Promotive role of MBNL3 and PXN genes expressions with lncRNA PXN-AS1-L on gastric cancer.

This study presents a novel approach targeting CD155, an overexpressed protein in lung adenocarcinoma (LUAD), using nanobodies with exceptional precision and efficacy. The significant upregulation of CD155 in LUAD, associated with poor patient outcomes, highlights its potential as a therapeutic target. An anti-CD155 nanobody (A5 Nb) is developed that binds to CD155-positive lung cancer cells with high affinity (A5 Nb Kd = 0.23 nM). The complementarity-determining region of A5 Nb forms hydrophobic interactions and hydrogen bonds with CD155, promoting selective binding and stabilization of A5 Nb-CD155 complex. This interaction inhibits focal adhesion signaling by downregulating paxillin (PXN), leading to a >50% reduction in cell migration. Additionally, A5 Nb conjugated to liposomes loaded with doxorubicin (A5-LNP-DOX) demonstrates a 2- to 3-fold increase in uptake and cytotoxicity in CD155-positive A549 cells, suggesting its potential as a targeted drug delivery system. Therapeutic efficacy was further validated in both lung orthotopic mouse models and lung cancer organoid xenografts, where A5-LNP-DOX exhibited robust antitumor effects and selective targeting. The CD155-PXN axis emerges as a clinically relevant target, correlating with poor outcomes in patients with lung cancer. This study highlights the therapeutic potential of A5 nanobodies in targeting CD155-overexpressing lung cancer cells and offers insights for future developments in lung cancer therapeutics.

Background Diabetic retinopathy (DR), a leading cause of vision loss, arises from chronic inflammation, vascular injury, and immune dysregulation. Aging-related mechanisms, including inflammaging, further exacerbate immune activation. The renin–angiotensin-aldosterone system (RAS) has been implicated in vascular dysfunction and chronic inflammation in DR. Paxillin (PXN), a cytoskeletal adaptor regulating immune cell migration, has not been fully explored in the context of DR and aging-related immune responses. Objective To determine how PXN + monocytes contribute to DR progression, with a focus on SELPLG-SELL-mediated chemotaxis, PXN-RAS interactions, and age-related inflammatory remodeling. Methods Mendelian randomization (MR) and single-cell transcriptomics identified PXN as a putative driver of DR. Functional assays were performed in RAW264.7 macrophages with PXN overexpression or knockdown under high-glucose conditions, with or without Losartan treatment. qPCR, CCK-8, ELISA, flow cytometry, and immunoblotting were used to assess inflammatory and oxidative pathways. Results MR revealed a causal association between PXN and DR risk, highlighting the SELPLG-SELL axis as a major chemotaxis pathway. Single-cell RNA-seq showed PXN + monocytes amplify T/NK cell crosstalk and immune infiltration. PXN overexpression promoted M1 polarization, upregulated SELL/SELPLG, increased IL-6, IL-17, and IL-23 secretion, and enhanced ACE-driven oxidative stress, attenuating Losartan's anti-inflammatory effects. These findings link PXN + monocytes to inflammaging-like immune remodeling in DR. Conclusions PXN amplifies pro-inflammatory chemotaxis and immune aging in DR, undermining RAS inhibition. Targeting PXN may mitigate inflammaging-driven retinal inflammation and improve therapeutic responses in diabetic retinopathy.

Paxillin (PXN) and focal adhesion kinase (FAK) are two major components of the focal adhesion complex, a multiprotein structure linking the intracellular cytoskeleton to the cell exterior. The interaction between the disordered amino-terminal domain of PXN and the carboxyl-terminal targeting domain of FAK (FAT) is necessary and sufficient for localizing FAK to focal adhesions. Furthermore, PXN serves as a platform for recruiting other proteins that together control the dynamic changes needed for cell migration and survival. Here, we show that the PXN N-domain undergoes significant compaction upon FAT binding, forming a 48-kilodalton multimodal complex with four major interconverting states. Although the complex is flexible, each state has unique sets of contacts involving disordered regions that are both highly represented in ensembles and conserved. PXN being a hub protein, the results provide a structural basis for understanding how shifts in the multistate equilibrium (e.g., through ligand binding and phosphorylation) may rewire cellular networks leading to phenotypic changes.

The T-box transcription factor TBX1 is expressed in the cardio-pharyngeal mesoderm. The correct cell fate decisions of cardio-pharyngeal mesoderm cells are critical, as any defect in this process can alter second heart field morphogenesis and lead to cardiac outflow tract and pharyngeal apparatus defects. The second heart field plays a crucial role in cardiac development by incorporating cardiac progenitors into the heart. It is also the major gene implicated in 22q11.2 deletion (or DiGeorge) syndrome, a primary genetic cause of congenital heart defects associated with hypoplasia of the cardiac outflow tract. The murine model recapitulates the heart phenotype and shows anomalies in the ECM-integrin-focal adhesion pathway. Here, we used a cell culture model to manipulate Tbx1 levels in order to molecularly and functionally characterize the defective focal adhesions (FAs) caused by Tbx1 loss and to analyse their dynamics on the ECM. Intriguingly, we found that Tbx1 regulates FA dynamics by influencing the FA disassembly process. Furthermore, Tbx1 is required for the paxillin (PXN) signalling pathway and controls cell spreading primarily through Pxn regulation. In fact, consistent with this observation, the ectopic expression of PXN rescued the cell spreading and signalling defects caused by Tbx1 depletion. Finally, our study revealed that, at least in vitro, TBX1 is a critical regulator of cell adhesion by affecting FA turnover.

Paxillin (PXN) and focal adhesion kinase (FAK) are two major components of the focal adhesion complex, a multiprotein structure linking the intracellular cytoskeleton to the cell exterior. The interaction between the disordered N-terminal domain of PXN and the C-terminal targeting domain of FAK (FAT) is necessary and sufficient for localizing FAK to focal adhesions. Furthermore, PXN serves as a platform for recruiting other proteins that together control the dynamic changes needed for cell migration and survival. Here, we show that the PXN N-domain undergoes significant compaction upon FAT binding, forming a 48-kDa multi-modal complex with four major interconverting states. Although the complex is flexible, each state has unique sets of contacts involving disordered regions that are both highly represented in ensembles and conserved. PXN being a hub protein, the results provide a structural basis for understanding how shifts in the multi-state equilibrium (e.g. through ligand binding and phosphorylation) may rewire cellular networks leading to phenotypic changes.

Abstract Background: The molecular mechanisms in which angiopoietin-like 4 (ANGPTL4), a pluripotent protein implicated in cancer development, contribute to head and neck squamous cell carcinoma (HNSCC) growth and dissemination are unclear. Methods: We analyzed ANGPTL4 expression in human normal oral keratinocytes (NOKs), dysplastic oral keratinocytes (DOKs), oral leukoplakia cells (LEUK1), and HNSCC cell lines, HN13, HN6, HN4, HN12, and CAL27, as well as in tissue biopsies from patients with oral dysplasia, and primary and metastatic HNSCC. We further examined the contribution of ANGPTL4 cancer progression in an HNSCC orthotopic floor-of-mouth tumors model and upstream and downstream signaling pathways linking ANGPTL4 to cancer cell proliferation and migration. Results: ANGPTL4 expression was upregulated in premalignant DOKs and HNSCC cell lines compared to NOKs as well as in tissue biopsies from patients with oral dysplasia, and primary and metastatic HNSCC. Downregulation of ANGPTL4 expression inhibited primary and metastatic cancer growth in an HNSCC orthotopic tumor model. Interestingly, ANGPTL4 binding to the neuropilin 1 (NRP1) receptor led to phosphorylation of the focal adhesion protein, paxillin (PXN), and tumor cell migration; this was dependent on the tyrosine kinase ABL1. Further, we examined theextracellular signaling associated with ANGPTL4 expression in HNSCC. Intriguingly, amphiregulin (AREG), an epidermal growth factor receptor ligand, induced ANGPTL4 expression in NOKs and DOKs. AREG-induced activation of cell proliferation was dependent on ANGPTL4. We show that the proliferative potential of AREG in HNSCC is, in part, mediated by ANGPTL4. We also observed a role for p38 MAPK as an important downstream effector for the pro-tumorigenic effects ofANGPTL4 and an upregulation of a wide array of proliferative, proangiogenic, and proinflammatory factors upon treatment of NOKs with this adipokine. This suggests that ANGPTL4 may induce HNSCC tumorigenesis through both autocrine and paracrine pathways. Conclusion: Our findings identify novel opportunities for the development of therapies targeting the ANGPTL4-induced signaling pathways for the treatment of patients with HNSCC. Citation Format: Ajay Kumar. Angiopoietin-like 4 induces proliferation and migration of head and neck squamous cell carcinoma cells via p38 kinase and NRP1/ABL1/PXN pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 194.

PurposeVascular dementia (VaD) is the second most common dementia in the world. An increasing number of studies have demonstrated the important role of long non-coding RNAs (lncRNAs) in VaD. Our previous investigation demonstrated that Trimethylamine-N-oxide (TMAO) exacerbates cognitive impairment and neuropathological alterations in VaD rats. Thus, we hypothesized that TMAO could play an injury role in VaD by regulating lncRNAs.Materials and MethodsThe rats using the bilateral common carotid artery (2VO) model were administered TMAO (120 mg/kg) for 8 consecutive weeks, 4 weeks preoperatively and 4 weeks postoperatively. High-throughput sequencing was conducted to investigate the effects of TMAO treatment on lncRNA expression in rat hippocampus and bioinformatics analysis was performed to identify potential downstream targets. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the levels of lncRNA fetal-lethal noncoding developmental regulatory RNA (Fendrr), miR-145-5p, and paxillin (PXN). Learning and spatial memory capacities were measured, as well as inflammatory factors. Nissl staining was used to observe neuronal injury in the CA1 area of the hippocampus. Furthermore, we used the Fendrr loss-of-function assay, miR-145-5p gain-of-function assays and PXN loss-of-function assay to explore the mechanisms by which TMAO acts on VaD.ResultsTMAO administration upregulated lncRNA Fendrr expression in the rat hippocampus, while the damaging effects of TMAO were counteracted after knockdown of Fendrr. Fendrr exhibits highly expressed in 2VO rats and sponged miR-145-5p, which targets PXN. Silencing of Fendrr or PXN, or promotion of miR-145-5p improved neurological function injury, reduced neuronal damage, as well as repressed inflammation response. Inhibition of miR-145-5p abrogated up Fendrr knockdown mediated influence on 2VO rats.ConclusionThe results of this study indicated that TMAO inhibits the miR-145-5p/PXN axis by increasing the Fendrr expression, thus exacerbating the development of VaD.

Abstract The mechanisms that regulate Ewing sarcoma (EWS) cell dissemination are poorly characterized. We have reported that though cell line studies show the EWSR1::FLI1/ERG fusion oncoproteins represses ETS1 expression, there is inter-tumoral variations in its mRNA levels and higher expression of ETS1 in tumors correlate with reduced overall patient survival. ETS1 encodes a transcription factor that regulates the movement of several early progenitor cell sub-types, and activation of ETS1 in EWS cells enhanced their movement and migration. This suggests that ETS1 expression could promote cell dissemination. We also showed that ETS1 expression in EWS cells upregulated the expression of the focal adhesion (FA) protein TENSIN3 (TNS3). Critically, depletion of TNS3 reverted the enhanced formation of FAs induced by ETS1 and partially rescued the increased migratory phenotype. In this study, we investigated the ETS1-induced changes in the phenotype of EWS cells by assessing TNS3 function in the context of other FA proteins. We generated epigenetic and transcriptomic profiles of EWS cells using ChIP-seq, CUT&RUN-seq, or RNA-seq in unperturbed, siRNA-treated or CRISPRa-EWS cells. We used dCas9-VP64 (control) or ETS1-activated (ETS1a) SK-N-MC cells and performed immunofluorescence and super resolution microscopy employing antibodies against TNS3, vinculin (VCL), paxillin (PXN), pan-talin (TLN), and focal adhesion kinase (FAK). Previously, we observed TNS3 and the FA scaffold protein VCL at the membrane projections of ETS1a EWS cells, however, we did not determine whether this reflected a change in VCL expression and/or protein redistribution. Epigenetic analyses showed EWSR1::FLI1/ERG, and ETS1 binding (following depletion of EWSR1::FLI1) at VCL and its expression increased 6- and 3-fold following EWSR1::FLI1 and EWSR1::ERG depletion, respectively. In contrast, we observed only a slight increase in VCL expression (RNA or protein) in ETS1a EWS cells. This suggests that our visualization of VCL in the ETS1a EWS cells reflected a change in its localization, not expression. Consistent with this finding, in the ETS1a EWS cells, we observed an increase in VCL’s non-nuclear intensity relative to control cells. This observation reflected VCL’s recruitment to the plasma membrane, a phenotype that TNS3-depletion reversed. To further study whether TNS3 is the predominate determinant of FA formation in ETS1a EWS cells, we examined other FA components, specifically PAX, TLN1, TLN2, and FAK. We observed no evidence of EWSR1::FLI1/ERG or ETS1 directly regulating these genes. Nevertheless, PXN, TLN, and FAK, all showed an increase in both total and non-nuclear intensities following ETS1 activation, suggesting that ETS1 indirectly activates the expression of other FA proteins. Nevertheless, depletion of TNS3 decreased the non-nuclear intensities of these FA proteins, confirming the importance of TNS3 in the formation FAs in the ETS1-modfied lines. We thus conclude that if expressed in an EWS cell, ETS1’s regulation of TNS3 that will enhance FA formation and cell movement. Citation Format: Vernon J. Ebegboni, Tamara J. Jones, Shaoli Das, Erica C. Pehrsson, Soumya Sundara Rajan, Natasha J. Caplen. The ETS1-driven expression of TNS3 in Ewing sarcoma cells enhances the formation of the focal adhesions that promote cell movement [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pediatric Cancer Research; 2024 Sep 5-8; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl):Abstract nr A004.

Novel biomarkers associated with oxidative stress and immune infiltration in intervertebral disc degeneration based on bioinformatics approaches

Paxillin (PXN) is one of the proteins involved in cell adhesion. PXN and integrins constitute a key site for the focal adhesion between the cell and extracellular matrix. Several studies have shown that PXN is a factor in tumor formation, progression, invasion, and metastasis. This study evaluated PXN expression in four types of odontogenic lesions with different aggressive behaviors. In this retrospective cross-sectional study, PXN expression was immunohistochemically assessed in 68 paraffin-embedded tissue samples from patients with the confirmed diagnosis of four types of odontogenic lesions, including 14 dentigerous cysts (DC), 20 odontogenic keratocyst (OKC), 16 unicystic ameloblastoma, and 18 solid ameloblastoma. The PXN expression in these samples were scored based on the percentage and intensity of immunoreactivity, and compared among the groups by Chi-square test. The PXN marker was detected in the cytoplasm of tumor cells (unicystic and solid ameloblastoma) and the epithelial layer of cysts (DC and OKC). The intensively stained marker of PXN was observed in 9 cases (64.3%) of the DC, 14 cases (70%) of OKC, 12 cases (75%) of unicystic ameloblastoma, and 13 cases (72.2%) of solid ameloblastoma. However, there was not statistical difference of PXN protein expression between DC and OKC (p Value = 0.51) and unicystic and solid ameloblastoma (p = 0.58), also the same was true for cysts and tumors (p = 0.37). The expression of PXN is not related to the biological behaviors of odontogenic lesions.

Abstract Hypoxia is a physiologically relevant feature of the prostate microenvironment that promotes migration and invasion resulting in extracapsular extension, the first step toward metastatic progression. Prostate cancer invasion depends on integrins as mechanosensing membrane receptors during creation of membrane lamellipodial protrusions and focal adhesions (FAs). The objective of this study was to determine the molecular events that promote membrane protrusions under hypoxia and whether this was dependent upon kindlin-2, an essential integrin adapter that marks activated β1 integrin heterodimers. DU145 cells depleted of one copy of FERMT2+/- (50% kindlin-2 expression) by CRISPR/Cas9 or DU145 FERMT2wt (normal kindlin-2 expression) were grown under acute exposure to hypoxia (1% O2) and compared to cells grown under normal tissue culture conditions. Immunofluorescence microscopy experiments were performed to analyze the spatial temporal expression of kindlin-2 complexes. Kindlin-2 complexes were confirmed by immunoprecipitation using an anti-kindlin-2 3A3-antibody from Sigma-Aldrich. Colocalization was determined by obtaining 2D immunofluorescence microscopy images analyzed using ImageJ 2.1.0/1.53c and Nikon NIS-Elements 5.30.04. Under hypoxic conditions, analysis over four time points (4h, 8h, 12h & 16h) increased the number and area of FAs (marked by paxillin (PXN)) containing kindlin-2 in a time-dependent manner by 2-fold and 1.5-fold, respectively, but not in DU145 FERMT2+/- cells. Additionally, hypoxia increased membrane area, perimeter, and the plasma membrane intensity of kindlin-2 exclusive of FAs in DU145 FERMT2wt cells which was maximal after 8 hours of hypoxia. Interestingly, limiting the kindlin-2 expression in FERMT2+/- cells resulted in a loss of hypoxia-induced lamellipodial protrusions (marked by lamellipodin (RAPH1)) containing kindlin-2 while hypoxia-induced kindlin-2 FA changes were preserved. The current working hypothesis is that lamellipodial protrusions are dependent upon kindlin-2 expression whereas the established FAs are stable under conditions of reduced kindlin-2 expression in hypoxia. This data suggests that an early stage of migration, lamellipodial extensions are sensitive to kindlin-2 availability. Further studies are required to determine the dynamic interplay between protrusive events and focal adhesions in relation to kindlin-2 for prostate cancer cells to migrate and invade. Citation Format: Colin Nelson, Daniel Hernandez-Cortes, Kendra D. Marr, Jaime MC Gard, Allan I. Paxson, William L. Harryman, Natalya K. Seppanen, John M. Ryniawec, Anne E. Cress. Lamellipodial protrusions induced by hypoxia depend upon kindlin-2 in prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5418.

Role of steroid hormones in the maintenance of focal adhesions in bovine oviductal epithelial cells

Colorectal cancer (CRC) is the third most common cancer worldwide, and metastasis is strongly associated with poor prognosis in patients with CRC. We have previously found that the expression and phosphorylation of paxillin (PXN) play an important role in the metastatic potential of breast cancer. This study examined the potential role of PXN in CRC metastasis. Resected tumor specimens from 92 patients with CRC were subjected to immunohistochemical analysis of PXN levels. Three human CRC cell lines, HCT116, LoVo, and SW480 were used for scratch and transwell invasion assays to examine the effects of PXN over-expression. RNA sequencing was performed to obtain the expression profiles under PXN over-expression. High levels of PXN were significantly correlated with advanced stage, higher carcinoembryonic antigen and carbohydrate antigen 19-9 levels, and poorer overall survival. The migration ability of CRC cells was enhanced by exogenous PXN over-expression, but this enhancement was not observed in cells harboring exogenously mutated PXN at Tyr31 or Tyr88 phosphorylation sites. In PXN-over-expressing cells, TNF-α signaling via NF-[Formula: see text]B was positively enriched. PXN expression and phosphorylation at Tyr31 or Tyr88 may influence the migration and invasion of CRC cells. PXN expression and phosphorylation at Tyr31 or Tyr88 are promising targets for evaluating prognosis and treating CRC.

Abstract Optimizing the dietary concentrations and ratios of branched-chain amino acids (BCAA) is necessary to optimize broiler chicken growth performance and carcass meat yield. A central composite design (CCD) study was conducted to understand the impact of dietary BCAA concentrations and ratios on Pectoralis major (PM) muscle protein expression involved in mTOR and related protein synthesis pathways as well as and investigate the mechanisms behind how BCAA ratios affect broiler growth and muscle protein accretion. A total of 2,592 d-old Ross 344 × 708 male broilers were randomly placed in 144 floor pens (n = 18 birds per pen). Before the initiation of the experimental finisher phase, all pens were standardized to contain 15 birds per pen. Each pen received 1 of 15 dietary treatments in the 23 CCD with 6 center points from 20 to 35 d of age, varying in digestible ratios of valine:lysine (Val:Lys; 64 to 87), leucine:lysine (Leu:Lys; 110 to 185), and isoleucine:lysine (Ile:Lys; 52 to 75). On d 35, 1 bird per pen was randomly selected for PM protein extraction and proteomic analysis via data independent acquisition protein sequencing with a timsTOF Pro 2 LC/MS/MS and Spectronaut 15 software. Ribosomal protein S6 kinase (RPS6KA3), eukaryotic elongation factor 2 (EEF2), eukaryotic translation initiation factor 4B (EIF4B), eukaryotic translation initiation factor 4E (EIF4E), CAP-Glycine domain containing linker protein 1 (CLIP1), mitogen-activated protein kinase 3 (MAPK3), Protein kinase domain-containing protein (MAP2K1), Dual-specificity mitogen-activated protein kinase kinase 2 (MAP2K2), paxillin (PXN), and regulator complex protein (LAMTOR3) were identified, quantified, and analyzed as a CCD using the RSREG procedure of SAS ver. 9.4 with significance set at P ≤ 0.10. The surface response models for RPS6KA3, EEF2, EIF4B, EIF4E, MAPK3, MAP2K1, MAP2K2, CLIP1, PXN, and LAMTOR3 were not significant (P ≥ 0.926; R2 values ≤ 0.1). No linear (P ≥ 0.5223), quadratic (P ≥ 0.0.634) or cross product (P ≥ 0.6238) regression effects were observed for any of the proteins analyzed. A minimum stationary point was observed for RPS6KA3, EEF2, MAPK3, and LAMTOR3. However, optimal values for the other proteins could not be obtained due to stationary saddle points. Overall, the results in this study indicate that varying concentrations of dietary BCAA may not impact expression of proteins related to broiler skeletal muscle growth on d 35 following the 15-d treatment period, despite the influence on live performance. This is a limitation of this study and suggests that if the mTOR pathway was involved it was not still differentially up- or down-regulated at this time point. Further investigation and new studies with multiple time points will be required to better understand the mechanisms behind how BCAA impact broiler growth and muscle development.

Angiopoietin-like 4 induces head and neck squamous cell carcinoma cell migration through the NRP1/ABL1/PXN pathway

ObjectiveTo investigate the expression, prognosis, and underlying mechanism of Paxillin (PXN) in ovarian cancer. Materials and methodsBy comprehensive use of various bioinformatics tools, we analyzed the expression of PXN and its prognostic value in ovarian cancer. Then, the enrichment analyses were conducted to determine the possible regulatory pathways PXN involved in ovarian cancer. Finally, the associations of PXN expression with immune cell infiltration and immune checkpoints were analyzed. ResultsPXN was highly expressed in ovarian cancer and its expression could independently predict the overall survival of ovarian cancer patients. More importantly, PXN had a superior ability in predicting long-term survival than age and tumor residual disease in ovarian cancer patients. In addition, PXN was positively related to adherens junction and tight junction pathways. Significant negative relationships between PXN expression and immune infiltrates were observed, however, PXN was positively connected with immune checkpoint (VSIR) in ovarian cancer. ConclusionsPXN serves as a reliable prognostic biomarker and may be a potent therapeutic target for ovarian cancer. Moreover, high PXN expression may affect ovarian cancer progression via positive regulation of metastasis-related pathways.

Purpose Programmed cell death factor 10 (PDCD10) is associated with intercellular junction, cytoskeleton organization, cell proliferation, apoptosis, exocytosis, and angiogenesis. However, the role of PDCD10 in human cancer is unclear. This study aims to explore the role of PDCD10 in various tumors and its possible mechanism through bioinformatics analysis. Methods We verified the expression of the PDCD10 gene based on data from the ONCOMINE, TIMER2.0, and TISDB databases. The correlation of PDCD10 with prognosis of patients with different tumors was analyzed using data from the GEPIA2 database. Proteins bound to PDCD10 were analyzed from the STRING database. PDCD10, PDCD10-binding proteins, and associated candidate genes were analyzed in DAVID for functional and pathway analyses. We also evaluated the immunological, clinical, and genetic aspects of distinct cancers by using TIMER2.0 and the connection between PDCD10 expression and tumor immune subtypes by using TISDB. Single-cell sequencing data from the CancerSEA database were used to characterize cancer cell functional states and generate heat maps. Results PDCD10 overexpression is linked to certain molecular subtypes of human cancer. Low PDCD10 expression in patients with bladder urothelial carcinoma (BLCA), lung adenocarcinoma (LUAD), liver hepatocellular carcinoma (LIHC), adrenocortical carcinoma (ACC), head and neck squamous cell carcinoma (HNSC), kidney chromophobe carcinoma (KICH), brain lower grade glioma (LGG), pancreatic adenocarcinoma (PAAD), uterine corpus endometrial carcinoma (UCEC), oral squamous cell carcinoma (OSCC), and esophageal adenocarcinoma (ESAD) was correlated with favorable OS, whereas high PDCD10 expression in patients with LUSC, KIRC, READ, SKCM, and THYM was correlated with good prognosis. STRING network prediction results showed that 20 proteins, namely, paxillin (PXN), CCM2 scaffold protein (CCM2), TRAF3 interacting protein 3 (TRAF3IP3), FGFR1 oncogene partner 2 (FGFR1OP2), chromosome 4 open reading frame 19 (C4orf19), suppressor of IKBKE 1 (SIKE1), serine/threonine kinase 25 (STK25), striatin (STRN), protein phosphatase 2 catalytic subunit alpha (PPP2CA), mammalian sterile-20-like kinase 4 (MST4), MOB family member 4 (MOB4), protein phosphatase 2 scaffold subunit Abeta (PPP2R1B), sarcolemma-associated protein (SLMAP), serine/threonine kinase 24 (STK24), striatin 4 (STRN4), STRN3, protein phosphatase 2 scaffold subunit A alpha (PPP2R1A), striatin interacting protein 1 (STRIP1), CTTNBP2 N-terminal like (CTTNBP2NL), and cortactin binding protein 2 (CTTNBP2), can bind to PDCD10. Gene enrichment analysis suggested that PDCD10 is involved in the occurrence of different tumors through the Hippo signalling pathway, RNA transport, mRNA monitoring pathway, endocytosis, and T cell receptor signalling pathway. An inverse relationship was found between PDCD10 expression and cancer-associated fibroblasts in LUSC and TGCT, and PDCD10 expression was strongly connected with immunological subtypes, such as C1 (wound healing), C2 (interferon-gamma dominant), C3 (inflammation), C4 (lymphocyte depletion), C5 (immune silenced), and C6 (TGF-beta dominant). Finally, analysis of single-cell sequencing data revealed that PDCD10 expression is linked to epigenetic reprogramming, DNA repair, cell cycle progression, cell differentiation, inflammation, cell proliferation, cell differentiation, cell invasion, and angiogenesis. Conclusion The results of our investigation demonstrate that PDCD10 has an oncogenic function in many cancer types. This study provides a reference for future research on antitumor therapeutic targets.

Abstract The laminin-binding integrins are mechanosensory receptors critical for cell adhesion and structural organization that link the extracellular matrix (ECM) to the cytoskeleton. Integrin α6β1 is associated with prostate cancer (PCa) migration, invasion, metastasis, and decreased cancer-specific survival. Kindlin-2 (FERMT2) is a β1 integrin adaptor and mechanosensory focal adhesion (FA) protein that activates and clusters integrins in response to structural ECM alterations in the tumor microenvironment. Our goal was to determine if integrin-kindlin-2 adhesion complexes (kindlin-2:α6β1) were responsive to hypoxia, a physiologically relevant and altered microenvironment in PCa progression. Five different endpoints were tested including the biochemical analysis of kindlin-2 complexes, qRT-PCR, immunoblotting, immunocytochemistry, and electric cell impedance sensing (ECIS). Using DU145 prostate cancer cells grown under hypoxia (1% O2) for up to 16 hours, the results showed a reversible increase in kindlin-2:α6β1 complexes with maximal assembly within 4 hours and disassembly starting by 8 hours. Notably, kindlin-2:α6β1 complexes were found exclusively within membrane projections and were not observed within hypoxia-inducible paxillin (PXN)-containing FAs. The hypoxia induced kindlin-2:α6β1 complexes and classical FAs were dependent on kindlin-2 as determined by CRISPR-Cas9 heterozygous deletion of FERMT2. Protein co-localization of α6 integrin and PXN with kindlin-2 within membrane projections and FAs, respectively, was also induced under hypoxia. Further, non-invasive ECIS measurements in live cells confirmed functional cell-cell and cell-ECM dynamics driven by hypoxia and requiring kindlin-2. Our results indicate that the kindlin-2:α6β1 complexes are uniquely associated with FA-independent membrane projections induced by hypoxia, a tumor microenvironment associated with aggressive prostate cancer. The novel kindlin-2:α6β1 complexes may represent an actionable pharmacological target for blocking escape of organ confined disease and metastasis promoting steps of human prostate cancer. (Partially supported by NIH grants CA P30 23074, DOD W81XWH-19-1-0455, and NCI R01 CA242226). Citation Format: Daniel Hernandez-Cortes, Jaime M.C. Gard, Beatrice S. Knudsen, Noel A. Warfel, Anne E. Cress. Kindlin-2 complexes containing α6β1 integrin are responsive to hypoxia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3835.

FAK (focal adhesin kinase), a tyrosine kinase, plays an imperative role in cell-cell communication, particularly in cell signaling systems. It is a multi-functional signaling protein, which integrates and transduces signals into cancer cells through growth factor receptors or integrin and its interaction with Paxillin (PAX). The molecular processes by which FAK promotes the development and progression of cancer have progressively established the possible relationship between FAK-PAX complex in many types of cancer. The interaction of FAX and PAX is very important in breast cancer and thus acts as an essential biomarker for drugs, vaccines or peptide inhibitor designing. In this regard, computational approaches, particularly peptide designing to target the binding interface of the interacting partners, would greatly assist the design of peptide inhibitors against various cancer. Accordingly, in this present study, we screened 236 experimentally validated anti-breast cancer peptides using computational drugs repositioning approach to design peptides targeting the FAK-PAX complex. Using protein-peptide docking the binding site for the HP1 was confirmed and a total of 236 anti-breast cancer peptides were screened. Among the 236, only 12 peptides reported a docking score better than the control. From these 12, Magainin with the docking score - 103.8 ± 10.3kcal/mol, NRC-07 with the docking score - 100.8 ± 16.5kcal/mol, and Indolicidin with the docking score - 101.7 ± 3.9kcal/mol, peptides potentially inhibit the FAX-PAX binding. Calculation of protein's motion and FEL revealed the binding and inhibitory behavior. Moreover, binding free energy (MM/GBSA) confirmed that Magainin exhibited the total binding energy - 53.28kcal/mol, NRC-07 possessed the TBE - 44.16kcal/mol, and Indolicidin reported the TBE of - 40.48kcal/mol, thus explaining the inhibitory potential of these peptides. In conclusion, these peptides exhibit strong inhibitory potential and could abrogate the FAK-PAX complex in in vitro models and thus may relieve the burden of breast cancer.