Poor Prognosis In Breast Cancer Research Articles

WWOX binds MERIT40 and modulates its function in homologous recombination, implications in breast cancer

The tumor suppressor gene WWOX is localized in an unstable chromosomal region and its expression is decreased or absent in several types of cancer. A low expression of WWOX is associated with a poor prognosis in breast cancer (BC). It has recently been shown that WWOX contributes to genome stability through its role in the DNA damage response (DDR). In breast cancer cells, WWOX inhibits homologous recombination (HR), and thus promotes the repair of DNA double-stranded breaks (DSBs) by non-homologous end joining (NHEJ). The fine-tuning modulation of HR activity is crucial. Its under or overstimulation inducing genome alterations that can induce cancer. MERIT40 is a positive regulator of the DDR. This protein is indispensable for the function of the multi-protein complex BRCA1-A, which suppresses excessive HR activity. MERIT40 also recruits Tankyrase, a positive regulator of HR, to the DSBs to stimulate DNA repair. Here, we identified MERIT40 as a new molecular partner of WWOX. We demonstrated that WWOX inhibited excessive HR activity induced by overexpression of MERIT40. We showed that WWOX impaired the MERIT40-Tankyrase interaction preventing the role of the complex on DSBs. Furthermore, we found that MERIT40 is overexpressed in BC and that this overexpression is associated to a poor prognosis. These results strongly suggest that WWOX, through its interaction with MERIT40, prevents the deleterious impact of excessive HR on BC development by inhibiting MERIT40-Tankyrase association. This inhibitory effect of WWOX would oppose MERIT40-dependent BC development.

LncRNA H19 Regulates Breast Cancer DNA Damage Response and Sensitivity to PARP Inhibitors via Binding to ILF2.

Although DNA damage repair plays a critical role in cancer chemotherapy, the function of lncRNAs in this process remains largely unclear. In this study, in silico screening identified H19 as an lncRNA that potentially plays a role in DNA damage response and sensitivity to PARP inhibitors. Increased expression of H19 is correlated with disease progression and with a poor prognosis in breast cancer. In breast cancer cells, forced expression of H19 promotes DNA damage repair and resistance to PARP inhibition, whereas H19 depletion diminishes DNA damage repair and increases sensitivity to PARP inhibitors. H19 exerted its functional roles via direct interaction with ILF2 in the cell nucleus. H19 and ILF2 increased BRCA1 stability via the ubiquitin-proteasome proteolytic pathway via the H19- and ILF2-regulated BRCA1 ubiquitin ligases HUWE1 and UBE2T. In summary, this study has identified a novel mechanism to promote BRCA1-deficiency in breast cancer cells. Therefore, targeting the H19/ILF2/BRCA1 axis might modulate therapeutic approaches in breast cancer.

Association of hsa-miR-5571-5p Expression with Clinicopathological Factors besides Identification of Its Hub Target Genes and Key Pathway in Breast Cancer.

miRNAs are small non-coding RNAs; regulate gene expression using RNA degradation or translation repression. Dysregulation of miRNAs is involved in the initiation and progression of many cancers. We aimed to determine the relationship between miR-5571-5p expression and clinical factors and regulatory mechanisms in breast cancer. Histopathologic sections approximately with 25 microns thick from FFPE tissues were achievement of Al-Zahra Hospital (Isfahan, Iran) in 2020-2021 years by Pathologist. miR-5571-5p expression, determined using real-time PCR. For miRNA target genes prediction, integrated miRNA target prediction tools, were used. Gene ontology and KEGG pathway analysis were accomplished to identify the biological function. A PPI network was constructed to display key target genes. For hub genes validation, GEPIA databases were used. miR-5571-5p was upregulated in breast tumor tissues, and its increase was significantly related to a poor prognosis in breast cancer (P<0.0001). At first, 324 target genes were predicted, and then 110 genes with a decrease in expression were selected. GO analysis showed that genes were mainly enriched in the regulation of the ERBB2 and EGFR signaling pathway. KEGG pathway analysis suggested that downregulated genes were enriched in glioma, the ErbB signaling pathway, and breast cancer. Finally, the ten hub genes (EGF, PIK3R1, SOS1, PTEN, SHC1, CBLB, LIFR, LEP, PDE1C, and NT5C2) were detected from the PPI network. miR-5571-5p up-regulation is associated with breast cancer progression and worse survival. The current study identified ten genes associated with breast cancer, which might help to provide candidate targets for the treatment.

A ceRNA network-mediated over-expression of cuproptosis-related gene SLC31A1 correlates with poor prognosis and positive immune infiltration in breast cancer.

Solute carrier family 31 member 1(SLC31A1) has been reported as the copper importer, and was identified to be involved in the process of "cuproptosis". However, the mechanism of SLC31A1 in breast cancer remains unclear. We examined the expression of SLC31A1 mRNA in breast cancer tissues and cell lines using Real-time PCR. The data for this study were obtained from The Cancer Genome Atlas (TCGA) database and analyzed via R 3.6.3. TIMER, UALCAN, GEPIA2, STRING, Metascape, Kaplan-Meier Plotter, starBase and miRNet websites were used for a comprehensive analysis of SLC31A1. Our study suggested that SLC31A1 mRNA was over-expressed in breast tumor tissue and breast cancer cell lines, and which was closely related to poor relapse-free survival (RFS) and distant metastasis-free survival (DMFS). In addition, we constructed a co-expression network of SLC31A1. Functional enrichment analysis indicated that they were mainly involved in copper ion transport. Interestingly, SLC31A1 expression was positively associated with all m6A-related genes, especially with YTHDF3 (r = 0.479). Importantly, the LINC00511/miR-29c-3p/SLC31A1 axis was identified as the most potential pathway promoting breast cancer progress by affecting copper transport. Furthermore, the expression level of SLC31A1 in breast cancer was positively correlated with tumor immune cell infiltration, immune cell biomarkers and cancer-associated fibroblast (CAF). Up-regulation of SLC31A1 expression and regulation of copper ion transport mediated by LINC00511-miR-29-3p axis is related to poor prognosis and positively correlated with tumor immune infiltration in breast cancer.

Global longitudinal strain at 3 months after therapy can predict late cardiotoxicity in breast cancer.

Cancer therapy-related cardiovascular toxicity (CTR-CVT) is a major contributor to poor prognosis in breast cancer (BC) patients undergoing chemotherapy. Left ventricular global longitudinal strain (LV GLS) has predictive value for CTR-CVT, while few researchers take into account late-onset CTR-CVT. This study sought to provide a guide for the prediction of late-onset CTR-CVT in primary BC over the 2 years follow-up via strain and contrast-enhanced echocardiography. Anthracycline and anthracycline + targeted medication groups were created from 111 patients with stage I-III primary BC who were prospectively included. The left ventricular diastolic function, LV global long-axis strain (GLS); left ventricular ejection fraction by contrast-enhanced echocardiography (c-LVEF), and electrocardiograms were collected at baseline, 3, 6, 12, and 24 months after the start of cancer treatment. The high-sensitivity troponin-T and NT-pro BNP at baseline and 3 months after chemotherapy were measured. (1) LV GLS decreased in BC patients over time. (2) After 12 months' follow-up, the LV GLS in the anthracycline+ targeted group was lower than in the anthracycline group. After 24 months' follow-up, the GLS and c-LVEF in the anthracycline + targeted group declined while the E/e' increased. (3) Decreased LVEF (56%) and arrhythmia (38%) are the common causes of CTR-CVT. Lower LVEF was a major factor in late-onset CTR-CVT. (4) Combination of LV GLS and c-LVEF at 3 months were used as predictors for CTR-CVT and exhibited a higher AUC than either one alone (AUC = 0.929, 95% CI: 0.863-0.970). LV GLS at 3 months can predict the late-onset CTR-CVT (AUC = 0.745, p < 0.001), and the cut-off is 20.32%. As time went on, the systolic and diastolic dysfunction of BC patients get worsened. The combination of LV GLS and c-LVEF is better in the prediction of CTR-CVT. Only the LV GLS at 3 months can predict the late-onset CTR-CVT.

The role of TSC2 in breast cancer: a literature review.

TSC2 is a tumor suppressor gene as well as a disease-causing gene for autosomal dominant disorder tuberous sclerosis complex (TSC). Research has found that some tumor tissues have lower TSC2 expression levels than normal tissues. Furthermore, low expression of TSC2 is associated with poor prognosis in breast cancer. TSC2 acts as a convergence point of a complex network of signaling pathways and receives signals from the PI3K, AMPK, MAPK, and WNT pathways. It also regulates cellular metabolism and autophagy through inhibition of a mechanistic target of rapamycin complex, which are processes relevant to the progression, treatment, and prognosis of breast cancer. In-depth study of TSC2 functions provides significant guidance for clinical applications in breast cancer, including improving the treatment efficacy, overcoming drug resistance, and predicting prognosis. In this review, protein structure and biological functions of TSC2 were described and recent advances in TSC2 research in different molecular subtypes of breast cancer were summarized.

FOXD1 is associated with poor outcome and maintains tumor-promoting enhancer-gene programs in basal-like breast cancer.

Breast cancer biology varies markedly among patients. Basal-like breast cancer is one of the most challenging subtypes to treat because it lacks effective therapeutic targets. Despite numerous studies on potential targetable molecules in this subtype, few targets have shown promise. However, the present study revealed that FOXD1, a transcription factor that functions in both normal development and malignancy, is associated with poor prognosis in basal-like breast cancer. We analyzed publicly available RNA sequencing data and conducted FOXD1-knockdown experiments, finding that FOXD1 maintains gene expression programs that contribute to tumor progression. We first conducted survival analysis of patients grouped via a Gaussian mixture model based on gene expression in basal-like tumors, finding that FOXD1 is a prognostic factor specific to this subtype. Then, our RNA sequencing and chromatin immunoprecipitation sequencing experiments using the basal-like breast cancer cell lines BT549 and Hs578T with FOXD1 knockdown revealed that FOXD1 regulates enhancer-gene programs related to tumor progression. These findings suggest that FOXD1 plays an important role in basal-like breast cancer progression and may represent a promising therapeutic target.

Hydrogen Peroxide Induces α-Tubulin Detyrosination and Acetylation and Impacts Breast Cancer Metastatic Phenotypes.

Levels of hydrogen peroxide are highly elevated in the breast tumor microenvironment compared to normal tissue. Production of hydrogen peroxide is implicated in the mechanism of action of many anticancer therapies. Several lines of evidence suggest hydrogen peroxide mediates breast carcinogenesis and metastasis, though the molecular mechanism remains poorly understood. This study elucidates the effects of exposure to elevated hydrogen peroxide on non-tumorigenic MCF10A mammary epithelial cells, tumorigenic MCF7 cells, and metastatic MDA-MB-231 breast cancer cells. Hydrogen peroxide treatment resulted in a dose- and time-dependent induction of two α-tubulin post-translational modifications-de-tyrosination and acetylation-both of which are markers of poor patient prognosis in breast cancer. Hydrogen peroxide induced the formation of tubulin-based microtentacles in MCF10A and MDA-MB-231 cells, which were enriched in detyrosinated and acetylated α-tubulin. However, the hydrogen peroxide-induced microtentacles did not functionally promote metastatic phenotypes of cellular reattachment and homotypic cell clustering. These data establish for the first time that microtentacle formation can be separated from the functions to promote reattachment and clustering, which indicates that there are functional steps that remain to be identified. Moreover, signals in the primary tumor microenvironment may modulate α-tubulin post-translational modifications and induce microtentacles; however, the functional consequences appear to be context-dependent.

Oncogenic roles of GPR176 in breast cancer: a potential marker of aggressiveness and a potential target of gene therapy.

Belonging to the G-protein coupled receptor 1 family, G protein-coupled receptor 176 (GPR176) is associated with the Gz/Gx G-protein subclass and is capable of decreasing cAMP production. GPR176 expression was detected by qRT-PCR, bioinformatics analysis, Western blot and immunohistochemistry, and compared with clinicopathological characteristics of breast cancer. GPR176-related genes and pathways were subjected to bioinformatic analysis. We also explored the effects of GPR176 on the phenotypes of breast cancer cells. Lower expression of GPR176 mRNA was seen in breast cancer than in normal tissues, but the opposite pattern was found for its protein (p < 0.05). GPR176 mRNA was associated with female sex, low T staging, non-Her-2+ subtypes, non-mutant p53 status in breast cancer (p < 0.05). GPR176 methylation was negatively correlated with its mRNA level and T staging in breast cancer, and was higher in breastcancer than normal tissues (p < 0.05). GPR176 protein expression was positively correlated with older age, small tumor size, and non-luminal-B subtype of breast cancers (p < 0.05). The differential genes of GPR176 were involved in receptor-ligand interaction, RNA maturation, and so forth (p < 0.05). GPR176-related genes were categorized into cell mobility, membrane structure, and so on (p < 0.05). GPR176 knockdown weakened the proliferation, glucose catabolism, anti-apoptosis, anti-pyroptosis, migration, invasion, and epithelial-mesenchymal transition of breast cancer cells. These results indicate that GPR176 might be involved in the tumorigenesis and subsequent progression of breast cancer by deteriorating aggressive phenotypes. It might be utilized as a potential biomarker to indicate the aggressive behaviors and poor prognosis of breast cancer and a potential target of genetic therapy.

Pro- and anti-tumour activities of CD146/MCAM in breast cancer result from its heterogeneous expression and association with epithelial to mesenchymal transition.

CD146, also known as melanoma cell adhesion molecule (MCAM), is expressed in numerous cancers and has been implicated in the regulation of metastasis. We show that CD146 negatively regulates transendothelial migration (TEM) in breast cancer. This inhibitory activity is reflected by a reduction in MCAM gene expression and increased promoter methylation in tumour tissue compared to normal breast tissue. However, increased CD146/MCAM expression is associated with poor prognosis in breast cancer, a characteristic that is difficult to reconcile with inhibition of TEM by CD146 and its epigenetic silencing. Single cell transcriptome data revealed MCAM expression in multiple cell types, including the malignant cells, tumour vasculature and normal epithelium. MCAM expressing malignant cells were in the minority and expression was associated with epithelial to mesenchymal transition (EMT). Furthermore, gene expression signatures defining invasiveness and a stem cell-like phenotype were most strongly associated with mesenchymal-like tumour cells with low levels of MCAM mRNA, likely to represent a hybrid epithelial/mesenchymal (E/M) state. Our results show that high levels of MCAM gene expression are associated with poor prognosis in breast cancer because they reflect tumour vascularisation and high levels of EMT. We suggest that high levels of mesenchymal-like malignant cells reflect large populations of hybrid E/M cells and that low CD146 expression on these hybrid cells is permissive for TEM, aiding metastasis.

Flavonoids as Strong Inhibitors of MAPK3: A Computational Drug Discovery Approach.

Mitogen-activated protein kinase 3 (MAPK3) mediates the onset, progression, metastasis, drug resistance, and poor prognosis in various malignancies, including glioma, liver, ovarian, thyroid, lung, breast, gastric, and oral cancers. Negative regulation of MAPK3 expression using miRNAs has led to therapeutic effects in cancer. The present study performed molecular docking and dynamics simulation to identify potential MAPK3 inhibitors from natural flavonoids, possibly leading to drug development in cancer therapy. A computational drug discovery approach was performed using the AutoDock tool to identify potential MAPK3 inhibitors from 46 plant-based flavonoids. A cross-validation study was executed using the Schrödinger Maestro docking tool. Molecular dynamics (MD) was executed to evaluate the stability of docked poses between the top-ranked compounds and the MAPK3 catalytic domain. Interactions among the most potent MAPK3 inhibitors and residues within the receptor's active site were studied using the BIOVIA Discovery Studio Visualizer before and after 100 ns MD simulations. Kaempferol 3-rutinoside-4'-glucoside, kaempferol 3-rutinoside-7-sophoroside, rutin, and vicenin-2 exhibited a magnificent binding affinity to the receptor's active site. In addition, the stability of the docked poses of these compounds seemed to be stable after ∼45 ns computer simulations. The present study suggests that kaempferol 3-rutinoside-4'-glucoside, kaempferol 3-rutinoside-7-sophoroside, rutin, and vicenin-2 could strongly bind to the MAPK3 catalytic site and could be assigned as a potent inhibitor for MAPK3. These findings may be helpful in the treatment of various cancers. However, further validation experiments are needed.

CD146 as a prognostic marker in breast cancer: A meta-analysis.

CD146, a cell adhesion molecule, was first discovered in melanoma. Since then, it has been established as a promoter of tumor progression and metastasis. Many recent clinical studies have associated CD146 overexpression with poor prognosis in various cancers. However, clinical relevance of CD146 in prognosis of breast cancer has been poorly studied. We performed meta-analysis of data of all clinical studies associated with the prognostic value of CD146 expression in breast cancer. Relevant studies were retrieved from PubMed database as per the inclusion and exclusion criteria, data were extracted independently and carefully by two reviewers with the help of standardized form, and meta-analysis was performed to correlate CD146 expression with molecular subtypes, lymph node metastasis, and overall survival in breast cancer. Our findings suggest that CD146 expression is predominantly found in triple-negative breast cancer subtype (pooled odds ratio = 2.98, 95% confidence interval [CI] =2.19-4.05, P < .00001) and breast tumors overexpressing CD146 have a higher risk of lymph node metastasis (pooled relative risk = 1.64, 95% CI = 1.44-1.87, P < .00001). Furthermore, high expression of CD146 was associated with poor prognosis in breast cancer (pooled hazard ratio = 1.51, 95% CI = 1.21-1.87, P = .0002). Overall results suggested that CD146 may be a potential prognostic marker to predict metastatic potential and disease outcomes in breast cancer and can be used as a therapeutic target.

Annexin-A5 and annexin-A6 silencing prevents metastasis of breast cancer cells in zebrafish.

During tumor invasion and metastasis processes, cancer cells are exposed to major compressive and shearing forces, due to their migration through extracellular matrix, dense cell areas and complex fluids, which may lead to numerous plasma membrane damages RESULTS: : Cancer cells may survive to these mechanical stresses thanks to an efficient membrane repair machinery. Consequently, this machinery may constitute a relevant target to inhibit cancer cell dissemination. We show here that annexin-A5 (ANXA5) and ANXA6 participate in membrane repair of MDA-MB-231 cells, a highly invasive triple-negative breast cancer cell line. These crucial components of the membrane repair machinery are substantially expressed in breast cancer cells in correlation with their invasive properties. In addition, high expression of ANXA5 and ANXA6 predict poor prognosis in high-grade lung, gastric and breast cancers. In zebrafish, the genetic inhibition of ANXA5 and ANXA6 leads to drastic reduction of tumor cell dissemination. We conclude that the inhibition of ANXA5 and ANXA6 prevents membrane repair in cancer cells, which are thus unable to survive to membrane damage during metastasis. This result opens a new therapeutic strategy based on targeting membrane repair machinery to inhibit tumor invasion and metastasis. This article is protected by copyright. All rights reserved.

Abstract 6251: High expression level of GSK3β in basal triple negative breast cancer: Effects of the HDAC inhibitor, vorinostat

Abstract High expression levels of glycogen synthases kinase 3 beta (GSK3β) have been correlated with poor prognosis in triple negative breast cancer (TNBC) patients. GSK3β is a multifaceted kinase and is a key regulator of a number of cellular processes. It is known to function as a positive regulator of epithelial-mesenchymal transition (EMT). Usually, cells that undergo EMT are known to acquire stem cell properties and these cells have properties that are known to be resistant to chemotherapies. Inhibition of GSK3β has been shown to decrease markers of EMT and reduce cancer stem cells. High levels of GSK3β were found in the basal-2 subtype of triple negative breast cancer cells, HCC1806. Histone deacetylases (HDACs) are expressed at high levels in some cancers, including TNBC. In this study, vorinostat, a histone deacetylase inhibitor, was shown to down regulate GSK3 expression in HCC1806 cells at both the gene and protein level using qPCR and western blots. Furthermore, cancer stem cells (CSC) cell markers CD44/CD24 using flow cytometry and immunostaining were significantly decreased. Previous studies published from our laboratory have shown vorinostat’s ability to decrease TNBC cells invasion compacity, as well as cell growth. This study suggests that targeting GSK3β may be a potential therapeutic target for certain subtypes of TNBC. Triple negative breast cancer remains one of the most aggressive breast cancers, often having a high mortality rate in younger women. Citation Format: Beverly D. Lyn-Cook, Fatemeh Nouri Emamzaden, Beverly Word, George Hammons. High expression level of GSK3β in basal triple negative breast cancer: Effects of the HDAC inhibitor, vorinostat [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6251.

Abstract 5563: Androgen receptor (AR) is frequently found in human cancers and inversely linked to patient outcome in breast and renal cell carcinomas

Abstract Background: Androgen receptor (AR) is a nuclear transcription regulator which mediates the growths stimulating effect of androgens. Inhibition of AR signaling is the most important first line therapy in prostate cancer. Clinical trials are ongoing for molecularly defined subsets of breast cancers expressing AR. In surgical pathology, AR immunohistochemistry is used as a marker for prostate cancer. Design: To comprehensively determine AR expression in normal and neoplastic tissues, a tissue microarray containing 18,234 samples from 141 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. Results: AR positivity was found in 116 of 141 tumor categories, and 66 of these tumor categories contained at least one case with strong AR staining. AR positivity was most seen in different categories of prostate cancer (87.8-100%), various subtypes of breast cancer (34.3-94.9%) and ovarian cancers (48.7-97.1%), in endometrial cancers (53-61.1%), salivary duct carcinomas (70%), teratomas (60%), renal cell carcinomas (41.8-62.7%), urinary bladder cancers (43.2-48.7%), granular cell tumors (40.7%), leiomyosarcomas (33.3%), gastrointestinal stroma tumors (31.1%) and urothelial carcinomas of the kidney pelvis (30.4%). Seventy-seven additional tumor types showed AR expression in up to 30% of the analyzed samples, but AR expression was typically only weak in these tumors. Among 1,430 evaluable invasive breast carcinomas of no special type (NST), absent or low AR immunostaining was significantly linked to high BRE grade (p&amp;lt;0.0001), advanced pT stage (p&amp;lt;0.0001), presence of nodal and distant metastasis (p&amp;lt;0.0001 each), HER2 overexpression (p=0.005), reduced estrogen and progesterone receptor expression (p&amp;lt;0.0001 each), triple negative status (p&amp;lt;0.0001) and shortened patient survival (p=0.0024). Among 1,149 clear cell renal cell cancers (RCC), low AR immunostaining was linked to high ISUP, Fuhrman and Thoenes grades (p&amp;lt;0.0001 each), high UICC and pT stage (p&amp;lt;0.0001 each), presence of distant metastases (p=0.0075), and reduced time to recurrence (p=0.0007), overall survival (p=0.0097) and tumor-specific survival (p=0.0129). In 297 papillary RCC, low AR staining was associated with high ISUP grade (p=0.0179), advanced pT stage (p=0.0055) and nodal metastasis (p=0.0044). Low AR expression was linked to invasive growth (p&amp;lt;0.0001) and nodal metastasis in urothelial carcinoma (p=0.0052). Conclusion: The results of our study demonstrate AR expression in a wide range of cancers. AR expression occurs most frequent in cancers of the prostate, breast, and ovary, but can be found in many types of non-prostate and non-gynecological neoplasms. The poor prognosis of breast and kidney cancers with reduced AR expression argues against a tumor promoting role of AR in these tumor types. Citation Format: Florian Viehweger, David Dum, Anne Menz, Ria Uhlig, Andrea Hinsch, Doris Höflmayer, Tim Mandelkow, Christoph Fraune, Christian Bernreuther, Patrick Lebok, Sören Weidemann, Guido Sauter, Maximilian Lennartz, Frank Jacobsen, Till S. Clauditz, Till Krech, Andreas H. Marx, Ronald Simon, Stefan Steurer, Eike Burandt, Sarah Minner. Androgen receptor (AR) is frequently found in human cancers and inversely linked to patient outcome in breast and renal cell carcinomas. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5563.

Abstract 1281: Oncoprotein YB-1 modulation of Lyn-MAPK-NF-kB pathway, a potential therapeutic strategy combined with sorafenib for advanced stage HCC

Abstract The Y-Box Binding protein 1 (YB-1) is a 324 amino acid-long member of the Cold Shock Domain (CSD) protein superfamily. YB-1 interacts with micro RNAs and non-coding RNAs in the cytoplasm, acting as a regulator of mRNA translation. YB-1 translocation into the nucleus is circadian clock-dependent and leads to the upregulation of cyclin gene expression, among others. Another mechanism of nuclear translocation of YB-1 is mediated by phosphorylation of the Ser 102 residue in the CSD. The YB-1 oncoprotein acts as a transcription factor when bound to DNA, modulating the transcription of genes that regulate biological processes such as Multidrug Resistance Mutation 1 (MDR1). YB-1 is linked to poor prognosis in breast, prostate, and liver cancer. Despite advances in biomedicine, the incidence and mortality of hepatocellular carcinoma (HCC) remain high. Sorafenib, a tyrosine kinase Inhibitor (TKI), is the first-line treatment for advanced HCC. Sorafenib also inhibits downstream activation of NF-kB by inhibition of Lyn phosphorylation (Y397). However, it was observed in many patients that its sorafenib’s effectiveness is hampered by drug resistance, but the mechanism is still unclear. We have found that SK-HEP-1 HCC cells transfected with a YB-X-1 overexpression plasmid subsequently developed into a stable YB-1 overexpression cell line (SK-HEP-1+YB-1) displayed increased invasion, migration, proliferation, and colony formation property as compared to the vector control (SKHEP1+Vec). The SK-HEP-1+YB-1 cell line also showed increased IC50 for sorafenib and elevated phosphorylation of Lyn (Y397) and further activated NF-kB (S165/S176) phosphorylation. This indicates YB-1 may cause increased Sorafenib resistance in HCC by activating tyrosine kinases (TK), such as lyn, and simultaneous activation of NF-kB. The combination of YB-1 inhibition and sorafenib might provide a novel therapeutic strategy and improve the survival of patients with advanced-stage HCC. Citation Format: Ana G. Ayala Pazzi, Omar Karkoutly, Kristopher Ezell, Samantha Lopez, Kyle D. Doxtater, Elias George, Vijian Dhevan, Manish K. Tripathi. Oncoprotein YB-1 modulation of Lyn-MAPK-NF-kB pathway, a potential therapeutic strategy combined with sorafenib for advanced stage HCC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1281.

GATA-3 expression in breast cancer is related to intratumoral M2 macrophage infiltration and tumor differentiation.

Accumulating evidence indicates that tumor-associated macrophages promote tumor progression and that high macrophage infiltration is correlated with advanced tumor stages and poor prognosis in breast cancer. GATA binding protein 3 (GATA-3) is a differentiation marker related to differentiated states in breast cancer. In this study, we explore how the extent of MI relates to GATA-3 expression, hormonal status, and the differentiation grade of breast cancer. To examine breast cancer in early development, we selected 83 patients that were treated with radical breast-conserving surgery (R0), without lymph node metastases (N0) or distant metastases (M0), with and without postoperative radiotherapy. Immunostaining of M2-macrophage-specific antigen CD163 was used to detect tumor-associated macrophages, and macrophage infiltration was estimated semi-quantitatively into no/low, moderate, and high infiltration. The macrophage infiltration was compared to GATA-3, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2), and Ki-67 expression in cancer cells. GATA-3 expression is associated with ER and PR expression but inversely correlated to macrophage infiltration and Nottingham histologic grade. High macrophage infiltration in advanced tumor grade was associated with low GATA-3 expression. The disease-free survival is inversely related to Nottingham histologic grade in patients having tumors with no/low macrophage infiltration, a difference that is not found in patients with moderate/high macrophage infiltration. These findings indicate that macrophage infiltration might impact the differentiation, malignant behavior, and prognosis of breast cancer, regardless of the morphological and hormonal states of the cancer cells in the primary tumor.

S1P1 Threonine 236 Phosphorylation Mediates the Invasiveness of Triple-Negative Breast Cancer and Sensitivity to FTY720.

Hyperactive sphingosine 1-phosphate (S1P) signaling is associated with a poor prognosis of triple-negative breast cancer (TNBC). Despite recent evidence that links the S1P receptor 1 (S1P1) to TNBC cell survival, its role in TNBC invasion and the underlying mechanisms remain elusive. Combining analyses of human TNBC cells with zebrafish xenografts, we found that phosphorylation of S1P receptor 1 (S1P1) at threonine 236 (T236) is critical for TNBC dissemination. Compared to luminal breast cancer cells, TNBC cells exhibit a significant increase of phospho-S1P1 T236 but not the total S1P1 levels. Misexpression of phosphorylation-defective S1P1 T236A (alanine) decreases TNBC cell migration in vitro and disease invasion in zebrafish xenografts. Pharmacologic disruption of S1P1 T236 phosphorylation, using either a pan-AKT inhibitor (MK2206) or an S1P1 functional antagonist (FTY720, an FDA-approved drug for treating multiple sclerosis), suppresses TNBC cell migration in vitro and tumor invasion in vivo. Finally, we show that human TNBC cells with AKT activation and elevated phospho-S1P1 T236 are sensitive to FTY720-induced cytotoxic effects. These findings indicate that the AKT-enhanced phosphorylation of S1P1 T236 mediates much of the TNBC invasiveness, providing a potential biomarker to select TNBC patients for the clinical application of FTY720.

TXNIP loss expands Myc-dependent transcriptional programs by increasing Myc genomic binding

The c-Myc protooncogene places a demand on glucose uptake to drive glucose-dependent biosynthetic pathways. To meet this demand, c-Myc protein (Myc henceforth) drives the expression of glucose transporters, glycolytic enzymes, and represses the expression of thioredoxin interacting protein (TXNIP), which is a potent negative regulator of glucose uptake. A Mychigh/TXNIPlow gene signature is clinically significant as it correlates with poor clinical prognosis in triple-negative breast cancer (TNBC) but not in other subtypes of breast cancer, suggesting a functional relationship between Myc and TXNIP. To better understand how TXNIP contributes to the aggressive behavior of TNBC, we generated TXNIP null MDA-MB-231 (231:TKO) cells for our study. We show that TXNIP loss drives a transcriptional program that resembles those driven by Myc and increases global Myc genome occupancy. TXNIP loss allows Myc to invade the promoters and enhancers of target genes that are potentially relevant to cell transformation. Together, these findings suggest that TXNIP is a broad repressor of Myc genomic binding. The increase in Myc genomic binding in the 231:TKO cells expands the Myc-dependent transcriptome we identified in parental MDA-MB-231 cells. This expansion of Myc-dependent transcription following TXNIP loss occurs without an apparent increase in Myc's intrinsic capacity to activate transcription and without increasing Myc levels. Together, our findings suggest that TXNIP loss mimics Myc overexpression, connecting Myc genomic binding and transcriptional programs to the nutrient and progrowth signals that control TXNIP expression.

The Heparan Sulfate Proteoglycan Syndecan-1 Triggers Breast Cancer Cell-Induced Coagulability by Induced Expression of Tissue Factor.

Syndecan-1 (Sdc-1) upregulation is associated with poor prognosis in breast cancer. Sdc-1 knockdown results in reduced angiogenesis and the dysregulation of tissue factor (TF) pathway constituents. Here, we evaluate the regulatory mechanisms and functional consequences of the Sdc-1/TF-axis using Sdc-1 knockdown and overexpression approaches in MCF-7 and MDA-MB-231 breast cancer cells. Gene expression was analyzed by means of qPCR. Thrombin generation and cell migration were detected. Cell-cycle progression and apoptosis were investigated using flow cytometry. In MDA-MB-231 cells, IL6, IL8, VEGF, and IGFR-dependent signaling affected TF pathway expression depending on Sdc-1. Notably, Sdc-1 depletion and TF pathway inhibitor (TFPI) synergistically affected PTEN, MAPK, and STAT3 signaling. At the functional level, the antiproliferative and pro-apoptotic effects of TFPI depended on Sdc-1, whereas Sdc-1's modulation of cell motility was not affected by TFPI. Sdc-1 overexpression in MCF-7 and MDA-MB-231 cells led to increased TF expression, inducing a procoagulative phenotype, as indicated by the activation of human platelets and increased thrombin formation. A novel understanding of the functional interplay between Sdc-1 and the TF pathway may be compatible with the classical co-receptor role of Sdc-1 in cytokine signaling. This opens up the possibility of a new functional understanding, with Sdc-1 fostering coagulation and platelet communication as the key to the hematogenous metastatic spread of breast cancer cells.