In summary, diffuse large B-cell lymphoma patients with either MYC/BCL6 rearrangements or MYC/BCL6 co-expression did not always have poorer prognosis; MYC expression levels should be evaluated simultaneously; and double-hit B-cell lymphoma needs to be refined based on the specific genetic abnormalities present in these tumors.
Taken together, our findings support a model in which c-MYC-driven transcriptional events, combined with epigenetic mechanisms, direct and regulate the expression of ABC genes with possible implications in tumor malignancy and drug efflux in CML.
907-916) demonstrate an essential role for endogenous Myc proteins in maintaining the tumor microenvironment, providing an unexpected molecular explanation for addiction to Myc.
Furthermore, when maintained under hypoxic conditions, these MYC-amplified tumors demonstrated increased viability compared to non-amplified tumors within the same subgroup.
A significant increase in the mRNA levels of neuron-specific enolase was detected in BEAS-2B cells containing both the c-raf-1 and c-myc genes and derived tumor cell lines.
We and others have identified activation of MYC as a driver of susceptibility to Aurora kinase inhibition in SCLC cells and tumors that translates into a therapeutic option for the targeted treatment of MYC-driven SCLC.
The Fas/Fas ligand/caspase death-signaling pathway, Bcl-2 protein family/mitochondria, the tumor suppressive gene p53, and the proto-oncogene c-myc may be activated in atherosclerotic lesions and mediate vascular apoptosis during the development of atherosclerosis.
One possible reason is that the increased expression of the c-myc protein is not sufficient alone to promote proliferation and malignant transformation in these types of tumors.
Overexpression of epidermal growth factor receptor (EGF-R), K-ras gene mutations and c-myc gene amplification were studied in tumor and normal lung tissues from 100 patients with non-small cell lung cancer.
Subgroups of 4-5 mice were sacrificed at 3, 6 and 24 h after therapy so that tumors could be examined for poly(ADP-ribose) polymerase (PARP) and DNA ladder evidence for apoptosis and for BCL2, p53, p21, GADD45, TGF-beta 1 and c-MYC gene and protein expression.
Inhibition of BRD4 decreased bladder cancer cell proliferation concomitantly with the accumulation of cell apoptosis in vitro and suppressed tumor growth in vivo We further found that suppression of BRD4 decreased the mRNA and protein levels of EZH2, which was reversed by ectopic expression of C-MYC In particular, individual silencing of BRD4 using shRNA or the BET inhibitor JQ1 strikingly diminished the recruitment of C-MYC to EZH2 promoter in bladder cancer.
The c-myc gene copy number was higher than in leukocytes and normal bladder mucosa in 14 of 40 tumors, but only 3 among these showed a more than 4-fold increase indicative of gene amplification.
Rates of tumor growth inhibition showed good correlation with the behavior of pharmacodynamic biomarkers, such as Axin2 accumulation and MYC downregulation.
Focal c-MYC expression resulted in mild pathology, but prostate-specific deletion of a single allele of the Pten tumor suppressor gene cooperated with c-MYC to induce high grade prostatic intraepithelial neoplasia (HGPIN)/cancer lesions.
Mechanistically, MYC binding is enriched at neuroendocrine genes in mouse tumor cells and loss of MYC reduces ductal-neuroendocrine lineage heterogeneity, while deregulated MYC expression in KRAS mutant mice increases this phenotype.
Sirtuin 6, a member of sirtuin family, is generally regarded as a tumor suppressor as it participates in suppressing hypoxia-inducible factor 1α and MYC transcription activity by deacetylating H3K9 (histone H3 lysine 9) and H3K56 (histone H3 lysine) at promoters of target genes, leading to the aerobic glycolysis inhibition and cell growth suppression.
These findings establish MYC repression as a mechanism for ZFHX3's tumor suppressor activity and ZFHX3 as an indispensable factor for ERβ's tumor suppressor activity in prostate cancer cells.