CARM1 drives triple-negative breast cancer progression by coordinating with HIF1A.

Coactivator-associated arginine methyltransferase 1 (CARM1) promotes the development and metastasis of estrogen receptor alpha (ERα)-positive breast cancer. The function of CARM1 in triple-negative breast cancer (TNBC) is still unclear and requires further exploration. Here, we report that CARM1 promotes proliferation, epithelial-mesenchymal transition (EMT), and stemness in TNBC. CARM1 is upregulated in multiple cancers and its expression correlates with breast cancer progression. Genome-wide analysis of CARM1 showed that CARM1 is recruited by hypoxia-inducible factor 1 subunit alpha (HIF1A) and occupy the promoters of CDK4, Cyclin D1, ß-catenin, HIF1A, MALAT1, and SIX1 critically involved in cell cycle, HIF-1 signaling pathway, Wnt signaling pathway, VEGF signaling pathway, thereby modulating the proliferation and invasion of TNBC cells. We demonstrated that CARM1 is physically associated with and directly interacts with HIF1A. Moreover, we found that ellagic acid, an inhibitor of CARM1, can suppress the proliferation and metastasis of TNBC by directly inhibiting CDK4 expression. Our research has determined the molecular basis of CARM1 carcinogenesis in TNBC and its effective natural inhibitor, which may provide new ideas and drugs for cancer therapy.

Case Report: Targeted Therapy with Anlotinib for a Rare Case of Spinal Cord Glioblastoma with FGFR3 Mutation.

Primary spinal cord glioblastoma (PSC GBM) is a rare disease with limited treatment options. Here, we describe a case of PSC GBM treated with anlotinib in this report. Molecular characterization confirmed the presence of the MGMT promoter unmethylated, IDH wild type, FGFR3 p.S249C and p53 p.V73fs mutations in the patient. Anlotinib is a multitarget tyrosine kinase inhibitor that target VEGFR2/3, FGFR1-4, PDGFRα/ß, and c-kit. After a partial resection of the tumor at the extramedullary invasion site, the patient was administered anlotinib 12 mg p.o. once every day (days 1-14, 21-day cycle) in combination with irinotecan chemotherapy (days 1 and 8, 21-day cycle). The patient exhibited significant symptom remission and partial response and was maintained for more than 10 months of follow-up. This case study showed that FGFR3 S249C may be a new marker for the treatment of PSC GBM with anlotinib. This case is also another strong support for molecular diagnosis and precision medicine.

Snail/PRMT5/NuRD complex contributes to DNA hypermethylation in cervical cancer by TET1 inhibition.

The biological function of PRMT5 remains poorly understood in cervical cancer metastasis. Here, we report that PRMT5 physically associates with the transcription factor Snail and the NuRD(MTA1) complex to form a transcriptional-repressive complex that catalyzes the symmetrical histone dimethylation and deacetylation. This study shows that the Snail/PRMT5/NuRD(MTA1) complex targets genes, such as TET1 and E-cadherin, which are critical for epithelial-mesenchymal transition (EMT). This complex also affects the conversion of 5mC to 5hmC. This study demonstrates that the Snail/PRMT5/NuRD(MTA1) complex promotes the invasion and metastasis of cervical cancer in vitro and in vivo. This study also shows that PRMT5 expression is upregulated in cervical cancer and various human cancers, and the PRMT5 inhibitor EPZ015666 suppresses EMT and the invasion potential of cervical cancer cells by disinhibiting the expression of TET1 and increasing 5hmC, suggesting that PRMT5 is a potential target for cancer therapy.

Regulation of EZH2 by SMYD2-Mediated Lysine Methylation Is Implicated in Tumorigenesis.

The histone methyl transferase enhancer of zeste homolog 2 (EZH2) is a master transcriptional regulator involved in histone H3 lysine 27 trimethylation. We aimed to elucidate the precise post-translational regulations of EZH2 and their role in cancer pathogenesis. Here, we show that SET and MYND domain containing 2 (SMYD2) directly methylates EZH2 at lysine 307 (K307) and enhances its stability, which can be relieved by the histone H3K4 demethylase lysine-specific demethylase 1 (LSD1). SMYD2 is critical for EZH2 function in repressing a cohort of genes governing several cancer-associated pathways. In addition, SMYD2 promotes breast cancer cell proliferation, epithelial-mesenchymal transition, and invasion through EZH2 K307 methylation, and it is markedly upregulated in various human cancers. Our data suggest that dynamic crosstalk between SMYD2-mediated EZH2 methylation plays an important role in fine-tuning EZH2 functions in chromatin recruitment and transcriptional repression.

BRMS1 coordinates with LSD1 and suppresses breast cancer cell metastasis.

Breast carcinoma metastasis suppressor gene 1 (BRMS1) encodes an inhibitor of metastasis and is reported in many types of tumor metastasis. However, the mechanism of BRMS1-mediated inhibition of breast cancer metastasis at the transcriptional level remains elusive. Here, we identified using affinity purification and mass spectrometry (MS) that BRMS1 is an integral component of the LSD1/CoREST corepressor complex. Analysis of the BRMS1/LSD1 complex using high-throughput RNA deep sequencing (RNA-seq) identified a cohort of target genes such as VIM, INSIG2, KLK11, MRPL33, COL5A2, OLFML3 and SLC1A1, some of which are metastasis-related. Our results have showed that BRMS1 together with LSD1 are required for inhibition of breast cancer cell migration and invasion. Collectively, these findings demonstrate that BRMS1 executes transcriptional suppression of breast cancer metastasis by associating with the LSD1 and thus can be targeted for breast cancer therapy.

Proteomic analysis of the OGT interactome: novel links to epithelial-mesenchymal transition and metastasis of cervical cancer.

The role of O-GlcNAc transferase (OGT) in gene regulation and tumor invasion is poorly understood. Here, we have identified several previously undiscovered OGT-interacting proteins, including the PRMT5/WDR77 complex, the PRC2 complex, the ten-eleven translocation (TET) family, the CRL4B complex and the nucleosome remodeling and deacetylase (NuRD) complex. Genome-wide analysis of target genes responsive to OGT resulted in identification of a cohort of genes including SNAI1 and ING4 that are critically involved in cell epithelial-mesenchymal transition and invasion/metastasis. We have demonstrated that OGT promotes carcinogenesis and metastasis of cervical cancer cells. OGT's expression is significantly upregulated in cervical cancer, and low OGT level is correlated with improved prognosis. Our study has thus revealed a mechanistic link between OGT and tumor progression, providing potential prognostic indicators and targets for cancer therapy.

LSD1 coordinates with the SIN3A/HDAC complex and maintains sensitivity to chemotherapy in breast cancer.

Lysine-specific demethylase 1 (LSD1) was the first histone demethylase identified as catalysing the removal of mono- and di-methylation marks on histone H3-K4. Despite the potential broad action of LSD1 in transcription regulation, recent studies indicate that LSD1 may coordinate with multiple epigenetic regulatory complexes including CoREST/HDAC complex, NuRD complex, SIRT1, and PRC2, implying complicated mechanistic actions of this seemingly simple enzyme. Here, we report that LSD1 is also an integral component of the SIN3A/HDAC complex. Transcriptional target analysis using ChIP-on-chip technology revealed that the LSD1/SIN3A/HDAC complex targets several cellular signalling pathways that are critically involved in cell proliferation, survival, metastasis, and apoptosis, especially the p53 signalling pathway. We have demonstrated that LSD1 coordinates with the SIN3A/HDAC complex in inhibiting a series of genes such as CASP7, TGFB2, CDKN1A(p21), HIF1A, TERT, and MDM2, some of which are oncogenic. Our experiments also found that LSD1 and SIN3A are required for optimal survival and growth of breast cancer cells while also essential for the maintenance of epithelial homoeostasis and chemosensitivity. Our data indicate that LSD1 is a functional alternative subunit of the SIN3A/HDAC complex, providing a molecular basis for the interplay of histone demethylation and deacetylation in chromatin remodelling, and suggest that the LSD1/SIN3A/HDAC complex could be a target for breast cancer therapeutic strategies.

PHD finger protein 1 (PHF1) is a novel reader for histone H4R3 symmetric dimethylation and coordinates with PRMT5-WDR77/CRL4B complex to promote tumorigenesis.

Histone post-translational modifications regulate chromatin structure and function largely through interactions with effector proteins that often contain multiple histone-binding domains. PHF1 [plant homeodomain (PHD) finger protein 1], which contains two kinds of histone reader modules, a Tudor domain and two PHD fingers, is an essential factor for epigenetic regulation and genome maintenance. While significant progress has been made in characterizing the function of the Tudor domain, the roles of the two PHD fingers are poorly defined. Here, we demonstrated that the N-terminal PHD finger of PHF1 recognizes symmetric dimethylation of H4R3 (H4R3me2s) catalyzed by PRMT5-WDR77. However, the C-terminal PHD finger of PHF1, instead of binding to modified histones, directly interacts with DDB1, the main component of the CUL4B-Ring E3 ligase complex (CRL4B), which is responsible for H2AK119 mono-ubiquitination (H2AK119ub1). We showed that PHF1, PRMT5-WDR77, and CRL4B reciprocally interact with one another and collaborate as a functional unit. Genome-wide analysis of PHF1/PRMT5/CUL4B targets identified a cohort of genes including E-cadherin and FBXW7, which are critically involved in cell growth and migration. We demonstrated that PHF1 promotes cell proliferation, invasion, and tumorigenesis in vivo and in vitro and found that its expression is markedly upregulated in a variety of human cancers. Our data identified a new reader for H4R3me2s and provided a molecular basis for the functional interplay between histone arginine methylation and ubiquitination. The results also indicated that PHF1 is a key factor in cancer progression, supporting the pursuit of PHF1 as a target for cancer therapy.

The Homeotic Protein SIX3 Suppresses Carcinogenesis and Metastasis through Recruiting the LSD1/NuRD(MTA3) Complex.

The homeodomain transcription factor SIX3 was recently reported to be a negative regulator of the Wnt pathway and has an emerging role in cancer. However, how SIX3 contributes to tumorigenesis and metastasis is poorly understood. METHODS: We employed affinity purification and mass spectrometry (MS) to identify the proteins physically associated with SIX3. Genome-wide analysis of the SIX3/LSD1/NuRD(MTA3) complex using a chromatin immunoprecipitation-on-chip approach identified a cohort of target genes including WNT1 and FOXC2, which are critically involved in cell proliferation and epithelial-to-mesenchymal transition. Also, we used flow cytometry, growth curve analysis, EdU incorporation assay, colony formation assays, trans-well invasion assays, immunohistochemical staining and in vivo bioluminescence assay to investigate the function of SIX3 in tumorigenesis. RESULTS: We demonstrate that the SIX3/LSD1/NuRD(MTA3) complex inhibits carcinogenesis in breast cancer cells and suppresses metastasis in breast cancer. SIX3 expression is downregulated in various human cancers and high SIX3 is correlated with improved prognosis. CONCLUSION: Our study revealed an important mechanistic link between the loss of function of SIX3 and tumor progression, identified a molecular basis for the opposing actions of MTA1 and MTA3, and may provide new potential prognostic indicators and targets for cancer therapy.

MicroRNA-15b Suppresses Th17 Differentiation and Is Associated with Pathogenesis of Multiple Sclerosis by Targeting O-GlcNAc Transferase.

IL-17-producing Th17 cells have gradually become considered as key factors in the pathogenesis of many autoimmune diseases, including multiple sclerosis (MS). Although the involvement of certain microRNAs in the development of MS has been reported, their role in Th17-driven autoimmunity is still poorly understood. In this study, we identified microRNA (miR)-15b as an important factor in Th17-associated effects and determined that the expression of miR-15b is significantly downregulated in MS patients and in mice with experimental autoimmune encephalomyelitis. Overexpression of miR-15b alleviated experimental autoimmune encephalomyelitis, whereas knockdown of miR-15b aggravated it. We demonstrated that miR-15b suppressed Th17 differentiation both in vivo and in vitro. We also found that O-linked N-acetylglucosamine transferase is a potential target of miR-15b, enabling it to affect the transcriptional regulation of retinoic acid-related orphan receptor γT through O-linked N-acetylglucosamine glycosylation of NF-κB. These results contribute to the importance of miR-15b in Th17 differentiation and the pathogenesis of MS.

Everolimus (RAD001) ameliorates vascular cognitive impairment by regulating microglial function via the mTORC1 signaling pathway.

Vascular dementia (VaD) is a widely prevalent and devastating disease. Despite the tremendous complexity that limits understanding of the pathophysiology of VaD, microglial dysfunction has been attributed, in part, to immune microenviroment disorder and finally leads to cognitive deficits. Considered the mammalian target of rapamycin complex 1 (mTORC1) is a key player in regulation of glial function, our work focused on whether the mTOR inhibitor everolimus (RAD001) could overcome the destructive microglial function, change the phenotype and ameliorate cognitive decline induced by chronic cerebral hypoperfusion. Strikingly, the results suggest that inhibition of the mTORC1 activity by RAD001 ameliorates VaD by restoring microglia's M1/M2 balance. Therefore, RAD001 may have promise as a therapy for VaD disease.

CRL4B catalyzes H2AK119 monoubiquitination and coordinates with PRC2 to promote tumorigenesis.

We reported that Cullin4B-Ring E3 ligase complex (CRL4B) is physically associated with Polycomb-repressive complex 2 (PRC2). We showed that CRL4B possesses an intrinsic transcription repressive activity by promoting H2AK119 monoubiquitination. Ablation of Cul4b or depletion of CUL4B, the main component of CRL4B, resulted in loss of not only H2AK119 monoubiquitination but also H3K27 trimethylation, leading to derepression of target genes that are critically involved in cell growth and migration. We demonstrated that CUL4B promotes cell proliferation, invasion, and tumorigenesis in vitro and in vivo and found that its expression is markedly upregulated in various human cancers. Our data indicate that CUL4B promotes tumorigenesis, supporting the pursuit of CUL4B as a target for cancer therapy.

Time-dependent density functional theory study on the electronic excited-state geometric structure, infrared spectra, and hydrogen bonding of a doubly hydrogen-bonded complex.

The geometric structures and infrared (IR) spectra in the electronically excited state of a novel doubly hydrogen-bonded complex formed by fluorenone and alcohols, which has been observed by IR spectra in experimental study, are investigated by the time-dependent density functional theory (TDDFT) method. The geometric structures and IR spectra in both ground state and the S(1) state of this doubly hydrogen-bonded FN-2MeOH complex are calculated using the DFT and TDDFT methods, respectively. Two intermolecular hydrogen bonds are formed between FN and methanol molecules in the doubly hydrogen-bonded FN-2MeOH complex. Moreover, the formation of the second intermolecular hydrogen bond can make the first intermolecular hydrogen bond become slightly weak. Furthermore, it is confirmed that the spectral shoulder at around 1700 cm(-1) observed in the IR spectra should be assigned as the doubly hydrogen-bonded FN-2MeOH complex from our calculated results. The electronic excited-state hydrogen bonding dynamics is also studied by monitoring some vibraitonal modes related to the formation of hydrogen bonds in different electronic states. As a result, both the two intermolecular hydrogen bonds are significantly strengthened in the S(1) state of the doubly hydrogen-bonded FN-2MeOH complex. The hydrogen bond strengthening in the electronically excited state is similar to the previous study on the singly hydrogen-bonded FN-MeOH complex and play important role on the photophysics of fluorenone in solutions.