Epigenetic modulations in triple-negative breast cancer: Therapeutic implications for tumor microenvironment.

Triple-negative breast cancer (TNBC) is an aggressive subtype lacking estrogen receptors, progesterone receptors and lacks HER2 overexpression. This absence of critical molecular targets poses significant challenges for conventional therapies. Immunotherapy, remarkably immune checkpoint blockade, offers promise for TNBC treatment, but its efficacy remains limited. Epigenetic dysregulation, including altered DNA methylation, histone modifications, and imbalances in regulators such as BET proteins, plays a crucial role in TNBC development and resistance to treatment. Hypermethylation of tumor suppressor gene promoters and the imbalance of histone methyltransferases such as EZH2 and histone deacetylases (HDACs) profoundly influence tumor cell proliferation, survival, and metastasis. In addition, epigenetic alterations critically shape the tumor microenvironment (TME), including immune cell composition, cytokine signaling, and immune checkpoint expression, ultimately contributing to immune evasion. Targeting these epigenetic mechanisms with specific inhibitors such as EZH2 and HDAC inhibitors in combination with immunotherapy represents a compelling strategy to remodel the TME, potentially overcoming immune evasion and enhancing therapeutic outcomes in TNBC. This review aims to comprehensively elucidate the current understanding of epigenetic modulation in TNBC, its influence on the TME, and the potential of combining epigenetic therapies with immunotherapy to overcome the challenges posed by this aggressive breast cancer subtype.

Habitual Expressive Suppression of Positive, but not Negative, Emotions Consistently Predicts Lower Well-being across Two Culturally Distinct Regions.

Habitual expressive suppression (i.e., a tendency to inhibit the outward display of one's emotions; hereafter suppression) is often conceptualized as a maladaptive emotion regulation strategy. Yet, is this equally true for suppression of positive and of negative emotions? Across three studies and seven samples (total N > 1300 people) collected in two culturally distinct regions (i.e., Taiwan and the US), we examined the separability and distinct well-being effects of suppressing positive vs. negative emotions. Results consistently showed that (a) people suppressed their positive (vs. negative) emotions less, (b) the construct of suppression of positive (vs. negative) emotions was conceptually farther away from that of suppression of emotions in general, (c) suppression of positive and of negative emotions were only moderately correlated, and (d) only suppression of positive, but not negative, emotions, predicted lower well-being. An internal meta-analysis (k = 52 effect sizes) showed that these associations were robust to the inclusion of age, gender, and region as covariates. Future research may further probe the respective links between suppression of positive and of negative emotions and well-being across more cultural regions and across the life-span.

The loss of B7-H4 expression in breast cancer cells escaping from T cell cytotoxicity contributes to epithelial-to-mesenchymal transition.

BACKGROUND: B7 homology 4 (B7-H4), a potential target for cancer therapy, has been demonstrated to inhibit T cell cytotoxicity in the early stages of breast cancer. However, B7-H4 manipulating breast tumor immune microenvironment (TIME) in the tumor progression remains unknown. METHODS: We engineered T cells with B7-H4-specific chimeric antigen receptors (CARs) and performed a T cell co-culture assay to characterize B7-H4 expression level in breast cancer cells escaping from T cell cytotoxicity. We generated B7-H4 knockout (KO) and overexpression (OE) breast cancer cells to determine the epithelial-to-mesenchymal transition (EMT) and stemness characteristics in vitro and in vivo, including tumor proliferation, migration, metastasis and chemoresistance. The Cancer Genome Atlas breast cancer database was accessed to investigate the correlation between B7-H4 expression levels and EMT characteristics in patients with breast cancer. RESULTS: Our result found that B7-H4 expression level was significantly reduced in a subset of breast cancer cells that escaped from the cytotoxicity of B7-H4 CAR-T cells. Compared with wild type cells, B7-H4 KO cells prompt EMT and stemness characteristics, including migration, invasion and metastasis, and OE cells vice versa. The increase in H3K27me3 in KO cells confirmed the epigenetic reprogramming of cancer stem cells. The IC50 of doxorubicin or oxaliplatin significantly increased in KO cells, which was in agreement with a decrease in OE cells. Moreover, a trend of downregulated B7-H4 from stage I to stage II breast cancer patients indicates that the low-expressing B7-H4 breast cancer cells escaping from TIME have spread to nearby breast lymph nodes in the cancer progression. CONCLUSIONS: Our study illuminates the novel role of renouncing B7-H4 in breast cancer cells through immune escape, which contributes to EMT processes and provides new insights for breast cancer treatments.

Believe, express, and enjoy: utility beliefs about social emotion expression consistently predict satisfactory outcomes.

The present study investigates the association between people's beliefs about emotion and their overall satisfaction with a social interaction. We focus on three specific aspects to examine this association: (a) utility beliefs-a dimension of emotion beliefs; (b) emotion expression-an emotion channel; and (c) four social emotions-anger, other-embarrassment, gratitude, and other-pride. We examine whether people's utility beliefs about expressing a social emotion can predict their evaluation of a social interaction when they express (vs. suppress) their social emotion. Results (N = 209) consistently show that when people express their social emotion, their utility beliefs positively predict their satisfaction with an event. However, when people suppress their gratitude, their utility beliefs negatively predict their satisfaction, an effect not observed in the other three emotion events. These findings corroborate the claim that emotion beliefs impact people's emotional lives. Implications for research on emotion beliefs and motivated emotion regulation are discussed.

Chemokine CCL5 immune subtypes of human liver cancer with prognostic significance.

The immunogenicity of the liver tumor microenvironment is clinically heterogeneous and mysterious. The insight into the role of immune cells including tumor-infiltrating lymphocytes (TILs) and chemokine networks, might enable optimal patient selection for immunotherapy. In this study, we aimed at characterizing the liver cancer immune subtypes linked to chemokines and associating with the patient characteristics and clinical outcomes. We analyzed the immune cells and chemokine signatures of human liver cancer using GTEx and TCGA profiling of 110 normal liver tissues and 369 liver tumor patients. We performed hierarchical clustering to the chemokine expression by applying immune cells status to categorize the CCL5-related chemokine in liver tumors. The separation was characterized by dividing the liver tumor patients into CCL5-high and low subtypes. Our results showed that the high expression of myeloid-derived suppressor cells (MDSCs) is associated with a decrease in effector T cells expressing PRF1 in liver tumor progression. Our data demonstrated that the CCL5-high subtype significantly improved OS (p = 0.0379, hazard ratio (HR) 0.67; 95 % CI 0.43, 0.98), DFI (p = 0.0104, HR 0.63; 95 % CI 0.44, 0.90), PFI (p = 0.0066, HR 0.64; 95 % CI 0.46, 0.89) and working performance status. Our findings provide a novel perspective of liver cancer chemokine subtypes linked to immune cells. The therapy that can effectively activate effector T cells and inhibit MDSCs targeting chemokine networks might support the magnitude of TILs in liver tumors. The chemokine signatures in the CCL5-subtype are a valuable resource for future research to identify clinically relevant biomarkers.

An experimental model for ovarian cancer: propagation of ovarian cancer initiating cells and generation of ovarian cancer organoids.

BACKGROUND: Ovarian cancer (OC) is the most lethal gynecological cancer due to the recurrence of drug-resistance. Cancer initiating cells (CICs) are proposed to be responsible for the aggressiveness of OC. The rarity and difficulty of in vitro long-term cultivation of CICs challenge the development of CIC-targeting therapeutics. Reprogramming cancer cells into induced cancer initiating cell (iCICs) could be an approach to solve these. Several inducible CICs have been acquired by activating the expression of stemness genes in different cancer cells. However, few reports have demonstrated the feasibility in OC. METHODS: Patients with primary OC receiving surgery were enrolled. Tumor tissue were collected, and OCT4, SOX2, and NANOG expressions were assessed by immunohistochemistry (IHC) staining to investigate the association of stemness markers with overall survival (OS). An high-grade serous ovarian cancer (HGSOC) cell line, OVCAR-3 was reprogrammed by transducing Yamanaka four factors OCT4, SOX2, KLF4 and MYC (OSKM) to establish an iOCIC model, iOVCAR-3-OSKM. CIC characteristics of iOVCAR-3-OSKM were evaluated by RT-PCR, sphere formation assay and animal experiments. Drug-resistance and migration ability were accessed by dye-efflux activity assay, MTT assay and migration assay. Gene profile was presented through RNA-sequencing. Lineage differentiation ability and organoid culture were determined by in vitro differentiation assays. RESULTS: In OC patients, the co-expression of multiple stem-related transcription factors (OCT4, SOX2, and NANOG) was associated with worse OS. iOVCAR-3-OSKM cells generated by reprogramming successfully exhibited stemness characteristics with strong sphere-forming and tumorigenesis ability. iOVCAR-3-OSKM cells also showed malignant potential with higher drug resistance to chemodrug, Paclitaxel (PTX) and migration ability. iOVCAR-3-OSKM was maintainable and expandable on feeder-dependent culture condition, it also preserved ovarian lineage differentiation abilities, which could well differentiate into OC cells with CK-7 and CA125 expressions and develop into an organoid mimic poor prognostic OC histological feature. CONCLUSIONS: The establishment of iOVCAR-3-OSKM not only allows us to fill the gap in the information on induced CICs in OC but also provides a potential strategy to develop personalized CICs and organoid models for treating OC in the near future.

Evaluation of inhibitors of intestinal UDP-glucuronosyltransferases 1A8 and 1A10 using raloxifene as a substrate in Caco-2 cells: Studies with four flavonoids of Scutellaria baicalensis.

UDP glucuronosyltransferases (UGTs) of the gastrointestinal tract play a crucial role in protection against the toxic effects of xenobiotics in the environment. UGTs such as UGT1A8 and UGT1A10 are predominantly expressed in gastrointestinal tissues. In this study, we examined the phase II metabolism of raloxifene in differentiated Caco-2 monolayers by inducing UGT1A8 and UGT1A10 expression in these cells. The present study evaluated the following four flavonoids of Scutellaria baicalensis as model herbal compounds: scutellarein, salvigenin, baicalein, and wogonin. All test compounds, endpoint substrates, and their metabolites were quantified using liquid chromatography and high-resolution mass spectrometry. The transepithelial electrical resistance values for the individual compounds were comparable regardless of whether they were measured individually. Salvigenin significantly inhibited UGT1A8 and UGT1A10 activities in a concentration-dependent manner. All individual compounds except scutellarein inhibited UGT1A8 and UGT1A10 activity at a concentration of 100 µM. In addition, all individual flavonoids at 100 µM, except wogonin, significantly increased the amount of raloxifene in the basolateral chambers. The positive control, canagliflozin, significantly inhibited both UGT1A8 and UGT1A10 activities. These findings suggest that the Caco-2 assay can be utilized for identifying UGT1A8 and UGT1A10 inhibitors and indicate the potential of salvigenin for enhancing the pharmacological effects of UGT substrate drugs.

Comparative global immune-related gene profiling of somatic cells, human pluripotent stem cells and their derivatives: implication for human lymphocyte proliferation.

Human pluripotent stem cells (hPSCs), including embryonic stem cells (ESCs) and induced PSCs (iPSCs), represent potentially unlimited cell sources for clinical applications. Previous studies have suggested that hPSCs may benefit from immune privilege and limited immunogenicity, as reflected by the reduced expression of major histocompatibility complex class-related molecules. Here we investigated the global immune-related gene expression profiles of human ESCs, hiPSCs and somatic cells and identified candidate immune-related genes that may alter their immunogenicity. The expression levels of global immune-related genes were determined by comparing undifferentiated and differentiated stem cells and three types of human somatic cells: dermal papilla cells, ovarian granulosa cells and foreskin fibroblast cells. We identified the differentially expressed genes CD24, GATA3, PROM1, THBS2, LY96, IFIT3, CXCR4, IL1R1, FGFR3, IDO1 and KDR, which overlapped with selected immune-related gene lists. In further analyses, mammalian target of rapamycin complex (mTOR) signaling was investigated in the differentiated stem cells following treatment with rapamycin and lentiviral transduction with specific short-hairpin RNAs. We found that the inhibition of mTOR signal pathways significantly downregulated the immunogenicity of differentiated stem cells. We also tested the immune responses induced in differentiated stem cells by mixed lymphocyte reactions. We found that CD24- and GATA3-deficient differentiated stem cells including neural lineage cells had limited abilities to activate human lymphocytes. By analyzing the transcriptome signature of immune-related genes, we observed a tendency of the hPSCs to differentiate toward an immune cell phenotype. Taken together, these data identify candidate immune-related genes that might constitute valuable targets for clinical applications.

Dual role of fatty acid-binding protein 5 on endothelial cell fate: a potential link between lipid metabolism and angiogenic responses.

Fatty acid-binding proteins (FABP) are small molecular mass intracellular lipid chaperones that are expressed in a tissue-specific manner with some overlaps. FABP4 and FABP5 share ~55 % amino acid sequence homology and demonstrate synergistic effects in regulation of metabolic and inflammatory responses in adipocytes and macrophages. Recent studies have shown that FABP4 and FABP5 are also co-expressed in a subset of endothelial cells (EC). FABP4, which has a primarily microvascular distribution, enhances angiogenic responses of ECs, including proliferation, migration, and survival. However, the vascular expression of FABP5 has not been well characterized, and the role of FABP5 in regulation of angiogenic responses in ECs has not been studied to date. Herein we report that while FABP4 and FABP5 are co-expressed in microvascular ECs in several tissues, FABP5 expression is also detected in ECs of larger blood vessels. In contrast to FABP4, EC-FABP5 levels are not induced by VEGF-A or bFGF. FABP5 deficiency leads to a profound impairment in EC proliferation and chemotactic migration. These effects are recapitulated in an ex vivo assay of angiogenesis, the aortic ring assay. Interestingly, in contrast to FABP4-deficient ECs, FABP5-deficient ECs are significantly more resistant to apoptotic cell death. The effect of FABP5 on EC proliferation and survival is mediated, only in part, by PPARδ-dependent pathways. Collectively, these findings demonstrate that EC-FABP5, similar to EC-FABP4, promotes angiogenic responses under certain conditions, but it can also exert opposing effects on EC survival as compared to EC-FABP4. Thus, the balance between FABP4 and FABP5 in ECs may be important in regulation of angiogenic versus quiescent phenotypes in blood vessels.

Fatty acid binding protein 4 regulates VEGF-induced airway angiogenesis and inflammation in a transgenic mouse model: implications for asthma.

Neovascularization of the airways occurs in several inflammatory lung diseases, including asthma. Vascular endothelial growth factor (VEGF) plays an important role in vascular remodeling in the asthmatic airways. Fatty acid binding protein 4 (FABP4 or aP2) is an intracellular lipid chaperone that is induced by VEGF in endothelial cells. FABP4 exhibits a proangiogenic function in vitro, but whether it plays a role in modulation of angiogenesis in vivo is not known. We hypothesized that FABP4 promotes VEGF-induced airway angiogenesis and investigated this hypothesis with the use of a transgenic mouse model with inducible overexpression of VEGF165 under a CC10 promoter [VEGF-TG (transgenic) mice]. We found a significant increase in FABP4 mRNA levels and density of FABP4-expressing vascular endothelial cells in mouse airways with VEGF overexpression. FABP4(-/-) mouse airways showed a significant decrease in neovessel formation and endothelial cell proliferation in response to VEGF overexpression. These alterations in airway vasculature were accompanied by attenuated expression of proinflammatory mediators. Furthermore, VEGF-TG/FABP4(-/-) mice showed markedly decreased expression of endothelial nitric oxide synthase, a well-known mediator of VEGF-induced responses, compared with VEGF-TG mice. Finally, the density of FABP4-immunoreactive vessels in endobronchial biopsy specimens was significantly higher in patients with asthma than in control subjects. Taken together, these data unravel FABP4 as a potential target of pathologic airway remodeling in asthma.

Endothelial cell-fatty acid binding protein 4 promotes angiogenesis: role of stem cell factor/c-kit pathway.

Fatty acid binding protein 4 (FABP4) plays an important role in regulation of glucose and lipid homeostasis as well as inflammation through its actions in adipocytes and macrophages. FABP4 is also expressed in a subset of endothelial cells, but its role in this cell type is not known. We found that FABP4-deficient human umbilical vein endothelial cells (HUVECs) demonstrate a markedly increased susceptibility to apoptosis as well as decreased migration and capillary network formation. Aortic rings from FABP4(-/-) mice demonstrated decreased angiogenic sprouting, which was recovered by reconstitution of FABP4. FABP4 was strongly regulated by mTORC1 and inhibited by Rapamycin. FABP4 modulated activation of several important signaling pathways in HUVECs, including downregulation of P38, eNOS, and stem cell factor (SCF)/c-kit signaling. Of these, the SCF/c-kit pathway was found to have a major role in attenuated angiogenic activity of FABP4-deficient ECs as provision of exogenous SCF resulted in a significant recovery in cell proliferation, survival, morphogenesis, and aortic ring sprouting. These data unravel a novel pro-angiogenic role for endothelial cell-FABP4 and suggest that it could be exploited as a potential target for diseases associated with pathological angiogenesis.

Up-regulation of interleukin-17 expression by human papillomavirus type 16 E6 in nonsmall cell lung cancer.

BACKGROUND: Human papillomavirus (HPV) 16/18 infection is associated with nonsmoking lung cancer. In this study, the authors investigated a putative correlation between interleukin (IL)-17 expression and HPV infection in clinical nonsmall cell lung cancer (NSCLC) tissues and examined the effects of HPV infection on a human NSCLC cell line. METHODS: IL-17 expression was investigated in 79 NSCLC tumor tissues by immunohistochemistry. Growth rate, IL-17 mRNA, and secreting protein levels were also examined in HPV 16/18 E6-transfected H1299 human NSCLC cells. RESULTS: Immunohistochemical data showed that 48.1% of lung tumors had IL-17 staining, which was significantly associated with patients' sex (P = .03), HPV infection (P = .002), and tumor stage (P = .03). Significant correlations of IL-17 with IL-6 (P < .001) and IL-17 with Mcl-1 (P < .001) expression were also observed. Cell growth rate was increased, and IL-17/Mcl-1 expression levels were elevated in HPV 16 E6-transfected H1299 cells. The transfected E6 oncoproteins can significantly up-regulate expression levels of IL-17 and antiapoptotic protein Mcl-1. CONCLUSIONS: The study suggests that HPV infection-induced IL-17 levels can stimulate Mcl-1 expression through the PI3K pathway and promote lung tumor cell progression through a p53- and IL-6-independent pathway.

Spontaneous differentiation of adult rat marrow stromal cells in a long-term culture.

It is well recognized that bone marrow stromal cells (MSCs) can differentiate into neuron-like cells when supplemented with growth factors and/or chemical treatments. We demonstrated that primary MSCs obtained from adult rats could spontaneously differentiate into neural precursor cells after long-term culture. During the outset of in vitro culture, less than 0.1% of adult rat primary MSCs expressed nestin, the common protein of neural precursors. These MSCs didn't show neuronal morphology nor express neuronal antigens. In contrast, after continuous maintenance for 6 weeks, a significant subpopulation of MSCs formed cellular clumps and expressed nestin (32.3 +/- 6.3%). Less than 0.1% of cells expressing immature neuron marker betaIII-tubulin could be detected in these prolonged cultured MSCs. After serum deprivation and growth factor supplement, these nestin-positive cells could express neuron-like morphology and neuron-specific markers NF-H, betaIII-tubulin, tau, and neurotransmitter GABA. In contrast, the MSCs without prolonged culture didn't show neuronal morphology nor neuronal markers even after serum withdrawal and growth factors stimulation. These results demonstrated that neural precursors could be obtained from long-term cultured MSCs, and suggested that MSCs should be useful as a potential source for treatment of neurological disease.