Involvement of Hepatic Nuclear Factor I Binding Motif in Transcriptional Regulation of Ca2+-Binding Protein Regucalcin Gene

Abstract Hematopoietic stem and progenitor cells (HSPC) are routinely exploited in the clinic to treat patients with cancers or other hematologic diseases. The transcription factor nuclear factor I-X (NFIX) has a proven role regulating migration, adhesion, differentiation and quiescence in neural stem cells. Importantly, Nfix was recently shown to be upregulated in FLT3-ITD+ acute myeloid leukemia (AML) patient samples and the NFI binding motif was protected during DNase hypersensitivity screening. We recently identified Nfix as a novel regulator of HSPC repopulating potential. Using our mouse models, Nfixflox/floxRosa26-CreERT2 and Nfix+/+Rosa26-CreERT2, we induced the deletion of Nfix and performed competitive transplants; here we observe a 50% increase in chimerism 20 weeks post-transplant accompanied by a 10% increase in reconstitution of peripheral blood (PB) B cells. Primary recipient whole bone marrow (WBM) was then transplanted into secondary recipients. Beginning four weeks post-transplant, a 2.5-fold loss of PB myeloid reconstitution was observed in secondary recipients of Nfix-deficient WBM. This effect persisted beyond 20 weeks post-secondary transplant, suggesting that a self-renewing myeloid-biased HSPC is functionally perturbed by the loss of Nfix. To identify genes transcriptionally regulated by NFIX, we recently validated an anti-NFIX monoclonal antibody that is currently being used for chromatin immunoprecipitation (ChIP) followed by paired-end sequencing. Future efforts will focus on investigating Nfix-deficient myeloid-biased HSC subsets. This study will illuminate the transcriptional control of specific HSC subsets. Disclosures No relevant conflicts of interest to declare.

Download Full-text

Nuclear Factor I A Promotes Temozolomide Resistance in Glioblastoma via Transcriptional Regulation of Nuclear Factor κB Pathway

10.21203/rs.2.11554/v1 ◽

2019 ◽

Author(s):

Xiao Yu ◽

Maode Wang ◽

Jie Zuo ◽

Alafate Wahafu ◽

Ruichun Li ◽

...

Keyword(s):

Transcriptional Regulation ◽

Molecular Mechanisms ◽

Bioinformatic Analysis ◽

Therapy Resistance ◽

Nuclear Factor Κb ◽

Adverse Outcomes ◽

Nuclear Factor ◽

Factor I ◽

Nuclear Factor I

Abstract Background: Glioma is one of the most common primary brain tumors in human with severe mortality based on its therapy resistance and recurrence. Many molecular pathways and regulation factors have been proved to be required for GBM growth and therapy resistance, however, the underlying molecular mechanisms still remains unclear. Methods: Nuclear factor I-A (NFIA) was identified as a key candidate kinase encoding gene in chemoresistance regulation by using kinome-wide bioinformatic analysis. Afterwards, the potential biological functions of NFIA in oncogenesis and chemoresistance were clarified by qRT-PCR, western blotting and in vivo xenograft models followed by temozolomide (TMZ) resistant U87 cell induction. Additionally, immunohistochemistry (IHC) assays were performed to explore the clinical significance of AURKB in glioma patients. At last, lentiviral silencing of NFIA was used to explore the potential downstream targets for NFIA in acquired TMZ resistance in GBM.. Results: We identified NFIA was the most correlated gene for TMZ resistance in GBM. Clinically, elevated NFIA expression was significantly correlated to adverse outcomes of glioma patients especially in GBM patients. Moreover, NFIA was functionally required for TMZ resistance of U87 cells while suppression of NFIA via lentivirus infection reduced cell proliferation, tumorigenesis as well as resistance to TMZ in GBM cells. Lastly, NFIA promoted acquired TMZ resistance in GBM via transcription activity thus regulated the expression of nuclear factor κB (NF-kB). Conclusions: Altogether, our study suggests that NFIA-dependent transcriptional regulation of NF-kB contributes to the acquired TMZ resistance in GBM, indicating that NFIA-NF-κB axis could be a new therapeutic target for TMZ resistant GBM.

Download Full-text