MUC1 promotes cervical squamous cell carcinoma through ERK phosphorylation-mediated regulation of ITGA2/ITGA3.

In contrast to the decreasing trends in developed countries, the incidence and mortality rates of cervical squamous cell carcinoma in China have increased significantly. The screening and identification of reliable biomarkers and candidate drug targets for cervical squamous cell carcinoma are urgently needed to improve the survival rate and quality of life of patients. In this study, we demonstrated that the expression of MUC1 was greater in neoplastic tissues than in non-neoplastic tissues of the cervix, and cervical squamous cell carcinoma patients with high MUC1 expression had significantly worse overall survival than did those with low MUC1 expression, indicating its potential for early diagnosis of cervical squamous cell carcinoma. Next, we explored the regulatory mechanism of MUC1 in cervical squamous cell carcinoma. MUC1 could upregulate ITGA2 and ITGA3 expression via ERK phosphorylation, promoting the proliferation and metastasis of cervical cancer cells. Further knockdown of ITGA2 and ITGA3 significantly inhibited the tumorigenesis of cervical cancer cells. Moreover, we designed a combination drug regimen comprising MUC1-siRNA and a novel ERK inhibitor in vivo and found that the combination of these drugs achieved better results in animals with xenografts than did MUC1 alone. Overall, we discovered a novel regulatory pathway, MUC1/ERK/ITGA2/3, in cervical squamous cell carcinoma that may serve as a potential biomarker and therapeutic target in the future.

MUC1 is overexpressed in cervical squamous cell carcinoma. MUC1 regulates ERK phosphorylation, and subsequently upregulates ITGA2 and ITGA3 expression to promote tumorigenesis in cervical squamous cell carcinoma. A combination drug regimen targeting MUC1 and ERK achieved better results compared than MUC1 alone.

Identifying the prognosis implication, immunotherapy response prediction value, and potential targeted compound inhibitors of integrin subunit α3 (ITGA3) in human cancers.

The integrin subunit α3 (ITGA3) is a member of the integrin alpha chain protein family, which could promote progression, metastasis, and invasion in some cancers. Still, its function in the tumor microenvironment (TME), cancer prognosis, and immunotherapy remains unclear. A multifaceted analysis of ITGA3 in pan-cancer utilizing various databases and online web tools revealed ITGA3 was aberrantly expressed in tumor tissues and upregulated in most cancers, which may be related to ITGA3 genomic alterations and methylation modification. In addition, ITGA3 was significantly correlated with the poor or better prognosis of cancer patients, immune-related pathways in hallmark, immune infiltration, and immune checkpoints, revealing a biological function of ITGA3 in the tumor progression, tumor microenvironment, and tumor immunity. We also found that ITGA3 could predict the response to tumor immunotherapy based on cytokine-treated samples and immunotherapy cohorts. ITGA3 may participate in shaping and regulating the tumor microenvironment to affect the tumor immune response, which was a promising immunotherapy response predictive biomarker and potential therapeutic target to work synergistically with cancer immunotherapy to boost the response and efficacy. Finally, potential targeted compound inhibitors and sensitive drugs were screened using databases ConnectivityMap (CMap) and CellMiner, and AutoDock Tools was used for molecular docking.

FTO Knockdown-Mediated Maturation of miR-383-5p Inhibits Malignant Advancement of Pancreatic Cancer by Targeting ITGA3.

m6A demethylase FTO is confirmed to be involved in pancreatic cancer progression. FTO regulates miRNA processing. To investigate the regulatory effect of FTO on miR-383-5p and its role in pancreatic cancer. The expression of miR-383-5p, ITGA3, and FTO was predicted using bioinformatic analysis in tissues and was measured using qPCR in cells. Cell biological functions were investigated using MTT assay, Transwell assay, sphere formation assay, and qPCR. The targeting relationship between miR-383-5p and ITGA3 was evaluated using the dual-luciferase reporter assay. The effect of FTO on miR-383-5p processing was evaluated using RIP and MeRIP assay. FTO expression was upregulated in pancreatic cancer and silencing of FTO promoted the processing of miR-383-5p in an m6A-dependent manner. m6A-modified miRNA processing was recognized by IGF2BP1. Downregulation of miR-383-5p reversed FTO knockdown-induced inhibition of cellular processes. The FTO/miR-383-5p/ITGA3 axis facilitated cell viability, metastasis, and stemness in pancreatic cancer.

ITGA3 acts as a purity-independent biomarker of both immunotherapy and chemotherapy resistance in pancreatic cancer: bioinformatics and experimental analysis.

Contribution of integrin superfamily genes to treatment resistance remains uncertain. Genome patterns of thirty integrin superfamily genes were analyzed of using bulk and single-cell RNA sequencing, mutation, copy number, methylation, clinical information, immune cell infiltration, and drug sensitivity data. To select the integrins that are most strongly associated with treatment resistance in pancreatic cancer, a purity-independent RNA regulation network including integrins were constructed using machine learning. The integrin superfamily genes exhibit extensive dysregulated expression, genome alterations, epigenetic modifications, immune cell infiltration, and drug sensitivity, as evidenced by multi-omics data. However, their heterogeneity varies among different cancers. After constructing a three-gene (TMEM80, EIF4EBP1, and ITGA3) purity-independent Cox regression model using machine learning, ITGA3 was identified as a critical integrin subunit gene in pancreatic cancer. ITGA3 is involved in the molecular transformation from the classical to the basal subtype in pancreatic cancer. Elevated ITGA3 expression correlated with a malignant phenotype characterized by higher PD-L1 expression and reduced CD8+ T cell infiltration, resulting in unfavorable outcomes in patients receiving either chemotherapy or immunotherapy. Our findings suggest that ITGA3 is an important integrin in pancreatic cancer, contributing to chemotherapy resistance and immune checkpoint blockade therapy resistance.

Integrin α3 Mediates Stemness and Invasion of Glioblastoma by Regulating POU3F2.

BACKGROUND: Glioblastoma (GBM) is an aggressive brain tumor. Integrins have been implicated in the malignancy of GBM. A recent study demonstrated that integrin α3 (ITGA3) promoted the invasion of breast cancer cells by regulating transcriptional factor POU3F2. However, whether this also happened in GBM remained unknown. METHODS: Therefore, we explored the relationship between ITGA3 and POU3F2 in GBM. We measured the expression of ITGA3 and POU3F2 in GBM tissues. We generated ITGA3 knockdown and POU3F2 knockdown GBM U87MG cells and the proliferation, migration and invasion, the expression of stemness markers and epithelial to mesenchymal transition (EMT) markers were measured. We transplanted ITGA3 knockdown and POU3F2 knockdown GBM U87MG cells into mice. The mice were treated with anti-ITGA3 antibody. The tumor sizes, the expression of stemness markers and epithelial-to-mesenchymal transition (EMT) markers were measured. RESULTS: Both ITGA3 and POU3F2 were upregulated in GBM tissues. Knocking down ITGA3 resulted in reduced expression of POU3F2. Knocking down ITGA3 and POU3F2 suppressed U87MG cells proliferation, migration and invasion, inhibited the expression of stemness markers and prevented epithelial- to-mesenchymal transition. The transplantation of ITGA3 knockdown and POU3F2 knockdown U87MG cells decreased tumor size. CONCLUSION: Anti-ITGA3 antibody treatment reduced the tumor size. ITGA3 regulates stemness and invasion of glioblastoma through POU3F2.

Zebrafish integrin a3b is required for cardiac contractility and cardiomyocyte proliferation.

In cardiac muscle cells, heterodimeric integrin transmembrane receptors are known to serve as mechanotransducers, translating mechanical force to biochemical signaling. However, the roles of many individual integrins have still not been delineated. In this report, we demonstrate that Itga3b is localized to the sarcolemma of cardiomyocytes from 24 to 96 hpf. We further show that heterozygous and homozygous itga3b/bdf mutant embryos display a cardiomyopathy phenotype, with decreased cardiac contractility and reduced cardiomyocyte number. Correspondingly, proliferation of ventricular and atrial cardiomyoctyes and ventricular epicardial cells is decreased in itga3b mutant hearts. The contractile dysfunction of itga3b mutants can be attributed to cardiomyocyte sarcomeric disorganization, including thin myofilaments with blurred and shortened Z-discs. Together, our results reveal that Itga3b localizes to the myocardium sarcolemma, and it is required for cardiac contractility and cardiomyocyte proliferation.

lncRNA ITGB8-AS1 functions as a ceRNA to promote colorectal cancer growth and migration through integrin-mediated focal adhesion signaling.

Long non-coding RNAs (lncRNAs) play critical roles in tumorigenesis and progression of colorectal cancer (CRC). However, functions of most lncRNAs in CRC and their molecular mechanisms remain uncharacterized. Here we found that lncRNA ITGB8-AS1 was highly expressed in CRC. Knockdown of ITGB8-AS1 suppressed cell proliferation, colony formation, and tumor growth in CRC, suggesting oncogenic roles of ITGB8-AS1. Transcriptomic analysis followed by KEGG analysis revealed that focal adhesion signaling was the most significantly enriched pathway for genes positively regulated by ITGB8-AS1. Consistently, knockdown of ITGB8-AS1 attenuated the phosphorylation of SRC, ERK, and p38 MAPK. Mechanistically, ITGB8-AS1 could sponge miR-33b-5p and let-7c-5p/let-7d-5p to regulate the expression of integrin family genes ITGA3 and ITGB3, respectively, in the cytosol of cells. Targeting ITGB8-AS1 using antisense oligonucleotide (ASO) markedly reduced cell proliferation and tumor growth in CRC, indicating the therapeutic potential of ITGB8-AS1 in CRC. Furthermore, ITGB8-AS1 was easily detected in plasma of CRC patients, which was positively correlated with differentiation and TNM stage, as well as plasma levels of ITGA3 and ITGB3. In conclusion, ITGB8-AS1 functions as a competing endogenous RNA (ceRNA) to regulate cell proliferation and tumor growth of CRC via regulating focal adhesion signaling. Targeting ITGB8-AS1 is effective in suppressing CRC cell growth and tumor growth. Elevated plasma levels of ITGB8-AS1 were detected in advanced-stage CRC. Thus, ITGB8-AS1 could serve as a potential therapeutic target and circulating biomarker in CRC.

Synthesis of scaffold-free, three dimensional, osteogenic constructs following culture of skeletal osteoprogenitor cells on glass surfaces.

BACKGROUND: Efficient differentiation of stem cells into three-dimensional (3D) osteogenic construct is still an unmet challenge. These constructs can be crucial for patients with bone defects due to congenital or traumatic reasons. The modulation of cell fate and function as a consequence of interaction with the physical and chemical properties of materials is well known. METHODS: The current study has examined the osteogenic differentiation potential of human skeletal populations following culture on glass surfaces, as a monolayer, or in glass tubes as a pellet culture. The 3D prosperities were assessed morphometrically and the differentiation was evaluated through molecular characterization as well as matrix formation. RESULTS: Early temporal expression of alkaline phosphatase expression of skeletal populations was observed following culture on glass surfaces. Skeletal populations seeded on glass tubes, adhered as a monolayer to the tube base and subsequently formed 3D pellets at the air -media interface. The pellets cultured on glass displayed 4.9 ± 1.3 times the weight and 2.9 ± 0.1 the diameter of their counterpart cultured in plastic tubes and displayed enhanced production of osteogenic matrix proteins, such a collagen I and osteonectin. The size and weight of the pellets correlated with surface area in contrast to cell numbers seeded. Global DNA methylation level was decreased in pellets cultured on glass. In contrast, gene expression analysis confirmed upregulation extracellular matrix proteins and osteogenesis-related growth factors. CONCLUSION: This simple approach to the culture of skeletal cells on glass tubes provides a scaffold-free, 3D construct platform for generating pellets enabling analysis and evaluation of tissue development and integration of multiple constructs with implications for tissue repair and regenerative application on scale-up.

A novel ITGA3 homozygous splice mutation in an ILNEB syndrome child with slow progression.

BACKGROUND AND AIMS: ILNEB (interstitial lung disease, nephrotic syndrome, epidermolysis bullosa) syndrome is caused by ITGA3 mutations. Demises usually happened at infancy. This study reports a complete ILNEB syndrome child with slow disease progression. MATERIALS AND METHODS: Clinical data and related specimens were collected. Genomic DNA was extracted for genetic sequencing. Integrin α3 expression was detected by western blotting and immunofluorescence staining. RESULTS: The patient was male. He experienced recurrent rashes shortly after birth. His sparse eyebrows and eyelashes gradually lost. The patient was vulnerable to respiratory infections and had recurrent fever after vaccine immunization after 4 years. He was found with nephrotic syndrome and polycystic renal dysplasia at 8 years and progressed to end-stage renal disease at 12 years. A chest Computed Tomography revealed intestinal lung disease at 8 years. Continuous oxygen supplementation was needed at 13 years. Counts of lymphocyte subsets revealed elevated percentage of double-negative T cells and activated T cells. Next-generation sequencing revealed a novel homozygous splice mutation c.2219 + 4A > Cin ITGA3 that was predicted to be deleterious. The mutation resulted in exon17 skipping with the loss of 80 bp in the mRNA. The aberrant integrin α3 mRNA level was lower compared to the healthy control. Integrin α3 protein was not detected in urine epithelial cells and skin of the patient. CONCLUSIONS: We report a patient harboring a novel ITGA3 homozygous splice mutation who presented with complete ILNEB syndrome but slow disease progression. Immune disorders were suspected.

CD9 and ITGA3 are regulated during HIV-1 infection in macrophages to support viral replication.

Monocytes/macrophages are important target cells for HIV-1. Here, we investigated whether HIV-1 induces changes in the macrophage gene expression profile to support viral replication. We observed that the macrophage gene expression profiles dramatically changed upon HIV-1 infection. The majority of the HIV-1 regulated genes were also differentially expressed in M2a macrophages. The biological functions associated with the HIV-1 induced gene expression profile in macrophages were mainly related to inflammatory responses. CD9 and ITGA3 were among the top genes upregulated upon HIV-1 infection. We showed that these genes support viral replication and that downregulation of these genes decreased HIV-1 replication in macrophages. Here we showed that HIV-1 infection of macrophages induces a gene expression profile that may dampen inflammatory responses. CD9 and ITGA3 were among the top genes regulated by HIV-1 and were shown to support viral production most likely at the level of viral budding and release.

Expression and prognostic potential of PLEK2 in head and neck squamous cell carcinoma based on bioinformatics analysis.

BACKGROUND: PLEK2 (pleckstrin) could bind to membrane-bound phosphatidylinositols and further promote cell spread. Recently, several studies have noted the importance of PLEK2 in tumor metastasis. However, the role of PLEK2 in head and neck squamous cell carcinoma (HNSCC) remains to be elucidated. METHODS: The PLEK2 expression in HNSCC was identified using Oncomine, Gene Expression Omnibus (GEO), UALCAN databases, and western blot analysis. Prognosis analysis was performed using Kaplan-Meier plotter, DriverDBv3, UALCAN, UCSC Xena, and GEO databases. Single-cell functional analysis was further performed using the cancerSEA database. The PLEK2-related co-expressed genes were identified, and gene set enrichment analysis was performed using LinkedOmics. Furthermore, the top 10 hub genes were identified using the cytoHubba plug-in of Cytoscape. Then, gene enrichment analysis, pathway activity, and drug sensitivity analyses of the hub genes were performed using the R package "clusterProfiler" and GSCAlite. Finally, the UCSC Xena browser was utilized to explore the hub gene most likely to play a synergic role with PLEK2 in HNSCC. RESULTS: Elevated expression of PLEK2 was observed in HNSCC and even in HNSCC subgroups based on diverse clinicopathological features, portending a poor prognosis in HNSCC. PLEK2 was correlated with metastasis and hypoxia in HNSCC, and the PLEK2-related co-expressed genes were mainly involved in the focal adhesion pathway. The top 10 hub genes were primarily enriched in focal adhesion, HPV infection, ECM-receptor interaction, and PI3K-AKT signaling pathway, and epithelial-mesenchymal transition pathway was activated. Furthermore, the expression levels of the hub genes were associated with sensitivity and resistance to various small molecules and anti-cancer drugs. Further study suggested that ITGA3 and PLEK2 might be viewed as inextricably linked in facilitating HNSCC metastasis. CONCLUSIONS: In general, PLEK2 might serve as a potential biomarker for the diagnosis of HNSCC and guide the development of targeted therapies for HNSCC.

ITGA3 Is Associated With Immune Cell Infiltration and Serves as a Favorable Prognostic Biomarker for Breast Cancer.

BACKGROUND: ITGA3 is a member of the integrin family, a cell surface adhesion molecule that can interact with extracellular matrix (ECM) proteins. The purpose of this study was to explore the significance of ITGA3 expression in the prognosis and clinical diagnosis of breast cancer patients. METHODS: Oncomine, the Human Protein Atlas (HPA) and UALCAN were used to analyze the expression of ITGA3 in various cancers. PrognoScan, GEPIA, Kaplan-Meier plotter and Easysurv were utilized to analyze the prognosis of ITGA3 in certain cancers. Based on TCGA data, a receiver operating characteristic (ROC) curve was used to evaluate the diagnostic performance of ITGA3 expression. cBio-Portal and MethSurv were used to evaluate the genomic mechanism. LinkedOmics, NetworkAnalyst and Metascape were used to build the signaling network. TIMER is a web server for comprehensive analysis of tumor infiltrating immune cells and tumor infiltrating lymphocytes (TILs). RESULTS: The expression of ITGA3 in normal breast tissues was greater than that in breast cancer tissues at both the mRNA and protein levels. High expression of ITGA3 was associated with better prognosis of breast cancer patients. ROC analysis indicated that ITGA3 had significant diagnostic value. Genomic analysis revealed that promoter methylation of ITGA3 leads to transcriptional silencing, which may be one of the mechanisms underlying ITGA3 downregulation in BRCA. Immune infiltration analysis showed that ITGA3 may be involved in the recruitment of immune cells. CONCLUSIONS: This study identified ITGA3 as a novel biomarker to estimate the diagnosis and prognosis of breast cancer. In addition, ITGA3 is involved in ECM regulation and immune cell infiltration.

Detection of bladder cancer with aberrantly fucosylated ITGA3.

We describe a simple, non-invasive assay to identify fucosylated-glycoisoform of integrin alpha-3 (ITGA3) directly from unprocessed urine. ITGA3 was detected directly from the urine of bladder cancer (BlCa) (n = 13) and benign prostatic hyperplasia (BPH) (n = 9) patients with the use of lectins coated on europium-doped-nanoparticles (Eu3+-NPs). Lectin Ulex europaeus agglutinin-I (UEA) showed enhanced binding with BlCa-derived ITGA3. The evaluation with individual samples showed that a glycovariant ITGA3-UEA assay could significantly discriminate BlCa from BPH patients (p = 0.007). The detection of aberrantly fucosylated-isoform of ITGA3 from urine can be used to distinguish BlCa from age-matched benign controls in a simple sandwich assay.

Evaluation of ITGA3 as a Biomarker of Progression and Recurrence in Papillary Thyroid Carcinoma.

OBJECTIVE: To investigate the expression of ITGA3 and its association with clinical outcomes in papillary thyroid carcinoma (PTC). METHODS: The expression level, association with clinicopathologic characteristics, co-expressed genes, signaling pathways of ITGA3 in thyroid cancer were comprehensively analyzed using bioinformatics analysis through multiple public gene databases. PTC specimens and cell lines were used to verify the results of bioinformatics analysis. RESULTS: Data mining based on the Oncomine database revealed that ITGA3 expression in classical PTC and tall cell variant PTC was much higher than that in normal thyroid tissue except the follicular variant PTC. Analysis based on The Cancer Genome Atlas (TCGA) database showed that the expression of ITGA3 varies greatly in pathological stages, pathological types, tumor invasion stages, and lymph node metastasis stages of thyroid carcinoma. High expression level of ITGA3 was correlated with tumor regional invasion and lymph node metastasis. Multivariate analysis using logistic regression model showed that high expression of ITGA3 was a risk factor that associated with PTC recurrence and lymph node metastasis. Survival analysis showed that patients with high expression of ITGA3 in PTC had a poorer relapse-free survival (RFS) than patients with low expression of ITGA3 (P < 0.05). Immunohistochemistry experiments showed that the expression of ITGA3 in recurrent thyroid cancer tissues was stronger than that in no-recurrent thyroid cancer tissues (P < 0.05). Knockdown of ITGA3 by sh-RNA in PTC cell lines suppresses cell viability and invasive and migrating capacity. CONCLUSION: ITGA3 is overexpressed in PTC, especially in those with higher tumor invasion grades and lymph node metastasis, and was associated with recurrence and poor RFS of PTC. High expression of ITGA3 may have the potential role of predicting PTC recurrence and lymph node metastasis.

High integrin α3 expression is associated with poor prognosis in patients with non-small cell lung cancer.

BACKGROUND: We previously showed that α3ß1 integrin is a novel cancer biomarker and drug target in non-small cell lung cancer (NSCLC). This study characterized the integrin α3 (ITGA3) expression on patient specimens. METHODS: Tissue microarrays (TMAs) were prepared from archival tissue blocks containing 161 patients, which included 91 adenocarcinoma (LUAD), 46 squamous carcinomas (LUSC), and 24 other histology types. TMA sections were stained and scored for ITGA3 expression by immunohistochemistry (IHC). Kaplan-Meier curves and log-rank tests were used to compare overall survival (OS) between IHC score groups. Propensity-score-weighted Kaplan-Meier curves and weighted Cox models were used to adjust for covariate imbalance between IHC score groups. Logistic regression was used to determine ITGA3 transcriptome expression in NSCLC in The Cancer Genome Atlas (TCGA). RESULTS: ITGA3 IHC expression (1+ to 3+) was detected in 107/161 (66.5%) of the NSCLC samples, and was associated with poor prognosis at the edge of significance (HR =1.30, 95% CI: 0.99-1.71, P=0.056), but significant (P<0.05) in subgroups of female patients, smokers and tumors with grade I and II differentiation using propensity-score-weighted survival analysis after adjusting for confounders. Multivariate survival analysis based on multiple imputation for missing variables showed ITGA3 expression, old age and metastasis were associated with poor prognosis (P<0.05). ITGA3 IHC expression was associated with poor prognosis in LUSC (HR =2.27, P<0.05) but not in LUAD (HR =1.49, P=0.16). Median ITGA3 expression was significantly higher in LUAD than LUSC (P<0.0001) in the TCGA transcriptome datasets. Using a higher cutoff than LUSC (70.6 vs. 19.5 FPKM), high ITGA3 RNA expression was also associated with poor prognosis in LUAD (P=0.023). ITGA3 interacted with key genes regulating epithelial to mesenchymal transition, angiogenesis, invasion and metastasis in both LUAD and LUSC. CONCLUSIONS: High ITGA3 IHC expression was associated with poor prognosis in NSCLC patients. Further study is warranted for targeting α3ß1 integrin in NSCLC.

Interference with circBC048201 inhibits the proliferation, migration, and invasion of bladder cancer cells through the miR-1184/ITGA3 axis.

The abnormal expression of circular RNA (circRNA) is bound up with the progress of various human cancers. This study aimed to reveal the potential role and mechanism of circBC048201 in the proliferation, migration, and invasion of bladder cancer cells. Quantitative real-time PCR was performed to detect the expression of circBC048201. Cell Counting Kit-8, colony formation, and transwell migration and invasion assays were used to confirm the in vitro functions of circBC048201. Western blot, RNA pull-down, and dual-luciferase reporter gene experiments were performed to study the potential mechanism. circBC048201 was abnormally highly expressed in bladder cancer tissues and cells, and the interference with circBC048201 inhibited bladder cancer cell proliferation, migration, and invasion. From the potential mechanism analysis, our data suggested that circBC048201 and miR-1184, miR-1184 and ITGA3 could bind to each other, and the interference with circBC048201 repressed bladder cancer cell proliferation, migration, and invasion through the miR-1184/ITGA3 axis. In summary, our results showed that circBC048201 was abnormally highly expressed in bladder cancer tissues and cells, and the interference with circBC048201 inhibited the proliferation, migration, and invasion of bladder cancer cells through the miR-1184/ITGA3 axis.

MicroRNA­199a­5p suppresses cell proliferation, migration and invasion by targeting ITGA3 in colorectal cancer.

As a member of the integrin family, integrin α3ß1 (ITGA3) has been linked to intercellular communication and serves an important role in the signaling among cells and the extracellular matrix. MicroRNA (miR)­199a­5p has been demonstrated to be related to the pathogenesis and progression of multiple malignant diseases. However, the biological functions of miR­199a­5p and ITGA3 in colorectal cancer (CRC) have rarely been reported. The aim of the present study was to explore the roles of miR­199a­5p and ITGA3 in CRC. Immunohistochemistry staining and western blotting were applied to detect the protein expression of ITGA3 in CRC tissues and cells. Reverse transcription­quantitative PCR was performed to investigate the expression of miR­199a­5p and ITGA3 mRNA. HCT­116 cells were transfected with miR­199a­5p mimics, mimics control, short hairpin RNA targeting ITGA3, or pcDNA­ITGA3 for the functional experiments. Dual luciferase reporter assay was applied to confirm whether miR­199a­5p targeted the 3' untranslated region (3'UTR) of ITGA3. The MTT, Transwell and wound healing assays were used to evaluate the proliferation, invasion and migration of CRC cells. Immunofluorescence assay was used to monitor the epithelial­mesenchymal transition (EMT) biomarker expression. The results demonstrated downregulation of miR­199a­5p and upregulation of ITGA3 in CRC tissues and cell lines. miR­199a­5p mimics and knockdown of ITGA3 suppressed the proliferation, invasion and migration of CRC cells. Bioinformatics analysis and luciferase reporter assay indicated that miR­199a­5p targeted the 3'UTR of the ITGA3 transcript, and overexpression of ITGA3 reversed the tumor­suppressive effects of miR­199a­5p elevation. In addition, the immunofluorescence assay suggested that miR­199a­5p mimics suppressed the EMT of CRC cells, whereas the overexpression of ITGA3 restored this effect. In conclusion, miR­199a­5p may act as a tumor suppressor by targeting and negatively regulating ITGA3 in CRC.

ITGA3 interacts with VASP to regulate stemness and epithelial-mesenchymal transition of breast cancer cells.

BACKGROUND: The interaction of integrin and extracellular matrix (ECM) has a profound implication on pathological conditions such as tumor growth and infiltration. Related reports have confirmed that integrin α3 (ITGA3) influences the development of bladder cancer, head and neck cancer, colorectal cancer and other cancers. However, the mechanism of ITGA3 in breast cancer is unknown. METHODS: The impact of ITGA3 on the biological features of breast cancer cells was explored using the Transwell and wound healing assays. In addition, its influence on stemness of breast cancer cells was examined with the sphere formation assay. The possible mechanism by which ITGA3 regulates breast cancer was explored using Western blot. The interaction between ITGA3 and VASP was determined by co-immunoprecipitation and immunofluorescence staining assays. RESULTS: Results show that downregulation of ITGA3 promotes breast cancer cell proliferation, apoptosis, invasion and migration. Indeed, suppression of ITGA3 negatively regulates the stemness of breast cancer cells and EMT process. Our findings indicate that ITGA3 interacts with VASP and regulates its expression, and knockdown of ITGA3 inhibits the activity of the PI3K-AKT axis. CONCLUSION: Our results show that ITGA3-VASP modulates breast cancer cell stemness, EMT and PI3K-AKT pathways. Therefore, ITGA3 might be a druggable target for clinical breast cancer management.

Integrin-α3 Is a Functional Marker of Ex Vivo Expanded Human Long-Term Hematopoietic Stem Cells.

Transplantation of expanded hematopoietic stem cells (HSCs) and gene therapy based on HSC engineering have emerged as promising approaches for the treatment of hematological diseases. Nevertheless, the immunophenotype of cultured HSCs remains poorly defined. Here, we identify Integrin-α3 (ITGA3) as a marker of cultured human HSCs. Exploiting the pyrimidoindole derivative UM171 to expand cord blood (CB) cells, we show that ITGA3 expression is sufficient to separate the primitive EPCR+CD90+CD133+CD34+CD45RA- HSC population into two functionally distinct fractions presenting mostly short-term (ITGA3-) and both short-term and long-term (ITGA3+) repopulating potential. ITGA3+ cells exhibit robust multilineage differentiation potential, serial reconstitution ability in immunocompromised mice, and an HSC-specific transcriptomic signature. Moreover, ITGA3 expression is functionally required for the long-term engraftment of CB cells. Altogether, our results indicate that ITGA3 is a reliable marker of cultured human long-term repopulating HSCs (LT-HSCs) and represents an important tool to improve the accuracy of prospective HSC identification in culture.