Epstein-Barr virus suppresses N6-methyladenosine modification of TLR9 to promote immune evasion.

Epstein-Barr virus (EBV) is a human tumor virus associated with a variety of malignancies, including nasopharyngeal carcinoma, gastric cancers, and B-cell lymphomas. N6-methyladenosine (m6A) modifications modulate a wide range of cellular processes and participate in the regulation of virus-host cell interactions. Here, we discovered that EBV infection downregulates toll-like receptor 9 (TLR9) m6A modification levels and thus inhibits TLR9 expression. TLR9 has multiple m6A modification sites. Knockdown of METTL3, an m6A "writer", decreases TLR9 protein expression by inhibiting its mRNA stability. Mechanistically, Epstein-Barr nuclear antigen 1 increases METTL3 protein degradation via K48-linked ubiquitin-proteasome pathway. Additionally, YTHDF1 was identified as an m6A "reader" of TLR9, enhancing TLR9 expression by promoting mRNA translation in an m6A -dependent manner, which suggests that EBV inhibits TLR9 translation by "hijacking" host m6A modification mechanism. Using the METTL3 inhibitor STM2457 inhibits TLR9-induced B cell proliferation and immunoglobulin secretion, and opposes TLR9-induced immune responses to assist tumor cell immune escape. In clinical lymphoma samples, the expression of METTL3, YTHDF1, and TLR9 was highly correlated with immune cells infiltration. This study reveals a novel mechanism that EBV represses the important innate immunity molecule TLR9 through modulating the host m6A modification system.

Epstein-Barr virus microRNA miR-BART2-5p accelerates nasopharyngeal carcinoma metastasis by suppressing RNase â ¢ endonuclease DICER1.

The development and progression of nasopharyngeal carcinoma (NPC) is closely associated with Epstein-Barr virus (EBV) infection. NPC is usually asymptomatic until it spreads to other sites, and more than 70% of cases are classified as locally advanced disease at diagnosis. EBV-positive nasopharyngeal cancer tissues express only limited viral latent proteins, but express high levels of the EBV-encoded BamHI-A rightward transcript (BART) miRNA molecules. Here, we report that EBV-miRNA-BART2-5p (BART2-5p) promotes NPC cell invasion and metastasis in vivo and in vitro but has no effect on NPC cell proliferation and apoptosis. In addition, BART2-5p altered the mRNA and miRNA expression profiles of NPC cells. The development of human tumors has been reported to be associated with altered miRNAs expression, and overall miRNAs expression is reduced in many types of tumors. We found that BART2-5p downregulated the expression of several miRNAs that could exert oncogenic functions. Mechanistically, BART2-5p directly targets the RNase III endonuclease DICER1, inhibiting its function of cleaving double-stranded stem-loop RNA into short double-stranded RNA, which in turn causes altered expression of a series of key epithelial-mesenchymal transition molecules, and reverting DICER1 expression can rescue this phenotype. Furthermore, analysis from clinical samples showed a negative correlation between BART2-5p and DICER1 expression. According to our study, high expression of BART2-5p in tissues and plasma of patients with NPC is associated with poor prognosis. Our results suggest that, BART2-5p can accelerate NPC metastasis through modulating miRNA profiles which are mediated by DICER1, implying a novel role of EBV miRNAs in the pathogenesis of NPC.

HDAC6 inhibitor ACY-1215 enhances STAT1 acetylation to block PD-L1 for colorectal cancer immunotherapy.

The search for effective combination therapy with immune checkpoint inhibitors (ICI) has become important for cancer patients who do not respond to the ICI well. Histone deacetylases (HDACs) inhibitors have attracted wide attention as anti-tumor agents. ACY-1215 is a selective inhibitor of HDAC6, which can inhibit the growth of a variety of tumor. We previously revealed that HDAC family is highly expressed in colorectal cancer specimens and mouse models. In this study, ACY-1215 was combined with anti-PD1 to treat tumor-bearing mice associated with colorectal cancer. ACY-1215 combined with anti-PD1 effectively inhibited the colorectal tumor growth. The expression of PD-L1 in tumor of mice were inhibited by ACY-1215 and anti-PD1 combination treatment, whereas some biomarkers reflecting T cell activation were upregulated. In a co-culture system of T cells and tumor cells, ACY-1215 helped T cells to kill tumor cells. Mechanically, HDAC6 enhanced the acetylation of STAT1 and inhibited the phosphorylation of STAT1, thus preventing STAT1 from entering the nucleus to activate PD-L1 transcription. This study reveals a novel regulatory mechanism of HDAC6 on non-histone substrates, especially on protein acetylation. HDAC6 inhibitors may be of great significance in tumor immunotherapy and related combination strategies.

Evaluating the effect of childhood sunburn on the risk of cutaneous melanoma through Mendelian randomization.

Despite numerous observational studies indicating an increased risk of cutaneous melanoma (CM) due to childhood sunburn, no studies have established a definitive cause-and-effect relationship. Therefore, our objective was to employ a Mendelian randomization (MR) design to explore a possible causal association between childhood sunburn and the risk of CM. To investigate the causal relationship between childhood sunburn and CM, we used large-scale genetic summary-level data from genome-wide association studies (GWAS), including childhood sunburn (n = 346,955) and CM (n = 262,288), building upon previous observational studies. In the analysis, we mainly used the inverse-variance weighted (IVW) method of the random effects model, supplemented by the weighted median method and MR-Egger method. The results of the IVW method demonstrated that genetically predicted childhood sunburn was significantly associated with higher odds of CM, with an odds ratio (OR) of 2.418 (95%CI, 1.426-4.099; p = .001). The weighted median method and MR-Egger regression also demonstrated directionally similar results (both p < .05). Furthermore, both the funnel plot and the MR-Egger intercepts showed the absence of directional pleiotropy between childhood sunburn and CM. Our study offers potential evidence linking genetically predicted childhood sunburn with CM, underscoring the need for individuals with a history of childhood sunburn to be extra vigilant regarding the occurrence of CM.

Long non-coding RNA MSTRG.81401 short hairpin RNA relieves diabetic neuropathic pain and behaviors of depression by inhibiting P2X4 receptor expression in type 2 diabetic rats.

Patients with diabetic neuropathic pain (DNP) experience immense physical and mental suffering, which is comorbid with other mental disorders, including major depressive disorder (MDD). P2X4 receptor, one of the purinergic receptors, is a significant mediator of DNP and MDD. The present study aimed to identify the roles and mechanisms of MSTRG.81401, a long non-coding RNA (lncRNA), in alleviating DNP and MDD-like behaviors in type 2 diabetic rats. After administration with MSTRG.81401 short hairpin RNA (shRNA), the model + MSTRG.81401 shRNA group demonstrated increased mechanical withdrawal threshold, thermal withdrawal latency, open-field test, and sucrose preference test; however, immobility time on the forced swimming test decreased. MSTRG.81401 shRNA administration significantly decreased the expression of the P2X4 receptor, tumor necrosis factor-α, and interleukin-1ß in the hippocampus and spinal cord in the model + MSTRG.81401 shRNA group. Simultaneously, MSTRG.81401 shRNA administration downregulated phosphorylation of ERK1/2 in the hippocampus and spinal cord. Thus, lncRNA MSTRG.81401 shRNA can alleviate DNP and MDD-like behaviors in type 2 diabetic rats and may downregulate the expression of P2X4 receptors in the hippocampus and spinal cord of rats.

Deficiency of Lactoferrin aggravates lipopolysaccharide-induced acute inflammation via recruitment macrophage in mice.

Lactoferrin (Lf), a multiple functional natural immune protein, is widely distributed in mammalian milk and glandular secretions (bile, saliva, tears and nasal mucosal secretions, etc.). In the previous study, we found that Lf plays an anti-inflammatory and anti-tumorigenesis role in AOM/DSS (azoxymethane/dextran sulfate sodium) induced mouse colitis-associated colon cancer model. Although we found that Lf has anti-inflammatory effects in chronic inflammation, its specific role and mechanisms in acute inflammation have not been clarified. Here, we reported that the expression levels of Lf were significantly increased when the organism was infected by Gram-negative bacteria. We then explored the role and potential mechanism of Lf in lipopolysaccharide (LPS)-induced acute inflammation. In the LPS-induced acute abdominal inflammation model, Lf deficiency aggravated inflammatory response and promoted macrophage chemotaxis to the inflammation site. Lf inhibited macrophage chemotaxis by suppressing the expression of macrophage-associated chemokines Ccl2 and Ccl5. Highly activated NF-κB signaling in Lf-/- mice was responsible for the high expression of Ccl2 and Ccl5. Our results suggested that the anti-inflammatory effect of Lf offers a new potential treatment for acute inflammatory diseases.

Imperatorin Improves Obesity-Induced Cardiac Sympathetic Nerve Injury Mediated by P2X4 Receptor in Stellate Sympathetic Ganglion.

Obesity can activate the inflammatory signal pathway, induce in the body a state of chronic inflammation, and increase the excitability of the sympathetic nervous system, which may induce sympathetic neuropathic injury. The stellate sympathetic ganglia (SG) can express the P2X4 receptor, and the abnormal expression of the P2X4 receptor is related to inflammation. Imperatorin (IMP) is a kind of furan coumarin plant which has anti-inflammatory effects. This project aimed to investigate whether IMP can affect the expression of P2X4 receptors in the SG of obese rats to display a protective effect from high-fat-triggered cardiac sympathetic neuropathic injury. Molecular docking through homology modelling revealed that IMP had good affinity for the P2X4 receptor. Our results showed that compared with the normal group, the administration of IMP or P2X4 shRNA decreased sympathetic excitement; reduced the serum levels of triglyceride, total cholesterol, and lactate dehydrogenase; downregulated the expression of P2X4 receptors in SG; and inhibited the expression of inflammatory factors in the SG and serum of obese rats significantly. In addition, the expression of factors associated with the cell pyroptosis GSDMD, caspase-1, NLRP-3, and IL-18 in obese rats were significantly higher than those of the normal rats, and such effects were decreased after treatment with IMP or P2X4 shRNA. Furthermore, IMP significantly reduced the ATP-activated currents in HEK293 cells transfected with P2X4 receptor. Thus, the P2X4 receptor may be a key target for the treatment of obesity-induced cardiac sympathetic excitement. IMP can improve obesity-induced cardiac sympathetic excitement, and its mechanism of action may be related to the inhibition of P2X4 receptor expression and activity in the SG, suppression of cellular pyroptosis in the SG, and reduction of inflammatory factor levels.

Gallic Acid Alleviates Visceral Pain and Depression via Inhibition of P2X7 Receptor.

Chronic visceral pain can occur in many disorders, the most common of which is irritable bowel syndrome (IBS). Moreover, depression is a frequent comorbidity of chronic visceral pain. The P2X7 receptor is crucial in inflammatory processes and is closely connected to developing pain and depression. Gallic acid, a phenolic acid that can be extracted from traditional Chinese medicine, has been demonstrated to be anti-inflammatory and anti-depressive. In this study, we investigated whether gallic acid could alleviate comorbid visceral pain and depression by reducing the expression of the P2X7 receptor. To this end, the pain thresholds of rats with comorbid visceral pain and depression were gauged using the abdominal withdraw reflex score, whereas the depression level of each rat was quantified using the sucrose preference test, the forced swimming test, and the open field test. The expressions of the P2X7 receptor in the hippocampus, spinal cord, and dorsal root ganglion (DRG) were assessed by Western blotting and quantitative real-time PCR. Furthermore, the distributions of the P2X7 receptor and glial fibrillary acidic protein (GFAP) in the hippocampus and DRG were investigated in immunofluorescent experiments. The expressions of p-ERK1/2 and ERK1/2 were determined using Western blotting. The enzyme-linked immunosorbent assay was utilized to measure the concentrations of IL-1ß, TNF-α, and IL-10 in the serum. Our results demonstrate that gallic acid was able to alleviate both pain and depression in the rats under study. Gallic acid also reduced the expressions of the P2X7 receptor and p-ERK1/2 in the hippocampi, spinal cords, and DRGs of these rats. Moreover, gallic acid treatment decreased the serum concentrations of IL-1ß and TNF-α, while raising IL-10 levels in these rats. Thus, gallic acid may be an effective novel candidate for the treatment of comorbid visceral pain and depression by inhibiting the expressions of the P2X7 receptor in the hippocampus, spinal cord, and DRG.

Identification of a universal 6-lncRNA prognostic signature for three pathologic subtypes of renal cell carcinoma.

Renal cell carcinoma (RCC) is the most common adult renal epithelial cancer susceptible to metastasis and patients with irresectable RCC always have a poor prognosis. Long noncoding RNAs (lncRNAs) have recently been documented as having critical roles in the etiology of RCC. Nevertheless, the prognostic significance of lncRNA-based signature for outcome prediction in patients with RCC has not been well investigated. Therefore, it is essential to identify a lncRNA-based signature for predicting RCC prognosis. In the current study, we comprehensively analyzed the RNA sequencing data of the three main pathological subtypes of RCC (kidney renal clear cell carcinoma [KIRC], kidney renal papillary cell carcinoma [KIRP], and kidney chromophobe carcinoma [KICH]) from The Cancer Genome Atlas (TCGA) database, and identified a 6-lncRNA prognostic signature with the help of a step-wise multivariate Cox regression model. The 6-lncRNA signature stratified the patients into low- and high-risk groups with significantly different prognosis. Multivariate Cox regression analysis showed that predictive value of the 6-lncRNA signature was independent of other clinical or pathological factors in the entire cohort and in each cohort of RCC subtypes. In addition, the three independent prognostic clinical factors (including age, pathologic stage III, and stage IV) was also stratified into low- and high-risk groups basis on the risk score, and the stratification analyses demonstrated that the high-risk score was a poor prognostic factor. In conclusion, these findings indicate that the 6-lncRNA signature is a novel prognostic biomarker for all three subtypes of RCC, and can increase the accuracy of predicting overall survival.

Suppression of angiogenesis and tumor growth by recombinant T4 phages displaying extracellular domain of vascular endothelial growth factor receptor 2.

Tumor growth, invasion and metastasis are dependent on angiogenesis. The Vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR2) signaling pathway plays a pivotal role in tumor angiogenesis and therefore represents a reasonable target for anti-angiogenesis/anti-tumor therapy. In the present study, we generated T4 recombinant phages expressing the extracellular domain of VEGFR2 (T4-VEGFR2) and investigated their anti-angiogenic activity. The T4-VEGFR2 phages were able to bind to VEGF specifically and inhibit VEGF-mediated phosphorylation of VEGFR2 and its downstream kinases such as extracellular signal-regulated kinase (ERK) and p38 mitogen activated protein kinase (MAPK). The in vitro experiments showed that the T4-VEGFR2 phages could inhibit VEGF-stimulated cell proliferation and migration of endothelial cells. Finally, administration of T4-VEGFR2 phages was able to suppress tumor growth and decrease microvascular density in murine models of Lewis lung carcinoma and colon carcinoma, and prolong the survival of tumor bearing mice. In conclusion, this study reveals that the recombinant T4-VEGFR2 phages generated using T4-based phage display system can inhibit VEGF-mediated tumor angiogenesis and the T4 phage display technology can therefore be used for the development of novel anti-cancer strategies.

[Role of IgG plasma cells in the change of protein C system in ulcerative colitis].

The present study is designed to explore the role of plasma cells in the change of protein C system (PCS) in ulcerative colitis (UC). Dextran sulfate sodium (DSS, 4% in concentration) was used to induce mouse UC model. The plasma cells and the type of immune complex in colon were observed by immunofluorescence. The amount and type of plasma cells separated from colonic mucosal lamina propria were detected by flow cytometry using anti-CD54+CD38+ and IgA/M/G antibodies, respectively. After stimulation of macrophages by IgG type immune complex, TNF-α and IL-6 levels were evaluated by ELISA. After co-incubation of microvascular endothelial cells with TNF-α or IL-6, the expressions of endothelial protein C receptor (EPCR) and thrombomodulin (TM), and the activity of activated protein C (APC) were examined. As the results showed, the IgG type plasma cells infiltration and the quantity of IgG type immune complex were increased in DSS group in comparison with control group. After incubation with IgG type immune complex, the levels of TNF-α and IL-6 in the supernatant of macrophages were increased (P < 0.01) in a concentration-dependent manner. Meanwhile, after incubation with TNF-α or IL-6, the expressions of EPCR and TM in the microvascular endothelial cells were decreased (P < 0.05 or P < 0.01), while the activity of APC was reduced (P < 0.05 or P < 0.01). These results suggested that the quantity of IgG type plasma cells increases in UC and forms immune complexes, which affect the secretion of cytokines from macrophage, thereby affecting the function of endothelial cells and finally inhibiting PCS in UC. Therefore, plasma cell may be a novel target for the treatment of UC.

Advanced lung cancer inflammation index is associated with prognosis in skin cancer patients: a retrospective cohort study.

Background: Skin cancer ranks as one of the most prevalent malignant tumors affecting humans. This study was designed to explore the correlation between the advanced lung cancer inflammation index (ALI), a metric that gauged both nutrition and inflammation statuses, in skin cancer patients and their subsequent prognosis. Methods: Data from the National Health and Nutrition Examination Survey (NHANES) spanning 1999-2018 were scrutinized, along with mortality tracking extending to December 31, 2019. Kaplan-Meier survival curves and COX regression analysis, utilizing NHANES-recommended weights, delineated the association between ALI levels and skin cancer prognosis. To decipher the potential non-linear relationship, a restricted cubic spline analysis was applied. Additionally, stratified analysis was conducted to affirm the robustness of our findings. Results: The 1,149 patients participating in NHANES 1999-2018 were enrolled. We observed a reverse J-shaped non-linear relationship between ALI and both skin cancer all-cause mortality and cancer mortality, with inflection points at 81.13 and 77.50, respectively. Conclusions: The ALI served as a comprehensive indicator of a patient's nutrition and inflammation status and was demonstrably linked to the prognosis in skin cancer cases. The meticulous evaluation and continuous monitoring of these parameters in skin cancer patients bear clinical importance.

Association between genetically predicted rheumatoid arthritis and alopecia areata: a two-sample Mendelian randomization study.

Background: Although numerous observational studies have indicated a potential association between autoimmune diseases, such as rheumatoid arthritis (RA) and alopecia areata (AA), the research reports lack a clear causal relationship. In this study, our objective is to utilize the Mendelian randomization (MR) design to examine the potential causal association between RA and AA. Methods: To investigate the causal relationship between RA and AA, we utilized large-scale gene aggregation data from genome-wide association studies (GWAS), including RA (n=58,284) and AA (n=361,822) based on previous observational studies. In our analysis, we mainly employed the inverse variance-weighted (IVW) method of the random effects model, supplemented by the weighted median (WM) method and the MR Egger method. Results: The findings from the IVW methods revealed a significant association between genetically predicted RA and an increased likelihood of AA, as evidenced by an odds ratio of 1.21 (95%CI = 1.11-1.32; P < 0.001. Both the WM method and MR-Egger regression consistently showed significant directional outcomes (Both P < 0.05), indicating a robust association between RA and AA. Additionally, both the funnel plot and the MR-Egger intercepts provided evidence of the absence of directional pleiotropy, suggesting that the observed association is not influenced by other common genetic factors. Conclusions: The results of the study suggest a possible link between genetically predicted RA and AA. This finding highlights the importance for individuals diagnosed with RA to remain vigilant and aware of the potential development of AA. Regular monitoring and early detection can be crucial in managing and addressing this potential complication.

JHDM1D-AS1-driven inhibition of miR-940 releases ARTN expression to induce breast carcinogenesis.

INTRODUCTION: As ceRNA network of long non-coding RNA (lncRNA)-microRNA (miR)-messenger RNAs (mRNA) can be predicted on the basis of bioinformatics tools, we are now one step closer to deeper understanding carcinogenic mechanisms. In this study, we clarified the mechanistic understanding of JHDM1D-AS1-miR-940-ARTN ceRNA network in the development of breast cancer (BC). MATERIALS AND METHODS: The lncRNA-miRNA-mRNA interaction of interest was predicted by in silico analysis and identified by conducting RNA immunoprecipitation, RNA pull-down and luciferase assays. The expression patterns of JHDM1D-AS1, miR-940 and ARTN in BC cells were altered by lentivirus infection and plasmid transfection for functional assays on the biological properties of BC cells. Finally, the tumorigenic and metastatic abilities of BC cells were assessed in vivo. RESULTS: JHDM1D-AS1 was highly expressed, while miR-940 was poorly expressed in BC tissues and cells. JHDM1D-AS1 could competitively bind to miR-940, whereby promoting the malignant behaviors of BC cells. Furthermore, ARTN was identified as a target gene of miR-940. Through targeting ARTN, miR-940 exerted a tumor-suppressive role. In vivo experiments further confirmed that JHDM1D-AS1 enhanced the tumorigenesis and metastasis through up-regulation of ARTN. CONCLUSIONS: Taken together, our study demonstrated the involvement of ceRNA network JHDM1D-AS1-miR-940-ARTN in the progression of BC, which highlighted promising therapeutic targets for BC treatment.

Phase separation drives the formation of biomolecular condensates in the immune system.

When the external conditions change, such as the temperature or the pressure, the multi-component system sometimes separates into several phases with different components and structures, which is called phase separation. Increasing studies have shown that cells condense related biomolecules into independent compartments in order to carry out orderly and efficient biological reactions with the help of phase separation. Biomolecular condensates formed by phase separation play a significant role in a variety of cellular processes, including the control of signal transduction, the regulation of gene expression, and the stress response. In recent years, many phase separation events have been discovered in the immune response process. In this review, we provided a comprehensive and detailed overview of the role and mechanism of phase separation in the innate and adaptive immune responses, which will help the readers to appreciate the advance and importance of this field.

Histone deacetylase (HDAC) 11 inhibits matrix metalloproteinase (MMP) 3 expression to suppress colorectal cancer metastasis.

Emerging evidence has implicated invasion and metastasis are the major common reason of treatment failure and the leading cause of death in colorectal cancer (CRC). Many members of the HDAC family have been reported to be key factors in the genesis and progression of cancer. Until now, few research focused on the actual expression patterns of HDAC11 in most malignancies. In the current study, we found that the expression of HDAC11 is decreased in mouse colitis tissues and colitis-associated cancer (CAC) tissue compared with normal colon tissue. Clinically HDAC11 expression is significantly lower in colorectal cancer tissues of patients and correlated with lymph node metastasis. Additionally, HDAC11 is downregulated in the relative high metastatic potential colorectal cancer cells. We also found HDAC11 inhibits the migration and invasion of colorectal cancer cell by downregulating Mmp3 expression. At the molecular level, the expression of HDAC11 inversely correlated with the level of histone H3K9 and H3K14 acetylation. In addition, analysis of chromatin-protein association by ChIP-qPCR demonstrated that the level of H3K9 acetylation correlated with the upregulation of Mmp3. Through a better understanding of this previously unknown role of HDAC11 in migration and invasion of colorectal cancer, HDAC11 may become a novel candidate for developing rational therapeutic strategies.

Macrophage-Biomimetic Nanoparticles Ameliorate Ulcerative Colitis through Reducing Inflammatory Factors Expression.

BACKGROUND AND AIMS: Inflammatory mediator S100A9 is dramatically elevated in ulcerative colitis and correlates with disease severity. S100A9 is a potential molecule to target for the treatment of colitis, but to date, there is no effective targeting method. The aim of this study was to develop a safe and effective nano-delivery system targeting S100A9 and to evaluate its therapeutic efficacy in ulcerative colitis mouse model. METHODS: We designed an oral nano-delivery system using poly (lactic acid-glycolic acid) (PLGA)-loaded S100A9 inhibitor tasquinimod to synthesize PLGA-TAS nanoparticles. TLR4-overexpressing macrophage membranes (MMs) were used to wrap the nanoparticles to make MM-PLGA-TAS, which allowed the nanoparticles to acquire the ability to specifically enrich the colitis region. RESULTS: MM-PLGA-TAS was endocytosed by inflammatory phenotype RAW264.7 cells in vitro and can efficiently enrich in inflamed mouse colitis tissue in vivo. A chemically induced ulcerative colitis mouse model was used to evaluate the therapeutic effect of oral MM-PLGA-TAS. MM-PLGA-TAS significantly alleviated the symptoms of ulcerative colitis, and mechanically, MM-PLGA-TAS achieved immunomodulatory and suppressive effects by reducing S100a9 and other cytokines in the colitis region. CONCLUSION: We describe a convenient, orally targeted colitis drug delivery system that cures the disease in ulcerative colitis mice. This system substantially increases drug accumulation in inflamed colonic tissue, reduces the risk of systemic exposure, and is a promising therapeutic approach against ulcerative colitis.

The HIF-1/SNHG1/miR-199a-3p/TFAM axis explains tumor angiogenesis and metastasis under hypoxic conditions in breast cancer.

Activation of hypoxia-inducible factors (HIFs) as a result of intratumoral hypoxia modulates a cascade of molecular pathways thus leading to angiogenesis and metastasis in many solid tumors, including breast cancer (BC). In our paper, we report a regulatory axis of HIF-1, SNHG1, miR-199a-3p, and mitochondrial transcription factor A (TFAM) involved in tumor angiogenesis and metastasis under hypoxic conditions in BC. The expression of SNHG1 was determined in human BC cells cultured in hypoxia (1% O2 , 24 h) and normoxia (20% O2 , 24 h). Cultured MDA-MB-231 cells were assayed for the proliferation, migration, invasion, angiogenesis in vitro by using EdU staining, transwell chamber assays, Matrigel-based angiogenesis assays, tumorigenesis, and lung metastasis in vivo by using an orthotopic-transplant model of human BC. Dual-luciferase reporter assay, chromatin immunoprecipitation quantitative polymerase chain reaction assay, fluorescence in situ hybridization assay, RNA-binding protein immunoprecipitation assay, and RNA pull-down were performed to test interaction between HIF-1 and SNHG1, SNHG1 and miR-199a-3p, miR-199a-3p and TFAM. SNHG1 was increased under hypoxic conditions at a HIF-1-dependent manner. SNHG1 knockdown tempered MDA-MB-231 cell proliferation, migration, invasion, angiogenesis, in vitro, tumorigenesis, and lung metastasis in vitro. SNHG1 was co-expressed with miR-199a-3p and regulated the TFAM, a target gene of miR-199a-3p. SNHG1 increased the TFAM by binding with miR-199a-3p, thus promoting BC development and metastasis. These results support a regulatory axis consisting of HIF-1, SNHG1, miR-199a-3p, and TFAM during BC development and metastasis under hypoxic conditions, providing an opportunity to develop targeted therapeutics for BC.

Lactoferrin is required for early B cell development in C57BL/6 mice.

Lactoferrin (Lf) is widely distributed in mammalian milk, various tissues, and their exocrine fluids and has many physiological functions, such as bacteriostasis, antivirus, and immunoregulation. Here, we provide evidence that lactoferrin is required for early stages of B cell development in mice. Lactoferrin-deficient (Lf-/-) C57BL/6 mice showed systematic reduction in total B cells, which was attributed to the arrest of early B cell development from pre-pro-B to pro-B stage. Although the Lf-/- B cell "seeds" generated greater pro-B cells comparing to wild type (WT) littermates, the Lf-/- mice bone marrow had less stromal cells, and lower CXCL12 expression, produced a less favorable "microenvironment" for early B cell development. The underlying mechanism was mediated through ERK and AKT signalings and an abnormality in the transcription factors related to early differentiation of B cells. The Lf-/- mice also displayed abnormal antibody production in T cell-dependent and T cell-independent immunization experiments. In a pristane-induced lupus model, Lf-/- mice had more serious symptoms than WT mice, whereas lactoferrin treatment alleviated these symptoms. This study demonstrates a novel role of lactoferrin in early B cell development, suggesting a potential benefit for using lactoferrin in B cell-related diseases.

N6-methyladenosine regulates ATM expression and downstream signaling.

N6-methyladenosine (m6A) is the most abundant modification in eukaryotic mRNAs, which plays an important role in regulating multiple biological processes. ATM is a major protein kinase that regulates the DNA damage response. Here, we identified that ATM is a m6A-modificated gene. METTL3 (a m6A "writer") and FTO (a m6A "eraser") oppositely regulated ATM expression and its downstream signaling. Mechanically, m6A "readers" YTHDFs and eIF3A suppressed ATM expression in the post-transcriptional levels. We also revealed the oncogenic potential of METTL3 and YTHDF1 related to ATM modulation. This is the first report that ATM, a master in the DNA damage response, is modified by m6A epigenetic modification, and METTL3 disrupts the ATM stability via m6A modification, thereby affecting the DNA-damage response.