Gene transcription is coordinately regulated by multiple transcription factors. However, a systematic approach is still lacking to identify co-regulators for transcription factors. Here, we performed ...ChIP-Seq analysis and predicted the regulators for p53-mediated transcription process, from which we confirmed the roles of GLIS2, MAZ and MEF2A in regulating p53 target genes. We revealed that GLIS2 selectively regulates the transcription of PUMA but not p21. GLIS2 deficiency caused the elevation of H3K27ac and p53 binding on the PUMA enhancer, and promoted PUMA expression. It increased the rate of apoptosis, but not cell cycle. Moreover, GLIS2 represses H3K27ac level on enhancers, regulates the gene expression related with focal adhesion and promotes cell migration, through inhibiting p300. Big data analysis supports GLIS2 as an oncogene in colon cancer, and perhaps other cancers. Taken together, we have predicted candidates for p53 transcriptional regulators, and provided evidence for GLIS2 as an oncogene through repressing enhancer activation.
Unlike other members of the polycomb group protein family, EZH1 has been shown to positively associate with active transcription on a genome-wide scale. However, the underlying mechanism for this ...behavior still remains elusive. Here, we report that EZH1 physically interacts with UXT, a small chaperon-like transcription co-activator. UXT specifically interacts with EZH1 and SUZ12, but not EED. Similar to upon knockdown of UXT, knockdown of EZH1 or SUZ12 through RNA interference in the cell impairs the transcriptional activation of nuclear factor (NF)-κB target genes induced by TNFα. EZH1 deficiency also increases TNFα-induced cell death. Interestingly, chromatin immunoprecipitation and the following next-generation sequencing analysis show that H3K27 mono-, di- and tri-methylation on NF-κB target genes are not affected in EZH1- or UXT-deficient cells. EZH1 also does not affect the translocation of the p65 subunit of NF-κB (also known as RELA) from the cytosol to the nucleus. Instead, EZH1 and SUZ12 regulate the recruitment of p65 and RNA Pol II to target genes. Taken together, our study shows that EZH1 and SUZ12 act as positive regulators for NF-κB signaling and demonstrates that EZH1, SUZ12 and UXT work synergistically to regulate pathway activation in the nucleus.
Epigenetic regulation has emerged to be the critical steps for tumorigenesis and metastasis. Multiple histone methyltransferase and demethylase have been implicated as tumor suppressors or oncogenes ...recently. But the key epigenomic events in cancer cell transformation still remain poorly understood.
A breast cancer transformation model was established via stably expressing three oncogenes in primary breast epithelial cells. Chromatin immunoprecipitation followed by the next-generation sequencing of histone methylations was performed to determine epigenetic events during transformation. Western blot, quantitative RT-PCR, and immunostaining were used to determine gene expression in cells and tissues.
Histones H3K9me2 and me3, two repressive marks of transcription, decrease in in vitro breast cancer cell model and in vivo clinical tissues. A survey of enzymes related with H3K9 methylation indicated that KDM3A/JMJD1A, a demethylase for H3K9me1 and me2, gradually increases during cancer transformation and is elevated in patient tissues. KDM3A/JMJD1A deficiency impairs the growth of tumors in nude mice and transformed cell lines. Genome-wide ChIP-seq analysis reveals that the boundaries of decreased H3K9me2 large organized chromatin K9 modifications (LOCKs) are enriched with cancer-related genes, such as MYC and PAX3. Further studies show that KDM3A/JMJD1A directly binds to these oncogenes and regulates their transcription by removing H3K9me2 mark.
Our study demonstrates reduction of histones H3K9 me2 and me3, and elevation of KDM3A/JMJD1A as important events for breast cancer, and illustrates the dynamic epigenomic mechanisms during breast cancer transformation.
Intrahepatic cholangiocarcinoma (ICC) has limited therapeutic options and a dismal prognosis. Adding blockade of the anti-programmed cell death protein (PD)-1 pathway to gemcitabine/cisplatin ...chemotherapy has recently shown efficacy in biliary tract cancers but with low response rates. Here, we studied the effects of anti-cytotoxic T lymphocyte antigen (CTLA)-4 when combined with anti-PD-1 and gemcitabine/cisplatin in orthotopic murine models of ICC. This combination therapy led to substantial survival benefits and reduction of morbidity in two aggressive ICC models that were resistant to immunotherapy alone. Gemcitabine/cisplatin treatment increased tumor-infiltrating lymphocytes and normalized the ICC vessels and, when combined with dual CTLA-4/PD-1 blockade, increased the number of activated CD8+Cxcr3+IFNγ+ T cells. CD8+ T cells were necessary for the therapeutic benefit because the efficacy was compromised when CD8+ T cells were depleted. Expression of Cxcr3 on CD8+ T cells is necessary and sufficient because CD8+ T cells from Cxcr3+/+ but not Cxcr3-/- mice rescued efficacy in T cell‒deficient mice. Finally, rational scheduling of anti-CTLA-4 "priming" with chemotherapy followed by anti-PD-1 therapy achieved equivalent efficacy with reduced overall drug exposure. These data suggest that this combination approach should be clinically tested to overcome resistance to current therapies in ICC patients.
Sexual and gender minority (SGM) individuals have an increased risk of poor health outcomes, in part due to knowledge and training gaps in health care education. This study sought to evaluate the ...knowledge, attitudes, and practice behaviors of various health care role groups within radiation oncology toward SGM patients.
A 38-item web-based survey was emailed to 1045 staff across 2 large radiation oncology departments. The survey assessed demographics, attitudes, knowledge, and practice behaviors. χ2 tests were performed to explore differences in survey responses by age, political affiliation, religious identity, year since graduation, and role groups. One-way analysis of variance tests were conducted to determine differences between respondents’ confidence in knowledge and performance on the knowledge section of the survey. Thematic analysis was applied to the open discussion section.
Of the 223 respondents, 103 clinicians (physicians/advanced practice providers/nurses) and 120 nonclinicians (administrative staff, medical assistants, and other nonmedical staff) participated in the survey (21.3% response rate): 72.6% answered the knowledge questions; 93.5% stated they were comfortable treating sexual minorities, or lesbian, gay, bisexual, and queer + patients; 88% indicated comfort in treating transgender patients; 36.6% stated they were confident in their knowledge of the health needs of transgender patients; and 50.3% expressed confidence in treating lesbian, gay, bisexual, and queer + patients. Fewer nonclinicians than clinicians thought that gender identity, sexual orientation, and sex assigned at birth were important to provide the best care (P < .05). The open comments section identified key themes, including the belief that current educational tools are not helpful, desire for more educational formats (lectures, case-based learning, seminars), and an overall interest in SGM health education.
Most staff feel comfortable in treating SGM patients but are less confident in the distinct needs of this population. Knowledge gaps persist for both clinicians and nonclinicians, indicating a need for further training specific to oncology care.
Epigenetic marks are critical regulators of chromatin and gene activity. Their roles in normal physiology and disease states, including cancer development, still remain elusive. Herein, the ...epigenomic change of H3K9me3, as well as its potential impacts on gene activity and genome stability, was investigated in an
breast cancer transformation model.
The global H3K9me3 level was studied with western blotting. The distribution of H3K9me3 on chromatin and gene expression was studied with ChIP-Seq and RNA-Seq, respectively.
The global H3K9me3 level decreases during transformation and its distribution on chromatin is reprogrammed. By combining with TCGA data, we identified 67 candidate oncogenes, among which five genes are totally novel. Our analysis further links H3K9me3 with transposon activity, and suggests H3K9me3 reduction increases the cell's sensitivity to DNA damage reagents.
H3K9me3 reduction is possibly related with breast cancer transformation by regulating gene expression and chromatin stability during transformation.
Although the overall incidence of tuberculosis in underdeveloped areas has increased in recent years, esophageal tuberculosis (ET) is still rare. Intestinal tuberculosis (ITB) is relatively more ...common, but there are few reports of ET complicated with ITB. We report a case of secondary ET complicated with ITB in a previously healthy patient.
A 27-year-old female was hospitalized for progressive dysphagia, retrosternal pain, acid regurgitation, belching, heartburn, and nausea. Upper gastrointestinal endoscopy showed a mid-esophageal ulcerative hyperplastic lesion. Endoscopic ultrasonography showed a homogeneous hypoechoic lesion, with adjacent enlarged lymph nodes. Biopsy histopathology showed inflammatory exudation, exfoliated epithelial cells and interstitial granulation tissue proliferation. Colonoscopy revealed a rat-bite ulcer in the terminal ileum and a superficial ulcer in the ascending colon, near the ileocecal region. The ileum lesion biopsy showed focal granulomas with caseous necrosis. Polymerase chain reaction for
was positive in the esophageal and ileum lesion biopsies. The T-cell spot tuberculosis test was also positive. The patient was diagnosed with secondary ET infiltrated by mediastinal lymphadenopathy and complicated with ITB, possibly from the
-infected esophageal lesion. After 2 mo of anti-tuberculosis therapy, her symptoms improved significantly, and upper gastrointestinal endoscopy showed healing ulcers.
When dysphagia or odynophagia occurs in patients at high-risk for tuberculosis, ET should be considered.
Abstract Purpose: Ependymoma (EPN) is a common type of brain tumor in children and is often resistant to available cytotoxic therapies. Molecular profiling studies have led to a better understanding ...of unique EPN subtypes and revealed a critical role of EPHB2. However, the immune system's role in tumor progression and treatment response remains poorly understood. New treatments for EPN are desperately needed and should be developed in a molecular subtype-specific fashion. Experimental Design: We developed a syngeneic mouse model using subtype-specific EPHB2-driven genetically engineered EPN tumor cells. Druggable targets were identified by matching transcriptomic signatures with the target spectrum of FDA-approved drugs. After identifying dasatinib as a potentially effective agent, we measured the changes in the immune microenvironment during EPN growth and after dasatinib treatment. Results: Transcriptomic profiling of EPHB2-driven EPN and analysis of a human EPN dataset revealed multiple protein kinases as potential druggable targets. We found that the multikinase inhibitor dasatinib potently inhibited the growth of EPN both in vitro and in vivo, mainly through blocking EPHB2 and ABL1 signaling. We found an increased frequency of immunosuppressive M2-like tumor-associated macrophages (TAMs), which proportionally increased with tumor size during tumor progression. However, treatment with dasatinib reprogrammed the EPN immune microenvironment by polarizing the TAMs toward an anti-tumor M1-like phenotype and increasing CD8 T cell activation. Furthermore, dasatinib treatment induced complete regression of established EPN tumors in 78% of the animals and protected survivors against tumor recurrence. Depletion of CD8 T cells compromised the durability of EPN responses and reduced overall survival. Conclusions: These data indicate that dasatinib may be an effective therapy for EPHB2-driven molecular subgroup of EPNs by activating the anti-tumor immune response and support further investigations of dasatinib in clinical trials. Citation Format: Taylor P. Uccello, Jun Ren, Zohreh Amoozgar, Yuhui Zhao, Pin-Ji Lei, William W. Ho, Sylvie Roberge, Peigen Huang, Dan G. Duda, Lei Xu, Rakesh K. Jain. Targeting EPHB2/ABL1 restores anti-tumor immunity in a preclinical model of ependymoma abstract. In: Proceedings of the AACR Special Conference on Brain Cancer; 2023 Oct 19-22; Minneapolis, Minnesota. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_1):Abstract nr PR-004.
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