Browsing by Subject "NFX1-123"

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    High Expression of NFX1-123 in HPV Positive Head and Neck Squamous Cell Carcinomas
    (Wiley, 2022) Chintala, Sreenivasulu; Quist, Kevin M.; Gonzalez-DeWhitt, Patricia A.; Katzenellenbogen, Rachel A.; Pediatrics, School of Medicine
    Background: High-risk human papillomaviruses (HR HPV) cause nearly all cervical cancers and, in the United States, the majority of head and neck cancers (HNSCCs). NFX1-123 is overexpressed in cervical cancers, and NFX1-123 partners with the HR HPV type 16 E6 oncoprotein to affect multiple growth, differentiation, and immune response genes. However, neither the expression of NFX1-123 nor the levels of these genes have been investigated in HPV positive (HPV+) or negative (HPV-) HNSCCs. Methods: The Cancer Genome Atlas Splicing Variants Database and HNSCC cell lines were used to quantify expression of NFX1-123 and cellular genes increased in cervical cancers. Results: NFX1-123 was increased in HPV+ HNSCCs compared to HPV- HNSCCs. LCE1B, KRT16, SPRR2G, and FBN2 were highly expressed in HNSCCs compared to normal tissues. Notch1 and CCNB1IP1 had greater expression in HPV+ HNSCCs compared to HPV- HNSCCs. Conclusion: NFX1-123 and a subset of its known targets were increased in HPV+ HNSCCs.
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    HPV type 16 E6 and NFX1-123 Augment JNK Signaling to Mediate Keratinocyte Differentiation and L1 Expression
    (Elsevier, 2019-03-16) Levan, Justine; Vliet-Gregg, Portia A.; Robinson, Kristin L.; Matsumoto, Lisa R.; Katzenellenbogen, Rachel A.; Pediatrics, School of Medicine
    The HPV life cycle is differentiation-dependent, with cellular differentiation driving initiation of the late, productive stage of the viral life cycle. Here, we identify a role for the protein NFX1-123 in regulating keratinocyte differentiation and events of the late HPV life cycle. NFX1-123 itself increased with differentiation of epithelial cells. Greater NFX1-123 augmented differentiation marker expression and JNK phosphorylation in differentiating 16E6-expressing human foreskin keratinocytes (16E6 HFKs). This was associated with altered expression of MKK4 and MKK7, upstream kinase regulators of JNK phosphorylation. Modulating levels of NFX1-123 in HPV16-positive W12E cells recapitulated the effects on differentiation markers, JNK phosphorylation, and MKK4/7 seen in 16E6 HFKs. Crucially, levels of NFX1-123 also correlated with expression of L1, the capsid protein of HPV. Altogether, these studies define a role for NFX1-123 in mediating epithelial differentiation through the JNK signaling pathway, potentially linking expression of cellular genes and HPV genes during differentiation.
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    Longitudinal Keratinocyte Proliferation Induced by Human Papillomavirus 16E6 and NFX1-123 Partnership
    (2025-04) Billingsley, Caylin Leann; Katzenellenbogen, Rachel; Androphy, Elliot; Mosley, Amber; Robinson, Christopher
    High-risk human papillomaviruses (HPV) cause cervical, anogenital, and head and neck cancers. Despite the availability of preventive HPV vaccines, their poor uptake leaves most men and women at risk for these cancers, many of which remain common globally and others that are increasing domestically. The HPV 16 E6 (16E6) protein plays a significant role in inducing and maintaining cellular transformation of its infected host cell; however, 16E6 itself has no enzymatic activity and carries out most of its functions through partnerships with host endogenous proteins. Previously, it was demonstrated that 16E6 binds to the host protein NFX1-123, and NFX1-123 expression is increased in HPV 16 positive cervical cancer cell lines and primary cancers compared to normal tissues. In this thesis, we quantify the growth rates of 16E6-expressing keratinocytes with endogenous or overexpressed NFX1-123 (16E6/vec and 16E6/FN123, respectively) levels by measuring population doublings and interrogate whether proteome expression changes occur early or late in longitudinal growth assays that began with higher levels of NFX1-123. Early passage 16E6/vec and 16E6/FN123 cells showed similar growth rates; however, late passage 16E6/FN123 cells had accelerated growth and greater population doublings than the 16E6/vec cells. Mass spectrometry revealed similar proteomes of both cell lines at early passages. In contrast, late passaged cells had significantly higher amounts of differentially expressed protein among 16E6/FN123 and 16E6/vec cells. This indicates a unique proteomic landscape induced by the 16E6/NFX1-123 partnership. Pathway analysis vii showed increased positive telomere regulation, DNA repair, and DNA replication pathways in the late passage 16E6/FN123 cells compared to 16E6/vec. These findings indicate that the 16E6 and NFX1-123 partnership, especially with higher levels of NFX1-123, alters the longitudinal cellular environment in a manner that may initiate a preneoplastic phenotype. Additionally, the work detailed in this dissertation provides the first evidence of NFX1-123 being a direct RNA-binding protein giving new insights into the endogenous roles of the protein.
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    NFX1-123 is highly expressed in cervical cancer and increases growth and telomerase activity in HPV 16E6 expressing cells
    (Elsevier, 2019-05-01) Vliet-Gregg, Portia A.; Robinson, Kristin L.; Levan, Justine; Matsumot, Lisa R.; Katzenellenbogen, Rachel A.; Pediatrics, School of Medicine
    A significant contributor to women’s cancer mortality worldwide is cervical cancer, which is caused by high-risk human papillomavirus (HR HPV). The two viral oncoproteins of HR HPV, E6 and E7, partner with host cell proteins to target oncogenic proteins and pathways. Previously, we have shown HR HPV type 16 E6 (16E6) interacts with the host protein NFX1-123 to target telomerase and cellular immortalization, requiring NFX1-123 to fully upregulate telomerase activity. We now report that NFX1-123 is highly expressed in primary cervical cancers. In vitro, cells expressing 16E6 and overexpressing NFX1-123 have extended active growth, decreased senescence marker staining, and more rapid cell cycling compared to 16E6 expressing cells with endogenous amounts of NFX1-123. These findings were associated with increased telomerase activity and augmented expression of its catalytic subunit, hTERT. In complement, HPV 16 positive cervical cancer cell lines with knocked down NFX1-123 had slowed growth and reduced hTERT over time. In cells that express HR HPV E6, greater expression of NFX1-123 can modify active cellular growth and augment hTERT expression and telomerase activity over time, potentially supporting the initiation and progression of HPV-associated cancers.