Neuronal CFL1 upregulation in head and neck squamous cell carcinoma enhances tumor-nerve crosstalk and promotes tumor growth.

Head and neck squamous cell carcinoma (HNSCC) is a prevalent cancer type, marked by a pronounced nerve density within the tumor microenvironment and a high rate of perineural invasion (PNI). Growing evidence suggests that the nervous system plays a vital role in HNSCC progression. Yet, the mechanisms governing cancer-nerve interactions remain largely elusive. Our research revealed that cofilin-1 (CFL1) is significantly overexpressed in HNSCC and correlates with both PNI and unfavorable prognosis. Utilizing multiplex fluorescent immunohistochemistry, we have localized CFL1 chiefly to the nerves adjacent to tumor sites. Significantly, it is the elevated expression of CFL1 in neuronal structures, rather than in the tumor cells, that aligns with diminished patient survival rates. We observed that HNSCC cells induced the expression of neuronal CFL1 and that the conditional knockout of neuronal CFL1 impedes tumor-nerve interactions. Both Gene Ontology functional enrichment analyses and Gene Set Enrichment Analysis demonstrate that CFL1 expression in HNSCC is associated with specific biological processes, including "RIBOSOME," "PROTEASOME," and "cadherin binding." In summary, HNSCC promotes the expression of CFL1 in nerves, which is essential for cancer-nerve interactions. The neuronal CFL1 is associated with PNI and may be a potential molecular prognostic marker of poor survival in HNSCC.

Distinct functional constraints driving conservation of the cofilin N-terminal regulatory tail.

Cofilin family proteins have essential roles in remodeling the cytoskeleton through filamentous actin depolymerization and severing. The short, unstructured N-terminal region of cofilin is critical for actin binding and harbors the major site of inhibitory phosphorylation. Atypically for a disordered sequence, the N-terminal region is highly conserved, but specific aspects driving this conservation are unclear. Here, we screen a library of 16,000 human cofilin N-terminal sequence variants for their capacity to support growth in S. cerevisiae in the presence or absence of the upstream regulator LIM kinase. Results from the screen and biochemical analysis of individual variants reveal distinct sequence requirements for actin binding and regulation by LIM kinase. LIM kinase recognition only partly explains sequence constraints on phosphoregulation, which are instead driven to a large extent by the capacity for phosphorylation to inactivate cofilin. We find loose sequence requirements for actin binding and phosphoinhibition, but collectively they restrict the N-terminus to sequences found in natural cofilins. Our results illustrate how a phosphorylation site can balance potentially competing sequence requirements for function and regulation.

Cellular heterogeneity and transcriptomic profiles during intrahepatic cholangiocarcinoma initiation and progression.

BACKGROUND AND AIMS: Intrahepatic cholangiocarcinoma (ICC) is not fully investigated, and how stromal cells contribute to ICC formation is poorly understood. We aimed to uncover ICC origin, cellular heterogeneity, and critical modulators during ICC initiation/progression, and to decipher how fibroblast and endothelial cells in the stromal compartment favor ICC progression. APPROACH AND RESULTS: We performed single-cell RNA sequencing (scRNA-seq) using AKT/Notch intracellular domain-induced mouse ICC tissues at early, middle, and late stages. We analyzed the transcriptomic landscape, cellular classification and evolution, and intercellular communication during ICC initiation/progression. We confirmed the findings using quantitative real-time PCR, western blotting, immunohistochemistry or immunofluorescence, and gene knockout/knockdown analysis. We identified stress-responding and proliferating subpopulations in late-stage mouse ICC tissues and validated them using human scRNA-seq data sets. By integrating weighted correlation network analysis and protein-protein interaction through least absolute shrinkage and selection operator regression, we identified zinc finger, MIZ-type containing 1 (Zmiz1) and Y box protein 1 (Ybx1) as core transcription factors required by stress-responding and proliferating ICC cells, respectively. Knockout of either one led to the blockade of ICC initiation/progression. Using two other ICC mouse models (YAP/AKT, KRAS/p19) and human ICC scRNA-seq data sets, we confirmed the orchestrating roles of Zmiz1 and Ybx1 in ICC occurrence and development. In addition, hes family bHLH transcription factor 1, cofilin 1, and inhibitor of DNA binding 1 were identified as driver genes for ICC. Moreover, periportal liver sinusoidal endothelial cells could differentiate into tip endothelial cells to promote ICC development, and this was Dll4-Notch4-Efnb2 signaling-dependent. CONCLUSIONS: Stress-responding and ICC proliferating subtypes were identified, and Zmiz1 and Ybx1 were revealed as core transcription factors in these subtypes. Fibroblast-endothelial cell interaction promotes ICC development.

Identification of the most damaging nsSNPs in the human CFL1 gene and their functional and structural impacts on cofilin-1 protein.

The cofilin-1 protein, encoded by CFL1, is an actin-binding protein that regulates F-actin depolymerization and nucleation activity through phosphorylation and dephosphorylation. CFL1 has been implicated in the development of neurodegenerative diseases (Alzheimer's disease and Huntington's disease), neuronal migration disorders (lissencephaly, epilepsy, and schizophrenia), and neural tube closure defects. Mutations in CFL1 have been associated with impaired neural crest cell migration and neural tube closure defects. In our study, various computational approaches were utilized to explore single-nucleotide polymorphisms (SNPs) in CFL1. The Variation Viewer and gnomAD databases were used to retrieve CFL1 SNPs, including 46 nonsynonymous SNPs (nsSNPs). The functional and structural annotation of SNPs was performed using 12 sequence-based web applications, which identified 20 nsSNPs as being the most likely to be deleterious or disease-causing. The conservation of cofilin-1 protein structures was illustrated using the ConSurf and PROSITE web servers, which projected the 12 most deleterious nsSNPs onto conserved domains, with the potential to disrupt the protein's functionality. These 12 nsSNPs were selected for protein structure construction, and the DynaMut/DUET servers predicted that the protein variants V7G, L84P, and L99A were the most likely to be damaging to the cofilin-1 protein structure or function. The evaluation of molecular docking studies demonstrated that the L99A and L84P cofilin-1 variants reduce the binding affinity for actin compared with the native cofilin-1 structure, and molecular dynamic simulation studies confirmed that these variants might destabilize the protein structure. The consequences of putative mutations on protein-protein interactions and post-translational modification sites in the cofilin-1 protein structure were analyzed. This study represents the first complete approach to understanding the effects of nsSNPs within the actin-depolymerizing factor/cofilin family, which suggested that SNPs resulting in L84P (rs199716082) and L99A (rs267603119) variants represent significant CFL1 mutations associated with disease development.

E2F4-induced AGAP2-AS1 up-regulation accelerates the progression of colorectal cancer via miR-182-5p/CFL1 axis.

BACKGROUND: Long non-coding RNAs (lncRNAs) are closely associated with the pathogenesis of numerous diseases including cancers. LncRNA AGAP2 Antisense RNA 1 (AGAP2-AS1) has been found to participate in the tumorigenesis of several kinds of human cancers. Nonetheless, its potential function in colorectal cancer (CRC) was still poorly investigated. METHODS: The expression level of RNAs or proteins was assessed by RT-qPCR or western blot analysis. Functional experiments were performed to analyze the role of AGAP2-AS1 in CRC in vitro and in vivo. Mechanism investigations were fulfilled to determine the potential mechanism of the molecules. RESULTS: AGAP2-AS1 expression was significantly elevated in CRC cells and could be transcriptionally activated by E2F Transcription Factor 4 (E2F4). Down-regulated AGAP2-AS1 could weaken CRC cell growth, migration, invasion, and epithelial-mesenchymal transition (EMT). MicroRNA-182-5p (miR-182-5p) was the target downstream molecule of AGAP2-AS1. Furthermore, Cofilin 1 (CFL1) was proved as the target of miR-182-5p. Mechanically, AGAP2-AS1 could boost the CFL1 expression via competitively binding to miR-182-5p in CRC. Importantly, CFL1 restoration could counteract the in vitro and in vivo suppression of depleted AGAP2-AS1 on CRC progression. CONCLUSION: E2F4-stimulated AGAP2-AS1 aggravated CRC development through regulating miR-182-5p/CFL1 axis, implying that AGAP2-AS1 might become a potent new target for future therapies for CRC.

Effects and mechanisms of FBXO31 on Taxol chemoresistance in esophageal squamous cell carcinoma.

Taxol is commonly used chemotherapy regimen for esophageal squamous cell carcinoma (ESCC). Study of the underlying mechanisms of Taxol chemoresistance provides better understanding of esophageal cancer treatment and may provide a rational molecular target for diagnosis and intervention. Here we showed FBXO31, which was reported to be highly expressed in ESCC and significantly associated with poor prognosis, could regulate ESCC chemosensitivity to Taxol. Silencing of FBXO31 in ESCC cells sensitized cells to Taxol treatment, evidenced by FACS analysis and TUNEL assay, showing as an increased apoptotic population in FBXO31-knockdown cells compared to the control cells. The mass spectrometry data and coimmunoprecipitation results showed FBXO31 could bind with cofilin-1. Cofilin-1 knockdown in FBXO31-overexpression cells reversed FBXO31-induced suppression of cell apoptosis, suggesting FBXO31-mediated Taxol chemoresistance is associated with cofilin-1. Furthermore, in vivo experiments confirmed that knockdown of FBXO31 sensitized ESCC to Taxol treatment. This finding substantiated a pivotal role of FBOX31 in ESCC chemoresistance, indicating that FBXO31 may be a potential indicator or target for drug resistance in ESCC.

Identification and functional characterization of Cofilin-1 as a new member of antimicrobial protein.

Cofilin-1 (Cfl1), a member of the ADF/cofilin family, has been identified as one of differentially expressed proteins in human dendritic cells challenged with lipopolysaccharide (LPS), suggesting that it may be involved in immune response. Here we showed that zebrafish cfl1 was markedly up-regulated by LPS and LTA treatment. We also showed that zebrafish recombinant Cfl1 (rCfl1) not only bound to the Gram-negative and positive bacteria A. hydrophila and S. aureus as well as their signature molecules LPS and LTA but also inhibited the growth of the bacteria. Moreover, we found that the heparin-binding motif-containing regions of Cfl1, i.e., Cfl19-25, Cfl134-51 and Cfl1108-125, like rCfl1, were also able to bind to LPS and LTA and to inhibit the bacterial growth. rCfl1, Cfl19-25, Cfl134-51, and Cfl1108-125 were all able to cause bacterial cell destruction, to induce membrane depolarization, and to stimulate intracellular ROS production. Finally, we showed that zebrafish Cfl1 could protect developing embryos/larvae against attack by the potential pathogen A. hydrophila. These data together indicate that zebrafish Cfl1 plays an immune-relevant role as a newly-characterized antimicrobial protein.

ABL1 and Cofilin1 promote T-cell acute lymphoblastic leukemia cell migration.

The fusion gene of ABL1 is closely related to tumor proliferation, invasion, and migration. It has been reported recently that ABL1 itself is required for T-cell acute lymphoblastic leukemia (T-ALL) cell migration induced by CXCL12. Further experiments revealed that ABL1 inhibitor Nilotinib inhibited leukemia cell migration induced by CXCL12, indicating the possible application of Nilotinib in T-ALL leukemia treatment. However, the interacting proteins of ABL1 and the specific mechanisms of their involvement in this process need further investigation. In the present study, ABL1 interacting proteins were characterized and their roles in the process of leukemia cell migration induced by CXCL12 were investigated. Co-immunoprecipitation in combination with mass spectrometry analysis identified 333 proteins that interact with ABL1, including Cofilin1. Gene ontology analysis revealed that many of them were enriched in the intracellular organelle or cytoplasm, including nucleic acid binding components, transfectors, or co-transfectors. Kyoto Encyclopedia of Genes and Genomes analysis showed that the top three enriched pathways were translation, glycan biosynthesis, and metabolism, together with human diseases. ABL1 and Cofilin1 were in the same complex. Cofilin1 binds the SH3 domain of ABL1 directly; however, ABL1 is not required for the phosphorylation of Cofilin1. Molecular docking analysis shows that ABL1 interacts with Cofilin1 mainly through hydrogen bonds and ionic interaction between amino acid residues. The mobility of leukemic cells was significantly decreased by Cofilin1 siRNA. These results demonstrate that Cofilin1 is a novel ABL1 binding partner. Furthermore, Cofilin1 participates in the migration of leukemia cells induced by CXCL12. These data indicate that ABL1 and Cofilin1 are possible targets for T-ALL treatment.

Serum levels of cytoskeleton remodeling proteins and their mRNA expression in tumor tissue of metastatic laryngeal and hypopharyngeal cancers.

Actin-binding proteins (ABPs) and various signaling systems are involved in the process of squamous cell carcinoma of the larynx and hypopharynx (SCCLH) metastasis. The clinical significance of these proteins has not yet been determined. We analyzed the relationship between the mRNA levels of cofilin 1 (CFL1), profilin 1 (PFN1), adenylyl cyclase-associated protein 1 (CAP1), SNAI1 and RND3 and SCCLH metastasis. The serum levels of the above ABPs were estimated and the relationship between them and their mRNA expressions was analyzed. The expression levels of ABP mRNAs were measured by real-time RT-PCR in paired tissue samples taken from 54 patients with SCCLH (T1-4N0-1M0). Expression analysis was performed using the 2-ΔΔCT method. The levels of ABPs in the blood serum were measured by ELISA. Statistical analysis was carried out using the SPSS Statistica 20.0 software package. No significant difference in the mRNA gene expression in tumor tissue of patients with T1-3N0M0 SCCLH and patients with T2-4N1-2M0 SCCLH was found. High expression of RND3 mRNA was accompanied by an increase in mRNA expression of all studied ABPs. In the blood serum of T2-4N1-2M0 patients, the level of PFN1 was lower by 21% and the level of CAP1 was higher by 75% than those observed in T1-4N0M0 patients. The data obtained showed that RND3 is involved in the regulation of molecular cascades of SCCLH metastasis. PFN1 and CAP1 serum levels can be good classifiers of metastases in patients with SCCLH.

The intrinsic amyloidogenic propensity of cofilin-1 is aggravated by Cys-80 oxidation: A possible link with neurodegenerative diseases.

Cofilin-1, an actin dynamizing protein, forms actin-cofilin rods, which is one of the major events that exacerbates the pathophysiology of amyloidogenic diseases. Cysteine oxidation in cofilin-1 under oxidative stress plays a crucial role in the formation of these rods. Others and we have reported that cofilin-1 possesses a self-oligomerization property in vitro and in vivo under physiological conditions. However, it remains elusive if cofilin-1 itself forms amyloid-like structures. We, therefore, hypothesized that cofilin-1 might form amyloid-like assemblies, with a potential to intensify the pathophysiology of amyloid-linked diseases. We used various in silico and in vitro techniques and examined the amyloid-forming propensity of cofilin-1. The study confirms that cofilin-1 possesses an intrinsic tendency of aggregation and forms amyloid-like structures in vitro. Further, we studied the effect of cysteine oxidation on the stability and structural features of cofilin-1. Our data show that oxidation at Cys-80 renders cofilin-1 unstable, leading to a partial loss of protein structure. The results substantiate our hypothesis and establish a strong possibility that cofilin-1 aggregation might play a role in cofilin-mediated pathology and the progression of several amyloid-linked diseases.

Hhex inhibits cell migration via regulating RHOA/CDC42-CFL1 axis in human lung cancer cells.

BACKGROUND: Hhex(human hematopoietically expressed homeobox), also known as PRH, is originally considered as a transcription factor to regulate gene expression due to its homebox domain. Increasing studies show that Hhex plays a significant role in development, including anterior-posterior axis formation, vascular development and HSCs self-renewal etc. Hhex is linked to many diseases such as cancers, leukemia, and type-2 diabetes. Although Hhex is reported to inhibit cell migration and invasion of breast and prostate epithelial cells by upregulating Endoglin expression, the effect and molecular mechanism for lung cancer cell motility regulation remains elusive. METHODS: Human non-small cell lung cancer cells and HEK293FT cells were used to investigate the molecular mechanism of Hhex regulating lung cancer cell migration by using Western blot, immunoprecipitation, wound-healing scratch assay, laser confocal. RESULTS: Our data indicated that Hhex could inhibit cell migration and cell protrusion formation in lung cancer cells. In addition, Hhex inhibited CFL1 phosphorylation to keep its F-actin-severing activity. RHOGDIA was involved in Hhex-induced CFL1 phosphorylation regulation. Hhex enhanced RHOGDIA interaction with RHOA/CDC42, thus maintaining RHOA/CDC42 at an inactive form. CONCLUSION: Collectively, these data indicate that Hhex inhibited the activation of RHOA/CDC42 by enhancing interaction of RHOGDIA with RHOA/CDC42, and then RHOA/ CDC42-p-CFL1 signaling pathway was blocked. Consequently, the formation of Filopodium and Lamellipodium on the cell surface was suppressed, and thus the ability of lung cancer cells to migrate was decreased accordingly. Our findings show Hhex plays an important role in regulating migration of lung cancer cells and may provide a potential target for lung cancer therapy. Video abstract.

ADF and cofilin-1 collaborate to promote cortical actin flow and the leader bleb-based migration of confined cells.

Melanoma cells have been shown to undergo fast amoeboid (leader bleb-based) migration, requiring a single large bleb for migration. In leader blebs, is a rapid flow of cortical actin that drives the cell forward. Using RNAi, we find that co-depleting cofilin-1 and actin depolymerizing factor (ADF) led to a large increase in cortical actin, suggesting that both proteins regulate cortical actin. Furthermore, severing factors can promote contractility through the regulation of actin architecture. However, RNAi of cofilin-1 but not ADF led to a significant decrease in cell stiffness. We found cofilin-1 to be enriched at leader bleb necks, whereas RNAi of cofilin-1 and ADF reduced bleb sizes and the frequency of motile cells. Strikingly, cells without cofilin-1 and ADF had blebs with abnormally long necks. Many of these blebs failed to retract and displayed slow actin turnover. Collectively, our data identifies cofilin-1 and ADF as actin remodeling factors required for fast amoeboid migration.

Relationship of intracellular proteolysis with CAP1 and cofilin1 in non-small-cell lung cancer.

The main cause of death in non-small-cell lung cancer (NSCLC) is tumor progression, in which metastasis and invasion play an important role. The metastatic cascade is marked by a change in morphological, biological, biochemical and functional characteristics, including the acquisition of cellular mobility. The migration activity of tumor cells determines the work of actin-binding proteins that cause their functional partners CAP1 and cofilin. Of interest is the study of the regulation of working tandem CAP1/cofilin in NSCLC. The mechanism that regulates the level of proteins in cells is proteolysis, carried out by proteasomes and calpains. Therefore, the aim of this study was to estimate the expression of CAP1/CFL1 mRNA and their protein level in NSCLC tissues, and to analyze the possible mechanisms of their regulation by the proteasome and calpain systems. Samples of NSCLC and histological unchanged lung tissue were used (n = 42). The CAP1 and CFL1 mRNA expressions were determined by real-time PCR, the contents of proteins encoded by them were determined by Western blotting, and the activity of proteasomes and calpains by the fluorimetric method. There was an increase in the expression of mRNA and protein levels of CAP1 and cofilin in the tumor tissue compared with the unchanged lung tissue. The expression of mRNA and the level of CAP1 in tumor tissue increased during growth of the primary tumor. The cofilin level in the tumor tissue decreases against the background of increased expression of its mRNA. At the same time, during tumor growth, the activity of proteasomes and calpains increased. A negative regression relationships between the activity of proteasomes and the levels of CAP1 and cofilin, as well as the activity of calpains and the level of cofilin, were found. It can be assumed that proteasomes and calpains are involved in the degradation of CAP1 and cofilin. The data obtained suggest the importance of CAP1, cofilin and proteolytic systems in the tumor transformation and lymphogenous metastasis.

MiR-509-3p Induces Apoptosis and Affects the Chemosensitivity of Cervical Cancer Cells by Targeting the RAC1/PAK1/LIMK1/Cofilin Pathway.

Chemoresistance is one of the main factors of treatment failure of cervical cancer (CC). Here, we intended to discover the role and mechanism of miR-509-5p in the paclitaxel chemoresistance of CC cells. RT-PCR was conducted to verify miR-509-3p expression. HCC94 and C-33A paclitaxel-resistant CC cell models were constructed. Additionally, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry were performed to verify the viability and apoptosis of HCC94 and C-33A cells after upregulating miR-509-3p. Besides, the downstream target of miR-509-3p was analyzed by bioinformatics, and the targeted relationship between miR-509-3p and RAC1 was identified by the dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Further, the expression of apoptotic proteins (Bcl2, Bax, and Caspase3) and the RAC1/PAK1/LIMK1/Cofilin pathway was monitored by Western blot. The result showed that upregulating miR-509-3p markedly inhibited the viability and promoted the apoptosis of CC cells. On the other hand, miR-509-3p was distinctly downregulated in paclitaxel-resistant HCC94 and C-33A cells (vs. normal cells). The transfection of miR-509-3p mimics notably increased their sensitivity to paclitaxel. Meanwhile, RAC1 was found as the potential target of miR-509-3p in bioinformatics analysis. Moreover, the RAC1/p21 (RAC1) activated kinase 1 (PAK1)/LIM kinase 1 (LIMK1)/Cofilin pathway was significantly activated in paclitaxel-resistant HCC94 and C-33A cells, while miR-509-3p overexpression significantly inactivated this pathway. Additionally, downregulation of RAC1 also partly reversed the paclitaxel-resistance of CC cells and inhibited PAK1/LIMK1/Cofilin. All in all, miR-509-3p enhances the apoptosis and chemosensitivity of CC cells by regulating the RAC1/PAK1/LIMK1/Cofilin pathway.

Hsa-miR-107 regulates chemosensitivity and inhibits tumor growth in hepatocellular carcinoma cells.

Hepatocellular carcinoma is a common type of liver cancer. Resistance to chemotherapeutic agents is a major problem in cancer therapy. MicroRNAs have been reported in cancer development and tumor growth; however, the relationship between chemoresistance and hepatocellular carcinoma needs to be fully investigated. Here, we treated hepatocellular carcinoma cell line (HA22T) with a histone deacetylase inhibitor to establish hepatocellular carcinoma-resistant cells (HDACi-R) and investigated the molecular mechanisms of chemoresistance in HCC cells. Although histone deacetylase inhibitor could not enhance cell death in HDACi-R but upregulation of miR-107 decreased cell viability both in parental cells and resistance cells, decreased the expression of cofilin-1, enhanced ROS-induced cell apoptosis, and dose-dependently sensitized HDACi-R to HDACi. Further, miR-107 upregulation resulted in tumor cell disorganization in both HA22T and HDACi-R in a mice xenograft model. Our findings demonstrated that miR-107 downregulation leads to hepatocellular carcinoma cell resistance in HDACi via a cofilin-1-dependent molecular mechanism and ROS accumulation.

Hypoxia-induced cofilin 1 promotes hepatocellular carcinoma progression by regulating the PLD1/AKT pathway.

BACKGROUND: Hepatocellular carcinoma (HCC) is the fourth fatal malignant tumour type worldwide. However, the exact molecular mechanism involved in HCC progression remains unclear. METHODS: Three pairs of HCC and matched portal vein tumour thrombus (PVTT) tissue samples were analysed by isobaric tags for relative and absolute quantification (iTRAQ) assay to investigate the differentially expressed proteins. Real-time quantitative PCR, immunostaining, and immunoblotting were performed to detect cofilin 1 (CFL1) in HCC and non-tumour tissues. CCK8 and EdU, and Transwell assays, respectively, determined cell proliferation, migration, and invasion of HCC cells. Further, subcutaneous and tail vein injection were performed in nude mice for investigating HCC growth and lung metastasis in vivo. Regulatory effect of hypoxia-inducible factor-1α (HIF-1α) on CFL1 was confirmed by chromatin immunoprecipitation (ChIP) assay. Finally, interaction between CFL1 and phospholipase D1 (PLD1) was studied using immunoprecipitation (IP) assay. RESULTS: The iTRAQ analysis identified expression of CFL1 to be significantly upregulated in PVTT than in HCC tissues. Increased expression of CFL1 was closely associated with unfavourable clinical features, and was an independent risk predictor of overall survival in HCC patients. The knockdown of CFL1 inhibited cell growth viability, invasiveness, and epithelial-mesenchymal transformation (EMT) in HCC cells. Furthermore, CFL1 silencing significantly suppressed the growth and lung metastasis of HCC cells in nude mice. Next, HIF-1α directly regulated CFL1 transcription by binding to the hypoxia-responsive element (HRE) in the promoter. Moreover, we disclosed the interaction between CFL1 and PLD1 in HCC cells using IP assay. Mechanistically, CFL1 maintained PLD1 expression by repressing ubiquitin-mediated protein degradation, thereby activating AKT signalling in HCC cells. Notably, the CFL1/PLD1 axis was found mediating the hypoxia-induced activation of the AKT pathway and EMT. CONCLUSION: The analysis suggests that hypoxia-induced CFL1 increases the proliferation, migration, invasion, and EMT in HCC by activating the PLD1/AKT pathway.

A 9 mRNAs-based diagnostic signature for rheumatoid arthritis by integrating bioinformatic analysis and machine-learning.

BACKGROUND: Rheumatoid arthritis (RA) is an autoimmune rheumatic disease that carries a substantial burden for both patients and society. Early diagnosis of RA is essential to prevent disease progression and select an optimal therapeutic strategy. However, RA diagnosis is challenging, partly due to a lack of reliable biomarkers. Here, we aimed to explore the diagnostic signature and establish a predictive model of RA. METHODS: The mRNA expression profiling data of GSE17755, containing blood samples of 112 RA patients and 53 healthy control patients, were obtained from the Gene Expression Omnibus (GEO) database, followed by differential expression, GO (Gene Ontology), and KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis. A PPI network was constructed to select candidate hub genes, then logistic regression and random forest models were established based on the identified genes. RESULTS: Significantly, we identified 52 differentially expressed genes (DEGs), including 16 upregulated genes and 36 downregulated genes in RA samples compared with control samples. GO and KEGG analysis showed that several immune-related cellular processes were particularly enriched. We identified nine hub genes in the PPI network, including CFL1, COTL1, ACTG1, PFN1, LCP1, LCK, HLA-E, FYN, and HLA-DRA. The logistic regression and random forest models based on the nine identified genes reliably distinguished the RA samples from the healthy samples with substantially high AUC. CONCLUSION: The diagnostic logistic regression and random forest models based on nine hub genes reliably predicted the occurrence of RA. Our findings could provide new insights into RA diagnostics.

Actin filament oxidation by MICAL1 suppresses protections from cofilin-induced disassembly.

Proteins of the ADF/cofilin family play a central role in the disassembly of actin filaments, and their activity must be tightly regulated in cells. Recently, the oxidation of actin filaments by the enzyme MICAL1 was found to amplify the severing action of cofilin through unclear mechanisms. Using single filament experiments in vitro, we found that actin filament oxidation by MICAL1 increases, by several orders of magnitude, both cofilin binding and severing rates, explaining the dramatic synergy between oxidation and cofilin for filament disassembly. Remarkably, we found that actin oxidation bypasses the need for cofilin activation by dephosphorylation. Indeed, non-activated, phosphomimetic S3D-cofilin binds and severs oxidized actin filaments rapidly, in conditions where non-oxidized filaments are unaffected. Finally, tropomyosin Tpm1.8 loses its ability to protect filaments from cofilin severing activity when actin is oxidized by MICAL1. Together, our results show that MICAL1-induced oxidation of actin filaments suppresses their physiological protection from the action of cofilin. We propose that, in cells, direct post-translational modification of actin filaments by oxidation is a way to trigger their disassembly.

TGF-ß1 induces amoeboid-to-mesenchymal transition of CD44high oral squamous cell carcinoma cells via miR-422a downregulation through ERK activation and Cofilin-1 phosphorylation.

BACKGROUND: The objective of this study was to clarify the molecular mechanism of amoeboid-to-mesenchymal transition (AMT) of CD44high oral squamous cell carcinoma (OSCC) cells. METHODS: Morphology and expression of mesenchymal genes were investigated in CD44high OSCC cells (CD44high OM-1 cells) cultured on laminin-coated soft silicone gel. Additionally, microarray analysis was performed to investigate microRNA (miRNA) expression inhibited by transforming growth factor-ß1 (TGF-ß1) in CD44high OM-1 cells. RESULTS: When CD44high OM-1 cells were cultured on 2.0-kPa laminin-coated silicone gel, the cells exhibited an amoeboid-like round morphology. Cofilin-1 expression was found in the nucleus and cytoplasm of amoeboid-like CD44high OM-1 cells. The invasive capacity was significantly reduced after Cofilin-1 knockdown. Additionally, Cofilin-1 knockdown cells had an irregularly extended shape. Phosphorylated Cofilin-1 was significantly upregulated by TGF-ß1. Additionally, TGF-ß1 enhanced N-cadherin and Snail mRNA expression and induced a spindle-shaped morphology. ERK1/2 phosphorylation was induced by TGF-ß1. Microarray analysis revealed that miR-422a exhibited the greatest downregulation (fold change: 0.22) in the presence of TGF-ß1. Importantly, TGF-ß1-inhibited miR-422a expression was recovered by the ERK inhibitor or ERK1/2 knockdown. Additionally, miR-422a inhibitor-transfected CD44high OM-1 cells exhibited high N-cadherin and Snail mRNA expression. Furthermore, Cofilin-1 knockdown and miR-422a inhibition induced a spindle cell morphology. CONCLUSION: Cofilin-1 is involved in the invasive ability of CD44high OSCC cells. TGF-ß1 contributes to AMT by downregulation of miR-422a via ERK activation and Cofilin-1 phosphorylation. Our findings suggest that miR-422a and Cofilin-1 play major roles in the maintenance of amoeboid-like CD44high cells.

Association of mRNA Expression Levels of LRP1 and Actin-Binding Proteins with the Development of Laryngeal and Laryngopharyngeal Squamous Cell Carcinoma.

We analyzed the association of the level of mRNA expression of the main endocytosis receptor LRP1 and actin-binding proteins (ezrin, profilin-1, cofilin-1, and adenylyl cyclase-associated protein 1) with the development and metastasis of laryngeal and laryngopharyngeal squamous cell carcinoma. The mRNA expression was evaluated in paired tissue samples using quantitative reverse transcription real-time PCR (RT-qPCR) and SYBR Green reagents. The study included 38 patients with stage T1-4N0-1M0 laryngeal and laryngopharyngeal squamous cell carcinoma and 10 patients with chronic hyperplastic laryngitis or grade II-III epithelial dysplasia. The expression of LRP1 in patients with laryngeal and laryngopharyngeal squamous cell carcinoma depended on the stage of the tumor process. Against the background of low expression of LRP1 mRNA, the relationship between cofilin 1 and profilin 1 expression became stronger (r=0.08; p=0.05) and a correlation between cofilin 1 and esrin expression (r=0.7; p=0.05) appeared. Studies on a larger patient cohort are required to make a definite conclusion on the role of LRP1 in the development of laryngeal and laryngopharyngeal squamous cell carcinoma.