Cofilin drives cell-invasive and metastatic responses to TGF-β in prostate cancer

Prostate Cancer: De-regulated Circular RNAs With Efficacy in Preclinical In Vivo Models

Therapy resistance, including castration-resistance and metastasis, remains a major hurdle in the treatment of prostate cancer. In order to identify novel therapeutic targets and treatment modalities for prostate cancer, we conducted a comprehensive literature search on PubMed to identify de-regulated circular RNAs that influence treatment efficacy in preclinical prostate cancer-related in vivo models. Our analysis identified 49 circular RNAs associated with various processes, including treatment resistance, transmembrane and secreted proteins, transcription factors, signaling cascades, human antigen R, nuclear receptor binding, ubiquitination, metabolism, epigenetics and other target categories. The identified targets and circular RNAs can be further scrutinized through target validation approaches. Down-regulated circular RNAs are candidates for reconstitution therapy, while up-regulated RNAs can be inhibited using small interfering RNA (siRNA), antisense oligonucleotides (ASO) or clustered regularly interspaced short palindromic repeats/CRISPR associated (CRISPR-CAS)-related approaches.

Unleashing the power of peptides in prostate cancer immunotherapy: mechanism, facts and perspectives

Prostate cancer, the second most common cancer in men, often progresses to castration-resistant prostate cancer despite androgen deprivation therapy. Immunotherapy, revolutionary in cancer treatment, has limited efficacy in prostate cancer due to its "cold tumor" nature. Peptides, with unique advantages, offer new hope. This review explores how peptide-based tumor immunotherapy can transform prostate cancer from a "cold" to a "hot" state. It modulates the immunosuppressive tumor microenvironment by regulating non-immune cells (such as cancer-associated fibroblasts, endothelial cells, and adipose stromal cells), repolarizing tumor-associated macrophages, activating NK cells, and tuning cytokines. Additionally, peptides can induce immunogenic cell death (ICD) in prostate cancer cells through ferroptosis, pyroptosis, and autophagy modulation. The review also revisits existing prostate cancer immunotherapies, including immune checkpoint blockade, CAR T cell therapy, and dendritic cell vaccines, highlighting how peptides can enhance their effectiveness and safety. Finally, two peptide-based immunotherapy strategies in the development stage, peptide-integrated Proteolysis-Targeting Chimera therapy and peptide-involved epigenomic therapy, are introduced, showing great potential for future prostate cancer treatment.

Protein-Based Predictive Biomarkers to Personalize Neoadjuvant Therapy for Bladder Cancer-A Systematic Review of the Current Status

The clinical outcome of patients with muscle-invasive bladder cancer (MIBC) is poor despite the approval of neoadjuvant chemotherapy or immunotherapy to improve overall survival after cystectomy. MIBC subtypes, immune, transcriptome, metabolomic signatures, and mutation burden have the potential to predict treatment response but none have been incorporated into clinical practice, as tumor heterogeneity and lineage plasticity influence their efficacy. Using the PRISMA statement, we conducted a systematic review of the literature, involving 135 studies published within the last five years, to identify studies reporting on the prognostic value of protein-based biomarkers for response to neoadjuvant therapy in patients with MIBC. The studies were grouped based on biomarkers related to molecular subtypes, cancer stem cell, actin-cytoskeleton, epithelial-mesenchymal transition, apoptosis, and tumor-infiltrating immune cells. These studies show the potential of protein-based biomarkers, especially in the spatial context, to reduce the influence of tumor heterogeneity on a biomarker's prognostic capability. Nevertheless, currently, there is little consensus on the methodology, reagents, and the scoring systems to allow reliable assessment of the biomarkers of interest. Furthermore, the small sample size of several studies necessitates the validation of potential prognostic biomarkers in larger multicenter cohorts before their use for individualizing neoadjuvant therapy regimens for patients with MIBC.

Role of actin-binding proteins in prostate cancer

The molecular mechanisms driving the onset and metastasis of prostate cancer remain poorly understood. Actin, under the control of actin-binding proteins (ABPs), plays a crucial role in shaping the cellular cytoskeleton, which in turn supports the morphological alterations in normal cells, as well as the invasive spread of tumor cells. Previous research indicates that ABPs of various types serve distinct functions, and any disruptions in their activities could predispose individuals to prostate cancer. These ABPs are intricately implicated in the initiation and advancement of prostate cancer through a complex array of intracellular processes, such as severing, linking, nucleating, inducing branching, assembling, facilitating actin filament elongation, terminating elongation, and promoting actin molecule aggregation. As such, this review synthesizes existing literature on several ABPs linked to prostate cancer, including cofilin, filamin A, and fascin, with the aim of shedding light on the molecular mechanisms through which ABPs influence prostate cancer development and identifying potential therapeutic targets. Ultimately, this comprehensive examination seeks to contribute to the understanding and management of prostate diseases.

Decoding the tumour-modulatory roles of LIMK2

LIM domains kinase 2 (LIMK2) is a 72 kDa protein that regulates actin and cytoskeleton reorganization. Once phosphorylated by its upstream activator (ROCK1), LIMK2 can phosphorylate cofilin to inactivate it. This relieves the levering stress on actin and allows polymerization to occur. Actin rearrangement is essential in regulating cell cycle progression, apoptosis, and migration. Dysregulation of the ROCK1/LIMK2/cofilin pathway has been reported to link to the development of various solid cancers such as breast, lung, and prostate cancer and liquid cancer like leukemia. This review aims to assess the findings from multiple reported in vitro, in vivo, and clinical studies on the potential tumour-regulatory role of LIMK2 in different human cancers. The findings of the selected literature unraveled that activated AKT, EGF, and TGF-β pathways can upregulate the activities of the ROCK1/LIMK2/cofilin pathway. Besides cofilin, LIMK2 can modulate the cellular levels of other proteins, such as TPPP1, to promote microtubule polymerization. The tumour suppressor protein p53 can transactivate LIMK2b, a splice variant of LIMK2, to induce cell cycle arrest and allow DNA repair to occur before the cell enters the next phase of the cell cycle. Additionally, several non-coding RNAs, such as miR-135a and miR-939-5p, could also epigenetically regulate the expression of LIMK2. Since the expression of LIMK2 is dysregulated in several human cancers, measuring the tissue expression of LIMK2 could potentially help diagnose cancer and predict patient prognosis. As LIMK2 could play tumour-promoting and tumour-inhibiting roles in cancer development, more investigation should be conducted to carefully evaluate whether introducing a LIMK2 inhibitor in cancer patients could slow cancer progression without posing clinical harms.

CFL1 is Implicated in Chronic Myeloid Leukemia Response during Imatinib Therapy

Cofilin (CFL1) is one critical member of the actin deploy family (ADF). Overexpression of CFL1 is associated with aggressive features and poor prognosis in malignancies. We evaluated the expression of CFL1 in patients with chronic myeloid leukemia in the chronic phase (CML-CP), acute myelocytic leukemia (AML) and healthy controls. The role of CFL1 in imatinib therapy was also investigated using cell line. We found that the expression of CFL1 was lower in CML patients than that in healthy controls, and was significantly upregulated after imatinib therapy (p<0.05). CML patients with lower CFL1 achieved higher Major molecular response (MMR) rate after 6 months of imatinib therapy (p<0.05). Cofilin, P-cofilin and F-actin, especially branched F-actin were all upregulated after imatinib therapy. The lower CFL1 expression before treatment may predicts a better response to imatinib. Imatinib affects F-actin remodeling in CML patients by regulating CFL1 expression and activity.

AKAP2-anchored protein phosphatase 1 controls prostatic neuroendocrine carcinoma cell migration and invasion

Prostate cancer (PC) is the second leading cause of cancer-related death in men. The growth of primary prostate cancer cells relies on circulating androgens and thus the standard therapy for the treatment of localized and advanced PC is the androgen deprivation therapy. Prostatic neuroendocrine carcinoma (PNEC) is an aggressive and highly metastatic subtype of prostate cancer, which displays poor prognosis and high lethality. Most of PNECs develop from prostate adenocarcinoma in response to androgen deprivation therapy, however the mechanisms involved in this transition and in the elevated biological aggressiveness of PNECs are poorly defined. Our current findings indicate that AKAP2 expression is dramatically upregulated in PNECs as compared to non-cancerous prostate tissues. Using a PNEC cell model, we could show that AKAP2 is localized both intracellularly and at the cell periphery where it colocalizes with F-actin. AKAP2 and F-actin interact directly through a newly identified actin-binding domain located on AKAP2. RNAi-mediated silencing of AKAP2 promotes the phosphorylation and deactivation of cofilin, a protein involved in actin turnover. This effect correlates with a significant reduction in cell migration and invasion. Co-immunoprecipitation experiments and proximity ligation assays revealed that AKAP2 forms a complex with the catalytic subunit of protein phosphatase 1 (PP1) in PNECs. Importantly, AKAP2-mediated anchoring of PP1 to the actin cytoskeleton regulates cofilin dephosphorylation and activation, which, in turn, enhances F-actin dynamics and favors migration and invasion. In conclusion, this study identified AKAP2 as an anchoring protein overexpressed in PNECs that controls cancer cell invasive properties by regulating cofilin phosphorylation.

The tumor-enriched small molecule gambogic amide suppresses glioma by targeting WDR1-dependent cytoskeleton remodeling

Glioma is the most prevalent brain tumor, presenting with limited treatment options, while patients with malignant glioma and glioblastoma (GBM) have poor prognoses. The physical obstacle to drug delivery imposed by the blood‒brain barrier (BBB) and glioma stem cells (GSCs), which are widely recognized as crucial elements contributing to the unsatisfactory clinical outcomes. In this study, we found a small molecule, gambogic amide (GA-amide), exhibited the ability to effectively penetrate the blood-brain barrier (BBB) and displayed a notable enrichment within the tumor region. Moreover, GA-amide exhibited significant efficacy in inhibiting tumor growth across various in vivo glioma models, encompassing transgenic and primary patient-derived xenograft (PDX) models. We further performed a genome-wide clustered regularly interspaced short palindromic repeats (CRISPR) knockout screen to determine the druggable target of GA-amide. By the combination of the cellular thermal shift assay (CETSA), the drug affinity responsive target stability (DARTS) approach, molecular docking simulation and surface plasmon resonance (SPR) analysis, WD repeat domain 1 (WDR1) was identified as the direct binding target of GA-amide. Through direct interaction with WDR1, GA-amide promoted the formation of a complex involving WDR1, MYH9 and Cofilin, which accelerate the depolymerization of F-actin to inhibit the invasion of patient-derived glioma cells (PDCs) and induce PDC apoptosis via the mitochondrial apoptotic pathway. In conclusion, our study not only identified GA-amide as an effective and safe agent for treating glioma but also shed light on the underlying mechanisms of GA-amide from the perspective of cytoskeletal homeostasis.

Glioma and post-translational modifications: A complex relationship

Post-translational modifications (PTMs) are common covalent processes in biochemical pathways that alter protein function and activity. These modifications occur through proteolytic cleavage or attachment of modifying groups, such as phosphoryl, methyl, glycosyl, or acetyl groups, with one or more amino acid residues of a single protein. Some PTMs also present crosstalk abilities that affect both protein functionality and structure, creating new proteoforms. Any alteration in organism homeostasis may be a cancer hallmark. Cataloging PTMs and consequently, emerging proteoforms, present new therapeutic targets, approaches, and opportunities to discover additional discriminatory biomarkers in disease diagnostics. In this review, we focus on experimentally confirmed PTMs and their potential crosstalk in glioma research to introduce new opportunities for this tumor type, which emerge within the PTMomics area.

HIF1A-repressed PUS10 regulates NUDC/Cofilin1 dependent renal cell carcinoma migration by promoting the maturation of miR-194-5p

BACKGROUND

Renal cell carcinoma (RCC) is characterized by a high rate of distant metastasis, which leads to poor prognosis in patients with advanced RCC. PUS10 has been recognized as a member of the pseudouridine synthase family, and recently other functions beyond the synthesis of the RNA modification have been uncovered. However, little is known about its role in diseases such as cancer.

METHODS

RT-qPCR, western blot and immunohistochemistry were used to measure the expression of PUS10 in RCC tissues. Transwell assay, wound healing assay, and in vivo metastasis model were conducted to determine the function of PUS10 in RCC progression. MicroRNA sequencing and GEO database were used to screen for the downstream microRNAs of PUS10. RNA immunoprecipitation, dual luciferase reporter assay, immunostaining, and rescue experiments were employed to establish the PUS10/miR-194-5p/nuclear distribution protein C(NUDC)/Cofilin1 axis in RCC migration. Chromatin immunoprecipitation and dual luciferase reporter assay were used to verify its upstream transcriptional regulator.

RESULTS

The expression of PUS10 was significantly decreased in RCC tissues, and low expression predicted poor prognosis. In vitro and in vivo experiments showed that PUS10 suppressed RCC migration, which, however, was independent of its classical pseudouridine catalytic function. Mechanically, PUS10 promoted the maturation of miR-194-5p, which sequentially inhibited RCC migration via disrupting NUDC-dependent cytoskeleton. Furthermore, hypoxia and HIF-1 A were found involved in the downregulation of PUS10.

CONCLUSION

We unraveled PUS10 restrained RCC migration via the PUS10/miR-194-5p/NUDC/Cofilin1 pathway, which independent of its classical catalytic function. Furthermore, a linkage between the critical tumor microenvironment hallmark with malfunction of the forementioned metastasis inhibition mechanism was presented, as demonstrated by repressed expression of PUS10 due to hypoxia and HIF-1A.

LIMK2 promotes melanoma tumor growth and metastasis through G3BP1-ESM1 pathway-mediated apoptosis inhibition

Melanoma is the leading cause of skin cancer-related deaths, and current melanoma therapies, including targeted therapies and immunotherapies, benefit only a subset of metastatic melanoma patients due to either intrinsic or acquired resistance. LIM domain kinase 2 (LIMK2) is a serine/threonine kinase that plays an important role in the regulation of actin filament dynamics. Here, we show that LIMK2 is overexpressed in melanoma, and its genetic or pharmacological inhibition impairs melanoma tumor growth and metastasis in both cell culture and mice. To determine the mechanism by which LIMK2 promotes melanoma tumor growth and metastatic progression, we performed a phosphoproteomics analysis and identified G3BP1 as a key LIMK2 target, which mirrored the effects of LIMK2 inhibition when inhibited. To further determine the role of G3BP1 downstream of LIMK2, we knocked down the expression of G3BP1, performed RNA-seq analysis, and identified ESM1 as a downstream target of G3BP1. G3BP1 was required for ESM1 mRNA stability, and ESM1 ectopic expression rescued LIMK2 or G3BP1 inhibition-induced suppression of melanoma growth and metastatic attributes. These results collectively identify the LIMK2→G3BP1→ESM1 pathway as a facilitator of melanoma tumor growth and metastasis and document that LIMK2 is a therapeutically tractable target for melanoma therapy.

Anoikis in phenotypic reprogramming of the prostate tumor microenvironment

Prostate cancer is one of the most common malignancies in males wherein 1 in 8 men are diagnosed with this disease in their lifetime. The urgency to find novel therapeutic interventions is associated with high treatment resistance and mortality rates associated with castration-resistant prostate cancer. Anoikis is an apoptotic phenomenon for normal epithelial or endothelial cells that have lost their attachment to the extracellular matrix (ECM). Tumor cells that lose their connection to the ECM can die via apoptosis or survive via anoikis resistance and thus escaping to distant organs for metastatic progression. This review discusses the recent advances made in our understanding of the signaling effectors of anoikis in prostate cancer and the approaches to translate these mechanistic insights into therapeutic benefits for reducing lethal disease outcomes (by overcoming anoikis resistance). The prostate tumor microenvironment is a highly dynamic landscape wherein the balance between androgen signaling, cell lineage changes, epithelial-mesenchymal transition (EMT), extracellular matrix interactions, actin cytoskeleton remodeling as well as metabolic changes, confer anoikis resistance and metastatic spread. Thus, these mechanisms also offer unique molecular treatment signatures, exploitation of which can prime prostate tumors to anoikis induction with a high translational significance.

Cofilin promotes vasculogenic mimicry by regulating the actin cytoskeleton in human breast cancer cells

Vasculogenic mimicry (VM) is the formation of microvascular channels by cancer cells. VM requires cellular processes that are regulated by changes in cellular migration and morphology. Cofilin (CFL), a key regulator of actin depolymerization, has been reported to affect malignant phenotypes of cancer. We show that treatment with inhibitors of actin dynamics suppresses VM in MDA-MB-231 human breast cancer cells. We established CFL-knockout (KO) MDA-MB-231 cells and found that VM was attenuated in CFL-KO cells. Although the re-expression of wild-type CFL restored VM in CFL-KO cells, inactive phosphomimetic CFL failed to do so. Collectively, our results demonstrate that CFL is a critical regulator of VM and implicate CFL as a novel therapeutic target for breast cancer.

Cofilin Acts as a Booster for Progression of Malignant Tumors Represented by Glioma

Cofilin, as a depolymerization factor of actin filaments, has been widely studied. Evidences show that cofilin has a role in actin structural reorganization and dynamic regulation. In recent years, several studies have demonstrated a regulatory role for cofilin in the migration and invasion mediated by cell dynamics and epithelial to mesenchymal transition (EMT)/EMT-like process, apoptosis, radiotherapy resistance, immune escape, and transcriptional dysregulation of malignant tumor cells, particularly glioma cells. On this basis, it is practical to evaluate cofilin as a biomarker for predicting tumor metastasis and prognosis. Targeting cofilin regulating kinases, Lin11, Isl-1 and Mec-3 kinases (LIM kinases/LIMKs) and their major upstream molecules inhibits tumor cell migration and invasion and targeting cofilin-mediated mitochondrial pathway induces apoptosis of tumor cells represent effective options for the development of novel anti-malignant tumor drug, especially anti-glioma drugs. This review explores the structure, general biological function, and regulation of cofilin, with an emphasis on the critical functions and prospects for clinical therapeutic applications of cofilin in malignant tumors represented by glioma.

Combinatorial approaches of nanotherapeutics for inflammatory pathway targeted therapy of prostate cancer

Prostate cancer (PC) is the most prevalent male urogenital cancer worldwide. PC patients presenting an advanced or metastatic cancer succumb to the disease, even after therapeutic interventions including radiotherapy, surgery, androgen deprivation therapy (ADT), and chemotherapy. One of the hallmarks of PC is evading immune surveillance and chronic inflammation, which is a major challenge towards designing effective therapeutic formulations against PC. Chronic inflammation in PC is often characterized by tumor microenvironment alterations, epithelial-mesenchymal transition and extracellular matrix modifications. The inflammatory events are modulated by reactive nitrogen and oxygen species, inflammatory cytokines and chemokines. Major signaling pathways in PC includes androgen receptor, PI3K and NF-κB pathways and targeting these inter-linked pathways poses a major therapeutic challenge. Notably, many conventional treatments are clinically unsuccessful, due to lack of targetability and poor bioavailability of the therapeutics, untoward toxicity and multidrug resistance. The past decade witnessed an advancement of nanotechnology as an excellent therapeutic paradigm for PC therapy. Modern nanovectorization strategies such as stimuli-responsive and active PC targeting carriers offer controlled release patterns and superior anti-cancer effects. The current review initially describes the classification, inflammatory triggers and major inflammatory pathways of PC, various PC treatment strategies and their limitations. Subsequently, recent advancement in combinatorial nanotherapeutic approaches, which target PC inflammatory pathways, and the mechanism of action are discussed. Besides, the current clinical status and prospects of PC homing nanovectorization, and major challenges to be addressed towards the advancement PC therapy are also addressed.

DPYSL2 interacts with JAK1 to mediate breast cancer cell migration

The intricate neuronal wiring during development requires cytoskeletal reorganization orchestrated by signaling cues. Because cytoskeletal remodeling is a hallmark of cell migration, we investigated whether metastatic cancer cells exploit axon guidance proteins to migrate. Indeed, in breast cancer patients, we found a significant correlation between mesenchymal markers and the expression of dihydropyrimidinase-like 2 (DPYSL2), a regulator of cytoskeletal dynamics in growing axons. Strikingly, DPYSL2 knockout in mesenchymal-like breast cancer cells profoundly inhibited cell migration, invasion, stemness features, tumor growth rate, and metastasis. Next, we decoded the molecular mechanism underlying this phenomenon and revealed an interaction between DPYSL2 and Janus kinase 1 (JAK1). This binding is crucial for activating signal transducer and activator of transcription 3 (STAT3) and the subsequent expression of vimentin, the promigratory intermediate filament. These findings identify DPYSL2 as a molecular link between oncogenic signaling pathways and cytoskeletal reorganization in migrating breast cancer cells.

Actin-binding Rho activating C-terminal like (ABRACL) transcriptionally regulated by MYB proto-oncogene like 2 (MYBL2) promotes the proliferation, invasion, migration and epithelial-mesenchymal transition of breast cancer cells

Breast cancer is the most common malignant tumor in females with high incidence and mortality. Actin-binding Rho activating C-terminal like (ABRACL) was highly expressed in several cancers. We aimed to investigate the function and mechanism of ABRACL in breast cancer. In this study, biological information analysis predicted the expression of ABRACL and MYB proto-oncogene-like 2 (MYBL2) in breast cancer tissues and their possible relationship. With the application of RT-qPCR and western blot, the mRNA and protein expression of ABRACL and MYBL2 in breast cancer cell lines were assessed. After ABRACL interference, an assessment of cell proliferation was carried out using cell counting kit (CCK)-8, colony formation, and western blot. The invasive and migratory abilities of cells were determined by transwell and wound healing assays. The epithelial-mesenchymal transition (EMT) process was assayed utilizing western blot. The relationship between ABRACL and MYBL2 was confirmed by luciferase reporter assay and chromatin immunoprecipitation (ChIP). The above experiments were done again after MYBL2 overexpression in breast cancer cells with ABRACL deletion. Results revealed that ABRACL and MYBL2 were highly expressed in breast cancer tissues and cells. ABRACL knockdown suppressed the proliferation, invasion, migration, and EMT of breast cancer cells. MYBL2 transcriptionally activated ABRACL. Besides, MYBL2 overexpression reversed the effects of ABRACL knockdown on cell malignant biological behaviors. To conclude, ABRACL could be transcriptionally regulated by MYBL2 to promote cell malignant biological behaviors in breast cancer cells, implying the potential of ABRACL being a promising target for the improvement of breast cancer therapy.

Tumoral Neuroligin 1 Promotes Cancer-Nerve Interactions and Synergizes with the Glial Cell Line-Derived Neurotrophic Factor

Many nervous proteins are expressed in cancer cells. In this report, we asked whether the synaptic protein neuroligin 1 (NLGN1) was expressed by prostatic and pancreatic carcinomas; in addition, given the tendency of these tumors to interact with nerves, we asked whether NLGN1 played a role in this process. Through immunohistochemistry on human tissue microarrays, we showed that NLGN1 is expressed by prostatic and pancreatic cancer tissues in discrete stages and tumor districts. Next, we performed in vitro and in vivo assays, demonstrating that NLGN1 promotes cancer cell invasion and migration along nerves. Because of the established role of the neurotrophic factor glial cell line-derived neurotrophic factor (GDNF) in tumor-nerve interactions, we assessed a potential NLGN1-GDNF cooperation. We found that blocking GDNF activity with a specific antibody completely inhibited NLGN1-induced in vitro cancer cell invasion of nerves. Finally, we demonstrated that, in the presence of NLGN1, GDNF markedly activates cofilin, a cytoskeletal regulatory protein, altering filopodia dynamics. In conclusion, our data further prove the existence of a molecular and functional cross-talk between the nervous system and cancer cells. NLGN1 was shown here to function along one of the most represented neurotrophic factors in the nerve microenvironment, possibly opening new therapeutic avenues.

Alterations in TGFβ signaling during prostate cancer progression

During prostate cancer progression, TGF-β acts as both a tumor suppressor and tumor promoter. TGF-β inhibits cell proliferation in normal and early-stage prostate cancer cells, but during later stages of the disease the cancer cells develop resistance to inhibitory effects on cell proliferation. In these cells, TGF-β promotes cancer progression due to its effects on epithelial to mesenchymal transition (EMT), cell migration and invasion, and immune suppression. The intracellular mechanisms involved in the development of resistance to TGF-β effects on cell proliferation are largely unknown. In this review, we summarized the roles of several intracellular proteins including PTEN, Id1 and JunD, which may play a role in this transition. The role of Ski/SnoN proteins in inhibition of Smad2/3 signaling is highlighted.

Sirolimus Suppresses Phosphorylation of Cofilin and Reduces Interstitial Septal Thickness in Sporadic Lymphangioleiomyomatosis

Sporadic lymphangioleiomyomatosis (S-LAM) is a rare lung disease characterized by the proliferation of smooth muscle-like LAM cells and progressive cystic destruction. Sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, has a proven efficacy in patients with LAM. However, the therapeutic mechanisms of sirolimus in LAM remain unclear. We aimed to evaluate sirolimus-related lung parenchymal changes and the potential effect in LAM cells and modulating pathological cystic destruction. Lung specimens were examined for histopathological changes by HMB45 staining and compared the LAM patients treated with and without sirolimus. We detected the overexpression of mTOR, HMB45, and phosphorylation of cofilin (p-cofilin) in LAM patients. Sirolimus showed efficacy in patients with LAM, who exhibited a reduced expression of mTOR and p-cofilin as well as reduced interstitial septal thickness. In addition, sirolimus suppresses mTOR and p-cofilin, thus suppressing the migration and proliferation of LAM cells isolated from the patient's lung tissue. This study demonstrates that interstitial septal thickness, as determined by histological structural analysis. Sirolimus effectively reduced the expression of p-cofilin and interstitial septal thickness, which may be a novel mechanism by sirolimus. Moreover, we develop a new method to isolate and culture the LAM cell, which can test the possibility of medication in vitro and impact this current study has on the LAM field. The development of approaches to interfere with mTOR-cofilin1-actin signaling may result in an option for S-LAM therapy.

Overexpressed Proteins in HCC Cell-Derived Exosomes, CCT8, and Cofilin-1 Are Potential Biomarkers for Patients with HCC

Protein markers of hepatocellular carcinoma (HCC)-derived exosomes (HEX) have not yet been fully evaluated. Here, we identified novel protein contents of HEX and their clinical significance as biomarkers. Exosomes were isolated from human HCC cell lines and an immortalized normal hepatocyte cell line. Proteomic analyses revealed 15 markedly overexpressed proteins in HEX. The clinical relevance of the 15 proteins was analyzed in public RNA-sequencing datasets, and 6 proteins were selected as candidate of potential biomarkers. Serum CCT8 and CFL1 were markedly overexpressed in test cohort (n = 8). In the validation cohort (n = 224), the area under the curve (AUC) of serum CCT8 and CFL1 for HCC diagnosis was calculated as 0.698 and 0.677, respectively, whereas that of serum alpha-fetoprotein (AFP) was 0.628. The combination of three serum markers (CCT8, CFL1, and AFP) demonstrated the highest AUC for HCC diagnosis. (AUC = 0.838, 95% confidence interval = 0.773–0.876) Furthermore, higher serum CCT8 and CFL1 concentrations were significantly associated with the presence of vascular invasion, advanced tumor stage, poor disease-free survival, and poor overall survival. Cofilin-1 and CCT8, enriched proteins in HEX, were identified as potential diagnostic and prognostic serum biomarkers for HCC patients.

Circulating Small Extracellular Vesicles Activate TYRO3 to Drive Cancer Metastasis and Chemoresistance

Extracellular vesicles (EV) in the tumor microenvironment have emerged as crucial mediators that promote proliferation, metastasis, and chemoresistance. However, the role of circulating small EVs (csEV) in cancer progression remains poorly understood. In this study, we report that csEV facilitate cancer progression and determine its molecular mechanism. csEVs strongly promoted the migration of cancer cells via interaction with phosphatidylserine of csEVs. Among the three TAM receptors, TYRO3, AXL, and MerTK, TYRO3 mainly interacted with csEVs. csEV-mediated TYRO3 activation promoted migration and metastasis via the epithelial-mesenchymal transition and stimulation of RhoA in invasive cancer cells. Additionally, csEV-TYRO3 interaction induced YAP activation, which led to increased cell proliferation and chemoresistance. Combination treatment with gefitinib and KRCT-6j, a selective TYRO3 inhibitor, significantly reduced tumor volume in xenografts implanted with gefitinib-resistant non-small cell lung cancer cells. The results of this study show that TYRO3 activation by csEVs facilitates cancer cell migration and chemoresistance by activation of RhoA or YAP, indicating that the csEV/TYRO3 interaction may serve as a potential therapeutic target for aggressive cancers in the clinic. SIGNIFICANCE: These findings demonstrate that circulating extracellular vesicles are a novel driver in migration and survival of aggressive cancer cells via TYRO3 activation. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/13/3539/F1.large.jpg.

Targeting the cytoskeleton against metastatic dissemination

Cancer is a pathology characterized by a loss or a perturbation of a number of typical features of normal cell behaviour. Indeed, the acquisition of an inappropriate migratory and invasive phenotype has been reported to be one of the hallmarks of cancer. The cytoskeleton is a complex dynamic network of highly ordered interlinking filaments playing a key role in the control of fundamental cellular processes, like cell shape maintenance, motility, division and intracellular transport. Moreover, deregulation of this complex machinery contributes to cancer progression and malignancy, enabling cells to acquire an invasive and metastatic phenotype. Metastasis accounts for 90% of death from patients affected by solid tumours, while an efficient prevention and suppression of metastatic disease still remains elusive. This results in the lack of effective therapeutic options currently available for patients with advanced disease. In this context, the cytoskeleton with its regulatory and structural proteins emerges as a novel and highly effective target to be exploited for a substantial therapeutic effort toward the development of specific anti-metastatic drugs. Here we provide an overview of the role of cytoskeleton components and interacting proteins in cancer metastasis with a special focus on small molecule compounds interfering with the actin cytoskeleton organization and function. The emerging involvement of microtubules and intermediate filaments in cancer metastasis is also reviewed.

Actin Cytoskeleton and Regulation of TGFβ Signaling: Exploring Their Links

Human tissues, to maintain their architecture and function, respond to injuries by activating intricate biochemical and physical mechanisms that regulates intercellular communication crucial in maintaining tissue homeostasis. Coordination of the communication occurs through the activity of different actin cytoskeletal regulators, physically connected to extracellular matrix through integrins, generating a platform of biochemical and biomechanical signaling that is deregulated in cancer. Among the major pathways, a controller of cellular functions is the cytokine transforming growth factor β (TGFβ), which remains a complex and central signaling network still to be interpreted and explained in cancer progression. Here, we discuss the link between actin dynamics and TGFβ signaling with the aim of exploring their aberrant interaction in cancer.

Unraveling the Molecular Tumor-Promoting Regulation of Cofilin-1 in Pancreatic Cancer

Cofilin-1 (CFL1) overexpression in pancreatic cancer correlates with high invasiveness and shorter survival. Besides a well-documented role in actin remodeling, additional cellular functions of CFL1 remain poorly understood. Here, we unraveled molecular tumor-promoting functions of CFL1 in pancreatic cancer. For this purpose, we first show that a knockdown of CFL1 results in reduced growth and proliferation rates in vitro and in vivo, while apoptosis is not induced. By mechanistic modeling we were able to predict the underlying regulation. Model simulations indicate that an imbalance in actin remodeling induces overexpression and activation of CFL1 by acting on transcription factor 7-like 2 (TCF7L2) and aurora kinase A (AURKA). Moreover, we could predict that CFL1 impacts proliferation and apoptosis via the signal transducer and activator of transcription 3 (STAT3). These initial model-based regulations could be substantiated by studying protein levels in pancreatic cancer cell lines and human datasets. Finally, we identified the surface protein CD44 as a promising therapeutic target for pancreatic cancer patients with high CFL1 expression.

Cofilin: A Promising Protein Implicated in Cancer Metastasis and Apoptosis

Cofilin is an actin-binding protein that regulates filament dynamics and depolymerization. The over-expression of cofilin is observed in various cancers, cofilin promotes cancer metastasis by regulating cytoskeletal reorganization, lamellipodium formation and epithelial-to-mesenchymal transition. Clinical treatment of cancer regarding cofilin has been explored in aspects of tumor cells apoptosis and cofilin related miRNAs. This review addresses the structure and phosphorylation of cofilin and describes recent findings regarding the function of cofilin in regulating cancer metastasis and apoptosis in tumor cells.

Cofilin-1, LIMK1 and SSH1 are differentially expressed in locally advanced colorectal cancer and according to consensus molecular subtypes

Background

Colorectal cancer (CRC) is among the deadliest cancers, wherein early dissemination of tumor cells, and consequently, metastasis formation, are the main causes of mortality and poor prognosis. Cofilin-1 (CFL-1) and its modulators, LIMK1/SSH1, play key roles in mediating the invasiveness by driving actin cytoskeleton reorganization in various cancer types. However, their clinical significance and prognostic value in CRC has not been fully explored. Here, we evaluated the clinical contribution of these actin regulators according to TNM and consensus molecular subtypes (CMSs) classification.

Methods

CFL-1, LIMK1 and SSH1 mRNA/protein levels were assessed by real-time PCR and immunohistochemical analyses using normal adjacent and tumor tissues obtained from a clinical cohort of CRC patients. The expression levels of these proteins were associated with clinicopathological features by using the chi square test. In addition, using RNA-Seq data of CRC patients from The Cancer Genome Atlas (TCGA) database, we determine how these actin regulators are expressed and distributed according to TNM and CMSs classification. Based on gene expression profiling, Kaplan–Meier survival analysis was used to evaluated overall survival.

Results

Bioinformatic analysis revealed that LIMK1 expression was upregulated in all tumor stages. Patients with high levels of LIMK1 demonstrated significantly lower overall survival rates and exhibited greater lymph node metastatic potential in a clinical cohort. In contrast, CFL-1 and SSH1 have expression downregulated in all tumor stages. However, immunohistochemical analyses showed that patients with high protein levels of CFL-1 and SSH1 exhibited greater lymph node metastatic potential and greater depth of local invasion. In addition, using the CMSs classification to evaluate different biological phenotypes of CRC, we observed that LIMK1 and SSH1 genes are upregulated in immune (CMS1) and mesenchymal (CMS4) subtypes. However, patients with high levels of LIMK1 also demonstrated significantly lower overall survival rates in canonical (CMS2), and metabolic (CMS3) subtypes.

Conclusions

We demonstrated that CFL-1 and its modulators, LIMK1/SSH1, are differentially expressed and associated with lymph node metastasis in CRC. Finally, this expression profile may be useful to predict patients with aggressive signatures, particularly, the immune and mesenchymal subtypes of CRC.

Heparan Sulfate Proteoglycans Can Promote Opposite Effects on Adhesion and Directional Migration of Different Cancer Cells

Heparan sulfate proteoglycans take part in crucial events of cancer progression, such as epithelial-mesenchymal transition, cell migration, and cell invasion. Through sulfated groups on their glycosaminoglycan chains, heparan sulfate proteoglycans interact with growth factors, morphogens, chemokines, and extracellular matrix (ECM) proteins. The amount and position of sulfated groups are highly variable, thus allowing differentiated ligand binding and activity of heparan sulfate proteoglycans. This variability and the lack of specific ligands have delayed comprehension of the molecular basis of heparan sulfate proteoglycan functions. Exploiting a tumor-targeting peptide tool that specifically recognizes sulfated glycosaminoglycans, we analyzed the role of membrane heparan sulfate proteoglycans in the adhesion and migration of cancer cell lines. Starting from the observation that the sulfated glycosaminoglycan-specific peptide exerts a different effect on adhesion, migration, and invasiveness of different cancer cell lines, we identified and characterized three cell migration phenotypes, where different syndecans are associated with alternative signaling for directional cell migration.

Involvement of Actin and Actin-Binding Proteins in Carcinogenesis

The actin cytoskeleton plays a crucial role in many cellular processes while its reorganization is important in maintaining cell homeostasis. However, in the case of cancer cells, actin and ABPs (actin-binding proteins) are involved in all stages of carcinogenesis. Literature has reported that ABPs such as SATB1 (special AT-rich binding protein 1), WASP (Wiskott-Aldrich syndrome protein), nesprin, and villin take part in the initial step of carcinogenesis by regulating oncogene expression. Additionally, changes in actin localization promote cell proliferation by inhibiting apoptosis (SATB1). In turn, migration and invasion of cancer cells are based on the formation of actin-rich protrusions (Arp2/3 complex, filamin A, fascin, α-actinin, and cofilin). Importantly, more and more scientists suggest that microfilaments together with the associated proteins mediate tumor vascularization. Hence, the presented article aims to summarize literature reports in the context of the potential role of actin and ABPs in all steps of carcinogenesis.

SOX11-induced decrease in vimentin and an increase in prostate cancer cell migration attributed to cofilin activity

SOX11 is a transcription factor in the SOX family of genes that regulate multiple cellular events by influencing the expression of key genes in developmental, physiological, and tumorigenic cells. To elucidate the role of SOX11 in prostate cancer cells, PC-3 prostate cancer cells were cloned (S6 and S9 cells) to highly express SOX11. We demonstrated that both S6 and S9 lose vimentin expression, acquiring epithelial marker proteins, which indicates the Epithelial state phenotype. S6 and S9 cells have cancer-promoting characteristics that include higher migratory properties compared with control cells. The mechanisms that are responsible for the enhanced migration are cofilin activity and keratin 18 expression. TCGA (The Cancer Genome Atlas) dataset analysis revealed that metastatic prostate cancer tumors tend to have more SOX11 gene amplification compared with primary tumors. These results suggest the tumor promotive role and epithelial protein induction of SOX11 in prostate cancer cell.

WD Repeat Domain 1 Deficiency Inhibits Neointima Formation in Mice Carotid Artery by Modulation of Smooth Muscle Cell Migration and Proliferation

The migration, dedifferentiation, and proliferation of vascular smooth muscle cells (VSMCs) are responsible for intimal hyperplasia, but the mechanism of this process has not been elucidated. WD repeat domain 1 (WDR1) promotes actin-depolymerizing factor (ADF)/cofilin-mediated depolymerization of actin filaments (F-actin). The role of WDR1 in neointima formation and progression is still unknown. A model of intimal thickening was constructed by ligating the left common carotid artery in Wdr1 deletion mice, and H&E staining showed that Wdr1 deficiency significantly inhibits neointima formation. We also report that STAT3 promotes the proliferation and migration of VSMCs by directly promoting WDR1 transcription. Mechanistically, we clarified that WDR1 promotes the proliferation and migration of VSMCs and neointima formation is regulated by the activation of the JAK2/STAT3/WDR1 axis.

LIMK2 promotes the metastatic progression of triple-negative breast cancer by activating SRPK1

Triple-negative breast cancer (TNBC) is a highly metastatic breast cancer subtype and due to the lack of hormone receptors and HER2 expression, TNBC has limited therapeutic options with chemotherapy being the primary choice for systemic therapy. LIM Domain Kinase 2 (LIMK2) is a serine/threonine kinase that plays an important role in the regulation of actin filament dynamics. Here, we show that LIM domain kinase 2 (LIMK2) is overexpressed in TNBC, and short-hairpin RNA (shRNA)-mediated LIMK2 knockdown or its pharmacological inhibition blocks metastatic attributes of TNBC cells. To determine the mechanism by which LIMK2 promotes TNBC metastatic progression, we performed stable isotope labeling by amino acids in cell culture (SILAC) based unbiased large-scale phosphoproteomics analysis. This analysis identified 258 proteins whose phosphorylation was significantly reduced due to LIMK2 inhibition. Among these proteins, we identified SRSF protein kinase 1 (SRPK1), which encodes for a serine/arginine protein kinase specific for the SR (serine/arginine-rich domain) family of splicing factors. We show that LIMK2 inhibition blocked SRPK1 phosphorylation and consequentially its activity. Furthermore, similar to LIMK2, genetic inhibition of SRPK1 by shRNAs or its pharmacological inhibition blocked the metastatic attributes of TNBC cells. Moreover, the pharmacological inhibition of LIMK2 blocked metastatic progression in mice without affecting primary tumor growth. In sum, these results identified LIMK2 as a facilitator of distal TNBC metastasis and a potential target for preventing TNBC metastatic progression.

Mechanical tumor microenvironment and transduction: cytoskeleton mediates cancer cell invasion and metastasis

Metastasis is a complicated, multistep process that is responsible for over 90% of cancer-related death. Metastatic disease or the movement of cancer cells from one site to another requires dramatic remodeling of the cytoskeleton. The regulation of cancer cell migration is determined not only by biochemical factors in the microenvironment but also by the biomechanical contextual information provided by the extracellular matrix (ECM). The responses of the cytoskeleton to chemical signals are well characterized and understood. However, the mechanisms of response to mechanical signals in the form of externally applied force and forces generated by the ECM are still poorly understood. Furthermore, understanding the way cellular mechanosensors interact with the physical properties of the microenvironment and transmit the signals to activate the cytoskeletal movements may help identify an effective strategy for the treatment of cancer. Here, we will discuss the role of tumor microenvironment during cancer metastasis and how physical forces remodel the cytoskeleton through mechanosensing and transduction.

Identification of cofilin-1 as a novel mediator for the metastatic potentials and chemoresistance of the prostate cancer cells

Prostate cancer (PCa) is the most common malignancy among men. Tumor metastasis and chemoresistance contribute to the major cause of the mortality. In this study, we compared the protein profiles of two prostate cancer cell lines with different metastatic potentials, and identified cofilin-1 (CFL1) was one of the most differentially expressed proteins between two cell lines. Further results suggested that cofilin-1 promoted the remodeling of F-actin cytoskeleton, and enhanced the proliferation, migration and invasion of the prostate cancer cells via activation of P38 MAPK signaling pathway. In addition, cofilin-1 elevated the expression and drug efflux activity of multidrug resistance protein 1 (MDR1) by P38 MAPK signaling pathway, resulting in decrease of the adriamycin-induced apoptosis as well as the lytic cell death, and the subsequent resistance against adriamycin. Collectively, cofilin-1 might serve as a novel target candidate for both inhibiting the metastasis and reversing the chemoresistance of PCa.

Paracrine and cell autonomous signalling in pancreatic cancer progression and metastasis

Pancreatic ductal adenocarcinoma (PDAC) shows remarkable propensity to metastasize. This predilection to escape from the primary tumor is driven by paracrine and autocrine mechanisms that guide cancer cells through a multi-step process concluding with colonization in distant tissues. Although cell-intrinsic features support the metastatic ability of cancer cells, permissive microenvironments within the primary organ and at sites of distant metastasis may be rate-limiting. Identification of cancer cell-extrinsic factors that regulate formation of these environments lend new therapeutic targets for intervening on the metastatic cascade. In addition, the bipolar, yet fundamental, role of the immune system in the metastatic process presents therapeutic opportunities. Herein, we review the current knowledge of the metastatic cascade in PDAC, and propose that genomically stable determinants of metastasis (e.g. the pro-metastatic niche and immune system) are actionable targets for preventing, containing, and treating metastasis in PDAC.

Diallyl disulfide induces downregulation and inactivation of cofilin 1 differentiation via the Rac1/ROCK1/LIMK1 pathway in leukemia cells

Cofilin is associated with cell differentiation; however, to the best of our knowledge, no data have indicated an association between the cofilin 1 pathway and leukemia cell differentiation. The present study investigated the involvement of the cofilin 1 signaling pathway in diallyl disulfide (DADS)-induced differentiation and the inhibitory effects on the proliferation, migration, and invasion of human leukemia HL-60 cells. First, it was identified that 8 µM DADS suppressed cell proliferation, migration and invasion, and induced differentiation based on the reduced nitroblue tetrazolium ability and increased CD11b and CD33 expression. DADS significantly downregulated the expression of cofilin 1 and phosphorylated cofilin 1 in HL-60 leukemia cells. Second, it was verified that silencing cofilin 1 markedly promoted 8 µM DADS-induced differentiation and the inhibitory effect on cell proliferation and invasion. Overexpression of cofilin 1 obviously suppressed 8 µM DADS-induced differentiation and the inhibitory effect on cell proliferation and invasion. Third, the present study examined the mechanisms by which 8 µM DADS decreases cofilin 1 expression and activation. The results revealed that 8 µM DADS inhibited the mRNA and protein expression of Rac1, Rho-associated protein kinase 1 (ROCK1) and LIM domain kinase 1 (LIMK1) as well as the phosphorylation of LIMK1 in HL-60 cells, while 8 µM DADS enhanced the effects of the Rac1-ROCK1-LIMK1 pathway in cells overexpressing cofilin 1 compared with that in control HL-60 cells. These results suggest that the anticancer function of DADS on HL-60 leukemia cells is regulated by the Rac1-ROCK1-LIMK1-cofilin 1 pathway, indicating that DADS could be a promising anti-leukemia therapeutic compound.

Integrated Therapeutic Targeting of the Prostate Tumor Microenvironment

Prostate cancer is a common and deadly cancer among men. The heterogeneity that characterizes prostate tumors contributes to clinical challenges in the diagnosis, prognosis, and treatment of this malignancy. While localized prostate cancer can be treated with surgery or radiotherapy, metastatic disease to the lymph nodes and the bone requires aggressive treatment with androgen deprivation treatment (ADT). Unfortunately, this often eventually progresses to metastatic castration-resistant prostate cancer (mCRPC). Advanced prostate cancer treatment today involves 1st- and 2nd-line taxane chemotherapy and 2nd-generation antiandrogens. The process of epithelial mesenchymal transition (EMT), during which epithelial cells lose their adhesions and their polarity, is a critical contributor to prostate cancer metastasis. In this article, we aim to integrate the current understanding of mechanisms dictating the dynamics of phenotypic EMT, with apoptosis outcomes in prostate tumors in response to antiandrogen and taxane chemotherapy for the treatment of advanced disease. Novel insights into the signaling mechanisms that target the functional interface between apoptosis and EMT will be considered in the context of potential clinical markers of tumor prognosis, as well as for effective therapeutic targeting of α- and β- adrenergic signaling (by novel and existing chemotherapeutic agents and antiandrogens). Interfering with EMT and apoptosis simultaneously toward eradicating the tumor mass is of major significance in combating the lethal disease and increasing patient survival.

Tissue microarray analysis reveals that cofilin expression is a poor prognostic factor in juvenile nasopharyngeal angiofibroma

BACKGROUND

Juvenile nasopharyngeal angiofibroma (JNA) has a high recurrence rate after surgery. Cofilin overexpression is associated with increased tumor cell metastasis, and progression of various human cancers. However, studies on cofilin expression in JNA are rare. The purpose of this study was to investigate the expression and localization of cofilin in a tissue microarray (TMA) of JNA specimens. In addition, we also analyzed its correlation with clinicopathological features and recurrence.

METHODS

Immunohistochemistry was performed to detect cofilin expression in a TMA of samples from 70 JNA patients and 10 control subjects. The association between clinicopathological variables and cofilin immunostaining was analyzed using Pearson's chi-square test. Kaplan-Meier survival analysis was used to calculate the disease-free survival rate, and investigate the effect of cofilin expression on time to recurrence (TTR) in JNA patients. The Cox regression model was used for multivariate survival analysis.

RESULTS

Cofilin was detected in irregular smooth muscle cells, pericytes, less differentiated stromal cells, and plump cells, but not in inactive fibroblasts and mature vascular endothelial cells of JNA specimens. The presence of cofilin in JNA was correlated with tumor stage (p = 0.012) and volume of intraoperative hemorrhage (p < 0.001). JNA patients with high cofilin expression had a higher recurrence rate than those with low cofilin expression (p = 0.012). Cofilin expression and patient's age were significant predictors of TTR, and cofilin was a better predictor for disease recurrence (area under the receiver operating curve [AUROC; 0.711; p = 0.005) than other clinicopathological features.

CONCLUSION

Cofilin is an independent prognostic marker for JNA patients who have undergone surgical treatment and may represent a novel therapeutic target for extensive JNA.

Differential Expression Pattern of Epithelial Mesenchymal Transition Gens: AXL, GAS6, Claudin-1, and Cofilin-1, in Different Stages of Epithelial Ovarian Cancer

BACKGROUND

Epithelial ovarian cancer (EOC), is the fatal form of gynecological cancer. Almost 70% of ovarian cancer patients are detected at an advanced stage (III-IV) with metastases. Epithelial-mesenchymal transition (EMT) is a critical process associated with metastasis. This study investigated the expression levels of AXL, GAS6, Claudin-1, and Cofilin-1, as genes involved in EMT in relation to clinicopathologic features in ovarian cancer patients.

METHODS

In this descriptive study, 78 ovarian epithelial cancer patients were enrolled. Samples were provided by the Iran National Tumor Bank, founded by the Cancer Institute of Tehran University of Medical Sciences in 2017. The expression levels of AXL, GAS6, Claudin-1, and Cofilin-1 genes were investigated in a fresh, frozen tumor sample and normal adjacent tissue by real-time PCR (RT-PCR).

RESULTS

Findings showed a significant relationship between the overexpression of AXL and TNM staging (P=0.03). The expression level of GAS6 decreased in more advanced stages (P=0.01). There is a negative relationship between Cofilin-1 expression level and TNM staging (P=0.002). Claudin-1 expression level was higher in low stages compared with that in high stages (P=0.01). There was no relationship between gene expression levels of target genes with size and grade of the tumor.

CONCLUSION

Given the importance of these genes in EMT, alteration in their expression pattern can contribute to the progression of the disease and distant metastasis of cancer cells. Additionally, knowing the alteration pattern of these genes expression can help to better understanding and prediction of the prognosis of EOC.

Predictive and targeting value of IGFBP-3 in therapeutically resistant prostate cancer

BACKGROUND

Our previous studies demonstrated that a novel quinazoline derivative, DZ-50, inhibited prostate cancer epithelial cell invasion and survival by targeting insulin-like-growth factor binding protein-3 (IGFBP-3) and mediating epithelial-mesenchymal transition (EMT) conversion to mesenchymal-epithelial transition (MET). This study investigated the therapeutic value of DZ-50 agent in in vitro and in vivo models of advanced prostate cancer and the ability of the compound to overcome resistance to antiandrogen (enzalutamide) in prostate tumors.

APPROACH

LNCaP and LNCaP-enzalutamide resistant human prostate cancer (LNCaP-ER) cells, as well as 22Rv1 and enzalutamide resistant, 22Rv1-ER were used as cell models. The effects of DZ-50 and the antiandrogen, enzalutamide (as single agents or in combination) on cell death, EMT-MET interconversion, and expression of IGFBP3 and the androgen receptor (AR), were examined. The TRAMP mouse model of prostate cancer progression was used as a pre-clinical model. Transgenic mice (20-wks of age) were treated with DZ-50 (100 mg/kg for 2 wks, oral gavage daily) and prostate tumors were subjected to immunohistochemical assessment of apoptosis, cell proliferation, markers of EMT and differentiation and IGFBP-3 and AR expression. A tissue microarray (TMA) was analyzed for expression of IGBP-3, the target of DZ-50 and its association with tumor progression and biochemical recurrence.

RESULTS

We found that treatment with DZ-50 enhanced the anti-tumor response to the antiandrogen via promoting EMT to MET interconversion, in vitro. This DZ-50-mediated phenotypic reversal to MET leads to prostate tumor re-differentiation in vivo, by targeting nuclear IGFBP-3 expression (without affecting AR). Analysis of human prostate cancer specimens and TCGA patient cohorts revealed that overexpression of IGBP-3 protein correlated with tumor recurrence and poor patient survival.

CONCLUSIONS

These findings provide significant new insights into (a) the predictive value of IGFBP-3 in prostate cancer progression and (b) the antitumor action of DZ-50, [in combination or sequencing with enzalutamide] as a novel approach for the treatment of therapeutically resistant prostate cancer.

New Insights into the Role of Polybromo-1 in Prostate Cancer

The human protein Polybromo-1 (PBMR1/BAF180) is a component of the SWI/SNF chromatin-remodeling complex that has been reported to be deregulated in tumors. However, its role in prostate cancer (PCa) is largely unknown. In this study, we described the PBRM1 transcriptional levels and the protein expression/localization in tissues of PCa patients and in prostatic cell lines. Increased PBRM1 mRNA levels were found in PCa samples, when compared to benign disease, and were correlated with higher Gleason score. We also verified that only the nuclear localization of PBRM1 protein is correlated with a more aggressive disease and high Prostate-Specific Antigen (PSA) levels in tissue microarrays. Intriguing expression patterns of mRNA and protein were identified in the cell lines. Although PBRM1 protein was restricted to the nuclei, in tumor cell lines in non-neoplastic cells, it was also present in vesicular-like structures that were dispersed within the cytoplasm. We knocked-down PBRM1 in the castration-resistant PCa (CRPC) cell line PC-3 and we verified that PBRM1 promotes the expression of several markers of aggressiveness, including EpCAM, TGF-β, and N-Cadherin. Therefore, our data supported the hypothesis that PBRM1 displays a pivotal role in the promotion and maintenance of the malignant behavior of PCa, especially in CRPC.

Cytoskeleton actin-binding proteins in clinical behavior of pituitary tumors

Although generally benign, pituitary tumors are frequently locally invasive, with reduced success of neurosurgery and unresponsive to pharmacological treatment with somatostatin or dopamine analogues. The molecular basis of the different biological behavior of pituitary tumors are still poorly identified, but a body of work now suggests that the activity of specific cytoskeleton proteins is a key factor regulating both the invasiveness and drug resistance of these tumors. This review recapitulates the experimental evidence supporting a role for the actin-binding protein filamin A (FLNA) in the regulation of somatostatin and dopamine receptors expression and signaling in pituitary tumors, thus in determining the responsiveness to currently used drugs, somatostatin analogues and dopamine receptor type 2 agonists. Regarding the regulation of invasive behavior of pituitary tumoral cells, we bring evidence to the role of the actin-severing protein cofilin, whose activation status may be modulated by dopaminergic and somatostatinergic drugs, through FLNA involvement. Molecular mechanisms involved in the regulation of FLNA expression and function in pituitary tumors will also be discussed.

Prostate tumor neuroendocrine differentiation via EMT: The road less traveled

The long-standing challenge in the treatment of prostate cancer is to overcome therapeutic resistance during progression to lethal disease. Aberrant transforming-growth factor-β (TGF-β) signaling accelerates prostate tumor progression in a transgenic mouse model via effects on epithelial-mesenchymal transition (EMT), and neuroendocrine differentiation driving tumor progression to castration-resistant prostate cancer (CRPC). Neuroendocrine prostate cancer (NEPC) is highly aggressive exhibiting reactivation of developmental programs associated with EMT induction and stem cell-like characteristics. The androgen receptor (AR) is a critical driver of tumor progression as well as therapeutic response in patients with metastatic CRPC. The signaling interactions between the TGF-β mechanistic network and AR axis impact the EMT phenotypic conversions, and perturbation of epithelial homeostasis via EMT renders a critical venue for epithelial derived tumors to become invasive, acquire the neuroendocrine phenotype, and rapidly metastasize. Combinations of microtubule targeting taxane chemotherapy and androgen/AR targeting therapies have survival benefits in CRPC patients, but therapeutic resistance invariability develops, leading to mortality. Compelling evidence from our group recently demonstrated that chemotherapy (cabazitaxel, second line taxane chemotherapy), or TGF-β receptor signaling targeted therapy, caused reversion of EMT to mesenchymal-epithelial transition and tumor re-differentiation, in in vitro and in vivo prostate cancer models. In this review, we discuss the functional contribution of EMT dynamic changes to the development of the neuroendocrine phenotype-the newly characterized pathological feature of prostate tumors in the context of the tumor microenvironment-navigated cell lineage changes and the role of this neuroendocrine phenotype in metastatic progression and therapeutic resistance.

TGF-β receptor I inhibitor enhances response to enzalutamide in a pre-clinical model of advanced prostate cancer

BACKGROUND

Prostate cancer progression is navigated by the androgen receptor (AR) and transforming-growth factor-β (TGF-β) signaling. We previously demonstrated that aberrant TGF-β signaling accelerates prostate tumor progression in a transgenic mouse model of prostate cancer via effects on epithelial-mesenchymal transition (EMT), driving castration-resistant prostate cancer (CRPC).

METHODS

This study examined the antitumor effect of the combination of TGF-β receptor I (TβRI) inhibitor, galunisertib, and FDA-approved antiandrogen enzalutamide, in our pre-clinical model. Age-matched genotypically characterized DNTGFβRII male mice were treated with either galunisertib and enzalutamide, in combination or as single agents in three "mini"-trials and the effects on tumor growth, phenotypic EMT, and actin cytoskeleton were evaluated.

RESULTS

Galunisertib in combination with enzalutamide significantly suppressed prostate tumor growth, by increasing apoptosis and decreasing cell proliferation of tumor cell populations compared to the inhibitor as a monotherapy (P < 0.05). The combination treatment dramatically reduced cofilin levels, actin cytoskeleton regulator, compared to single agents. Treatment with galunisertib targeted nuclear Smad4 protein (intracellular TGF-β effector), but had no effect on nuclear AR. Consequential to TGF-β inhibition there was an EMT reversion to mesenchymal-epithelial transition (MET) and re-differentiation of prostate tumors. Elevated intratumoral TGF-β1 ligand, in response to galunisertib, was blocked by enzalutamide.

CONCLUSION

Our results provide novel insights into the therapeutic value of targeting TGF-β signaling to overcome resistance to enzalutamide in prostate cancer by phenotypic reprogramming of EMT towards tumor re-differentiation and cytoskeleton remodeling. This translational work is significant in sequencing TGF-β blockade and antiandrogens to optimize therapeutic response in CRPC.

Study of cofilin 1 gene expression in colorectal cancer

Background

Colorectal cancer (CRC) is one of the most prevalent malignancies worldwide. Cofilin is a key regulatory protein in the dynamics of actin filaments. Previous studies have shown cofilin 1's major role in cell migration process and its role in tumor cell migration and invasion. Therefore, cofilin 1 may have the potential as a novel diagnostic tumor marker in various cancers. In this study, differential expression of CFL1 in CRC tissues in comparison with adjacent non-tumor tissues was investigated and the diagnostic value of this protein in CRC was evaluated.

Methods

Synthesized cDNA from extracted RNAs of 30 patients were subjected to qRT-PCR to quantify relative expression of cofilin 1. The relationship between cofilin 1 expression and clinicopathological features of patients were studied too.

Results

The study showed significant upregulation of cofilin 1 in CRC tissue samples compared to adjacent non-tumor tissue samples (P<0.05). The receiver operating characteristic curve analysis showed higher area under the curve (0.85). There was no significant correlation between cofilin 1 expression levels and clinicopathological features of patients.

Conclusions

According to the obtained results, cofilin 1 can serve as a candidate for clinically useful diagnostic biomarker or therapeutic target for CRC.

Alendronate-induced disruption of actin cytoskeleton and inhibition of migration/invasion are associated with cofilin downregulation in PC-3 prostate cancer cells

Bisphosphonates are used for prevention of osteoporosis and metastatic bone diseases. Anti-invasive effects on various cancer cells have also been reported, but the mechanisms involved are not well-understood. We investigated the effects of the nitrogen-containing bisphosphonate alendronate (ALN) on the regulation of actin cytoskeleton in PC-3 cells. We analyzed the ALN effect on the organization and the dynamics of actin, and on the cytoskeleton-related regulatory proteins cofilin, p21-associated kinase 2 (PAK2), paxillin and focal adhesion kinase. Immunostainings of cofilin in ALN-treated PC-3 cells and xenografts were performed, and the role of cofilin in ALN-regulated F-actin organization and migration/invasion in PC-3 cells was analyzed using cofilin knockdown and transfection. We demonstrate that disrupted F-actin organization and decreased cell motility in ALN-treated PC-3 cells were associated with decreased levels of total and phosphorylated cofilin. PAK2 levels were also lowered but adhesion-related proteins were not altered. The knockdown of cofilin similarly impaired F-actin organization and decreased invasion of PC-3 cells, whereas in the cells transfected with a cofilin expressing vector, ALN treatment did not decrease cellular cofilin levels and migration as in mock transfected cells. ALN also reduced immunohistochemical staining of cofilin in PC-3 xenografts. Our results suggest that reduction of cofilin has an important role in ALN-induced disruption of the actin cytoskeleton and inhibition of the PC-3 cell motility and invasion. These data also support the idea that the nitrogen-containing bisphosphonates could be efficacious in inhibition of prostate cancer invasion and metastasis, if delivered in a pharmacological formulation accessible to the tumors.

WDR1 Promotes Cell Growth and Migration and Contributes to Malignant Phenotypes of Non-small Cell Lung Cancer through ADF/cofilin-mediated Actin Dynamics

The characteristic of carcinoma is cell migration and invasion, which involve in strong actin dynamics. Regulations of actin dynamics have been implicated in cancer cell migration and tumor progression. WDR1 (WD-repeat domain 1) is a major cofactor of the actin depolymerizing factor (ADF)/cofilin, strongly accelerating ADF/cofilin-mediated actin disassembly. The role of WDR1 in non-small cell lung cancer (NSCLC) progression has been unknown. Here, we show that the expression levels of WDR1 are increased in human NSCLC tissues compared with adjacent non-tumor tissues, and high WDR1 level correlates with poor prognosis in NSCLC patients. Knockdown of WDR1 in NSCLC cells significantly inhibits cell migration, invasion, EMT process and tumor cell growth in vitro and in vivo. Otherwise, overexpression of WDR1 promotes NSCLC cell proliferation and migration. Mechanically, our data suggested WDR1 regulated tumor cells proliferation and migration might through actin cytoskeleton-mediated regulation of YAP, and we demonstrated that WDR1 contributes to NSCLC progression through ADF/cofilin-mediated actin disassembly. Our findings implicate that the ADF/cofilin-WDR1-actin axis as an activator of malignant phenotype that will be a promising therapeutic target in lung cancer.