GATA3 Truncation Mutants Alter EMT Related Gene Expression via Partial Motif Recognition in Luminal Breast Cancer Cells

Investigating the Role of Osteopontin (OPN) in the Progression of Breast, Prostate, Renal and Skin Cancers

Background/Objectives: Cancer is caused by disruptions in the homeostatic state of normal cells, which results in dysregulation of the cell cycle, and uncontrolled growth and proliferation in affected cells to form tumors. Successful development of tumorous cells proceeds through the activation of pathways promoting cell development and functionality, as well as the suppression of immune signaling pathways; thereby providing these cells with proliferative advantages, which subsequently metastasize into surrounding tissues. These effects are primarily caused by the upregulation of oncogenes, of which SPP1 (secreted phosphoprotein 1), a non-collagenous bone matrix protein, is one of the most well-known. Methods: In this study, we conducted a further examination of the transcriptomic expression profile of SPP1 (Osteopontin) during the progression of cancer in four human tissues, breast, prostate, renal and skin, in order to understand the circumstances conducive to its activation and dysregulation, the biological pathways and other mechanisms involved as well as differences in its splicing patterns influencing its expression and functionality. Results: A significant overexpression of SPP1, as well as a set of other highly correlated genes, was seen in most of these tissues, indicating their extensive implication in cancer. Increased expression was observed with higher tumor stages, especially in renal and skin cancer, while applying therapeutic modalities targeting these genes dampened this effect in breast, prostate and skin cancer. Pathway analyses showed gene signatures related to cell growth and development enriched in tumorigenic conditions and earlier cancer stages, while later stages of cancer showed pathways associated with weakened immune response, in all cancers studied. Moreover, the utilization of therapeutic methods showed the activation of immunogenic pathways in breast, prostate and skin cancer, thereby confirming their viability. Further analyses of differential transcript expression levels in these oncogenes showed their exonic regions to be selectively overexpressed similarly in tumorigenic samples in all cancers studied, while also displaying significant differences in exon selectivity between constituent transcripts, providing a basis for their high degree of multifunctionality in cancer. Conclusions: Overall, this study corroborates the entrenched role of SPP1 in the progression of these four types of cancer, as confirmed by its overexpression and activation of related oncogenes, their co-involvement in key cellular pathways, and predisposition to exhibit differential splicing between their transcripts, while the above effects were found to be highly inhibitable through treatment methods, thereby highlighting its promising role in therapeutic development.

The Genomic and Biologic Landscapes of Breast Cancer and Racial Differences

Breast cancer is a significant health challenge worldwide and is the most frequently diagnosed cancer among women globally. This review provides a comprehensive overview of breast cancer biology, genomics, and microbial dysbiosis, focusing on its various subtypes and racial differences. Breast cancer is primarily classified into carcinomas and sarcomas, with carcinomas constituting most cases. Epidemiology and breast cancer risk factors are important for public health intervention. Staging and grading, based on the TNM and Nottingham grading systems, respectively, are crucial to determining the clinical outcome and treatment decisions. Histopathological subtypes include in situ and invasive carcinomas, such as invasive ductal carcinoma (IDC) and invasive lobular carcinoma (ILC). The review explores molecular subtypes, including Luminal A, Luminal B, Basal-like (Triple Negative), and HER2-enriched, and delves into breast cancer's histological and molecular progression patterns. Recent research findings related to nuclear and mitochondrial genetic alterations, epigenetic reprogramming, and the role of microbiome dysbiosis in breast cancer and racial differences are also reported. The review also provides an update on breast cancer's current diagnostics and treatment modalities.

Bioinformatic and experimental analyses of GATA3 and its regulatory miRNAs in breast Cancer

BACKGROUND

GATA binding protein 3 (GATA3) is a transcription factor that plays a critical role in the differentiation and function of luminal epithelial cells in the breast. MicroRNAs (miRNAs) are small non-coding RNAs that modulate gene expression and their dysregulation has been implicated in cancer. The purpose of this study was to investigate the expression of GATA3 and its corresponding targeting miRNAs in breast cancer.

MATERIALS AND METHODS

In this study, we used bioinformatic tools, including the miRWalk database and RNA Hybrid online tool, to identify potential miRNAs that target the GATA3 mRNA. Then, we collected frozen tissue specimens from 67 breast cancer patients and 67 adjacent normal breast tissue samples and evaluated the expression levels of GATA3, hsa-miR-433-3p, and hsa-miR-144-3p using quantitative RT-PCR.

RESULTS

We found that hsa-miR-433-3p and hsa-miR-144-3p are potential miRNAs that target the GATA3 mRNA, and we found that both were significantly downregulated in breast cancer tissues relative to adjacent normal breast tissues (P < 0.0001). We also observed a significant upregulation of the GATA3 mRNA in breast cancer tissues (P < 0.0001). Additionally, we found that their dysregulation was associated with clinicopathological features such as invasive carcinoma and carcinoma in situ subtypes, tumor grade, estrogen receptor status, progesterone receptor status, and HER2 status.

CONCLUSIONS

Our study represents the first attempt to investigate the expression of GATA3 and its targeting miRNAs simultaneously in breast cancer. Our findings suggest that dysregulation of these genes may contribute to breast cancer development and progression.

GATA3 and markers of epithelial-mesenchymal transition predict long-term benefit from tamoxifen in ER-positive breast cancer

GATA binding protein 3 (GATA3) is essential for normal development of the mammary gland and associated with ER-positive breast cancer. Loss of GATA3 has been associated with epithelial-mesenchymal transition (EMT) in experimental studies. We investigated tumoral GATA3 in a cohort of postmenopausal patients with lymph-node negative breast cancer, randomized to adjuvant tamoxifen or control. Nuclear GATA3 expression was assessed with immunohistochemistry and GATA3 gene expression with Agilent microarrays. High GATA3 nuclear expression was associated with a lower rate of distant recurrence in ER-positive breast cancer (HR = 0.60, 95% CI 0.39-0.93). Low gene expression of GATA3 was associated with limited long-term benefit from adjuvant tamoxifen (interaction: p = 0.033). GATA3 gene expression was associated with the epithelial markers CDH1 (E-cadherin) and FOXA1, whereas negatively associated with several mesenchymal markers. Low expression of CDH1 was associated with marginal tamoxifen benefit (HR = 0.80 (0.43-1.49)), whereas patients with higher expression showed a significant benefit (HR = 0.33 (0.20-0.55), interaction: p = 0.029). In ER-positive breast cancer, diminished expression of GATA3 is associated with markers of EMT and poor long-term benefit from tamoxifen.

A moderate dosage of prostaglandin E2-mediated annexin A1 upregulation promotes alkali-burned corneal repair

Corneal alkali burn remains a clinical challenge in ocular emergency, necessitating the development of effective therapeutic drugs. Here, we observed the arachidonic acid metabolic disorders of corneas induced by alkali burns and aimed to explore the role of Prostaglandin E2 (PGE2), a critical metabolite of arachidonic acid, in the repair of alkali-burned corneas. We found a moderate dosage of PGE2 promoted the alkali-burned corneal epithelial repair, whereas a high dosage of PGE2 exhibited a contrary effect. This divergent effect is attributed to different dosages of PGE2 regulating ANXA1 expression differently. Mechanically, a high dosage of PGE2 induced higher GATA3 expression, followed by enhanced GATA3 binding to the ANXA1 promoter to inhibit ANXA1 expression. In contrast, a moderate dosage of PGE2 increased CREB1 phosphorylation and reduced GATA3 binding to the ANXA1 promoter, promoting ANXA1 expression. We believe PGE2 and its regulatory target ANXA1 could be potential drugs for alkali-burned corneas.

The epithelial-mesenchymal plasticity landscape: principles of design and mechanisms of regulation

Epithelial-mesenchymal plasticity (EMP) enables cells to interconvert between several states across the epithelial-mesenchymal landscape, thereby acquiring hybrid epithelial/mesenchymal phenotypic features. This plasticity is crucial for embryonic development and wound healing, but also underlies the acquisition of several malignant traits during cancer progression. Recent research using systems biology and single-cell profiling methods has provided novel insights into the main forces that shape EMP, which include the microenvironment, lineage specification and cell identity, and the genome. Additionally, key roles have emerged for hysteresis (cell memory) and cellular noise, which can drive stochastic transitions between cell states. Here, we review these forces and the distinct but interwoven layers of regulatory control that stabilize EMP states or facilitate epithelial-mesenchymal transitions (EMTs) and discuss the therapeutic potential of manipulating the EMP landscape.

P4HTM: A Novel Downstream Target of GATA3 in Breast Cancer

Breast cancer continues to be a major cause of death among women. The GATA3 gene is often overexpressed in breast cancer and is widely used to support a diagnosis. However, lower expression of GATA3 has been linked to poorer prognosis along with frequent gene mutations. Therefore, the role of GATA3 in breast cancer appears to be context specific. This study aims to identify a new downstream target of GATA3 to better understand its regulatory network. Clinical data analysis identified the prolyl 4-hydroxylase transmembrane protein (P4HTM) as one of the most highly co-expressed genes with GATA3. Immunohistochemical staining of breast tumors confirms co-expression between GATA3 and P4HTM at the protein level. Similar to GATA3, P4HTM expression levels are linked to patient prognosis, with lower levels indicating poorer survival. Genomics data found that GATA3 binds to the P4HTM locus, and that ectopic expression of GATA3 in basal breast cancer cells increases the P4HTM transcript level. These results collectively suggest that P4HTM is a novel downstream target of GATA3 in breast cancer and is involved in tumor progression.

GATA3 Exerts Distinct Transcriptional Functions to Regulate Radiation Resistance in A549 and H1299 Cells

Background

Radiation resistance of lung cancer cells is a vital factor affecting the curative effect of lung cancer. Transcription factor GATA3 is involved in cell proliferation, invasion, and migration and is significantly expressed in a variety of malignancies. However, the molecular mechanism governing GATA3 regulation in lung cancer cells' radiation resistance is unknown.

Methods

Radiation-resistant cell models (A549-RR and H1299-RR) were made using fractionated high-dose irradiation. Use clone formation, CCK-8, F-actin staining, cell cycle detection, and other experiments to verify whether the model is successfully constructed. Cells were transiently transfected with knockdown or overexpression plasmid. To explore the relationship between GATA3/H3K4me3 and target genes, we used ChIP-qPCR, ChIP-seq, and dual luciferase reporter gene experiments. Xenograft tumor models were used to evaluate the effect of GATA3 depletion on the tumorigenic behavior of lung cancer cells.

Results

We report that transcription factors GATA3 and H3K4me3 coactivate NRP1 gene transcription when A549 cells develop radiation resistance. However, the mechanism of radiation resistance in H1299 cells is that GATA3 acts as a transcription inhibitor. The decrease of GATA3 will promote the increase of NRP1 transcription, in which H3K4me3 does not play a leading role.

Conclusions

GATA3, an upstream transcriptional regulator of NRP1 gene, regulates the radioresistance of A549 and H1299 cells by opposite mechanisms, which provides a new target for radiotherapy of lung cancer.

Establishment and Analysis of an Individualized EMT-Related Gene Signature for the Prognosis of Breast Cancer in Female Patients

Background. The current high mortality rate of female breast cancer (BC) patients emphasizes the necessity of identifying powerful and reliable prognostic signatures in BC patients. Epithelial-mesenchymal transition (EMT) was reported to be associated with the development of BC. The purpose of this study was to identify prognostic biomarkers that predict overall survival (OS) in female BC patients by integrating data from TCGA database. Method. We first downloaded the dataset in TCGA and identified gene signatures by overlapping candidate genes. Differential analysis was performed to find differential EMT-related genes. Univariate regression analysis was then performed to identify candidate prognostic variables. We then developed a prognostic model by multivariate analysis to predict OS. Calibration curves, receiver operating characteristics (ROC) curves, $C$ -index, and decision curve analysis (DCA) were used to test the veracity of the prognostic model. Result. In this study, we identified and validated a prognostic model integrating age and six genes (CD44, P3H1, SDC1, COL4A1, TGFβ1, and SERPINE1). $C$ -index values for BC patients were 0.672 (95% CI 0.611–0.732) and 0.692 (95% CI 0.586–0.798) in the training cohort and test set, respectively. The calibration curve and the DCA curve show the good predictive performance of the model. Conclusion. This study offered a robust predictive model for OS prediction in female BC patients and may provide a more accurate treatment strategy and personalized therapy in the future.

A Tale of Two Cancers: A Current Concise Overview of Breast and Prostate Cancer

Cancer is a global issue, and it is expected to have a major impact on our continuing global health crisis. As populations age, we see an increased incidence in cancer rates, but considerable variation is observed in survival rates across different geographical regions and cancer types. Both breast and prostate cancer are leading causes of morbidity and mortality worldwide. Although cancer statistics indicate improvements in some areas of breast and prostate cancer prevention, diagnosis, and treatment, such statistics clearly convey the need for improvements in our understanding of the disease, risk factors, and interventions to improve life span and quality of life for all patients, and hopefully to effect a cure for people living in developed and developing countries. This concise review compiles the current information on statistics, pathophysiology, risk factors, and treatments associated with breast and prostate cancer.