MafF Is Regulated via the circ-ITCH/miR-224-5p Axis and Acts as a Tumor Suppressor in Hepatocellular Carcinoma

N6-Methyladenosine reader HNRNPC-mediated downregulation of circITCH prevents miR-224-3p sequestering and contributes to tumorigenesis in nasopharyngeal carcinoma

BACKGROUND

N6-Methyladenosine (m6A) RNA methylation modulators are implicated in nasopharyngeal carcinoma (NPC). Circular RNAs (circRNAs) stimulate/inhibit the development of NPC by sponging microRNAs (miRNAs). Herein, m6A modifications affecting the circRNA/miRNA axis in NPC were explored.

METHODS

Twenty prognostic m6A RNA methylation regulators were identified from 504 head/neck squamous cell carcinoma and 44 normal samples from The Cancer Genome Atlas (TCGA). Differentially expressed miRNAs were screened from the TCGA and Gene Expression Omnibus (GEO) databases. RNA-binding protein (RBP)-circRNA and circRNA-miRNA interactive pairs were verified using RBPmap and RNAhybrid, respectively. The RBP/circRNA/miRNA network was constructed using Cytoscape. Furthermore, CircITCH (hsa_circ_00059948), HNRNPC, and miR-224-3p expressions were detected by western blotting and quantitative polymerase chain reaction. The role of circITCH in NPC was examined using apoptosis, scratch wound healing, transwell invasion, and cell counting kit-8 assays. Finally, CircITCH-miR-224-3p and circITCH-HNRNPC interactions were assessed by dual-luciferase reporter and RNA-immunoprecipitation (RIP) assays, respectively.

RESULTS

Bioinformatics analysis revealed that high pathological grade, late-stage tumors, and low survival were associated with increased HNRNPC expression. MiR-224-3p was upregulated in NPC and sequestered by circITCH. Construction of the RBP/circRNA/miRNA network highlighted the HNRNPC/circITCH/miR-224-3p axis. In vitro experiments demonstrated decreased circITCH expression and increased HNRNPC and miR-224-3p expressions in NPC. In NPC cells overexpressing circITCH, HNRNPC and miR-224-3p expressions were significantly decreased. Dual-luciferase assays demonstrated a targeting relationship between circITCH and miR-224-3p, and RIP assays demonstrated interaction of HNRNPC targets with circITCH.

CONCLUSION

CircITCH overexpression inhibited NPC progression by sequestering miR-224-3p, and HNRNPC reduced circITCH expression through direct interaction.

Theaflavin-3,3'-Digallate Protects Liver and Kidney Functions in Diabetic Rats by Up-Regulating Circ-ITCH and Nrf2 Signaling Pathway

Theaflavin-3,3'-digallate (TFDG) in black tea has a strong antioxidant capacity. However, its effect on diabetic liver and kidney injury and the underlying mechanisms remain unclear. In the present study, our findings indicated that TFDG administration effectively lowers the fasting blood glucose and serum lipid concentrations and enhances the functionality and cellular architecture of the liver and kidney in rats with diabetes. The data also showed that TFDG mitigates oxidative harm in the liver and kidney of rats afflicted with diabetes. Additionally, metformin combined with TFDG was significantly more effective in reducing blood glucose and oxidative stress. Further studies suggested that TFDG upregulates the Nrf2 signal pathway and circ-ITCH (hsa_circ_0001141) expression. Silencing of circ-ITCH by transfection of the interfering plasmid apparently reduces the effects of TFDG on the Nrf2 signal pathway and oxidative stress in high-glucose-treated hepatic and renal cells. In conclusion, the present study highlights the great potential of TFDG in ameliorating diabetic liver and kidney injury by up-regulating circ-ITCH to promote the Nrf2 signal pathway and provides a potential option for the prevention and treatment of diabetic complications.

MAFF confers vulnerability to cisplatin-based and ionizing radiation treatments by modulating ferroptosis and cell cycle progression in lung adenocarcinoma

AIMS

Lung cancer is the leading cause of cancer mortality and lung adenocarcinoma (LUAD) accounts for more than half of all lung cancer cases. Tumor elimination is mostly hindered by drug resistance and the mechanisms remain to be explored in LUAD.

METHODS

CRISPR screens in cell and murine models and single-cell RNA sequencing were conducted, which identified MAF bZIP transcription factor F (MAFF) as a critical factor regulating tumor growth and treatment resistance in LUAD. RNA and ChIP sequencing analyses were performed for transcriptional target expression and specific binding sites of MAFF. Functions of MAFF in inhibiting tumor growth and promoting cisplatin or irradiation efficacy were investigated using cellular and xenograft models.

RESULTS

Patients with lung adenocarcinoma and reduced MAFF expression had worse clinical outcomes. MAFF inhibited tumor cell proliferation by regulating the expression of SLC7A11, CDK6, and CDKN2C, promoting ferroptosis and preventing cell cycle progression from G1 to S. MAFF also conferred tumor cells vulnerable to cisplatin-based or ionizing radiation treatments. MAFF reduction was a final event in the acquisition of cisplatin resistance of LUAD cells. The intracellular cAMP/PKA/CREB1 pathway upregulated MAFF in response to cisplatin-based or ionizing radiation treatments.

CONCLUSIONS

MAFF suppresses tumor growth, and pharmacological agonists targeting MAFF may improve cisplatin or irradiation therapies for lung adenocarcinoma patients.

The role and regulation of Maf proteins in cancer

The Maf proteins (Mafs) belong to basic leucine zipper transcription factors and are members of the activator protein-1 (AP-1) superfamily. There are two subgroups of Mafs: large Mafs and small Mafs, which are involved in a wide range of biological processes, such as the cell cycle, proliferation, oxidative stress, and inflammation. Therefore, dysregulation of Mafs can affect cell fate and is closely associated with diverse diseases. Accumulating evidence has established both large and small Mafs as mediators of tumor development. In this review, we first briefly describe the structure and physiological functions of Mafs. Then we summarize the upstream regulatory mechanisms that control the expression and activity of Mafs. Furthermore, we discuss recent studies on the critical role of Mafs in cancer progression, including cancer proliferation, apoptosis, metastasis, tumor/stroma interaction and angiogenesis. We also review the clinical implications of Mafs, namely their potential possibilities and limitations as biomarkers and therapeutic targets in cancer.

The Role of miRNAs, circRNAs and Their Interactions in Development and Progression of Hepatocellular Carcinoma: An Insilico Approach

Hepatocellular carcinoma (HCC) is a type of malignant tumor. miRNAs are noncoding RNAs and their differential expression patterns are observed in HCC-induced by alcoholism, HBV and HCV infections. By acting as a competing endogenous RNA (ceRNA), circRNA regulates the miRNA function, indirectly controlling the gene expression and leading to HCC progression. In the present study, data mining was performed to screen out all miRNAs and circRNA involved in alcohol, HBV or HCV-induced HCC with statistically significant (≤0.05%) expression levels reported in various studies. Further, the interaction of miRNAs and circRNA was also investigated to explore their role in HCC due to various causative agents. Together, these study data provide a deeper understanding of the circRNA-miRNA regulatory mechanisms in HCC. These screened circRNA, miRNA and their interactions can be used as prognostic biomarkers or therapeutic targets for the treatment of HCC.

Downregulation of circLIFR exerts cancer-promoting effects on hepatocellular carcinoma in vitro

Hepatocellular carcinoma (HCC) is one of the most fatal malignant tumors worldwide. Circular RNAs (circRNAs) are a special type of RNA that lacks the 5′ and 3’ ends. The functional roles of circRNAs in HCC remain largely unknown. Using high-throughput sequencing, we found several differentially expressed circRNAs in HCC tissues compared with nearby normal tissues. Among them, circRNA derived from the LIFR gene, named circLIFR, was significantly downregulated in HCC. Intriguingly, circLIFR overexpression in SK-Hep-1 cells promoted cell growth and invasion. RNA pull-down and mass spectrometry detection revealed circLIFR interacting with TANK binding kinase 1 (TBK1). Anti-TBK1 RIP confirmed the interaction between circLIFR and TBK1. TBK1 is a serine/threonine kinase that regulates several signaling pathways, including the NF-κB pathway. TBK1 inhibitors inhibit NF-κB activation. Overexpression of circLIFR overcame the in-hibitory function of TBK1, resulting in the upregulation of several genes, including MMP13, MMP3, VEGF, and MAPK. This study shows that the downregulation of circLIFR in HCC has a can-cer-promoting effect by interacting with TBK1 to promote the activation of downstream NF-κB pathway genes related to cell proliferation, migration, and invasion. This novel finding reveals the diversity of circRNA functions in HCC and provides novel insights into the role of circRNAs.

CircRNA ITCH: Insight Into Its Role and Clinical Application Prospect in Tumor and Non-Tumor Diseases

CircRNA E3 ubiquitin protein ligase (ITCH) (circRNA ITCH, circ-ITCH), a stable closed-loop RNA derived from the 20q11.22 region of chromosome 20, is a new circRNA discovered in the cytoplasm in recent decades. Studies have shown that it does not encode proteins, but regulates proteins expression at different levels. It is down-regulated in tumor diseases and is involved in a number of biological activities, including inhibiting cell proliferation, migration, invasion, and promoting apoptosis. It can also alter disease progression in non-tumor disease by affecting the cell cycle, inflammatory response, and critical proteins. Circ-ITCH also holds a lot of promise in terms of tumor and non-tumor clinical diagnosis, prognosis, and targeted therapy. As a result, in order to aid clinical research in the hunt for a new strategy for diagnosing and treating human diseases, this study describes the mechanism of circ-ITCH as well as its clinical implications.

The roles of E3 ligases in Hepatocellular carcinoma

Hepatocarcinogenesis is a complex multistep biological process involving genetic and epigenetic alterations that are accompanied by activation of oncoproteins and inactivation of tumor suppressors, which in turn results in Hepatocellular carcinoma (HCC), one of the common tumors with high morbidity and mortality worldwide. The ubiquitin-proteasome system (UPS) is the key to protein degradation and regulation of physiological and pathological processes, and E3 ligases are key enzymes in the UPS that contain a variety of subfamily proteins involved in the regulation of some common signal pathways in HCC. There is growing evidence that many structural or functional dysfunctions of E3 are engaged in the development and progression of HCC. Herein, we review recent research advances in HCC-associated E3 ligases, describe their structure, classification, functional roles, and discuss some mechanisms of the abnormal activation or inactivation of the HCC-associated signal pathway due to the binding of E3 to known substrates. In addition, given the success of proteasome inhibitors in the treatment of malignant cancers, we characterize the current knowledge and future prospects for targeted therapies against aberrant E3 in HCC.

circITCH suppresses cell proliferation and metastasis through miR-660/TFCP2 pathway in melanoma

BACKGROUND

Melanoma is an aggressive disease that is rising in incidence. Advanced melanoma is still a life-threatening disease. CircRNAs are documented to be involved in melanoma progression. But circITCH role in melanoma remains unclear.

METHODS AND RESULTS

To explore the functions of circITCH in melanoma, levels of circITCH in melanoma tissues and paracarcinoma normal tissues were detected. To study the roles of circITCH in melanoma in terms of cell proliferation and migration, in vitro and in vivo experiments were performed. Mechanism study was designed to investigate the potential regulatory effect of circITCH in melanoma. Results revealed that circITCH expression was repressed in melanoma versus adjacent normal tissues. Function study showed that circITCH suppressed melanoma cell proliferation and metastasis. The mechanism study showed that circITCH-sponged miR-660 to upregulate TFCP2 and suppress melanoma progression.

CONCLUSIONS

The circITCH/miR-660/TFCP2 axis is involved in melanoma progression hence circITCH can be a diagnostic biomarker as well as a target for treating melanoma.

Circular RNA ITCH: An Emerging Multifunctional Regulator

In the last decade, numerous circRNAs were discovered by virtue of the RNA-Seq technique. With the deepening of experimental research, circRNAs have brought to light the key biological functions and progression of human diseases. CircRNA ITCH has been demonstrated to be a tumor suppressor in numerous cancers, and recently it was found to play an important role in bone diseases, diabetes mellitus, and cardiovascular diseases. However, the functions of circ-ITCH have not been completely understood. In this review, we comprehensively provide a conceptual framework to elucidate circ-ITCH biological functions of cell proliferation, apoptosis and differentiation, and the pathological mechanisms of inflammation, drug resistance/toxicity, and tumorigenesis. Finally, we summarize its clinical applications in various diseases. This research aimed at clarifying the role of circ-ITCH, which could be a promising therapeutic target.

ITCH E3 Ubiquitin Ligase downregulation compromises hepatic degradation of branched-chain amino acids

Objective

Metabolic syndrome, obesity, and steatosis are characterized by a range of dysregulations including defects in ubiquitin ligase tagging proteins for degradation. The identification of novel hepatic genes associated with fatty liver disease and metabolic dysregulation may be relevant to unravelling new mechanisms involved in liver disease progression

Methods

Through integrative analysis of liver transcriptomic and metabolomic obtained from obese subjects with steatosis, we identified itchy E ubiquitin protein ligase (ITCH) as a gene downregulated in human hepatic tissue in relation to steatosis grade. Wild-type or ITCH knockout mouse models of non-alcoholic fatty liver disease (NAFLD) and obesity-related hepatocellular carcinoma were analyzed to dissect the causal role of ITCH in steatosis

Results

We show that ITCH regulation of branched-chain amino acids (BCAAs) degradation enzymes is impaired in obese women with grade 3 compared with grade 0 steatosis, and that ITCH acts as a gatekeeper whose loss results in elevation of circulating BCAAs associated with hepatic steatosis. When ITCH expression was specifically restored in the liver of ITCH knockout mice, ACADSB mRNA and protein are restored, and BCAA levels are normalized both in liver and plasma

Conclusions

Our data support a novel functional role for ITCH in the hepatic regulation of BCAA metabolism and suggest that targeting ITCH in a liver-specific manner might help delay the progression of metabolic hepatic diseases and insulin resistance.

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ITCH expression is reduced in liver during NAFLD.

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Transcriptomics analysis of liver in obese women highlighted the interplay between ITCH and genes involved in BCAA degradation.

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Modulation of ITCH in models of metabolic hepatic diseases supported the association between ITCH and BCAA metabolism.

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Targeting ITCH in a liver specific manner might help to delay the progression of metabolic hepatic diseases and insulin resistance.

E2F1-induced microRNA-224-5p expression is associated with hepatocellular carcinoma cell migration, invasion and epithelial-mesenchymal transition via MREG

MicroRNA (miR)-224-5p has been reported to be associated with multiple types of cancer. However, its biological role and underlying mechanism in hepatocellular carcinoma (HCC) has yet to be fully elucidated. The aim of the present study was to investigate whether miR-224-5p mRNA expression level was increased in hepatocellular carcinoma and whether it was associated with poor prognosis. Decreased mRNA expression level of miR-224-5p was shown to suppress liver cancer cell migration, invasion and epithelial-mesenchymal transition (EMT). Mechanistically, E2F1 was found to regulate miR-224-5p expression by binding to its promoter region. Melanoregulin (MREG) was identified as the direct target of miR-224-5p by searching the TargetScan, miRDB and StarBase databases. Overexpression of MREG could attenuate liver cancer cell migration, invasion and EMT. Rescue experiments further confirmed that MREG was associated with the regulation of miR-224-5p in liver cancer. In addition, the E2F1/miR-224-5p axis was shown to promote liver cancer cell migration, invasion and EMT by regulating MREG expression. These results suggested that E2F1-induced upregulation of miR-224-5p may serve an important role in MREG-induced liver cancer cell migration, invasion and EMT, and highlights the regulatory function of miR-224-5p in liver cancer. Therefore, the E2F1/miR-224-5p/MREG axis may provide a theoretical basis for the clinical treatment of hepatocellular carcinoma.

Emerging roles of circular RNAs in liver cancer

Hepatocellular carcinoma and cholangiocarcinoma are the most common primary liver tumours, whose incidence and associated mortality have increased over recent decades. Liver cancer is often diagnosed late when curative treatments are no longer an option. Characterising new molecular determinants of liver carcinogenesis is crucial for the development of innovative treatments and clinically relevant biomarkers. Recently, circular RNAs (circRNAs) emerged as promising regulatory molecules involved in cancer onset and progression. Mechanistically, circRNAs are mainly known for their ability to sponge and regulate the activity of microRNAs and RNA-binding proteins, although other functions are emerging (e.g. transcriptional and post-transcriptional regulation, protein scaffolding). In liver cancer, circRNAs have been shown to regulate tumour cell proliferation, migration, invasion and cell death resistance. Their roles in regulating angiogenesis, genome instability, immune surveillance and metabolic switching are emerging. Importantly, circRNAs are detected in body fluids. Due to their circular structure, circRNAs are often more stable than mRNAs or miRNAs and could therefore serve as promising biomarkers - quantifiable with high specificity and sensitivity through minimally invasive methods. This review focuses on the role and the clinical relevance of circRNAs in liver cancer, including the development of innovative biomarkers and therapeutic strategies.

Circular RNA circFGFR1 Functions as an Oncogene in Glioblastoma Cells through Sponging to hsa-miR-224-5p

Recently, increased studies have shown the important regulatory role of circular RNA (circRNA) in cancer progression and development, including glioblastoma (GBM). However, the function of circRNAs in glioblastoma is still largely unclear. Here, we state that circFGFR1 is elevated in glioma cells, resulting in aggravated glioma aggravated malignancy. The upregulation of circFGFR1 also promotes glioma growth in mouse xenograft models. Furthermore, CXCR4 level in glioma cells is positively correlated with circFGFR1 level, and higher CXCR4 expression is found in circFGFR1 overexpression groups. The effect of circFGFR1 on glioma malignancy is abolished in CXCR4 knockout cells. Then, RIP, RNA pull-down, and luciferase reporter assay results showed that hsa-miR-224-5p directly binds to circFGFR1 and CXCR4 mRNA. The CXCR4 3′-untranslated region (UTR) activated luciferase activity was reduced with hsa-miR-224-5p transfection, while it is reversed when cotransfected with circFGFR1, indicating that circFGFR1 acts as a hsa-miR-244-5p sponge to increase CXCR4 expression. The hsa-miR-224-5p expression is negatively corrected with the glioma malignancy through inhibiting CXCR4 level. Besides, the circFGFR1-induced regulation in glioma malignancy is also abrogated in hsa-miR-224-5p knockout cells. Taken together, our findings suggest that circFGFR1 plays a critical role in the tumorigenic behaviors in glioma cells by upregulating CXCR4 expression via sponging to hsa-miR-224-5p. These findings provide a new perspective on circRNAs during GBM development.

LncRNA LINC01094 contributes to glioma progression by modulating miR-224-5p/CHSY1 axis

Glioma serves as the most common malignancy influencing modern people and is associated with severe morbidity and high mortality. Long non-coding RNAs (lncRNAs) as crucial regulators participate in multiple cancer progression. However, the role of lncRNA LINC01094 in the development of glioma remains unclear. Here, we aimed to explore the effect of lncRNA LINC01094 on the glioma progression and the underlying mechanism. Significantly, we revealed that the expression levels of LINC01094 were elevated in the glioma patient tissues compared to adjacent normal tissues. The LINC01094 expression was enhanced in the glioma cell lines. The depletion of LINC01094 inhibited cell viability and colony formation in the glioma cells. Meanwhile, the migration and invasion of glioma cells were impaired by the depletion of LINC01094. Mechanically, we identified that LINC01094 was able to sponge the miR-224-5p in the glioma cells and miR-224-5p inhibitor could reverse the effect of LINC01094 on glioma progression. In addition, miR-224-5p targeted CHSY1 and LINC01094 up-regulated CHSY1 by targeting miR-224-5p in the glioma cells. LINC01094 promoted glioma progression by the positive regulation of CHSY1. Moreover, tumorigenicity analysis showed that LINC01094 enhanced tumor growth of glioma in vivo. Thus, we conclude that lncRNA LINC01094 promotes glioma progression by modulating miR-224-5p/CHSY1 axis. Our finding provides new insights into the mechanism by which lncRNA LINC01094 contributes to the development of glioma, improving the understanding of lncRNA LINC01094 and glioma. LncRNA LINC01094, miR-224-5p, and CHSY1 may serve as potential targets for glioma.

Transcriptome Analysis of Rat Lungs Exposed to Moxa Smoke after Acute Toxicity Testing

The increasing use of moxibustion has led to a debate concerning the safety of this treatment in human patients. Inhalation of cigarette smoke induces lung inflammation and granulomas, the proliferation of alveolar epithelial cells, and other toxic effects; therefore, it is important to assess the influence of inhaled moxa smoke on the lungs. In the present study, a novel poisoning cabinet was designed and used to assess the acute toxicity of moxa smoke in rats. We evaluated pathological changes in rat lung tissue and analyzed differentially expressed genes (DEGs) using RNA-seq and transcriptomic analyses. Our results show that the maximum tolerable dose of moxa smoke was 290.036 g/m³ and LC50 was 537.65 g/m³. Compared with that of the control group, the degree of inflammatory cell infiltration in the lung tissues of group A rats (all dead group) was increased, while that in group E rats (all live group) remained unchanged. GO and KEGG enrichment analyses showed that the DEGs implicated in cell components, binding, and cancer were significantly enriched in the experimental groups compared with the profile of the control group. The expressions of MAFF, HSPA1B, HSPA1A, AOC1, and MX2 determined using quantitative real-time PCR were similar to those determined using RNA-seq, confirming the reliability of RNA-seq data. Overall, our results provide a basis for future evaluations of moxibustion safety and the development of moxibustion-based technology.

Lidocaine Inhibits Hepatocellular Carcinoma Development by Modulating circ_ITCH/miR-421/CPEB3 Axis

BACKGROUND

Lidocaine plays an anticancer role in hepatocellular carcinoma. Nevertheless, the mechanism of lidocaine in hepatocellular carcinoma remains largely unclear.

AIMS

This study aims to assess the function of lidocaine and explore the potential regulatory mechanism.

METHODS

Hepatocellular carcinoma cells were challenged via lidocaine. Cell proliferation, apoptosis, migration, and invasion were detected via colony formation, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, flow cytometry, Western blot, and transwell analyses. Circular RNA itchy E3 ubiquitin protein ligase (circ_ITCH), microRNA-421 (miR-421), and cytoplasmic polyadenylation element-binding protein 3 (CPEB3) abundances were detected via quantitative reverse transcription polymerase chain reaction or Western blot. The relationship between miR-421 and circ_ITCH or CPEB3 was tested via dual-luciferase reporter analysis. The role of circ_ITCH in lidocaine-challenged cell growth in vivo was assessed via xenograft model.

RESULTS

Lidocaine inhibited hepatocellular carcinoma cell proliferation by decreasing colony formation and cell viability. Lidocaine suppressed hepatocellular carcinoma cell migration and invasion and promoted apoptosis. circ_ITCH and CPEB3 levels were decreased in hepatocellular carcinoma tissues and cells, and were restored in cells via lidocaine treatment. circ_ITCH knockdown weakened the suppressive effect of lidocaine on hepatocellular carcinoma development, which was abolished via CPEB3 overexpression. circ_ITCH could modulate CPEB3 by competitively binding with miR-421. miR-421 knockdown mitigated the effect of circ_ITCH silence in lidocaine-challenged cells. circ_ITCH knockdown increased xenograft tumor growth.

CONCLUSIONS

Lidocaine represses hepatocellular carcinoma cell proliferation, migration, and invasion and promotes apoptosis via regulating circ_ITCH/miR-421/CPEB3 axis, indicating a new insight into the mechanism of lidocaine in hepatocellular carcinoma.

CircITCH: A Circular RNA With Eminent Roles in the Carcinogenesis

Circular RNAs (circRNAs) are a group of long non-coding RNAs with enclosed structure generated by back-splicing events. Numerous members of these transcripts have been shown to affect carcinogenesis. Circular RNA itchy E3 ubiquitin protein ligase (circITCH) is a circRNA created from back splicing events in ITCH gene, a protein coding gene on 20q11.22 region. ITCH has a role as a catalyzer for ubiquitination through both proteolytic and non-proteolytic routes. CircITCH is involved in the pathetiology of cancers through regulation of the linear isoform as well as serving as sponge for several microRNAs, namely miR-17, miR-224, miR-214, miR-93-5p, miR-22, miR-7, miR-106a, miR-10a, miR-145, miR-421, miR-224-5p, miR-197 and miR-199a-5p. CircITCH is also involved in the modulation of Wnt/β-catenin and PTEN/PI3K/AKT pathways. Except from a single study in osteosarcoma, circITCH has been found to exert tumor suppressor role in diverse cancers. In the present manuscript, we provided a comprehensive review of investigations that reported function of circITCH in the carcinogenesis.

Circ-SHPRH suppresses cadmium-induced transformation of human bronchial epithelial cells by regulating QKI expression via miR-224-5p

Circular RNAs (circRNAs) have been demonstrated to play critical roles in the pathogenesis of human cancers and carcinogenesis of several environmental pollutants. Nevertheless, the function of circRNAs in cadmium carcinogenesis is unclear. circ-SHPRH is down-regulated in many cancers including non-small cell lung cancer. In our present study, during cadmium-induced transformation of human bronchial epithelial BEAS-2B cells, epithelial-mesenchymal transition (EMT) was induced. Meanwhile, at the middle and late stages of cell transformation, cadmium down-regulated the expression of circ-SHPRH, as well as QKI, a tumor suppressor protein known to prevent the proliferation and EMT during progression of human cancers, compared with passage-matched control BEAS-2B cells. Overexpression of circ-SHPRH in cadmium-transformed BEAS-2B cells promoted the expression of QKI and significantly inhibited proliferation, EMT, invasion, migration and anchorage-independent growth in soft agar of the cells. Mechanistic studies showed that circ-SHPRH functioned as a sponge of miR-224-5p to regulate QKI expression. Interestingly, QKI and circ-SHPRH could form a positive-feedback loop that perpetuated circ-SHPRH/miR-224-5p/QKI axis. Collectively, our results demonstrated that circ-SHPRH inhibited cadmium-induced transformation of BEAS-2B cells through sponging miR-224-5p to regulate QKI expression under cadmium treatment. Our study uncovered a novel molecular mechanism involved in circRNAs in the development of lung cancer due to cadmium exposure.

Circular RNA ITCH Is a Tumor Suppressor in Clear Cell Renal Cell Carcinoma Metastasis through miR-106b-5p/PDCD4 Axis

High metastasis of clear cell renal cell carcinoma (ccRCC) significantly influenced survival rate of ccRCC patients. Here, we intended to investigate the impacts of circular RNA ITCH (circ-ITCH) on the metastasis of ccRCC. The expression of circ-ITCH in ccRCC tissues and cells was evaluated utilizing qRT-PCR. Transwell assay and wound healing were applied to investigate migration and invasion of ccRCC cells. Target gene prediction and screening and luciferase reporter gene assays were utilized to assess downstream target genes of circ-ITCH. Western blot was utilized to detect metastasis-related protein expression. A xenograft tumor model was established to evaluate the role of circ-ITCH in vivo. Results showed that circ-ITCH was low expressed in ccRCC tissues and cells. Downregulation circ-ITCH promoted cell migration, but overexpressing circ-ITCH inhibited cell migration and invasion in OSRC-2 and SW839 cells. Mechanism investigations claimed that circ-ITCH exerted its metastasis-inhibitory activity via sponging miR-106b-5p and regulating the expression of PDCD4. Conclusively, circ-ITCH suppresses ccRCC metastasis by enforcing PDCD4 expression through binding miR-106b-5p. circ-ITCH may function as a novel diagnostic target to suppress ccRCC metastasis.

The underlying molecular mechanism and identification of transcription factor markers for laryngeal squamous cell carcinoma

The screening and treatment of laryngeal squamous cell carcinoma (LSCC) still perplexes clinicians, making it necessary to explore new markers. To this end, this research examined the underlying molecular mechanism of LSCC based on high-throughput datasets (n = 249) from multiple databases. It also identified transcription factors (TFs) independently associated with LSCC prognosis. Through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses, differential expression genes of LSCC were deemed relevant to the extracellular matrix and its related structures or pathways, suggesting that the extracellular matrix plays an important role in LSCC. At the same time, several hub genes that may also have important roles in LSCC were identified via protein–protein interaction analysis, including CDC45, TPX2, AURKA, KIF2C, NUF, MUC1, MUC7, MUC4, MUC15, and MUC21. Eight unreported LSCC prognostic TFs – BCAT1, CHD4, FOXA2, GATA6, HNF1A, HOXB13, MAFF, and TCF4 – were screened via Kaplan–Meier curves. Cox analysis determined for the first time that HOXB13 expression and gender were independently associated with LSCC prognosis. Compared to control tissues, elevated expression of HOXB13 was found in LSCC tissues (standardized mean difference = 0.44, 95% confidence interval [0.13–0.76]). HOXB13 expression also makes it feasible to screen LSCC from non-LSCC (area under the curve = 0.77), and HOXB13 may play an essential role in LSCC by regulating HOXB7. In conclusion, HOXB13 may be a novel marker for LSCC clinical screening and treatment.

The androgen receptor expression and its activity have different relationships with prognosis in hepatocellular carcinoma

The role of the Androgen Receptor (AR) expression and its activity in the prognosis of hepatocellular carcinoma (HCC) remains inconclusive. The aim of this study is to analyze the role of the AR expression and its activity as prognostic biomarkers in HCC. Three-hundred and thirty-seven patients from The Cancer Genome Atlas (TCGA) (107 females; 59.42 years [SD = 13.0]) were included. To infer AR activity, the expression-profile of previously validated androgen responsive genes (ARGs) was included. AR activity was shown by the AR-Score-21 (21 ARGs) and AR-Score-13 (13 ARGs) that were computed based on the expression of the selected ARGs. Those ARGs whose expression was significantly different between histological grades were used for computing two new AR-Scores. HCC patients with higher AR expression showed a higher median overall survival (OS). AR-Score 21 and AR-Score-13 did not show any association with prognosis. Six of the 21 ARGs of the AR-Score-21 and 7 of the 13 ARGs of the AR-Score-13 showed a significant different expression profile among histological grades. Based on these differences, another two AR-Scores were computed (AR-Score-6 and AR-Score-7). They showed the relative increase of upregulated to downregulated ARGs in high-grade HCC. Higher AR activity inferred by these AR-Scores was associated with worse outcomes. The expression of AR is associated with a better prognosis in HCC. However, the activity of the AR seems to be qualitatively different among histological grades. The AR activity inferred by the shifted ARGs is associated with a worse prognosis in HCC patients.

CircAMOTL1 Promotes Tumorigenesis Through miR-526b/SIK2 Axis in Cervical Cancer

Background

Cervical cancer is one of the most common malignancies in women, leading to major health problems for its high morbidity and mortality. Numerous studies have demonstrated that circular RNAs (circRNAs) could be participated in the progression of multifarious diseases, especially plentiful carcinomas. CircAMOTL1 (angiomotin-like1, ID: hsa_circ_0004214), which is located on human chromosome 11:9 4532555-94533477, is involved in the occurrence of breast cancer, etc. However, the intrinsic and concrete molecular mechanism of circAMOTL1 in cervical carcinomas remained thoroughly unclear, which was also the bottleneck of circRNAs studies in cancer.

Methods

The relative expression levels of circAMOTL1 and miR-526b in cervical carcinoma patients’ specimens and cervical carcinoma cell lines were detected by RT-qPCR. Through experiments including loss-function and overexpression, the biological effects of circAMOTL1 and miR-526b on the proliferation, migration, apoptosis, and tumorigenicity were explored in cervical carcinomas. Dual luciferase reporter gene analysis, western blot, and other methods were adopted to explore the circAMOTL1 potential mechanism in cervical carcinomas.

Results

In our experiments, our researches displayed that circAMOTL1 was significantly higher expression in cervical carcinomas specimens and cell lines. Further experiments illustrated that the knockdown of circAMOTL1 could restrain the malignant phenotype, AKT signaling, and epithelial–mesenchymal transition (EMT) of in cervical carcinomas cells. Meanwhile miR-526b was downregulated in cervical carcinomas and even miR-526b could partially reverse circAMOTL1 function in malignant cervical tumor cells. CircAMOTL1 acts as a microRNA (miRNA) sponge that actively regulates the expression of salt-inducible kinase 2 (SIK2) to sponge miR-526b and subsequently increases malignant phenotypes of cervical carcinomas cells. In a word, circAMOTL1 acts a carcinogenic role and miR-526b serves as the opposite function of antioncogene in the cervical carcinoma pathogenesis.

Conclusion

CircAMOTL1-miR-526b-SIK2 axis referred to the malignant progression and development of cervical carcinomas. CircAMOTL1 expression was inversely correlated with miR-526b and positively correlated with SIK2 mRNA in cervical cancer tissues. Thus, circAMOTL1 exerted an oncogenic role in cervical cancer progression through sponging miR-526b. Taken together, our study revealed that circAMOTL1 acted as an oncogene and probably was a potential therapeutic target for the cervical cancer.