in turn stabilizes DKK3 and AHR through IGF2BP2 binding, thereby modulating the epithelial plasticity and aiding the peritoneal spread of ovarian cancer cells. The findings unveiled a biological network, orchestrated by ESRP1, that governs the epithelial-mesenchymal plasticity of ovarian cancer cells, emphasizing the therapeutic potential of ESRP1 and its induced circular RNAs for ovarian cancer treatment.

Sulindac (K-80003) with nab-paclitaxel and gemcitabine overcomes drug-resistant pancreatic cancer

The Nab-paclitaxel combined with gemcitabine (AG) regimen is the main chemotherapy regimen for pancreatic cancer, but drug resistance often occurs. Currently, the ability to promote sensitization in drug-resistant cases is an important clinical issue, and the strategy of repurposing conventional drugs is a promising strategy. This study aimed to identify a classic drug that targets chemotherapy resistance's core signaling pathways and combine it with the AG regimen to enhance chemosensitivity. We also aimed to find reliable predictive biomarkers of drug combination sensitivity. Using RNA sequencing, we found that abnormal PI3K/Akt pathway activation plays a central role in mediating resistance to the AG regimen. Subsequently, through internal and external verification of randomly selected AG-resistant patient-derived organoid (PDO) and PDO xenograft models, we discovered for the first time that the classic anti-inflammatory drug sulindac K-80003, an inhibitor of the PI3K/Akt pathway that we focused on, promoted sensitization in half (14/28) of AG-resistant pancreatic ductal adenocarcinoma cases. Through RNA-sequencing, multiplex immunofluorescent staining, and immunohistochemistry experiments, we identified cFAM124A as a novel biomarker through which sulindac K-80003 promotes AG sensitization. Its role as a sensitization marker is explained via the following mechanism: cFAM124A enhances both the mRNA expression of cathepsin L and the activity of the cathepsin L enzyme. This dual effect stimulates the cleavage of RXRα, leading to large amounts of truncated RXRα, which serves as a direct target of K-80003. Consequently, this process results in the pathological activation of the PI3K/Akt pathway. In summary, our study provides a new treatment strategy and novel biological target for patients with drug-resistant pancreatic cancer.

CircSP3 encodes SP3-461aa to promote ccRCC progression via stabilizing MYH9 and activating the PI3K-Akt signaling pathway

Clear cell renal cell carcinoma (ccRCC) is a primary kidney cancer with high aggressive phenotype and extremely poor prognosis. Accumulating evidence suggests that circular RNAs (circRNAs) play pivotal roles in the occurrence and development of various human cancers. However, the expression, clinical significance and regulatory role of circRNAs in ccRCC remain largely unclear. Here we report that circSP3 to be increased in tissues from ccRCC patients and ccRCC cells, and to positively correlate with ccRCC malignant features. Knockdown of circSP3 inhibits proliferation, triggers apoptosis, and reduces migration and invasion in different ccRCC cells in vitro. Correspondingly, circSP3 overexpression Promote ccRCC tumorigenicity in a mouse xenograft model. Mechanistically, circSP3 could bind with the ribosome to initiate the translation process to encodes a novel 461-amino acid peptide referred to as SP3-461aa, which protects the MYH9 protein from proteasomal degradation. SP3-461aa played a pivotal role in mediating the oncogenic effects of circSP3 by interacting with the MYH9 protein and activating the PI3K-Akt signaling pathway. These findings suggested that circSP3 plays an important role in ccRCC development and could be a potential biomarker for the treatment and prognosis of ccRCC.

Therapeutic importance and diagnostic function of circRNAs in urological cancers: from metastasis to drug resistance

Circular RNAs (circRNAs) are a member of non-coding RNAs with no ability in encoding proteins and their aberrant dysregulation is observed in cancers. Their closed-loop structure has increased their stability, and they are reliable biomarkers for cancer diagnosis. Urological cancers have been responsible for high mortality and morbidity worldwide, and developing new strategies in their treatment, especially based on gene therapy, is of importance since these malignant diseases do not respond to conventional therapies. In the current review, three important aims are followed. At the first step, the role of circRNAs in increasing or decreasing the progression of urological cancers is discussed, and the double-edged sword function of them is also highlighted. At the second step, the interaction of circRNAs with molecular targets responsible for urological cancer progression is discussed, and their impact on molecular processes such as apoptosis, autophagy, EMT, and MMPs is highlighted. Finally, the use of circRNAs as biomarkers in the diagnosis and prognosis of urological cancer patients is discussed to translate current findings in the clinic for better treatment of patients. Furthermore, since circRNAs can be transferred to tumor via exosomes and the interactions in tumor microenvironment provided by exosomes such as between macrophages and cancer cells is of importance in cancer progression, a separate section has been devoted to the role of exosomal circRNAs in urological tumors.

Therapeutic SHPRH-146aa encoded by circ-SHPRH dynamically upregulates P21 to inhibit CDKs in neuroblastoma

Recent research has underscored the significance of circular RNAs (circRNAs) in various cancers, including neuroblastoma (NB). Specifically, circ-SHPRH, a unique circRNA, has been revealed to inhibit tumor growth by sequestering miRNAs or producing the SHPRH-146aa protein. To explore circ-SHPRH's involvement in NB and its potential application in gene therapy, this study examined circ-SHPRH expression in 94 NB tissues and cell lines (SK-N-BE(2), SH-SY5Y) using real-time PCR and fluorescence in situ hybridization (FISH). Functional assays encompassing both overexpression and knockdown experiments in NB cell lines, as well as in vivo investigations, were conducted. RNA-seq analysis revealed a correlation between circ-SHPRH and the pathway of P21 (CDKN1A), a pivotal cell cycle regulator. Validation through PCR and other techniques confirmed that circ-SHPRH upregulated P21 expression. Furthermore, the regulatory role of circ-SHPRH in the P21-CDK pathway was corroborated through SHPRH-146aa expression analysis. Notably, adenovirus-mediated circ-SHPRH overexpression effectively curbed NB tumor growth in NSG mice, while combining circ-SHPRH with everolimus exhibited potential for NB treatment. This study elucidates the remarkable significance of circ-SHPRH in NB and its prospective utility in gene therapy, thereby paving the way for innovative therapeutic approaches.

PTBP1 knockdown impairs autophagy flux and inhibits gastric cancer progression through TXNIP-mediated oxidative stress

BACKGROUND

Gastric cancer (GC) is a prevalent malignant tumor, and the RNA-binding protein polypyrimidine tract-binding protein 1 (PTBP1) has been identified as a crucial factor in various tumor types. Moreover, abnormal autophagy levels have been shown to significantly impact tumorigenesis and progression. Despite this, the precise regulatory mechanism of PTBP1 in autophagy regulation in GC remains poorly understood.

METHODS

To assess the expression of PTBP1 in GC, we employed a comprehensive approach utilizing western blot, real-time quantitative polymerase chain reaction (RT-qPCR), and bioinformatics analysis. To further identify the downstream target genes that bind to PTBP1 in GC cells, we utilized RNA immunoprecipitation coupled with sequencing (si-PTBP1 RNA-seq). To evaluate the impact of PTBP1 on gastric carcinogenesis, we conducted CCK-8 assays, colony formation assays, and GC xenograft mouse model assays. Additionally, we utilized a transmission electron microscope, immunofluorescence, flow cytometry, western blot, RT-qPCR, and GC xenograft mouse model experiments to elucidate the specific mechanism underlying PTBP1's regulation of autophagy in GC.

RESULTS

Our findings indicated that PTBP1 was significantly overexpressed in GC tissues compared with adjacent normal tissues. Silencing PTBP1 resulted in abnormal accumulation of autophagosomes, thereby inhibiting GC cell viability both in vitro and in vivo. Mechanistically, interference with PTBP1 promoted the stability of thioredoxin-interacting protein (TXNIP) mRNA, leading to increased TXNIP-mediated oxidative stress. Consequently, this impaired lysosomal function, ultimately resulting in blockage of autophagic flux. Furthermore, our results suggested that interference with PTBP1 enhanced the antitumor effects of chloroquine, both in vitro and in vivo.

CONCLUSION

PTBP1 knockdown impairs GC progression by directly binding to TXNIP mRNA and promoting its expression. Based on these results, PTBP1 emerges as a promising therapeutic target for GC.

IGF2BP2 inhibits invasion and migration of clear cell renal cell carcinoma via targeting Netrin-4 in an m6A-dependent manner

Clear cell renal cell carcinoma (ccRCC), the most common subtype of renal cell carcinoma, often leads to a poor prognosis due to metastasis. The investigation of N6-methyladenosine (m6A) methylation, a crucial RNA modification, and its role in ccRCC, particularly through the m6A reader insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2), revealed significant insights. We found that IGF2BP2 was notably downregulated in ccRCC, which correlated with tumor aggressiveness and poor prognosis. Thus, IGFBP2 has emerged as an independent prognostic factor of ccRCC. Moreover, a strong positive correlation was observed between the expression of IGF2BP2 and Netrin-4. Netrin-4 was also downregulated in ccRCC, and its lower levels were associated with increased malignancy and poor prognosis. Overexpression of IGF2BP2 and Netrin-4 suppressed the invasion and migration of ccRCC cells, while Netrin-4 knockdown reversed these effects in ccRCC cell lines. RNA immunoprecipitation (RIP)-quantitative polymerase chain reaction validated the robust enrichment of Netrin-4 mRNA in anti-IGF2BP2 antibody immunoprecipitates. MeRlP showed significantly increased Netrin4 m6A levels after lGF2BP2 overexpression. Moreover, we found that IGF2BP2 recognized and bound to the m6A site within the coding sequence of Netrin-4, enhancing its mRNA stability. Collectively, these results showed that IGF2BP2 plays a suppressive role in the invasion and migration of ccRCC cells by targeting Netrin-4 in an m6A-dependent manner. These findings underscore the potential of IGF2BP2/Netrin-4 as a promising prognostic biomarker and therapeutic target in patients with ccRCC metastasis.

Targeting HSP47 for cancer treatment

Heat shock protein 47 (HSP47) serves as an endoplasmic reticulum residing collagen-specific chaperone and plays an important role in collagen biosynthesis and structural assembly. HSP47 is encoded by the SERPINH1 gene, which is located on chromosome 11q13.5, one of the most frequently amplified regions in human cancers. The expression of HSP47 is regulated by multiple cellular factors, including cytokines, transcription factors, microRNAs, and circular RNAs. HSP47 is frequently upregulated in a variety of cancers and plays an important role in tumor progression. HSP47 promotes tumor stemness, angiogenesis, growth, epithelial-mesenchymal transition, and metastatic capacity. HSP47 also regulates the efficacy of tumor therapies, such as chemotherapy, radiotherapy, and immunotherapy. Inhibition of HSP47 expression has antitumor effects, suggesting that targeting HSP47 is a feasible strategy for cancer treatment. In this review, we highlight the function and expression of regulatory mechanisms of HSP47 in cancer progression and point out the potential development of therapeutic strategies in targeting HSP47 in the future.

HSP47 in human diseases: Navigating pathophysiology, diagnosis and therapy

Heat shock protein 47 (HSP47) is a chaperone protein responsible for regulating collagen maturation and transport, directly impacting collagen synthesis levels. Aberrant HSP47 expression or malfunction has been associated with collagen-related disorders, most notably fibrosis. Recent reports have uncovered new functions of HSP47 in various cellular processes. Hsp47 dysregulation in these alternative roles has been linked to various diseases, such as cancer, autoimmune and neurodegenerative disorders, thereby highlighting its potential as both a diagnostic biomarker and a therapeutic target. In this review, we discuss the pathophysiological roles of HSP47 in human diseases, its potential as a diagnostic tool, clinical screening techniques and its role as a target for therapeutic interventions.

Readers of RNA Modification in Cancer and Their Anticancer Inhibitors

Cancer treatment has always been a challenge for humanity. The inadequacies of current technologies underscore the limitations of our efforts against this disease. Nevertheless, the advent of targeted therapy has introduced a promising avenue, furnishing us with more efficacious tools. Consequently, researchers have turned their attention toward epigenetics, offering a novel perspective in this realm. The investigation of epigenetics has brought RNA readers to the forefront, as they play pivotal roles in recognizing and regulating RNA functions. Recently, the development of inhibitors targeting these RNA readers has emerged as a focal point in research and holds promise for further strides in targeted therapy. In this review, we comprehensively summarize various types of inhibitors targeting RNA readers, including non-coding RNA (ncRNA) inhibitors, small-molecule inhibitors, and other potential inhibitors. We systematically elucidate their mechanisms in suppressing cancer progression by inhibiting readers, aiming to present inhibitors of readers at the current stage and provide more insights into the development of anticancer drugs.

ESRP1-mediated biogenesis of circPTPN12 inhibits hepatocellular carcinoma progression by PDLIM2/ NF-κB pathway

BACKGROUND

Emerging evidence indicates the pivotal involvement of circular RNAs (circRNAs) in cancer initiation and progression. Understanding the functions and underlying mechanisms of circRNAs in tumor development holds promise for uncovering novel diagnostic indicators and therapeutic targets. In this study, our focus was to elucidate the function and regulatory mechanism of hsa-circ-0003764 in hepatocellular carcinoma (HCC).

METHODS

A newly discovered hsa-circ-0003764 (circPTPN12) was identified from the circbase database. QRT-PCR analysis was utilized to assess the expression levels of hsa-circ-0003764 in both HCC tissues and cells. We conducted in vitro and in vivo experiments to examine the impact of circPTPN12 on the proliferation and apoptosis of HCC cells. Additionally, RNA-sequencing, RNA immunoprecipitation, biotin-coupled probe pull-down assays, and FISH were employed to confirm and establish the relationship between hsa-circ-0003764, PDLIM2, OTUD6B, P65, and ESRP1.

RESULTS

In HCC, the downregulation of circPTPN12 was associated with an unfavorable prognosis. CircPTPN12 exhibited suppressive effects on the proliferation of HCC cells both in vitro and in vivo. Mechanistically, RNA sequencing assays unveiled the NF-κB signaling pathway as a targeted pathway of circPTPN12. Functionally, circPTPN12 was found to interact with the PDZ domain of PDLIM2, facilitating the ubiquitination of P65. Furthermore, circPTPN12 bolstered the assembly of the PDLIM2/OTUD6B complex by promoting the deubiquitination of PDLIM2. ESRP1 was identified to bind to pre-PTPN12, thereby fostering the generation of circPTPN12.

CONCLUSIONS

Collectively, our findings indicate the involvement of circPTPN12 in modulating PDLIM2 function, influencing HCC progression. The identified ESRP1/circPTPN12/PDLIM2/NF-κB axis shows promise as a novel therapeutic target in the context of HCC.

Hsa_circ_0001741 Suppresses Ovarian Cancer Cell Proliferations Through Adsorption of miR-188-5p and Promotion of FOXN2 Expression

Ovarian cancer (OC) is among several general malignant gynecological cancers associated with high mortality rates on a global scale. Earlier investigations have revealed a critical role of circular RNAs (circRNAs) in OC development, which is a new class of endogenous non-coding RNA (ncRNA) that reported to mediate progression of diverse tumor types. At present, the precise involvement of circRNAs and associated regulatory mechanisms in OC remain unknown. In this study, hsa_circ_0001741 expression patterns in OC cells and tissues were tested. The underlying regulatory pathways and targets were further explored with the aid of bioinformatics, luciferase reporter, 5-ethynyl-2'-deoxyuridine (EdU) and cell counting kit-8 (CCK-8) analyses. Further investigation of the hsa_circ_0001741 effects on tumor growth in vivo revealed abnormal circRNA expression in OC. hsa_circ_0001741 expression reduced in OC cells and tissues, indicative of activity in OC progression. hsa_circ_0001741 upregulation resulted in OC proliferation inhibitions. The luciferase reporter outputs verified miR-188-5p and FOXN2 as hsa_circ_0001741 downstream targets. FOXN2 silencing or miR-188-5p upregulations reversed inhibitory effects regarding hsa_circ_0001741 on OC cell proliferation. Therefore our data suggested that hsa_circ_0001741 upregulation inhibited proliferation of OC through modulatory effects on miR-188-5p/FOXN2 signaling.

SERPINH1 promoted the proliferation and metastasis of colorectal cancer by activating PI3K/Akt/mTOR signaling pathway

BACKGROUND

Serpin peptidase inhibitor clade H member 1 (SERPINH1) was initially recognized as an oncogene implicated in various human malignancies. Nevertheless, the clinical relevance and functional implications of SERPINH1 in colorectal cancer (CRC) remain largely elusive.

AIM

To investigate the effects of SERPINH1 on CRC cells and its specific mechanism.

METHODS

Quantitative real-time polymerase chain reaction, western blotting analysis, The Cancer Genome Atlas data mining and immunohistochemistry were employed to examine SERPINH1 expression in CRC cell lines and tissues. A series of in-vitro assays were performed to demonstrate the function of SERPINH1 and its possible mechanisms in CRC.

RESULTS

SERPINH1 demonstrated elevated expression levels in both CRC cells and tissues, manifested at both mRNA and protein tiers. Elevated SERPINH1 levels correlated closely with advanced T stage, lymph node involvement, and distant metastasis, exhibiting a significant association with poorer overall survival among CRC patients. Subsequent investigations unveiled that SERPINH1 overexpression notably bolstered CRC cell proliferation, invasion, and migration in vitro, while conversely, SERPINH1 knockdown elicited the opposite effects. Gene set enrichment analysis underscored a correlation between SERPINH1 upregulation and genes associated with cell cycle regulation. Our findings underscored the capacity of heightened SERPINH1 levels to expedite G1/S phase cell cycle progression via phosphatidylinositol 3-kinase/AKT/mechanistic target of rapamycin pathway activation, thereby facilitating CRC cell invasion and migration.

CONCLUSION

These findings imply a crucial involvement of SERPINH1 in the advancement and escalation of CRC, potentially positioning it as a novel candidate for prognostic assessment and therapeutic intervention in CRC management.

IGF2BP2 regulates the inflammation of fibroblast-like synoviocytes via GSTM5 in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease with an unknown etiology. RA cannot be fully cured and requires lengthy treatment, imposing a significant burden on both individuals and society. Due to the lack of specific drugs available for treating RA, exploring a key new therapeutic target for RA is currently an important task. Activated fibroblast-like synoviocytes (FLSs) play a crucial role in the progression of RA, which release interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α resulting in abnormal inflammatory reaction in the synovium. A previous study has highlighted the correlation of m6A reader insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) with inflammation-related diseases in human. However, the role of IGF2BP2 in the inflammatory reaction of FLSs during RA progression has not been assessed. In this study, IGF2BP2 expression was decreased in the synovial tissues of RA patients and collagen-induced arthritis (CIA) rats. Intra-articular injection of an adeno-associated virus (AAV) vector overexpressing IGF2BP2 relieved paw swelling, synovial hyperplasia and cartilage destruction in CIA rats. IGF2BP2 overexpression also inhibited lipopolysaccharide (LPS)-mediated RA fibroblast-like synoviocytes (RA-FLSs) migration and invasion accompanied by a decreased level of inflammatory factors in vitro. Conversely, IGF2BP2 suppression promoted RA-FLSs migration and invasion with an elevated level of inflammatory factors in vitro. The sequencing result showed that glutathione S-transferase Mu 5 (GSTM5), a key antioxidant gene, was the target mRNA of IGF2BP2. Further experiments demonstrated that IGF2BP2 strengthened the stability of GSTM5 mRNA, leading to weakened inflammatory reaction and reduced expression of matrix metalloproteinase 9 and 13 (MMP9, MMP13). Therefore, IGF2BP2-GSTM5 axis may represent a potential therapeutic target for RA treatment.

Mesenchymal stromal/stem cells promote intestinal epithelium regeneration after chemotherapy-induced damage

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment for leukemia and a range of non-malignant disorders. The success of the therapy is hampered by occurrence of acute graft-versus-host disease (aGvHD); an inflammatory response damaging recipient organs, with gut, liver, and skin being the most susceptible. Intestinal GvHD injury is often a life-threatening complication in patients unresponsive to steroid treatment. Allogeneic mesenchymal stromal/stem cell (MSC) infusions are a promising potential treatment for steroid-resistant aGvHD. Data from our institution and others demonstrate rescue of approximately 40-50% of aGvHD patients with MSCs in Phase I, II studies and minor side effects. Although promising, better understanding of MSC mode of action and patient response to MSC-based therapy is essential to improve this lifesaving treatment.

METHODS

Single cell human small intestine organoids were embedded in Matrigel, grown for 5 days and treated with busulfan for 48 h. Organoids damaged by treatment with busulfan or control organoids were co-cultured with 5000, 10,000, and 50,000 MSCs for 24 h, 48 h or 7 days and the analyses such as surface area determination, proliferation and apoptosis assessment, RNA sequencing and proteomics were performed.

RESULTS

Here, we developed a 3D co-culture model of human small intestinal organoids and MSCs, which allows to study the regenerative effects of MSCs on intestinal epithelium in a more physiologically relevant setting than existing in vitro systems. Using this model we mimicked chemotherapy-mediated damage of the intestinal epithelium. The treatment with busulfan, the chemotherapeutic commonly used as conditioning regiment before the HSCT, affected pathways regulating epithelial to mesenchymal transition, proliferation, and apoptosis in small intestinal organoids, as shown by transcriptomic and proteomic analysis. The co-culture of busulfan-treated intestinal organoids with MSCs reversed the effects of busulfan on the transcriptome and proteome of intestinal epithelium, which we also confirmed by functional evaluation of proliferation and apoptosis.

CONCLUSIONS

Collectively, we demonstrate that our in vitro co-culture system is a new valuable tool to facilitate the investigation of the molecular mechanisms behind the therapeutic effects of MSCs on damaged intestinal epithelium. This could benefit further optimization of the use of MSCs in HSCT patients.

RNA-binding protein IGF2BP2 suppresses metastasis of clear cell renal cell carcinoma by enhancing CKB mRNA stability and expression

Clear cell renal cell carcinoma (ccRCC) is the most prevalent kidney cancer, with a highly aggressive phenotype and poor prognosis. RNA binding proteins (RBPs) play crucial roles in post-transcriptional gene regulation and have been implicated in tumorigenesis. RBPs have the potential to become a new therapeutic target for ccRCC. In this study, we screened and validated that insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) as an RBP, was down-regulated in ccRCC tissues and cell lines. Functionally, we verified that IGF2BP2 significantly suppressed the migration and invasion ability of ccRCC in vitro and in vivo. Mechanistically, RIP-seq and actinomycin D experiments results showed that IGF2BP2 enhanced the expression of Creatine Kinase B (CKB) by binding to CKB mRNA and enhancing its mRNA stability. Thus, IGF2BP2 inhibited ccRCC metastasis through enhancing the expression of CKB. Taken together, these finding suggests that IGF2BP2 is a novel metastasis suppressor of ccRCC and may serve as a potential therapeutic target.

Non-coding RNA-Mediated N6-Methyladenosine (m6A) deposition: A pivotal regulator of cancer, impacting key signaling pathways in carcinogenesis and therapy response

The emergence of RNA modifications has recently been considered as critical post-transcriptional regulations which governed gene expression. N6-methyladenosine (m6A) modification is the most abundant type of RNA modification which is mediated by three distinct classes of proteins called m6A writers, readers, and erasers. Accumulating evidence has been made in understanding the role of m6A modification of non-coding RNAs (ncRNAs) in cancer. Importantly, aberrant expression of ncRNAs and m6A regulators has been elucidated in various cancers. As the key role of ncRNAs in regulation of cancer hallmarks is well accepted now, it could be accepted that m6A modification of ncRNAs could affect cancer progression. The present review intended to discuss the latest knowledge and importance of m6A epigenetic regulation of ncRNAs including mircoRNAs, long non-coding RNAs, and circular RNAs, and their interaction in the context of cancer. Moreover, the current insight into the underlying mechanisms of therapy resistance and also immune response and escape mediated by m6A regulators and ncRNAs are discussed.

A novel peptide PDHK1-241aa encoded by circPDHK1 promotes ccRCC progression via interacting with PPP1CA to inhibit AKT dephosphorylation and activate the AKT-mTOR signaling pathway

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is the most prevalent kidney cancer with high aggressive phenotype and poor prognosis. Accumulating evidence suggests that circRNAs have been identified as pivotal mediators in cancers. However, the role of circRNAs in ccRCC progression remains elusive.

METHODS

The differentially expressed circRNAs in 4 paired human ccRCC and adjacent noncancerous tissues ccRCC were screened using circRNA microarrays and the candidate target was selected based on circRNA expression level using weighted gene correlation network analysis (WGCNA) and the gene expression omnibus (GEO) database. CircPDHK1 expression in ccRCC and adjacent noncancerous tissues (n = 148) were evaluated along with clinically relevant information. RT-qPCR, RNase R digestion, and actinomycin D (ActD) stability test were conducted to identify the characteristics of circPDHK1. The subcellular distribution of circPDHK1 was analyzed by subcellular fractionation assay and fluorescence in situ hybridization (FISH). Immunoprecipitation-mass spectrometry (IP-MS) and immunofluorescence (IF) were employed to evaluate the protein-coding ability of circPDHK1. ccRCC cells were transfected with siRNAs, plasmids or lentivirus approach, and cell proliferation, migration and invasion, as well as tumorigenesis and metastasis in nude mice were assessed to clarify the functional roles of circPDHK1 and its encoded peptide PDHK1-241aa. RNA-sequencing, western blot analysis, immunoprecipitation (IP) and chromatin immunoprecipitation (ChIP) assays were further employed to identify the underlying mechanisms regulated by PDHK1-241aa.

RESULTS

CircPDHK1 was upregulated in ccRCC tissues and closely related to WHO/ISUP stage, T stage, distant metastasis, VHL mutation and Ki-67 levels. CircPDHK1 had a functional internal ribosome entry site (IRES) and encoded a novel peptide PDHK1-241aa. Functionally, we confirmed that PDHK1-241aa and not the circPDHK1 promoted the proliferation, migration and invasion of ccRCC. Mechanistically, circPDHK1 was activated by HIF-2A at the transcriptional level. PDHK1-241aa was upregulated and interacted with PPP1CA, causing the relocation of PPP1CA to the nucleus. This thereby inhibited AKT dephosphorylation and activated the AKT-mTOR signaling pathway.

CONCLUSIONS

Our data indicated that circPDHK1-encoded PDHK1-241aa promotes ccRCC progression by interacting with PPP1CA to inhibit AKT dephosphorylation. This study provides novel insights into the multiplicity of circRNAs and highlights the potential use of circPDHK1 or PDHK1-241aa as a therapeutic target for ccRCC.

CircMAST1 inhibits cervical cancer progression by hindering the N4-acetylcytidine modification of YAP mRNA

BACKGROUND

Cervical cancer (CCa) is the fourth most common cancer among females, with high incidence and mortality rates. Circular RNAs (circRNAs) are key regulators of various biological processes in cancer. However, the biological role of circRNAs in cervical cancer (CCa) remains largely unknown. This study aimed to elucidate the role of circMAST1 in CCa.

METHODS

CircRNAs related to CCa progression were identified via a circRNA microarray. The relationship between circMAST1 levels and clinicopathological features of CCa was evaluated using the clinical specimens and data of 131 patients with CCa. In vivo and in vitro experiments, including xenograft animal models, cell proliferation assay, transwell assay, RNA pull-down assay, whole-transcriptome sequencing, RIP assay, and RNA-FISH, were performed to investigate the effects of circMAST1 on the malignant behavior of CCa.

RESULTS

CircMAST1 was significantly downregulated in CCa tissues, and low expression of CircMAST1 was correlated with a poor prognosis. Moreover, our results demonstrated that circMAST1 inhibited tumor growth and lymph node metastasis of CCa. Mechanistically, circMAST1 competitively sequestered N-acetyltransferase 10 (NAT10) and hindered Yes-associated protein (YAP) mRNA ac4C modification to promote its degradation and inhibit tumor progression in CCa.

CONCLUSIONS

CircMAST1 plays a major suppressive role in the tumor growth and metastasis of CCa. In particular, circMAST1 can serve as a potential biomarker and novel target for CCa.

Dysregulated ANLN reveals immune cell landscape and promotes carcinogenesis by regulating the PI3K/Akt/mTOR pathway in clear cell renal cell carcinoma

Background

Abnormal anillin (ANLN) expression has been observed in multiple tumours and is closely associated with patient prognosis and clinical features. In this study, we systematically elucidated the clinical significance and biological roles of ANLN in patients with clear cell renal cell carcinoma (ccRCC).

Methods

We obtained transcriptome and clinical data of patients with ccRCC from public databases. Multi-omics data and clinical samples were combined to analyse the correlation between ANLN expression and the clinical characteristics of patients with renal cancer. Additionally, the immune cell landscape of ANLN expression was evaluated using different immune algorithms in the tumour microenvironment. The tumour-promoting potential of ANLN was confirmed using in vitro assays, including CCK8 and Transwell assays.

Results

Bioinformatics analysis showed that ANLN is over-expressed in patients with ccRCC, as validated by clinical samples. Publicly available clinical data suggest that high ANLN expression may indicate poor outcomes in patients with ccRCC. Moreover, biological function analysis revealed a marked enrichment of the cell cycle and PI3K-Akt pathways. The distribution of immune cells, particularly M2 macrophages, differed in patients with ccRCC. Furthermore, ANLN silencing inhibited the proliferation, migration, and invasion of renal cancer cells in vitro. After ANLN expression was knocked down in 786-O cells, the protein levels of important PI3K signalling pathway components, including PI3K, Akt, and mTOR, drastically decreased.

Conclusions

These findings suggest that ANLN is dysregulated in renal cancer tissues and promotes tumour progression by activating the PI3K/Akt/mTOR signalling pathway.

RNA Binding Protein PTBP1 Promotes the Metastasis of Gastric Cancer by Stabilizing PGK1 mRNA

Gastric cancer (GC) is the most common type of malignant tumor within the gastrointestinal tract, and GC metastasis is associated with poor prognosis. Polypyrimidine tract binding protein 1 (PTBP1) is an RNA-binding protein implicated in various types of tumor development and metastasis. However, the role of PTBP1 in GC metastasis remains elusive. In this study, we verified that PTBP1 was upregulated in GC tissues and cell lines, and higher PTBP1 level was associated with poorer prognosis. It was shown that PTBP1 knockdown in vitro inhibited GC cell migration, whereas PTBP1 overexpression promoted the migration of GC cells. In vivo, the knockdown of PTBP1 notably reduced both the size and occurrence of metastatic nodules in a nude mice liver metastasis model. We identified phosphoglycerate kinase 1 (PGK1) as a downstream target of PTBP1 and found that PTBP1 increased the stability of PGK1 by directly binding to its mRNA. Furthermore, the PGK1/SNAIL axis could be required for PTBP1's function in the promotion of GC cell migration. These discoveries suggest that PTBP1 could be a promising therapeutic target for GC.

Identification of circATG9A as a novel biomarker for renal cell carcinoma

The incidence and mortality rates of renal cell carcinoma (RCC) have rapidly increased worldwide. To gain new insights into the regulatory role of circular RNAs (circRNAs) in RCC progression, we conducted RNA sequencing on three pairs of ccRCC and adjacent normal tissues. RT-PCR was utilized to analyze RNA expression. We investigated the effects of circATG9A on RCC cells through various assays including CCK-8, Transwell, wound healing, and colony formation assays. Furthermore, we employed FISH, RNA pull-down, luciferase reporter, and RIP assays to elucidate the mechanism by which circATG9A regulates RCC. Ultimately, we identified 118 differentially expressed circRNAs in RCC, including a novel circRNA, circATG9A, which was found to promote RCC progression both in vitro and in vivo. Moreover, mRNA sequencing, western blotting, and rescue experiments indicated that TRPM3 is the target of circATG9A in RCC progression. Bioinformatic analysis, RNA pull-down, FISH, and RIP assays suggested that circATG9A regulates TRPM3 expression by acting as a sponge for miR-497-5p. Finally, Western blotting revealed that circATG9A promotes the epithelial-mesenchymal transition (EMT) process through the Wnt/β-catenin signaling pathway. Our findings demonstrate that circATG9A is a novel circRNA upregulated in RCC that plays a crucial role in the EMT process through the miR-497-5p/TRPM3/Wnt/β-catenin axis. These results suggest that circATG9A could be a promising target for RCC prognosis and therapy.

Circ-Plod2 destabilizes Mpo mRNA by binding to IGF2BP2 to promote osteogenic differentiation of bone marrow mesenchymal stem cells

Osteogenic differentiation, proliferation, and/or apoptosis of bone marrow mesenchymal stem cells (BMSCs) are involved in the progression of postmenopausal osteoporosis (PMO). However, circular RNA (circRNA)-mediated changes in the cellular function of BMSCs in PMO are still unclear. This study revealed the excellent ability of circ-Plod2 to promote osteogenic differentiation of BMSCs and its molecular mechanisms. In this study, ovariectomized (OVX) rats and control (Sham) rats were used to simulate PMO. Initially, we found that the expression of circ-Plod2 in OVX BMSCs is down-regulated and the expression of the Mpo gene is up-regulated by sequencing and verification. Further, we confirmed that circ-Plod2 is located in the cytoplasm and belongs to exon-type circRNA. Interestingly, circ-Plod2 promotes Mpo-dependent osteogenic differentiation of BMSCs without affecting proliferation, apoptosis, adipogenic differentiation, or chondrogenic differentiation of BMSCs. Mechanistically, we demonstrated that circ-Plod2 specifically binds IGF2BP2 to form an RNA-protein complex that destabilizes Mpo mRNA. Overexpression of circ-Plod2 in the bone marrow cavity effectively alleviated osteoporosis in OVX rats and inhibited the expression of MPO in BMSCs. Together, this study reveals that circ-Plod2 destabilizes Mpo mRNA by binding to IGF2BP2 to promote osteogenic differentiation of BMSCs to alleviate osteoporosis. The findings of this study may provide biomarkers for the diagnosis of PMO, and may also provide potential strategies for the clinical treatment of PMO.

The role of circRNAs in regulation of drug resistance in ovarian cancer

Ovarian cancer is one of the female reproductive system tumors. Chemotherapy is used for advanced ovarian cancer patients; however, drug resistance is a pivotal cause of chemotherapeutic failure. Hence, it is critical to explore the molecular mechanisms of drug resistance of ovarian cancer cells and to ameliorate chemoresistance. Noncoding RNAs (ncRNAs) have been identified to critically participate in drug sensitivity in a variety of human cancers, including ovarian cancer. Among ncRNAs, circRNAs sponge miRNAs and prevent miRNAs from regulation of their target mRNAs. CircRNAs can interact with DNA or proteins to modulate gene expression. In this review, we briefly describe the biological functions of circRNAs in the development and progression of ovarian cancer. Moreover, we discuss the underneath regulatory molecular mechanisms of circRNAs on governing drug resistance in ovarian cancer. Furthermore, we mention the novel strategies to overcome drug resistance via targeting circRNAs in ovarian cancer. Due to that circRNAs play a key role in modulation of drug resistance in ovarian cancer, targeting circRNAs could be a novel approach for attenuation of chemoresistance in ovarian cancer.

m6A and m5C modification of GPX4 facilitates anticancer immunity via STING activation

Cancer immunotherapy is arguably the most rapidly advancing realm of cancer treatment. Glutathione peroxidase 4 (GPX4) has emerged as the vital enzyme to prevent lipid peroxidation and maintain cellular redox homeostasis. However, the mechanism of GPX4 in the regulation of cancer immunotherapy of colon adenocarcinoma (COAD) are incompletely understood. In pan-cancer analysis, we found that GPX4 showed remarkably upregulated expression and exhibited significant association with overall survival in multiple cancer types, especially COAD. Furthermore, upregulated GPX4 expression was positively correlated with increased immune cells infiltration and enhanced expression of immunomodulators. Mechanistically, RBM15B- and IGFBP2-mediated N6-methyladenosine (m6A) modification and NSUN5-mediated 5-methylcytosine (m5C) modification of GPX4 facilitated anticancer immunity via activation of cyclic GMP-AMP synthase (cGAS)-stimulator of interferon (STING) signaling by maintaining redox homeostasis in COAD. The risk model and nomogram model constructed based on the GPX4-derived genes further confirmed the prognostic and treatment-guiding value of GPX4. In all, our study demonstrated that m6A and m5C modification of GPX4 may be a promising target for cancer immunotherapy via activating the cGAS-STING signaling pathway in COAD.

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.

Comprehensive analysis reveals the involvement of hsa_circ_0037858/miR-5000-3p/FMR1 axis in malignant metastasis of clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is a heterogenous tumor with high metastatic potential. Circular RNAs (circRNAs) play key roles in cancer initiation and progression. However, the knowledge of circRNA in ccRCC metastasis is still inadequate. In this study, a series of in silico analyses and experimental validation were employed. The differentially expressed circRNAs (DECs) between ccRCC and normal or metastatic ccRCC tissues were screened out using GEO2R. Hsa_circ_0037858 was identified as the most potential circRNA related to ccRCC metastasis, which was significantly downregulated in ccRCC compared with normal and was also markedly decreased in metastatic ccRCC compared with primary ccRCC. The structural pattern of hsa_circ_0037858 presented several microRNA response elements and four binding miRNAs of hsa_circ_0037858, consisting of miR-3064-5p, miR-6504-5p, miR-345-5p and miR-5000-3p, were predicted using CSCD and starBase. Among them, miR-5000-3p with high expression and statistical diagnostic value was considered as the most potential binding miRNA of hsa_circ_0037858. Then, protein-protein interaction analysis revealed a close linkage among the target genes of miR-5000-3p and the top 20 hub genes among them were identified. Based on node degree, MYC, RHOA, NCL, FMR1 and AGO1 were ranked as the top 5 hub genes. FMR1 was identified as the most potential downstream gene of hsa_circ_0037858/miR-5000-3p axis according to expression, prognosis and correlation analysis. Moreover, hsa_circ_0037858 suppressed in vitro metastasis and enhanced FMR1 expression in ccRCC, which could be markedly reversed by introduction of miR-5000-3p overexpression. Collectively, we elucidated a potential hsa_circ_0037858/miR-5000-3p/FMR1 axis involved in ccRCC metastasis.

The emerging roles and mechanism of N6-methyladenosine (m6A) modifications in urologic tumours progression

Prostate cancer (PCa), bladder cancer (BC), and renal cell cancer (RCC) are the most common urologic tumours in males. N6-methyladenosine (m⁶A), adenosine N6 methylation, is the most prevalent RNA modification in mammals. Increasing evidence suggests that m⁶A plays a crucial role in cancer development. In this review, we comprehensively analyzed the influence of m⁶A methylation on Prostate cancer, bladder cancer, and renal cell cancer and the relationship between the expression of relevant regulatory factors and their development and occurrence, which provides new insights and approaches for the early clinical diagnosis and targeted therapy of urologic malignancies.

CircZBTB44 promotes renal carcinoma progression by stabilizing HK3 mRNA structure

CircZBTB44 (hsa_circ_0002484) has been identified to be upregulated in renal cell carcinoma (RCC) tissues, while its role and contribution in RCC remain elusive. We confirmed the overexpression of circZBTB44 in RCC cells compared to normal kidney cell HK-2. CircZBTB44 knockdown suppressed the viability, proliferation, and migration of RCC cells and inhibited tumorigenesis in xenograft mouse models. Heterogeneous Nuclear Ribonucleoprotein C (HNRNPC) and Insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3) are two RNA binding proteins of circZBTB44. HNRNPC facilitated the translocation of circZBTB44 from nuclei to cytoplasm via m6A modification, facilitating the interaction of IGF2BP3 and circZBTB44 in the cytoplasm of RCC cells. Furthermore, circZBTB44 upregulated Hexokinase 3 (HK3) expression by binding to IGF2BP3 in RCC cells. HK3 exerted oncogenic effects on RCC cell malignant behaviors and tumor growth. In the co-culture of RCC cells with macrophages, circZBTB44 promoted M2 polarization of macrophages by up-regulating HK3. In summary, HNRNPC mediated circZBTB44 interaction with IGF2BP3 to up-regulate HK3, promoting the proliferation and migration of RCC cells in vitro and tumorigenesis in vivo. The results of the study shed new light on the targeted therapy of RCC.

By using machine learning and in vitro testing, SERPINH1 functions as a novel tumorigenic and immunogenic gene and predicts immunotherapy response in osteosarcoma

Introduction

The most prevalent bone tumor with a relatively high level of aggressiveness and malignancy is osteosarcoma. The characteristics of the serpin family in osteosarcoma have not been defined.

Methods

In this study, the predictive significance of the serpin superfamily was investigated in the osteosarcoma and Gene Expression Omnibus (GEO) databases from The Cancer Genome Atlas (TCGA).

Results

It was discovered that SERPINH1 is a significant biological marker in osteosarcoma. According to the CCK-8, EdU, and Transwell assays as well as the IHC assay, SERPINH1 may promote osteosarcoma proliferation and migration. It is also more expressed in tumor samples than in healthy samples. SERPINH1 might forecast the effects of immunotherapy. Additionally, immune cells are interacted with through checkpoint, cytokine, and growth factor pathways in osteosarcomas with high SERPINH1 levels. The biological function, immunological characteristics, and treatment response (immunotherapy and chemotherapy responses) of patients with osteosarcoma were successfully predicted using a model related to SERPINH1. SERPINH1 and the SERPINH1-related score predict ferroptosis/pyroptosis/apoptosis/necroptosis in osteosarcoma.

Discussion

The SERPINH1-related score was an effective method for identifying osteosarcoma patients who would respond to immunotherapy and chemotherapy, as well as for predicting the survival outcomes of such patients.

VHL-HIF-2α axis-induced SEMA6A upregulation stabilized β-catenin to drive clear cell renal cell carcinoma progression

SEMA6A is a multifunctional transmembrane semaphorin protein that participates in various cellular processes, including axon guidance, cell migration, and cancer progression. However, the role of SEMA6A in clear cell renal cell carcinoma (ccRCC) is unclear. Based on high-throughput sequencing data, here we report that SEMA6A is a novel target gene of the VHL-HIF-2α axis and overexpressed in ccRCC. Chromatin immunoprecipitation and reporter assays revealed that HIF-2α directly activated SEMA6A transcription in hypoxic ccRCC cells. Wnt/β-catenin pathway activation is correlated with the expression of SEMA6A in ccRCC; the latter physically interacted with SEC62 and promoted ccRCC progression through SEC62-dependent β-catenin stabilization and activation. Depletion of SEMA6A impaired HIF-2α-induced Wnt/β-catenin pathway activation and led to defective ccRCC cell proliferation both in vitro and in vivo. SEMA6A overexpression promoted the malignant phenotypes of ccRCC, which was reversed by SEC62 depletion. Collectively, this study revealed a potential role for VHL-HIF-2α-SEMA6A-SEC62 axis in the activation of Wnt/β-catenin pathway. Thus, SEMA6A may act as a potential therapeutic target, especially in VHL-deficient ccRCC.

The Involvement of Insulin-Like Growth Factor 2 Messenger Ribonucleic Acid-Binding Protein 2 in the Regulation of the Expression of Breast Cancer-Related Genes

Aim

This study investigated the role and mechanism of insulin-like growth factor 2-IGF2BP2 in breast cancer.

Methods

IGF2BP2 is overexpressed in MDA-MB-231 human breast cancer cells. Thus, RNA sequencing was used to analyze the differentially expressed genes, Cell Counting Kit-8 was used to detect cell proliferation, and a Transwell assay was used to assess cell invasion. Following on from the RNA sequencing results, Interferon-induced protein with tetratricopeptide repeats 2 (IFIT2), chemokine C-C motif ligand 20 (CCL20), chemokine C-C motif ligand 5 (CCL5), and chemokine C-X-C motif ligand 10 (CXCL10) regulated by IGF2BP2 were subjected to real-time reverse transcriptase-polymerase chain reaction verification.

Results

After IGF2BP2 overexpression, 67 genes were up-regulated, and 87 genes were down-regulated. The gene with the most significant up-regulation was homeobox protein 1 (PROX1), and the gene with the most significant down-regulation was Acidic β-crystallin 4 (CRYBA4). The most enriched gene ontology (GO) terms of up-regulated differentially expressed genes are protein binding and cell membrane and of down-regulated differentially expressed genes they are ion binding, cytoplasm, and response to virus. Kyoto Encyclopedia of Genes and Genomes analysis showed that the up-regulated differential genes were mainly enriched in protein processing, the endoplasmic reticulum, and the regulation of actin cytoskeleton, while down-regulated differential genes were mainly enriched in rheumatoid arthritis, chemokine signaling pathways, toll-like receptor signaling pathways, tumor necrosis factor signaling pathways, cytokine-cytokine receptor interaction, and Notch signaling pathways. IGF2BP2 overexpression significantly promoted the proliferation and invasion of breast cancer cells (P < 0.01). Compared with the control group, the IGF2BP2 overexpression group had significantly increased expressions of IFIT2, CCL20, and CXCL10 (P < 0.05).

Conclusion

IGF2BP2 may promote the invasion and proliferation of human breast cancer cells by up-regulating breast cancer-related genes, such as IFIT2, CCL20, and CXCL10.