scholarly journals Single molecule imaging reveals cFos is capable of binding to and diffusing on DNA tightropes independently of cJun

2020 ◽  
Author(s):  
James T. Leech ◽  
Nicola A. Don ◽  
Jody M. Mason ◽  
Neil M. Kad

AbstractAP-1 proteins are members of the basic leucine zipper (bZIP) protein family of dimeric transcription factors, responsible for controlling many integral cellular processes. These proteins form dimers with each other, and their aberrant expression can lead to a number of cancer types. The oncogenic transcription factor AP-1 binds its target TRE site (5’TCA[G/C]TGA), however the physical mechanism of how this is achieved is not understood. Such an understanding is essential to know how these proteins function, and could offer the potential to uncover new drug targets. The archetypal AP-1 complex is formed by cFos and cJun, which heterodimerise via their bZIP domains. Here, we set out to investigate how these proteins interact with DNA using a real-time single molecule fluorescence imaging approach. Using DNA tightropes as a substrate, we determine that the AP-1 bZIP dimers cJun:cFos and cJun:cJun rapidly scan DNA using a 1D diffusional search with an average diffusion constant of 0.14 µm2s-1 and 0.26 µm2s-1 respectively. Remarkably, we also found that cFos was able to bind to and diffuse on DNA (0.29 µm2s-1) both as a monomer and homodimer. Periods of diffusion were punctuated by pauses, suggesting a mechanism for how AP-1 may rapidly find its target sites on DNA. Taken together the results we have obtained indicate a considerably more complex and graded interaction between cFos, cJun and DNA than has been reported previously.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e16211-e16211
Author(s):  
Bin Wu ◽  
Aijun Li ◽  
Keji Chen ◽  
Lin Chen ◽  
Qin Zhang ◽  
...  

e16211 Background: Nuclear factor E2-related factor-2 (NFE2L2) gene encodes a transcription factor which is a member of basic leucine zipper (bZIP) proteins family. Overexpression of NFE2L2 lead to cell proliferation and promoted tumor metastasis. Previous report indicated that NFE2L2 mutation (NFE2L2-MT) was an independent poor prognostic factor in esophageal squamous cell carcinoma (ESCC). However, the correlation between NFE2L2 mutation and pan-cancer types of TMB, MSI, and PD-L1 expression is unclear. Methods: TMB analysis was performed in 3,716 Chinese pan-cancer patients who underwent NGS sequencing using a 539 gene panel. The TMB calculation included synonymous and nonsynonymous mutations and InDels. MSI analysis was performed in 3,110 patients. MSI-H was defined as above 10% positive of the 195 tested microsatellites sites. The PD-L1 expression analysis was performed in 3,415 patients with immunohistochemistry staining (IHC) by antibody SP263. PD-L1 positive was defined as greater than or equal to 1%. The statistical correlation was investigated using Chi-square analysis. TMB value was compared using Wilcoxon Rank Sum test. We used TCGA public database to verify the result. Results: The mutation frequency of NFE2L2 mutation was 2.66% (99/3716). The TOP 5 cancer types were liver cancer 3.53% (14/397), lung cancer 2.97% (42/1416), colorectal cancer 2.02% (7/347), gastric cancer 1.36% (3/221), soft tissue sarcoma 0.53% (1/189). NFE2L2-MT had a significant correlation with higher TMB (p = 2.2e-16), compared with NFE2L2 wild-type (NFE2L2-WT). Among 3110 samples with MSI status, the MSI-H percentage of NFE2L2-MT and NFE2L2-WT were 8.60% (8/93) and 1.33% (40/3017), respectively (p = 1.29e-7). In 3,415 patients with PD-L1 protein expression information, the PD-L1 positive percentage of NFE2L2-MT and NFE2L2-WT were 51.52% (51/99) and 61.9% (1,268/2,048), respectively. NFE2L2-WT has higher PD-L1 positive percentage than NFE2L2-MT (p = 0.01). NFE2L2-MT was significantly correlated with higher TMB and MSI when we used TCGA data to verify, p<0.0001. However, the survival analysis of 1661 MSKCC immunotherapy cohort showed that the median OS of NFE2L2-MT vs NFE2L2-WT was 21 months vs 18 months (p=0.858), but the difference was not significant. Conclusions: NFE2L2 mutation has a very significant correlation with higher TMB and MSI, but not related to PD-L1 expression. However, whether NFE2L2-MT is related to the efficacy of immunotherapy was still unclear and more clinical data were needed.


2019 ◽  
Author(s):  
Ramlogan Sowamber ◽  
Rania Chehade ◽  
Mahmoud Bitar ◽  
Leah Dodds ◽  
Anca Milea ◽  
...  

AbstractC/EBPδ(CEBPD), a gene part of the highly conserved basic-leucine zipper (b-ZIP) domain of transcriptional factors, is downregulated in 65% of high grade serous carcinoma of the ovary (HGSC). Overexpression ofC/EBPδin different tumors as glioblastoma and breast cancer either promotes tumor progression or inhibits growth. Despite these contradictory roles in different cancer types, we show thatC/EBPδoverexpression has a consistent function of downregulating proliferation and promoting migration in fallopian tube epithelial cells (FTE). We show that the FTE have both mesenchymal and epithelial cell characteristics. Further, our data supports a role forC/EBPδas an early regulatory transcriptional factor that promotes a mesenchymal to epithelial (MET) phenotype by upregulating E-cadherin and downregulating vimentin and N-cadherin in FTE cells. We demonstrate that overexpression ofC/EBPδin ovarian and breast cancer cell lines have consistent effects and phenotype as the FTE cells. Our findings suggest a role forC/EBPδin the early events of ovarian serous carcinogenesis which may be used to help further understand how the disease develops from a premalignant cells.


2018 ◽  
Author(s):  
Krissie Lenting ◽  
Corina N.A.M. van den Heuvel ◽  
Anne van Ewijk ◽  
Elizabeth Tindall ◽  
Ge Wei ◽  
...  

AbstractHundreds of biology-based precision drugs are available that neutralize aberrant molecular pathways in cancer. Molecular heterogeneity and the lack of reliable companion diagnostic biomarkers for many drugs makes targeted treatment of cancer inaccurate for many individuals, leading to futile overtreatment. To acquire a comprehensive insight in aberrant actionable biological pathways in individual cancers we applied a cost-effective targeted RNA next generation sequencing (NGS) technique. The test allows NGS-based measurement of transcript levels and splice variants of hundreds of genes with established roles in the biological behavior in many cancer types. We here present proof of concept that the technique generates a correct molecular diagnosis and a prognosis for glioma patients. The test not only confirmed known brain cancer-associated molecular aberrations but also identified aberrant expression levels of actionable genes and mutations that are associated with other cancer types. Targeted RNA-NGS is therefore a highly attractive method to guide precision therapy for the individual patient based on pathway analysis.


2020 ◽  
Vol 21 (1) ◽  
pp. 33-43 ◽  
Author(s):  
Prasuja Rokkam ◽  
Shailender Gugalavath ◽  
Deepak Kakara Gift Kumar ◽  
Rahul Kumar Vempati ◽  
Rama Rao Malla

Glioma-associated oncogene homolog 1 (GLI1) is reported as an amplified gene in human glioblastoma cells. It is a krupple like transcription factor, belonging to the zinc finger family. The basic function of GLI1 is normal neural development at various stages of human. The GLI1 gene was first mapped on the chromosome sub-bands 12q13.3-14.1. Further, single nucleotide polymorphism is mostly observed in translating a region of 5’ and 3’- UTR of GLI1 gene in addition to two post-transcriptional splice variants, GLIΔN and tGLI. Additionally, it also regulates a plethora of gene which mediates crucial cellular processes like proliferation, differentiation, oncogenesis, EMT, and metastasis. It also regulates tumor tolerance, chemoresistance, and radioresistance. Aberrant expression of GLI1 predicts the poor survival of breast cancer patients. GLI1 is an essential mediator of the SHH signaling pathway regulating self-renewal of stem cells, angiogenesis, and expression of FOXS1, CYR61. GLI1 mediated HH pathway can induce apoptosis. Hence, GLI1 can be a future diagnostic, prognostic marker, and as well as a potent target of therapeutics in breast cancer.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2118
Author(s):  
Yusuke Hosoya ◽  
Junko Ohkanda

Intrinsically disordered proteins (IDPs) are critical players in the dynamic control of diverse cellular processes, and provide potential new drug targets because their dysregulation is closely related to many diseases. This review focuses on several medicinal studies that have identified low-molecular-weight inhibitors of IDPs. In addition, clinically relevant liquid–liquid phase separations—which critically involve both intermolecular interactions between IDPs and their posttranslational modification—are analyzed to understand the potential of IDPs as new drug targets.


Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 466
Author(s):  
Chen Chen ◽  
Samuel Haddox ◽  
Yue Tang ◽  
Fujun Qin ◽  
Hui Li

Gene fusions and their products (RNA and protein) have been traditionally recognized as unique features of cancer cells and are used as ideal biomarkers and drug targets for multiple cancer types. However, recent studies have demonstrated that chimeric RNAs generated by intergenic alternative splicing can also be found in normal cells and tissues. In this study, we aim to identify chimeric RNAs in different non-neoplastic cell lines and investigate the landscape and expression of these novel candidate chimeric RNAs. To do so, we used HEK-293T, HUVEC, and LO2 cell lines as models, performed paired-end RNA sequencing, and conducted analyses for chimeric RNA profiles. Several filtering criteria were applied, and the landscape of chimeric RNAs was characterized at multiple levels and from various angles. Further, we experimentally validated 17 chimeric RNAs from different classifications. Finally, we examined a number of validated chimeric RNAs in different cancer and non-cancer cells, including blood from healthy donors, and demonstrated their ubiquitous expression pattern.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Na Sang ◽  
Hui Liu ◽  
Bin Ma ◽  
Xianzhong Huang ◽  
Lu Zhuo ◽  
...  

Abstract Background In plants, 14-3-3 proteins, also called GENERAL REGULATORY FACTORs (GRFs), encoded by a large multigene family, are involved in protein–protein interactions and play crucial roles in various physiological processes. No genome-wide analysis of the GRF gene family has been performed in cotton, and their functions in flowering are largely unknown. Results In this study, 17, 17, 31, and 17 GRF genes were identified in Gossypium herbaceum, G. arboreum, G. hirsutum, and G. raimondii, respectively, by genome-wide analyses and were designated as GheGRFs, GaGRFs, GhGRFs, and GrGRFs, respectively. A phylogenetic analysis revealed that these proteins were divided into ε and non-ε groups. Gene structural, motif composition, synteny, and duplicated gene analyses of the identified GRF genes provided insights into the evolution of this family in cotton. GhGRF genes exhibited diverse expression patterns in different tissues. Yeast two-hybrid and bimolecular fluorescence complementation assays showed that the GhGRFs interacted with the cotton FLOWERING LOCUS T homologue GhFT in the cytoplasm and nucleus, while they interacted with the basic leucine zipper transcription factor GhFD only in the nucleus. Virus-induced gene silencing in G. hirsutum and transgenic studies in Arabidopsis demonstrated that GhGRF3/6/9/15 repressed flowering and that GhGRF14 promoted flowering. Conclusions Here, 82 GRF genes were identified in cotton, and their gene and protein features, classification, evolution, and expression patterns were comprehensively and systematically investigated. The GhGRF3/6/9/15 interacted with GhFT and GhFD to form florigen activation complexs that inhibited flowering. However, GhGRF14 interacted with GhFT and GhFD to form florigen activation complex that promoted flowering. The results provide a foundation for further studies on the regulatory mechanisms of flowering.


Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 433
Author(s):  
Bijesh George ◽  
P. Mukundan Pillai ◽  
Aswathy Mary Paul ◽  
Revikumar Amjesh ◽  
Kim Leitzel ◽  
...  

To define the growing significance of cellular targets and/or effectors of cancer drugs, we examined the fitness dependency of cellular targets and effectors of cancer drug targets across human cancer cells from 19 cancer types. We observed that the deletion of 35 out of 47 cellular effectors and/or targets of oncology drugs did not result in the expected loss of cell fitness in appropriate cancer types for which drugs targeting or utilizing these molecules for their actions were approved. Additionally, our analysis recognized 43 cellular molecules as fitness genes in several cancer types in which these drugs were not approved, and thus, providing clues for repurposing certain approved oncology drugs in such cancer types. For example, we found a widespread upregulation and fitness dependency of several components of the mevalonate and purine biosynthesis pathways (currently targeted by bisphosphonates, statins, and pemetrexed in certain cancers) and an association between the overexpression of these molecules and reduction in the overall survival duration of patients with breast and other hard-to-treat cancers, for which such drugs are not approved. In brief, the present analysis raised cautions about off-target and undesirable effects of certain oncology drugs in a subset of cancers where the intended cellular effectors of drug might not be good fitness genes and that this study offers a potential rationale for repurposing certain approved oncology drugs for targeted therapeutics in additional cancer types.


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