Benign hereditary chorea and deletions outside NKX2-1: What's the role of MBIP?

MBIP promotes ESCC metastasis by activating MAPK pathway

MBIP is a component of the Ada2A containing complex (ATAC) and has been identified as a susceptibility gene in several cancers. However, the role and molecular mechanism of MBIP in esophageal squamous cell carcinoma (ESCC) remain unclear. Our finding indicated that the expression level of MBIP in ESCC was higher than that in normal tissue (P < 0.05) based on the data from the Cancer Gene Atlas (TCGA) and Gene Expression Omnibus (GEO). Kaplan-Meier analysis showed that high MBIP expression was closely associated with deeper invasion and worse prognosis. Transwell assay and mouse xenograft assay demonstrated that MBIP overexpression promoted migration and invasion in vitro and in vivo, while MBIP knockdown played the opposite role. Furthermore, the results of RNA-seq, qRT-PCR, western blotting and rescue experiments revealed that MBIP promoted epithelial-mesenchymal transition (EMT) via the phosphorylation JNK/p38 in ESCC. Our study indicates that MBIP plays a significant role in the prognosis and metastasis of ESCC, suggesting that MBIP might serve as an ESCC prognostic biomarker.

Dosage amplification dictates oncogenic regulation by the NKX2-1 lineage factor in lung adenocarcinoma

Amplified oncogene expression is a critical and widespread driver event in cancer, yet our understanding of how amplification-mediated elevated dosage mediates oncogenic regulation is limited. Here, we find that the most significant focal amplification event in lung adenocarcinoma (LUAD) targets a lineage super-enhancer near the NKX2-1 lineage transcription factor. The NKX2-1 super-enhancer is targeted by focal and co-amplification with NKX2-1, and activation or repression controls NKX2-1 expression. We find that NKX2-1 is a widespread dependency in LUAD cell lines, where NKX2-1 pioneers enhancer accessibility to drive a lineage addicted state in LUAD, and NKX2-1 confers persistence to EGFR inhibitors. Notably, we find that oncogenic NKX2-1 regulation requires expression above a minimum dosage threshold-NKX2-1 dosage below this threshold is insufficient for cell viability, enhancer remodeling, and TKI persistence. Our data suggest that copy-number amplification can be a gain-of-function alteration, wherein amplification elevates oncogene expression above a critical dosage required for oncogenic regulation and cancer cell survival.

Thyroid Transcription Factor-1: Structure, Expression, Function and Its Relationship with Disease

Thyroid transcription factor-1 (TTF-1/NKx2.1) is a member of the NKx2 tissue-specific transcription factor family, which is expressed in thyroid follicle, parathyroid gland, alveolar epithelium, and diencephalon which originated from ectoderm, and participates in the differentiation, development, and functional maintenance of the above organs. Recent studies have shown that the abnormal expression of TTF-1 is closely related to the occurrence of a variety of human diseases and can be used as a potential new target for the diagnosis and treatment of related diseases. In this article, in order to strengthen the systematic understanding of TTF-1 and promote the progress of related research, we reviewed the structure, expression regulation, biological functions of TTF-1, and its role in the occurrence and development of human-related clinical diseases. Meanwhile, we prospect the future research direction of TTF-1, which might ultimately contribute to the understanding of the pathogenesis of related clinical diseases and the development of new prevention and treatment strategies.

Deletion of conserved non-coding sequences downstream from NKX2-1: A novel disease-causing mechanism for benign hereditary chorea

Background

Benign hereditary chorea (BHC) is an autosomal dominant disorder characterized by early‐onset non‐progressive involuntary movements. Although NKX2‐1 mutations or deletions are the cause of BHC, some BHC families do not have pathogenic alterations in the NKX2‐1 gene, indicating that mutations of non‐coding regulatory elements of NKX2‐1 may also play a role.

Methods and Results

By using whole‐genome microarray analysis, we identified a 117 Kb founder deletion in three apparently unrelated BHC families that were negative for NKX2‐1 sequence variants. Targeted next generation sequencing analysis confirmed the deletion and showed that it was part of a complex local genomic rearrangement. In addition, we also detected a 648 Kb de novo deletion in an isolated BHC case. Both deletions are located downstream from NKX2‐1 on chromosome 14q13.2‐q13.3 and share a 33 Kb smallest region of overlap with six previously reported cases. This region has no gene but contains multiple evolutionarily highly conserved non‐coding sequences.

Conclusion

We propose that the deletion of potential regulatory elements necessary for NKX2‐1 expression in this critical region is responsible for BHC phenotype in these patients, and this is a novel disease‐causing mechanism for BHC.