Expression of B7-H6 in chronic myeloid leukemia and its clinical significance.
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ABSTRACT:
SUBMITTER: Cao Y
PROVIDER: S-EPMC6945099 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:B7-H6, a ligand for the NK activating receptor NKp30, has been identified as a biomarker of poor prognosis in several solid cancers. However, little is known about the role of B7-H6 and the mechanisms that control its expression in acute myeloid leukemia (AML). Epigenome modulation, including epigenomic reader dysregulation, is one of the hallmarks of AML. Bromodomain-containing protein 4 (BRD4), the best-known member of the BET family of epigenetic readers, is overexpressed in AML cells and regulates the transcription of genes involved in the pathogenesis of AML, as MYC oncogene. Here, we analyze the role of BRD4 in regulating B7-H6 in AML cells. Results demonstrated that the specific inhibition of BRD4 drastically reduces the expression of B7-H6 in AML cells. Histone acetylation mediated by CBP30/P300 facilitates the binding of BRD4 to the B7-H6 promoter, which recruits the P-TEFb elongation factor that phosphorylates RNA polymerase II, thereby activating B7-H6 transcription. BRD4 also co-bounded with JMJD6 at the distal enhancer of the B7-H6 gene. Metabolic modulation with metformin modifies the acetylation pattern in the B7-H6 promoter, impairing BRD4 binding, thereby inhibiting B7-H6 expression. B7-H6 knockdown induces the apoptosis in HEL-R cell line. Moreover, a high level of B7-H6 expression in AML patients is related to increased BRD4 levels, myelodysplastic-derived AML, and del5q, the two latter being associated with poor prognosis. Our data show that BRD4 is a positive regulator of the pro-tumorigenic molecule B7-H6 and that the blockage of the B7-H6 is a potential therapeutic target for the treatment of AML.
| S-EPMC8007156 | biostudies-literature
Project description:B7 homolog 6 (B7-H6), a member of the B7 family, is as a cell-surface ligand for natural cytotoxicity triggering receptor 3, which is expressed on natural killer cells. It has previously been reported that B7-H6 is undetectable in normal human tissues but is expressed on tumor cells. However, there are few studies focusing on the clinical significance of B7-H6 expression in human carcinoma, with the exception of three studies on ovarian, lung and gastric cancer. The present study investigated the expression of B7-H6 protein in pathologic tissue samples from 305 patients with breast cancer using immunohistochemistry. A high B7-H6 expression level was identified in tissues from 32.13% of patients with breast cancer. These patients were revealed to also exhibit a high expression level of human epidermal growth factor receptor 2, a shorter survival time and a higher rate of lymph node metastasis. Furthermore, the expression level of B7-H6 was not associated with patient age, breast cancer subtype, tumor size, tumor location or estrogen receptor expression. The results of the present study revealed that higher B7-H6 expression level in breast cancer tissues was positively associated with tumor progression. This indicates that B7-H6 is associated with the progression and immunoevasion of human breast cancer; however, the molecular mechanisms underlying this potential effect require further investigation.
| S-EPMC5530087 | biostudies-other
Project description:Costimulatory molecules are essential regulators of the immunological synapse and enable the fine-tuning of the immune response. These mechanisms are subverted by cancer cells to evade immunosurveillance. The B7 family of costimulatory molecules comprises several ligands that may contribute to immunoescape. B7-H3 [B7-homolog 3 or CD276] remains poorly investigated in hematological malignancies. To determine the role B7-H3, we analyzed the expression of this molecule in blast cells from a cohort of 111 acute myeloid leukemia (AML) patients. B7-H3 was expressed in blast cells with a mean fluorescence intensity ratio >3 in 30 (27%) of the 111 patients. B7-H3 expression was higher in the M3 and M5 FAB subtypes and in cases with mutated NPM1 and wild type CEBPA. There were no significant differences found for the FLT3-ITD or cytogenetic risk groups. The complete remission (CR) rate between the 17 B7-H3-positive and 58 negative patients who were treated intensively was not different. The event free survival was longer in B7-H3-positive patients (P = 0.014), and there was a trend toward better overall survival. However, this difference was not statistically significant (P = 0.053). In conclusion, B7-H3 is one of the most strongly expressed B7-family molecules in AML and merits further investigation.
| S-EPMC5123710 | biostudies-literature
Project description:BackgroundB7 family molecules affect both immune responses and cancer progression via immunological and non-immunological pathways. However, the specific expression and prognostic value of B7 members in acute myeloid leukemia (AML) remains unclear; hence, an investigation using online bioinformatics databases is required.MethodsIn this study, we explored the expression of B7 molecules using the ONCOMINE, Gene Expression Profiling Interactive Analysis 2 (GEPIA2), and UALCAN databases, while the prognostic value of B7 molecules in AML was analyzed using the LinkedOmics, GEPIA2, UALCAN, and TCGAportal databases. Additionally, genetic alteration and gene co-expression analysis of the B7 family was performed via the cBioPortal and LinkedOmics databases, while functional and pathway enrichment analyses were conducted using the Metascape databases for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses.ResultsThe message RNA (mRNA) levels of B7 family members varied in AML patients, and aberrant highly expressed B7 members were correlated with poor prognosis in AML, including B7.1, B7-DC, B7-H3, B7-H5, and B7-H7. B7-H6 acted as a protective molecule for overall survival (OS), while B7-H1 overexpression was inclined to predict poor prognosis. B7 family gene alteration occurred frequently in AML, and the altered B7 group seemed to exhibit a trend towards worse OS. The co-expression genes and relative signaling pathways of the B7 family might be involved in oncogenesis and be associated with prognosis in AML.ConclusionsOur study showed that aberrantly expressed B7 family molecules affected the prognosis of AML patients, and thus, could be promising prognostic biomarkers and new therapeutic targets.
| S-EPMC8576715 | biostudies-literature
Project description:B7-H6, a new member of B7-family ligand, also known as NCR3LG1, plays an important role in NK cells mediated immune responses. Many studies have shown that it is highly expressed in various human cancers, and its expression levels are significantly associated with cancer patients' clinicopathological parameters and postoperative prognoses. But, still the exact role of B7-H6 expression in human glioma remains elusive. In the present study, we have characterized the B7-H6 expression in the human glioma tissues as well as glioma cell lines, U87 and U251. We observed that B7-H6 was highly expressed in the human glioma tissues, and its expression was significantly associated with cancer progression. By using the RNA interference technology, we successfully ablated B7-H6 expression in human glioma cell lines to further study its contribution towards various biological features of this malignancy. Our study identified that the B7-H6 knockdown in U87 and U251 glioma cells significantly suppressed cell proliferation, migration, invasion, and enhanced apoptosis along with induction of cell cycle arrest. It thus suggested that B7-H6 play an important role in the regulation of the biological behavior of these glioma cells. However, the detailed mechanism of B7-H6 mediated regulation of glioma cancer cell transformation and its prognostic value merits further investigation.
| S-EPMC5514920 | biostudies-literature
Project description:BackgroundThe interaction between activating receptor NKp30 and its major tumor ligand B7-H6 is important for NK cell-mediated tumor rejection. However, the regulation of B7-H6 by tumor therapeutics remains largely unknown. In this study, we investigated the regulation of B7-H6 by all-trans retinoic acid (atRA), a terminal differentiation inducer of tumor cells that is extensively used for clinical leukemia therapy.MethodsWe investigated the role of NKp30:B7-H6 axis in NK cell-mediated tumor lysis against leukemia cells and the influence of atRA treatment on the cytotoxicity of NK cells using NK cell lines (NK92 and NKG) and leukemia cell lines (U-937 and THP-1). We evaluated the effect of atRA treatment on the expression of B7-H6 using real-time PCR, flow cytometry and western blotting. We used CRISPR/Cas9 to knockdown B7-H6 expression and siRNA to knockdown c-Myc in U-937 cells to evaluate the role of B7-H6 and c-Myc in atRA-induced tumor resistance against NK cells.ResultsNK cell-mediated U-937 cell lysis was mainly dependent on NKp30/B7-H6 interaction. Blockade of B7-H6 by monoclonal antibody significantly impaired NK cytotoxicity. atRA treatment induced U-937 resistance to NK cell cytotoxicity by reducing B7-H6 expression, and showed no effect on NK cytotoxicity against B7-H6 knockdown U-937 cells. Epigenetic modifications, such as DNA methylation and histone deacetylase (HDAC), were not responsible for atRA-mediated B7-H6 down-regulation as inhibitors of these pathways could not restore B7-H6 mRNA expression. On the other hand, atRA treatment reduced c-Myc expression, which in turn inhibited the transcription of B7-H6 on leukemia cells.ConclusionatRA treatment promotes tumor cell resistance against NK cell-mediated lysis by down-regulating B7-H6 expression via the c-Myc signaling pathway, suggesting that more attention needs to be paid to the immunological adverse effects in the clinical use of atRA treatment.
| S-EPMC7819554 | biostudies-literature
Project description:ABCB1 is a member of the ATP binding cassette transporter family and high ABCB1 activity is considered as a poor prognostic factor in acute myeloid leukemia (AML) treated with intensive chemotherapy, its direct relation with drug resistance remains unclear. We evaluated ABCB1 activity in relation with clinical parameters and treatment response to standard chemotherapy in 321 patients with de novo AML. We assessed multiple clinical relationships of ABCB1 activity-ex vivo drug resistance, gene expression, and the ABCB1 inhibitor quinine were evaluated. ABCB1 activity was observed in 58% of AML and was linked to low white blood cell count, high expression of CD34, absence of FLT3-ITD, and absence of mutant NPM1. Moreover, ABCB1 activity was associated with worse overall- and event-free survival. However, ABCB1 activity did not directly lead to ex vivo drug resistance to anthracyclines. We found that ABCB1 was highly correlated with gene expressions of BAALC, CD34, CD200, and CD7, indicating that ABCB1 expression maybe a passenger characteristic of high-risk AML. Furthermore, ABCB1 was inversely correlated to HOX cluster genes and CD33. Thus, low ABCB1 AML patients benefited specifically from anti-CD33 treatment by gemtuzumab ozogamicin in addition to standard chemotherapy. We showed prognostic importance of ABCB1 gene expression, protein expression, and activity. Furthermore, ABCB1 was not directly linked to drug resistance, ABCB1 inhibition did not improve outcome of high ABCB1 AML patients and thus high ABCB1 may represent a passenger characteristic of high-risk AML.
| S-EPMC6770064 | biostudies-literature
Project description:BackgroundChronic myeloid leukemia (CML) is a myeloproliferative neoplasm where pathogenesis is based on the oncoprotein termed BCR-ABL1.1 TET2 initiates DNA demethylation and is frequently mutated in hematological malignancies, including CML. The relation between TET2 acquisition and CML transformation and/or imatinib resistance is needed to be investigated.2.AimTo evaluate Ten Eleven Translocation 2 gene (TET2) single nucleotide polymorphism (SNP) (rs2454206, rs34402524, rs61744960) in chronic myeloid leukemia (CML) in relation to the disease prognostic criteria.Materials & methodThe study included 84 subjects; 54 CML in chronic phase and 30 healthy subjects as control group matched for age and sex. Routine investigations, including CBC, bone marrow aspiration, biochemical investigations, and molecular study, were performed in CML patients to identify the disease stage. DNA extraction and SNP assay for TET2 gene polymorphism were done using (Thermo-Fisher predesigned SNP, USA) PCR prism 7500.ResultsThe mean age was 45.98±15.7 yrs in CML patients and 39.3±6.587 yrs in the control group (p>0.05). TET2 SNP rs 34402524 was either heterozygous or homozygous in CML (48%, 46.2% respectively) but was mainly homozygous among control (80%) group (p=0.012). TET2 SNP rs 2454206 wild type within CML was detected in 65.4% of patients and in controls was 63.3% (p=0.046). TET2 SNP rs 61744960 showed a homozygous pattern among all groups (CML and control) (p=0.528). TET2 SNP in CML cases did not alter the prognostic criteria as no statistical significance was noted (p>0.05) yet, it was significantly related to spleen size in rs 34402524 where the homozygous group had larger spleen size and higher BCR-ABL1 levels six months after starting TKIs (p<0.05).Conclusions/recommendationTET2 SNP is common among Egyptian chronic myeloid leukemia. TET2 SNP rs 3442524 was associated with larger spleen size and higher BCR-ABL1 levels after six months of starting TKIs suggesting disease progression.
| S-EPMC6951353 | biostudies-literature
Project description:Background:B7-H6 is a novel co-stimulatory ligand that is detected in most malignancies. However, the significance of B7-H6 in small cell lung cancer (SCLC) remains unknown. Methods:B7-H6 expression was analyzed by immunohistochemistry (IHC) in 103 collected SCLC samples, and its association with clinicopathological characteristics and prognosis was analyzed. The 2-year survival rates were also investigated. Results:B7-H6-positive staining was detected in 58 (56.31%) SCLC cases, and found to be localized mainly in the intracellular space of SCLC. Weak staining in lung tissues was observed in 4 (8%) cases. B7-H6 positive staining was significantly related to tumor-node-metastasis stage (P=0.028), age (P=0.001), and distant metastasis (P=0.033), whereas there was no association with smoking status, sex, mass size, limited-stage SCLC/extensive-stage SCLC, Karnofsky performance status, or nodal metastasis status. The 2-year survival rates showed that there were more patients whose survival was shorter than 2 years in the B7-H6-positive group compared with the B7-H6-negative group (P=0.042). Conclusions:Our findings suggest that B7-H6 is involved in early-stage SCLC and could serve as an early marker to predict human SCLC progression and distant metastasis. B7-H6 may be a valuable therapeutic target with potential clinical applications in the future.
| S-EPMC7290544 | biostudies-literature
Project description:The role of B7-H3 in acute myeloid leukemia (AML) is not fully understood. Two previous studies investigating its expression and significances in AML are partially different. In this study, we aimed to systematically characterize the genomic and immune landscape in AML patients with altered B7-H3 expression using multi-omics data in the public domain. We found significantly increased B7-H3 expression in AML compared to either other hematological malignancies or healthy controls. Clinically, high B7-H3 expression was associated with old age, TP53 mutations, wild-type WT1 and CEBPA, and the M3 and M5 FAB subtypes. Moreover, we observed that increased B7-H3 expression correlated significantly with a poor outcome of AML patients in four independent datasets. Gene set enrichment analysis (GSEA) revealed the enrichment of the "EMT" oncogenic gene signatures in high B7-H3 expressers. Further investigation suggested that B7-H3 was more likely to be associated with immune-suppressive cells (macrophages, neutrophils, dendritic cells, and Th17 cells). B7-H3 was also positively associated with a number of checkpoint genes, such as VISTA (B7-H5), CD80 (B7-1), CD86 (B7-2), and CD70. In summary, we uncovered distinct genomic and immunologic features associated with B7-H3 expression in AML. This may lead to a better understanding of the molecular mechanisms underlying B7-H3 dysregulation in AML and to the development of novel therapeutic strategies.
| S-EPMC8559480 | biostudies-literature