Irigenin, a novel lead from Western Himalayan chemiome inhibits Fibronectin-Extra Domain A induced metastasis in Lung cancer cells

EDA Fibronectin Microarchitecture and YAP Translocation during Wound Closure

Fibronectin (Fn) is an extracellular matrix glycoprotein with mechanosensitive structure-function. Extra domain A (EDA) Fn, a Fn isoform, is not present in adult tissue but is required for tissue repair. Curiously, EDA Fn is linked to both regenerative and fibrotic tissue repair. Given that Fn mechanoregulates cell behavior, EDA Fn organization during wound closure might play a role in mediating these differing responses. One mechanism by which cells sense and respond to their microenvironment is by activating a transcriptional coactivator, yes-associated protein (YAP). Interestingly, YAP activity is not only required for wound closure but similarly linked to both regenerative and fibrotic repair. Therefore, this study aims to evaluate how, during normal and fibrotic wound closure, EDA Fn organization might modulate YAP translocation by culturing human dermal fibroblasts on polydimethylsiloxane substrates mimicking normal (soft: 18 kPa) and fibrotic (stiff: 146 kPa) wounded skin. On stiffer substrates mimicking fibrotic wounds, fibroblasts assembled an aligned EDA Fn matrix comprising thinner fibers, suggesting increased microenvironmental tension. To evaluate if cell binding to the EDA domain of Fn was essential to overall matrix organization, fibroblasts were treated with Irigenin, which inhibits binding to the EDA domain within Fn. Blocking adhesion to EDA led to randomly organized EDA Fn matrices with thicker fibers, suggesting reduced microenvironmental tension even during fibrotic wound closure. To evaluate whether YAP signaling plays a role in EDA Fn organization, fibroblasts were treated with CA3, which suppresses YAP activity in a dose-dependent manner. Treatment with CA3 also led to randomly organized EDA Fn matrices with thicker fibers, suggesting a potential connected mechanism of reducing tension during fibrotic wound closure. Next, YAP activity was assessed to evaluate the impact of EDA Fn organization. Interestingly, fibroblasts migrating on softer substrates mimicking normal wounds increased YAP activity, but on stiffer substrates, they decreased YAP activity. When fibroblasts on stiffer substrates were treated with Irigenin or CA3, fibroblasts increased YAP activity. These results suggest that there may be disrupted signaling between EDA Fn organization and YAP translocation during fibrotic wound closure that could be restored when reestablishing normal EDA Fn matrix organization to instead drive regenerative wound repair.

Drug repurposing for targeting fibronectin in treatment of endometriosis and cancers

Increased concentrations of the fibronectin glycoprotein can cause ectopic tissue growth patients with endometriosis and the formation of various cancerous tumors. Furthermore, fibronectin binding to its receptors from the EDA (Extra Domain A) region contributes to promote tumorigenesis, metastasis and vasculogenesis. Thus, the EDA region can be considered a unique target for therapeutic intervention. Therefore, the present study used computational methods to identify the best fibronectin inhibitor(s) among FDA-approved drugs. First, docking-based virtual screening was performed using PyRx 0.8. Next, FDA-approved drugs that obtained favorable results in the docking phase were selected for further studies and analysis using molecular dynamics (MD) simulation. The preliminary findings of the virtual screening showed that 17 FDA-approved drugs (from 2471) had more favorable energy with their binding energy less than -9 kcal/mol. The MD simulation results of these 17 drugs showed that Avapritinib had a lower RMSD value and higher binding energy and hydrogen bonding than the other complexes in the EDA domain. Also, analyses related to the second structure changes displayed that Avapritinib in the EDA domain led to more changes in the second structure. According to the results, the anticancer drug Avapritinib forms a more stable complex with fibronectin than other FDA-approved drugs. Furthermore, this drug leads to more changes in the second EDA structure, which may have more serious potential for inhibiting EDA fibronectin.Communicated by Ramaswamy H. Sarma.

Integrating serum metabolomics analysis and network pharmacology to reveal the potential mechanism of Shengmai Jianghuang San in the treatment of nasopharyngeal carcinoma

Shengmai Jianghuang San (SMJHS) is a traditional Chinese herbal compound reported to inhibit Nasopharyngeal Carcinoma (NPC) progression and enhance radiosensitivity. However, the specific active ingredients and regulatory mechanisms of SMJHS against NPC, particularly under hypoxic conditions, remain unclear. In this study, Sprague-Dawley (SD) rats were gavaged with Shengmai Jianghuang San (SMJHS), and their blood was collected from the abdominal aorta. UHPLC-Q-Exactive orbitrap MS/MS was used to identify the metabolite profiles of SMJHS drug-containing serum. A molecular network of the active compositions in SMJHS targeting NPC was constructed through network pharmacology and molecular docking. The HIF-1α/VEGF pathway was in key positions. The effects of SMJHS on the proliferation, migration, and radiosensitivity of hypoxic NPC cells were assessed by in vitro experiments. NPC cell lines stably overexpressing HIF-1α were established using a lentivirus to investigate the regulation of HIF-1α/VEGF signaling in hypoxic NPC cells by SMJHS. Through a combination of network pharmacological analysis, cellular biofunctional validation, and molecular biochemical experiments, our study found that SMJHS had an anti-proliferative effect on NPC cells cultured under hypoxic conditions, inhibiting their migration and increasing their radiosensitivity. Additionally, SMJHS suppressed the expression of HIF-1α and VEGFA, exhibiting potential as an effective option for improving NPC treatment.

Formation of an invasion-permissive matrix requires TGFβ/SNAIL1-regulated alternative splicing of fibronectin

BACKGROUND

As in most solid cancers, the emergence of cells with oncogenic mutations in the mammary epithelium alters the tissue homeostasis. Some soluble factors, such as TGFβ, potently modify the behavior of healthy stromal cells. A subpopulation of cancer-associated fibroblasts expressing a TGFβ target, the SNAIL1 transcription factor, display myofibroblastic abilities that rearrange the stromal architecture. Breast tumors with the presence of SNAIL1 in the stromal compartment, and with aligned extracellular fiber, are associated with poor survival prognoses.

METHODS

We used deep RNA sequencing and biochemical techniques to study alternative splicing and human tumor databases to test for associations (correlation t-test) between SNAIL1 and fibronectin isoforms. Three-dimensional extracellular matrices generated from fibroblasts were used to study the mechanical properties and actions of the extracellular matrices on tumor cell and fibroblast behaviors. A metastatic mouse model of breast cancer was used to test the action of fibronectin isoforms on lung metastasis.

RESULTS

In silico studies showed that SNAIL1 correlates with the expression of the extra domain A (EDA)-containing (EDA+) fibronectin in advanced human breast cancer and other types of epithelial cancers. In TGFβ-activated fibroblasts, alternative splicing of fibronectin as well as of 500 other genes was modified by eliminating SNAIL1. Biochemical analyses demonstrated that SNAIL1 favors the inclusion of the EDA exon by modulating the activity of the SRSF1 splicing factor. Similar to Snai1 knockout fibroblasts, EDA- fibronectin fibroblasts produce an extracellular matrix  that does not sustain TGFβ-induced fiber organization, rigidity, fibroblast activation, or tumor cell invasion. The presence of EDA+ fibronectin changes the action of metalloproteinases on fibronectin fibers. Critically, in an mouse orthotopic breast cancer model, the absence of the fibronectin EDA domain completely prevents lung metastasis.

CONCLUSIONS

Our results support the requirement of EDA+ fibronectin in the generation of a metastasis permissive stromal architecture in breast cancers and its molecular control by SNAIL1. From a pharmacological point of view, specifically blocking EDA+ fibronectin deposition could be included in studies to reduce the formation of a pro-metastatic environment.

Dissection of paracrine/autocrine interplay in lung tumor microenvironment mimicking cancer cell-monocyte co-culture models reveals proteins that promote inflammation and metastasis

BACKGROUND

Tumor cell-monocyte interactions play crucial roles in shaping up the pro-tumorigenic phenotype and functional output of tumor-associated macrophages. Within the tumor microenvironment, such heterotypic cell-cell interactions are known to occur via secretory proteins. Secretory proteins establish a diabolic liaison between tumor cells and monocytes, leading to their recruitment, subsequent polarization and consequent tumor progression.

METHODS

We co-cultured model lung adenocarcinoma cell line A549 with model monocytes, THP-1 to delineate the interactions between them. The levels of prototypical pro-inflammatory cytokines like TNF-𝛼, IL-6 and anti-inflammatory cytokines like IL-10 were measured by ELISA. Migration, invasion and attachment independence of lung cancer cells was assessed by wound healing, transwell invasion and colony formation assays respectively. The status of EMT was evaluated by immunofluorescence. Identification of secretory proteins differentially expressed in monocultures and co-culture was carried out using SILAC LC-MS/MS. Various insilico tools like Cytoscape, Reacfoam, CHAT and Kaplan-Meier plotter were utilized for association studies, pathway analysis, functional classification, cancer hallmark relevance and predicting the prognostic potential of the candidate secretory proteins respectively.

RESULTS

Co-culture of A549 and THP-1 cells in 1:10 ratio showed early release of prototypical pro-inflammatory cytokines TNF-𝛼 and IL-6, however anti-inflammatory cytokine, IL-10 was observed to be released at the highest time point. The conditioned medium obtained from this co-culture ratio promoted the migration, invasion and colony formation as well as the EMT of A549 cells. Co-culturing of A549 with THP-1 cells modulated the secretion of proteins involved in cell proliferation, migration, invasion, EMT, inflammation, angiogenesis and inhibition of apoptosis. Among these proteins Versican, Tetranectin, IGFBP2, TUBB4B, C2 and IFI30 were found to correlate with the inflammatory and pro-metastatic milieu observed in our experimental setup. Furthermore, dysregulated expression of these proteins was found to be associated with poor prognosis and negative disease outcomes in lung adenocarcinoma compared to other cancer types. Pharmacological interventions targeting these proteins may serve as useful therapeutic approaches in lung adenocarcinoma.

CONCLUSION

In this study, we have demonstrated that the lung cancer cell-monocyte cross-talk modulates the secretion of IFI30, RNH1, CLEC3B, VCAN, IGFBP2, C2 and TUBB4B favoring tumor growth and metastasis.

Shielding and nurturing: Fibronectin as a modulator of cancer drug resistance

Resistance to chemotherapy and targeted therapies constitute a common hallmark of most cancers and represent a dominant factor fostering tumor relapse and metastasis. Fibronectin, an abundant extracellular matrix glycoprotein, has long been proposed to play an important role in the pathobiology of cancer. Recent research has unraveled the role of Fibronectin in the onset of chemoresistance against a variety of antineoplastic drugs including DNA-damaging agents, hormone receptor antagonists, tyrosine kinase inhibitors, microtubule destabilizing agents, etc. The current review summarizes the role played by Fibronectin in mediating drug resistance against diverse anticancer drugs. We have also discussed how the aberrant expression of Fibronectin drives the oncogenic signaling pathways ultimately leading to drug resistance through the inhibition of apoptosis, promotion of cancer cell growth and proliferation.

Identification of novel inhibitors of tetranectin-plasminogen interaction to suppress breast cancer invasion: an integrated computational and cell-based investigation

Tetranectin-plasminogen interaction plays a defining role in extracellular matrix degradation, enabling tumor cell invasion and metastasis. This interaction occurs via the carbohydrate recognition domain (CRD) and Kringle 4 domain of tetranectin and plasminogen, respectively, leading to activation of the plasminogen-cascade that triggers the proteolytic processes. Thus targeting this interaction represents an important strategy to suppress tumor cell migration and invasion. In this direction, we attempted to target the CRD of tetranectin to inhibit its interaction with the Kringle-4 domain of plasminogen using natural bioactive compounds. A cheminformatics pipeline for drug designing and screening was utilized to obtain lead compound(s) that exhibit conformationally and energetically viable CRD binding. Out of 206 compounds screened, diosgenin and scytonemin displayed the most favorable interactions with CRD. Short-term molecular dynamics simulations of 20 ns were employed to further study the conformational stability of both compounds with tetranectin CRD which reflected at the increased stability of diosgenin in the CRD binding pocket compared to scytonemin. Finally, an extended molecular dynamic simulation of 100 ns affirmed the robust and stable interaction of diosgenin with CRD. Furthermore, diosgenin was observed to exert a pronounced anti-proliferative effect on high tetranectin-expressing MDA-MB-231 breast cancer cells. The inhibitory effect of diosgenin on the tetranectin-plasminogen interaction was corroborated by the reduced migration and invasiveness of MDA-MB-231 cells under diosgenin treatment. Overall the study presents an alternate and safer approach to impede breast cancer metastasis and delineates the novel anti-metastatic activity of diosgenin.Communicated by Ramaswamy H. Sarma.

Irigenin inhibits glioblastoma progression through suppressing YAP/β-catenin signaling

Glioblastoma (GBM) is the most malignant glioma in brain tumors with low survival and high recurrence rate. Irigenin, as an isoflavone compound extracted from Shegan, has shown many pharmacological functions such as antioxidant, anti-inflammatory and anti-tumor. However, the effects of irigenin on GBM cells and the related molecular mechanisms remain unexplored. In this study, we found that irigenin inhibited the proliferation of GBM cells in a dose-dependent manner by several assays in vitro. Subsequently, we found that irigenin arrested cell cycle at G2/M phase and induced apoptosis of GBM cells in vitro. In addition, irigenin inhibited the migration of GBM cells. Mechanically, we found that irigenin treatment decreased the expression of YAP (yes-associated protein), suppressed β-catenin signaling. Furthermore, overexpression of YAP partially restored the anti-tumor effects of irigenin on GBM cells in vitro. Finally, we found that irigenin inhibited the growth of tumor in GBM xenograft mice model through inactivation of YAP. Taken together, these results suggest that irigenin exerts its anticancer effects on GBM via inhibiting YAP/β-catenin signaling, which may provide a new strategy for the treatment of GBM.

Irigenin, a novel lead from Iris confusa for management of Helicobacter pylori infection with selective COX-2 and HpIMPDH inhibitory potential

The development of new natural drugs for Helicobacter pylori (H. pylori) management has recently received significant attention. Iris confusa (I. confusa) was long used for the treatment of bacterial infections and gastritis. This study aimed at evaluating its effect on management of H. pylori infection and exploring its bioactive metabolites. The inhibitory potential of the polar (PF), non-polar (NPF) fractions and the isolated compounds against H. pylori using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay in addition to their cyclooxygenases (COX-1 and COX-2), and nitric oxide (NO) inhibitory activities were assessed. The most biologically active compound was tested for its selective H. pylori inosine-5'-monophosphate dehydrogenase (HpIMPDH) inhibitory potential. Chromatographic purification of PF and NPF allowed isolation of tectoridin, orientin, irigenin, tectorigenin, isoarborinol and stigmasterol. The PF exhibited significant anti-H. pylori (MIC 62.50 µg/mL), COX-1, COX-2 (IC50 of 112.08 ± 0.60 and 47.90 ± 1.50 µg/mL respectively, selectivity index SI of 2.34), and NO (IC50 47.80 ± 0.89 µg/mL) inhibitory activities, while irigenin was the most potent isolated compound. Irigenin was found to have a promising activity against HpIMPDH enzyme (IC50 of 2.07 ± 1.90 μM) with low activity against human hIMPDH2 (IC50 > 10 μM) than clarithromycin, assuring its selectivity. Overall, I. confusa and its isolated compounds may serve as a potential source of plant-based drugs for H. pylori control. This study scientifically validated the claimed anti-bacterial activity of I. confusa and revealed irigenin potential as a novel lead exhibiting anti H. pylori activity in a first record.

UGT1A1 and UGT1A9 Are Responsible for Phase II Metabolism of Tectorigenin and Irigenin In Vitro

Tectorigenin and irigenin are biologically active isoflavones of Belamcanda chinensis (L.) DC. Previous studies indicated that both compounds could be metabolized in vivo; however, the kinetic parameters of enzymes involved in the metabolization of tectorigenin and irigenin have not been identified. The aim of this study was to investigate UGTs involved in the glucuronidation of tectorigenin and irigenin and determine enzyme kinetic parameters using pooled human liver microsomes (HLMs) and recombinant UGTs. Glucuronides of tectorigenin and irigenin were identified using high-performance liquid chromatography (HPLC) coupled with mass spectrometry and quantified by HPLC using a response factor method. The results showed that tectorigenin and irigenin were modified by glucuronidation in HLMs. One metabolite of tectorigenin (M) and two metabolites of irigenin (M1 and M2) were detected. Chemical inhibition and recombinant enzyme experiments revealed that several enzymes could catalyze tectorigenin and irigenin glucuronidation. Among them, UGT1A1 and UGT1A9 were the primary enzymes for both tectorigenin and irigenin; however, the former mostly produced irigenin glucuronide M1, while the latter mostly produced irigenin glucuronide M2. These findings suggest that UGT1A1 and UGT1A9 were the primary isoforms metabolizing tectorigenin and irigenin in HLMs, which could be involved in drug–drug interactions and, therefore, should be monitored in clinical practice.

Integrin-α9β1 as a Novel Therapeutic Target for Refractory Diseases: Recent Progress and Insights

Integrins refer to heterodimers consisting of subunits α and β. They serve as receptors on cell membranes and interact with extracellular ligands to mediate intracellular molecular signals. One of the least-studied members of the integrin family is integrin-α9β1, which is widely distributed in various human tissues and organs. Integrin-α9β1 regulates the physiological state of cells through a variety of complex signaling pathways to participate in the specific pathological processes of some intractable diseases. In recent years, an increasing amount of research has focused on the role of α9β1 in the molecular mechanisms of different refractory diseases and its promising potential as a therapeutic target. Accordingly, this review introduces and summarizes recent research related to integrin-α9β1, describes the synergistic functions of α9β1 and its corresponding ligands in cancer, autoimmune diseases, nerve injury and thrombosis and, more importantly, highlights the potential of α9β1 as a distinctive target for the treatment of these intractable diseases.

Flourensia fiebrigii S.F. blake: A medicinal plant from the Argentinean highlands with potential use as anti-rheumatic and anti-inflammatory

ETHNOPHARMACOLOGICAL RELEVANCE

Flourensia fiebrigii is a plant used in traditional medicine in the Argentine Calchaquí Valley as purgative, expectorant, anti-rheumatic and anti-inflammatory.

AIM OF THE STUDY

The aim of this study was to analyze the macroscopic and microscopic characteristics of F. fiebrigii leaf and stem, the phytochemical composition of leaves ethanolic extracts and to validate its traditional use as anti-rheumatic and anti-inflammatory.

MATERIALS AND METHODS

The macroscopic and microscopic description of F. fiebrigii leaf and stem was carried out. Two extracts (immersions and tinctures) from leaves were obtained. The phytochemical analysis and UHPLC-OT-MS metabolome fingerprinting of both extracts were performed. The anti-rheumatic and anti-inflammatory activities of both extracts were determined using enzymatic inhibition assays of xanthine-oxidase (XOD), secretory phospholipase A2 (sPLA2) and lipoxygenase (LOX).

RESULTS

The macroscopic and micrographic characters of F. fiebrigii were described to allow the botanical characterization of the plant species. The leaves extracts showed a high level of phenolic compounds with similar chromatographic patterns. Forty-five compounds were identified based on UHPLC-OT-MS including several sesquiterpenes, chalcones, flavonoids, isoflavonoids, a lignan and phenylpropanoids phenolic acids that have been identified for the first time in this plant species. F. fiebrigii extracts were able to inhibit the XOD activity and, consequently, the formation of uric acid and reactive oxygen species, primary cause of diseases, such as gouty arthritis (IC₅₀ values of 1.10-2.12 μg/mL). Pro-inflammatory enzymes like sPLA2 and LOX were also inhibited by F. fiebrigii extracts (IC₅₀ values of 22.00-2.20 μg/mL) decreasing the production of inflammation mediators.

CONCLUSIONS

The present work validates the traditional medicinal use of F. fiebrigii as anti-rheumatic and anti-inflammatory through the use of enzymatic assays. The presence of several chemical compounds with demonstrated anti-rheumatic and anti-inflammatory properties also supports the bioactivity of the F. fiebrigii.

Lung cancer cell-derived EDA-containing fibronectin induces an inflammatory response from monocytes and promotes metastatic tumor microenvironment

Tumor-associated macrophages (TAMs) play a pivotal role in facilitating tumor growth and metastasis. This tumor-promoting propensity of TAMs sets in as a result of their complex cross-talk with tumor cells mediated primarily by tumor cell-secreted proteins in the tumor microenvironment. To explore such interactions, we employed an immunoscreening approach involving the immunization of Balb-c mice with model human lung carcinoma cell line, A549. From serological examination combined with mass spectrometric analysis, EDA-containing fibronectin (EDA_FN ) was identified as a conspicuous immunogenic protein in A549 cell secretome. We showed that A549 secreted EDA_FN engages TLR-4 on THP-1 monocytes to drive the proinflammatory response via NF-κB signaling cascade. Conversely, A549 derived EDA_FN potentiates their metastatic capacity by inducing epithelial-mesenchymal transition through its autocrine activity. In conclusion, the study proposes a possible mechanism of cellular cross-talk between lung cancer cells and associated monocytes mediated by lung cancer-derived EDA_FN and resulting in the establishment of proinflammatory and metastatic tumor microenvironment.

FN-EDA mediates angiogenesis of hepatic fibrosis via integrin-VEGFR2 in a CD63 synergetic manner

Pathological angiogenesis is an important component of hepatic fibrosis along with fibrous deposition, but its role is not well understood. Here, we demonstrated that fibronectin containing extra domain A(FN-EDA), a fibronectin splice variant highly expressed in hepatic fibrosis, mediated angiogenesis in disease progression. FN-EDA was positively correlated with pathological angiogenesis in hepatic fibrosis, and a reduction in FN-EDA expression was associated with diminished intrahepatic angiogenesis and fibrosis. FN-EDA mostly colocalized with hepatic stellate cells (HSCs) and interference or blockage of FN-EDA attenuated migration and tube formation in co-cultured endothelial cells. Mechanistic studies indicated that FN-EDA was secreted to promote phosphorylation of VEGFR2 with the assistance of integrin and CD63. Targeting FN-EDA-integrin combination postponed the progression of hepatic angiogenesis and fibrosis in vivo. These results indicated that FN-EDA plays an emerging role in angiogenesis in hepatic fibrosis and could be a potential therapeutic intervention for the disease.

Scaffold stiffness influences breast cancer cell invasion via EGFR-linked Mena upregulation and matrix remodeling

Clinically, increased breast tumor stiffness is associated with metastasis and poorer outcomes. Yet, in vitro studies of tumor cells in 3D scaffolds have found decreased invasion in stiffer environments. To resolve this apparent contradiction, MDA-MB-231 breast tumor spheroids were embedded in 'low' (2 kPa) and 'high' (12 kPa) stiffness 3D hydrogels comprised of methacrylated gelatin/collagen I, a material that allows for physiologically-relevant changes in stiffness while matrix density is held constant. Cells in high stiffness materials exhibited delayed invasion, but more abundant actin-enriched protrusions, compared to those in low stiffness. We find that cells in high stiffness had increased expression of Mena, an invadopodia protein associated with metastasis in breast cancer, as a result of EGFR and PLCγ1 activation. As invadopodia promote invasion through matrix remodeling, we examined matrix organization and determined that spheroids in high stiffness displayed a large fibronectin halo. Interestingly, this halo did not result from increased fibronectin production, but rather from Mena/α5 integrin dependent organization. In high stiffness environments, FN1 knockout inhibited invasion while addition of exogenous cellular fibronectin lessened the invasion delay. Analysis of fibronectin isoforms demonstrated that EDA-fibronectin promoted invasion and that clinical invasive breast cancer specimens displayed elevated EDA-fibronectin. Combined, our data support a mechanism by which breast cancer cells respond to stiffness and render the environment conducive to invasion. More broadly, these findings provide important insight on the roles of matrix stiffness, composition, and organization in promoting tumor invasion.

Extra domain A-containing fibronectin expression in Spin90-deficient fibroblasts mediates cancer-stroma interaction and promotes breast cancer progression

Cancer-associated fibroblasts (CAFs) in the tumor microenvironment play major roles in supporting cancer progression. A previous report showed that SPIN90 downregulation is correlated with CAF activation and that SPIN90-deficient CAFs promote breast cancer progression. However, the mechanisms that mediate cancer-stroma interaction and how such interactions regulate cancer progression are not well understood. Here, we show that extra domain A (EDA)-containing fibronectin (FN), FN(+)EDA, produced by mouse embryonic fibroblasts (MEFs) derived from Spin90-knockout (KO) mice increases their own myofibroblast differentiation, which facilitates breast cancer progression. Increased FN(+)EDA in Spin90-KO MEFs promoted fibril formation in the extracellular matrix (ECM) and specifically interacted with integrin α4β1 as the mediating receptor. Moreover, FN(+)EDA expression by Spin90-KO MEFs increased proliferation, migration, and invasion of breast cancer cells. Irigenin, a specific inhibitor of the interaction between integrin α4β1 and FN(+)EDA, significantly blocked the effects of FN(+)EDA, such as fibril formation by Spin90-KO MEFs and proliferation, migration, and invasion of breast cancer cells. In orthotopic breast cancer mouse models, irigenin injection remarkably reduced tumor growth and lung metastases. It was supported by that FN(+)EDA in assembled fibrils was accumulated in cancer stroma of human breast cancer patients in which SPIN90 expression was downregulated. Our data suggest that SPIN90 downregulation increases FN(+)EDA and promotes ECM stiffening in breast cancer stroma through an assembly of long FN(+)EDA-rich fibrils; moreover, engagement of the Integrin α4β1 receptor facilitates breast cancer progression. Inhibitory effects of irigenin on tumor growth and metastasis suggest the potential of this agent as an anticancer therapeutic.

Atomic insight into prion disorder: An intricate detail gained by 0.5 μs molecular dynamics simulation of preventive G127V and deleterious D178V mutation in prion protein

In this study we are looking into two contradicting mutations found in prion protein (PrP) viz G127V and D178V, that are reportedly protective and pathogenic, respectively. Despite significant advances in comprehension of the role of pathogenic mutations, the role of protective mutation in amyloid fold inhibition still lacks a substantial basis. To understand the structural basis of protective mutation, molecular dynamics simulation coupled with protein-protein docking and molecular mechanics/Poisson-Boltzmann surface area analysis was used to understand the instant structural variability brought about by these mutations alone and in combination on PrP and prion-prion complex. Atomic-scale investigations successfully revealed that the binding pattern of prion-prion varies differentially in protective and pathogenic mutations with secondary structure showing distinct contrasting patterns, which could supposedly be a critical factor for differential prion behavior in protective and pathogenic mutations. Considering the reported role of an amyloid fold in prion-prion binding, the contrasting pattern has given us a lead in comprehending the role of these mutations and has been used in this study to look for small molecules that can inhibit amyloid fold for prion-prion interaction in pathogenic mutant carrying PrP.

Farrerol overcomes the invasiveness of lung squamous cell carcinoma cells by regulating the expression of inducers of epithelial mesenchymal transition

In recent years Epithelial Mesenchymal Transition (EMT) has been proposed as a mechanism indispensable to acquisition of metastatic properties by tumor cells. In this study we tested the ability of Farrerol, a Chinese herb-derived compound to ablate the EMT in human lung squamous cell carcinoma cells. Human lung squamous cell carcinoma cells, Calu-1 were treated with various concentrations of Farrerol for 24 h to examine its effect on their viability by the MTT assay. Only those concentrations which showed least effect on the viability of Calu-1 cells were further used to evaluate the expression of epithelial and mesenchymal markers by western blotting. Furthermore the effect of such concentrations on the migration and invasion of Calu-1 cells was determined by wound healing and transwell invasion assays respectively. The results demonstrated that Farrerol treatment led to the downregulation of Slug and Zeb-1, transcriptional regulators of EMT with the concomitant increase and decrease in the expression of E-cadherin and vimentin respectively. These data were further supported by migration and invasion assays which demonstrated that Farrerol treatment caused inhibited the migration and invasion of Calu-1 lung squamous cell carcinoma cells. Taken together, our results indicate that Farrerol suppresses lung squamous cell carcinoma cell metastatic potential by modulating the expression of EMT proteins.

Inhibition of the Ras/Raf/extracellular signal-regulated kinase 1/2 signaling pathway by compounds of natural origin for possible treatment of spinal cord injury: An in silico approach

Spinal cord injury (SCI) is a severe disease associated with permanent neurological deficit. Recent studies in the treatment of SCI have demonstrated that the Ras/Raf/extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway serves an important role in the disease etiology, and that upregulation of this signaling pathway is associated with the development of SCI. In the present study, inhibition of Ras protein was employed in order to downregulate the Ras/Raf/ERK1/2 signaling pathway using compounds of natural origin from the Interbioscreen natural compound database. To the best of our knowledge, this is the first study using a chemical-computational approach in order to identify novel small molecule inhibitors for Ras. A database of ~50,000 compounds was selected for virtual screening, setting a free energy binding bias of −7 kcal/mol to limit the number of compounds. The subset of compounds generated by virtual screening was further limited by subjecting these to the Lipinski's rule of five parameters. A total of five shortlisted compounds were subjected to molecular docking simulation. The compounds were docked into the GTP binding site of Ras, and the inhibition of this site was examined as a promising strategy for the downregulation of Ras/Raf/ERK1/2 signaling pathway. The compounds bound to the GTP binding site through hydrogen bonds and hydrophobic interactions. The identified lead compound was then subjected to molecular dynamics simulation, and the results revealed that GLY60 in the GTP binding site of Ras protein was the optimal binding site during a 100 nsec run.

Irigenin sensitizes TRAIL-induced apoptosis via enhancing pro-apoptotic molecules in gastric cancer cells

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) holds promising value for cancer therapy due to its capacity to induce apoptosis in cancer cells. Nevertheless, TRAIL therapy is greatly hampered by its resistance. Irigenin (Iri), isoflavonoids, can be isolated from the rhizome of Belamcanda chinensis, and has been shown anti-cancer properties. In this study, we explored if Iri could enhance TRAIL-regulated apoptosis in TRAIL resistant gastric cancer cells. Iri significantly potentiated TRAIL-triggered cytotoxicity. Iri alone and TRAIL alone showed no effective role in apoptosis induction, whereas combined treatment with Iri and TRAIL markedly induced apoptosis in cancer cells, as evidenced by the up-regulation of cleaved Caspase-8/-9/-3 and PARP. Additionally, the sensitization to TRAIL was along with the enhancement of pro-apoptotic proteins, including FAS-associated protein with death domain (FADD), death receptor 5 (DR5) and Bax. And suppressing FADD, DR5 and Bax by si RNA significantly reduced the apoptosis and enhanced the cell viability induced by the co-application of Iri and TRAIL. Moreover, the sensitization to TRAIL was accompanied by the decrease of Cellular-FLICE inhibitory protein (c-FLIP), Bcl-2 and Survivin. Additionally, Iri could sensitize TRAIL to produce reactive oxygen species (ROS). Pre-treatment of N-acetyl-cysteine (NAC), ROS scavenger, attenuated Iri plus TRAIL-induced apoptosis and improved cell viability. Finally, combination of Iri and TRAIL inhibited tumor growth in the xenograft model. Collectively, our present study gave new insights into the effects of Iri on potentiating TRAIL-sensitivity, and suggested that Iri could be a potential candidate for sensitizer of TRAIL-resistant cancer cell treatment.

Ferrerol overcomes the invasiveness of lung squamous cell carcinoma cells by regulating the expression of inducers of Epithelial Mesenchymal Transition

In recent years Epithelial Mesenchymal Transition (EMT) has been proposed as a mechanism indispensable to acquisition of metastatic properties by tumor cells. In this study we tested the ability of Ferrerol, a Chinese herb-derived compound to ablate the EMT in human lung squamous cell carcinoma cells. Human lung squamous cell carcinoma cells, Calu-1 were treated with various concentrations of Ferrerol for 24 h to examine its effect on their viability by the MTT assay. Only those concentrations which showed least effect on the viability of Calu-1 cells were further used to evaluate the expression of epithelial and mesenchymal markers by western blotting. Furthermore the effect of such concentrations on the migration and invasion of Calu-1 cells was determined by wound healing and transwell invasion assays respectively. The results demonstrated that Ferrerol treatment led to the downregulation of Slug and Zeb-1, transcriptional regulators of EMT with the concomitant increase and decrease in the expression of E-cadherin and vimentin respectively. These data were further supported by migration and invasion assays which demonstrated that Ferrerol treatment caused inhibited the migration and invasion of Calu-1 lung squamous cell carcinoma cells. Taken together, our results indicate that Ferrerol suppresses lung squamous cell carcinoma cell metastatic potential by modulating the expression of EMT proteins.

Fibronectin promotes directional persistence in fibroblast migration through interactions with both its cell-binding and heparin-binding domains

The precise mechanisms through which insoluble, cell-adhesive ligands induce and regulate directional cell migration remain obscure. We recently demonstrated that elevated surface density of physically adsorbed plasma fibronectin (FN) promotes high directional persistence in fibroblast migration. While cell-FN association through integrins α₅β₁ and α_vβ₃ was necessary, substrates that selectively engaged these integrins did not support the phenotype. We here show that high directional persistence necessitates a combination of the cell-binding and C-terminal heparin-binding domains of FN, but does not require the engagement of syndecan-4 or integrin α₄β₁. FN treatment with various fixation agents indicated that associated changes in fibroblast motility were due to biochemical changes, rather than alterations in its physical state. The nature of the coating determined the ability of fibroblasts to assemble endogenous or exogenous FN, while FN fibrillogenesis played a minor, but significant, role in regulating directionality. Interestingly, knockdown of cellular FN abolished cell motility altogether, demonstrating a requirement for intracellular processes in enabling fibroblast migration on FN. Lastly, kinase inhibition experiments revealed that regulation of cell speed and directional persistence are decoupled. Hence, we have identified factors that render full-length FN a promoter of directional migration and discuss the possible, relevant mechanisms.