Integrin Alpha Subunits Research Articles

Corrigendum to: Downregulating integrin subunit alpha 7 (ITGA7) promotes proliferation, invasion, and migration of papillary thyroid carcinoma cells through regulating epithelial-to-mesenchymal transition

Corrigendum to: Downregulating integrin subunit alpha 7 (ITGA7) promotes proliferation, invasion, and migration of papillary thyroid carcinoma cells through regulating epithelial-to-mesenchymal transition

A New Strategy to Inhibit Scar Formation by Accelerating Normal Healing Using Silicate Bioactive Materials.

Inspired by the scar-free wound healing in infants, an anti-scar strategy is proposed by accelerating wound healing using silicate bioactive materials. Bioglass/alginate composite hydrogels are applied, which significantly inhibit scar formation in rabbit ear scar models. The underlining mechanisms include stimulation of Integrin Subunit Alpha 2 expression in dermal fibroblasts to accelerate wound healing, and induction of apoptosis of hypertrophic scar fibroblasts by directly stimulating the N-Acylsphingosine Amidohydrolase 2 expression in hypertrophic scar fibroblasts, and indirectly upregulating the secretion of Cathepsin K in dermal fibroblasts. Considering specific functions of the bioactive silicate materials, two scar treatment regimes are tested. For severe scars, a regenerative intervention is applied by surgical removal of the scar followed by the treatment with bioactive hydrogels to reduce the formation of scars by activating dermal fibroblasts. For mild scars, the bioactive dressing is applied on the formed scar and reduces scar by inducing scar fibroblasts apoptosis.

Galectin-8 Contributes to Human Trophoblast Cell Invasion.

Galectins are a class of lectins that are extensively expressed in all organisms. Galectins are involved in a range of functions, including early development, tissue regeneration, cancer and inflammation. It has been shown that galectin-8 is expressed in the villous and extravillous trophoblast (EVT) cells of the human placenta; however, its physiological role in pregnancy establishment has not been elucidated. Taking these factors into account, we investigated the functional role of galectin-8 in HTR-8/SVneo cells-a human EVT cell line-and human primary cytotrophoblast cells isolated from a first-trimester placenta. We analyzed the effects of recombinant human galectin-8 (rh galectin-8) on the adhesion, migration and invasion of HTR-8/SVneo cells. We used qPCR, cell-based ELISA (cELISA) and gelatin zymography to study the effects of galectin-8 on mediators of these processes, such as integrin subunits alpha-1 and beta-1 and matrix metalloproteinases (MMPs)-2 and -9, on the mRNA and protein levels. Further, we studied the effects of galectin-8 on primary cytotrophoblast cells' invasion. Galectin-8 stimulated the adhesion, migration and invasion of HTR-8/SVneo cells, as well as the invasion of primary cytotrophoblasts. In addition, the MMP-2 and -9 levels were increased, while the expression of integrins alpha-1 and beta-1 was not affected. Galectin-8 has the ability to positively affect EVTs' invasion, so it can be considered a significant factor in the trophoblast cell invasion process.

Prediction of Future Parkinson Disease Using Plasma Proteins Combined With Clinical-Demographic Measures.

Identification of individuals at high risk of developing Parkinson disease (PD) several years before diagnosis is crucial for developing treatments to prevent or delay neurodegeneration. This study aimed to develop predictive models for PD risk that combine plasma proteins and easily accessible clinical-demographic variables. Using data from the UK Biobank (UKB), which recruited participants across the United Kingdom, we conducted a longitudinal study to identify predictors for incident PD. Participants with baseline plasma proteins and no PD were included. Through machine learning, we narrowed down predictors from a pool of 1,463 plasma proteins and 93 clinical-demographic. These predictors were then externally validated using the Parkinson's Progression Marker Initiative (PPMI) cohort. To further investigate the temporal trends of predictors, a nested case-control study was conducted within the UKB. A total of 52,503 participants without PD (median age 58, 54% female) were included. Over a median follow-up duration of 14.0 years, 751 individuals were diagnosed with PD (median age 65, 37% female). Using a forward selection approach, we selected a panel of 22 plasma proteins for optimal prediction. Using an ensemble tree-based Light Gradient Boosting Machine (LightGBM) algorithm, the model achieved an area under the receiver operating characteristic curve (AUC) of 0.800 (95% CI 0.785-0.815). The LightGBM prediction model integrating both plasma proteins and clinical-demographic variables demonstrated enhanced predictive accuracy, with an AUC of 0.832 (95% CI 0.815-0.849). Key predictors identified included age, years of education, history of traumatic brain injury, and serum creatinine. The incorporation of 11 plasma proteins (neurofilament light, integrin subunit alpha V, hematopoietic PGD synthase, histamine N-methyltransferase, tubulin polymerization promoting protein family member 3, ectodysplasin A2 receptor, Latexin, interleukin-13 receptor subunit alpha-1, BAG family molecular chaperone regulator 3, tryptophanyl-TRNA synthetase, and secretogranin-2) augmented the model's predictive accuracy. External validation in the PPMI cohort confirmed the model's reliability, producing an AUC of 0.810 (95% CI 0.740-0.873). Notably, alterations in these predictors were detectable several years before the diagnosis of PD. Our findings support the potential utility of a machine learning-based model integrating clinical-demographic variables with plasma proteins to identify individuals at high risk for PD within the general population. Although these predictors have been validated by PPMI, additional validation in a more diverse population reflective of the general community is essential.

Non-classical monocytes scavenge the growth factor CSF1 from endothelial cells in the peripheral vascular tree to ensure survival and homeostasis

Unlike sessile macrophages that occupy specialized tissue niches, non-classical monocytes (NCMs)-circulating phagocytes that patrol and cleanse the luminal surface of the vascular tree-are characterized by constant movement. Here, we examined the nature of the NCM's nurturing niche. Expression of the growth factor CSF1 on endothelial cells was required for survival of NCMs in the bloodstream. Lack of endothelial-derived CSF1 did not affect blood CSF1 concentration, suggesting that NCMs rely on scavenging CSF1 present on endothelial cells. Deletion of the transmembrane chemokine and adhesion factor CX3CL1 on endothelial cells impaired NCM survival. Mechanistically, endothelial-derived CX3CL1 and integrin subunit alpha L (ITGAL) facilitated the uptake of CSF1 by NCMs. CSF1 was produced by all tissular endothelial cells, and deletion of Csf1 in all endothelial cells except bone marrow sinusoids impaired NCM survival, arguing for a model where the full vascular tree acts as a niche for NCMs and where survival and patrolling function are connected.

Metastasis and basement membrane-related signature enhances hepatocellular carcinoma prognosis and diagnosis by integrating single-cell RNA sequencing analysis and immune microenvironment assessment

BackgroundHepatocellular carcinoma (HCC) is the most common type of primary liver cancer and second leading cause of cancer-related deaths worldwide. The heightened mortality associated with HCC is largely attributed to its propensity for metastasis, which cannot be achieved without remodeling or loss of the basement membrane (BM). Despite advancements in targeted therapies and immunotherapies, resistance and limited efficacy in late-stage HCC underscore the urgent need for better therapeutic options and early diagnostic biomarkers. Our study aimed to address these gaps by investigating and evaluating potential biomarkers to improve survival outcomes and treatment efficacy in patients with HCC.MethodIn this study, we collected the transcriptome sequencing, clinical, and mutation data of 424 patients with HCC from The Cancer Genome Atlas (TCGA) and 240 from the International Cancer Genome Consortium (ICGC) databases. We then constructed and validated a prognostic model based on metastasis and basement membrane-related genes (MBRGs) using univariate and multivariate Cox regression analyses. Five immune-related algorithms (CIBERSORT, QUANTISEQ, MCP counter, ssGSEA, and TIMER) were then utilized to examine the immune landscape and activity across high- and low-risk groups. We also analyzed Tumor Mutation Burden (TMB) values, Tumor Immune Dysfunction and Exclusion (TIDE) scores, mutation frequency, and immune checkpoint gene expression to evaluate immune treatment sensitivity. We analyzed integrin subunit alpha 3 (ITGA3) expression in HCC by performing single-cell RNA sequencing (scRNA-seq) analysis using the TISCH 2.0 database. Lastly, wound healing and transwell assays were conducted to elucidate the role of ITGA3 in tumor metastasis.ResultsPatients with HCC were categorized into high- and low-risk groups based on the median values, with higher risk scores indicating worse overall survival. Five immune-related algorithms revealed that the abundance of immune cells, particularly T cells, was greater in the high-risk group than in the low-risk group. The high-risk group also exhibited a higher TMB value, mutation frequency, and immune checkpoint gene expression and a lower tumor TIDE score, suggesting the potential for better immunotherapy outcomes. Additionally, scRNA-seq analysis revealed higher ITGA3 expression in tumor cells compared with normal hepatocytes. Wound healing scratch and transwell cell migration assays revealed that overexpression of the MBRG ITGA3 enhanced migration of HCC HepG2 cells.ConclusionThis study established a direct molecular correlation between metastasis and BM, encompassing clinical features, tumor microenvironment, and immune response, thereby offering valuable insights for predicting clinical outcomes and immunotherapy responses in HCC.

Investigation of coagulation and proteomics profiles in symptomatic feline hypertrophic cardiomyopathy and healthy control cats

BackgroundHypertrophic cardiomyopathy (HCM) is a crucial heart disease in cats. The clinical manifestations of HCM comprise pulmonary edema, dyspnea, syncope, arterial thromboembolism (ATE), and sudden cardiac death. D-dimer and prothrombin time (PT) are powerful biomarkers used to assess coagulation function. Dysregulation in these two biomarkers may be associated with HCM in cats. This study aims to assess D-dimer levels, PT, and proteomic profiling in healthy cats in comparison to cats with symptomatic HCM.ResultsTwenty-nine client-owned cats with HCM were enrolled, including 15 healthy control and 14 symptomatic HCM cats. The D-dimer concentration and PT were examined. Proteomic analysis was conducted by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry and liquid chromatography-tandem mass spectrometry (LC-MS/MS). In symptomatic cats, D-dimer levels were statistically significantly higher (mean ± SEM: 372.19 ng/ml ± 58.28) than in healthy cats (mean ± SEM: 208.54 ng/ml ± 10.92) with P-value of less than 0.01, while PT was statistically significantly lower in symptomatic cats (mean ± SEM: 9.8 s ± 0.15) compared to healthy cats (mean ± SEM: 11.08 s ± 0.23) with P-value of less than 0.0001. The proteomics analysis revealed upregulation of integrin subunit alpha M (ITGAM), elongin B (ELOB), and fibrillin 2 (FBN2) and downregulation of zinc finger protein 316 (ZNF316) and ectonucleoside triphosphate diphosphohydrolase 8 (ENTPD8) in symptomatic HCM cats. In addition, protein-drug interaction analysis identified the Ras signaling pathway and PI3K-Akt signaling pathway.ConclusionsCats with symptomatic HCM have higher D-dimer and lower PT than healthy cats. Proteomic profiles may be used as potential biomarkers for the detection and management of HCM in cats. The use of D-dimer as a biomarker for HCM detection and the use of proteomic profiling for a better understanding of disease mechanisms remain to be further studied in cats.

ITGAM sustains MAPK signaling and serves as an adverse prognostic factor and therapeutic target in acute myeloid leukemia.

Acute myeloid leukemia (AML) is the second most frequently occurring type of leukemia in adults. Despite breakthroughs in genetics, the prognosis of AML patients remains dismal. The aim of this study is to find new therapeutic targets and diagnostic markers for AML and to explore their mechanisms of action. The expression patterns of integrin subunit alpha M (ITGAM) were investigated across different cell types using the Human Protein Atlas (HPA) database. The ITGAM levels across cancer types were analyzed using the Gene Expression Profiling Interactive Analysis (GEPIA) database. Prognostic correlations in AML individuals were evaluated using The Cancer Genome Atlas (TGCA) database. ITGAM-associated functions were evaluated by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. The AML cells were transfected with short-hairpin RNA targeting ITGAM or a control, and subsequently subjected to analysis in order to ascertain the impact of ITGAM on proliferation and apoptosis. The expression of ITGAM was significantly higher in the AML patient samples compared to the control samples. High ITGAM expression was significantly associated with poor overall survival (OS). The knockdown of ITGAM in the AML cells resulted in a decrease in proliferation and an increase in apoptosis. This was accompanied by cell cycle arrest at the G1 phase and a downregulation of protein production for cyclin D1, cyclin E1, cyclin-dependent kinase 2 (CDK2), and cyclin-dependent kinase 4 (CDK4). A pathway analysis and a western blot analysis revealed that ITGAM positively regulated mitogen-activated protein kinase (MAPK) signaling by silencing attenuated p38 MAPK (P38), c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase (ERK) phosphorylation, while the total protein levels remained unchanged. ITGAM can serve as a potential prognostic biomarker and therapeutic target for AML. ITGAM production was elevated in AML and indicated poor survival. Silencing ITGAM suppressed AML cell viability and induced apoptosis by blocking cell cycle progression, likely by impeding the activation of the MAPK pathway. Further investigations that directly target the ITGAM-MAPK axis may offer novel strategies for mitigating AML pathogenesis and overcoming chemotherapy resistance.

Polymorphisms of ITGA9 Gene and Their Correlation with Milk Quality Traits in Yak (Bos grunniens).

A single-nucleotide polymorphism (SNP) is a genome-level trait that arises from a variation in a single nucleotide, leading to diversity in DNA sequences. SNP screening is commonly used to provide candidate genes for yak breeding efforts. Integrin Subunit Alpha 9 (ITGA9) is an integrin protein. It plays an important role in cell adhesion, signalling, and other processes. The aim of this study was to discuss the association between genetic polymorphisms in the ITGA9 gene and milk quality traits and to identify potential molecular marker loci for yak breeding quality. We genotyped 162 yaks using an Illumina Yak cGPS 7K liquid chip and identified the presence of polymorphisms at nine SNP loci in the ITGA9 gene of yaks. The results showed that the mutant genotypes in the loci g.285,808T>A, g.306,600T>C, and g.315,413C>T were positively correlated with the contents of casein, protein, total solids (TS), and solid nonfat (SNF) in yak milk. In other loci, heterozygous genotypes had a positive correlation with nutrient content in yak milk. Then, two ITGA9 haplotype blocks were constructed based on linkage disequilibrium, which facilitated a more accurate screening of ITGA9 as a candidate gene for yak milk quality improvement. In conclusion, we identified SNPs and haplotype blocks related to yak milk quality traits and provided genetic resources for marker-assisted selection in yak breeding.

The Rac pathway prevents cell fragmentation in a nonprotrusively migrating leader cell during C. elegans gonad organogenesis

The C.elegans hermaphrodite distal tip cell (DTC) leads gonadogenesis. Loss-of-function mutations in a C.elegans ortholog of the Rac1 GTPase (ced-10) and its GEF complex (ced-5/DOCK180, ced-2/CrkII, ced-12/ELMO) cause gonad migration defects related to directional sensing; we discovered an additional defect class of gonad bifurcation in these mutants. Using genetic approaches, tissue-specific and whole-body RNAi, and invivo imaging of endogenously tagged proteins and marked cells, we find that loss of Rac1 or its regulators causes the DTC to fragment as it migrates. Both products of fragmentation-the now-smaller DTC and the membranous patch of cellular material-localize important stem cell niche signaling (LAG-2 ligand) and migration (INA-1/integrin subunit alpha) factors to their membranes, but only one retains the DTC nucleus and therefore the ability to maintain gene expression over time. The enucleate patch can lead a bifurcating branch off the gonad arm that grows through germ cell proliferation. Germ cells in this branch differentiate as the patch loses LAG-2 expression. While the nucleus is surprisingly dispensable for aspects of leader cell function, it is required for stem cell niche activity long term. Prior work found that Rac1-/-;Rac2-/- mouse erythrocytes fragment; in this context, our new findings support the conclusion that maintaining a cohesive but deformable cell is a conserved function of this important cytoskeletal regulator.

Integrin subunit alpha 5 maintains mitochondrial function in ox-LDL-induced cardiac microvascular endothelial cells via activating the PI3K/AKT signaling pathway.

Cardiac microvascular endothelial cells (CMECs) assume a pivotal role in the regulation of blood flow, and their impairment precipitates a spectrum of pathological transformations. Our previous study unveiled a notable mitigation of CMECs dysfunction through the intervention of integrin subunit alpha 5 (ITGA5), a member of the integrin protein family. This study delves into the effect of ITGA5 on the mitochondrial function in CMECs and reveals the regulation pathway. CMECs were stimulated with oxidized low-density lipoprotein (ox-LDL) to mimic coronary artery disease (CAD). The effects of ITGA5 on diverse facets of CMEC behavior, encompassing viability, apoptosis, angiogenesis, oxidative stress, and mitochondrial function, was systematically ascertained. Employing the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway as a focal point of investigation, the mediation of this pathway was substantiated utilizing the PI3K inhibitor LY294002. ITGA5 overexpression exerted a mitigating influence upon the ox-LDL-induced detriment to CMECs, manifested as increased viability, angiogenesis, mitochondrial function, and diminished apoptosis and oxidative stress. The counteraction of these salubrious effects by the administration of the PI3K inhibitor attests to the engagement of the PI3K/AKT signaling pathway. Overall, this study has discerned that ITGA5 activates the PI3k/Akt signaling pathway to orchestrate mitochondrial function and diminish ox-LDL-induced CMEC dysfunction. Thus, the targeted amelioration of this cellular injury emerges as a strategically pivotal endeavor for the prevention and amelioration of this ailment.

Cross-species single-cell analysis uncovers the immunopathological mechanisms associated with IgA nephropathy progression.

IgA nephropathy (IgAN) represents the main cause of renal failure, while the precise pathogenetic mechanisms have not been fully determined. Herein, we conducted a cross-species single-cell survey on human IgAN and mouse and rat IgAN models to explore the pathogenic programs. Cross-species single-cell RNA sequencing (scRNA-Seq) revealed that the IgAN mesangial cells (MCs) expressed high levels of inflammatory signatures CXCL12, CCL2, CSF1, and IL-34 and specifically interacted with IgAN macrophages via the CXCL12/CXCR4, CSF1/IL-34/CSF1 receptor, and integrin subunit alpha X/integrin subunit alpha M/complement C3 (C3) axes. IgAN macrophages expressed high levels of CXCR4, PDGFB, triggering receptor expressed on myeloid cells 2, TNF, and C3, and the trajectory analysis suggested that these cells derived from the differentiation of infiltrating blood monocytes. Additionally, protein profiling of 21 progression and 28 nonprogression IgAN samples revealed that proteins CXCL12, C3, mannose receptor C-type 1, and CD163 were negatively correlated with estimated glomerular filtration rate (eGFR) value and poor prognosis (30% eGFR as composite end point). Last, a functional experiment revealed that specific blockade of the Cxcl12/Cxcr4 pathway substantially attenuated the glomerulus and tubule inflammatory injury, fibrosis, and renal function decline in the mouse IgAN model. This study provides insights into IgAN progression and may aid in the refinement of IgAN diagnosis and the optimization of treatment strategies.

Improvement of skin wound healing by giant salamander skin mucus gel wrapped with bone marrow mesenchymal stem cells via affecting integrin family molecules.

Traditional bandages, gauze, and cotton balls are increasingly insufficient for addressing complex war injuries characterized by severe bleeding and diverse wound conditions. The giant salamander, a species of high medical value, secretes a unique mucus when stimulated, which has potential applications in wound care. Giant salamander skin mucus gel dressing wrapped with bone marrow mesenchymal stem cells (BMSCs-GSSM-gel) was prepared and validated. Skin wound injury of rabbit and mouse models were established. Hematoxylin and Eosin, Masson's trichrome, and Sirius red staining were performed. The platelet aggregation rate and coagulation items were measured. Transcriptome sequencing was performed to find potential differential expression genes. Preparation and characterization of BMSCs-GSSM-gel were performed, and BMSCs-GSSM-gel particles with a diameter of about 200 nm were obtained. BMSCs-GSSM-gel accelerated wound healing in both rabbit and mouse models. BMSCs-GSSM-gel significantly promoted hemostasis via increasing platelet aggregation rate and fibrinogen, but decreasing activated partial thromboplastin time, thrombin time, and prothrombin time. BMSCs-GSSM-gel treatment significantly impacted several genes associated with cell adhesion, inflammatory response, collagen-containing extracellular matrix, and the positive regulation of cell migration based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Integrin Subunit Beta 4 (ITGB4), Integrin Subunit Alpha 3 (ITGA3), and Laminin Subunit Beta 3 (LAMB3) might be involved in the wound healing process by BMSCs-GSSM-gel. We proved the BMSCs-GSSM-gel greatly improved the skin wound healing, and it might play a crucial role in the application fields of skin damage repair.

RAC1-mediated integrin alpha-6 expression in E-cadherin-deficient gastric cancer cells promotes interactions with the stroma and peritoneal dissemination

Diffuse-type gastric cancer (DGC) is a subtype of gastric cancer that is prone to peritoneal dissemination, with poor patient prognosis. Although intercellular adhesion loss between cancer cells is a major characteristic of DGCs, the mechanism underlying the alteration in cell-to-extracellular matrix (ECM) adhesion is unclear. We investigated how DGCs progress and cause peritoneal dissemination through interactions between DGC cells and the tumour microenvironment (TME). P53 knockout and KRASG12V-expressing (GAN-KP) cells and Cdh1-deleted GAN-KP (GAN-KPC) cells were orthotopically transplanted into the gastric wall to mimic peritoneal dissemination. The GAN-KPC tumour morphology was similar to that of human DGCs containing abundant stroma. RNA sequencing revealed that pathways related to Rho GTPases and integrin-ECM interactions were specifically increased in GAN-KPC cells compared with GAN-KP cells. Notably, we found that Rac Family Small GTPase 1 (RAC1) induces Integrin Subunit Alpha 6 (ITGA6) trafficking, leading to its enrichment on the GC cell membrane. Fibroblasts activate the FAK/AKT pathway in GC cells by mediating extracellular matrix (ECM)-Itga6 interactions, exacerbating the malignant phenotype. In turn, GC cells induce abnormal expression of fibroblast collagen and its transformation into cancer-associated fibroblasts (CAFs), resulting in DGC-like subtypes. These findings indicate that Cdh1 gene loss leads to abnormal expression and changes in the subcellular localization of ITGA6 through RAC1 signalling. The latter, through interactions with CAFs, allows for peritoneal dissemination.

ITGAL expression in non-small-cell lung cancer tissue and its association with immune infiltrates.

Integrin subunit alpha L (ITGAL) encodes an integrin component of LFA-1 and is a membrane receptor molecule widely expressed on leukocytes. It plays a key role in the interaction between white blood cells and other cells. There was a significant correlation between the expression of ITGAL and the tumor microenvironment in a number of cancers. However, experimental studies targeting ITGAL and immune cell infiltration in non-small-cell lung cancer (NSCLC) and the response to immune checkpoint inhibitor therapy are lacking. Data were obtained from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and Clinical Proteomic Tumor Analysis Consortium (CPTAC) databases to explore the relationship between ITGAL expression and prognosis, as well as the immune cell infiltration in patients with NSCLC. In addition, immunohistochemical staining for ITGAL and multiplex immunofluorescence (mIF) staining for ITGAL, CD20, CD68, CD4, and CD8 from tissue microarrays containing 118 tumor tissues and paired paracancerous tissues from patients with NSCLC were performed. The correlation between ITGAL expression and clinical factors, as well as the immunophenotypes of tumor-infiltrating immune cells, were also analyzed. In NSCLC tumor tissues, ITGAL was downregulated compared with matched paracancerous tissues, and low ITGAL expression was associated with a poor prognosis of NSCLC patients. Subsequently, immunohistochemistry results for tissue microarray showed that ITGAL expression was mainly elevated in tumor stroma and areas with highly infiltrated immune cells. ITGAL expression was higher in paracancerous tissues than tumor tissues. Furthermore, mIF results indicated that the patients with ITGAL-high expression tend had significantly higher CD8+ T cells, CD68+ macrophages, CD4+ T cells, and CD20+ B cells infiltration in their tumor tissues. Immunophenotypes were classified into three categories, that is deserted, excluded, and inflamed types, according to each kind of immune cell distribution in or around the cancer cell nest. MIF results showed that ITGAL expression level was correlated with the immunophenotypes. Furthermore, ITGAL expression was associated with the prognosis of NSCLC in patients with immune checkpoint inhibitor therapy and the patients with high ITGAL expression tends have better outcomes. ITGAL may be used as a biomarker for assessing the immune microenvironment in patients with NSCLC.

Abstract 2785: Beyond the role of transcobalamin 1 (TCN1) as a vitamin B12-binding protein in hepatocellular carcinoma

Abstract Hepatocellular carcinoma (HCC) is a common form of primary liver cancer and is associated with poor prognosis. Although sorafenib and lenvatinib have shown promising results in HCC treatment, their clinical benefits for patients have been limited owing to drug resistance and tumor relapse. This may be associated with the presence of tumor-initiating cells (T-ICs), which require further investigation to identify the key pathways or molecules involved in their regulation. Through in vitro enrichment of liver T-IC populations via a series of sphere passages under treatment with chemotherapeutic drugs, subsequent bulk RNA sequencing analysis identified a vitamin B-12 binding protein, transcobalamin 1 (TCN1), as the most upregulated molecule in such enriched T-IC populations. This result was consistent with the enrichment profiles of the stem cell signature in TCN1High HCC samples in the clinical dataset. TCN1 is a secretory protein expressed at high levels in salivary glands and glandular cells; however, its function beyond its native role as a vitamin B12-binding protein in the regulation of T-ICs is unclear. Using lentiviral shRNA overexpression and knockdown approaches, we identified a critical role for TCN1 in regulating the properties of T-ICs, including self-renewal, invasiveness, tumorigenicity, and drug resistance, through in vitro and in vivo assays. Clinically, we also observed a substantial increase in TCN1 mRNA signatures in HCC samples, which was associated with poor prognosis of HCC patients. By analyzing the TCGA-LIHC dataset with confirmation by immunoprecipitation, we report, for the first time, that TCN1 directly interacts with integrin subunit alpha 3 (ITGA3), thereby regulating the Notch signaling pathway. Furthermore, ELISA results revealed the presence of the secretory form of TCN1 in HCC cells, which exerts a T-IC-enhancing effect on HCC cells via autocrine regulation. In conclusion, our study provides novel insights into how TCN1 functions in HCC via a non-canonical mechanism, which goes beyond its conventional role as a vitamin B12-binding protein and uncovers a potential novel therapeutic target for HCC. Citation Format: Gregory Kenneth Muliawan, Carmen Oi Ning Leung, Terence Kin Wah Lee. Beyond the role of transcobalamin 1 (TCN1) as a vitamin B12-binding protein in hepatocellular carcinoma [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 2785.

Abstract 271: The effects of B-cell acute lymphoblastic leukemia cells on the adipose tissue microenvironment

Abstract Obesity increases the risk of developing many cancers, including breast, colon, kidney, and acute lymphoblastic leukemia (ALL). We have previously shown that ALL cells are recruited to migrate into adipose tissue, where they are protected from chemotherapy. In vitro, ALL cells induce significant changes in adipocytes which may contribute to these protective effects. However, how ALL cells affect the complex cell populations found in adipose tissue in vivo remains unknown. We therefore conducted single-cell RNA sequencing (scRNAseq) of the non-adipocyte stromal vascular fraction (SVF) from adipose tissue in obese mice with and without implanted syngeneic BCR-ABL positive ALL. Differential expression analysis was performed on individual SVF cell types to compare ALL vs. control adipose tissue and pathway enrichment analysis was used in identifying altered molecular processes between conditions. SVF from leukemic mice showed substantial differences in gene expression compared to control mice, suggesting that the ALL potentially induces changes in the microenvironment. Some of the largest differences were found in adipose tissue macrophages, and pathway enrichment analysis identified neutrophil recruitment and regulation as one of the top ten pathways upregulated in adipose macrophages from leukemic mice (4.10 fold enrichment, p<1 × 10-17 by Fisher’s exact test). Selected macrophage genes of interest in this pathway included CYBB (Cytochrome B-245 Beta), a neutrophil interaction gene that has been associated with macrophage infiltration in gastric cancer, was expressed 2.28 log2-fold higher in macrophages from leukemic compared to nonleukemic mice (p<1 × 10−99 by Wilcoxon test). ITGAL (Integrin subunit alpha L), which has been shown to be involved in neutrophil recruitment and implicated in cancer cell growth and transformation was expressed 2.85 log2-fold higher in macrophages from leukemic mice (p<1 × 10−99). Interestingly, adipose from leukemic mice showed a population of neutrophils (1.9% of SVF cells), while neutrophils were largely absent in adipose from nonleukemic mice (<0.1% of SVF cells), which is consistent with macrophage involvement in neutrophil recruitment. Our findings highlight the importance of adipose tissue in the leukemia microenvironment and show that ALL cells can influence this microenvironment in complex ways. Further work will confirm and investigate these cell-cell interactions, potentially improving our understanding of how adipose tissue contributes to cancer mortality. Citation Format: Jia Tan, Michael Cohen, Jessica Ding, In Sook Ahn, Xia Yang, Steven D. Mittelman. The effects of B-cell acute lymphoblastic leukemia cells on the adipose tissue microenvironment [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 271.

The Role of Integrin Subunit Alpha 2 (ITGA2) in Pancreatic Cancer Progression

Background: Pancreatic cancer is a relatively uncommon type of cancer, although it is often very aggressive and highly metastases to other parts of the body. Investigating a potential gene marker or gene targeted therapy can improve the patient’s early prognosis and/or treatment. Objectives: In this study, we identify Integrin Subunit Alpha 2 (ITGA2) as a potential target in inhibiting pancreatic cancer progression. Materials and Methods: Cell cycle analysis, gene expression level, and cell proliferation assay are implanted in this study as investigational methods. Two-tailed student's t test is used to compare between the studied groups. Results: Cell cycle analysis for the transformed cell lines revealed increasing in G0/G1 phase and entering the cells the cell cycle arrest (quiescence) after knocking down ITGA2 expression. On the other hand, knocking down the ITGA2 effect, the mesenchymal to epithelial transition and the migration possibility of the cell lines by inhibiting the expression of metastatic marker vimentin. Furthermore, ITGA2 can manipulate the tumor microenvironment by downregulating extracellular matrix proteins (ECM-proteins) LAMB3, and LAMC2. Conclusion: ITGA2 downregulation reduces the cell proliferation, induces the cell cycle arrest, and reduce the possibility of metastasis in pancreatic cancer.

Endothelial cell-derived extracellular vesicles expressing surface VCAM1 promote sepsis-related acute lung injury by targeting and reprogramming monocytes.

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a common life-threatening syndrome with no effective pharmacotherapy. Sepsis-related ARDS is the main type of ARDS and is more fatal than other types. Extracellular vesicles (EVs) are considered novel mediators in the development of inflammatory diseases. Our previous research suggested that endothelial cell-derived EVs (EC-EVs) play a crucial role in ALI/ARDS development, but the mechanism remains largely unknown. Here, we demonstrated that the number of circulating EC-EVs was increased in sepsis, exacerbating lung injury by targeting monocytes and reprogramming them towards proinflammatory macrophages. Bioinformatics analysis and further mechanistic studies revealed that vascular cell adhesion molecule 1 (VCAM1), overexpressed on EC-EVs during sepsis, activated the NF-κB pathway by interacting with integrin subunit alpha 4 (ITGA4) on the monocyte surface, rather than the tissue resident macrophage surface, thereby regulating monocyte differentiation. This effect could be attenuated by decreasing VCAM1 levels in EC-EVs or blocking ITGA4 on monocytes. Furthermore, the number of VCAM1+ EC-EVs was significantly increased in patients with sepsis-related ARDS. These findings not only shed light on a previously unidentified mechanism underling sepsis-related ALI/ARDS, but also provide potential novel targets and strategies for its precise treatment.

ITGAM-mediated macrophages contribute to basement membrane damage in diabetic nephropathy and atherosclerosis

BackgroundDiabetic nephropathy (DN) and atherosclerosis (AS) are prevalent and severe complications associated with diabetes, exhibiting lesions in the basement membrane, an essential component found within the glomerulus, tubules, and arteries. These lesions contribute significantly to the progression of both diseases, however, the precise underlying mechanisms, as well as any potential shared pathogenic processes between them, remain elusive.MethodsOur study analyzed transcriptomic profiles from DN and AS patients, sourced from the Gene Expression Omnibus database. A combination of integrated bioinformatics approaches and machine learning models were deployed to identify crucial genes connected to basement membrane lesions in both conditions. The role of integrin subunit alpha M (ITGAM) was further explored using immune infiltration analysis and genetic correlation studies. Single-cell sequencing analysis was employed to delineate the expression of ITGAM across different cell types within DN and AS tissues.ResultsOur analyses identified ITGAM as a key gene involved in basement membrane alterations and revealed its primary expression within macrophages in both DN and AS. ITGAM was significantly correlated with tissue immune infiltration within these diseases. Furthermore, the expression of genes encoding core components of the basement membrane was influenced by the expression level of ITGAM.ConclusionOur findings suggest that macrophages may contribute to basement membrane lesions in DN and AS through the action of ITGAM. Moreover, therapeutic strategies that target ITGAM may offer potential avenues to mitigate basement membrane lesions in these two diabetes-related complications.