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result(s) for
"Integrin alpha6 - genetics"
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Beneficial Effects of the Genus Aloe on Wound Healing, Cell Proliferation, and Differentiation of Epidermal Keratinocytes
2016
Aloe has been used as a folk medicine because it has several important therapeutic properties. These include wound and burn healing, and Aloe is now used in a variety of commercially available topical medications for wound healing and skin care. However, its effects on epidermal keratinocytes remain largely unclear. Our data indicated that both Aloe vera gel (AVG) and Cape aloe extract (CAE) significantly improved wound healing in human primary epidermal keratinocytes (HPEKs) and a human skin equivalent model. In addition, flow cytometry analysis revealed that cell surface expressions of β1-, α6-, β4-integrin, and E-cadherin increased in HPEKs treated with AVG and CAE. These increases may contribute to cell migration and wound healing. Treatment with Aloe also resulted in significant changes in cell-cycle progression and in increases in cell number. Aloe increased gene expression of differentiation markers in HPEKs, suggesting roles for AVG and CAE in the improvement of keratinocyte function. Furthermore, human skin epidermal equivalents developed from HPEKs with medium containing Aloe were thicker than control equivalents, indicating the effectiveness of Aloe on enhancing epidermal development. Based on these results, both AVG and CAE have benefits in wound healing and in treatment of rough skin.
Journal Article
Epithelial plasticity can generate multi-lineage phenotypes in human and murine bladder cancers
2020
Tumor heterogeneity is common in cancer, however recent studies have applied single gene expression signatures to classify bladder cancers into distinct subtypes. Such stratification assumes that a predominant transcriptomic signature is sufficient to predict progression kinetics, patient survival and treatment response. We hypothesize that such static classification ignores intra-tumoral heterogeneity and the potential for cellular plasticity occurring during disease development. We have conducted single cell transcriptome analyses of mouse and human model systems of bladder cancer and show that tumor cells with multiple lineage subtypes not only cluster closely together at the transcriptional level but can maintain concomitant gene expression of at least one mRNA subtype. Functional studies reveal that tumor initiation and cellular plasticity can initiate from multiple lineage subtypes. Collectively, these data suggest that lineage plasticity may contribute to innate tumor heterogeneity, which in turn carry clinical implications regarding the classification and treatment of bladder cancer.
Recent studies have utilized bulk tumour mRNA sequencing to classify bladder cancers into distinct subgroups. Here, the authors use single cell transcriptomic analysis and cell transplant studies to show that epithelial plasticity can generate basal, luminal and mesenchymal phenotypes in human and murine bladder cancers.
Journal Article
ITGA6 is directly regulated by hypoxia-inducible factors and enriches for cancer stem cell activity and invasion in metastatic breast cancer models
by
Brooks, Danielle L. Peacock
,
Gotwald, Lauren
,
Seagroves, Tiffany N.
in
Basic Helix-Loop-Helix Transcription Factors - metabolism
,
Biomedical and Life Sciences
,
Biomedicine
2016
Background
Hypoxia-inducible factors (HIFs) are well-established mediators of tumor growth, the epithelial to mesenchymal transition (EMT) and metastasis. In several types of solid tumors, including breast cancers, the HIFs play a critical role in maintaining cancer stem cell (CSC) activity. Thus, we hypothesized that HIFs may also regulate transcription of markers of breast CSC activity. One approach to enrich for breast cells with stem-like phenotypes is FACS sorting, in which sub-populations of live cells are gated based on the expression of cell surface antigens, including various integrin subunits. Integrin alpha 6 (ITGA6; CD49f) is routinely used in combination with other integrin subunits to enrich for breast stem cells by FACS. Integrins not only mediate interactions with the extracellular matrix (ECM), but also drive intracellular signaling events that communicate from the tumor microenvironment to inside of the tumor cell to alter phenotypes including migration and invasion.
Methods
We used two models of metastatic breast cancer (MBC), polyoma middle T (MMTV-PyMT) and MDA-MB-231 cells, to compare the expression of ITGA6 in wild type and knockout (KO) or knockdown cells. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays verified that ITGA6 is a direct HIF transcriptional target. We also used FACS sorting to enrich for CD49f
+
cells to compare tumorsphere formation, tumor initiating cell activity, invasion and HIF activity relative to CD49f
neg or low
cells. Knockdown of
ITGA6
significantly reduced invasion, whereas re-expression of ITGA6 in the context of HIF knockdown partially rescued invasion. A search of public databases also revealed that ITGA6 expression is an independent prognostic factor of survival in breast cancer patients.
Results
We report that ITGA6 is a HIF-dependent target gene and that high ITGA6 expression enhances invasion and tumor-initiating cell activities in models of MBC. Moreover, cells that express high levels of ITGA6 are enriched for HIF-1α expression and the expression of HIF-dependent target genes.
Conclusions
Our data suggest that HIF-dependent regulation of ITGA6 is one mechanism by which sorting for CD49f
+
cells enhances CSC and metastatic phenotypes in breast cancers. Our results are particularly relevant to basal-like breast cancers which express higher levels of the HIFα subunits, core HIF-dependent target genes and ITGA6 relative to other molecular subtypes.
Journal Article
Bald scalp in men with androgenetic alopecia retains hair follicle stem cells but lacks CD200-rich and CD34-positive hair follicle progenitor cells
by
Spiegel, Jeffrey H.
,
Stanton, David C.
,
Lee, Michelle
in
Alopecia
,
Alopecia - metabolism
,
Alopecia - pathology
2011
Androgenetic alopecia (AGA), also known as common baldness, is characterized by a marked decrease in hair follicle size, which could be related to the loss of hair follicle stem or progenitor cells. To test this hypothesis, we analyzed bald and non-bald scalp from AGA individuals for the presence of hair follicle stem and progenitor cells. Cells expressing cytokeratin15 (KRT15), CD200, CD34, and integrin, α6 (ITGA6) were quantitated via flow cytometry. High levels of KRT15 expression correlated with stem cell properties of small cell size and quiescence. These KRT15(hi) stem cells were maintained in bald scalp samples. However, CD200(hi)ITGA6(hi) and CD34(hi) cell populations--which both possessed a progenitor phenotype, in that they localized closely to the stem cell-rich bulge area but were larger and more proliferative than the KRT15(hi) stem cells--were markedly diminished. In functional assays, analogous CD200(hi)Itga6(hi) cells from murine hair follicles were multipotent and generated new hair follicles in skin reconstitution assays. These findings support the notion that a defect in conversion of hair follicle stem cells to progenitor cells plays a role in the pathogenesis of AGA.
Journal Article
Integrative Multi-Omics Characterization and Structural Insights into the Poorly Annotated Integrin ITGA6 X1X2 Isoform in Mammals
by
Castro Naser, Ximena Aixa
,
Tosatto, Silvio C. E.
,
Leonardi, Emanuela
in
Alternative Splicing
,
Animals
,
Annotations
2025
Background: Accurate annotation of gene isoforms remains one of the major obstacles in translating genomic data into meaningful biological insight. Laminin-binding integrins, particularly integrin α6 (ITGA6), exemplify this challenge through their complex splicing patterns. The rare ITGA6 X1X2 isoform, generated by the alternative inclusion of exons X1 and X2 within the β-propeller domain, has remained poorly characterized despite decades of integrin research. Methods: We combined comparative genomics across primates with targeted re-alignment to assess exon conservation and annotation fidelity; analyzed RNA-seq for exon-level usage; applied splice-site prediction to evaluate inclusion potential; surveyed cancer mutation resources for exon-specific variants; and used structural/disorder modeling to infer effects on the β-propeller. Results: Exon X2 is conserved at the genomic level but inconsistently annotated, reflecting the limitations of current annotation pipelines rather than genuine evolutionary loss. RNA-seq analyses reveal low but detectable expression of X2, consistent with weak splice site predictions that suggest strict regulatory control and condition-specific expression. Despite its rarity, recurrent mutations in exon X2 are reported in cancer datasets, implying possible roles in disease. Structural modeling further indicates that X2 contributes to a flexible, disordered region within the β-propeller domain, potentially influencing laminin binding or β-subunit dimerization. Conclusions: Altogether, our results suggest that ITGA6 X1X2 could be a rare, tightly regulated isoform with potential functional and pathological relevance.
Journal Article
iPSC-derived ITGA6-positive cells restore aqueous humor outflow in glaucoma eyes
2025
Decreased trabecular meshwork (TM) cellularity is a critical pathogenic cause of primary open-angle glaucoma, yet therapies to regenerate the decellularized TM are very limited. Induced pluripotent stem cell-derived TM-like cells (iPSC-TM) can efficiently restore aqueous humor outflow. Here, we conducted a multi-modal RNA sequencing analysis to characterize the molecular mechanisms underlying TM regeneration. Our clustering analysis identified a group of iPSC-derived alpha6 integrin-positive (iPSC-ITGA6
+
) cells with a distinct transcriptome that wasn’t observed in primary TM (pTM) cells. These iPSC-ITGA6
+
cells not only stimulate pTM proliferation but also facilitate the repopulation of the TM and Schlemm’s canal in glaucoma, with a much higher efficiency than other iPSC-TM subtypes. Interaction with iPSC-ITGA6
+
cells is characterized by the proliferation and rejuvenation of endogenous pTM cells, primarily through the transcription of long non-coding RNA nuclear paraspeckle assembly transcript1 and the abundance of paraspeckles within iPSC-ITGA6
+
cells. Enhancing paraspeckle assembly by MEN β-associated RNA promotes the rejuvenation and proliferation of pTM, suggesting a novel and promising approach for TM regeneration.
Exogenous iPSC-derived cells can activate endogenous cells to promote trabecular meshwork regeneration and restore aqueous humor outflow in glaucoma, providing insights into in situ regeneration, which may serve as an alternative to traditional cell therapy.
Journal Article
Hemidesmosome integrity protects the colon against colitis and colorectal cancer
by
De Arcangelis, Adèle
,
Siebert, Stéphanie
,
Chamaillard, Mathias
in
Adaptive Immunity
,
Adenocarcinoma
,
Adenocarcinoma - genetics
2017
ObjectiveEpidemiological and clinical data indicate that patients suffering from IBD with long-standing colitis display a higher risk to develop colorectal high-grade dysplasia. Whereas carcinoma invasion and metastasis rely on basement membrane (BM) disruption, experimental evidence is lacking regarding the potential contribution of epithelial cell/BM anchorage on inflammation onset and subsequent neoplastic transformation of inflammatory lesions. Herein, we analyse the role of the α6β4 integrin receptor found in hemidesmosomes that attach intestinal epithelial cells (IECs) to the laminin-containing BM.DesignWe developed new mouse models inducing IEC-specific ablation of α6 integrin either during development (α6ΔIEC) or in adults (α6ΔIEC-TAM).ResultsStrikingly, all α6ΔIEC mutant mice spontaneously developed long-standing colitis, which degenerated overtime into infiltrating adenocarcinoma. The sequence of events leading to disease onset entails hemidesmosome disruption, BM detachment, IL-18 overproduction by IECs, hyperplasia and enhanced intestinal permeability. Likewise, IEC-specific ablation of α6 integrin induced in adult mice (α6ΔIEC-TAM) resulted in fully penetrant colitis and tumour progression. Whereas broad-spectrum antibiotic treatment lowered tissue pathology and IL-1β secretion from infiltrating myeloid cells, it failed to reduce Th1 and Th17 response. Interestingly, while the initial intestinal inflammation occurred independently of the adaptive immune system, tumourigenesis required B and T lymphocyte activation.ConclusionsWe provide for the first time evidence that loss of IECs/BM interactions triggered by hemidesmosome disruption initiates the development of inflammatory lesions that progress into high-grade dysplasia and carcinoma. Colorectal neoplasia in our mouse models resemble that seen in patients with IBD, making them highly attractive for discovering more efficient therapies.
Journal Article
Thrombospondin 1 Promotes Cytoskeleton Remodeling, Dedifferentiation, and Pulmonary Metastasis through ITGA1 and ITGA6 in Osteosarcoma
by
Xu, Enjie
,
Wang, Yongjie
,
Zhu, Kunpeng
in
Bone Neoplasms - metabolism
,
Bone Neoplasms - pathology
,
Cell Dedifferentiation - genetics
2025
Dedifferentiation of osteosarcoma cells leads to poor prognosis. We plan to identify the key molecules that are involved in cell dedifferentiation and explore how they promote the pulmonary metastasis of osteosarcoma cells. We performed a sphere formation assay and confirmed that the spheroid cells could be redifferentiated into osteoblasts, adipocytes, and chondrocytes in specific medium, and the stem cell-like markers Stro-1 and CD117 were detected on the cell surface, which indicated that the spheroid cells were dedifferentiated cells. Thrombospondin 1 (THBS1) and ITGAs were identified as the key molecules in dedifferentiation through mRNA-seq and analysis, and osteosarcoma patients with higher THBS1 expression had a worse prognosis than those with lower THBS1 expression. THBS1 promotes the accumulation of ITGA1 and ITGA6 on the cell membrane in the early phase of dedifferentiation, thereby increasing the phosphorylation of FAK, RasGRF1, and MLC2 in the cytoplasm and promoting cytoskeleton remodeling. Our results suggest that THBS1 promotes cell dedifferentiation and pulmonary metastasis by promoting cytoskeletal remodeling and that ITGA1 and ITGA6 play important roles in mediating extracellular to intracellular signals; this mediating effect takes place mainly in the early phase of dedifferentiation.
Journal Article
Integrin α6/Akt/Erk signaling is essential for human breast cancer resistance to radiotherapy
Integrin α6 (ITGA6), a transmembrane glycoprotein adhesion receptor protein, is widely upregulated in many types of tumors and promotes migration and invasion in cancer cells. However, the role that the ITGA6-associated signaling network plays in radiosensitivity in breast cancer has not been described. The expression of ITGA6 was examined in human breast cancer and normal breast cell lines using western blot analysis. We also explored the role of ITGA6 in the regulation of radiation sensitivity in breast cancer using the colony formation assays, cell cycle analyses, apoptosis assays and immunofluorescence analyses. The results showed that the protein and mRNA expression levels of ITGA6 was higher in breast cancer cells than in normal cells. ITGA6 protectived responses to radiotherapy in breast cancer cells by altering cell apoptosis, DNA damage repair and cell-cycle regulation. Furthermore, ITGA6 enhanced radiation resistance via PI3K/Akt and MEK/Erk signaling. In addition, overexpressing ITGA6 promoted radiation resistance in cells, and this effect was neutralized by the PI3K inhibitor LY294002 and MEK inhibitor U0126. Taken together, these findings indicate that ITGA6 might be involved in a mechanism that underlies radiation resistance and that ITGA6 could be a potential target for therapies aimed at overcoming radiation resistance in breast cancer.
Journal Article
Downregulation of ITGA6 confers to the invasion of multiple myeloma and promotes progression to plasma cell leukaemia
2021
Background
Secondary plasma cell leukaemia (sPCL) is an aggressive form of multiple myeloma (MM), but the mechanism underlying MM progresses into PCL remains unknown.
Methods
Gene expression profiling of MM patients and PCL patients was analysed to identify the molecular differences between the two diseases. Cox survival regression and Kaplan–Meier analysis were performed to illustrate the impact of integrin subunit alpha 6 (ITGA6) on prognosis of MM. Invasion assays were performed to assess whether ITGA6 regulated the progression of MM to PCL.
Results
Gene expression profiling analyses showed that cell metastasis pathways were enriched in PCL and ITGA6 was differentially expressed between PCL and MM. ITGA6 expression was an independent prognostic factor for event-free survival (EFS) and overall survival (OS) of MM patients. Moreover, the stratification ability of the International Staging System (ISS) of MM was improved when including ITGA6 expression. Functional studies uncovered that increased ITGA6 reduced the myeloma cell invasion. Additionally, low expression of ITGA6 resulted from epigenetic downregulating of its anti-sense non-coding RNA, ITGA6-AS1.
Conclusion
Our data reveal that ITGA6 gradually decreases during plasma cell dyscrasias progression and low expression of ITGA6 contributes to myeloma metastasis. Moreover, ITGA6 abundance might help develop MM prognostic stratification.
Journal Article